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5365 lines
146 KiB
C
5365 lines
146 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
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* Written by Alex Tomas <alex@clusterfs.com>
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*/
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/*
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* mballoc.c contains the multiblocks allocation routines
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*/
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#include "ext4_jbd2.h"
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#include "mballoc.h"
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#include <linux/log2.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/nospec.h>
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#include <linux/backing-dev.h>
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#include <trace/events/ext4.h>
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#ifdef CONFIG_EXT4_DEBUG
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ushort ext4_mballoc_debug __read_mostly;
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module_param_named(mballoc_debug, ext4_mballoc_debug, ushort, 0644);
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MODULE_PARM_DESC(mballoc_debug, "Debugging level for ext4's mballoc");
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#endif
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/*
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* MUSTDO:
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* - test ext4_ext_search_left() and ext4_ext_search_right()
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* - search for metadata in few groups
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*
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* TODO v4:
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* - normalization should take into account whether file is still open
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* - discard preallocations if no free space left (policy?)
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* - don't normalize tails
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* - quota
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* - reservation for superuser
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*
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* TODO v3:
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* - bitmap read-ahead (proposed by Oleg Drokin aka green)
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* - track min/max extents in each group for better group selection
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* - mb_mark_used() may allocate chunk right after splitting buddy
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* - tree of groups sorted by number of free blocks
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* - error handling
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*/
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/*
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* The allocation request involve request for multiple number of blocks
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* near to the goal(block) value specified.
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*
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* During initialization phase of the allocator we decide to use the
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* group preallocation or inode preallocation depending on the size of
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* the file. The size of the file could be the resulting file size we
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* would have after allocation, or the current file size, which ever
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* is larger. If the size is less than sbi->s_mb_stream_request we
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* select to use the group preallocation. The default value of
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* s_mb_stream_request is 16 blocks. This can also be tuned via
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* /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
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* terms of number of blocks.
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*
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* The main motivation for having small file use group preallocation is to
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* ensure that we have small files closer together on the disk.
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*
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* First stage the allocator looks at the inode prealloc list,
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* ext4_inode_info->i_prealloc_list, which contains list of prealloc
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* spaces for this particular inode. The inode prealloc space is
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* represented as:
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*
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* pa_lstart -> the logical start block for this prealloc space
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* pa_pstart -> the physical start block for this prealloc space
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* pa_len -> length for this prealloc space (in clusters)
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* pa_free -> free space available in this prealloc space (in clusters)
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*
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* The inode preallocation space is used looking at the _logical_ start
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* block. If only the logical file block falls within the range of prealloc
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* space we will consume the particular prealloc space. This makes sure that
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* we have contiguous physical blocks representing the file blocks
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*
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* The important thing to be noted in case of inode prealloc space is that
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* we don't modify the values associated to inode prealloc space except
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* pa_free.
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*
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* If we are not able to find blocks in the inode prealloc space and if we
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* have the group allocation flag set then we look at the locality group
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* prealloc space. These are per CPU prealloc list represented as
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*
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* ext4_sb_info.s_locality_groups[smp_processor_id()]
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*
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* The reason for having a per cpu locality group is to reduce the contention
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* between CPUs. It is possible to get scheduled at this point.
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*
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* The locality group prealloc space is used looking at whether we have
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* enough free space (pa_free) within the prealloc space.
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*
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* If we can't allocate blocks via inode prealloc or/and locality group
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* prealloc then we look at the buddy cache. The buddy cache is represented
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* by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
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* mapped to the buddy and bitmap information regarding different
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* groups. The buddy information is attached to buddy cache inode so that
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* we can access them through the page cache. The information regarding
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* each group is loaded via ext4_mb_load_buddy. The information involve
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* block bitmap and buddy information. The information are stored in the
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* inode as:
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*
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* { page }
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* [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
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*
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*
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* one block each for bitmap and buddy information. So for each group we
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* take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
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* blocksize) blocks. So it can have information regarding groups_per_page
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* which is blocks_per_page/2
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*
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* The buddy cache inode is not stored on disk. The inode is thrown
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* away when the filesystem is unmounted.
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*
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* We look for count number of blocks in the buddy cache. If we were able
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* to locate that many free blocks we return with additional information
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* regarding rest of the contiguous physical block available
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*
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* Before allocating blocks via buddy cache we normalize the request
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* blocks. This ensure we ask for more blocks that we needed. The extra
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* blocks that we get after allocation is added to the respective prealloc
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* list. In case of inode preallocation we follow a list of heuristics
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* based on file size. This can be found in ext4_mb_normalize_request. If
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* we are doing a group prealloc we try to normalize the request to
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* sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
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* dependent on the cluster size; for non-bigalloc file systems, it is
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* 512 blocks. This can be tuned via
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* /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
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* terms of number of blocks. If we have mounted the file system with -O
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* stripe=<value> option the group prealloc request is normalized to the
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* the smallest multiple of the stripe value (sbi->s_stripe) which is
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* greater than the default mb_group_prealloc.
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*
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* The regular allocator (using the buddy cache) supports a few tunables.
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*
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* /sys/fs/ext4/<partition>/mb_min_to_scan
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* /sys/fs/ext4/<partition>/mb_max_to_scan
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* /sys/fs/ext4/<partition>/mb_order2_req
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*
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* The regular allocator uses buddy scan only if the request len is power of
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* 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
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* value of s_mb_order2_reqs can be tuned via
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* /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
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* stripe size (sbi->s_stripe), we try to search for contiguous block in
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* stripe size. This should result in better allocation on RAID setups. If
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* not, we search in the specific group using bitmap for best extents. The
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* tunable min_to_scan and max_to_scan control the behaviour here.
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* min_to_scan indicate how long the mballoc __must__ look for a best
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* extent and max_to_scan indicates how long the mballoc __can__ look for a
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* best extent in the found extents. Searching for the blocks starts with
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* the group specified as the goal value in allocation context via
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* ac_g_ex. Each group is first checked based on the criteria whether it
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* can be used for allocation. ext4_mb_good_group explains how the groups are
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* checked.
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*
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* Both the prealloc space are getting populated as above. So for the first
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* request we will hit the buddy cache which will result in this prealloc
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* space getting filled. The prealloc space is then later used for the
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* subsequent request.
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*/
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/*
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* mballoc operates on the following data:
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* - on-disk bitmap
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* - in-core buddy (actually includes buddy and bitmap)
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* - preallocation descriptors (PAs)
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*
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* there are two types of preallocations:
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* - inode
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* assiged to specific inode and can be used for this inode only.
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* it describes part of inode's space preallocated to specific
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* physical blocks. any block from that preallocated can be used
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* independent. the descriptor just tracks number of blocks left
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* unused. so, before taking some block from descriptor, one must
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* make sure corresponded logical block isn't allocated yet. this
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* also means that freeing any block within descriptor's range
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* must discard all preallocated blocks.
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* - locality group
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* assigned to specific locality group which does not translate to
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* permanent set of inodes: inode can join and leave group. space
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* from this type of preallocation can be used for any inode. thus
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* it's consumed from the beginning to the end.
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*
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* relation between them can be expressed as:
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* in-core buddy = on-disk bitmap + preallocation descriptors
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*
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* this mean blocks mballoc considers used are:
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* - allocated blocks (persistent)
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* - preallocated blocks (non-persistent)
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*
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* consistency in mballoc world means that at any time a block is either
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* free or used in ALL structures. notice: "any time" should not be read
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* literally -- time is discrete and delimited by locks.
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*
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* to keep it simple, we don't use block numbers, instead we count number of
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* blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
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*
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* all operations can be expressed as:
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* - init buddy: buddy = on-disk + PAs
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* - new PA: buddy += N; PA = N
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* - use inode PA: on-disk += N; PA -= N
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* - discard inode PA buddy -= on-disk - PA; PA = 0
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* - use locality group PA on-disk += N; PA -= N
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* - discard locality group PA buddy -= PA; PA = 0
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* note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
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* is used in real operation because we can't know actual used
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* bits from PA, only from on-disk bitmap
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*
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* if we follow this strict logic, then all operations above should be atomic.
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* given some of them can block, we'd have to use something like semaphores
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* killing performance on high-end SMP hardware. let's try to relax it using
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* the following knowledge:
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* 1) if buddy is referenced, it's already initialized
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* 2) while block is used in buddy and the buddy is referenced,
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* nobody can re-allocate that block
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* 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
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* bit set and PA claims same block, it's OK. IOW, one can set bit in
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* on-disk bitmap if buddy has same bit set or/and PA covers corresponded
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* block
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*
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* so, now we're building a concurrency table:
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* - init buddy vs.
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* - new PA
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* blocks for PA are allocated in the buddy, buddy must be referenced
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* until PA is linked to allocation group to avoid concurrent buddy init
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* - use inode PA
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* we need to make sure that either on-disk bitmap or PA has uptodate data
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* given (3) we care that PA-=N operation doesn't interfere with init
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* - discard inode PA
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* the simplest way would be to have buddy initialized by the discard
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* - use locality group PA
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* again PA-=N must be serialized with init
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* - discard locality group PA
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* the simplest way would be to have buddy initialized by the discard
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* - new PA vs.
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* - use inode PA
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* i_data_sem serializes them
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* - discard inode PA
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* discard process must wait until PA isn't used by another process
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* - use locality group PA
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* some mutex should serialize them
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* - discard locality group PA
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* discard process must wait until PA isn't used by another process
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* - use inode PA
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* - use inode PA
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* i_data_sem or another mutex should serializes them
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* - discard inode PA
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* discard process must wait until PA isn't used by another process
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* - use locality group PA
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* nothing wrong here -- they're different PAs covering different blocks
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* - discard locality group PA
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* discard process must wait until PA isn't used by another process
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*
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* now we're ready to make few consequences:
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* - PA is referenced and while it is no discard is possible
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* - PA is referenced until block isn't marked in on-disk bitmap
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* - PA changes only after on-disk bitmap
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* - discard must not compete with init. either init is done before
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* any discard or they're serialized somehow
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* - buddy init as sum of on-disk bitmap and PAs is done atomically
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*
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* a special case when we've used PA to emptiness. no need to modify buddy
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* in this case, but we should care about concurrent init
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*
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*/
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/*
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* Logic in few words:
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*
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* - allocation:
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* load group
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* find blocks
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* mark bits in on-disk bitmap
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* release group
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*
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* - use preallocation:
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* find proper PA (per-inode or group)
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* load group
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* mark bits in on-disk bitmap
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* release group
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* release PA
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*
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* - free:
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* load group
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* mark bits in on-disk bitmap
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* release group
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*
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* - discard preallocations in group:
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* mark PAs deleted
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* move them onto local list
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* load on-disk bitmap
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* load group
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* remove PA from object (inode or locality group)
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* mark free blocks in-core
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*
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* - discard inode's preallocations:
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*/
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/*
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* Locking rules
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*
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* Locks:
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* - bitlock on a group (group)
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* - object (inode/locality) (object)
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* - per-pa lock (pa)
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*
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* Paths:
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* - new pa
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* object
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* group
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*
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* - find and use pa:
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* pa
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*
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* - release consumed pa:
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* pa
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* group
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* object
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*
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* - generate in-core bitmap:
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* group
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* pa
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*
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* - discard all for given object (inode, locality group):
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* object
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* pa
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* group
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*
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* - discard all for given group:
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* group
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* pa
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* group
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* object
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*
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*/
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static struct kmem_cache *ext4_pspace_cachep;
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static struct kmem_cache *ext4_ac_cachep;
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static struct kmem_cache *ext4_free_data_cachep;
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/* We create slab caches for groupinfo data structures based on the
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* superblock block size. There will be one per mounted filesystem for
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* each unique s_blocksize_bits */
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#define NR_GRPINFO_CACHES 8
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static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
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static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
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"ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
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"ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
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"ext4_groupinfo_64k", "ext4_groupinfo_128k"
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};
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static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
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ext4_group_t group);
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static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
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ext4_group_t group);
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static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
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{
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#if BITS_PER_LONG == 64
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*bit += ((unsigned long) addr & 7UL) << 3;
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addr = (void *) ((unsigned long) addr & ~7UL);
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#elif BITS_PER_LONG == 32
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*bit += ((unsigned long) addr & 3UL) << 3;
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addr = (void *) ((unsigned long) addr & ~3UL);
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#else
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#error "how many bits you are?!"
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#endif
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return addr;
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}
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static inline int mb_test_bit(int bit, void *addr)
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{
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/*
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* ext4_test_bit on architecture like powerpc
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* needs unsigned long aligned address
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*/
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addr = mb_correct_addr_and_bit(&bit, addr);
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return ext4_test_bit(bit, addr);
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}
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static inline void mb_set_bit(int bit, void *addr)
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{
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addr = mb_correct_addr_and_bit(&bit, addr);
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ext4_set_bit(bit, addr);
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}
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static inline void mb_clear_bit(int bit, void *addr)
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{
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addr = mb_correct_addr_and_bit(&bit, addr);
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ext4_clear_bit(bit, addr);
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}
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static inline int mb_test_and_clear_bit(int bit, void *addr)
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{
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addr = mb_correct_addr_and_bit(&bit, addr);
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return ext4_test_and_clear_bit(bit, addr);
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}
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static inline int mb_find_next_zero_bit(void *addr, int max, int start)
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{
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int fix = 0, ret, tmpmax;
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addr = mb_correct_addr_and_bit(&fix, addr);
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tmpmax = max + fix;
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start += fix;
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ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
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if (ret > max)
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return max;
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return ret;
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}
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static inline int mb_find_next_bit(void *addr, int max, int start)
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{
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int fix = 0, ret, tmpmax;
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addr = mb_correct_addr_and_bit(&fix, addr);
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tmpmax = max + fix;
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start += fix;
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ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
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if (ret > max)
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return max;
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return ret;
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}
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static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
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{
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char *bb;
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BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
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BUG_ON(max == NULL);
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if (order > e4b->bd_blkbits + 1) {
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*max = 0;
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return NULL;
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}
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/* at order 0 we see each particular block */
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if (order == 0) {
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*max = 1 << (e4b->bd_blkbits + 3);
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return e4b->bd_bitmap;
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}
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bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
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*max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
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return bb;
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}
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#ifdef DOUBLE_CHECK
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static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
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int first, int count)
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{
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int i;
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struct super_block *sb = e4b->bd_sb;
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if (unlikely(e4b->bd_info->bb_bitmap == NULL))
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return;
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assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
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for (i = 0; i < count; i++) {
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if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
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ext4_fsblk_t blocknr;
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blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
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blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
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ext4_grp_locked_error(sb, e4b->bd_group,
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inode ? inode->i_ino : 0,
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blocknr,
|
|
"freeing block already freed "
|
|
"(bit %u)",
|
|
first + i);
|
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
}
|
|
mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
|
|
}
|
|
}
|
|
|
|
static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
|
|
{
|
|
int i;
|
|
|
|
if (unlikely(e4b->bd_info->bb_bitmap == NULL))
|
|
return;
|
|
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
|
|
for (i = 0; i < count; i++) {
|
|
BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
|
|
mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
|
|
}
|
|
}
|
|
|
|
static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
|
|
{
|
|
if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
|
|
unsigned char *b1, *b2;
|
|
int i;
|
|
b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
|
|
b2 = (unsigned char *) bitmap;
|
|
for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
|
|
if (b1[i] != b2[i]) {
|
|
ext4_msg(e4b->bd_sb, KERN_ERR,
|
|
"corruption in group %u "
|
|
"at byte %u(%u): %x in copy != %x "
|
|
"on disk/prealloc",
|
|
e4b->bd_group, i, i * 8, b1[i], b2[i]);
|
|
BUG();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#else
|
|
static inline void mb_free_blocks_double(struct inode *inode,
|
|
struct ext4_buddy *e4b, int first, int count)
|
|
{
|
|
return;
|
|
}
|
|
static inline void mb_mark_used_double(struct ext4_buddy *e4b,
|
|
int first, int count)
|
|
{
|
|
return;
|
|
}
|
|
static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
|
|
{
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
#ifdef AGGRESSIVE_CHECK
|
|
|
|
#define MB_CHECK_ASSERT(assert) \
|
|
do { \
|
|
if (!(assert)) { \
|
|
printk(KERN_EMERG \
|
|
"Assertion failure in %s() at %s:%d: \"%s\"\n", \
|
|
function, file, line, # assert); \
|
|
BUG(); \
|
|
} \
|
|
} while (0)
|
|
|
|
static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
|
|
const char *function, int line)
|
|
{
|
|
struct super_block *sb = e4b->bd_sb;
|
|
int order = e4b->bd_blkbits + 1;
|
|
int max;
|
|
int max2;
|
|
int i;
|
|
int j;
|
|
int k;
|
|
int count;
|
|
struct ext4_group_info *grp;
|
|
int fragments = 0;
|
|
int fstart;
|
|
struct list_head *cur;
|
|
void *buddy;
|
|
void *buddy2;
|
|
|
|
{
|
|
static int mb_check_counter;
|
|
if (mb_check_counter++ % 100 != 0)
|
|
return 0;
|
|
}
|
|
|
|
while (order > 1) {
|
|
buddy = mb_find_buddy(e4b, order, &max);
|
|
MB_CHECK_ASSERT(buddy);
|
|
buddy2 = mb_find_buddy(e4b, order - 1, &max2);
|
|
MB_CHECK_ASSERT(buddy2);
|
|
MB_CHECK_ASSERT(buddy != buddy2);
|
|
MB_CHECK_ASSERT(max * 2 == max2);
|
|
|
|
count = 0;
|
|
for (i = 0; i < max; i++) {
|
|
|
|
if (mb_test_bit(i, buddy)) {
|
|
/* only single bit in buddy2 may be 1 */
|
|
if (!mb_test_bit(i << 1, buddy2)) {
|
|
MB_CHECK_ASSERT(
|
|
mb_test_bit((i<<1)+1, buddy2));
|
|
} else if (!mb_test_bit((i << 1) + 1, buddy2)) {
|
|
MB_CHECK_ASSERT(
|
|
mb_test_bit(i << 1, buddy2));
|
|
}
|
|
continue;
|
|
}
|
|
|
|
/* both bits in buddy2 must be 1 */
|
|
MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
|
|
MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
|
|
|
|
for (j = 0; j < (1 << order); j++) {
|
|
k = (i * (1 << order)) + j;
|
|
MB_CHECK_ASSERT(
|
|
!mb_test_bit(k, e4b->bd_bitmap));
|
|
}
|
|
count++;
|
|
}
|
|
MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
|
|
order--;
|
|
}
|
|
|
|
fstart = -1;
|
|
buddy = mb_find_buddy(e4b, 0, &max);
|
|
for (i = 0; i < max; i++) {
|
|
if (!mb_test_bit(i, buddy)) {
|
|
MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
|
|
if (fstart == -1) {
|
|
fragments++;
|
|
fstart = i;
|
|
}
|
|
continue;
|
|
}
|
|
fstart = -1;
|
|
/* check used bits only */
|
|
for (j = 0; j < e4b->bd_blkbits + 1; j++) {
|
|
buddy2 = mb_find_buddy(e4b, j, &max2);
|
|
k = i >> j;
|
|
MB_CHECK_ASSERT(k < max2);
|
|
MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
|
|
}
|
|
}
|
|
MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
|
|
MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
|
|
|
|
grp = ext4_get_group_info(sb, e4b->bd_group);
|
|
list_for_each(cur, &grp->bb_prealloc_list) {
|
|
ext4_group_t groupnr;
|
|
struct ext4_prealloc_space *pa;
|
|
pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
|
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
|
|
MB_CHECK_ASSERT(groupnr == e4b->bd_group);
|
|
for (i = 0; i < pa->pa_len; i++)
|
|
MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
|
|
}
|
|
return 0;
|
|
}
|
|
#undef MB_CHECK_ASSERT
|
|
#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
|
|
__FILE__, __func__, __LINE__)
|
|
#else
|
|
#define mb_check_buddy(e4b)
|
|
#endif
|
|
|
|
/*
|
|
* Divide blocks started from @first with length @len into
|
|
* smaller chunks with power of 2 blocks.
|
|
* Clear the bits in bitmap which the blocks of the chunk(s) covered,
|
|
* then increase bb_counters[] for corresponded chunk size.
|
|
*/
|
|
static void ext4_mb_mark_free_simple(struct super_block *sb,
|
|
void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
|
|
struct ext4_group_info *grp)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
ext4_grpblk_t min;
|
|
ext4_grpblk_t max;
|
|
ext4_grpblk_t chunk;
|
|
unsigned int border;
|
|
|
|
BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
|
|
|
|
border = 2 << sb->s_blocksize_bits;
|
|
|
|
while (len > 0) {
|
|
/* find how many blocks can be covered since this position */
|
|
max = ffs(first | border) - 1;
|
|
|
|
/* find how many blocks of power 2 we need to mark */
|
|
min = fls(len) - 1;
|
|
|
|
if (max < min)
|
|
min = max;
|
|
chunk = 1 << min;
|
|
|
|
/* mark multiblock chunks only */
|
|
grp->bb_counters[min]++;
|
|
if (min > 0)
|
|
mb_clear_bit(first >> min,
|
|
buddy + sbi->s_mb_offsets[min]);
|
|
|
|
len -= chunk;
|
|
first += chunk;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cache the order of the largest free extent we have available in this block
|
|
* group.
|
|
*/
|
|
static void
|
|
mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
|
|
{
|
|
int i;
|
|
int bits;
|
|
|
|
grp->bb_largest_free_order = -1; /* uninit */
|
|
|
|
bits = sb->s_blocksize_bits + 1;
|
|
for (i = bits; i >= 0; i--) {
|
|
if (grp->bb_counters[i] > 0) {
|
|
grp->bb_largest_free_order = i;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static noinline_for_stack
|
|
void ext4_mb_generate_buddy(struct super_block *sb,
|
|
void *buddy, void *bitmap, ext4_group_t group)
|
|
{
|
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
|
|
ext4_grpblk_t i = 0;
|
|
ext4_grpblk_t first;
|
|
ext4_grpblk_t len;
|
|
unsigned free = 0;
|
|
unsigned fragments = 0;
|
|
unsigned long long period = get_cycles();
|
|
|
|
/* initialize buddy from bitmap which is aggregation
|
|
* of on-disk bitmap and preallocations */
|
|
i = mb_find_next_zero_bit(bitmap, max, 0);
|
|
grp->bb_first_free = i;
|
|
while (i < max) {
|
|
fragments++;
|
|
first = i;
|
|
i = mb_find_next_bit(bitmap, max, i);
|
|
len = i - first;
|
|
free += len;
|
|
if (len > 1)
|
|
ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
|
|
else
|
|
grp->bb_counters[0]++;
|
|
if (i < max)
|
|
i = mb_find_next_zero_bit(bitmap, max, i);
|
|
}
|
|
grp->bb_fragments = fragments;
|
|
|
|
if (free != grp->bb_free) {
|
|
ext4_grp_locked_error(sb, group, 0, 0,
|
|
"block bitmap and bg descriptor "
|
|
"inconsistent: %u vs %u free clusters",
|
|
free, grp->bb_free);
|
|
/*
|
|
* If we intend to continue, we consider group descriptor
|
|
* corrupt and update bb_free using bitmap value
|
|
*/
|
|
grp->bb_free = free;
|
|
ext4_mark_group_bitmap_corrupted(sb, group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
}
|
|
mb_set_largest_free_order(sb, grp);
|
|
|
|
clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
|
|
|
|
period = get_cycles() - period;
|
|
spin_lock(&sbi->s_bal_lock);
|
|
sbi->s_mb_buddies_generated++;
|
|
sbi->s_mb_generation_time += period;
|
|
spin_unlock(&sbi->s_bal_lock);
|
|
}
|
|
|
|
static void mb_regenerate_buddy(struct ext4_buddy *e4b)
|
|
{
|
|
int count;
|
|
int order = 1;
|
|
void *buddy;
|
|
|
|
while ((buddy = mb_find_buddy(e4b, order++, &count))) {
|
|
ext4_set_bits(buddy, 0, count);
|
|
}
|
|
e4b->bd_info->bb_fragments = 0;
|
|
memset(e4b->bd_info->bb_counters, 0,
|
|
sizeof(*e4b->bd_info->bb_counters) *
|
|
(e4b->bd_sb->s_blocksize_bits + 2));
|
|
|
|
ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
|
|
e4b->bd_bitmap, e4b->bd_group);
|
|
}
|
|
|
|
/* The buddy information is attached the buddy cache inode
|
|
* for convenience. The information regarding each group
|
|
* is loaded via ext4_mb_load_buddy. The information involve
|
|
* block bitmap and buddy information. The information are
|
|
* stored in the inode as
|
|
*
|
|
* { page }
|
|
* [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
|
|
*
|
|
*
|
|
* one block each for bitmap and buddy information.
|
|
* So for each group we take up 2 blocks. A page can
|
|
* contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
|
|
* So it can have information regarding groups_per_page which
|
|
* is blocks_per_page/2
|
|
*
|
|
* Locking note: This routine takes the block group lock of all groups
|
|
* for this page; do not hold this lock when calling this routine!
|
|
*/
|
|
|
|
static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
|
|
{
|
|
ext4_group_t ngroups;
|
|
int blocksize;
|
|
int blocks_per_page;
|
|
int groups_per_page;
|
|
int err = 0;
|
|
int i;
|
|
ext4_group_t first_group, group;
|
|
int first_block;
|
|
struct super_block *sb;
|
|
struct buffer_head *bhs;
|
|
struct buffer_head **bh = NULL;
|
|
struct inode *inode;
|
|
char *data;
|
|
char *bitmap;
|
|
struct ext4_group_info *grinfo;
|
|
|
|
mb_debug(1, "init page %lu\n", page->index);
|
|
|
|
inode = page->mapping->host;
|
|
sb = inode->i_sb;
|
|
ngroups = ext4_get_groups_count(sb);
|
|
blocksize = i_blocksize(inode);
|
|
blocks_per_page = PAGE_SIZE / blocksize;
|
|
|
|
groups_per_page = blocks_per_page >> 1;
|
|
if (groups_per_page == 0)
|
|
groups_per_page = 1;
|
|
|
|
/* allocate buffer_heads to read bitmaps */
|
|
if (groups_per_page > 1) {
|
|
i = sizeof(struct buffer_head *) * groups_per_page;
|
|
bh = kzalloc(i, gfp);
|
|
if (bh == NULL) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
} else
|
|
bh = &bhs;
|
|
|
|
first_group = page->index * blocks_per_page / 2;
|
|
|
|
/* read all groups the page covers into the cache */
|
|
for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
|
|
if (group >= ngroups)
|
|
break;
|
|
|
|
grinfo = ext4_get_group_info(sb, group);
|
|
/*
|
|
* If page is uptodate then we came here after online resize
|
|
* which added some new uninitialized group info structs, so
|
|
* we must skip all initialized uptodate buddies on the page,
|
|
* which may be currently in use by an allocating task.
|
|
*/
|
|
if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
|
|
bh[i] = NULL;
|
|
continue;
|
|
}
|
|
bh[i] = ext4_read_block_bitmap_nowait(sb, group);
|
|
if (IS_ERR(bh[i])) {
|
|
err = PTR_ERR(bh[i]);
|
|
bh[i] = NULL;
|
|
goto out;
|
|
}
|
|
mb_debug(1, "read bitmap for group %u\n", group);
|
|
}
|
|
|
|
/* wait for I/O completion */
|
|
for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
|
|
int err2;
|
|
|
|
if (!bh[i])
|
|
continue;
|
|
err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
|
|
if (!err)
|
|
err = err2;
|
|
}
|
|
|
|
first_block = page->index * blocks_per_page;
|
|
for (i = 0; i < blocks_per_page; i++) {
|
|
group = (first_block + i) >> 1;
|
|
if (group >= ngroups)
|
|
break;
|
|
|
|
if (!bh[group - first_group])
|
|
/* skip initialized uptodate buddy */
|
|
continue;
|
|
|
|
if (!buffer_verified(bh[group - first_group]))
|
|
/* Skip faulty bitmaps */
|
|
continue;
|
|
err = 0;
|
|
|
|
/*
|
|
* data carry information regarding this
|
|
* particular group in the format specified
|
|
* above
|
|
*
|
|
*/
|
|
data = page_address(page) + (i * blocksize);
|
|
bitmap = bh[group - first_group]->b_data;
|
|
|
|
/*
|
|
* We place the buddy block and bitmap block
|
|
* close together
|
|
*/
|
|
if ((first_block + i) & 1) {
|
|
/* this is block of buddy */
|
|
BUG_ON(incore == NULL);
|
|
mb_debug(1, "put buddy for group %u in page %lu/%x\n",
|
|
group, page->index, i * blocksize);
|
|
trace_ext4_mb_buddy_bitmap_load(sb, group);
|
|
grinfo = ext4_get_group_info(sb, group);
|
|
grinfo->bb_fragments = 0;
|
|
memset(grinfo->bb_counters, 0,
|
|
sizeof(*grinfo->bb_counters) *
|
|
(sb->s_blocksize_bits+2));
|
|
/*
|
|
* incore got set to the group block bitmap below
|
|
*/
|
|
ext4_lock_group(sb, group);
|
|
/* init the buddy */
|
|
memset(data, 0xff, blocksize);
|
|
ext4_mb_generate_buddy(sb, data, incore, group);
|
|
ext4_unlock_group(sb, group);
|
|
incore = NULL;
|
|
} else {
|
|
/* this is block of bitmap */
|
|
BUG_ON(incore != NULL);
|
|
mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
|
|
group, page->index, i * blocksize);
|
|
trace_ext4_mb_bitmap_load(sb, group);
|
|
|
|
/* see comments in ext4_mb_put_pa() */
|
|
ext4_lock_group(sb, group);
|
|
memcpy(data, bitmap, blocksize);
|
|
|
|
/* mark all preallocated blks used in in-core bitmap */
|
|
ext4_mb_generate_from_pa(sb, data, group);
|
|
ext4_mb_generate_from_freelist(sb, data, group);
|
|
ext4_unlock_group(sb, group);
|
|
|
|
/* set incore so that the buddy information can be
|
|
* generated using this
|
|
*/
|
|
incore = data;
|
|
}
|
|
}
|
|
SetPageUptodate(page);
|
|
|
|
out:
|
|
if (bh) {
|
|
for (i = 0; i < groups_per_page; i++)
|
|
brelse(bh[i]);
|
|
if (bh != &bhs)
|
|
kfree(bh);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Lock the buddy and bitmap pages. This make sure other parallel init_group
|
|
* on the same buddy page doesn't happen whild holding the buddy page lock.
|
|
* Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
|
|
* are on the same page e4b->bd_buddy_page is NULL and return value is 0.
|
|
*/
|
|
static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
|
|
ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
|
|
{
|
|
struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
|
|
int block, pnum, poff;
|
|
int blocks_per_page;
|
|
struct page *page;
|
|
|
|
e4b->bd_buddy_page = NULL;
|
|
e4b->bd_bitmap_page = NULL;
|
|
|
|
blocks_per_page = PAGE_SIZE / sb->s_blocksize;
|
|
/*
|
|
* the buddy cache inode stores the block bitmap
|
|
* and buddy information in consecutive blocks.
|
|
* So for each group we need two blocks.
|
|
*/
|
|
block = group * 2;
|
|
pnum = block / blocks_per_page;
|
|
poff = block % blocks_per_page;
|
|
page = find_or_create_page(inode->i_mapping, pnum, gfp);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
BUG_ON(page->mapping != inode->i_mapping);
|
|
e4b->bd_bitmap_page = page;
|
|
e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
|
|
|
|
if (blocks_per_page >= 2) {
|
|
/* buddy and bitmap are on the same page */
|
|
return 0;
|
|
}
|
|
|
|
block++;
|
|
pnum = block / blocks_per_page;
|
|
page = find_or_create_page(inode->i_mapping, pnum, gfp);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
BUG_ON(page->mapping != inode->i_mapping);
|
|
e4b->bd_buddy_page = page;
|
|
return 0;
|
|
}
|
|
|
|
static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
|
|
{
|
|
if (e4b->bd_bitmap_page) {
|
|
unlock_page(e4b->bd_bitmap_page);
|
|
put_page(e4b->bd_bitmap_page);
|
|
}
|
|
if (e4b->bd_buddy_page) {
|
|
unlock_page(e4b->bd_buddy_page);
|
|
put_page(e4b->bd_buddy_page);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Locking note: This routine calls ext4_mb_init_cache(), which takes the
|
|
* block group lock of all groups for this page; do not hold the BG lock when
|
|
* calling this routine!
|
|
*/
|
|
static noinline_for_stack
|
|
int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
|
|
{
|
|
|
|
struct ext4_group_info *this_grp;
|
|
struct ext4_buddy e4b;
|
|
struct page *page;
|
|
int ret = 0;
|
|
|
|
might_sleep();
|
|
mb_debug(1, "init group %u\n", group);
|
|
this_grp = ext4_get_group_info(sb, group);
|
|
/*
|
|
* This ensures that we don't reinit the buddy cache
|
|
* page which map to the group from which we are already
|
|
* allocating. If we are looking at the buddy cache we would
|
|
* have taken a reference using ext4_mb_load_buddy and that
|
|
* would have pinned buddy page to page cache.
|
|
* The call to ext4_mb_get_buddy_page_lock will mark the
|
|
* page accessed.
|
|
*/
|
|
ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
|
|
if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
|
|
/*
|
|
* somebody initialized the group
|
|
* return without doing anything
|
|
*/
|
|
goto err;
|
|
}
|
|
|
|
page = e4b.bd_bitmap_page;
|
|
ret = ext4_mb_init_cache(page, NULL, gfp);
|
|
if (ret)
|
|
goto err;
|
|
if (!PageUptodate(page)) {
|
|
ret = -EIO;
|
|
goto err;
|
|
}
|
|
|
|
if (e4b.bd_buddy_page == NULL) {
|
|
/*
|
|
* If both the bitmap and buddy are in
|
|
* the same page we don't need to force
|
|
* init the buddy
|
|
*/
|
|
ret = 0;
|
|
goto err;
|
|
}
|
|
/* init buddy cache */
|
|
page = e4b.bd_buddy_page;
|
|
ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
|
|
if (ret)
|
|
goto err;
|
|
if (!PageUptodate(page)) {
|
|
ret = -EIO;
|
|
goto err;
|
|
}
|
|
err:
|
|
ext4_mb_put_buddy_page_lock(&e4b);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Locking note: This routine calls ext4_mb_init_cache(), which takes the
|
|
* block group lock of all groups for this page; do not hold the BG lock when
|
|
* calling this routine!
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
|
|
struct ext4_buddy *e4b, gfp_t gfp)
|
|
{
|
|
int blocks_per_page;
|
|
int block;
|
|
int pnum;
|
|
int poff;
|
|
struct page *page;
|
|
int ret;
|
|
struct ext4_group_info *grp;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct inode *inode = sbi->s_buddy_cache;
|
|
|
|
might_sleep();
|
|
mb_debug(1, "load group %u\n", group);
|
|
|
|
blocks_per_page = PAGE_SIZE / sb->s_blocksize;
|
|
grp = ext4_get_group_info(sb, group);
|
|
|
|
e4b->bd_blkbits = sb->s_blocksize_bits;
|
|
e4b->bd_info = grp;
|
|
e4b->bd_sb = sb;
|
|
e4b->bd_group = group;
|
|
e4b->bd_buddy_page = NULL;
|
|
e4b->bd_bitmap_page = NULL;
|
|
|
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
|
|
/*
|
|
* we need full data about the group
|
|
* to make a good selection
|
|
*/
|
|
ret = ext4_mb_init_group(sb, group, gfp);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* the buddy cache inode stores the block bitmap
|
|
* and buddy information in consecutive blocks.
|
|
* So for each group we need two blocks.
|
|
*/
|
|
block = group * 2;
|
|
pnum = block / blocks_per_page;
|
|
poff = block % blocks_per_page;
|
|
|
|
/* we could use find_or_create_page(), but it locks page
|
|
* what we'd like to avoid in fast path ... */
|
|
page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
|
|
if (page == NULL || !PageUptodate(page)) {
|
|
if (page)
|
|
/*
|
|
* drop the page reference and try
|
|
* to get the page with lock. If we
|
|
* are not uptodate that implies
|
|
* somebody just created the page but
|
|
* is yet to initialize the same. So
|
|
* wait for it to initialize.
|
|
*/
|
|
put_page(page);
|
|
page = find_or_create_page(inode->i_mapping, pnum, gfp);
|
|
if (page) {
|
|
BUG_ON(page->mapping != inode->i_mapping);
|
|
if (!PageUptodate(page)) {
|
|
ret = ext4_mb_init_cache(page, NULL, gfp);
|
|
if (ret) {
|
|
unlock_page(page);
|
|
goto err;
|
|
}
|
|
mb_cmp_bitmaps(e4b, page_address(page) +
|
|
(poff * sb->s_blocksize));
|
|
}
|
|
unlock_page(page);
|
|
}
|
|
}
|
|
if (page == NULL) {
|
|
ret = -ENOMEM;
|
|
goto err;
|
|
}
|
|
if (!PageUptodate(page)) {
|
|
ret = -EIO;
|
|
goto err;
|
|
}
|
|
|
|
/* Pages marked accessed already */
|
|
e4b->bd_bitmap_page = page;
|
|
e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
|
|
|
|
block++;
|
|
pnum = block / blocks_per_page;
|
|
poff = block % blocks_per_page;
|
|
|
|
page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
|
|
if (page == NULL || !PageUptodate(page)) {
|
|
if (page)
|
|
put_page(page);
|
|
page = find_or_create_page(inode->i_mapping, pnum, gfp);
|
|
if (page) {
|
|
BUG_ON(page->mapping != inode->i_mapping);
|
|
if (!PageUptodate(page)) {
|
|
ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
|
|
gfp);
|
|
if (ret) {
|
|
unlock_page(page);
|
|
goto err;
|
|
}
|
|
}
|
|
unlock_page(page);
|
|
}
|
|
}
|
|
if (page == NULL) {
|
|
ret = -ENOMEM;
|
|
goto err;
|
|
}
|
|
if (!PageUptodate(page)) {
|
|
ret = -EIO;
|
|
goto err;
|
|
}
|
|
|
|
/* Pages marked accessed already */
|
|
e4b->bd_buddy_page = page;
|
|
e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
|
|
|
|
BUG_ON(e4b->bd_bitmap_page == NULL);
|
|
BUG_ON(e4b->bd_buddy_page == NULL);
|
|
|
|
return 0;
|
|
|
|
err:
|
|
if (page)
|
|
put_page(page);
|
|
if (e4b->bd_bitmap_page)
|
|
put_page(e4b->bd_bitmap_page);
|
|
if (e4b->bd_buddy_page)
|
|
put_page(e4b->bd_buddy_page);
|
|
e4b->bd_buddy = NULL;
|
|
e4b->bd_bitmap = NULL;
|
|
return ret;
|
|
}
|
|
|
|
static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
|
|
}
|
|
|
|
static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
|
|
{
|
|
if (e4b->bd_bitmap_page)
|
|
put_page(e4b->bd_bitmap_page);
|
|
if (e4b->bd_buddy_page)
|
|
put_page(e4b->bd_buddy_page);
|
|
}
|
|
|
|
|
|
static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
|
|
{
|
|
int order = 1;
|
|
int bb_incr = 1 << (e4b->bd_blkbits - 1);
|
|
void *bb;
|
|
|
|
BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
|
|
BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
|
|
|
|
bb = e4b->bd_buddy;
|
|
while (order <= e4b->bd_blkbits + 1) {
|
|
block = block >> 1;
|
|
if (!mb_test_bit(block, bb)) {
|
|
/* this block is part of buddy of order 'order' */
|
|
return order;
|
|
}
|
|
bb += bb_incr;
|
|
bb_incr >>= 1;
|
|
order++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void mb_clear_bits(void *bm, int cur, int len)
|
|
{
|
|
__u32 *addr;
|
|
|
|
len = cur + len;
|
|
while (cur < len) {
|
|
if ((cur & 31) == 0 && (len - cur) >= 32) {
|
|
/* fast path: clear whole word at once */
|
|
addr = bm + (cur >> 3);
|
|
*addr = 0;
|
|
cur += 32;
|
|
continue;
|
|
}
|
|
mb_clear_bit(cur, bm);
|
|
cur++;
|
|
}
|
|
}
|
|
|
|
/* clear bits in given range
|
|
* will return first found zero bit if any, -1 otherwise
|
|
*/
|
|
static int mb_test_and_clear_bits(void *bm, int cur, int len)
|
|
{
|
|
__u32 *addr;
|
|
int zero_bit = -1;
|
|
|
|
len = cur + len;
|
|
while (cur < len) {
|
|
if ((cur & 31) == 0 && (len - cur) >= 32) {
|
|
/* fast path: clear whole word at once */
|
|
addr = bm + (cur >> 3);
|
|
if (*addr != (__u32)(-1) && zero_bit == -1)
|
|
zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
|
|
*addr = 0;
|
|
cur += 32;
|
|
continue;
|
|
}
|
|
if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
|
|
zero_bit = cur;
|
|
cur++;
|
|
}
|
|
|
|
return zero_bit;
|
|
}
|
|
|
|
void ext4_set_bits(void *bm, int cur, int len)
|
|
{
|
|
__u32 *addr;
|
|
|
|
len = cur + len;
|
|
while (cur < len) {
|
|
if ((cur & 31) == 0 && (len - cur) >= 32) {
|
|
/* fast path: set whole word at once */
|
|
addr = bm + (cur >> 3);
|
|
*addr = 0xffffffff;
|
|
cur += 32;
|
|
continue;
|
|
}
|
|
mb_set_bit(cur, bm);
|
|
cur++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* _________________________________________________________________ */
|
|
|
|
static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
|
|
{
|
|
if (mb_test_bit(*bit + side, bitmap)) {
|
|
mb_clear_bit(*bit, bitmap);
|
|
(*bit) -= side;
|
|
return 1;
|
|
}
|
|
else {
|
|
(*bit) += side;
|
|
mb_set_bit(*bit, bitmap);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
|
|
{
|
|
int max;
|
|
int order = 1;
|
|
void *buddy = mb_find_buddy(e4b, order, &max);
|
|
|
|
while (buddy) {
|
|
void *buddy2;
|
|
|
|
/* Bits in range [first; last] are known to be set since
|
|
* corresponding blocks were allocated. Bits in range
|
|
* (first; last) will stay set because they form buddies on
|
|
* upper layer. We just deal with borders if they don't
|
|
* align with upper layer and then go up.
|
|
* Releasing entire group is all about clearing
|
|
* single bit of highest order buddy.
|
|
*/
|
|
|
|
/* Example:
|
|
* ---------------------------------
|
|
* | 1 | 1 | 1 | 1 |
|
|
* ---------------------------------
|
|
* | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
|
|
* ---------------------------------
|
|
* 0 1 2 3 4 5 6 7
|
|
* \_____________________/
|
|
*
|
|
* Neither [1] nor [6] is aligned to above layer.
|
|
* Left neighbour [0] is free, so mark it busy,
|
|
* decrease bb_counters and extend range to
|
|
* [0; 6]
|
|
* Right neighbour [7] is busy. It can't be coaleasced with [6], so
|
|
* mark [6] free, increase bb_counters and shrink range to
|
|
* [0; 5].
|
|
* Then shift range to [0; 2], go up and do the same.
|
|
*/
|
|
|
|
|
|
if (first & 1)
|
|
e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
|
|
if (!(last & 1))
|
|
e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
|
|
if (first > last)
|
|
break;
|
|
order++;
|
|
|
|
if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) {
|
|
mb_clear_bits(buddy, first, last - first + 1);
|
|
e4b->bd_info->bb_counters[order - 1] += last - first + 1;
|
|
break;
|
|
}
|
|
first >>= 1;
|
|
last >>= 1;
|
|
buddy = buddy2;
|
|
}
|
|
}
|
|
|
|
static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
|
|
int first, int count)
|
|
{
|
|
int left_is_free = 0;
|
|
int right_is_free = 0;
|
|
int block;
|
|
int last = first + count - 1;
|
|
struct super_block *sb = e4b->bd_sb;
|
|
|
|
if (WARN_ON(count == 0))
|
|
return;
|
|
BUG_ON(last >= (sb->s_blocksize << 3));
|
|
assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
|
|
/* Don't bother if the block group is corrupt. */
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
|
|
return;
|
|
|
|
mb_check_buddy(e4b);
|
|
mb_free_blocks_double(inode, e4b, first, count);
|
|
|
|
e4b->bd_info->bb_free += count;
|
|
if (first < e4b->bd_info->bb_first_free)
|
|
e4b->bd_info->bb_first_free = first;
|
|
|
|
/* access memory sequentially: check left neighbour,
|
|
* clear range and then check right neighbour
|
|
*/
|
|
if (first != 0)
|
|
left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
|
|
block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
|
|
if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
|
|
right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
|
|
|
|
if (unlikely(block != -1)) {
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
ext4_fsblk_t blocknr;
|
|
|
|
blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
|
|
blocknr += EXT4_C2B(sbi, block);
|
|
ext4_grp_locked_error(sb, e4b->bd_group,
|
|
inode ? inode->i_ino : 0,
|
|
blocknr,
|
|
"freeing already freed block "
|
|
"(bit %u); block bitmap corrupt.",
|
|
block);
|
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
mb_regenerate_buddy(e4b);
|
|
goto done;
|
|
}
|
|
|
|
/* let's maintain fragments counter */
|
|
if (left_is_free && right_is_free)
|
|
e4b->bd_info->bb_fragments--;
|
|
else if (!left_is_free && !right_is_free)
|
|
e4b->bd_info->bb_fragments++;
|
|
|
|
/* buddy[0] == bd_bitmap is a special case, so handle
|
|
* it right away and let mb_buddy_mark_free stay free of
|
|
* zero order checks.
|
|
* Check if neighbours are to be coaleasced,
|
|
* adjust bitmap bb_counters and borders appropriately.
|
|
*/
|
|
if (first & 1) {
|
|
first += !left_is_free;
|
|
e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
|
|
}
|
|
if (!(last & 1)) {
|
|
last -= !right_is_free;
|
|
e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
|
|
}
|
|
|
|
if (first <= last)
|
|
mb_buddy_mark_free(e4b, first >> 1, last >> 1);
|
|
|
|
done:
|
|
mb_set_largest_free_order(sb, e4b->bd_info);
|
|
mb_check_buddy(e4b);
|
|
}
|
|
|
|
static int mb_find_extent(struct ext4_buddy *e4b, int block,
|
|
int needed, struct ext4_free_extent *ex)
|
|
{
|
|
int next = block;
|
|
int max, order;
|
|
void *buddy;
|
|
|
|
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
|
|
BUG_ON(ex == NULL);
|
|
|
|
buddy = mb_find_buddy(e4b, 0, &max);
|
|
BUG_ON(buddy == NULL);
|
|
BUG_ON(block >= max);
|
|
if (mb_test_bit(block, buddy)) {
|
|
ex->fe_len = 0;
|
|
ex->fe_start = 0;
|
|
ex->fe_group = 0;
|
|
return 0;
|
|
}
|
|
|
|
/* find actual order */
|
|
order = mb_find_order_for_block(e4b, block);
|
|
block = block >> order;
|
|
|
|
ex->fe_len = 1 << order;
|
|
ex->fe_start = block << order;
|
|
ex->fe_group = e4b->bd_group;
|
|
|
|
/* calc difference from given start */
|
|
next = next - ex->fe_start;
|
|
ex->fe_len -= next;
|
|
ex->fe_start += next;
|
|
|
|
while (needed > ex->fe_len &&
|
|
mb_find_buddy(e4b, order, &max)) {
|
|
|
|
if (block + 1 >= max)
|
|
break;
|
|
|
|
next = (block + 1) * (1 << order);
|
|
if (mb_test_bit(next, e4b->bd_bitmap))
|
|
break;
|
|
|
|
order = mb_find_order_for_block(e4b, next);
|
|
|
|
block = next >> order;
|
|
ex->fe_len += 1 << order;
|
|
}
|
|
|
|
if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
|
|
/* Should never happen! (but apparently sometimes does?!?) */
|
|
WARN_ON(1);
|
|
ext4_error(e4b->bd_sb, "corruption or bug in mb_find_extent "
|
|
"block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
|
|
block, order, needed, ex->fe_group, ex->fe_start,
|
|
ex->fe_len, ex->fe_logical);
|
|
ex->fe_len = 0;
|
|
ex->fe_start = 0;
|
|
ex->fe_group = 0;
|
|
}
|
|
return ex->fe_len;
|
|
}
|
|
|
|
static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
|
|
{
|
|
int ord;
|
|
int mlen = 0;
|
|
int max = 0;
|
|
int cur;
|
|
int start = ex->fe_start;
|
|
int len = ex->fe_len;
|
|
unsigned ret = 0;
|
|
int len0 = len;
|
|
void *buddy;
|
|
|
|
BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
|
|
BUG_ON(e4b->bd_group != ex->fe_group);
|
|
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
|
|
mb_check_buddy(e4b);
|
|
mb_mark_used_double(e4b, start, len);
|
|
|
|
e4b->bd_info->bb_free -= len;
|
|
if (e4b->bd_info->bb_first_free == start)
|
|
e4b->bd_info->bb_first_free += len;
|
|
|
|
/* let's maintain fragments counter */
|
|
if (start != 0)
|
|
mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
|
|
if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
|
|
max = !mb_test_bit(start + len, e4b->bd_bitmap);
|
|
if (mlen && max)
|
|
e4b->bd_info->bb_fragments++;
|
|
else if (!mlen && !max)
|
|
e4b->bd_info->bb_fragments--;
|
|
|
|
/* let's maintain buddy itself */
|
|
while (len) {
|
|
ord = mb_find_order_for_block(e4b, start);
|
|
|
|
if (((start >> ord) << ord) == start && len >= (1 << ord)) {
|
|
/* the whole chunk may be allocated at once! */
|
|
mlen = 1 << ord;
|
|
buddy = mb_find_buddy(e4b, ord, &max);
|
|
BUG_ON((start >> ord) >= max);
|
|
mb_set_bit(start >> ord, buddy);
|
|
e4b->bd_info->bb_counters[ord]--;
|
|
start += mlen;
|
|
len -= mlen;
|
|
BUG_ON(len < 0);
|
|
continue;
|
|
}
|
|
|
|
/* store for history */
|
|
if (ret == 0)
|
|
ret = len | (ord << 16);
|
|
|
|
/* we have to split large buddy */
|
|
BUG_ON(ord <= 0);
|
|
buddy = mb_find_buddy(e4b, ord, &max);
|
|
mb_set_bit(start >> ord, buddy);
|
|
e4b->bd_info->bb_counters[ord]--;
|
|
|
|
ord--;
|
|
cur = (start >> ord) & ~1U;
|
|
buddy = mb_find_buddy(e4b, ord, &max);
|
|
mb_clear_bit(cur, buddy);
|
|
mb_clear_bit(cur + 1, buddy);
|
|
e4b->bd_info->bb_counters[ord]++;
|
|
e4b->bd_info->bb_counters[ord]++;
|
|
}
|
|
mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
|
|
|
|
ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
|
|
mb_check_buddy(e4b);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Must be called under group lock!
|
|
*/
|
|
static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
int ret;
|
|
|
|
BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
|
|
BUG_ON(ac->ac_status == AC_STATUS_FOUND);
|
|
|
|
ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
|
|
ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
|
|
ret = mb_mark_used(e4b, &ac->ac_b_ex);
|
|
|
|
/* preallocation can change ac_b_ex, thus we store actually
|
|
* allocated blocks for history */
|
|
ac->ac_f_ex = ac->ac_b_ex;
|
|
|
|
ac->ac_status = AC_STATUS_FOUND;
|
|
ac->ac_tail = ret & 0xffff;
|
|
ac->ac_buddy = ret >> 16;
|
|
|
|
/*
|
|
* take the page reference. We want the page to be pinned
|
|
* so that we don't get a ext4_mb_init_cache_call for this
|
|
* group until we update the bitmap. That would mean we
|
|
* double allocate blocks. The reference is dropped
|
|
* in ext4_mb_release_context
|
|
*/
|
|
ac->ac_bitmap_page = e4b->bd_bitmap_page;
|
|
get_page(ac->ac_bitmap_page);
|
|
ac->ac_buddy_page = e4b->bd_buddy_page;
|
|
get_page(ac->ac_buddy_page);
|
|
/* store last allocated for subsequent stream allocation */
|
|
if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
|
|
spin_lock(&sbi->s_md_lock);
|
|
sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
|
|
sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
|
|
spin_unlock(&sbi->s_md_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* regular allocator, for general purposes allocation
|
|
*/
|
|
|
|
static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b,
|
|
int finish_group)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
struct ext4_free_extent *bex = &ac->ac_b_ex;
|
|
struct ext4_free_extent *gex = &ac->ac_g_ex;
|
|
struct ext4_free_extent ex;
|
|
int max;
|
|
|
|
if (ac->ac_status == AC_STATUS_FOUND)
|
|
return;
|
|
/*
|
|
* We don't want to scan for a whole year
|
|
*/
|
|
if (ac->ac_found > sbi->s_mb_max_to_scan &&
|
|
!(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
|
|
ac->ac_status = AC_STATUS_BREAK;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Haven't found good chunk so far, let's continue
|
|
*/
|
|
if (bex->fe_len < gex->fe_len)
|
|
return;
|
|
|
|
if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
|
|
&& bex->fe_group == e4b->bd_group) {
|
|
/* recheck chunk's availability - we don't know
|
|
* when it was found (within this lock-unlock
|
|
* period or not) */
|
|
max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
|
|
if (max >= gex->fe_len) {
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The routine checks whether found extent is good enough. If it is,
|
|
* then the extent gets marked used and flag is set to the context
|
|
* to stop scanning. Otherwise, the extent is compared with the
|
|
* previous found extent and if new one is better, then it's stored
|
|
* in the context. Later, the best found extent will be used, if
|
|
* mballoc can't find good enough extent.
|
|
*
|
|
* FIXME: real allocation policy is to be designed yet!
|
|
*/
|
|
static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
|
|
struct ext4_free_extent *ex,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
struct ext4_free_extent *bex = &ac->ac_b_ex;
|
|
struct ext4_free_extent *gex = &ac->ac_g_ex;
|
|
|
|
BUG_ON(ex->fe_len <= 0);
|
|
BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
|
|
BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
|
|
BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
|
|
|
|
ac->ac_found++;
|
|
|
|
/*
|
|
* The special case - take what you catch first
|
|
*/
|
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
|
|
*bex = *ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Let's check whether the chuck is good enough
|
|
*/
|
|
if (ex->fe_len == gex->fe_len) {
|
|
*bex = *ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If this is first found extent, just store it in the context
|
|
*/
|
|
if (bex->fe_len == 0) {
|
|
*bex = *ex;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If new found extent is better, store it in the context
|
|
*/
|
|
if (bex->fe_len < gex->fe_len) {
|
|
/* if the request isn't satisfied, any found extent
|
|
* larger than previous best one is better */
|
|
if (ex->fe_len > bex->fe_len)
|
|
*bex = *ex;
|
|
} else if (ex->fe_len > gex->fe_len) {
|
|
/* if the request is satisfied, then we try to find
|
|
* an extent that still satisfy the request, but is
|
|
* smaller than previous one */
|
|
if (ex->fe_len < bex->fe_len)
|
|
*bex = *ex;
|
|
}
|
|
|
|
ext4_mb_check_limits(ac, e4b, 0);
|
|
}
|
|
|
|
static noinline_for_stack
|
|
int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
struct ext4_free_extent ex = ac->ac_b_ex;
|
|
ext4_group_t group = ex.fe_group;
|
|
int max;
|
|
int err;
|
|
|
|
BUG_ON(ex.fe_len <= 0);
|
|
err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
|
|
if (err)
|
|
return err;
|
|
|
|
ext4_lock_group(ac->ac_sb, group);
|
|
max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
|
|
|
|
if (max > 0) {
|
|
ac->ac_b_ex = ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
}
|
|
|
|
ext4_unlock_group(ac->ac_sb, group);
|
|
ext4_mb_unload_buddy(e4b);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
ext4_group_t group = ac->ac_g_ex.fe_group;
|
|
int max;
|
|
int err;
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
|
|
struct ext4_free_extent ex;
|
|
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
|
|
return 0;
|
|
if (grp->bb_free == 0)
|
|
return 0;
|
|
|
|
err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
|
|
if (err)
|
|
return err;
|
|
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
|
|
ext4_mb_unload_buddy(e4b);
|
|
return 0;
|
|
}
|
|
|
|
ext4_lock_group(ac->ac_sb, group);
|
|
max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
|
|
ac->ac_g_ex.fe_len, &ex);
|
|
ex.fe_logical = 0xDEADFA11; /* debug value */
|
|
|
|
if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
|
|
ext4_fsblk_t start;
|
|
|
|
start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) +
|
|
ex.fe_start;
|
|
/* use do_div to get remainder (would be 64-bit modulo) */
|
|
if (do_div(start, sbi->s_stripe) == 0) {
|
|
ac->ac_found++;
|
|
ac->ac_b_ex = ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
}
|
|
} else if (max >= ac->ac_g_ex.fe_len) {
|
|
BUG_ON(ex.fe_len <= 0);
|
|
BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
|
|
BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
|
|
ac->ac_found++;
|
|
ac->ac_b_ex = ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
} else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
|
|
/* Sometimes, caller may want to merge even small
|
|
* number of blocks to an existing extent */
|
|
BUG_ON(ex.fe_len <= 0);
|
|
BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
|
|
BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
|
|
ac->ac_found++;
|
|
ac->ac_b_ex = ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
}
|
|
ext4_unlock_group(ac->ac_sb, group);
|
|
ext4_mb_unload_buddy(e4b);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* The routine scans buddy structures (not bitmap!) from given order
|
|
* to max order and tries to find big enough chunk to satisfy the req
|
|
*/
|
|
static noinline_for_stack
|
|
void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
struct ext4_group_info *grp = e4b->bd_info;
|
|
void *buddy;
|
|
int i;
|
|
int k;
|
|
int max;
|
|
|
|
BUG_ON(ac->ac_2order <= 0);
|
|
for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
|
|
if (grp->bb_counters[i] == 0)
|
|
continue;
|
|
|
|
buddy = mb_find_buddy(e4b, i, &max);
|
|
BUG_ON(buddy == NULL);
|
|
|
|
k = mb_find_next_zero_bit(buddy, max, 0);
|
|
BUG_ON(k >= max);
|
|
|
|
ac->ac_found++;
|
|
|
|
ac->ac_b_ex.fe_len = 1 << i;
|
|
ac->ac_b_ex.fe_start = k << i;
|
|
ac->ac_b_ex.fe_group = e4b->bd_group;
|
|
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
|
|
BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
|
|
|
|
if (EXT4_SB(sb)->s_mb_stats)
|
|
atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The routine scans the group and measures all found extents.
|
|
* In order to optimize scanning, caller must pass number of
|
|
* free blocks in the group, so the routine can know upper limit.
|
|
*/
|
|
static noinline_for_stack
|
|
void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
void *bitmap = e4b->bd_bitmap;
|
|
struct ext4_free_extent ex;
|
|
int i;
|
|
int free;
|
|
|
|
free = e4b->bd_info->bb_free;
|
|
BUG_ON(free <= 0);
|
|
|
|
i = e4b->bd_info->bb_first_free;
|
|
|
|
while (free && ac->ac_status == AC_STATUS_CONTINUE) {
|
|
i = mb_find_next_zero_bit(bitmap,
|
|
EXT4_CLUSTERS_PER_GROUP(sb), i);
|
|
if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
|
|
/*
|
|
* IF we have corrupt bitmap, we won't find any
|
|
* free blocks even though group info says we
|
|
* we have free blocks
|
|
*/
|
|
ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
|
|
"%d free clusters as per "
|
|
"group info. But bitmap says 0",
|
|
free);
|
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
break;
|
|
}
|
|
|
|
mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
|
|
BUG_ON(ex.fe_len <= 0);
|
|
if (free < ex.fe_len) {
|
|
ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
|
|
"%d free clusters as per "
|
|
"group info. But got %d blocks",
|
|
free, ex.fe_len);
|
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
/*
|
|
* The number of free blocks differs. This mostly
|
|
* indicate that the bitmap is corrupt. So exit
|
|
* without claiming the space.
|
|
*/
|
|
break;
|
|
}
|
|
ex.fe_logical = 0xDEADC0DE; /* debug value */
|
|
ext4_mb_measure_extent(ac, &ex, e4b);
|
|
|
|
i += ex.fe_len;
|
|
free -= ex.fe_len;
|
|
}
|
|
|
|
ext4_mb_check_limits(ac, e4b, 1);
|
|
}
|
|
|
|
/*
|
|
* This is a special case for storages like raid5
|
|
* we try to find stripe-aligned chunks for stripe-size-multiple requests
|
|
*/
|
|
static noinline_for_stack
|
|
void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
|
|
struct ext4_buddy *e4b)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
void *bitmap = e4b->bd_bitmap;
|
|
struct ext4_free_extent ex;
|
|
ext4_fsblk_t first_group_block;
|
|
ext4_fsblk_t a;
|
|
ext4_grpblk_t i;
|
|
int max;
|
|
|
|
BUG_ON(sbi->s_stripe == 0);
|
|
|
|
/* find first stripe-aligned block in group */
|
|
first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
|
|
|
|
a = first_group_block + sbi->s_stripe - 1;
|
|
do_div(a, sbi->s_stripe);
|
|
i = (a * sbi->s_stripe) - first_group_block;
|
|
|
|
while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
|
|
if (!mb_test_bit(i, bitmap)) {
|
|
max = mb_find_extent(e4b, i, sbi->s_stripe, &ex);
|
|
if (max >= sbi->s_stripe) {
|
|
ac->ac_found++;
|
|
ex.fe_logical = 0xDEADF00D; /* debug value */
|
|
ac->ac_b_ex = ex;
|
|
ext4_mb_use_best_found(ac, e4b);
|
|
break;
|
|
}
|
|
}
|
|
i += sbi->s_stripe;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is now called BEFORE we load the buddy bitmap.
|
|
* Returns either 1 or 0 indicating that the group is either suitable
|
|
* for the allocation or not. In addition it can also return negative
|
|
* error code when something goes wrong.
|
|
*/
|
|
static int ext4_mb_good_group(struct ext4_allocation_context *ac,
|
|
ext4_group_t group, int cr)
|
|
{
|
|
unsigned free, fragments;
|
|
int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
|
|
struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
|
|
|
|
BUG_ON(cr < 0 || cr >= 4);
|
|
|
|
free = grp->bb_free;
|
|
if (free == 0)
|
|
return 0;
|
|
if (cr <= 2 && free < ac->ac_g_ex.fe_len)
|
|
return 0;
|
|
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
|
|
return 0;
|
|
|
|
/* We only do this if the grp has never been initialized */
|
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
|
|
int ret = ext4_mb_init_group(ac->ac_sb, group, GFP_NOFS);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
fragments = grp->bb_fragments;
|
|
if (fragments == 0)
|
|
return 0;
|
|
|
|
switch (cr) {
|
|
case 0:
|
|
BUG_ON(ac->ac_2order == 0);
|
|
|
|
/* Avoid using the first bg of a flexgroup for data files */
|
|
if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
|
|
(flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
|
|
((group % flex_size) == 0))
|
|
return 0;
|
|
|
|
if ((ac->ac_2order > ac->ac_sb->s_blocksize_bits+1) ||
|
|
(free / fragments) >= ac->ac_g_ex.fe_len)
|
|
return 1;
|
|
|
|
if (grp->bb_largest_free_order < ac->ac_2order)
|
|
return 0;
|
|
|
|
return 1;
|
|
case 1:
|
|
if ((free / fragments) >= ac->ac_g_ex.fe_len)
|
|
return 1;
|
|
break;
|
|
case 2:
|
|
if (free >= ac->ac_g_ex.fe_len)
|
|
return 1;
|
|
break;
|
|
case 3:
|
|
return 1;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static noinline_for_stack int
|
|
ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
|
|
{
|
|
ext4_group_t ngroups, group, i;
|
|
int cr;
|
|
int err = 0, first_err = 0;
|
|
struct ext4_sb_info *sbi;
|
|
struct super_block *sb;
|
|
struct ext4_buddy e4b;
|
|
|
|
sb = ac->ac_sb;
|
|
sbi = EXT4_SB(sb);
|
|
ngroups = ext4_get_groups_count(sb);
|
|
/* non-extent files are limited to low blocks/groups */
|
|
if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
|
|
ngroups = sbi->s_blockfile_groups;
|
|
|
|
BUG_ON(ac->ac_status == AC_STATUS_FOUND);
|
|
|
|
/* first, try the goal */
|
|
err = ext4_mb_find_by_goal(ac, &e4b);
|
|
if (err || ac->ac_status == AC_STATUS_FOUND)
|
|
goto out;
|
|
|
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
|
|
goto out;
|
|
|
|
/*
|
|
* ac->ac2_order is set only if the fe_len is a power of 2
|
|
* if ac2_order is set we also set criteria to 0 so that we
|
|
* try exact allocation using buddy.
|
|
*/
|
|
i = fls(ac->ac_g_ex.fe_len);
|
|
ac->ac_2order = 0;
|
|
/*
|
|
* We search using buddy data only if the order of the request
|
|
* is greater than equal to the sbi_s_mb_order2_reqs
|
|
* You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
|
|
* We also support searching for power-of-two requests only for
|
|
* requests upto maximum buddy size we have constructed.
|
|
*/
|
|
if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
|
|
/*
|
|
* This should tell if fe_len is exactly power of 2
|
|
*/
|
|
if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
|
|
ac->ac_2order = array_index_nospec(i - 1,
|
|
sb->s_blocksize_bits + 2);
|
|
}
|
|
|
|
/* if stream allocation is enabled, use global goal */
|
|
if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
|
|
/* TBD: may be hot point */
|
|
spin_lock(&sbi->s_md_lock);
|
|
ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
|
|
ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
|
|
spin_unlock(&sbi->s_md_lock);
|
|
}
|
|
|
|
/* Let's just scan groups to find more-less suitable blocks */
|
|
cr = ac->ac_2order ? 0 : 1;
|
|
/*
|
|
* cr == 0 try to get exact allocation,
|
|
* cr == 3 try to get anything
|
|
*/
|
|
repeat:
|
|
for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
|
|
ac->ac_criteria = cr;
|
|
/*
|
|
* searching for the right group start
|
|
* from the goal value specified
|
|
*/
|
|
group = ac->ac_g_ex.fe_group;
|
|
|
|
for (i = 0; i < ngroups; group++, i++) {
|
|
int ret = 0;
|
|
cond_resched();
|
|
/*
|
|
* Artificially restricted ngroups for non-extent
|
|
* files makes group > ngroups possible on first loop.
|
|
*/
|
|
if (group >= ngroups)
|
|
group = 0;
|
|
|
|
/* This now checks without needing the buddy page */
|
|
ret = ext4_mb_good_group(ac, group, cr);
|
|
if (ret <= 0) {
|
|
if (!first_err)
|
|
first_err = ret;
|
|
continue;
|
|
}
|
|
|
|
err = ext4_mb_load_buddy(sb, group, &e4b);
|
|
if (err)
|
|
goto out;
|
|
|
|
ext4_lock_group(sb, group);
|
|
|
|
/*
|
|
* We need to check again after locking the
|
|
* block group
|
|
*/
|
|
ret = ext4_mb_good_group(ac, group, cr);
|
|
if (ret <= 0) {
|
|
ext4_unlock_group(sb, group);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
if (!first_err)
|
|
first_err = ret;
|
|
continue;
|
|
}
|
|
|
|
ac->ac_groups_scanned++;
|
|
if (cr == 0)
|
|
ext4_mb_simple_scan_group(ac, &e4b);
|
|
else if (cr == 1 && sbi->s_stripe &&
|
|
!(ac->ac_g_ex.fe_len % sbi->s_stripe))
|
|
ext4_mb_scan_aligned(ac, &e4b);
|
|
else
|
|
ext4_mb_complex_scan_group(ac, &e4b);
|
|
|
|
ext4_unlock_group(sb, group);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
if (ac->ac_status != AC_STATUS_CONTINUE)
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
|
|
!(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
|
|
/*
|
|
* We've been searching too long. Let's try to allocate
|
|
* the best chunk we've found so far
|
|
*/
|
|
|
|
ext4_mb_try_best_found(ac, &e4b);
|
|
if (ac->ac_status != AC_STATUS_FOUND) {
|
|
/*
|
|
* Someone more lucky has already allocated it.
|
|
* The only thing we can do is just take first
|
|
* found block(s)
|
|
printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
|
|
*/
|
|
ac->ac_b_ex.fe_group = 0;
|
|
ac->ac_b_ex.fe_start = 0;
|
|
ac->ac_b_ex.fe_len = 0;
|
|
ac->ac_status = AC_STATUS_CONTINUE;
|
|
ac->ac_flags |= EXT4_MB_HINT_FIRST;
|
|
cr = 3;
|
|
atomic_inc(&sbi->s_mb_lost_chunks);
|
|
goto repeat;
|
|
}
|
|
}
|
|
out:
|
|
if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
|
|
err = first_err;
|
|
return err;
|
|
}
|
|
|
|
static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct super_block *sb = PDE_DATA(file_inode(seq->file));
|
|
ext4_group_t group;
|
|
|
|
if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
|
|
return NULL;
|
|
group = *pos + 1;
|
|
return (void *) ((unsigned long) group);
|
|
}
|
|
|
|
static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct super_block *sb = PDE_DATA(file_inode(seq->file));
|
|
ext4_group_t group;
|
|
|
|
++*pos;
|
|
if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
|
|
return NULL;
|
|
group = *pos + 1;
|
|
return (void *) ((unsigned long) group);
|
|
}
|
|
|
|
static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct super_block *sb = PDE_DATA(file_inode(seq->file));
|
|
ext4_group_t group = (ext4_group_t) ((unsigned long) v);
|
|
int i;
|
|
int err, buddy_loaded = 0;
|
|
struct ext4_buddy e4b;
|
|
struct ext4_group_info *grinfo;
|
|
unsigned char blocksize_bits = min_t(unsigned char,
|
|
sb->s_blocksize_bits,
|
|
EXT4_MAX_BLOCK_LOG_SIZE);
|
|
struct sg {
|
|
struct ext4_group_info info;
|
|
ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
|
|
} sg;
|
|
|
|
group--;
|
|
if (group == 0)
|
|
seq_puts(seq, "#group: free frags first ["
|
|
" 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
|
|
" 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
|
|
|
|
i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
|
|
sizeof(struct ext4_group_info);
|
|
|
|
grinfo = ext4_get_group_info(sb, group);
|
|
/* Load the group info in memory only if not already loaded. */
|
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
|
|
err = ext4_mb_load_buddy(sb, group, &e4b);
|
|
if (err) {
|
|
seq_printf(seq, "#%-5u: I/O error\n", group);
|
|
return 0;
|
|
}
|
|
buddy_loaded = 1;
|
|
}
|
|
|
|
memcpy(&sg, ext4_get_group_info(sb, group), i);
|
|
|
|
if (buddy_loaded)
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
|
|
sg.info.bb_fragments, sg.info.bb_first_free);
|
|
for (i = 0; i <= 13; i++)
|
|
seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
|
|
sg.info.bb_counters[i] : 0);
|
|
seq_printf(seq, " ]\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
|
|
{
|
|
}
|
|
|
|
const struct seq_operations ext4_mb_seq_groups_ops = {
|
|
.start = ext4_mb_seq_groups_start,
|
|
.next = ext4_mb_seq_groups_next,
|
|
.stop = ext4_mb_seq_groups_stop,
|
|
.show = ext4_mb_seq_groups_show,
|
|
};
|
|
|
|
static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
|
|
{
|
|
int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
|
|
struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
|
|
|
|
BUG_ON(!cachep);
|
|
return cachep;
|
|
}
|
|
|
|
/*
|
|
* Allocate the top-level s_group_info array for the specified number
|
|
* of groups
|
|
*/
|
|
int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
unsigned size;
|
|
struct ext4_group_info ***new_groupinfo;
|
|
|
|
size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
|
|
EXT4_DESC_PER_BLOCK_BITS(sb);
|
|
if (size <= sbi->s_group_info_size)
|
|
return 0;
|
|
|
|
size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
|
|
new_groupinfo = kvzalloc(size, GFP_KERNEL);
|
|
if (!new_groupinfo) {
|
|
ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
|
|
return -ENOMEM;
|
|
}
|
|
if (sbi->s_group_info) {
|
|
memcpy(new_groupinfo, sbi->s_group_info,
|
|
sbi->s_group_info_size * sizeof(*sbi->s_group_info));
|
|
kvfree(sbi->s_group_info);
|
|
}
|
|
sbi->s_group_info = new_groupinfo;
|
|
sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
|
|
ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
|
|
sbi->s_group_info_size);
|
|
return 0;
|
|
}
|
|
|
|
/* Create and initialize ext4_group_info data for the given group. */
|
|
int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
|
|
struct ext4_group_desc *desc)
|
|
{
|
|
int i;
|
|
int metalen = 0;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct ext4_group_info **meta_group_info;
|
|
struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
|
|
|
|
/*
|
|
* First check if this group is the first of a reserved block.
|
|
* If it's true, we have to allocate a new table of pointers
|
|
* to ext4_group_info structures
|
|
*/
|
|
if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
|
|
metalen = sizeof(*meta_group_info) <<
|
|
EXT4_DESC_PER_BLOCK_BITS(sb);
|
|
meta_group_info = kmalloc(metalen, GFP_NOFS);
|
|
if (meta_group_info == NULL) {
|
|
ext4_msg(sb, KERN_ERR, "can't allocate mem "
|
|
"for a buddy group");
|
|
goto exit_meta_group_info;
|
|
}
|
|
sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
|
|
meta_group_info;
|
|
}
|
|
|
|
meta_group_info =
|
|
sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
|
|
i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
|
|
|
|
meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
|
|
if (meta_group_info[i] == NULL) {
|
|
ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
|
|
goto exit_group_info;
|
|
}
|
|
set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
|
|
&(meta_group_info[i]->bb_state));
|
|
|
|
/*
|
|
* initialize bb_free to be able to skip
|
|
* empty groups without initialization
|
|
*/
|
|
if (ext4_has_group_desc_csum(sb) &&
|
|
(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
|
|
meta_group_info[i]->bb_free =
|
|
ext4_free_clusters_after_init(sb, group, desc);
|
|
} else {
|
|
meta_group_info[i]->bb_free =
|
|
ext4_free_group_clusters(sb, desc);
|
|
}
|
|
|
|
INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
|
|
init_rwsem(&meta_group_info[i]->alloc_sem);
|
|
meta_group_info[i]->bb_free_root = RB_ROOT;
|
|
meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
|
|
|
|
#ifdef DOUBLE_CHECK
|
|
{
|
|
struct buffer_head *bh;
|
|
meta_group_info[i]->bb_bitmap =
|
|
kmalloc(sb->s_blocksize, GFP_NOFS);
|
|
BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
|
|
bh = ext4_read_block_bitmap(sb, group);
|
|
BUG_ON(IS_ERR_OR_NULL(bh));
|
|
memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
|
|
sb->s_blocksize);
|
|
put_bh(bh);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
|
|
exit_group_info:
|
|
/* If a meta_group_info table has been allocated, release it now */
|
|
if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
|
|
kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
|
|
sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] = NULL;
|
|
}
|
|
exit_meta_group_info:
|
|
return -ENOMEM;
|
|
} /* ext4_mb_add_groupinfo */
|
|
|
|
static int ext4_mb_init_backend(struct super_block *sb)
|
|
{
|
|
ext4_group_t ngroups = ext4_get_groups_count(sb);
|
|
ext4_group_t i;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
int err;
|
|
struct ext4_group_desc *desc;
|
|
struct kmem_cache *cachep;
|
|
|
|
err = ext4_mb_alloc_groupinfo(sb, ngroups);
|
|
if (err)
|
|
return err;
|
|
|
|
sbi->s_buddy_cache = new_inode(sb);
|
|
if (sbi->s_buddy_cache == NULL) {
|
|
ext4_msg(sb, KERN_ERR, "can't get new inode");
|
|
goto err_freesgi;
|
|
}
|
|
/* To avoid potentially colliding with an valid on-disk inode number,
|
|
* use EXT4_BAD_INO for the buddy cache inode number. This inode is
|
|
* not in the inode hash, so it should never be found by iget(), but
|
|
* this will avoid confusion if it ever shows up during debugging. */
|
|
sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
|
|
EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
|
|
for (i = 0; i < ngroups; i++) {
|
|
cond_resched();
|
|
desc = ext4_get_group_desc(sb, i, NULL);
|
|
if (desc == NULL) {
|
|
ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
|
|
goto err_freebuddy;
|
|
}
|
|
if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
|
|
goto err_freebuddy;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_freebuddy:
|
|
cachep = get_groupinfo_cache(sb->s_blocksize_bits);
|
|
while (i-- > 0)
|
|
kmem_cache_free(cachep, ext4_get_group_info(sb, i));
|
|
i = sbi->s_group_info_size;
|
|
while (i-- > 0)
|
|
kfree(sbi->s_group_info[i]);
|
|
iput(sbi->s_buddy_cache);
|
|
err_freesgi:
|
|
kvfree(sbi->s_group_info);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static void ext4_groupinfo_destroy_slabs(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NR_GRPINFO_CACHES; i++) {
|
|
kmem_cache_destroy(ext4_groupinfo_caches[i]);
|
|
ext4_groupinfo_caches[i] = NULL;
|
|
}
|
|
}
|
|
|
|
static int ext4_groupinfo_create_slab(size_t size)
|
|
{
|
|
static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
|
|
int slab_size;
|
|
int blocksize_bits = order_base_2(size);
|
|
int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
|
|
struct kmem_cache *cachep;
|
|
|
|
if (cache_index >= NR_GRPINFO_CACHES)
|
|
return -EINVAL;
|
|
|
|
if (unlikely(cache_index < 0))
|
|
cache_index = 0;
|
|
|
|
mutex_lock(&ext4_grpinfo_slab_create_mutex);
|
|
if (ext4_groupinfo_caches[cache_index]) {
|
|
mutex_unlock(&ext4_grpinfo_slab_create_mutex);
|
|
return 0; /* Already created */
|
|
}
|
|
|
|
slab_size = offsetof(struct ext4_group_info,
|
|
bb_counters[blocksize_bits + 2]);
|
|
|
|
cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
|
|
slab_size, 0, SLAB_RECLAIM_ACCOUNT,
|
|
NULL);
|
|
|
|
ext4_groupinfo_caches[cache_index] = cachep;
|
|
|
|
mutex_unlock(&ext4_grpinfo_slab_create_mutex);
|
|
if (!cachep) {
|
|
printk(KERN_EMERG
|
|
"EXT4-fs: no memory for groupinfo slab cache\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ext4_mb_init(struct super_block *sb)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
unsigned i, j;
|
|
unsigned offset, offset_incr;
|
|
unsigned max;
|
|
int ret;
|
|
|
|
i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
|
|
|
|
sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
|
|
if (sbi->s_mb_offsets == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
|
|
sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
|
|
if (sbi->s_mb_maxs == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = ext4_groupinfo_create_slab(sb->s_blocksize);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* order 0 is regular bitmap */
|
|
sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
|
|
sbi->s_mb_offsets[0] = 0;
|
|
|
|
i = 1;
|
|
offset = 0;
|
|
offset_incr = 1 << (sb->s_blocksize_bits - 1);
|
|
max = sb->s_blocksize << 2;
|
|
do {
|
|
sbi->s_mb_offsets[i] = offset;
|
|
sbi->s_mb_maxs[i] = max;
|
|
offset += offset_incr;
|
|
offset_incr = offset_incr >> 1;
|
|
max = max >> 1;
|
|
i++;
|
|
} while (i <= sb->s_blocksize_bits + 1);
|
|
|
|
spin_lock_init(&sbi->s_md_lock);
|
|
spin_lock_init(&sbi->s_bal_lock);
|
|
sbi->s_mb_free_pending = 0;
|
|
INIT_LIST_HEAD(&sbi->s_freed_data_list);
|
|
|
|
sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
|
|
sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
|
|
sbi->s_mb_stats = MB_DEFAULT_STATS;
|
|
sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
|
|
sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
|
|
/*
|
|
* The default group preallocation is 512, which for 4k block
|
|
* sizes translates to 2 megabytes. However for bigalloc file
|
|
* systems, this is probably too big (i.e, if the cluster size
|
|
* is 1 megabyte, then group preallocation size becomes half a
|
|
* gigabyte!). As a default, we will keep a two megabyte
|
|
* group pralloc size for cluster sizes up to 64k, and after
|
|
* that, we will force a minimum group preallocation size of
|
|
* 32 clusters. This translates to 8 megs when the cluster
|
|
* size is 256k, and 32 megs when the cluster size is 1 meg,
|
|
* which seems reasonable as a default.
|
|
*/
|
|
sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
|
|
sbi->s_cluster_bits, 32);
|
|
/*
|
|
* If there is a s_stripe > 1, then we set the s_mb_group_prealloc
|
|
* to the lowest multiple of s_stripe which is bigger than
|
|
* the s_mb_group_prealloc as determined above. We want
|
|
* the preallocation size to be an exact multiple of the
|
|
* RAID stripe size so that preallocations don't fragment
|
|
* the stripes.
|
|
*/
|
|
if (sbi->s_stripe > 1) {
|
|
sbi->s_mb_group_prealloc = roundup(
|
|
sbi->s_mb_group_prealloc, sbi->s_stripe);
|
|
}
|
|
|
|
sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
|
|
if (sbi->s_locality_groups == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
for_each_possible_cpu(i) {
|
|
struct ext4_locality_group *lg;
|
|
lg = per_cpu_ptr(sbi->s_locality_groups, i);
|
|
mutex_init(&lg->lg_mutex);
|
|
for (j = 0; j < PREALLOC_TB_SIZE; j++)
|
|
INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
|
|
spin_lock_init(&lg->lg_prealloc_lock);
|
|
}
|
|
|
|
/* init file for buddy data */
|
|
ret = ext4_mb_init_backend(sb);
|
|
if (ret != 0)
|
|
goto out_free_locality_groups;
|
|
|
|
return 0;
|
|
|
|
out_free_locality_groups:
|
|
free_percpu(sbi->s_locality_groups);
|
|
sbi->s_locality_groups = NULL;
|
|
out:
|
|
kfree(sbi->s_mb_offsets);
|
|
sbi->s_mb_offsets = NULL;
|
|
kfree(sbi->s_mb_maxs);
|
|
sbi->s_mb_maxs = NULL;
|
|
return ret;
|
|
}
|
|
|
|
/* need to called with the ext4 group lock held */
|
|
static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
|
|
{
|
|
struct ext4_prealloc_space *pa;
|
|
struct list_head *cur, *tmp;
|
|
int count = 0;
|
|
|
|
list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
|
|
pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
|
|
list_del(&pa->pa_group_list);
|
|
count++;
|
|
kmem_cache_free(ext4_pspace_cachep, pa);
|
|
}
|
|
if (count)
|
|
mb_debug(1, "mballoc: %u PAs left\n", count);
|
|
|
|
}
|
|
|
|
int ext4_mb_release(struct super_block *sb)
|
|
{
|
|
ext4_group_t ngroups = ext4_get_groups_count(sb);
|
|
ext4_group_t i;
|
|
int num_meta_group_infos;
|
|
struct ext4_group_info *grinfo;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
|
|
|
|
if (sbi->s_group_info) {
|
|
for (i = 0; i < ngroups; i++) {
|
|
cond_resched();
|
|
grinfo = ext4_get_group_info(sb, i);
|
|
#ifdef DOUBLE_CHECK
|
|
kfree(grinfo->bb_bitmap);
|
|
#endif
|
|
ext4_lock_group(sb, i);
|
|
ext4_mb_cleanup_pa(grinfo);
|
|
ext4_unlock_group(sb, i);
|
|
kmem_cache_free(cachep, grinfo);
|
|
}
|
|
num_meta_group_infos = (ngroups +
|
|
EXT4_DESC_PER_BLOCK(sb) - 1) >>
|
|
EXT4_DESC_PER_BLOCK_BITS(sb);
|
|
for (i = 0; i < num_meta_group_infos; i++)
|
|
kfree(sbi->s_group_info[i]);
|
|
kvfree(sbi->s_group_info);
|
|
}
|
|
kfree(sbi->s_mb_offsets);
|
|
kfree(sbi->s_mb_maxs);
|
|
iput(sbi->s_buddy_cache);
|
|
if (sbi->s_mb_stats) {
|
|
ext4_msg(sb, KERN_INFO,
|
|
"mballoc: %u blocks %u reqs (%u success)",
|
|
atomic_read(&sbi->s_bal_allocated),
|
|
atomic_read(&sbi->s_bal_reqs),
|
|
atomic_read(&sbi->s_bal_success));
|
|
ext4_msg(sb, KERN_INFO,
|
|
"mballoc: %u extents scanned, %u goal hits, "
|
|
"%u 2^N hits, %u breaks, %u lost",
|
|
atomic_read(&sbi->s_bal_ex_scanned),
|
|
atomic_read(&sbi->s_bal_goals),
|
|
atomic_read(&sbi->s_bal_2orders),
|
|
atomic_read(&sbi->s_bal_breaks),
|
|
atomic_read(&sbi->s_mb_lost_chunks));
|
|
ext4_msg(sb, KERN_INFO,
|
|
"mballoc: %lu generated and it took %Lu",
|
|
sbi->s_mb_buddies_generated,
|
|
sbi->s_mb_generation_time);
|
|
ext4_msg(sb, KERN_INFO,
|
|
"mballoc: %u preallocated, %u discarded",
|
|
atomic_read(&sbi->s_mb_preallocated),
|
|
atomic_read(&sbi->s_mb_discarded));
|
|
}
|
|
|
|
free_percpu(sbi->s_locality_groups);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int ext4_issue_discard(struct super_block *sb,
|
|
ext4_group_t block_group, ext4_grpblk_t cluster, int count,
|
|
struct bio **biop)
|
|
{
|
|
ext4_fsblk_t discard_block;
|
|
|
|
discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
|
|
ext4_group_first_block_no(sb, block_group));
|
|
count = EXT4_C2B(EXT4_SB(sb), count);
|
|
trace_ext4_discard_blocks(sb,
|
|
(unsigned long long) discard_block, count);
|
|
if (biop) {
|
|
return __blkdev_issue_discard(sb->s_bdev,
|
|
(sector_t)discard_block << (sb->s_blocksize_bits - 9),
|
|
(sector_t)count << (sb->s_blocksize_bits - 9),
|
|
GFP_NOFS, 0, biop);
|
|
} else
|
|
return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
|
|
}
|
|
|
|
static void ext4_free_data_in_buddy(struct super_block *sb,
|
|
struct ext4_free_data *entry)
|
|
{
|
|
struct ext4_buddy e4b;
|
|
struct ext4_group_info *db;
|
|
int err, count = 0, count2 = 0;
|
|
|
|
mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
|
|
entry->efd_count, entry->efd_group, entry);
|
|
|
|
err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
|
|
/* we expect to find existing buddy because it's pinned */
|
|
BUG_ON(err != 0);
|
|
|
|
spin_lock(&EXT4_SB(sb)->s_md_lock);
|
|
EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
|
|
spin_unlock(&EXT4_SB(sb)->s_md_lock);
|
|
|
|
db = e4b.bd_info;
|
|
/* there are blocks to put in buddy to make them really free */
|
|
count += entry->efd_count;
|
|
count2++;
|
|
ext4_lock_group(sb, entry->efd_group);
|
|
/* Take it out of per group rb tree */
|
|
rb_erase(&entry->efd_node, &(db->bb_free_root));
|
|
mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
|
|
|
|
/*
|
|
* Clear the trimmed flag for the group so that the next
|
|
* ext4_trim_fs can trim it.
|
|
* If the volume is mounted with -o discard, online discard
|
|
* is supported and the free blocks will be trimmed online.
|
|
*/
|
|
if (!test_opt(sb, DISCARD))
|
|
EXT4_MB_GRP_CLEAR_TRIMMED(db);
|
|
|
|
if (!db->bb_free_root.rb_node) {
|
|
/* No more items in the per group rb tree
|
|
* balance refcounts from ext4_mb_free_metadata()
|
|
*/
|
|
put_page(e4b.bd_buddy_page);
|
|
put_page(e4b.bd_bitmap_page);
|
|
}
|
|
ext4_unlock_group(sb, entry->efd_group);
|
|
kmem_cache_free(ext4_free_data_cachep, entry);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
mb_debug(1, "freed %u blocks in %u structures\n", count, count2);
|
|
}
|
|
|
|
/*
|
|
* This function is called by the jbd2 layer once the commit has finished,
|
|
* so we know we can free the blocks that were released with that commit.
|
|
*/
|
|
void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct ext4_free_data *entry, *tmp;
|
|
struct bio *discard_bio = NULL;
|
|
struct list_head freed_data_list;
|
|
struct list_head *cut_pos = NULL;
|
|
int err;
|
|
|
|
INIT_LIST_HEAD(&freed_data_list);
|
|
|
|
spin_lock(&sbi->s_md_lock);
|
|
list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) {
|
|
if (entry->efd_tid != commit_tid)
|
|
break;
|
|
cut_pos = &entry->efd_list;
|
|
}
|
|
if (cut_pos)
|
|
list_cut_position(&freed_data_list, &sbi->s_freed_data_list,
|
|
cut_pos);
|
|
spin_unlock(&sbi->s_md_lock);
|
|
|
|
if (test_opt(sb, DISCARD)) {
|
|
list_for_each_entry(entry, &freed_data_list, efd_list) {
|
|
err = ext4_issue_discard(sb, entry->efd_group,
|
|
entry->efd_start_cluster,
|
|
entry->efd_count,
|
|
&discard_bio);
|
|
if (err && err != -EOPNOTSUPP) {
|
|
ext4_msg(sb, KERN_WARNING, "discard request in"
|
|
" group:%d block:%d count:%d failed"
|
|
" with %d", entry->efd_group,
|
|
entry->efd_start_cluster,
|
|
entry->efd_count, err);
|
|
} else if (err == -EOPNOTSUPP)
|
|
break;
|
|
}
|
|
|
|
if (discard_bio) {
|
|
submit_bio_wait(discard_bio);
|
|
bio_put(discard_bio);
|
|
}
|
|
}
|
|
|
|
list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
|
|
ext4_free_data_in_buddy(sb, entry);
|
|
}
|
|
|
|
int __init ext4_init_mballoc(void)
|
|
{
|
|
ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
|
|
SLAB_RECLAIM_ACCOUNT);
|
|
if (ext4_pspace_cachep == NULL)
|
|
return -ENOMEM;
|
|
|
|
ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
|
|
SLAB_RECLAIM_ACCOUNT);
|
|
if (ext4_ac_cachep == NULL) {
|
|
kmem_cache_destroy(ext4_pspace_cachep);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
|
|
SLAB_RECLAIM_ACCOUNT);
|
|
if (ext4_free_data_cachep == NULL) {
|
|
kmem_cache_destroy(ext4_pspace_cachep);
|
|
kmem_cache_destroy(ext4_ac_cachep);
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void ext4_exit_mballoc(void)
|
|
{
|
|
/*
|
|
* Wait for completion of call_rcu()'s on ext4_pspace_cachep
|
|
* before destroying the slab cache.
|
|
*/
|
|
rcu_barrier();
|
|
kmem_cache_destroy(ext4_pspace_cachep);
|
|
kmem_cache_destroy(ext4_ac_cachep);
|
|
kmem_cache_destroy(ext4_free_data_cachep);
|
|
ext4_groupinfo_destroy_slabs();
|
|
}
|
|
|
|
|
|
/*
|
|
* Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
|
|
* Returns 0 if success or error code
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
|
|
handle_t *handle, unsigned int reserv_clstrs)
|
|
{
|
|
struct buffer_head *bitmap_bh = NULL;
|
|
struct ext4_group_desc *gdp;
|
|
struct buffer_head *gdp_bh;
|
|
struct ext4_sb_info *sbi;
|
|
struct super_block *sb;
|
|
ext4_fsblk_t block;
|
|
int err, len;
|
|
|
|
BUG_ON(ac->ac_status != AC_STATUS_FOUND);
|
|
BUG_ON(ac->ac_b_ex.fe_len <= 0);
|
|
|
|
sb = ac->ac_sb;
|
|
sbi = EXT4_SB(sb);
|
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
|
|
if (IS_ERR(bitmap_bh)) {
|
|
err = PTR_ERR(bitmap_bh);
|
|
bitmap_bh = NULL;
|
|
goto out_err;
|
|
}
|
|
|
|
BUFFER_TRACE(bitmap_bh, "getting write access");
|
|
err = ext4_journal_get_write_access(handle, bitmap_bh);
|
|
if (err)
|
|
goto out_err;
|
|
|
|
err = -EIO;
|
|
gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
|
|
if (!gdp)
|
|
goto out_err;
|
|
|
|
ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
|
|
ext4_free_group_clusters(sb, gdp));
|
|
|
|
BUFFER_TRACE(gdp_bh, "get_write_access");
|
|
err = ext4_journal_get_write_access(handle, gdp_bh);
|
|
if (err)
|
|
goto out_err;
|
|
|
|
block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
|
|
|
|
len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
|
|
if (!ext4_data_block_valid(sbi, block, len)) {
|
|
ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
|
|
"fs metadata", block, block+len);
|
|
/* File system mounted not to panic on error
|
|
* Fix the bitmap and return EFSCORRUPTED
|
|
* We leak some of the blocks here.
|
|
*/
|
|
ext4_lock_group(sb, ac->ac_b_ex.fe_group);
|
|
ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
|
|
ac->ac_b_ex.fe_len);
|
|
ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
|
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
|
|
if (!err)
|
|
err = -EFSCORRUPTED;
|
|
goto out_err;
|
|
}
|
|
|
|
ext4_lock_group(sb, ac->ac_b_ex.fe_group);
|
|
#ifdef AGGRESSIVE_CHECK
|
|
{
|
|
int i;
|
|
for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
|
|
BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
|
|
bitmap_bh->b_data));
|
|
}
|
|
}
|
|
#endif
|
|
ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
|
|
ac->ac_b_ex.fe_len);
|
|
if (ext4_has_group_desc_csum(sb) &&
|
|
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
|
|
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
|
|
ext4_free_group_clusters_set(sb, gdp,
|
|
ext4_free_clusters_after_init(sb,
|
|
ac->ac_b_ex.fe_group, gdp));
|
|
}
|
|
len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
|
|
ext4_free_group_clusters_set(sb, gdp, len);
|
|
ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
|
|
ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
|
|
|
|
ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
|
|
percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
|
|
/*
|
|
* Now reduce the dirty block count also. Should not go negative
|
|
*/
|
|
if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
|
|
/* release all the reserved blocks if non delalloc */
|
|
percpu_counter_sub(&sbi->s_dirtyclusters_counter,
|
|
reserv_clstrs);
|
|
|
|
if (sbi->s_log_groups_per_flex) {
|
|
ext4_group_t flex_group = ext4_flex_group(sbi,
|
|
ac->ac_b_ex.fe_group);
|
|
atomic64_sub(ac->ac_b_ex.fe_len,
|
|
&sbi->s_flex_groups[flex_group].free_clusters);
|
|
}
|
|
|
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
|
|
if (err)
|
|
goto out_err;
|
|
err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
|
|
|
|
out_err:
|
|
brelse(bitmap_bh);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* here we normalize request for locality group
|
|
* Group request are normalized to s_mb_group_prealloc, which goes to
|
|
* s_strip if we set the same via mount option.
|
|
* s_mb_group_prealloc can be configured via
|
|
* /sys/fs/ext4/<partition>/mb_group_prealloc
|
|
*
|
|
* XXX: should we try to preallocate more than the group has now?
|
|
*/
|
|
static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
struct ext4_locality_group *lg = ac->ac_lg;
|
|
|
|
BUG_ON(lg == NULL);
|
|
ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
|
|
mb_debug(1, "#%u: goal %u blocks for locality group\n",
|
|
current->pid, ac->ac_g_ex.fe_len);
|
|
}
|
|
|
|
/*
|
|
* Normalization means making request better in terms of
|
|
* size and alignment
|
|
*/
|
|
static noinline_for_stack void
|
|
ext4_mb_normalize_request(struct ext4_allocation_context *ac,
|
|
struct ext4_allocation_request *ar)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
int bsbits, max;
|
|
ext4_lblk_t end;
|
|
loff_t size, start_off;
|
|
loff_t orig_size __maybe_unused;
|
|
ext4_lblk_t start;
|
|
struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
|
|
struct ext4_prealloc_space *pa;
|
|
|
|
/* do normalize only data requests, metadata requests
|
|
do not need preallocation */
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
|
|
return;
|
|
|
|
/* sometime caller may want exact blocks */
|
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
|
|
return;
|
|
|
|
/* caller may indicate that preallocation isn't
|
|
* required (it's a tail, for example) */
|
|
if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
|
|
return;
|
|
|
|
if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
|
|
ext4_mb_normalize_group_request(ac);
|
|
return ;
|
|
}
|
|
|
|
bsbits = ac->ac_sb->s_blocksize_bits;
|
|
|
|
/* first, let's learn actual file size
|
|
* given current request is allocated */
|
|
size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
|
|
size = size << bsbits;
|
|
if (size < i_size_read(ac->ac_inode))
|
|
size = i_size_read(ac->ac_inode);
|
|
orig_size = size;
|
|
|
|
/* max size of free chunks */
|
|
max = 2 << bsbits;
|
|
|
|
#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
|
|
(req <= (size) || max <= (chunk_size))
|
|
|
|
/* first, try to predict filesize */
|
|
/* XXX: should this table be tunable? */
|
|
start_off = 0;
|
|
if (size <= 16 * 1024) {
|
|
size = 16 * 1024;
|
|
} else if (size <= 32 * 1024) {
|
|
size = 32 * 1024;
|
|
} else if (size <= 64 * 1024) {
|
|
size = 64 * 1024;
|
|
} else if (size <= 128 * 1024) {
|
|
size = 128 * 1024;
|
|
} else if (size <= 256 * 1024) {
|
|
size = 256 * 1024;
|
|
} else if (size <= 512 * 1024) {
|
|
size = 512 * 1024;
|
|
} else if (size <= 1024 * 1024) {
|
|
size = 1024 * 1024;
|
|
} else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
|
|
start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
|
|
(21 - bsbits)) << 21;
|
|
size = 2 * 1024 * 1024;
|
|
} else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
|
|
start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
|
|
(22 - bsbits)) << 22;
|
|
size = 4 * 1024 * 1024;
|
|
} else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
|
|
(8<<20)>>bsbits, max, 8 * 1024)) {
|
|
start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
|
|
(23 - bsbits)) << 23;
|
|
size = 8 * 1024 * 1024;
|
|
} else {
|
|
start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
|
|
size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
|
|
ac->ac_o_ex.fe_len) << bsbits;
|
|
}
|
|
size = size >> bsbits;
|
|
start = start_off >> bsbits;
|
|
|
|
/* don't cover already allocated blocks in selected range */
|
|
if (ar->pleft && start <= ar->lleft) {
|
|
size -= ar->lleft + 1 - start;
|
|
start = ar->lleft + 1;
|
|
}
|
|
if (ar->pright && start + size - 1 >= ar->lright)
|
|
size -= start + size - ar->lright;
|
|
|
|
/*
|
|
* Trim allocation request for filesystems with artificially small
|
|
* groups.
|
|
*/
|
|
if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
|
|
size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
|
|
|
|
end = start + size;
|
|
|
|
/* check we don't cross already preallocated blocks */
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
|
|
ext4_lblk_t pa_end;
|
|
|
|
if (pa->pa_deleted)
|
|
continue;
|
|
spin_lock(&pa->pa_lock);
|
|
if (pa->pa_deleted) {
|
|
spin_unlock(&pa->pa_lock);
|
|
continue;
|
|
}
|
|
|
|
pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
|
|
pa->pa_len);
|
|
|
|
/* PA must not overlap original request */
|
|
BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
|
|
ac->ac_o_ex.fe_logical < pa->pa_lstart));
|
|
|
|
/* skip PAs this normalized request doesn't overlap with */
|
|
if (pa->pa_lstart >= end || pa_end <= start) {
|
|
spin_unlock(&pa->pa_lock);
|
|
continue;
|
|
}
|
|
BUG_ON(pa->pa_lstart <= start && pa_end >= end);
|
|
|
|
/* adjust start or end to be adjacent to this pa */
|
|
if (pa_end <= ac->ac_o_ex.fe_logical) {
|
|
BUG_ON(pa_end < start);
|
|
start = pa_end;
|
|
} else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
|
|
BUG_ON(pa->pa_lstart > end);
|
|
end = pa->pa_lstart;
|
|
}
|
|
spin_unlock(&pa->pa_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
size = end - start;
|
|
|
|
/* XXX: extra loop to check we really don't overlap preallocations */
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
|
|
ext4_lblk_t pa_end;
|
|
|
|
spin_lock(&pa->pa_lock);
|
|
if (pa->pa_deleted == 0) {
|
|
pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
|
|
pa->pa_len);
|
|
BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
|
|
}
|
|
spin_unlock(&pa->pa_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (start + size <= ac->ac_o_ex.fe_logical &&
|
|
start > ac->ac_o_ex.fe_logical) {
|
|
ext4_msg(ac->ac_sb, KERN_ERR,
|
|
"start %lu, size %lu, fe_logical %lu",
|
|
(unsigned long) start, (unsigned long) size,
|
|
(unsigned long) ac->ac_o_ex.fe_logical);
|
|
BUG();
|
|
}
|
|
BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
|
|
|
|
/* now prepare goal request */
|
|
|
|
/* XXX: is it better to align blocks WRT to logical
|
|
* placement or satisfy big request as is */
|
|
ac->ac_g_ex.fe_logical = start;
|
|
ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
|
|
|
|
/* define goal start in order to merge */
|
|
if (ar->pright && (ar->lright == (start + size))) {
|
|
/* merge to the right */
|
|
ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
|
|
&ac->ac_f_ex.fe_group,
|
|
&ac->ac_f_ex.fe_start);
|
|
ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
|
|
}
|
|
if (ar->pleft && (ar->lleft + 1 == start)) {
|
|
/* merge to the left */
|
|
ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
|
|
&ac->ac_f_ex.fe_group,
|
|
&ac->ac_f_ex.fe_start);
|
|
ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
|
|
}
|
|
|
|
mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size,
|
|
(unsigned) orig_size, (unsigned) start);
|
|
}
|
|
|
|
static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
|
|
if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
|
|
atomic_inc(&sbi->s_bal_reqs);
|
|
atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
|
|
if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
|
|
atomic_inc(&sbi->s_bal_success);
|
|
atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
|
|
if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
|
|
ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
|
|
atomic_inc(&sbi->s_bal_goals);
|
|
if (ac->ac_found > sbi->s_mb_max_to_scan)
|
|
atomic_inc(&sbi->s_bal_breaks);
|
|
}
|
|
|
|
if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
|
|
trace_ext4_mballoc_alloc(ac);
|
|
else
|
|
trace_ext4_mballoc_prealloc(ac);
|
|
}
|
|
|
|
/*
|
|
* Called on failure; free up any blocks from the inode PA for this
|
|
* context. We don't need this for MB_GROUP_PA because we only change
|
|
* pa_free in ext4_mb_release_context(), but on failure, we've already
|
|
* zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
|
|
*/
|
|
static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
|
|
{
|
|
struct ext4_prealloc_space *pa = ac->ac_pa;
|
|
struct ext4_buddy e4b;
|
|
int err;
|
|
|
|
if (pa == NULL) {
|
|
if (ac->ac_f_ex.fe_len == 0)
|
|
return;
|
|
err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
|
|
if (err) {
|
|
/*
|
|
* This should never happen since we pin the
|
|
* pages in the ext4_allocation_context so
|
|
* ext4_mb_load_buddy() should never fail.
|
|
*/
|
|
WARN(1, "mb_load_buddy failed (%d)", err);
|
|
return;
|
|
}
|
|
ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
|
|
mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
|
|
ac->ac_f_ex.fe_len);
|
|
ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
return;
|
|
}
|
|
if (pa->pa_type == MB_INODE_PA)
|
|
pa->pa_free += ac->ac_b_ex.fe_len;
|
|
}
|
|
|
|
/*
|
|
* use blocks preallocated to inode
|
|
*/
|
|
static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
|
|
struct ext4_prealloc_space *pa)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
ext4_fsblk_t start;
|
|
ext4_fsblk_t end;
|
|
int len;
|
|
|
|
/* found preallocated blocks, use them */
|
|
start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
|
|
end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
|
|
start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
|
|
len = EXT4_NUM_B2C(sbi, end - start);
|
|
ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
|
|
&ac->ac_b_ex.fe_start);
|
|
ac->ac_b_ex.fe_len = len;
|
|
ac->ac_status = AC_STATUS_FOUND;
|
|
ac->ac_pa = pa;
|
|
|
|
BUG_ON(start < pa->pa_pstart);
|
|
BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
|
|
BUG_ON(pa->pa_free < len);
|
|
pa->pa_free -= len;
|
|
|
|
mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa);
|
|
}
|
|
|
|
/*
|
|
* use blocks preallocated to locality group
|
|
*/
|
|
static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
|
|
struct ext4_prealloc_space *pa)
|
|
{
|
|
unsigned int len = ac->ac_o_ex.fe_len;
|
|
|
|
ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
|
|
&ac->ac_b_ex.fe_group,
|
|
&ac->ac_b_ex.fe_start);
|
|
ac->ac_b_ex.fe_len = len;
|
|
ac->ac_status = AC_STATUS_FOUND;
|
|
ac->ac_pa = pa;
|
|
|
|
/* we don't correct pa_pstart or pa_plen here to avoid
|
|
* possible race when the group is being loaded concurrently
|
|
* instead we correct pa later, after blocks are marked
|
|
* in on-disk bitmap -- see ext4_mb_release_context()
|
|
* Other CPUs are prevented from allocating from this pa by lg_mutex
|
|
*/
|
|
mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
|
|
}
|
|
|
|
/*
|
|
* Return the prealloc space that have minimal distance
|
|
* from the goal block. @cpa is the prealloc
|
|
* space that is having currently known minimal distance
|
|
* from the goal block.
|
|
*/
|
|
static struct ext4_prealloc_space *
|
|
ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
|
|
struct ext4_prealloc_space *pa,
|
|
struct ext4_prealloc_space *cpa)
|
|
{
|
|
ext4_fsblk_t cur_distance, new_distance;
|
|
|
|
if (cpa == NULL) {
|
|
atomic_inc(&pa->pa_count);
|
|
return pa;
|
|
}
|
|
cur_distance = abs(goal_block - cpa->pa_pstart);
|
|
new_distance = abs(goal_block - pa->pa_pstart);
|
|
|
|
if (cur_distance <= new_distance)
|
|
return cpa;
|
|
|
|
/* drop the previous reference */
|
|
atomic_dec(&cpa->pa_count);
|
|
atomic_inc(&pa->pa_count);
|
|
return pa;
|
|
}
|
|
|
|
/*
|
|
* search goal blocks in preallocated space
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
int order, i;
|
|
struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
|
|
struct ext4_locality_group *lg;
|
|
struct ext4_prealloc_space *pa, *cpa = NULL;
|
|
ext4_fsblk_t goal_block;
|
|
|
|
/* only data can be preallocated */
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
|
|
return 0;
|
|
|
|
/* first, try per-file preallocation */
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
|
|
|
|
/* all fields in this condition don't change,
|
|
* so we can skip locking for them */
|
|
if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
|
|
ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
|
|
EXT4_C2B(sbi, pa->pa_len)))
|
|
continue;
|
|
|
|
/* non-extent files can't have physical blocks past 2^32 */
|
|
if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
|
|
(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >
|
|
EXT4_MAX_BLOCK_FILE_PHYS))
|
|
continue;
|
|
|
|
/* found preallocated blocks, use them */
|
|
spin_lock(&pa->pa_lock);
|
|
if (pa->pa_deleted == 0 && pa->pa_free) {
|
|
atomic_inc(&pa->pa_count);
|
|
ext4_mb_use_inode_pa(ac, pa);
|
|
spin_unlock(&pa->pa_lock);
|
|
ac->ac_criteria = 10;
|
|
rcu_read_unlock();
|
|
return 1;
|
|
}
|
|
spin_unlock(&pa->pa_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
/* can we use group allocation? */
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
|
|
return 0;
|
|
|
|
/* inode may have no locality group for some reason */
|
|
lg = ac->ac_lg;
|
|
if (lg == NULL)
|
|
return 0;
|
|
order = fls(ac->ac_o_ex.fe_len) - 1;
|
|
if (order > PREALLOC_TB_SIZE - 1)
|
|
/* The max size of hash table is PREALLOC_TB_SIZE */
|
|
order = PREALLOC_TB_SIZE - 1;
|
|
|
|
goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
|
|
/*
|
|
* search for the prealloc space that is having
|
|
* minimal distance from the goal block.
|
|
*/
|
|
for (i = order; i < PREALLOC_TB_SIZE; i++) {
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
|
|
pa_inode_list) {
|
|
spin_lock(&pa->pa_lock);
|
|
if (pa->pa_deleted == 0 &&
|
|
pa->pa_free >= ac->ac_o_ex.fe_len) {
|
|
|
|
cpa = ext4_mb_check_group_pa(goal_block,
|
|
pa, cpa);
|
|
}
|
|
spin_unlock(&pa->pa_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
if (cpa) {
|
|
ext4_mb_use_group_pa(ac, cpa);
|
|
ac->ac_criteria = 20;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* the function goes through all block freed in the group
|
|
* but not yet committed and marks them used in in-core bitmap.
|
|
* buddy must be generated from this bitmap
|
|
* Need to be called with the ext4 group lock held
|
|
*/
|
|
static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
|
|
ext4_group_t group)
|
|
{
|
|
struct rb_node *n;
|
|
struct ext4_group_info *grp;
|
|
struct ext4_free_data *entry;
|
|
|
|
grp = ext4_get_group_info(sb, group);
|
|
n = rb_first(&(grp->bb_free_root));
|
|
|
|
while (n) {
|
|
entry = rb_entry(n, struct ext4_free_data, efd_node);
|
|
ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
|
|
n = rb_next(n);
|
|
}
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* the function goes through all preallocation in this group and marks them
|
|
* used in in-core bitmap. buddy must be generated from this bitmap
|
|
* Need to be called with ext4 group lock held
|
|
*/
|
|
static noinline_for_stack
|
|
void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
|
|
ext4_group_t group)
|
|
{
|
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
|
|
struct ext4_prealloc_space *pa;
|
|
struct list_head *cur;
|
|
ext4_group_t groupnr;
|
|
ext4_grpblk_t start;
|
|
int preallocated = 0;
|
|
int len;
|
|
|
|
/* all form of preallocation discards first load group,
|
|
* so the only competing code is preallocation use.
|
|
* we don't need any locking here
|
|
* notice we do NOT ignore preallocations with pa_deleted
|
|
* otherwise we could leave used blocks available for
|
|
* allocation in buddy when concurrent ext4_mb_put_pa()
|
|
* is dropping preallocation
|
|
*/
|
|
list_for_each(cur, &grp->bb_prealloc_list) {
|
|
pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
|
|
spin_lock(&pa->pa_lock);
|
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart,
|
|
&groupnr, &start);
|
|
len = pa->pa_len;
|
|
spin_unlock(&pa->pa_lock);
|
|
if (unlikely(len == 0))
|
|
continue;
|
|
BUG_ON(groupnr != group);
|
|
ext4_set_bits(bitmap, start, len);
|
|
preallocated += len;
|
|
}
|
|
mb_debug(1, "preallocated %u for group %u\n", preallocated, group);
|
|
}
|
|
|
|
static void ext4_mb_pa_callback(struct rcu_head *head)
|
|
{
|
|
struct ext4_prealloc_space *pa;
|
|
pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
|
|
|
|
BUG_ON(atomic_read(&pa->pa_count));
|
|
BUG_ON(pa->pa_deleted == 0);
|
|
kmem_cache_free(ext4_pspace_cachep, pa);
|
|
}
|
|
|
|
/*
|
|
* drops a reference to preallocated space descriptor
|
|
* if this was the last reference and the space is consumed
|
|
*/
|
|
static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
|
|
struct super_block *sb, struct ext4_prealloc_space *pa)
|
|
{
|
|
ext4_group_t grp;
|
|
ext4_fsblk_t grp_blk;
|
|
|
|
/* in this short window concurrent discard can set pa_deleted */
|
|
spin_lock(&pa->pa_lock);
|
|
if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
|
|
spin_unlock(&pa->pa_lock);
|
|
return;
|
|
}
|
|
|
|
if (pa->pa_deleted == 1) {
|
|
spin_unlock(&pa->pa_lock);
|
|
return;
|
|
}
|
|
|
|
pa->pa_deleted = 1;
|
|
spin_unlock(&pa->pa_lock);
|
|
|
|
grp_blk = pa->pa_pstart;
|
|
/*
|
|
* If doing group-based preallocation, pa_pstart may be in the
|
|
* next group when pa is used up
|
|
*/
|
|
if (pa->pa_type == MB_GROUP_PA)
|
|
grp_blk--;
|
|
|
|
grp = ext4_get_group_number(sb, grp_blk);
|
|
|
|
/*
|
|
* possible race:
|
|
*
|
|
* P1 (buddy init) P2 (regular allocation)
|
|
* find block B in PA
|
|
* copy on-disk bitmap to buddy
|
|
* mark B in on-disk bitmap
|
|
* drop PA from group
|
|
* mark all PAs in buddy
|
|
*
|
|
* thus, P1 initializes buddy with B available. to prevent this
|
|
* we make "copy" and "mark all PAs" atomic and serialize "drop PA"
|
|
* against that pair
|
|
*/
|
|
ext4_lock_group(sb, grp);
|
|
list_del(&pa->pa_group_list);
|
|
ext4_unlock_group(sb, grp);
|
|
|
|
spin_lock(pa->pa_obj_lock);
|
|
list_del_rcu(&pa->pa_inode_list);
|
|
spin_unlock(pa->pa_obj_lock);
|
|
|
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
|
|
}
|
|
|
|
/*
|
|
* creates new preallocated space for given inode
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct ext4_prealloc_space *pa;
|
|
struct ext4_group_info *grp;
|
|
struct ext4_inode_info *ei;
|
|
|
|
/* preallocate only when found space is larger then requested */
|
|
BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
|
|
BUG_ON(ac->ac_status != AC_STATUS_FOUND);
|
|
BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
|
|
|
|
pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
|
|
if (pa == NULL)
|
|
return -ENOMEM;
|
|
|
|
if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
|
|
int winl;
|
|
int wins;
|
|
int win;
|
|
int offs;
|
|
|
|
/* we can't allocate as much as normalizer wants.
|
|
* so, found space must get proper lstart
|
|
* to cover original request */
|
|
BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
|
|
BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
|
|
|
|
/* we're limited by original request in that
|
|
* logical block must be covered any way
|
|
* winl is window we can move our chunk within */
|
|
winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
|
|
|
|
/* also, we should cover whole original request */
|
|
wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len);
|
|
|
|
/* the smallest one defines real window */
|
|
win = min(winl, wins);
|
|
|
|
offs = ac->ac_o_ex.fe_logical %
|
|
EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
|
|
if (offs && offs < win)
|
|
win = offs;
|
|
|
|
ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical -
|
|
EXT4_NUM_B2C(sbi, win);
|
|
BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
|
|
BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
|
|
}
|
|
|
|
/* preallocation can change ac_b_ex, thus we store actually
|
|
* allocated blocks for history */
|
|
ac->ac_f_ex = ac->ac_b_ex;
|
|
|
|
pa->pa_lstart = ac->ac_b_ex.fe_logical;
|
|
pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
|
|
pa->pa_len = ac->ac_b_ex.fe_len;
|
|
pa->pa_free = pa->pa_len;
|
|
atomic_set(&pa->pa_count, 1);
|
|
spin_lock_init(&pa->pa_lock);
|
|
INIT_LIST_HEAD(&pa->pa_inode_list);
|
|
INIT_LIST_HEAD(&pa->pa_group_list);
|
|
pa->pa_deleted = 0;
|
|
pa->pa_type = MB_INODE_PA;
|
|
|
|
mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa,
|
|
pa->pa_pstart, pa->pa_len, pa->pa_lstart);
|
|
trace_ext4_mb_new_inode_pa(ac, pa);
|
|
|
|
ext4_mb_use_inode_pa(ac, pa);
|
|
atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
|
|
|
|
ei = EXT4_I(ac->ac_inode);
|
|
grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
|
|
|
|
pa->pa_obj_lock = &ei->i_prealloc_lock;
|
|
pa->pa_inode = ac->ac_inode;
|
|
|
|
ext4_lock_group(sb, ac->ac_b_ex.fe_group);
|
|
list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
|
|
ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
|
|
|
|
spin_lock(pa->pa_obj_lock);
|
|
list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
|
|
spin_unlock(pa->pa_obj_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* creates new preallocated space for locality group inodes belongs to
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
struct ext4_locality_group *lg;
|
|
struct ext4_prealloc_space *pa;
|
|
struct ext4_group_info *grp;
|
|
|
|
/* preallocate only when found space is larger then requested */
|
|
BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
|
|
BUG_ON(ac->ac_status != AC_STATUS_FOUND);
|
|
BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
|
|
|
|
BUG_ON(ext4_pspace_cachep == NULL);
|
|
pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
|
|
if (pa == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* preallocation can change ac_b_ex, thus we store actually
|
|
* allocated blocks for history */
|
|
ac->ac_f_ex = ac->ac_b_ex;
|
|
|
|
pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
|
|
pa->pa_lstart = pa->pa_pstart;
|
|
pa->pa_len = ac->ac_b_ex.fe_len;
|
|
pa->pa_free = pa->pa_len;
|
|
atomic_set(&pa->pa_count, 1);
|
|
spin_lock_init(&pa->pa_lock);
|
|
INIT_LIST_HEAD(&pa->pa_inode_list);
|
|
INIT_LIST_HEAD(&pa->pa_group_list);
|
|
pa->pa_deleted = 0;
|
|
pa->pa_type = MB_GROUP_PA;
|
|
|
|
mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa,
|
|
pa->pa_pstart, pa->pa_len, pa->pa_lstart);
|
|
trace_ext4_mb_new_group_pa(ac, pa);
|
|
|
|
ext4_mb_use_group_pa(ac, pa);
|
|
atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
|
|
|
|
grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
|
|
lg = ac->ac_lg;
|
|
BUG_ON(lg == NULL);
|
|
|
|
pa->pa_obj_lock = &lg->lg_prealloc_lock;
|
|
pa->pa_inode = NULL;
|
|
|
|
ext4_lock_group(sb, ac->ac_b_ex.fe_group);
|
|
list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
|
|
ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
|
|
|
|
/*
|
|
* We will later add the new pa to the right bucket
|
|
* after updating the pa_free in ext4_mb_release_context
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
|
|
{
|
|
int err;
|
|
|
|
if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
|
|
err = ext4_mb_new_group_pa(ac);
|
|
else
|
|
err = ext4_mb_new_inode_pa(ac);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* finds all unused blocks in on-disk bitmap, frees them in
|
|
* in-core bitmap and buddy.
|
|
* @pa must be unlinked from inode and group lists, so that
|
|
* nobody else can find/use it.
|
|
* the caller MUST hold group/inode locks.
|
|
* TODO: optimize the case when there are no in-core structures yet
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
|
|
struct ext4_prealloc_space *pa)
|
|
{
|
|
struct super_block *sb = e4b->bd_sb;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
unsigned int end;
|
|
unsigned int next;
|
|
ext4_group_t group;
|
|
ext4_grpblk_t bit;
|
|
unsigned long long grp_blk_start;
|
|
int free = 0;
|
|
|
|
BUG_ON(pa->pa_deleted == 0);
|
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
|
|
grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
|
|
BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
|
|
end = bit + pa->pa_len;
|
|
|
|
while (bit < end) {
|
|
bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
|
|
if (bit >= end)
|
|
break;
|
|
next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
|
|
mb_debug(1, " free preallocated %u/%u in group %u\n",
|
|
(unsigned) ext4_group_first_block_no(sb, group) + bit,
|
|
(unsigned) next - bit, (unsigned) group);
|
|
free += next - bit;
|
|
|
|
trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
|
|
trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
|
|
EXT4_C2B(sbi, bit)),
|
|
next - bit);
|
|
mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
|
|
bit = next + 1;
|
|
}
|
|
if (free != pa->pa_free) {
|
|
ext4_msg(e4b->bd_sb, KERN_CRIT,
|
|
"pa %p: logic %lu, phys. %lu, len %lu",
|
|
pa, (unsigned long) pa->pa_lstart,
|
|
(unsigned long) pa->pa_pstart,
|
|
(unsigned long) pa->pa_len);
|
|
ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
|
|
free, pa->pa_free);
|
|
/*
|
|
* pa is already deleted so we use the value obtained
|
|
* from the bitmap and continue.
|
|
*/
|
|
}
|
|
atomic_add(free, &sbi->s_mb_discarded);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static noinline_for_stack int
|
|
ext4_mb_release_group_pa(struct ext4_buddy *e4b,
|
|
struct ext4_prealloc_space *pa)
|
|
{
|
|
struct super_block *sb = e4b->bd_sb;
|
|
ext4_group_t group;
|
|
ext4_grpblk_t bit;
|
|
|
|
trace_ext4_mb_release_group_pa(sb, pa);
|
|
BUG_ON(pa->pa_deleted == 0);
|
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
|
|
BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
|
|
mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
|
|
atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
|
|
trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* releases all preallocations in given group
|
|
*
|
|
* first, we need to decide discard policy:
|
|
* - when do we discard
|
|
* 1) ENOSPC
|
|
* - how many do we discard
|
|
* 1) how many requested
|
|
*/
|
|
static noinline_for_stack int
|
|
ext4_mb_discard_group_preallocations(struct super_block *sb,
|
|
ext4_group_t group, int needed)
|
|
{
|
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
|
|
struct buffer_head *bitmap_bh = NULL;
|
|
struct ext4_prealloc_space *pa, *tmp;
|
|
struct list_head list;
|
|
struct ext4_buddy e4b;
|
|
int err;
|
|
int busy = 0;
|
|
int free = 0;
|
|
|
|
mb_debug(1, "discard preallocation for group %u\n", group);
|
|
|
|
if (list_empty(&grp->bb_prealloc_list))
|
|
return 0;
|
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, group);
|
|
if (IS_ERR(bitmap_bh)) {
|
|
err = PTR_ERR(bitmap_bh);
|
|
ext4_error(sb, "Error %d reading block bitmap for %u",
|
|
err, group);
|
|
return 0;
|
|
}
|
|
|
|
err = ext4_mb_load_buddy(sb, group, &e4b);
|
|
if (err) {
|
|
ext4_warning(sb, "Error %d loading buddy information for %u",
|
|
err, group);
|
|
put_bh(bitmap_bh);
|
|
return 0;
|
|
}
|
|
|
|
if (needed == 0)
|
|
needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
|
|
|
|
INIT_LIST_HEAD(&list);
|
|
repeat:
|
|
ext4_lock_group(sb, group);
|
|
list_for_each_entry_safe(pa, tmp,
|
|
&grp->bb_prealloc_list, pa_group_list) {
|
|
spin_lock(&pa->pa_lock);
|
|
if (atomic_read(&pa->pa_count)) {
|
|
spin_unlock(&pa->pa_lock);
|
|
busy = 1;
|
|
continue;
|
|
}
|
|
if (pa->pa_deleted) {
|
|
spin_unlock(&pa->pa_lock);
|
|
continue;
|
|
}
|
|
|
|
/* seems this one can be freed ... */
|
|
pa->pa_deleted = 1;
|
|
|
|
/* we can trust pa_free ... */
|
|
free += pa->pa_free;
|
|
|
|
spin_unlock(&pa->pa_lock);
|
|
|
|
list_del(&pa->pa_group_list);
|
|
list_add(&pa->u.pa_tmp_list, &list);
|
|
}
|
|
|
|
/* if we still need more blocks and some PAs were used, try again */
|
|
if (free < needed && busy) {
|
|
busy = 0;
|
|
ext4_unlock_group(sb, group);
|
|
cond_resched();
|
|
goto repeat;
|
|
}
|
|
|
|
/* found anything to free? */
|
|
if (list_empty(&list)) {
|
|
BUG_ON(free != 0);
|
|
goto out;
|
|
}
|
|
|
|
/* now free all selected PAs */
|
|
list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
|
|
|
|
/* remove from object (inode or locality group) */
|
|
spin_lock(pa->pa_obj_lock);
|
|
list_del_rcu(&pa->pa_inode_list);
|
|
spin_unlock(pa->pa_obj_lock);
|
|
|
|
if (pa->pa_type == MB_GROUP_PA)
|
|
ext4_mb_release_group_pa(&e4b, pa);
|
|
else
|
|
ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
|
|
|
|
list_del(&pa->u.pa_tmp_list);
|
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
|
|
}
|
|
|
|
out:
|
|
ext4_unlock_group(sb, group);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
put_bh(bitmap_bh);
|
|
return free;
|
|
}
|
|
|
|
/*
|
|
* releases all non-used preallocated blocks for given inode
|
|
*
|
|
* It's important to discard preallocations under i_data_sem
|
|
* We don't want another block to be served from the prealloc
|
|
* space when we are discarding the inode prealloc space.
|
|
*
|
|
* FIXME!! Make sure it is valid at all the call sites
|
|
*/
|
|
void ext4_discard_preallocations(struct inode *inode)
|
|
{
|
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
struct super_block *sb = inode->i_sb;
|
|
struct buffer_head *bitmap_bh = NULL;
|
|
struct ext4_prealloc_space *pa, *tmp;
|
|
ext4_group_t group = 0;
|
|
struct list_head list;
|
|
struct ext4_buddy e4b;
|
|
int err;
|
|
|
|
if (!S_ISREG(inode->i_mode)) {
|
|
/*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
|
|
return;
|
|
}
|
|
|
|
mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino);
|
|
trace_ext4_discard_preallocations(inode);
|
|
|
|
INIT_LIST_HEAD(&list);
|
|
|
|
repeat:
|
|
/* first, collect all pa's in the inode */
|
|
spin_lock(&ei->i_prealloc_lock);
|
|
while (!list_empty(&ei->i_prealloc_list)) {
|
|
pa = list_entry(ei->i_prealloc_list.next,
|
|
struct ext4_prealloc_space, pa_inode_list);
|
|
BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
|
|
spin_lock(&pa->pa_lock);
|
|
if (atomic_read(&pa->pa_count)) {
|
|
/* this shouldn't happen often - nobody should
|
|
* use preallocation while we're discarding it */
|
|
spin_unlock(&pa->pa_lock);
|
|
spin_unlock(&ei->i_prealloc_lock);
|
|
ext4_msg(sb, KERN_ERR,
|
|
"uh-oh! used pa while discarding");
|
|
WARN_ON(1);
|
|
schedule_timeout_uninterruptible(HZ);
|
|
goto repeat;
|
|
|
|
}
|
|
if (pa->pa_deleted == 0) {
|
|
pa->pa_deleted = 1;
|
|
spin_unlock(&pa->pa_lock);
|
|
list_del_rcu(&pa->pa_inode_list);
|
|
list_add(&pa->u.pa_tmp_list, &list);
|
|
continue;
|
|
}
|
|
|
|
/* someone is deleting pa right now */
|
|
spin_unlock(&pa->pa_lock);
|
|
spin_unlock(&ei->i_prealloc_lock);
|
|
|
|
/* we have to wait here because pa_deleted
|
|
* doesn't mean pa is already unlinked from
|
|
* the list. as we might be called from
|
|
* ->clear_inode() the inode will get freed
|
|
* and concurrent thread which is unlinking
|
|
* pa from inode's list may access already
|
|
* freed memory, bad-bad-bad */
|
|
|
|
/* XXX: if this happens too often, we can
|
|
* add a flag to force wait only in case
|
|
* of ->clear_inode(), but not in case of
|
|
* regular truncate */
|
|
schedule_timeout_uninterruptible(HZ);
|
|
goto repeat;
|
|
}
|
|
spin_unlock(&ei->i_prealloc_lock);
|
|
|
|
list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
|
|
BUG_ON(pa->pa_type != MB_INODE_PA);
|
|
group = ext4_get_group_number(sb, pa->pa_pstart);
|
|
|
|
err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
|
|
GFP_NOFS|__GFP_NOFAIL);
|
|
if (err) {
|
|
ext4_error(sb, "Error %d loading buddy information for %u",
|
|
err, group);
|
|
continue;
|
|
}
|
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, group);
|
|
if (IS_ERR(bitmap_bh)) {
|
|
err = PTR_ERR(bitmap_bh);
|
|
ext4_error(sb, "Error %d reading block bitmap for %u",
|
|
err, group);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
continue;
|
|
}
|
|
|
|
ext4_lock_group(sb, group);
|
|
list_del(&pa->pa_group_list);
|
|
ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
|
|
ext4_unlock_group(sb, group);
|
|
|
|
ext4_mb_unload_buddy(&e4b);
|
|
put_bh(bitmap_bh);
|
|
|
|
list_del(&pa->u.pa_tmp_list);
|
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_EXT4_DEBUG
|
|
static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
|
|
{
|
|
struct super_block *sb = ac->ac_sb;
|
|
ext4_group_t ngroups, i;
|
|
|
|
if (!ext4_mballoc_debug ||
|
|
(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED))
|
|
return;
|
|
|
|
ext4_msg(ac->ac_sb, KERN_ERR, "Can't allocate:"
|
|
" Allocation context details:");
|
|
ext4_msg(ac->ac_sb, KERN_ERR, "status %d flags %d",
|
|
ac->ac_status, ac->ac_flags);
|
|
ext4_msg(ac->ac_sb, KERN_ERR, "orig %lu/%lu/%lu@%lu, "
|
|
"goal %lu/%lu/%lu@%lu, "
|
|
"best %lu/%lu/%lu@%lu cr %d",
|
|
(unsigned long)ac->ac_o_ex.fe_group,
|
|
(unsigned long)ac->ac_o_ex.fe_start,
|
|
(unsigned long)ac->ac_o_ex.fe_len,
|
|
(unsigned long)ac->ac_o_ex.fe_logical,
|
|
(unsigned long)ac->ac_g_ex.fe_group,
|
|
(unsigned long)ac->ac_g_ex.fe_start,
|
|
(unsigned long)ac->ac_g_ex.fe_len,
|
|
(unsigned long)ac->ac_g_ex.fe_logical,
|
|
(unsigned long)ac->ac_b_ex.fe_group,
|
|
(unsigned long)ac->ac_b_ex.fe_start,
|
|
(unsigned long)ac->ac_b_ex.fe_len,
|
|
(unsigned long)ac->ac_b_ex.fe_logical,
|
|
(int)ac->ac_criteria);
|
|
ext4_msg(ac->ac_sb, KERN_ERR, "%d found", ac->ac_found);
|
|
ext4_msg(ac->ac_sb, KERN_ERR, "groups: ");
|
|
ngroups = ext4_get_groups_count(sb);
|
|
for (i = 0; i < ngroups; i++) {
|
|
struct ext4_group_info *grp = ext4_get_group_info(sb, i);
|
|
struct ext4_prealloc_space *pa;
|
|
ext4_grpblk_t start;
|
|
struct list_head *cur;
|
|
ext4_lock_group(sb, i);
|
|
list_for_each(cur, &grp->bb_prealloc_list) {
|
|
pa = list_entry(cur, struct ext4_prealloc_space,
|
|
pa_group_list);
|
|
spin_lock(&pa->pa_lock);
|
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart,
|
|
NULL, &start);
|
|
spin_unlock(&pa->pa_lock);
|
|
printk(KERN_ERR "PA:%u:%d:%u \n", i,
|
|
start, pa->pa_len);
|
|
}
|
|
ext4_unlock_group(sb, i);
|
|
|
|
if (grp->bb_free == 0)
|
|
continue;
|
|
printk(KERN_ERR "%u: %d/%d \n",
|
|
i, grp->bb_free, grp->bb_fragments);
|
|
}
|
|
printk(KERN_ERR "\n");
|
|
}
|
|
#else
|
|
static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
|
|
{
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* We use locality group preallocation for small size file. The size of the
|
|
* file is determined by the current size or the resulting size after
|
|
* allocation which ever is larger
|
|
*
|
|
* One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
|
|
*/
|
|
static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
int bsbits = ac->ac_sb->s_blocksize_bits;
|
|
loff_t size, isize;
|
|
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
|
|
return;
|
|
|
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
|
|
return;
|
|
|
|
size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
|
|
isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
|
|
>> bsbits;
|
|
|
|
if ((size == isize) && !ext4_fs_is_busy(sbi) &&
|
|
!inode_is_open_for_write(ac->ac_inode)) {
|
|
ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
|
|
return;
|
|
}
|
|
|
|
if (sbi->s_mb_group_prealloc <= 0) {
|
|
ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
|
|
return;
|
|
}
|
|
|
|
/* don't use group allocation for large files */
|
|
size = max(size, isize);
|
|
if (size > sbi->s_mb_stream_request) {
|
|
ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
|
|
return;
|
|
}
|
|
|
|
BUG_ON(ac->ac_lg != NULL);
|
|
/*
|
|
* locality group prealloc space are per cpu. The reason for having
|
|
* per cpu locality group is to reduce the contention between block
|
|
* request from multiple CPUs.
|
|
*/
|
|
ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
|
|
|
|
/* we're going to use group allocation */
|
|
ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
|
|
|
|
/* serialize all allocations in the group */
|
|
mutex_lock(&ac->ac_lg->lg_mutex);
|
|
}
|
|
|
|
static noinline_for_stack int
|
|
ext4_mb_initialize_context(struct ext4_allocation_context *ac,
|
|
struct ext4_allocation_request *ar)
|
|
{
|
|
struct super_block *sb = ar->inode->i_sb;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct ext4_super_block *es = sbi->s_es;
|
|
ext4_group_t group;
|
|
unsigned int len;
|
|
ext4_fsblk_t goal;
|
|
ext4_grpblk_t block;
|
|
|
|
/* we can't allocate > group size */
|
|
len = ar->len;
|
|
|
|
/* just a dirty hack to filter too big requests */
|
|
if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
|
|
len = EXT4_CLUSTERS_PER_GROUP(sb);
|
|
|
|
/* start searching from the goal */
|
|
goal = ar->goal;
|
|
if (goal < le32_to_cpu(es->s_first_data_block) ||
|
|
goal >= ext4_blocks_count(es))
|
|
goal = le32_to_cpu(es->s_first_data_block);
|
|
ext4_get_group_no_and_offset(sb, goal, &group, &block);
|
|
|
|
/* set up allocation goals */
|
|
ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
|
|
ac->ac_status = AC_STATUS_CONTINUE;
|
|
ac->ac_sb = sb;
|
|
ac->ac_inode = ar->inode;
|
|
ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
|
|
ac->ac_o_ex.fe_group = group;
|
|
ac->ac_o_ex.fe_start = block;
|
|
ac->ac_o_ex.fe_len = len;
|
|
ac->ac_g_ex = ac->ac_o_ex;
|
|
ac->ac_flags = ar->flags;
|
|
|
|
/* we have to define context: we'll we work with a file or
|
|
* locality group. this is a policy, actually */
|
|
ext4_mb_group_or_file(ac);
|
|
|
|
mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
|
|
"left: %u/%u, right %u/%u to %swritable\n",
|
|
(unsigned) ar->len, (unsigned) ar->logical,
|
|
(unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
|
|
(unsigned) ar->lleft, (unsigned) ar->pleft,
|
|
(unsigned) ar->lright, (unsigned) ar->pright,
|
|
inode_is_open_for_write(ar->inode) ? "" : "non-");
|
|
return 0;
|
|
|
|
}
|
|
|
|
static noinline_for_stack void
|
|
ext4_mb_discard_lg_preallocations(struct super_block *sb,
|
|
struct ext4_locality_group *lg,
|
|
int order, int total_entries)
|
|
{
|
|
ext4_group_t group = 0;
|
|
struct ext4_buddy e4b;
|
|
struct list_head discard_list;
|
|
struct ext4_prealloc_space *pa, *tmp;
|
|
|
|
mb_debug(1, "discard locality group preallocation\n");
|
|
|
|
INIT_LIST_HEAD(&discard_list);
|
|
|
|
spin_lock(&lg->lg_prealloc_lock);
|
|
list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
|
|
pa_inode_list) {
|
|
spin_lock(&pa->pa_lock);
|
|
if (atomic_read(&pa->pa_count)) {
|
|
/*
|
|
* This is the pa that we just used
|
|
* for block allocation. So don't
|
|
* free that
|
|
*/
|
|
spin_unlock(&pa->pa_lock);
|
|
continue;
|
|
}
|
|
if (pa->pa_deleted) {
|
|
spin_unlock(&pa->pa_lock);
|
|
continue;
|
|
}
|
|
/* only lg prealloc space */
|
|
BUG_ON(pa->pa_type != MB_GROUP_PA);
|
|
|
|
/* seems this one can be freed ... */
|
|
pa->pa_deleted = 1;
|
|
spin_unlock(&pa->pa_lock);
|
|
|
|
list_del_rcu(&pa->pa_inode_list);
|
|
list_add(&pa->u.pa_tmp_list, &discard_list);
|
|
|
|
total_entries--;
|
|
if (total_entries <= 5) {
|
|
/*
|
|
* we want to keep only 5 entries
|
|
* allowing it to grow to 8. This
|
|
* mak sure we don't call discard
|
|
* soon for this list.
|
|
*/
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&lg->lg_prealloc_lock);
|
|
|
|
list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
|
|
int err;
|
|
|
|
group = ext4_get_group_number(sb, pa->pa_pstart);
|
|
err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
|
|
GFP_NOFS|__GFP_NOFAIL);
|
|
if (err) {
|
|
ext4_error(sb, "Error %d loading buddy information for %u",
|
|
err, group);
|
|
continue;
|
|
}
|
|
ext4_lock_group(sb, group);
|
|
list_del(&pa->pa_group_list);
|
|
ext4_mb_release_group_pa(&e4b, pa);
|
|
ext4_unlock_group(sb, group);
|
|
|
|
ext4_mb_unload_buddy(&e4b);
|
|
list_del(&pa->u.pa_tmp_list);
|
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We have incremented pa_count. So it cannot be freed at this
|
|
* point. Also we hold lg_mutex. So no parallel allocation is
|
|
* possible from this lg. That means pa_free cannot be updated.
|
|
*
|
|
* A parallel ext4_mb_discard_group_preallocations is possible.
|
|
* which can cause the lg_prealloc_list to be updated.
|
|
*/
|
|
|
|
static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
|
|
{
|
|
int order, added = 0, lg_prealloc_count = 1;
|
|
struct super_block *sb = ac->ac_sb;
|
|
struct ext4_locality_group *lg = ac->ac_lg;
|
|
struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
|
|
|
|
order = fls(pa->pa_free) - 1;
|
|
if (order > PREALLOC_TB_SIZE - 1)
|
|
/* The max size of hash table is PREALLOC_TB_SIZE */
|
|
order = PREALLOC_TB_SIZE - 1;
|
|
/* Add the prealloc space to lg */
|
|
spin_lock(&lg->lg_prealloc_lock);
|
|
list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
|
|
pa_inode_list) {
|
|
spin_lock(&tmp_pa->pa_lock);
|
|
if (tmp_pa->pa_deleted) {
|
|
spin_unlock(&tmp_pa->pa_lock);
|
|
continue;
|
|
}
|
|
if (!added && pa->pa_free < tmp_pa->pa_free) {
|
|
/* Add to the tail of the previous entry */
|
|
list_add_tail_rcu(&pa->pa_inode_list,
|
|
&tmp_pa->pa_inode_list);
|
|
added = 1;
|
|
/*
|
|
* we want to count the total
|
|
* number of entries in the list
|
|
*/
|
|
}
|
|
spin_unlock(&tmp_pa->pa_lock);
|
|
lg_prealloc_count++;
|
|
}
|
|
if (!added)
|
|
list_add_tail_rcu(&pa->pa_inode_list,
|
|
&lg->lg_prealloc_list[order]);
|
|
spin_unlock(&lg->lg_prealloc_lock);
|
|
|
|
/* Now trim the list to be not more than 8 elements */
|
|
if (lg_prealloc_count > 8) {
|
|
ext4_mb_discard_lg_preallocations(sb, lg,
|
|
order, lg_prealloc_count);
|
|
return;
|
|
}
|
|
return ;
|
|
}
|
|
|
|
/*
|
|
* release all resource we used in allocation
|
|
*/
|
|
static int ext4_mb_release_context(struct ext4_allocation_context *ac)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
|
|
struct ext4_prealloc_space *pa = ac->ac_pa;
|
|
if (pa) {
|
|
if (pa->pa_type == MB_GROUP_PA) {
|
|
/* see comment in ext4_mb_use_group_pa() */
|
|
spin_lock(&pa->pa_lock);
|
|
pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
|
|
pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
|
|
pa->pa_free -= ac->ac_b_ex.fe_len;
|
|
pa->pa_len -= ac->ac_b_ex.fe_len;
|
|
spin_unlock(&pa->pa_lock);
|
|
}
|
|
}
|
|
if (pa) {
|
|
/*
|
|
* We want to add the pa to the right bucket.
|
|
* Remove it from the list and while adding
|
|
* make sure the list to which we are adding
|
|
* doesn't grow big.
|
|
*/
|
|
if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) {
|
|
spin_lock(pa->pa_obj_lock);
|
|
list_del_rcu(&pa->pa_inode_list);
|
|
spin_unlock(pa->pa_obj_lock);
|
|
ext4_mb_add_n_trim(ac);
|
|
}
|
|
ext4_mb_put_pa(ac, ac->ac_sb, pa);
|
|
}
|
|
if (ac->ac_bitmap_page)
|
|
put_page(ac->ac_bitmap_page);
|
|
if (ac->ac_buddy_page)
|
|
put_page(ac->ac_buddy_page);
|
|
if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
|
|
mutex_unlock(&ac->ac_lg->lg_mutex);
|
|
ext4_mb_collect_stats(ac);
|
|
return 0;
|
|
}
|
|
|
|
static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
|
|
{
|
|
ext4_group_t i, ngroups = ext4_get_groups_count(sb);
|
|
int ret;
|
|
int freed = 0;
|
|
|
|
trace_ext4_mb_discard_preallocations(sb, needed);
|
|
for (i = 0; i < ngroups && needed > 0; i++) {
|
|
ret = ext4_mb_discard_group_preallocations(sb, i, needed);
|
|
freed += ret;
|
|
needed -= ret;
|
|
}
|
|
|
|
return freed;
|
|
}
|
|
|
|
/*
|
|
* Main entry point into mballoc to allocate blocks
|
|
* it tries to use preallocation first, then falls back
|
|
* to usual allocation
|
|
*/
|
|
ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
|
|
struct ext4_allocation_request *ar, int *errp)
|
|
{
|
|
int freed;
|
|
struct ext4_allocation_context *ac = NULL;
|
|
struct ext4_sb_info *sbi;
|
|
struct super_block *sb;
|
|
ext4_fsblk_t block = 0;
|
|
unsigned int inquota = 0;
|
|
unsigned int reserv_clstrs = 0;
|
|
|
|
might_sleep();
|
|
sb = ar->inode->i_sb;
|
|
sbi = EXT4_SB(sb);
|
|
|
|
trace_ext4_request_blocks(ar);
|
|
|
|
/* Allow to use superuser reservation for quota file */
|
|
if (ext4_is_quota_file(ar->inode))
|
|
ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
|
|
|
|
if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
|
|
/* Without delayed allocation we need to verify
|
|
* there is enough free blocks to do block allocation
|
|
* and verify allocation doesn't exceed the quota limits.
|
|
*/
|
|
while (ar->len &&
|
|
ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
|
|
|
|
/* let others to free the space */
|
|
cond_resched();
|
|
ar->len = ar->len >> 1;
|
|
}
|
|
if (!ar->len) {
|
|
*errp = -ENOSPC;
|
|
return 0;
|
|
}
|
|
reserv_clstrs = ar->len;
|
|
if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
|
|
dquot_alloc_block_nofail(ar->inode,
|
|
EXT4_C2B(sbi, ar->len));
|
|
} else {
|
|
while (ar->len &&
|
|
dquot_alloc_block(ar->inode,
|
|
EXT4_C2B(sbi, ar->len))) {
|
|
|
|
ar->flags |= EXT4_MB_HINT_NOPREALLOC;
|
|
ar->len--;
|
|
}
|
|
}
|
|
inquota = ar->len;
|
|
if (ar->len == 0) {
|
|
*errp = -EDQUOT;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
|
|
if (!ac) {
|
|
ar->len = 0;
|
|
*errp = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
*errp = ext4_mb_initialize_context(ac, ar);
|
|
if (*errp) {
|
|
ar->len = 0;
|
|
goto out;
|
|
}
|
|
|
|
ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
|
|
if (!ext4_mb_use_preallocated(ac)) {
|
|
ac->ac_op = EXT4_MB_HISTORY_ALLOC;
|
|
ext4_mb_normalize_request(ac, ar);
|
|
repeat:
|
|
/* allocate space in core */
|
|
*errp = ext4_mb_regular_allocator(ac);
|
|
if (*errp)
|
|
goto discard_and_exit;
|
|
|
|
/* as we've just preallocated more space than
|
|
* user requested originally, we store allocated
|
|
* space in a special descriptor */
|
|
if (ac->ac_status == AC_STATUS_FOUND &&
|
|
ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
|
|
*errp = ext4_mb_new_preallocation(ac);
|
|
if (*errp) {
|
|
discard_and_exit:
|
|
ext4_discard_allocated_blocks(ac);
|
|
goto errout;
|
|
}
|
|
}
|
|
if (likely(ac->ac_status == AC_STATUS_FOUND)) {
|
|
*errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
|
|
if (*errp) {
|
|
ext4_discard_allocated_blocks(ac);
|
|
goto errout;
|
|
} else {
|
|
block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
|
|
ar->len = ac->ac_b_ex.fe_len;
|
|
}
|
|
} else {
|
|
freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
|
|
if (freed)
|
|
goto repeat;
|
|
*errp = -ENOSPC;
|
|
}
|
|
|
|
errout:
|
|
if (*errp) {
|
|
ac->ac_b_ex.fe_len = 0;
|
|
ar->len = 0;
|
|
ext4_mb_show_ac(ac);
|
|
}
|
|
ext4_mb_release_context(ac);
|
|
out:
|
|
if (ac)
|
|
kmem_cache_free(ext4_ac_cachep, ac);
|
|
if (inquota && ar->len < inquota)
|
|
dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
|
|
if (!ar->len) {
|
|
if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
|
|
/* release all the reserved blocks if non delalloc */
|
|
percpu_counter_sub(&sbi->s_dirtyclusters_counter,
|
|
reserv_clstrs);
|
|
}
|
|
|
|
trace_ext4_allocate_blocks(ar, (unsigned long long)block);
|
|
|
|
return block;
|
|
}
|
|
|
|
/*
|
|
* We can merge two free data extents only if the physical blocks
|
|
* are contiguous, AND the extents were freed by the same transaction,
|
|
* AND the blocks are associated with the same group.
|
|
*/
|
|
static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
|
|
struct ext4_free_data *entry,
|
|
struct ext4_free_data *new_entry,
|
|
struct rb_root *entry_rb_root)
|
|
{
|
|
if ((entry->efd_tid != new_entry->efd_tid) ||
|
|
(entry->efd_group != new_entry->efd_group))
|
|
return;
|
|
if (entry->efd_start_cluster + entry->efd_count ==
|
|
new_entry->efd_start_cluster) {
|
|
new_entry->efd_start_cluster = entry->efd_start_cluster;
|
|
new_entry->efd_count += entry->efd_count;
|
|
} else if (new_entry->efd_start_cluster + new_entry->efd_count ==
|
|
entry->efd_start_cluster) {
|
|
new_entry->efd_count += entry->efd_count;
|
|
} else
|
|
return;
|
|
spin_lock(&sbi->s_md_lock);
|
|
list_del(&entry->efd_list);
|
|
spin_unlock(&sbi->s_md_lock);
|
|
rb_erase(&entry->efd_node, entry_rb_root);
|
|
kmem_cache_free(ext4_free_data_cachep, entry);
|
|
}
|
|
|
|
static noinline_for_stack int
|
|
ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
|
|
struct ext4_free_data *new_entry)
|
|
{
|
|
ext4_group_t group = e4b->bd_group;
|
|
ext4_grpblk_t cluster;
|
|
ext4_grpblk_t clusters = new_entry->efd_count;
|
|
struct ext4_free_data *entry;
|
|
struct ext4_group_info *db = e4b->bd_info;
|
|
struct super_block *sb = e4b->bd_sb;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct rb_node **n = &db->bb_free_root.rb_node, *node;
|
|
struct rb_node *parent = NULL, *new_node;
|
|
|
|
BUG_ON(!ext4_handle_valid(handle));
|
|
BUG_ON(e4b->bd_bitmap_page == NULL);
|
|
BUG_ON(e4b->bd_buddy_page == NULL);
|
|
|
|
new_node = &new_entry->efd_node;
|
|
cluster = new_entry->efd_start_cluster;
|
|
|
|
if (!*n) {
|
|
/* first free block exent. We need to
|
|
protect buddy cache from being freed,
|
|
* otherwise we'll refresh it from
|
|
* on-disk bitmap and lose not-yet-available
|
|
* blocks */
|
|
get_page(e4b->bd_buddy_page);
|
|
get_page(e4b->bd_bitmap_page);
|
|
}
|
|
while (*n) {
|
|
parent = *n;
|
|
entry = rb_entry(parent, struct ext4_free_data, efd_node);
|
|
if (cluster < entry->efd_start_cluster)
|
|
n = &(*n)->rb_left;
|
|
else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
|
|
n = &(*n)->rb_right;
|
|
else {
|
|
ext4_grp_locked_error(sb, group, 0,
|
|
ext4_group_first_block_no(sb, group) +
|
|
EXT4_C2B(sbi, cluster),
|
|
"Block already on to-be-freed list");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
rb_link_node(new_node, parent, n);
|
|
rb_insert_color(new_node, &db->bb_free_root);
|
|
|
|
/* Now try to see the extent can be merged to left and right */
|
|
node = rb_prev(new_node);
|
|
if (node) {
|
|
entry = rb_entry(node, struct ext4_free_data, efd_node);
|
|
ext4_try_merge_freed_extent(sbi, entry, new_entry,
|
|
&(db->bb_free_root));
|
|
}
|
|
|
|
node = rb_next(new_node);
|
|
if (node) {
|
|
entry = rb_entry(node, struct ext4_free_data, efd_node);
|
|
ext4_try_merge_freed_extent(sbi, entry, new_entry,
|
|
&(db->bb_free_root));
|
|
}
|
|
|
|
spin_lock(&sbi->s_md_lock);
|
|
list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
|
|
sbi->s_mb_free_pending += clusters;
|
|
spin_unlock(&sbi->s_md_lock);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ext4_free_blocks() -- Free given blocks and update quota
|
|
* @handle: handle for this transaction
|
|
* @inode: inode
|
|
* @bh: optional buffer of the block to be freed
|
|
* @block: starting physical block to be freed
|
|
* @count: number of blocks to be freed
|
|
* @flags: flags used by ext4_free_blocks
|
|
*/
|
|
void ext4_free_blocks(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *bh, ext4_fsblk_t block,
|
|
unsigned long count, int flags)
|
|
{
|
|
struct buffer_head *bitmap_bh = NULL;
|
|
struct super_block *sb = inode->i_sb;
|
|
struct ext4_group_desc *gdp;
|
|
unsigned int overflow;
|
|
ext4_grpblk_t bit;
|
|
struct buffer_head *gd_bh;
|
|
ext4_group_t block_group;
|
|
struct ext4_sb_info *sbi;
|
|
struct ext4_buddy e4b;
|
|
unsigned int count_clusters;
|
|
int err = 0;
|
|
int ret;
|
|
|
|
might_sleep();
|
|
if (bh) {
|
|
if (block)
|
|
BUG_ON(block != bh->b_blocknr);
|
|
else
|
|
block = bh->b_blocknr;
|
|
}
|
|
|
|
sbi = EXT4_SB(sb);
|
|
if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
|
|
!ext4_data_block_valid(sbi, block, count)) {
|
|
ext4_error(sb, "Freeing blocks not in datazone - "
|
|
"block = %llu, count = %lu", block, count);
|
|
goto error_return;
|
|
}
|
|
|
|
ext4_debug("freeing block %llu\n", block);
|
|
trace_ext4_free_blocks(inode, block, count, flags);
|
|
|
|
if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
|
|
BUG_ON(count > 1);
|
|
|
|
ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
|
|
inode, bh, block);
|
|
}
|
|
|
|
/*
|
|
* If the extent to be freed does not begin on a cluster
|
|
* boundary, we need to deal with partial clusters at the
|
|
* beginning and end of the extent. Normally we will free
|
|
* blocks at the beginning or the end unless we are explicitly
|
|
* requested to avoid doing so.
|
|
*/
|
|
overflow = EXT4_PBLK_COFF(sbi, block);
|
|
if (overflow) {
|
|
if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
|
|
overflow = sbi->s_cluster_ratio - overflow;
|
|
block += overflow;
|
|
if (count > overflow)
|
|
count -= overflow;
|
|
else
|
|
return;
|
|
} else {
|
|
block -= overflow;
|
|
count += overflow;
|
|
}
|
|
}
|
|
overflow = EXT4_LBLK_COFF(sbi, count);
|
|
if (overflow) {
|
|
if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
|
|
if (count > overflow)
|
|
count -= overflow;
|
|
else
|
|
return;
|
|
} else
|
|
count += sbi->s_cluster_ratio - overflow;
|
|
}
|
|
|
|
if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
|
|
int i;
|
|
int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
cond_resched();
|
|
if (is_metadata)
|
|
bh = sb_find_get_block(inode->i_sb, block + i);
|
|
ext4_forget(handle, is_metadata, inode, bh, block + i);
|
|
}
|
|
}
|
|
|
|
do_more:
|
|
overflow = 0;
|
|
ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
|
|
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
|
|
ext4_get_group_info(sb, block_group))))
|
|
return;
|
|
|
|
/*
|
|
* Check to see if we are freeing blocks across a group
|
|
* boundary.
|
|
*/
|
|
if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
|
|
overflow = EXT4_C2B(sbi, bit) + count -
|
|
EXT4_BLOCKS_PER_GROUP(sb);
|
|
count -= overflow;
|
|
}
|
|
count_clusters = EXT4_NUM_B2C(sbi, count);
|
|
bitmap_bh = ext4_read_block_bitmap(sb, block_group);
|
|
if (IS_ERR(bitmap_bh)) {
|
|
err = PTR_ERR(bitmap_bh);
|
|
bitmap_bh = NULL;
|
|
goto error_return;
|
|
}
|
|
gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
|
|
if (!gdp) {
|
|
err = -EIO;
|
|
goto error_return;
|
|
}
|
|
|
|
if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
|
|
in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
|
|
in_range(block, ext4_inode_table(sb, gdp),
|
|
sbi->s_itb_per_group) ||
|
|
in_range(block + count - 1, ext4_inode_table(sb, gdp),
|
|
sbi->s_itb_per_group)) {
|
|
|
|
ext4_error(sb, "Freeing blocks in system zone - "
|
|
"Block = %llu, count = %lu", block, count);
|
|
/* err = 0. ext4_std_error should be a no op */
|
|
goto error_return;
|
|
}
|
|
|
|
BUFFER_TRACE(bitmap_bh, "getting write access");
|
|
err = ext4_journal_get_write_access(handle, bitmap_bh);
|
|
if (err)
|
|
goto error_return;
|
|
|
|
/*
|
|
* We are about to modify some metadata. Call the journal APIs
|
|
* to unshare ->b_data if a currently-committing transaction is
|
|
* using it
|
|
*/
|
|
BUFFER_TRACE(gd_bh, "get_write_access");
|
|
err = ext4_journal_get_write_access(handle, gd_bh);
|
|
if (err)
|
|
goto error_return;
|
|
#ifdef AGGRESSIVE_CHECK
|
|
{
|
|
int i;
|
|
for (i = 0; i < count_clusters; i++)
|
|
BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
|
|
}
|
|
#endif
|
|
trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
|
|
|
|
/* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
|
|
err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
|
|
GFP_NOFS|__GFP_NOFAIL);
|
|
if (err)
|
|
goto error_return;
|
|
|
|
/*
|
|
* We need to make sure we don't reuse the freed block until after the
|
|
* transaction is committed. We make an exception if the inode is to be
|
|
* written in writeback mode since writeback mode has weak data
|
|
* consistency guarantees.
|
|
*/
|
|
if (ext4_handle_valid(handle) &&
|
|
((flags & EXT4_FREE_BLOCKS_METADATA) ||
|
|
!ext4_should_writeback_data(inode))) {
|
|
struct ext4_free_data *new_entry;
|
|
/*
|
|
* We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
|
|
* to fail.
|
|
*/
|
|
new_entry = kmem_cache_alloc(ext4_free_data_cachep,
|
|
GFP_NOFS|__GFP_NOFAIL);
|
|
new_entry->efd_start_cluster = bit;
|
|
new_entry->efd_group = block_group;
|
|
new_entry->efd_count = count_clusters;
|
|
new_entry->efd_tid = handle->h_transaction->t_tid;
|
|
|
|
ext4_lock_group(sb, block_group);
|
|
mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
|
|
ext4_mb_free_metadata(handle, &e4b, new_entry);
|
|
} else {
|
|
/* need to update group_info->bb_free and bitmap
|
|
* with group lock held. generate_buddy look at
|
|
* them with group lock_held
|
|
*/
|
|
if (test_opt(sb, DISCARD)) {
|
|
err = ext4_issue_discard(sb, block_group, bit, count,
|
|
NULL);
|
|
if (err && err != -EOPNOTSUPP)
|
|
ext4_msg(sb, KERN_WARNING, "discard request in"
|
|
" group:%d block:%d count:%lu failed"
|
|
" with %d", block_group, bit, count,
|
|
err);
|
|
} else
|
|
EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
|
|
|
|
ext4_lock_group(sb, block_group);
|
|
mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
|
|
mb_free_blocks(inode, &e4b, bit, count_clusters);
|
|
}
|
|
|
|
ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
|
|
ext4_free_group_clusters_set(sb, gdp, ret);
|
|
ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
|
|
ext4_group_desc_csum_set(sb, block_group, gdp);
|
|
ext4_unlock_group(sb, block_group);
|
|
|
|
if (sbi->s_log_groups_per_flex) {
|
|
ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
|
|
atomic64_add(count_clusters,
|
|
&sbi->s_flex_groups[flex_group].free_clusters);
|
|
}
|
|
|
|
/*
|
|
* on a bigalloc file system, defer the s_freeclusters_counter
|
|
* update to the caller (ext4_remove_space and friends) so they
|
|
* can determine if a cluster freed here should be rereserved
|
|
*/
|
|
if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
|
|
if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
|
|
dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
|
|
percpu_counter_add(&sbi->s_freeclusters_counter,
|
|
count_clusters);
|
|
}
|
|
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
/* We dirtied the bitmap block */
|
|
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
|
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
|
|
|
|
/* And the group descriptor block */
|
|
BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
|
|
ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
|
|
if (!err)
|
|
err = ret;
|
|
|
|
if (overflow && !err) {
|
|
block += count;
|
|
count = overflow;
|
|
put_bh(bitmap_bh);
|
|
goto do_more;
|
|
}
|
|
error_return:
|
|
brelse(bitmap_bh);
|
|
ext4_std_error(sb, err);
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* ext4_group_add_blocks() -- Add given blocks to an existing group
|
|
* @handle: handle to this transaction
|
|
* @sb: super block
|
|
* @block: start physical block to add to the block group
|
|
* @count: number of blocks to free
|
|
*
|
|
* This marks the blocks as free in the bitmap and buddy.
|
|
*/
|
|
int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
|
|
ext4_fsblk_t block, unsigned long count)
|
|
{
|
|
struct buffer_head *bitmap_bh = NULL;
|
|
struct buffer_head *gd_bh;
|
|
ext4_group_t block_group;
|
|
ext4_grpblk_t bit;
|
|
unsigned int i;
|
|
struct ext4_group_desc *desc;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct ext4_buddy e4b;
|
|
int err = 0, ret, free_clusters_count;
|
|
ext4_grpblk_t clusters_freed;
|
|
ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
|
|
ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
|
|
unsigned long cluster_count = last_cluster - first_cluster + 1;
|
|
|
|
ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
|
|
|
|
if (count == 0)
|
|
return 0;
|
|
|
|
ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
|
|
/*
|
|
* Check to see if we are freeing blocks across a group
|
|
* boundary.
|
|
*/
|
|
if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
|
|
ext4_warning(sb, "too many blocks added to group %u",
|
|
block_group);
|
|
err = -EINVAL;
|
|
goto error_return;
|
|
}
|
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, block_group);
|
|
if (IS_ERR(bitmap_bh)) {
|
|
err = PTR_ERR(bitmap_bh);
|
|
bitmap_bh = NULL;
|
|
goto error_return;
|
|
}
|
|
|
|
desc = ext4_get_group_desc(sb, block_group, &gd_bh);
|
|
if (!desc) {
|
|
err = -EIO;
|
|
goto error_return;
|
|
}
|
|
|
|
if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
|
|
in_range(ext4_inode_bitmap(sb, desc), block, count) ||
|
|
in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
|
|
in_range(block + count - 1, ext4_inode_table(sb, desc),
|
|
sbi->s_itb_per_group)) {
|
|
ext4_error(sb, "Adding blocks in system zones - "
|
|
"Block = %llu, count = %lu",
|
|
block, count);
|
|
err = -EINVAL;
|
|
goto error_return;
|
|
}
|
|
|
|
BUFFER_TRACE(bitmap_bh, "getting write access");
|
|
err = ext4_journal_get_write_access(handle, bitmap_bh);
|
|
if (err)
|
|
goto error_return;
|
|
|
|
/*
|
|
* We are about to modify some metadata. Call the journal APIs
|
|
* to unshare ->b_data if a currently-committing transaction is
|
|
* using it
|
|
*/
|
|
BUFFER_TRACE(gd_bh, "get_write_access");
|
|
err = ext4_journal_get_write_access(handle, gd_bh);
|
|
if (err)
|
|
goto error_return;
|
|
|
|
for (i = 0, clusters_freed = 0; i < cluster_count; i++) {
|
|
BUFFER_TRACE(bitmap_bh, "clear bit");
|
|
if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
|
|
ext4_error(sb, "bit already cleared for block %llu",
|
|
(ext4_fsblk_t)(block + i));
|
|
BUFFER_TRACE(bitmap_bh, "bit already cleared");
|
|
} else {
|
|
clusters_freed++;
|
|
}
|
|
}
|
|
|
|
err = ext4_mb_load_buddy(sb, block_group, &e4b);
|
|
if (err)
|
|
goto error_return;
|
|
|
|
/*
|
|
* need to update group_info->bb_free and bitmap
|
|
* with group lock held. generate_buddy look at
|
|
* them with group lock_held
|
|
*/
|
|
ext4_lock_group(sb, block_group);
|
|
mb_clear_bits(bitmap_bh->b_data, bit, cluster_count);
|
|
mb_free_blocks(NULL, &e4b, bit, cluster_count);
|
|
free_clusters_count = clusters_freed +
|
|
ext4_free_group_clusters(sb, desc);
|
|
ext4_free_group_clusters_set(sb, desc, free_clusters_count);
|
|
ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
|
|
ext4_group_desc_csum_set(sb, block_group, desc);
|
|
ext4_unlock_group(sb, block_group);
|
|
percpu_counter_add(&sbi->s_freeclusters_counter,
|
|
clusters_freed);
|
|
|
|
if (sbi->s_log_groups_per_flex) {
|
|
ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
|
|
atomic64_add(clusters_freed,
|
|
&sbi->s_flex_groups[flex_group].free_clusters);
|
|
}
|
|
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
/* We dirtied the bitmap block */
|
|
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
|
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
|
|
|
|
/* And the group descriptor block */
|
|
BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
|
|
ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
|
|
if (!err)
|
|
err = ret;
|
|
|
|
error_return:
|
|
brelse(bitmap_bh);
|
|
ext4_std_error(sb, err);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ext4_trim_extent -- function to TRIM one single free extent in the group
|
|
* @sb: super block for the file system
|
|
* @start: starting block of the free extent in the alloc. group
|
|
* @count: number of blocks to TRIM
|
|
* @group: alloc. group we are working with
|
|
* @e4b: ext4 buddy for the group
|
|
*
|
|
* Trim "count" blocks starting at "start" in the "group". To assure that no
|
|
* one will allocate those blocks, mark it as used in buddy bitmap. This must
|
|
* be called with under the group lock.
|
|
*/
|
|
static int ext4_trim_extent(struct super_block *sb, int start, int count,
|
|
ext4_group_t group, struct ext4_buddy *e4b)
|
|
__releases(bitlock)
|
|
__acquires(bitlock)
|
|
{
|
|
struct ext4_free_extent ex;
|
|
int ret = 0;
|
|
|
|
trace_ext4_trim_extent(sb, group, start, count);
|
|
|
|
assert_spin_locked(ext4_group_lock_ptr(sb, group));
|
|
|
|
ex.fe_start = start;
|
|
ex.fe_group = group;
|
|
ex.fe_len = count;
|
|
|
|
/*
|
|
* Mark blocks used, so no one can reuse them while
|
|
* being trimmed.
|
|
*/
|
|
mb_mark_used(e4b, &ex);
|
|
ext4_unlock_group(sb, group);
|
|
ret = ext4_issue_discard(sb, group, start, count, NULL);
|
|
ext4_lock_group(sb, group);
|
|
mb_free_blocks(NULL, e4b, start, ex.fe_len);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* ext4_trim_all_free -- function to trim all free space in alloc. group
|
|
* @sb: super block for file system
|
|
* @group: group to be trimmed
|
|
* @start: first group block to examine
|
|
* @max: last group block to examine
|
|
* @minblocks: minimum extent block count
|
|
*
|
|
* ext4_trim_all_free walks through group's buddy bitmap searching for free
|
|
* extents. When the free block is found, ext4_trim_extent is called to TRIM
|
|
* the extent.
|
|
*
|
|
*
|
|
* ext4_trim_all_free walks through group's block bitmap searching for free
|
|
* extents. When the free extent is found, mark it as used in group buddy
|
|
* bitmap. Then issue a TRIM command on this extent and free the extent in
|
|
* the group buddy bitmap. This is done until whole group is scanned.
|
|
*/
|
|
static ext4_grpblk_t
|
|
ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
|
|
ext4_grpblk_t start, ext4_grpblk_t max,
|
|
ext4_grpblk_t minblocks)
|
|
{
|
|
void *bitmap;
|
|
ext4_grpblk_t next, count = 0, free_count = 0;
|
|
struct ext4_buddy e4b;
|
|
int ret = 0;
|
|
|
|
trace_ext4_trim_all_free(sb, group, start, max);
|
|
|
|
ret = ext4_mb_load_buddy(sb, group, &e4b);
|
|
if (ret) {
|
|
ext4_warning(sb, "Error %d loading buddy information for %u",
|
|
ret, group);
|
|
return ret;
|
|
}
|
|
bitmap = e4b.bd_bitmap;
|
|
|
|
ext4_lock_group(sb, group);
|
|
if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
|
|
minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
|
|
goto out;
|
|
|
|
start = (e4b.bd_info->bb_first_free > start) ?
|
|
e4b.bd_info->bb_first_free : start;
|
|
|
|
while (start <= max) {
|
|
start = mb_find_next_zero_bit(bitmap, max + 1, start);
|
|
if (start > max)
|
|
break;
|
|
next = mb_find_next_bit(bitmap, max + 1, start);
|
|
|
|
if ((next - start) >= minblocks) {
|
|
ret = ext4_trim_extent(sb, start,
|
|
next - start, group, &e4b);
|
|
if (ret && ret != -EOPNOTSUPP)
|
|
break;
|
|
ret = 0;
|
|
count += next - start;
|
|
}
|
|
free_count += next - start;
|
|
start = next + 1;
|
|
|
|
if (fatal_signal_pending(current)) {
|
|
count = -ERESTARTSYS;
|
|
break;
|
|
}
|
|
|
|
if (need_resched()) {
|
|
ext4_unlock_group(sb, group);
|
|
cond_resched();
|
|
ext4_lock_group(sb, group);
|
|
}
|
|
|
|
if ((e4b.bd_info->bb_free - free_count) < minblocks)
|
|
break;
|
|
}
|
|
|
|
if (!ret) {
|
|
ret = count;
|
|
EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
|
|
}
|
|
out:
|
|
ext4_unlock_group(sb, group);
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
ext4_debug("trimmed %d blocks in the group %d\n",
|
|
count, group);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* ext4_trim_fs() -- trim ioctl handle function
|
|
* @sb: superblock for filesystem
|
|
* @range: fstrim_range structure
|
|
*
|
|
* start: First Byte to trim
|
|
* len: number of Bytes to trim from start
|
|
* minlen: minimum extent length in Bytes
|
|
* ext4_trim_fs goes through all allocation groups containing Bytes from
|
|
* start to start+len. For each such a group ext4_trim_all_free function
|
|
* is invoked to trim all free space.
|
|
*/
|
|
int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
|
|
{
|
|
struct ext4_group_info *grp;
|
|
ext4_group_t group, first_group, last_group;
|
|
ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
|
|
uint64_t start, end, minlen, trimmed = 0;
|
|
ext4_fsblk_t first_data_blk =
|
|
le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
|
|
ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
|
|
int ret = 0;
|
|
|
|
start = range->start >> sb->s_blocksize_bits;
|
|
end = start + (range->len >> sb->s_blocksize_bits) - 1;
|
|
minlen = EXT4_NUM_B2C(EXT4_SB(sb),
|
|
range->minlen >> sb->s_blocksize_bits);
|
|
|
|
if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
|
|
start >= max_blks ||
|
|
range->len < sb->s_blocksize)
|
|
return -EINVAL;
|
|
if (end >= max_blks)
|
|
end = max_blks - 1;
|
|
if (end <= first_data_blk)
|
|
goto out;
|
|
if (start < first_data_blk)
|
|
start = first_data_blk;
|
|
|
|
/* Determine first and last group to examine based on start and end */
|
|
ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
|
|
&first_group, &first_cluster);
|
|
ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
|
|
&last_group, &last_cluster);
|
|
|
|
/* end now represents the last cluster to discard in this group */
|
|
end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
|
|
|
|
for (group = first_group; group <= last_group; group++) {
|
|
grp = ext4_get_group_info(sb, group);
|
|
/* We only do this if the grp has never been initialized */
|
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
|
|
ret = ext4_mb_init_group(sb, group, GFP_NOFS);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* For all the groups except the last one, last cluster will
|
|
* always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
|
|
* change it for the last group, note that last_cluster is
|
|
* already computed earlier by ext4_get_group_no_and_offset()
|
|
*/
|
|
if (group == last_group)
|
|
end = last_cluster;
|
|
|
|
if (grp->bb_free >= minlen) {
|
|
cnt = ext4_trim_all_free(sb, group, first_cluster,
|
|
end, minlen);
|
|
if (cnt < 0) {
|
|
ret = cnt;
|
|
break;
|
|
}
|
|
trimmed += cnt;
|
|
}
|
|
|
|
/*
|
|
* For every group except the first one, we are sure
|
|
* that the first cluster to discard will be cluster #0.
|
|
*/
|
|
first_cluster = 0;
|
|
}
|
|
|
|
if (!ret)
|
|
atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
|
|
|
|
out:
|
|
range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
|
|
return ret;
|
|
}
|
|
|
|
/* Iterate all the free extents in the group. */
|
|
int
|
|
ext4_mballoc_query_range(
|
|
struct super_block *sb,
|
|
ext4_group_t group,
|
|
ext4_grpblk_t start,
|
|
ext4_grpblk_t end,
|
|
ext4_mballoc_query_range_fn formatter,
|
|
void *priv)
|
|
{
|
|
void *bitmap;
|
|
ext4_grpblk_t next;
|
|
struct ext4_buddy e4b;
|
|
int error;
|
|
|
|
error = ext4_mb_load_buddy(sb, group, &e4b);
|
|
if (error)
|
|
return error;
|
|
bitmap = e4b.bd_bitmap;
|
|
|
|
ext4_lock_group(sb, group);
|
|
|
|
start = (e4b.bd_info->bb_first_free > start) ?
|
|
e4b.bd_info->bb_first_free : start;
|
|
if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
|
|
end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
|
|
|
|
while (start <= end) {
|
|
start = mb_find_next_zero_bit(bitmap, end + 1, start);
|
|
if (start > end)
|
|
break;
|
|
next = mb_find_next_bit(bitmap, end + 1, start);
|
|
|
|
ext4_unlock_group(sb, group);
|
|
error = formatter(sb, group, start, next - start, priv);
|
|
if (error)
|
|
goto out_unload;
|
|
ext4_lock_group(sb, group);
|
|
|
|
start = next + 1;
|
|
}
|
|
|
|
ext4_unlock_group(sb, group);
|
|
out_unload:
|
|
ext4_mb_unload_buddy(&e4b);
|
|
|
|
return error;
|
|
}
|