Before commit 93e72b3c61 ("squashfs: migrate from ll_rw_block
usage to BIO"), compressed blocks read by squashfs were cached in the page
cache, but that is not the case after that commit. That has lead to
squashfs having to re-read a lot of sectors from disk/flash.
For example, the first sectors of every metadata block need to be read
twice from the disk. Once partially to read the length, and a second time
to read the block itself. Also, in linear reads of large files, the last
sectors of one data block are re-read from disk when reading the next data
block, since the compressed blocks are of variable sizes and not aligned
to device blocks. This extra I/O results in a degrade in read performance
of, for example, ~16% in one scenario on my ARM platform using squashfs
with dm-verity and NAND.
Since the decompressed data is cached in the page cache or squashfs'
internal metadata and fragment caches, caching _all_ compressed pages
would lead to a lot of double caching and is undesirable. But make the
code cache any disk blocks which were only partially requested, since
these are the ones likely to include data which is needed by other file
system blocks. This restores read performance in my test scenario.
The compressed block caching is only applied when the disk block size is
equal to the page size, to avoid having to deal with caching sub-page
reads.
[akpm@linux-foundation.org: fs/squashfs/block.c needs linux/pagemap.h]
[vincent.whitchurch@axis.com: fix page update race]
Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-1-d54a7fa23e7b@axis.com
[vincent.whitchurch@axis.com: fix page indices]
Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-2-d54a7fa23e7b@axis.com
[akpm@linux-foundation.org: fix layout, per hch]
Link: https://lkml.kernel.org/r/20230510-squashfs-cache-v4-1-3bd394e1ee71@axis.com
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Merge tag 'fs.idmapped.squashfs.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull squashfs update from Seth Forshee:
"This is a simple patch to enable idmapped mounts for squashfs.
All functionality squashfs needs to support idmapped mounts is already
implemented in generic VFS code, so all that is needed is to set
FS_ALLOW_IDMAP in fs_flags"
* tag 'fs.idmapped.squashfs.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
squashfs: enable idmapped mounts
When squashfs_read_table() returns an error or `sb->s_magic !=
SQUASHFS_MAGIC`, enters the error branch and calls
msblk->thread_ops->destroy(msblk) to destroy msblk. However,
msblk->thread_ops has not been initialized. Therefore, the following
problem is triggered:
==================================================================
BUG: KASAN: null-ptr-deref in squashfs_fill_super+0xe7a/0x13b0
Read of size 8 at addr 0000000000000008 by task swapper/0/1
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc3-next-20221031 #367
Call Trace:
<TASK>
dump_stack_lvl+0x73/0x9f
print_report+0x743/0x759
kasan_report+0xc0/0x120
__asan_load8+0xd3/0x140
squashfs_fill_super+0xe7a/0x13b0
get_tree_bdev+0x27b/0x450
squashfs_get_tree+0x19/0x30
vfs_get_tree+0x49/0x150
path_mount+0xaae/0x1350
init_mount+0xad/0x100
do_mount_root+0xbc/0x1d0
mount_block_root+0x173/0x316
mount_root+0x223/0x236
prepare_namespace+0x1eb/0x237
kernel_init_freeable+0x528/0x576
kernel_init+0x29/0x250
ret_from_fork+0x1f/0x30
</TASK>
==================================================================
To solve this issue, msblk->thread_ops is initialized immediately after
msblk is assigned a value.
Link: https://lkml.kernel.org/r/20221101073343.3961562-1-libaokun1@huawei.com
Fixes: b0645770d3c7 ("squashfs: add the mount parameter theads=<single|multi|percpu>")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Xiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The maximum number of threads in the decompressor_multi.c file is fixed
and cannot be adjusted according to user needs. Therefore, the mount
parameter needs to be added to allow users to configure the number of
threads as required. The upper limit is num_online_cpus() * 2.
Link: https://lkml.kernel.org/r/20221019030930.130456-3-nixiaoming@huawei.com
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Jianguo Chen <chenjianguo3@huawei.com>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series 'squashfs: Add the mount parameter "threads="'.
Currently, Squashfs supports multiple decompressor parallel modes.
However, this mode can be configured only during kernel building and does
not support flexible selection during runtime.
In the current patch set, the mount parameter "threads=" is added to allow
users to select the parallel decompressor mode and configure the number of
decompressors when mounting a file system.
"threads=<single|multi|percpu|1|2|3|...>"
The upper limit is num_online_cpus() * 2.
This patch (of 2):
Squashfs supports three decompression concurrency modes:
Single-thread mode: concurrent reads are blocked and the memory
overhead is small.
Multi-thread mode/percpu mode: reduces concurrent read blocking but
increases memory overhead.
The corresponding schema must be fixed at compile time. During mounting,
the concurrent decompression mode cannot be adjusted based on file read
blocking.
The mount parameter theads=<single|multi|percpu> is added to select
the concurrent decompression mode of a single SquashFS file system
image.
Link: https://lkml.kernel.org/r/20221019030930.130456-1-nixiaoming@huawei.com
Link: https://lkml.kernel.org/r/20221019030930.130456-2-nixiaoming@huawei.com
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Jianguo Chen <chenjianguo3@huawei.com>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
For squashfs all needed functionality for idmapped mounts is already
implemented by the generic handlers in the VFS. Thus, it is sufficient
to just enable the corresponding FS_ALLOW_IDMAP flag to support
idmapped mounts.
We use this for unprivileged (user namespaced) containers based on
squashfs images as rootfs in GyroidOS.
A simple test using the mount-idmapped tool executed as user with
uid=1000 looks as follows:
$ mkdir test
$ echo "test" > test/test_file
$ mksquashfs test/ fs.img
$ sudo mkdir /mnt/test
$ sudo mkdir /mnt/mapped
$ sudo mount fs.img -o loop /mnt/test/
$ sudo ./mount-idmapped --map-mount b:1000:2000:1 /mnt/test/ /mnt/mapped/
$ mount | tail -n2
fs.img on /mnt/test type squashfs (ro,relatime,errors=continue)
fs.img on /mnt/mapped type squashfs (ro,relatime,idmapped,errors=continue)
$ ls -lan /mnt/test/
total 5
drwxr-xr-x 2 1000 1000 32 Okt 24 13:36 .
drwxr-xr-x 6 0 0 4096 Okt 24 13:38 ..
-rw-r--r-- 1 1000 1000 5 Okt 24 13:36 test_file
$ ls -lan /mnt/mapped/
total 5
drwxr-xr-x 2 2000 2000 32 Okt 24 13:36 .
drwxr-xr-x 6 0 0 4096 Okt 24 13:38 ..
-rw-r--r-- 1 2000 2000 5 Okt 24 13:36 test_file
Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Patch series "Implement readahead for squashfs", v7.
Commit 9eec1d897139("squashfs: provide backing_dev_info in order to
disable read-ahead") mitigates the performance drop issue for squashfs by
closing readahead for it.
This series implements readahead callback for squashfs.
This patch (of 4):
This reverts 9eec1d8971 ("squashfs: provide backing_dev_info in order
to disable read-ahead").
Revert closing the readahead to squashfs since the readahead callback for
squashfs is implemented.
Link: https://lkml.kernel.org/r/20220617083810.337573-1-hsinyi@chromium.org
Link: https://lkml.kernel.org/r/20220617083810.337573-2-hsinyi@chromium.org
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Suggested-by: Xiongwei Song <Xiongwei.Song@windriver.com>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Zheng Liang <zhengliang6@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Hou Tao <houtao1@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This is a "weak" conversion which converts straight back to using pages.
A full conversion should be performed at some point, hopefully by
someone familiar with the filesystem.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().
Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> [ext4]
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit c1f6925e10 ("mm: put readahead pages in cache earlier") causes
the read performance of squashfs to deteriorate.Through testing, we find
that the performance will be back by closing the readahead of squashfs.
So we want to learn the way of ubifs, provides backing_dev_info and
disable read-ahead
We tested the following data by fio.
squashfs image blocksize=128K
test command:
fio --name basic --bs=? --filename="/mnt/test_file" --rw=? --iodepth=1 --ioengine=psync --runtime=200 --time_based
turn on squashfs readahead in 5.10 kernel
bs(k) read/randread MB/s
4 randread 271
128 randread 231
1024 randread 246
4 read 310
128 read 245
1024 read 247
turn off squashfs readahead in 5.10 kernel
bs(k) read/randread MB/s
4 randread 293
128 randread 330
1024 randread 363
4 read 338
128 read 360
1024 read 365
turn on squashfs readahead and revert the
commit c1f6925e1091("mm: put readahead
pages in cache earlier") in 5.10 kernel
bs(k) read/randread MB/s
4 randread 289
128 randread 306
1024 randread 335
4 read 337
128 read 336
1024 read 338
Link: https://lkml.kernel.org/r/20211116113141.1391026-1-zhengliang6@huawei.com
Signed-off-by: Zheng Liang <zhengliang6@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Hou Tao <houtao1@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an errors=panic mount option to make squashfs trigger a panic when
errors are encountered, similar to several other filesystems. This allows
a kernel dump to be saved using which the corruption can be analysed and
debugged.
Inspired by a pre-fs_context patch by Anton Eliasson.
Link: https://lkml.kernel.org/r/20210527125019.14511-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sysbot has reported a number of "slab-out-of-bounds reads" and
"use-after-free read" errors which has been identified as being caused
by a corrupted index value read from the inode. This could be because
the metadata block is uncompressed, or because the "compression" bit has
been corrupted (turning a compressed block into an uncompressed block).
This patch adds additional sanity checks to detect this, and the
following corruption.
1. It checks against corruption of the ids count. This can either
lead to a larger table to be read, or a smaller than expected
table to be read.
In the case of a too large ids count, this would often have been
trapped by the existing sanity checks, but this patch introduces
a more exact check, which can identify too small values.
2. It checks the contents of the index table for corruption.
Link: https://lkml.kernel.org/r/20210204130249.4495-3-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: syzbot+b06d57ba83f604522af2@syzkaller.appspotmail.com
Reported-by: syzbot+c021ba012da41ee9807c@syzkaller.appspotmail.com
Reported-by: syzbot+5024636e8b5fd19f0f19@syzkaller.appspotmail.com
Reported-by: syzbot+bcbc661df46657d0fa4f@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull misc mount API conversions from Al Viro:
"Conversions to new API for shmem and friends and for mount_mtd()-using
filesystems.
As for the rest of the mount API conversions in -next, some of them
belong in the individual trees (e.g. binderfs one should definitely go
through android folks, after getting redone on top of their changes).
I'm going to drop those and send the rest (trivial ones + stuff ACKed
by maintainers) in a separate series - by that point they are
independent from each other.
Some stuff has already migrated into individual trees (NFS conversion,
for example, or FUSE stuff, etc.); those presumably will go through
the regular merges from corresponding trees."
* 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Make fs_parse() handle fs_param_is_fd-type params better
vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
shmem_parse_one(): switch to use of fs_parse()
shmem_parse_options(): take handling a single option into a helper
shmem_parse_options(): don't bother with mpol in separate variable
shmem_parse_options(): use a separate structure to keep the results
make shmem_fill_super() static
make ramfs_fill_super() static
devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
vfs: Convert squashfs to use the new mount API
mtd: Kill mount_mtd()
vfs: Convert jffs2 to use the new mount API
vfs: Convert cramfs to use the new mount API
vfs: Convert romfs to use the new mount API
vfs: Add a single-or-reconfig keying to vfs_get_super()
Convert the squashfs filesystem to the new internal mount API as the old
one will be obsoleted and removed. This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.
See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Phillip Lougher <phillip@squashfs.org.uk>
cc: squashfs-devel@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation 51 franklin street fifth
floor boston ma 02110 1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 23 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.458548087@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The squashfs fragment reading code doesn't actually verify that the
fragment is inside the fragment table. The end result _is_ verified to
be inside the image when actually reading the fragment data, but before
that is done, we may end up taking a page fault because the fragment
table itself might not even exist.
Another report from Anatoly and his endless squashfs image fuzzing.
Reported-by: Анатолий Тросиненко <anatoly.trosinenko@gmail.com>
Acked-by:: Phillip Lougher <phillip.lougher@gmail.com>,
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg. For the list, see below:
- threadinfo
- task_struct
- task_delay_info
- pid
- cred
- mm_struct
- vm_area_struct and vm_region (nommu)
- anon_vma and anon_vma_chain
- signal_struct
- sighand_struct
- fs_struct
- files_struct
- fdtable and fdtable->full_fds_bits
- dentry and external_name
- inode for all filesystems. This is the most tedious part, because
most filesystems overwrite the alloc_inode method.
The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds. Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The decompressor interface and code was written from
the point of view of single-threaded operation. In doing
so it mixed a lot of single-threaded implementation specific
aspects into the decompressor code and elsewhere which makes it
difficult to seamlessly support multiple different decompressor
implementations.
This patch does the following:
1. It removes compressor_options parsing from the decompressor
init() function. This allows the decompressor init() function
to be dynamically called to instantiate multiple decompressors,
without the compressor options needing to be read and parsed each
time.
2. It moves threading and all sleeping operations out of the
decompressors. In doing so, it makes the decompressors
non-blocking wrappers which only deal with interfacing with
the decompressor implementation.
3. It splits decompressor.[ch] into decompressor generic functions
in decompressor.[ch], and moves the single threaded
decompressor implementation into decompressor_single.c.
The result of this patch is Squashfs should now be able to
support multiple decompressors by adding new decompressor_xxx.c
files with specialised implementations of the functions in
decompressor_single.c
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Somehow I failed to add the MODULE_ALIAS_FS for cifs, hostfs, hpfs,
squashfs, and udf despite what I thought were my careful checks :(
Add them now.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There's no reason to call rcu_barrier() on every
deactivate_locked_super(). We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.
Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths. E.g. on my machine exit_group() of a last process in IPC
namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
Pull squashfs updates from Phillip Lougher:
"Add an extra mount time sanity check, plus some code cleanups and bug
fixes."
* tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
Squashfs: add mount time sanity check for block_size and block_log match
Squashfs: fix f_pos check in get_dir_index_using_offset
Squashfs: get rid of obsolete definitions in header file
Squashfs: remove redundant length initialisation in squashfs_lookup
Squashfs: remove redundant length initialisation in squashfs_readdir
Squashfs: update comment removing reference to zlib only
Squashfs: use define instead of constant
Squashfs currently has a sanity check for block_size less than or
equal to the maximum block_size (1 Mbyte). This catches some
superblock corruption, but obviously with a block_size maximum
of 1 Mbyte there's 7 correct values (4K, 8K, 16K, 32K, ... etc) and
a lot of incorrect values which are not caught by this check.
The Squashfs superblock, however, has both a block_size and
a block_log (2^block_log == block_size). Checking that the block_size
matches the block_log is a much more robust check. Corruption of the
superblock is unlikely to produce values which match, and it also
ensures the block_size is an exact power of two.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A Squashfs filesystem containing nothing but an empty directory,
although unusual and ultimately pointless, is still valid.
The directory_table >= next_table sanity check rejects these
filesystems as invalid because the directory_table is empty and
equal to next_table.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
This commit adds an option to set the device block size used to 4K.
By default Squashfs sets the device block size (sb_min_blocksize) to 1K
or the smallest block size supported by the block device (if larger).
This, because blocks are packed together and unaligned in Squashfs,
should reduce latency.
This, however, gives poor performance on MTD NAND devices where
the optimal I/O size is 4K (even though the devices can support
smaller block sizes).
Using a 4K device block size may also improve overall I/O
performance for some file access patterns (e.g. sequential
accesses of files in filesystem order) on all media.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
My existing email address may stop working in a month or two, so update
email to one that will continue working.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock fragments field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time fragment table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock inodes field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time lookup table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock no_ids field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time id table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Reverse order of table reading from mostly first to last in placement
order, to last to first. This is to enable extra superblock sanity
checks to be added in later patches.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Squashfs_get_sb() to squashfs_mount() conversion (commit 152a0836)
results in line over 80 characters.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Extend decompressor framework to handle compression options stored in
the filesystem. These options can be used by the relevant decompressor
at initialisation time to over-ride defaults.
The presence of compression options in the filesystem is indicated by
the COMP_OPT filesystem flag. If present the data is read from the
filesystem and passed to the decompressor init function. The decompressor
init function signature has been extended to take this data.
Also update the init function signature in the glib, lzo and xz
decompressor wrappers.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The BKL is only used in put_super and fill_super, which are both protected
by the superblocks s_umount rw_semaphore. Therefore it is safe to remove
the BKL entirely.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.
I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.
Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.
[arnd: do not add the BKL to those file systems that already
don't use it elsewhere]
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
