To use the new rwsem_assert_held()/rwsem_assert_held_write(), we can't
use the existing ASSERT macro. Add a new xfs_assert_ilocked() and
convert all the callers.
Fix an apparent bug in xfs_isilocked(): If the caller specifies
XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL, xfs_assert_ilocked() will check both
the IOLOCK and the ILOCK are held for write. xfs_isilocked() only
checked that the ILOCK was held for write.
xfs_assert_ilocked() is always on, even if DEBUG or XFS_WARN aren't
defined. It's a cheap check, so I don't think it's worth defining
it away.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Start getting rid of kmem_free() by converting all the cases where
memory can come from vmalloc interfaces to calling kvfree()
directly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The xfs_ifork structure currently has a union of the if_root void pointer
and the if_data char pointer. In either case it is an opaque pointer
that depends on the fork format. Replace the union with a single if_data
void pointer as that is what almost all callers want. Only the symlink
NULL termination code in xfs_init_local_fork actually needs a new local
variable now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Alexander Potapenko report that KMSAN was issuing these warnings:
kmalloc-ed xlog buffer of size 512 : ffff88802fc26200
kmalloc-ed xlog buffer of size 368 : ffff88802fc24a00
kmalloc-ed xlog buffer of size 648 : ffff88802b631000
kmalloc-ed xlog buffer of size 648 : ffff88802b632800
kmalloc-ed xlog buffer of size 648 : ffff88802b631c00
xlog_write_iovec: copying 12 bytes from ffff888017ddbbd8 to ffff88802c300400
xlog_write_iovec: copying 28 bytes from ffff888017ddbbe4 to ffff88802c30040c
xlog_write_iovec: copying 68 bytes from ffff88802fc26274 to ffff88802c300428
xlog_write_iovec: copying 188 bytes from ffff88802fc262bc to ffff88802c30046c
=====================================================
BUG: KMSAN: uninit-value in xlog_write_iovec fs/xfs/xfs_log.c:2227
BUG: KMSAN: uninit-value in xlog_write_full fs/xfs/xfs_log.c:2263
BUG: KMSAN: uninit-value in xlog_write+0x1fac/0x2600 fs/xfs/xfs_log.c:2532
xlog_write_iovec fs/xfs/xfs_log.c:2227
xlog_write_full fs/xfs/xfs_log.c:2263
xlog_write+0x1fac/0x2600 fs/xfs/xfs_log.c:2532
xlog_cil_write_chain fs/xfs/xfs_log_cil.c:918
xlog_cil_push_work+0x30f2/0x44e0 fs/xfs/xfs_log_cil.c:1263
process_one_work kernel/workqueue.c:2630
process_scheduled_works+0x1188/0x1e30 kernel/workqueue.c:2703
worker_thread+0xee5/0x14f0 kernel/workqueue.c:2784
kthread+0x391/0x500 kernel/kthread.c:388
ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
Uninit was created at:
slab_post_alloc_hook+0x101/0xac0 mm/slab.h:768
slab_alloc_node mm/slub.c:3482
__kmem_cache_alloc_node+0x612/0xae0 mm/slub.c:3521
__do_kmalloc_node mm/slab_common.c:1006
__kmalloc+0x11a/0x410 mm/slab_common.c:1020
kmalloc ./include/linux/slab.h:604
xlog_kvmalloc fs/xfs/xfs_log_priv.h:704
xlog_cil_alloc_shadow_bufs fs/xfs/xfs_log_cil.c:343
xlog_cil_commit+0x487/0x4dc0 fs/xfs/xfs_log_cil.c:1574
__xfs_trans_commit+0x8df/0x1930 fs/xfs/xfs_trans.c:1017
xfs_trans_commit+0x30/0x40 fs/xfs/xfs_trans.c:1061
xfs_create+0x15af/0x2150 fs/xfs/xfs_inode.c:1076
xfs_generic_create+0x4cd/0x1550 fs/xfs/xfs_iops.c:199
xfs_vn_create+0x4a/0x60 fs/xfs/xfs_iops.c:275
lookup_open fs/namei.c:3477
open_last_lookups fs/namei.c:3546
path_openat+0x29ac/0x6180 fs/namei.c:3776
do_filp_open+0x24d/0x680 fs/namei.c:3809
do_sys_openat2+0x1bc/0x330 fs/open.c:1440
do_sys_open fs/open.c:1455
__do_sys_openat fs/open.c:1471
__se_sys_openat fs/open.c:1466
__x64_sys_openat+0x253/0x330 fs/open.c:1466
do_syscall_x64 arch/x86/entry/common.c:51
do_syscall_64+0x4f/0x140 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b arch/x86/entry/entry_64.S:120
Bytes 112-115 of 188 are uninitialized
Memory access of size 188 starts at ffff88802fc262bc
This is caused by the struct xfs_log_dinode not having the di_crc
field initialised. Log recovery never uses this field (it is only
present these days for on-disk format compatibility reasons) and so
it's value is never checked so nothing in XFS has caught this.
Further, none of the uninitialised memory access warning tools have
caught this (despite catching other uninit memory accesses in the
struct xfs_log_dinode back in 2017!) until recently. Alexander
annotated the XFS code to get the dump of the actual bytes that were
detected as uninitialised, and from that report it took me about 30s
to realise what the issue was.
The issue was introduced back in 2016 and every inode that is logged
fails to initialise this field. This is no actual bad behaviour
caused by this issue - I find it hard to even classify it as a
bug...
Reported-and-tested-by: Alexander Potapenko <glider@google.com>
Fixes: f8d55aa052 ("xfs: introduce inode log format object")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* Realtime device subsystem
- Cleanup usage of xfs_rtblock_t and xfs_fsblock_t data types.
- Replace open coded conversions between rt blocks and rt extents with
calls to static inline helpers.
- Replace open coded realtime geometry compuation and macros with helper
functions.
- CPU usage optimizations for realtime allocator.
- Misc. Bug fixes associated with Realtime device.
* Allow read operations to execute while an FICLONE ioctl is being serviced.
* Misc. bug fixes
- Alert user when xfs_droplink() encounters an inode with a link count of zero.
- Handle the case where the allocator could return zero extents when
servicing an fallocate request.
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.7-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Chandan Babu:
- Realtime device subsystem:
- Cleanup usage of xfs_rtblock_t and xfs_fsblock_t data types
- Replace open coded conversions between rt blocks and rt extents
with calls to static inline helpers
- Replace open coded realtime geometry compuation and macros with
helper functions
- CPU usage optimizations for realtime allocator
- Misc bug fixes associated with Realtime device
- Allow read operations to execute while an FICLONE ioctl is being
serviced
- Misc bug fixes:
- Alert user when xfs_droplink() encounters an inode with a link
count of zero
- Handle the case where the allocator could return zero extents when
servicing an fallocate request
* tag 'xfs-6.7-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (40 commits)
xfs: allow read IO and FICLONE to run concurrently
xfs: handle nimaps=0 from xfs_bmapi_write in xfs_alloc_file_space
xfs: introduce protection for drop nlink
xfs: don't look for end of extent further than necessary in xfs_rtallocate_extent_near()
xfs: don't try redundant allocations in xfs_rtallocate_extent_near()
xfs: limit maxlen based on available space in xfs_rtallocate_extent_near()
xfs: return maximum free size from xfs_rtany_summary()
xfs: invert the realtime summary cache
xfs: simplify rt bitmap/summary block accessor functions
xfs: simplify xfs_rtbuf_get calling conventions
xfs: cache last bitmap block in realtime allocator
xfs: use accessor functions for summary info words
xfs: consolidate realtime allocation arguments
xfs: create helpers for rtsummary block/wordcount computations
xfs: use accessor functions for bitmap words
xfs: create helpers for rtbitmap block/wordcount computations
xfs: create a helper to handle logging parts of rt bitmap/summary blocks
xfs: convert rt summary macros to helpers
xfs: convert open-coded xfs_rtword_t pointer accesses to helper
xfs: remove XFS_BLOCKWSIZE and XFS_BLOCKWMASK macros
...
Create a helper to compute the misalignment between a file extent
(xfs_extlen_t) and a realtime extent.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-80-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Lock order in XFS is AGI -> AGF, hence for operations involving
inode unlinked list operations we always lock the AGI first. Inode
unlinked list operations operate on the inode cluster buffer,
so the lock order there is AGI -> inode cluster buffer.
For O_TMPFILE operations, this now means the lock order set down in
xfs_rename and xfs_link is AGI -> inode cluster buffer -> AGF as the
unlinked ops are done before the directory modifications that may
allocate space and lock the AGF.
Unfortunately, we also now lock the inode cluster buffer when
logging an inode so that we can attach the inode to the cluster
buffer and pin it in memory. This creates a lock order of AGF ->
inode cluster buffer in directory operations as we have to log the
inode after we've allocated new space for it.
This creates a lock inversion between the AGF and the inode cluster
buffer. Because the inode cluster buffer is shared across multiple
inodes, the inversion is not specific to individual inodes but can
occur when inodes in the same cluster buffer are accessed in
different orders.
To fix this we need move all the inode log item cluster buffer
interactions to the end of the current transaction. Unfortunately,
xfs_trans_log_inode() calls are littered throughout the transactions
with no thought to ordering against other items or locking. This
makes it difficult to do anything that involves changing the call
sites of xfs_trans_log_inode() to change locking orders.
However, we do now have a mechanism that allows is to postpone dirty
item processing to just before we commit the transaction: the
->iop_precommit method. This will be called after all the
modifications are done and high level objects like AGI and AGF
buffers have been locked and modified, thereby providing a mechanism
that guarantees we don't lock the inode cluster buffer before those
high level objects are locked.
This change is largely moving the guts of xfs_trans_log_inode() to
xfs_inode_item_precommit() and providing an extra flag context in
the inode log item to track the dirty state of the inode in the
current transaction. This also means we do a lot less repeated work
in xfs_trans_log_inode() by only doing it once per transaction when
all the work is done.
Fixes: 298f7bec50 ("xfs: pin inode backing buffer to the inode log item")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Just remove the redundant word "being" in comment.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Replace the shouty macros here with typechecked helper functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Replace this shouty macro with a real C function that has a more
descriptive name.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Syzkaller reported a UAF bug a while back:
==================================================================
BUG: KASAN: use-after-free in xfs_ilock_attr_map_shared+0xe3/0xf6 fs/xfs/xfs_inode.c:127
Read of size 4 at addr ffff88802cec919c by task syz-executor262/2958
CPU: 2 PID: 2958 Comm: syz-executor262 Not tainted
5.15.0-0.30.3-20220406_1406 #3
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29
04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x82/0xa9 lib/dump_stack.c:106
print_address_description.constprop.9+0x21/0x2d5 mm/kasan/report.c:256
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold.14+0x7f/0x11b mm/kasan/report.c:459
xfs_ilock_attr_map_shared+0xe3/0xf6 fs/xfs/xfs_inode.c:127
xfs_attr_get+0x378/0x4c2 fs/xfs/libxfs/xfs_attr.c:159
xfs_xattr_get+0xe3/0x150 fs/xfs/xfs_xattr.c:36
__vfs_getxattr+0xdf/0x13d fs/xattr.c:399
cap_inode_need_killpriv+0x41/0x5d security/commoncap.c:300
security_inode_need_killpriv+0x4c/0x97 security/security.c:1408
dentry_needs_remove_privs.part.28+0x21/0x63 fs/inode.c:1912
dentry_needs_remove_privs+0x80/0x9e fs/inode.c:1908
do_truncate+0xc3/0x1e0 fs/open.c:56
handle_truncate fs/namei.c:3084 [inline]
do_open fs/namei.c:3432 [inline]
path_openat+0x30ab/0x396d fs/namei.c:3561
do_filp_open+0x1c4/0x290 fs/namei.c:3588
do_sys_openat2+0x60d/0x98c fs/open.c:1212
do_sys_open+0xcf/0x13c fs/open.c:1228
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0x0
RIP: 0033:0x7f7ef4bb753d
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48
89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73
01 c3 48 8b 0d 1b 79 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007f7ef52c2ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000404148 RCX: 00007f7ef4bb753d
RDX: 00007f7ef4bb753d RSI: 0000000000000000 RDI: 0000000020004fc0
RBP: 0000000000404140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007ffd794db37f R14: 00007ffd794db470 R15: 00007f7ef52c2fc0
</TASK>
Allocated by task 2953:
kasan_save_stack+0x19/0x38 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x68/0x7c mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3213 [inline]
slab_alloc mm/slub.c:3221 [inline]
kmem_cache_alloc+0x11b/0x3eb mm/slub.c:3226
kmem_cache_zalloc include/linux/slab.h:711 [inline]
xfs_ifork_alloc+0x25/0xa2 fs/xfs/libxfs/xfs_inode_fork.c:287
xfs_bmap_add_attrfork+0x3f2/0x9b1 fs/xfs/libxfs/xfs_bmap.c:1098
xfs_attr_set+0xe38/0x12a7 fs/xfs/libxfs/xfs_attr.c:746
xfs_xattr_set+0xeb/0x1a9 fs/xfs/xfs_xattr.c:59
__vfs_setxattr+0x11b/0x177 fs/xattr.c:180
__vfs_setxattr_noperm+0x128/0x5e0 fs/xattr.c:214
__vfs_setxattr_locked+0x1d4/0x258 fs/xattr.c:275
vfs_setxattr+0x154/0x33d fs/xattr.c:301
setxattr+0x216/0x29f fs/xattr.c:575
__do_sys_fsetxattr fs/xattr.c:632 [inline]
__se_sys_fsetxattr fs/xattr.c:621 [inline]
__x64_sys_fsetxattr+0x243/0x2fe fs/xattr.c:621
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0x0
Freed by task 2949:
kasan_save_stack+0x19/0x38 mm/kasan/common.c:38
kasan_set_track+0x1c/0x21 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xe2/0x10e mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1700 [inline]
slab_free_freelist_hook mm/slub.c:1726 [inline]
slab_free mm/slub.c:3492 [inline]
kmem_cache_free+0xdc/0x3ce mm/slub.c:3508
xfs_attr_fork_remove+0x8d/0x132 fs/xfs/libxfs/xfs_attr_leaf.c:773
xfs_attr_sf_removename+0x5dd/0x6cb fs/xfs/libxfs/xfs_attr_leaf.c:822
xfs_attr_remove_iter+0x68c/0x805 fs/xfs/libxfs/xfs_attr.c:1413
xfs_attr_remove_args+0xb1/0x10d fs/xfs/libxfs/xfs_attr.c:684
xfs_attr_set+0xf1e/0x12a7 fs/xfs/libxfs/xfs_attr.c:802
xfs_xattr_set+0xeb/0x1a9 fs/xfs/xfs_xattr.c:59
__vfs_removexattr+0x106/0x16a fs/xattr.c:468
cap_inode_killpriv+0x24/0x47 security/commoncap.c:324
security_inode_killpriv+0x54/0xa1 security/security.c:1414
setattr_prepare+0x1a6/0x897 fs/attr.c:146
xfs_vn_change_ok+0x111/0x15e fs/xfs/xfs_iops.c:682
xfs_vn_setattr_size+0x5f/0x15a fs/xfs/xfs_iops.c:1065
xfs_vn_setattr+0x125/0x2ad fs/xfs/xfs_iops.c:1093
notify_change+0xae5/0x10a1 fs/attr.c:410
do_truncate+0x134/0x1e0 fs/open.c:64
handle_truncate fs/namei.c:3084 [inline]
do_open fs/namei.c:3432 [inline]
path_openat+0x30ab/0x396d fs/namei.c:3561
do_filp_open+0x1c4/0x290 fs/namei.c:3588
do_sys_openat2+0x60d/0x98c fs/open.c:1212
do_sys_open+0xcf/0x13c fs/open.c:1228
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0x0
The buggy address belongs to the object at ffff88802cec9188
which belongs to the cache xfs_ifork of size 40
The buggy address is located 20 bytes inside of
40-byte region [ffff88802cec9188, ffff88802cec91b0)
The buggy address belongs to the page:
page:00000000c3af36a1 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x2cec9
flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000200 ffffea00009d2580 0000000600000006 ffff88801a9ffc80
raw: 0000000000000000 0000000080490049 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88802cec9080: fb fb fb fc fc fa fb fb fb fb fc fc fb fb fb fb
ffff88802cec9100: fb fc fc fb fb fb fb fb fc fc fb fb fb fb fb fc
>ffff88802cec9180: fc fa fb fb fb fb fc fc fa fb fb fb fb fc fc fb
^
ffff88802cec9200: fb fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb
ffff88802cec9280: fb fb fc fc fa fb fb fb fb fc fc fa fb fb fb fb
==================================================================
The root cause of this bug is the unlocked access to xfs_inode.i_afp
from the getxattr code paths while trying to determine which ILOCK mode
to use to stabilize the xattr data. Unfortunately, the VFS does not
acquire i_rwsem when vfs_getxattr (or listxattr) call into the
filesystem, which means that getxattr can race with a removexattr that's
tearing down the attr fork and crash:
xfs_attr_set: xfs_attr_get:
xfs_attr_fork_remove: xfs_ilock_attr_map_shared:
xfs_idestroy_fork(ip->i_afp);
kmem_cache_free(xfs_ifork_cache, ip->i_afp);
if (ip->i_afp &&
ip->i_afp = NULL;
xfs_need_iread_extents(ip->i_afp))
<KABOOM>
ip->i_forkoff = 0;
Regrettably, the VFS is much more lax about i_rwsem and getxattr than
is immediately obvious -- not only does it not guarantee that we hold
i_rwsem, it actually doesn't guarantee that we *don't* hold it either.
The getxattr system call won't acquire the lock before calling XFS, but
the file capabilities code calls getxattr with and without i_rwsem held
to determine if the "security.capabilities" xattr is set on the file.
Fixing the VFS locking requires a treewide investigation into every code
path that could touch an xattr and what i_rwsem state it expects or sets
up. That could take years or even prove impossible; fortunately, we
can fix this UAF problem inside XFS.
An earlier version of this patch used smp_wmb in xfs_attr_fork_remove to
ensure that i_forkoff is always zeroed before i_afp is set to null and
changed the read paths to use smp_rmb before accessing i_forkoff and
i_afp, which avoided these UAF problems. However, the patch author was
too busy dealing with other problems in the meantime, and by the time he
came back to this issue, the situation had changed a bit.
On a modern system with selinux, each inode will always have at least
one xattr for the selinux label, so it doesn't make much sense to keep
incurring the extra pointer dereference. Furthermore, Allison's
upcoming parent pointer patchset will also cause nearly every inode in
the filesystem to have extended attributes. Therefore, make the inode
attribute fork structure part of struct xfs_inode, at a cost of 40 more
bytes.
This patch adds a clunky if_present field where necessary to maintain
the existing logic of xattr fork null pointer testing in the existing
codebase. The next patch switches the logic over to XFS_IFORK_Q and it
all goes away.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Callers currently have to round out the size of buffers to match the
aligment constraints of log iovecs and xlog_write(). They should not
need to know this detail, so introduce a new function to calculate
the iovec length (for use in ->iop_size implementations). Also
modify xlog_finish_iovec() to round up the length to the correct
alignment so the callers don't need to do this, either.
Convert the only user - inode forks - of this alignment rounding to
use the new interface.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit introduces new fields in the on-disk inode format to support
64-bit data fork extent counters and 32-bit attribute fork extent
counters. The new fields will be used only when an inode has
XFS_DIFLAG2_NREXT64 flag set. Otherwise we continue to use the regular 32-bit
data fork extent counters and 16-bit attribute fork extent counters.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Suggested-by: Dave Chinner <dchinner@redhat.com>
Most buffer io list operations are run with the bp->b_lock held, but
xfs_iflush_abort() can be called without the buffer lock being held
resulting in inodes being removed from the buffer list while other
list operations are occurring. This causes problems with corrupted
bp->b_io_list inode lists during filesystem shutdown, leading to
traversals that never end, double removals from the AIL, etc.
Fix this by passing the buffer to xfs_iflush_abort() if we have
it locked. If the inode is attached to the buffer, we're going to
have to remove it from the buffer list and we'd have to get the
buffer off the inode log item to do that anyway.
If we don't have a buffer passed in (e.g. from xfs_reclaim_inode())
then we can determine if the inode has a log item and if it is
attached to a buffer before we do anything else. If it does have an
attached buffer, we can lock it safely (because the inode has a
reference to it) and then perform the inode abort.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
I've been chasing a recent resurgence in generic/388 recovery
failure and/or corruption events. The events have largely been
uninitialised inode chunks being tripped over in log recovery
such as:
XFS (pmem1): User initiated shutdown received.
pmem1: writeback error on inode 12621949, offset 1019904, sector 12968096
XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/xfs/xfs_fsops.c:500). Shutting down filesystem.
XFS (pmem1): Please unmount the filesystem and rectify the problem(s)
XFS (pmem1): Unmounting Filesystem
XFS (pmem1): Mounting V5 Filesystem
XFS (pmem1): Starting recovery (logdev: internal)
XFS (pmem1): bad inode magic/vsn daddr 8723584 #0 (magic=1818)
XFS (pmem1): Metadata corruption detected at xfs_inode_buf_verify+0x180/0x190, xfs_inode block 0x851c80 xfs_inode_buf_verify
XFS (pmem1): Unmount and run xfs_repair
XFS (pmem1): First 128 bytes of corrupted metadata buffer:
00000000: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000010: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000020: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000030: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000040: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000050: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000060: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
00000070: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 ................
XFS (pmem1): metadata I/O error in "xlog_recover_items_pass2+0x52/0xc0" at daddr 0x851c80 len 32 error 117
XFS (pmem1): log mount/recovery failed: error -117
XFS (pmem1): log mount failed
There have been isolated random other issues, too - xfs_repair fails
because it finds some corruption in symlink blocks, rmap
inconsistencies, etc - but they are nowhere near as common as the
uninitialised inode chunk failure.
The problem has clearly happened at runtime before recovery has run;
I can see the ICREATE log item in the log shortly before the
actively recovered range of the log. This means the ICREATE was
definitely created and written to the log, but for some reason the
tail of the log has been moved past the ordered buffer log item that
tracks INODE_ALLOC buffers and, supposedly, prevents the tail of the
log moving past the ICREATE log item before the inode chunk buffer
is written to disk.
Tracing the fsstress processes that are running when the filesystem
shut down immediately pin-pointed the problem:
user shutdown marks xfs_mount as shutdown
godown-213341 [008] 6398.022871: console: [ 6397.915392] XFS (pmem1): User initiated shutdown received.
.....
aild tries to push ordered inode cluster buffer
xfsaild/pmem1-213314 [001] 6398.022974: xfs_buf_trylock: dev 259:1 daddr 0x851c80 bbcount 0x20 hold 16 pincount 0 lock 0 flags DONE|INODES|PAGES caller xfs_inode_item_push+0x8e
xfsaild/pmem1-213314 [001] 6398.022976: xfs_ilock_nowait: dev 259:1 ino 0x851c80 flags ILOCK_SHARED caller xfs_iflush_cluster+0xae
xfs_iflush_cluster() checks xfs_is_shutdown(), returns true,
calls xfs_iflush_abort() to kill writeback of the inode.
Inode is removed from AIL, drops cluster buffer reference.
xfsaild/pmem1-213314 [001] 6398.022977: xfs_ail_delete: dev 259:1 lip 0xffff88880247ed80 old lsn 7/20344 new lsn 7/21000 type XFS_LI_INODE flags IN_AIL
xfsaild/pmem1-213314 [001] 6398.022978: xfs_buf_rele: dev 259:1 daddr 0x851c80 bbcount 0x20 hold 17 pincount 0 lock 0 flags DONE|INODES|PAGES caller xfs_iflush_abort+0xd7
.....
All inodes on cluster buffer are aborted, then the cluster buffer
itself is aborted and removed from the AIL *without writeback*:
xfsaild/pmem1-213314 [001] 6398.023011: xfs_buf_error_relse: dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_ioend_fail+0x33
xfsaild/pmem1-213314 [001] 6398.023012: xfs_ail_delete: dev 259:1 lip 0xffff8888053efde8 old lsn 7/20344 new lsn 7/20344 type XFS_LI_BUF flags IN_AIL
The inode buffer was at 7/20344 when it was removed from the AIL.
xfsaild/pmem1-213314 [001] 6398.023012: xfs_buf_item_relse: dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_item_done+0x31
xfsaild/pmem1-213314 [001] 6398.023012: xfs_buf_rele: dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_item_relse+0x39
.....
Userspace is still running, doing stuff. an fsstress process runs
syncfs() or sync() and we end up in sync_fs_one_sb() which issues
a log force. This pushes on the CIL:
fsstress-213322 [001] 6398.024430: xfs_fs_sync_fs: dev 259:1 m_features 0x20000000019ff6e9 opstate (clean|shutdown|inodegc|blockgc) s_flags 0x70810000 caller sync_fs_one_sb+0x26
fsstress-213322 [001] 6398.024430: xfs_log_force: dev 259:1 lsn 0x0 caller xfs_fs_sync_fs+0x82
fsstress-213322 [001] 6398.024430: xfs_log_force: dev 259:1 lsn 0x5f caller xfs_log_force+0x7c
<...>-194402 [001] 6398.024467: kmem_alloc: size 176 flags 0x14 caller xlog_cil_push_work+0x9f
And the CIL fills up iclogs with pending changes. This picks up
the current tail from the AIL:
<...>-194402 [001] 6398.024497: xlog_iclog_get_space: dev 259:1 state XLOG_STATE_ACTIVE refcnt 1 offset 0 lsn 0x0 flags caller xlog_write+0x149
<...>-194402 [001] 6398.024498: xlog_iclog_switch: dev 259:1 state XLOG_STATE_ACTIVE refcnt 1 offset 0 lsn 0x700005408 flags caller xlog_state_get_iclog_space+0x37e
<...>-194402 [001] 6398.024521: xlog_iclog_release: dev 259:1 state XLOG_STATE_WANT_SYNC refcnt 1 offset 32256 lsn 0x700005408 flags caller xlog_write+0x5f9
<...>-194402 [001] 6398.024522: xfs_log_assign_tail_lsn: dev 259:1 new tail lsn 7/21000, old lsn 7/20344, last sync 7/21448
And it moves the tail of the log to 7/21000 from 7/20344. This
*moves the tail of the log beyond the ICREATE transaction* that was
at 7/20344 and pinned by the inode cluster buffer that was cancelled
above.
....
godown-213341 [008] 6398.027005: xfs_force_shutdown: dev 259:1 tag logerror flags log_io|force_umount file fs/xfs/xfs_fsops.c line_num 500
godown-213341 [008] 6398.027022: console: [ 6397.915406] pmem1: writeback error on inode 12621949, offset 1019904, sector 12968096
godown-213341 [008] 6398.030551: console: [ 6397.919546] XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/
And finally the log itself is now shutdown, stopping all further
writes to the log. But this is too late to prevent the corruption
that moving the tail of the log forwards after we start cancelling
writeback causes.
The fundamental problem here is that we are using the wrong shutdown
checks for log items. We've long conflated mount shutdown with log
shutdown state, and I started separating that recently with the
atomic shutdown state changes in commit b36d4651e1 ("xfs: make
forced shutdown processing atomic"). The changes in that commit
series are directly responsible for being able to diagnose this
issue because it clearly separated mount shutdown from log shutdown.
Essentially, once we start cancelling writeback of log items and
removing them from the AIL because the filesystem is shut down, we
*cannot* update the journal because we may have cancelled the items
that pin the tail of the log. That moves the tail of the log
forwards without having written the metadata back, hence we have
corrupt in memory state and writing to the journal propagates that
to the on-disk state.
What commit b36d4651e1 makes clear is that log item state needs to
change relative to log shutdown, not mount shutdown. IOWs, anything
that aborts metadata writeback needs to check log shutdown state
because log items directly affect log consistency. Having them check
mount shutdown state introduces the above race condition where we
cancel metadata writeback before the log shuts down.
To fix this, this patch works through all log items and converts
shutdown checks to use xlog_is_shutdown() rather than
xfs_is_shutdown(), so that we don't start aborting metadata
writeback before we shut off journal writes.
AFAICT, this race condition is a zero day IO error handling bug in
XFS that dates back to the introduction of XLOG_IO_ERROR,
XLOG_STATE_IOERROR and XFS_FORCED_SHUTDOWN back in January 1997.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Now that we've gotten rid of the kmem_zone_t typedef, rename the
variables to _cache since that's what they are.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Remove these typedefs by referencing kmem_cache directly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Convert the xfs_sb_version_hasfoo() to checks against
mp->m_features. Checks of the superblock itself during disk
operations (e.g. in the read/write verifiers and the to/from disk
formatters) are not converted - they operate purely on the
superblock state. Everything else should use the mount features.
Large parts of this conversion were done with sed with commands like
this:
for f in `git grep -l xfs_sb_version_has fs/xfs/*.c`; do
sed -i -e 's/xfs_sb_version_has\(.*\)(&\(.*\)->m_sb)/xfs_has_\1(\2)/' $f
done
With manual cleanups for things like "xfs_has_extflgbit" and other
little inconsistencies in naming.
The result is ia lot less typing to check features and an XFS binary
size reduced by a bit over 3kB:
$ size -t fs/xfs/built-in.a
text data bss dec hex filenam
before 1130866 311352 484 1442702 16038e (TOTALS)
after 1127727 311352 484 1439563 15f74b (TOTALS)
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In doing an investigation into AIL push stalls, I was looking at the
log force code to see if an async CIL push could be done instead.
This lead me to xfs_log_force_lsn() and looking at how it works.
xfs_log_force_lsn() is only called from inode synchronisation
contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn
value as the LSN to sync the log to. This gets passed to
xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the
journal, and then used by xfs_log_force_lsn() to flush the iclogs to
the journal.
The problem is that ip->i_itemp->ili_last_lsn does not store a
log sequence number. What it stores is passed to it from the
->iop_committing method, which is called by xfs_log_commit_cil().
The value this passes to the iop_committing method is the CIL
context sequence number that the item was committed to.
As it turns out, xlog_cil_force_lsn() converts the sequence to an
actual commit LSN for the related context and returns that to
xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn"
variable that contained a sequence with an actual LSN and then uses
that to sync the iclogs.
This caused me some confusion for a while, even though I originally
wrote all this code a decade ago. ->iop_committing is only used by
a couple of log item types, and only inode items use the sequence
number it is passed.
Let's clean up the API, CIL structures and inode log item to call it
a sequence number, and make it clear that the high level code is
using CIL sequence numbers and not on-disk LSNs for integrity
synchronisation purposes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
A hang with tasks stuck on the CIL hard throttle was reported and
largely diagnosed by Donald Buczek, who discovered that it was a
result of the CIL context space usage decrementing in committed
transactions once the hard throttle limit had been hit and processes
were already blocked. This resulted in the CIL push not waking up
those waiters because the CIL context was no longer over the hard
throttle limit.
The surprising aspect of this was the CIL space usage going
backwards regularly enough to trigger this situation. Assumptions
had been made in design that the relogging process would only
increase the size of the objects in the CIL, and so that space would
only increase.
This change and commit message fixes the issue and documents the
result of an audit of the triggers that can cause the CIL space to
go backwards, how large the backwards steps tend to be, the
frequency in which they occur, and what the impact on the CIL
accounting code is.
Even though the CIL ctx->space_used can go backwards, it will only
do so if the log item is already logged to the CIL and contains a
space reservation for it's entire logged state. This is tracked by
the shadow buffer state on the log item. If the item is not
previously logged in the CIL it has no shadow buffer nor log vector,
and hence the entire size of the logged item copied to the log
vector is accounted to the CIL space usage. i.e. it will always go
up in this case.
If the item has a log vector (i.e. already in the CIL) and the size
decreases, then the existing log vector will be overwritten and the
space usage will go down. This is the only condition where the space
usage reduces, and it can only occur when an item is already tracked
in the CIL. Hence we are safe from CIL space usage underruns as a
result of log items decreasing in size when they are relogged.
Typically this reduction in CIL usage occurs from metadata blocks
being free, such as when a btree block merge occurs or a directory
enter/xattr entry is removed and the da-tree is reduced in size.
This generally results in a reduction in size of around a single
block in the CIL, but also tends to increase the number of log
vectors because the parent and sibling nodes in the tree needs to be
updated when a btree block is removed. If a multi-level merge
occurs, then we see reduction in size of 2+ blocks, but again the
log vector count goes up.
The other vector is inode fork size changes, which only log the
current size of the fork and ignore the previously logged size when
the fork is relogged. Hence if we are removing items from the inode
fork (dir/xattr removal in shortform, extent record removal in
extent form, etc) the relogged size of the inode for can decrease.
No other log items can decrease in size either because they are a
fixed size (e.g. dquots) or they cannot be relogged (e.g. relogging
an intent actually creates a new intent log item and doesn't relog
the old item at all.) Hence the only two vectors for CIL context
size reduction are relogging inode forks and marking buffers active
in the CIL as stale.
Long story short: the majority of the code does the right thing and
handles the reduction in log item size correctly, and only the CIL
hard throttle implementation is problematic and needs fixing. This
patch makes that fix, as well as adds comments in the log item code
that result in items shrinking in size when they are relogged as a
clear reminder that this can and does happen frequently.
The throttle fix is based upon the change Donald proposed, though it
goes further to ensure that once the throttle is activated, it
captures all tasks until the CIL push issues a wakeup, regardless of
whether the CIL space used has gone back under the throttle
threshold.
This ensures that we prevent tasks reducing the CIL slightly under
the throttle threshold and then making more changes that push it
well over the throttle limit. This is acheived by checking if the
throttle wait queue is already active as a condition of throttling.
Hence once we start throttling, we continue to apply the throttle
until the CIL context push wakes everything on the wait queue.
We can use waitqueue_active() for the waitqueue manipulations and
checks as they are all done under the ctx->xc_push_lock. Hence the
waitqueue has external serialisation and we can safely peek inside
the wait queue without holding the internal waitqueue locks.
Many thanks to Donald for his diagnostic and analysis work to
isolate the cause of this hang.
Reported-and-tested-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Rename struct xfs_legacy_ictimestamp to struct xfs_log_legacy_timestamp
as it is a type used for logging timestamps with no relationship to the
in-core inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Rename xfs_ictimestamp_t to xfs_log_timestamp_t as it is a type used
for logging timestamps with no relationship to the in-core inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Move the crtime field from struct xfs_icdinode into stuct xfs_inode and
remove the now entirely unused struct xfs_icdinode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the flags2
field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the flags
field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the
forkoff field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the
flushiter field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the
cowextsize field into the containing xfs_inode structure. Also
switch to use the xfs_extlen_t instead of a uint32_t.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the extsize
field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the nblocks
field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the on-disk
size field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In preparation of removing the historic icinode struct, move the projid
field into the containing xfs_inode structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The legacy DMAPI fields were never set by upstream Linux XFS, and have no
way to be read using the kernel APIs. So instead of bloating the in-core
inode for them just copy them from the on-disk inode into the log when
logging the inode. The only caveat is that we need to make sure to zero
the fields for newly read or deleted inodes, which is solved using a new
flag in the inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Redesign the ondisk inode timestamps to be a simple unsigned 64-bit
counter of nanoseconds since 14 Dec 1901 (i.e. the minimum time in the
32-bit unix time epoch). This enables us to handle dates up to 2486,
which solves the y2038 problem.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Redefine xfs_ictimestamp_t as a uint64_t typedef in preparation for the
bigtime functionality. Preserve the legacy structure format so that we
can let the compiler take care of the masking and shifting.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Move the buffer retry state machine logic to xfs_buf.c and call it once
from xfs_ioend instead of duplicating it three times for the three kinds
of buffers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
With the recent rework of the inode cluster flushing, we no longer
ever wait on the the inode flush "lock". It was never a lock in the
first place, just a completion to allow callers to wait for inode IO
to complete. We now never wait for flush completion as all inode
flushing is non-blocking. Hence we can get rid of all the iflock
infrastructure and instead just set and check a state flag.
Rename the XFS_IFLOCK flag to XFS_IFLUSHING, convert all the
xfs_iflock_nowait() test-and-set operations on that flag, and
replace all the xfs_ifunlock() calls to clear operations.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Delete repeated words in fs/xfs/.
{we, that, the, a, to, fork}
Change "it it" to "it is" in one location.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
To: linux-fsdevel@vger.kernel.org
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Use kmem_cache_zalloc() directly.
With the exception of xlog_ticket_alloc() which will be dealt on the
next patch for readability.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
xfs_iflush_done() does 3 distinct operations to the inodes attached
to the buffer. Separate these operations out into functions so that
it is easier to modify these operations independently in future.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Now that we have all the dirty inodes attached to the cluster
buffer, we don't actually have to do radix tree lookups to find
them. Sure, the radix tree is efficient, but walking a linked list
of just the dirty inodes attached to the buffer is much better.
We are also no longer dependent on having a locked inode passed into
the function to determine where to start the lookup. This means we
can drop it from the function call and treat all inodes the same.
We also make xfs_iflush_cluster skip inodes marked with
XFS_IRECLAIM. This we avoid races with inodes that reclaim is
actively referencing or are being re-initialised by inode lookup. If
they are actually dirty, they'll get written by a future cluster
flush....
We also add a shutdown check after obtaining the flush lock so that
we catch inodes that are dirty in memory and may have inconsistent
state due to the shutdown in progress. We abort these inodes
directly and so they remove themselves directly from the buffer list
and the AIL rather than having to wait for the buffer to be failed
and callbacks run to be processed correctly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Now we have a cached buffer on inode log items, we don't need
to do buffer lookups when flushing inodes anymore - all we need
to do is lock the buffer and we are ready to go.
This largely gets rid of the need for xfs_iflush(), which is
essentially just a mechanism to look up the buffer and flush the
inode to it. Instead, we can just call xfs_iflush_cluster() with a
few modifications to ensure it also flushes the inode we already
hold locked.
This allows the AIL inode item pushing to be almost entirely
non-blocking in XFS - we won't block unless memory allocation
for the cluster inode lookup blocks or the block device queues are
full.
Writeback during inode reclaim becomes a little more complex because
we now have to lock the buffer ourselves, but otherwise this change
is largely a functional no-op that removes a whole lot of code.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Rather than attach inodes to the cluster buffer just when we are
doing IO, attach the inodes to the cluster buffer when they are
dirtied. The means the buffer always carries a list of dirty inodes
that reference it, and we can use that list to make more fundamental
changes to inode writeback that aren't otherwise possible.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
When we dirty an inode, we are going to have to write it disk at
some point in the near future. This requires the inode cluster
backing buffer to be present in memory. Unfortunately, under severe
memory pressure we can reclaim the inode backing buffer while the
inode is dirty in memory, resulting in stalling the AIL pushing
because it has to do a read-modify-write cycle on the cluster
buffer.
When we have no memory available, the read of the cluster buffer
blocks the AIL pushing process, and this causes all sorts of issues
for memory reclaim as it requires inode writeback to make forwards
progress. Allocating a cluster buffer causes more memory pressure,
and results in more cluster buffers to be reclaimed, resulting in
more RMW cycles to be done in the AIL context and everything then
backs up on AIL progress. Only the synchronous inode cluster
writeback in the the inode reclaim code provides some level of
forwards progress guarantees that prevent OOM-killer rampages in
this situation.
Fix this by pinning the inode backing buffer to the inode log item
when the inode is first dirtied (i.e. in xfs_trans_log_inode()).
This may mean the first modification of an inode that has been held
in cache for a long time may block on a cluster buffer read, but
we can do that in transaction context and block safely until the
buffer has been allocated and read.
Once we have the cluster buffer, the inode log item takes a
reference to it, pinning it in memory, and attaches it to the log
item for future reference. This means we can always grab the cluster
buffer from the inode log item when we need it.
When the inode is finally cleaned and removed from the AIL, we can
drop the reference the inode log item holds on the cluster buffer.
Once all inodes on the cluster buffer are clean, the cluster buffer
will be unpinned and it will be available for memory reclaim to
reclaim again.
This avoids the issues with needing to do RMW cycles in the AIL
pushing context, and hence allows complete non-blocking inode
flushing to be performed by the AIL pushing context.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
xfs_ail_delete_one() is called directly from dquot and inode IO
completion, as well as from the generic xfs_trans_ail_delete()
function. Inodes are about to have their own failure handling, and
dquots will in future, too. Pull the clearing of the LI_FAILED flag
up into the callers so we can customise the code appropriately.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
When an buffer IO error occurs, we want to mark all
the log items attached to the buffer as failed. Open code
the error handling loop so that we can modify the flagging for the
different types of objects directly and independently of each other.
This also allows us to remove the ->iop_error method from the log
item operations.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Having different io completion callbacks for different inode states
makes things complex. We can detect if the inode is stale via the
XFS_ISTALE flag in IO completion, so we don't need a special
callback just for this.
This means inodes only have a single iodone callback, and inode IO
completion is entirely buffer centric at this point. Hence we no
longer need to use a log item callback at all as we can just call
xfs_iflush_done() directly from the buffer completions and walk the
buffer log item list to complete the all inodes under IO.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The inode log item is kind of special in that it can be aggregating
new changes in memory at the same time time existing changes are
being written back to disk. This means there are fields in the log
item that are accessed concurrently from contexts that don't share
any locking at all.
e.g. updating ili_last_fields occurs at flush time under the
ILOCK_EXCL and flush lock at flush time, under the flush lock at IO
completion time, and is read under the ILOCK_EXCL when the inode is
logged. Hence there is no actual serialisation between reading the
field during logging of the inode in transactions vs clearing the
field in IO completion.
We currently get away with this by the fact that we are only
clearing fields in IO completion, and nothing bad happens if we
accidentally log more of the inode than we actually modify. Worst
case is we consume a tiny bit more memory and log bandwidth.
However, if we want to do more complex state manipulations on the
log item that requires updates at all three of these potential
locations, we need to have some mechanism of serialising those
operations. To do this, introduce a spinlock into the log item to
serialise internal state.
This could be done via the xfs_inode i_flags_lock, but this then
leads to potential lock inversion issues where inode flag updates
need to occur inside locks that best nest inside the inode log item
locks (e.g. marking inodes stale during inode cluster freeing).
Using a separate spinlock avoids these sorts of problems and
simplifies future code.
This does not touch the use of ili_fields in the item formatting
code - that is entirely protected by the ILOCK_EXCL at this point in
time, so it remains untouched.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Matthew Wilcox (Oracle)