[ Upstream commit 0ccc3876e4b2a1559a4dbe3126dda4459d38a83b ]
Back in commit a89ca6f24f ("Btrfs: fix fsync after truncate when
no_holes feature is enabled") I added an assertion that is triggered when
an inline extent is found to assert that the length of the (uncompressed)
data the extent represents is the same as the i_size of the inode, since
that is true most of the time I couldn't find or didn't remembered about
any exception at that time. Later on the assertion was expanded twice to
deal with a case of a compressed inline extent representing a range that
matches the sector size followed by an expanding truncate, and another
case where fallocate can update the i_size of the inode without adding
or updating existing extents (if the fallocate range falls entirely within
the first block of the file). These two expansion/fixes of the assertion
were done by commit 7ed586d0a8241 ("Btrfs: fix assertion on fsync of
regular file when using no-holes feature") and commit 6399fb5a0b69a
("Btrfs: fix assertion failure during fsync in no-holes mode").
These however missed the case where an falloc expands the i_size of an
inode to exactly the sector size and inline extent exists, for example:
$ mkfs.btrfs -f -O no-holes /dev/sdc
$ mount /dev/sdc /mnt
$ xfs_io -f -c "pwrite -S 0xab 0 1096" /mnt/foobar
wrote 1096/1096 bytes at offset 0
1 KiB, 1 ops; 0.0002 sec (4.448 MiB/sec and 4255.3191 ops/sec)
$ xfs_io -c "falloc 1096 3000" /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
Segmentation fault
$ dmesg
[701253.602385] assertion failed: len == i_size || (len == fs_info->sectorsize && btrfs_file_extent_compression(leaf, extent) != BTRFS_COMPRESS_NONE) || (len < i_size && i_size < fs_info->sectorsize), file: fs/btrfs/tree-log.c, line: 4727
[701253.602962] ------------[ cut here ]------------
[701253.603224] kernel BUG at fs/btrfs/ctree.h:3533!
[701253.603503] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
[701253.603774] CPU: 2 PID: 7192 Comm: xfs_io Tainted: G W 5.0.0-rc8-btrfs-next-45 #1
[701253.604054] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
[701253.604650] RIP: 0010:assfail.constprop.23+0x18/0x1a [btrfs]
(...)
[701253.605591] RSP: 0018:ffffbb48c186bc48 EFLAGS: 00010286
[701253.605914] RAX: 00000000000000de RBX: ffff921d0a7afc08 RCX: 0000000000000000
[701253.606244] RDX: 0000000000000000 RSI: ffff921d36b16868 RDI: ffff921d36b16868
[701253.606580] RBP: ffffbb48c186bcf0 R08: 0000000000000000 R09: 0000000000000000
[701253.606913] R10: 0000000000000003 R11: 0000000000000000 R12: ffff921d05d2de18
[701253.607247] R13: ffff921d03b54000 R14: 0000000000000448 R15: ffff921d059ecf80
[701253.607769] FS: 00007f14da906700(0000) GS:ffff921d36b00000(0000) knlGS:0000000000000000
[701253.608163] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[701253.608516] CR2: 000056087ea9f278 CR3: 00000002268e8001 CR4: 00000000003606e0
[701253.608880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[701253.609250] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[701253.609608] Call Trace:
[701253.609994] btrfs_log_inode+0xdfb/0xe40 [btrfs]
[701253.610383] btrfs_log_inode_parent+0x2be/0xa60 [btrfs]
[701253.610770] ? do_raw_spin_unlock+0x49/0xc0
[701253.611150] btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
[701253.611537] btrfs_sync_file+0x3b2/0x440 [btrfs]
[701253.612010] ? do_sysinfo+0xb0/0xf0
[701253.612552] do_fsync+0x38/0x60
[701253.612988] __x64_sys_fsync+0x10/0x20
[701253.613360] do_syscall_64+0x60/0x1b0
[701253.613733] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[701253.614103] RIP: 0033:0x7f14da4e66d0
(...)
[701253.615250] RSP: 002b:00007fffa670fdb8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
[701253.615647] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f14da4e66d0
[701253.616047] RDX: 000056087ea9c260 RSI: 000056087ea9c260 RDI: 0000000000000003
[701253.616450] RBP: 0000000000000001 R08: 0000000000000020 R09: 0000000000000010
[701253.616854] R10: 000000000000009b R11: 0000000000000246 R12: 000056087ea9c260
[701253.617257] R13: 000056087ea9c240 R14: 0000000000000000 R15: 000056087ea9dd10
(...)
[701253.619941] ---[ end trace e088d74f132b6da5 ]---
Updating the assertion again to allow for this particular case would result
in a meaningless assertion, plus there is currently no risk of logging
content that would result in any corruption after a log replay if the size
of the data encoded in an inline extent is greater than the inode's i_size
(which is not currently possibe either with or without compression),
therefore just remove the assertion.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9bc574de590510eff899c3ca8dbaf013566b5efe upstream.
My fsstress modifications coupled with generic/475 uncovered a failure
to mount and replay the log if we hit a orphaned root. We do not want
to replay the log for an orphan root, but it's completely legitimate to
have an orphaned root with a log attached. Fix this by simply skipping
replaying the log. We still need to pin it's root node so that we do
not overwrite it while replaying other logs, as we re-read the log root
at every stage of the replay.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 410f954cb1d1c79ae485dd83a175f21954fd87cd upstream.
Sometimes when fsync'ing a file we need to log that other inodes exist and
when we need to do that we acquire a reference on the inodes and then drop
that reference using iput() after logging them.
That generally is not a problem except if we end up doing the final iput()
(dropping the last reference) on the inode and that inode has a link count
of 0, which can happen in a very short time window if the logging path
gets a reference on the inode while it's being unlinked.
In that case we end up getting the eviction callback, btrfs_evict_inode(),
invoked through the iput() call chain which needs to drop all of the
inode's items from its subvolume btree, and in order to do that, it needs
to join a transaction at the helper function evict_refill_and_join().
However because the task previously started a transaction at the fsync
handler, btrfs_sync_file(), it has current->journal_info already pointing
to a transaction handle and therefore evict_refill_and_join() will get
that transaction handle from btrfs_join_transaction(). From this point on,
two different problems can happen:
1) evict_refill_and_join() will often change the transaction handle's
block reserve (->block_rsv) and set its ->bytes_reserved field to a
value greater than 0. If evict_refill_and_join() never commits the
transaction, the eviction handler ends up decreasing the reference
count (->use_count) of the transaction handle through the call to
btrfs_end_transaction(), and after that point we have a transaction
handle with a NULL ->block_rsv (which is the value prior to the
transaction join from evict_refill_and_join()) and a ->bytes_reserved
value greater than 0. If after the eviction/iput completes the inode
logging path hits an error or it decides that it must fallback to a
transaction commit, the btrfs fsync handle, btrfs_sync_file(), gets a
non-zero value from btrfs_log_dentry_safe(), and because of that
non-zero value it tries to commit the transaction using a handle with
a NULL ->block_rsv and a non-zero ->bytes_reserved value. This makes
the transaction commit hit an assertion failure at
btrfs_trans_release_metadata() because ->bytes_reserved is not zero but
the ->block_rsv is NULL. The produced stack trace for that is like the
following:
[192922.917158] assertion failed: !trans->bytes_reserved, file: fs/btrfs/transaction.c, line: 816
[192922.917553] ------------[ cut here ]------------
[192922.917922] kernel BUG at fs/btrfs/ctree.h:3532!
[192922.918310] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
[192922.918666] CPU: 2 PID: 883 Comm: fsstress Tainted: G W 5.1.4-btrfs-next-47 #1
[192922.919035] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
[192922.919801] RIP: 0010:assfail.constprop.25+0x18/0x1a [btrfs]
(...)
[192922.920925] RSP: 0018:ffffaebdc8a27da8 EFLAGS: 00010286
[192922.921315] RAX: 0000000000000051 RBX: ffff95c9c16a41c0 RCX: 0000000000000000
[192922.921692] RDX: 0000000000000000 RSI: ffff95cab6b16838 RDI: ffff95cab6b16838
[192922.922066] RBP: ffff95c9c16a41c0 R08: 0000000000000000 R09: 0000000000000000
[192922.922442] R10: ffffaebdc8a27e70 R11: 0000000000000000 R12: ffff95ca731a0980
[192922.922820] R13: 0000000000000000 R14: ffff95ca84c73338 R15: ffff95ca731a0ea8
[192922.923200] FS: 00007f337eda4e80(0000) GS:ffff95cab6b00000(0000) knlGS:0000000000000000
[192922.923579] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[192922.923948] CR2: 00007f337edad000 CR3: 00000001e00f6002 CR4: 00000000003606e0
[192922.924329] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[192922.924711] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[192922.925105] Call Trace:
[192922.925505] btrfs_trans_release_metadata+0x10c/0x170 [btrfs]
[192922.925911] btrfs_commit_transaction+0x3e/0xaf0 [btrfs]
[192922.926324] btrfs_sync_file+0x44c/0x490 [btrfs]
[192922.926731] do_fsync+0x38/0x60
[192922.927138] __x64_sys_fdatasync+0x13/0x20
[192922.927543] do_syscall_64+0x60/0x1c0
[192922.927939] entry_SYSCALL_64_after_hwframe+0x49/0xbe
(...)
[192922.934077] ---[ end trace f00808b12068168f ]---
2) If evict_refill_and_join() decides to commit the transaction, it will
be able to do it, since the nested transaction join only increments the
transaction handle's ->use_count reference counter and it does not
prevent the transaction from getting committed. This means that after
eviction completes, the fsync logging path will be using a transaction
handle that refers to an already committed transaction. What happens
when using such a stale transaction can be unpredictable, we are at
least having a use-after-free on the transaction handle itself, since
the transaction commit will call kmem_cache_free() against the handle
regardless of its ->use_count value, or we can end up silently losing
all the updates to the log tree after that iput() in the logging path,
or using a transaction handle that in the meanwhile was allocated to
another task for a new transaction, etc, pretty much unpredictable
what can happen.
In order to fix both of them, instead of using iput() during logging, use
btrfs_add_delayed_iput(), so that the logging path of fsync never drops
the last reference on an inode, that step is offloaded to a safe context
(usually the cleaner kthread).
The assertion failure issue was sporadically triggered by the test case
generic/475 from fstests, which loads the dm error target while fsstress
is running, which lead to fsync failing while logging inodes with -EIO
errors and then trying later to commit the transaction, triggering the
assertion failure.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 06989c799f04810f6876900d4760c0edda369cf7 upstream.
When syncing the log, the final phase of a fsync operation, we need to
either create a log root's item or update the existing item in the log
tree of log roots, and that depends on the current value of the log
root's log_transid - if it's 1 we need to create the log root item,
otherwise it must exist already and we update it. Since there is no
synchronization between updating the log_transid and checking it for
deciding whether the log root's item needs to be created or updated, we
end up with a tiny race window that results in attempts to update the
item to fail because the item was not yet created:
CPU 1 CPU 2
btrfs_sync_log()
lock root->log_mutex
set log root's log_transid to 1
unlock root->log_mutex
btrfs_sync_log()
lock root->log_mutex
sets log root's
log_transid to 2
unlock root->log_mutex
update_log_root()
sees log root's log_transid
with a value of 2
calls btrfs_update_root(),
which fails with -EUCLEAN
and causes transaction abort
Until recently the race lead to a BUG_ON at btrfs_update_root(), but after
the recent commit 7ac1e464c4d47 ("btrfs: Don't panic when we can't find a
root key") we just abort the current transaction.
A sample trace of the BUG_ON() on a SLE12 kernel:
------------[ cut here ]------------
kernel BUG at ../fs/btrfs/root-tree.c:157!
Oops: Exception in kernel mode, sig: 5 [#1]
SMP NR_CPUS=2048 NUMA pSeries
(...)
Supported: Yes, External
CPU: 78 PID: 76303 Comm: rtas_errd Tainted: G X 4.4.156-94.57-default #1
task: c00000ffa906d010 ti: c00000ff42b08000 task.ti: c00000ff42b08000
NIP: d000000036ae5cdc LR: d000000036ae5cd8 CTR: 0000000000000000
REGS: c00000ff42b0b860 TRAP: 0700 Tainted: G X (4.4.156-94.57-default)
MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 22444484 XER: 20000000
CFAR: d000000036aba66c SOFTE: 1
GPR00: d000000036ae5cd8 c00000ff42b0bae0 d000000036bda220 0000000000000054
GPR04: 0000000000000001 0000000000000000 c00007ffff8d37c8 0000000000000000
GPR08: c000000000e19c00 0000000000000000 0000000000000000 3736343438312079
GPR12: 3930373337303434 c000000007a3a800 00000000007fffff 0000000000000023
GPR16: c00000ffa9d26028 c00000ffa9d261f8 0000000000000010 c00000ffa9d2ab28
GPR20: c00000ff42b0bc48 0000000000000001 c00000ff9f0d9888 0000000000000001
GPR24: c00000ffa9d26000 c00000ffa9d261e8 c00000ffa9d2a800 c00000ff9f0d9888
GPR28: c00000ffa9d26028 c00000ffa9d2aa98 0000000000000001 c00000ffa98f5b20
NIP [d000000036ae5cdc] btrfs_update_root+0x25c/0x4e0 [btrfs]
LR [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs]
Call Trace:
[c00000ff42b0bae0] [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] (unreliable)
[c00000ff42b0bba0] [d000000036b53610] btrfs_sync_log+0x2d0/0xc60 [btrfs]
[c00000ff42b0bce0] [d000000036b1785c] btrfs_sync_file+0x44c/0x4e0 [btrfs]
[c00000ff42b0bd80] [c00000000032e300] vfs_fsync_range+0x70/0x120
[c00000ff42b0bdd0] [c00000000032e44c] do_fsync+0x5c/0xb0
[c00000ff42b0be10] [c00000000032e8dc] SyS_fdatasync+0x2c/0x40
[c00000ff42b0be30] [c000000000009488] system_call+0x3c/0x100
Instruction dump:
7f43d378 4bffebb9 60000000 88d90008 3d220000 e8b90000 3b390009 e87a01f0
e8898e08 e8f90000 4bfd48e5 60000000 <0fe00000> e95b0060 39200004 394a0ea0
---[ end trace 8f2dc8f919cabab8 ]---
So fix this by doing the check of log_transid and updating or creating the
log root's item while holding the root's log_mutex.
Fixes: 7237f18336 ("Btrfs: fix tree logs parallel sync")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2cc8334270e281815c3850c3adea363c51f21e0d upstream.
When Filipe added the recursive directory logging stuff in
2f2ff0ee5e ("Btrfs: fix metadata inconsistencies after directory
fsync") he specifically didn't take the directory i_mutex for the
children directories that we need to log because of lockdep. This is
generally fine, but can lead to this WARN_ON() tripping if we happen to
run delayed deletion's in between our first search and our second search
of dir_item/dir_indexes for this directory. We expect this to happen,
so the WARN_ON() isn't necessary. Drop the WARN_ON() and add a comment
so we know why this case can happen.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0f375eed92b5a407657532637ed9652611a682f5 upstream.
In a scenario like the following:
mkdir /mnt/A # inode 258
mkdir /mnt/B # inode 259
touch /mnt/B/bar # inode 260
sync
mv /mnt/B/bar /mnt/A/bar
mv -T /mnt/A /mnt/B
fsync /mnt/B/bar
<power fail>
After replaying the log we end up with file bar having 2 hard links, both
with the name 'bar' and one in the directory with inode number 258 and the
other in the directory with inode number 259. Also, we end up with the
directory inode 259 still existing and with the directory inode 258 still
named as 'A', instead of 'B'. In this scenario, file 'bar' should only
have one hard link, located at directory inode 258, the directory inode
259 should not exist anymore and the name for directory inode 258 should
be 'B'.
This incorrect behaviour happens because when attempting to log the old
parents of an inode, we skip any parents that no longer exist. Fix this
by forcing a full commit if an old parent no longer exists.
A test case for fstests follows soon.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3d3a2e610ea5e7c6d4f9481ecce5d8e2d8317843 ]
Currently the code assumes that there's an implied barrier by the
sequence of code preceding the wakeup, namely the mutex unlock.
As Nikolay pointed out:
I think this is wrong (not your code) but the original assumption that
the RELEASE semantics provided by mutex_unlock is sufficient.
According to memory-barriers.txt:
Section 'LOCK ACQUISITION FUNCTIONS' states:
(2) RELEASE operation implication:
Memory operations issued before the RELEASE will be completed before the
RELEASE operation has completed.
Memory operations issued after the RELEASE *may* be completed before the
RELEASE operation has completed.
(I've bolded the may portion)
The example given there:
As an example, consider the following:
*A = a;
*B = b;
ACQUIRE
*C = c;
*D = d;
RELEASE
*E = e;
*F = f;
The following sequence of events is acceptable:
ACQUIRE, {*F,*A}, *E, {*C,*D}, *B, RELEASE
So if we assume that *C is modifying the flag which the waitqueue is checking,
and *E is the actual wakeup, then those accesses can be re-ordered...
IMHO this code should be considered broken...
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8434ec46c6e3232cebc25a910363b29f5c617820 ]
When logging an inode, at tree-log.c:copy_items(), if we call
btrfs_next_leaf() at the loop which checks for the need to log holes, we
need to make sure copy_items() returns the value 1 to its caller and
not 0 (on success). This is because the path the caller passed was
released and is now different from what is was before, and the caller
expects a return value of 0 to mean both success and that the path
has not changed, while a return value of 1 means both success and
signals the caller that it can not reuse the path, it has to perform
another tree search.
Even though this is a case that should not be triggered on normal
circumstances or very rare at least, its consequences can be very
unpredictable (especially when replaying a log tree).
Fixes: 16e7549f04 ("Btrfs: incompatible format change to remove hole extents")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 80c0b4210a963e31529e15bf90519708ec947596 ]
0, 1 and <0 can be returned by btrfs_next_leaf(), and when <0 is
returned, path->nodes[0] could be NULL, log_dir_items lacks such a
check for <0 and we may run into a null pointer dereference panic.
Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b98def7ca6e152ee55e36863dddf6f41f12d1dc6 ]
If errors were returned by btrfs_next_leaf(), replay_dir_deletes needs
to bail out, otherwise @ret would be forced to be 0 after 'break;' and
the caller won't be aware of it.
Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a8fca62aacc1599fea8e813d01e1955513e4fad upstream.
If a file has xattrs, we fsync it, to ensure we clear the flags
BTRFS_INODE_NEEDS_FULL_SYNC and BTRFS_INODE_COPY_EVERYTHING from its
inode, the current transaction commits and then we fsync it (without
either of those bits being set in its inode), we end up not logging
all its xattrs. This results in deleting all xattrs when replying the
log after a power failure.
Trivial reproducer
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/foobar
$ setfattr -n user.xa -v qwerty /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
$ sync
$ xfs_io -c "pwrite -S 0xab 0 64K" /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
<power failure>
$ mount /dev/sdb /mnt
$ getfattr --absolute-names --dump /mnt/foobar
<empty output>
$
So fix this by making sure all xattrs are logged if we log a file's inode
item and neither the flags BTRFS_INODE_NEEDS_FULL_SYNC nor
BTRFS_INODE_COPY_EVERYTHING were set in the inode.
Fixes: 36283bf777 ("Btrfs: fix fsync xattr loss in the fast fsync path")
Cc: <stable@vger.kernel.org> # 4.2+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0dde10bed2c44a4024eb446cc72fe4e0cb97ec06 upstream.
There is no need for the extra pair of parentheses, remove it. This
fixes the following warning when building with clang:
fs/btrfs/tree-log.c:3694:10: warning: equality comparison with extraneous
parentheses [-Wparentheses-equality]
if ((i == (nr - 1)))
~~^~~~~~~~~~~
Also remove the unnecessary parentheses around the substraction.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 900c9981680067573671ecc5cbfa7c5770be3a40 upstream.
The highest objectid, which is assigned to new inode, is decided at
the time of initializing fs roots. However, in cases where log replay
gets processed, the btree which fs root owns might be changed, so we
have to search it again for the highest objectid, otherwise creating
new inode would end up with -EEXIST.
cc: <stable@vger.kernel.org> v4.4-rc6+
Fixes: f32e48e925 ("Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55237a5f2431a72435e3ed39e4306e973c0446b7 upstream.
It's possible that btrfs_sync_log() bails out after one of the two
btrfs_write_marked_extents() which convert extent state's state bit into
EXTENT_NEED_WAIT from EXTENT_DIRTY/EXTENT_NEW, however only EXTENT_DIRTY
and EXTENT_NEW are searched by free_log_tree() so that those extent states
with EXTENT_NEED_WAIT lead to memory leak.
cc: <stable@vger.kernel.org>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1846430c24d66e85cc58286b3319c82cd54debb2 upstream.
In cases that the whole fs flips into readonly status due to failures in
critical sections, then log tree's blocks are still dirty, and this leads
to a crash during umount time, the crash is about use-after-free,
umount
-> close_ctree
-> stop workers
-> iput(btree_inode)
-> iput_final
-> write_inode_now
-> ...
-> queue job on stop'd workers
cc: <stable@vger.kernel.org> v3.12+
Fixes: 681ae50917 ("Btrfs: cleanup reserved space when freeing tree log on error")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 781feef7e6befafd4d9787d1f7ada1f9ccd504e4 ]
While checking INODE_REF/INODE_EXTREF for a corner case, we may acquire a
different inode's log_mutex with holding the current inode's log_mutex, and
lockdep has complained this with a possilble deadlock warning.
Fix this by using mutex_lock_nested() when processing the other inode's
log_mutex.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2a7bf53f577e49c43de4ffa7776056de26db65d9 upstream.
If a log tree has a layout like the following:
leaf N:
...
item 240 key (282 DIR_LOG_ITEM 0) itemoff 8189 itemsize 8
dir log end 1275809046
leaf N + 1:
item 0 key (282 DIR_LOG_ITEM 3936149215) itemoff 16275 itemsize 8
dir log end 18446744073709551615
...
When we pass the value 1275809046 + 1 as the parameter start_ret to the
function tree-log.c:find_dir_range() (done by replay_dir_deletes()), we
end up with path->slots[0] having the value 239 (points to the last item
of leaf N, item 240). Because the dir log item in that position has an
offset value smaller than *start_ret (1275809046 + 1) we need to move on
to the next leaf, however the logic for that is wrong since it compares
the current slot to the number of items in the leaf, which is smaller
and therefore we don't lookup for the next leaf but instead we set the
slot to point to an item that does not exist, at slot 240, and we later
operate on that slot which has unexpected content or in the worst case
can result in an invalid memory access (accessing beyond the last page
of leaf N's extent buffer).
So fix the logic that checks when we need to lookup at the next leaf
by first incrementing the slot and only after to check if that slot
is beyond the last item of the current leaf.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Fixes: e02119d5a7 (Btrfs: Add a write ahead tree log to optimize synchronous operations)
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Modified changelog for clarity and correctness]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull btrfs fixes from Chris Mason:
"My patch fixes the btrfs list_head abuse that we tracked down during
Dave Jones' memory corruption investigation. With both Jens and my
patches in place, I'm no longer able to trigger problems.
Filipe is fixing a difficult old bug between snapshots, balance and
send. Dave is cooking a few more for the next rc, but these are tested
and ready"
* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix races on root_log_ctx lists
btrfs: fix incremental send failure caused by balance
btrfs_remove_all_log_ctxs takes a shortcut where it avoids walking the
list because it knows all of the waiters are patiently waiting for the
commit to finish.
But, there's a small race where btrfs_sync_log can remove itself from
the list if it finds a log commit is already done. Also, it uses
list_del_init() to remove itself from the list, but there's no way to
know if btrfs_remove_all_log_ctxs has already run, so we don't know for
sure if it is safe to call list_del_init().
This gets rid of all the shortcuts for btrfs_remove_all_log_ctxs(), and
just calls it with the proper locking.
This is part two of the corruption fixed by cbd60aa7cd. I should have
done this in the first place, but convinced myself the optimizations were
safe. A 12 hour run of dbench 2048 will eventually trigger a list debug
WARN_ON for the list_del_init() in btrfs_sync_log().
Fixes: d1433debe7
Reported-by: Dave Jones <davej@codemonkey.org.uk>
cc: stable@vger.kernel.org # 3.15+
Signed-off-by: Chris Mason <clm@fb.com>
Pull btrfs updates from Chris Mason:
"This is a big variety of fixes and cleanups.
Liu Bo continues to fixup fuzzer related problems, and some of Josef's
cleanups are prep for his bigger extent buffer changes (slated for
v4.10)"
* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (39 commits)
Revert "btrfs: let btrfs_delete_unused_bgs() to clean relocated bgs"
Btrfs: remove unnecessary btrfs_mark_buffer_dirty in split_leaf
Btrfs: don't BUG() during drop snapshot
btrfs: fix btrfs_no_printk stub helper
Btrfs: memset to avoid stale content in btree leaf
btrfs: parent_start initialization cleanup
btrfs: Remove already completed TODO comment
btrfs: Do not reassign count in btrfs_run_delayed_refs
btrfs: fix a possible umount deadlock
Btrfs: fix memory leak in do_walk_down
btrfs: btrfs_debug should consume fs_info when DEBUG is not defined
btrfs: convert send's verbose_printk to btrfs_debug
btrfs: convert pr_* to btrfs_* where possible
btrfs: convert printk(KERN_* to use pr_* calls
btrfs: unsplit printed strings
btrfs: clean the old superblocks before freeing the device
Btrfs: kill BUG_ON in run_delayed_tree_ref
Btrfs: don't leak reloc root nodes on error
btrfs: squash lines for simple wrapper functions
Btrfs: improve check_node to avoid reading corrupted nodes
...
CodingStyle chapter 2:
"[...] never break user-visible strings such as printk messages,
because that breaks the ability to grep for them."
This patch unsplits user-visible strings.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a lot of random ints in btrfs_fs_info that can be put into flags. This
is mostly equivalent with the exception of how we deal with quota going on or
off, now instead we set a flag when we are turning it on or off and deal with
that appropriately, rather than just having a pending state that the current
quota_enabled gets set to. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use a btrfs_log_ctx structure to pass information into the
tree log commit, and get error values out. It gets added to a per
log-transaction list which we walk when things go bad.
Commit d1433debe added an optimization to skip waiting for the log
commit, but didn't take root_log_ctx out of the list. This
patch makes sure we remove things before exiting.
Signed-off-by: Chris Mason <clm@fb.com>
Fixes: d1433debe7
cc: stable@vger.kernel.org # 3.15+
Commit 44f714dae5 ("Btrfs: improve performance on fsync against new
inode after rename/unlink"), which landed in 4.8-rc2, introduced a
possibility for a deadlock due to double locking of an inode's log mutex
by the same task, which lockdep reports with:
[23045.433975] =============================================
[23045.434748] [ INFO: possible recursive locking detected ]
[23045.435426] 4.7.0-rc6-btrfs-next-34+ #1 Not tainted
[23045.436044] ---------------------------------------------
[23045.436044] xfs_io/3688 is trying to acquire lock:
[23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044]
but task is already holding lock:
[23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044]
other info that might help us debug this:
[23045.436044] Possible unsafe locking scenario:
[23045.436044] CPU0
[23045.436044] ----
[23045.436044] lock(&ei->log_mutex);
[23045.436044] lock(&ei->log_mutex);
[23045.436044]
*** DEADLOCK ***
[23045.436044] May be due to missing lock nesting notation
[23045.436044] 3 locks held by xfs_io/3688:
[23045.436044] #0: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffffa035f2ae>] btrfs_sync_file+0x14e/0x425 [btrfs]
[23045.436044] #1: (sb_internal#2){.+.+.+}, at: [<ffffffff8118446b>] __sb_start_write+0x5f/0xb0
[23045.436044] #2: (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044]
stack backtrace:
[23045.436044] CPU: 4 PID: 3688 Comm: xfs_io Not tainted 4.7.0-rc6-btrfs-next-34+ #1
[23045.436044] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[23045.436044] 0000000000000000 ffff88022f5f7860 ffffffff8127074d ffffffff82a54b70
[23045.436044] ffffffff82a54b70 ffff88022f5f7920 ffffffff81092897 ffff880228015d68
[23045.436044] 0000000000000000 ffffffff82a54b70 ffffffff829c3f00 ffff880228015d68
[23045.436044] Call Trace:
[23045.436044] [<ffffffff8127074d>] dump_stack+0x67/0x90
[23045.436044] [<ffffffff81092897>] __lock_acquire+0xcbb/0xe4e
[23045.436044] [<ffffffff8109155f>] ? mark_lock+0x24/0x201
[23045.436044] [<ffffffff8109179a>] ? mark_held_locks+0x5e/0x74
[23045.436044] [<ffffffff81092de0>] lock_acquire+0x12f/0x1c3
[23045.436044] [<ffffffff81092de0>] ? lock_acquire+0x12f/0x1c3
[23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044] [<ffffffff814a51a4>] mutex_lock_nested+0x77/0x3a7
[23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044] [<ffffffffa039705e>] ? btrfs_release_delayed_node+0xb/0xd [btrfs]
[23045.436044] [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044] [<ffffffff810a0ed1>] ? vprintk_emit+0x453/0x465
[23045.436044] [<ffffffffa0385a61>] btrfs_log_inode+0x66e/0xc95 [btrfs]
[23045.436044] [<ffffffffa03c084d>] log_new_dir_dentries+0x26c/0x359 [btrfs]
[23045.436044] [<ffffffffa03865aa>] btrfs_log_inode_parent+0x4a6/0x628 [btrfs]
[23045.436044] [<ffffffffa0387552>] btrfs_log_dentry_safe+0x5a/0x75 [btrfs]
[23045.436044] [<ffffffffa035f464>] btrfs_sync_file+0x304/0x425 [btrfs]
[23045.436044] [<ffffffff811acaf4>] vfs_fsync_range+0x8c/0x9e
[23045.436044] [<ffffffff811acb22>] vfs_fsync+0x1c/0x1e
[23045.436044] [<ffffffff811acc79>] do_fsync+0x31/0x4a
[23045.436044] [<ffffffff811ace99>] SyS_fsync+0x10/0x14
[23045.436044] [<ffffffff814a88e5>] entry_SYSCALL_64_fastpath+0x18/0xa8
[23045.436044] [<ffffffff8108f039>] ? trace_hardirqs_off_caller+0x3f/0xaa
An example reproducer for this is:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/dir
$ touch /mnt/dir/foo
$ sync
$ mv /mnt/dir/foo /mnt/dir/bar
$ touch /mnt/dir/foo
$ xfs_io -c "fsync" /mnt/dir/bar
This is because while logging the inode of file bar we end up logging its
parent directory (since its inode has an unlink_trans field matching the
current transaction id due to the rename operation), which in turn logs
the inodes for all its new dentries, so that the new inode for the new
file named foo gets logged which in turn triggered another logging attempt
for the inode we are fsync'ing, since that inode had an old name that
corresponds to the name of the new inode.
So fix this by ensuring that when logging the inode for a new dentry that
has a name matching an old name of some other inode, we don't log again
the original inode that we are fsync'ing.
Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
When doing log replay at mount time(after power loss), qgroup will leak
numbers of replayed data extents.
The cause is almost the same of balance.
So fix it by manually informing qgroup for owner changed extents.
The bug can be detected by btrfs/119 test case.
Cc: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
With commit 56f23fdbb6 ("Btrfs: fix file/data loss caused by fsync after
rename and new inode") we got simple fix for a functional issue when the
following sequence of actions is done:
at transaction N
create file A at directory D
at transaction N + M (where M >= 1)
move/rename existing file A from directory D to directory E
create a new file named A at directory D
fsync the new file
power fail
The solution was to simply detect such scenario and fallback to a full
transaction commit when we detect it. However this turned out to had a
significant impact on throughput (and a bit on latency too) for benchmarks
using the dbench tool, which simulates real workloads from smbd (Samba)
servers. For example on a test vm (with a debug kernel):
Unpatched:
Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms
Patched:
Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms
The patched results (this patch is applied) are similar to the results of
a kernel with the commit 56f23fdbb6 ("Btrfs: fix file/data loss caused
by fsync after rename and new inode") reverted.
This change avoids the fallback to a transaction commit and instead makes
sure all the names of the conflicting inode (the one that had a name in a
past transaction that matches the name of the new file in the same parent
directory) are logged so that at log replay time we don't lose neither the
new file nor the old file, and the old file gets the name it was renamed
to.
This also ends up avoiding a full transaction commit for a similar case
that involves an unlink instead of a rename of the old file:
at transaction N
create file A at directory D
at transaction N + M (where M >= 1)
remove file A
create a new file named A at directory D
fsync the new file
power fail
Signed-off-by: Filipe Manana <fdmanana@suse.com>
__btrfs_abort_transaction doesn't use its root parameter except to
obtain an fs_info pointer. We can obtain that from trans->root->fs_info
for now and from trans->fs_info in a later patch.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_test_opt and friends only use the root pointer to access
the fs_info. Let's pass the fs_info directly in preparation to
eliminate similar patterns all over btrfs.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use read_node_slot() to read btree node and it has two cases,
a) slot is out of range, which means 'no such entry'
b) we fail to read the block, due to checksum fails or corrupted
content or not with uptodate flag.
But we're returning NULL in both cases, this makes it return -ENOENT
in case a) and return -EIO in case b), and this fixes its callers
as well as btrfs_search_forward() 's caller to catch the new errors.
The problem is reported by Peter Becker, and I can manage to
hit the same BUG_ON by mounting my fuzz image.
Reported-by: Peter Becker <floyd.net@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs fixes from Chris Mason:
"The most user visible change here is a fix for our recent superblock
validation checks that were causing problems on non-4k pagesized
systems"
* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: btrfs_check_super_valid: Allow 4096 as stripesize
btrfs: remove build fixup for qgroup_account_snapshot
btrfs: use new error message helper in qgroup_account_snapshot
btrfs: avoid blocking open_ctree from cleaner_kthread
Btrfs: don't BUG_ON() in btrfs_orphan_add
btrfs: account for non-CoW'd blocks in btrfs_abort_transaction
Btrfs: check if extent buffer is aligned to sectorsize
btrfs: Use correct format specifier
Thanks to fuzz testing, we can pass an invalid bytenr to extent buffer
via alloc_extent_buffer(). An unaligned eb can have more pages than it
should have, which ends up extent buffer's leak or some corrupted content
in extent buffer.
This adds a warning to let us quickly know what was happening.
Now that alloc_extent_buffer() no more returns NULL, this changes its
caller and callers of its caller to match with the new error
handling.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs cleanups and fixes from Chris Mason:
"We have another round of fixes and a few cleanups.
I have a fix for short returns from btrfs_copy_from_user, which
finally nails down a very hard to find regression we added in v4.6.
Dave is pushing around gfp parameters, mostly to cleanup internal apis
and make it a little more consistent.
The rest are smaller fixes, and one speelling fixup patch"
* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (22 commits)
Btrfs: fix handling of faults from btrfs_copy_from_user
btrfs: fix string and comment grammatical issues and typos
btrfs: scrub: Set bbio to NULL before calling btrfs_map_block
Btrfs: fix unexpected return value of fiemap
Btrfs: free sys_array eb as soon as possible
btrfs: sink gfp parameter to convert_extent_bit
btrfs: make state preallocation more speculative in __set_extent_bit
btrfs: untangle gotos a bit in convert_extent_bit
btrfs: untangle gotos a bit in __clear_extent_bit
btrfs: untangle gotos a bit in __set_extent_bit
btrfs: sink gfp parameter to set_record_extent_bits
btrfs: sink gfp parameter to set_extent_new
btrfs: sink gfp parameter to set_extent_defrag
btrfs: sink gfp parameter to set_extent_delalloc
btrfs: sink gfp parameter to clear_extent_dirty
btrfs: sink gfp parameter to clear_record_extent_bits
btrfs: sink gfp parameter to clear_extent_bits
btrfs: sink gfp parameter to set_extent_bits
btrfs: make find_workspace warn if there are no workspaces
btrfs: make find_workspace always succeed
...
Pull btrfs updates from Chris Mason:
"This has our merge window series of cleanups and fixes. These target
a wide range of issues, but do include some important fixes for
qgroups, O_DIRECT, and fsync handling. Jeff Mahoney moved around a
few definitions to make them easier for userland to consume.
Also whiteout support is included now that issues with overlayfs have
been cleared up.
I have one more fix pending for page faults during btrfs_copy_from_user,
but I wanted to get this bulk out the door first"
* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (90 commits)
btrfs: fix memory leak during RAID 5/6 device replacement
Btrfs: add semaphore to synchronize direct IO writes with fsync
Btrfs: fix race between block group relocation and nocow writes
Btrfs: fix race between fsync and direct IO writes for prealloc extents
Btrfs: fix number of transaction units for renames with whiteout
Btrfs: pin logs earlier when doing a rename exchange operation
Btrfs: unpin logs if rename exchange operation fails
Btrfs: fix inode leak on failure to setup whiteout inode in rename
btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT
Btrfs: pin log earlier when renaming
Btrfs: unpin log if rename operation fails
Btrfs: don't do unnecessary delalloc flushes when relocating
Btrfs: don't wait for unrelated IO to finish before relocation
Btrfs: fix empty symlink after creating symlink and fsync parent dir
Btrfs: fix for incorrect directory entries after fsync log replay
btrfs: build fixup for qgroup_account_snapshot
btrfs: qgroup: Fix qgroup accounting when creating snapshot
Btrfs: fix fspath error deallocation
btrfs: make find_workspace warn if there are no workspaces
btrfs: make find_workspace always succeed
...
Due to the optimization of lockless direct IO writes (the inode's i_mutex
is not held) introduced in commit 38851cc19a ("Btrfs: implement unlocked
dio write"), we started having races between such writes with concurrent
fsync operations that use the fast fsync path. These races were addressed
in the patches titled "Btrfs: fix race between fsync and lockless direct
IO writes" and "Btrfs: fix race between fsync and direct IO writes for
prealloc extents". The races happened because the direct IO path, like
every other write path, does create extent maps followed by the
corresponding ordered extents while the fast fsync path collected first
ordered extents and then it collected extent maps. This made it possible
to log file extent items (based on the collected extent maps) without
waiting for the corresponding ordered extents to complete (get their IO
done). The two fixes mentioned before added a solution that consists of
making the direct IO path create first the ordered extents and then the
extent maps, while the fsync path attempts to collect any new ordered
extents once it collects the extent maps. This was simple and did not
require adding any synchonization primitive to any data structure (struct
btrfs_inode for example) but it makes things more fragile for future
development endeavours and adds an exceptional approach compared to the
other write paths.
This change adds a read-write semaphore to the btrfs inode structure and
makes the direct IO path create the extent maps and the ordered extents
while holding read access on that semaphore, while the fast fsync path
collects extent maps and ordered extents while holding write access on
that semaphore. The logic for direct IO write path is encapsulated in a
new helper function that is used both for cow and nocow direct IO writes.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
If we create a symlink, fsync its parent directory, crash/power fail and
mount the filesystem, we end up with an empty symlink, which not only is
useless it's also not allowed in linux (the man page symlink(2) is well
explicit about that). So we just need to make sure to fully log an inode
if it's a symlink, to ensure its inline extent gets logged, ensuring the
same behaviour as ext3, ext4, xfs, reiserfs, f2fs, nilfs2, etc.
Example reproducer:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/testdir
$ sync
$ ln -s /mnt/foo /mnt/testdir/bar
$ xfs_io -c fsync /mnt/testdir
<power fail>
$ mount /dev/sdb /mnt
$ readlink /mnt/testdir/bar
<empty string>
A test case for fstests follows soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
If we move a directory to a new parent and later log that parent and don't
explicitly log the old parent, when we replay the log we can end up with
entries for the moved directory in both the old and new parent directories.
Besides being ilegal to have directories with multiple hard links in linux,
it also resulted in the leaving the inode item with a link count of 1.
A similar issue also happens if we move a regular file - after the log tree
is replayed the file has a link in both the old and new parent directories,
when it should be only at the new directory.
Sample reproducer:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ mkdir /mnt/x
$ mkdir /mnt/y
$ touch /mnt/x/foo
$ mkdir /mnt/y/z
$ sync
$ ln /mnt/x/foo /mnt/x/bar
$ mv /mnt/y/z /mnt/x/z
< power fail >
$ mount /dev/sdc /mnt
$ ls -1Ri /mnt
/mnt:
257 x
258 y
/mnt/x:
259 bar
259 foo
260 z
/mnt/x/z:
/mnt/y:
260 z
/mnt/y/z:
$ umount /dev/sdc
$ btrfs check /dev/sdc
Checking filesystem on /dev/sdc
UUID: a67e2c4a-a4b4-4fdc-b015-9d9af1e344be
checking extents
checking free space cache
checking fs roots
root 5 inode 260 errors 2000, link count wrong
unresolved ref dir 257 index 4 namelen 1 name z filetype 2 errors 0
unresolved ref dir 258 index 2 namelen 1 name z filetype 2 errors 0
(...)
Attempting to remove the directory becomes impossible:
$ mount /dev/sdc /mnt
$ rmdir /mnt/y/z
$ ls -lh /mnt/y
ls: cannot access /mnt/y/z: No such file or directory
total 0
d????????? ? ? ? ? ? z
$ rmdir /mnt/x/z
rmdir: failed to remove ‘/mnt/x/z’: Stale file handle
$ ls -lh /mnt/x
ls: cannot access /mnt/x/z: Stale file handle
total 0
-rw-r--r-- 2 root root 0 Apr 6 18:06 bar
-rw-r--r-- 2 root root 0 Apr 6 18:06 foo
d????????? ? ? ? ? ? z
So make sure that on rename we set the last_unlink_trans value for our
inode, even if it's a directory, to the value of the current transaction's
ID and that if the new parent directory is logged that we fallback to a
transaction commit.
A test case for fstests is being submitted as well.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
btrfs_std_error() handles errors, puts FS into readonly mode
(as of now). So its good idea to rename it to btrfs_handle_fs_error().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ edit changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
If we rename an inode A (be it a file or a directory), create a new
inode B with the old name of inode A and under the same parent directory,
fsync inode B and then power fail, at log tree replay time we end up
removing inode A completely. If inode A is a directory then all its files
are gone too.
Example scenarios where this happens:
This is reproducible with the following steps, taken from a couple of
test cases written for fstests which are going to be submitted upstream
soon:
# Scenario 1
mkfs.btrfs -f /dev/sdc
mount /dev/sdc /mnt
mkdir -p /mnt/a/x
echo "hello" > /mnt/a/x/foo
echo "world" > /mnt/a/x/bar
sync
mv /mnt/a/x /mnt/a/y
mkdir /mnt/a/x
xfs_io -c fsync /mnt/a/x
<power failure happens>
The next time the fs is mounted, log tree replay happens and
the directory "y" does not exist nor do the files "foo" and
"bar" exist anywhere (neither in "y" nor in "x", nor the root
nor anywhere).
# Scenario 2
mkfs.btrfs -f /dev/sdc
mount /dev/sdc /mnt
mkdir /mnt/a
echo "hello" > /mnt/a/foo
sync
mv /mnt/a/foo /mnt/a/bar
echo "world" > /mnt/a/foo
xfs_io -c fsync /mnt/a/foo
<power failure happens>
The next time the fs is mounted, log tree replay happens and the
file "bar" does not exists anymore. A file with the name "foo"
exists and it matches the second file we created.
Another related problem that does not involve file/data loss is when a
new inode is created with the name of a deleted snapshot and we fsync it:
mkfs.btrfs -f /dev/sdc
mount /dev/sdc /mnt
mkdir /mnt/testdir
btrfs subvolume snapshot /mnt /mnt/testdir/snap
btrfs subvolume delete /mnt/testdir/snap
rmdir /mnt/testdir
mkdir /mnt/testdir
xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir
<power failure>
The next time the fs is mounted the log replay procedure fails because
it attempts to delete the snapshot entry (which has dir item key type
of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry,
resulting in the following error that causes mount to fail:
[52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257
[52174.512570] ------------[ cut here ]------------
[52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]()
[52174.514681] BTRFS: Transaction aborted (error -2)
[52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc
[52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1
[52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758
[52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd
[52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88
[52174.524053] Call Trace:
[52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90
[52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2
[52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs]
[52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50
[52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs]
[52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284
[52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs]
[52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs]
[52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs]
[52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs]
[52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs]
[52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs]
[52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs]
[52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs]
[52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs]
[52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf
[52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131
[52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde
[52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs]
[52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf
[52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3
[52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131
[52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde
[52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8
[52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59
[52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f
[52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b
[52174.561288] ---[ end trace 6b53049efb1a3ea6 ]---
Fix this by forcing a transaction commit when such cases happen.
This means we check in the commit root of the subvolume tree if there
was any other inode with the same reference when the inode we are
fsync'ing is a new inode (created in the current transaction).
Test cases for fstests, covering all the scenarios given above, were
submitted upstream for fstests:
* fstests: generic test for fsync after renaming directory
https://patchwork.kernel.org/patch/8694281/
* fstests: generic test for fsync after renaming file
https://patchwork.kernel.org/patch/8694301/
* fstests: add btrfs test for fsync after snapshot deletion
https://patchwork.kernel.org/patch/8670671/
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
So that its better organized.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
