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commit 4203e968947071586a98b5314fd7ffdea3b4f971 upstream.
We've historically had reports of being unable to mount file systems
because the tree log root couldn't be read. Usually this is the "parent
transid failure", but could be any of the related errors, including
"fsid mismatch" or "bad tree block", depending on which block got
allocated.
The modification of the individual log root items are serialized on the
per-log root root_mutex. This means that any modification to the
per-subvol log root_item is completely protected.
However we update the root item in the log root tree outside of the log
root tree log_mutex. We do this in order to allow multiple subvolumes
to be updated in each log transaction.
This is problematic however because when we are writing the log root
tree out we update the super block with the _current_ log root node
information. Since these two operations happen independently of each
other, you can end up updating the log root tree in between writing out
the dirty blocks and setting the super block to point at the current
root.
This means we'll point at the new root node that hasn't been written
out, instead of the one we should be pointing at. Thus whatever garbage
or old block we end up pointing at complains when we mount the file
system later and try to replay the log.
Fix this by copying the log's root item into a local root item copy.
Then once we're safely under the log_root_tree->log_mutex we update the
root item in the log_root_tree. This way we do not modify the
log_root_tree while we're committing it, fixing the problem.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Chris Mason <clm@fb.com>
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>
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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>
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commit 803f0f64d17769071d7287d9e3e3b79a3e1ae937 upstream.
In order to avoid searches on a log tree when unlinking an inode, we check
if the inode being unlinked was logged in the current transaction, as well
as the inode of its parent directory. When any of the inodes are logged,
we proceed to delete directory items and inode reference items from the
log, to ensure that if a subsequent fsync of only the inode being unlinked
or only of the parent directory when the other is not fsync'ed as well,
does not result in the entry still existing after a power failure.
That check however is not reliable when one of the inodes involved (the
one being unlinked or its parent directory's inode) is evicted, since the
logged_trans field is transient, that is, it is not stored on disk, so it
is lost when the inode is evicted and loaded into memory again (which is
set to zero on load). As a consequence the checks currently being done by
btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always
return true if the inode was evicted before, regardless of the inode
having been logged or not before (and in the current transaction), this
results in the dentry being unlinked still existing after a log replay
if after the unlink operation only one of the inodes involved is fsync'ed.
Example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/dir
$ touch /mnt/dir/foo
$ xfs_io -c fsync /mnt/dir/foo
# Keep an open file descriptor on our directory while we evict inodes.
# We just want to evict the file's inode, the directory's inode must not
# be evicted.
$ ( cd /mnt/dir; while true; do :; done ) &
$ pid=$!
# Wait a bit to give time to background process to chdir to our test
# directory.
$ sleep 0.5
# Trigger eviction of the file's inode.
$ echo 2 > /proc/sys/vm/drop_caches
# Unlink our file and fsync the parent directory. After a power failure
# we don't expect to see the file anymore, since we fsync'ed the parent
# directory.
$ rm -f $SCRATCH_MNT/dir/foo
$ xfs_io -c fsync /mnt/dir
<power failure>
$ mount /dev/sdb /mnt
$ ls /mnt/dir
foo
$
--> file still there, unlink not persisted despite explicit fsync on dir
Fix this by checking if the inode has the full_sync bit set in its runtime
flags as well, since that bit is set everytime an inode is loaded from
disk, or for other less common cases such as after a shrinking truncate
or failure to allocate extent maps for holes, and gets cleared after the
first fsync. Also consider the inode as possibly logged only if it was
last modified in the current transaction (besides having the full_fsync
flag set).
Fixes: 3a5f1d458ad161 ("Btrfs: Optimize btree walking while logging inodes")
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>
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commit d1d832a0b51dd9570429bb4b81b2a6c1759e681a upstream.
When we log an inode, regardless of logging it completely or only that it
exists, we always update it as logged (logged_trans and last_log_commit
fields of the inode are updated). This is generally fine and avoids future
attempts to log it from having to do repeated work that brings no value.
However, if we write data to a file, then evict its inode after all the
dealloc was flushed (and ordered extents completed), rename the file and
fsync it, we end up not logging the new extents, since the rename may
result in logging that the inode exists in case the parent directory was
logged before. The following reproducer shows and explains how this can
happen:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/dir
$ touch /mnt/dir/foo
$ touch /mnt/dir/bar
# Do a direct IO write instead of a buffered write because with a
# buffered write we would need to make sure dealloc gets flushed and
# complete before we do the inode eviction later, and we can not do that
# from user space with call to things such as sync(2) since that results
# in a transaction commit as well.
$ xfs_io -d -c "pwrite -S 0xd3 0 4K" /mnt/dir/bar
# Keep the directory dir in use while we evict inodes. We want our file
# bar's inode to be evicted but we don't want our directory's inode to
# be evicted (if it were evicted too, we would not be able to reproduce
# the issue since the first fsync below, of file foo, would result in a
# transaction commit.
$ ( cd /mnt/dir; while true; do :; done ) &
$ pid=$!
# Wait a bit to give time for the background process to chdir.
$ sleep 0.1
# Evict all inodes, except the inode for the directory dir because it is
# currently in use by our background process.
$ echo 2 > /proc/sys/vm/drop_caches
# fsync file foo, which ends up persisting information about the parent
# directory because it is a new inode.
$ xfs_io -c fsync /mnt/dir/foo
# Rename bar, this results in logging that this inode exists (inode item,
# names, xattrs) because the parent directory is in the log.
$ mv /mnt/dir/bar /mnt/dir/baz
# Now fsync baz, which ends up doing absolutely nothing because of the
# rename operation which logged that the inode exists only.
$ xfs_io -c fsync /mnt/dir/baz
<power failure>
$ mount /dev/sdb /mnt
$ od -t x1 -A d /mnt/dir/baz
0000000
--> Empty file, data we wrote is missing.
Fix this by not updating last_sub_trans of an inode when we are logging
only that it exists and the inode was not yet logged since it was loaded
from disk (full_sync bit set), this is enough to make btrfs_inode_in_log()
return false for this scenario and make us log the inode. The logged_trans
of the inode is still always setsince that alone is used to track if names
need to be deleted as part of unlink operations.
Fixes: 257c62e1bce03e ("Btrfs: avoid tree log commit when there are no changes")
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>
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commit 60d9f50308e5df19bc18c2fefab0eba4a843900a upstream.
While logging an inode we follow its ancestors and for each one we mark
it as logged in the current transaction, even if we have not logged it.
As a consequence if we change an attribute of an ancestor, such as the
UID or GID for example, and then explicitly fsync it, we end up not
logging the inode at all despite returning success to user space, which
results in the attribute being lost if a power failure happens after
the fsync.
Sample reproducer:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/dir
$ chown 6007:6007 /mnt/dir
$ sync
$ chown 9003:9003 /mnt/dir
$ touch /mnt/dir/file
$ xfs_io -c fsync /mnt/dir/file
# fsync our directory after fsync'ing the new file, should persist the
# new values for the uid and gid.
$ xfs_io -c fsync /mnt/dir
<power failure>
$ mount /dev/sdb /mnt
$ stat -c %u:%g /mnt/dir
6007:6007
--> should be 9003:9003, the uid and gid were not persisted, despite
the explicit fsync on the directory prior to the power failure
Fix this by not updating the logged_trans field of ancestor inodes when
logging an inode, since we have not logged them. Let only future calls to
btrfs_log_inode() to mark inodes as logged.
This could be triggered by my recent fsync fuzz tester for fstests, for
which an fstests patch exists titled "fstests: generic, fsync fuzz tester
with fsstress".
Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes")
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>
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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: 7237f1833601d ("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>
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commit ebb929060aeb162417b4c1307e63daee47b208d9 upstream.
When we are doing a full fsync (bit BTRFS_INODE_NEEDS_FULL_SYNC set) of a
file that has holes and has file extent items spanning two or more leafs,
we can end up falling to back to a full transaction commit due to a logic
bug that leads to failure to insert a duplicate file extent item that is
meant to represent a hole between the last file extent item of a leaf and
the first file extent item in the next leaf. The failure (EEXIST error)
leads to a transaction commit (as most errors when logging an inode do).
For example, we have the two following leafs:
Leaf N:
-----------------------------------------------
| ..., ..., ..., (257, FILE_EXTENT_ITEM, 64K) |
-----------------------------------------------
The file extent item at the end of leaf N has a length of 4Kb,
representing the file range from 64K to 68K - 1.
Leaf N + 1:
-----------------------------------------------
| (257, FILE_EXTENT_ITEM, 72K), ..., ..., ... |
-----------------------------------------------
The file extent item at the first slot of leaf N + 1 has a length of
4Kb too, representing the file range from 72K to 76K - 1.
During the full fsync path, when we are at tree-log.c:copy_items() with
leaf N as a parameter, after processing the last file extent item, that
represents the extent at offset 64K, we take a look at the first file
extent item at the next leaf (leaf N + 1), and notice there's a 4K hole
between the two extents, and therefore we insert a file extent item
representing that hole, starting at file offset 68K and ending at offset
72K - 1. However we don't update the value of *last_extent, which is used
to represent the end offset (plus 1, non-inclusive end) of the last file
extent item inserted in the log, so it stays with a value of 68K and not
with a value of 72K.
Then, when copy_items() is called for leaf N + 1, because the value of
*last_extent is smaller then the offset of the first extent item in the
leaf (68K < 72K), we look at the last file extent item in the previous
leaf (leaf N) and see it there's a 4K gap between it and our first file
extent item (again, 68K < 72K), so we decide to insert a file extent item
representing the hole, starting at file offset 68K and ending at offset
72K - 1, this insertion will fail with -EEXIST being returned from
btrfs_insert_file_extent() because we already inserted a file extent item
representing a hole for this offset (68K) in the previous call to
copy_items(), when processing leaf N.
The -EEXIST error gets propagated to the fsync callback, btrfs_sync_file(),
which falls back to a full transaction commit.
Fix this by adjusting *last_extent after inserting a hole when we had to
look at the next leaf.
Fixes: 4ee3fad34a9c ("Btrfs: fix fsync after hole punching when using no-holes feature")
Cc: stable@vger.kernel.org # 4.14+
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>
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commit 2cc8334270e281815c3850c3adea363c51f21e0d upstream.
When Filipe added the recursive directory logging stuff in
2f2ff0ee5e430 ("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>
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commit bf504110bc8aa05df48b0e5f0aa84bfb81e0574b upstream.
If we do a shrinking truncate against an inode which is already present
in the respective log tree and then rename it, as part of logging the new
name we end up logging an inode item that reflects the old size of the
file (the one which we previously logged) and not the new smaller size.
The decision to preserve the size previously logged was added by commit
1a4bcf470c886b ("Btrfs: fix fsync data loss after adding hard link to
inode") in order to avoid data loss after replaying the log. However that
decision is only needed for the case the logged inode size is smaller then
the current size of the inode, as explained in that commit's change log.
If the current size of the inode is smaller then the previously logged
size, we know a shrinking truncate happened and therefore need to use
that smaller size.
Example to trigger the problem:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ xfs_io -f -c "pwrite -S 0xab 0 8000" /mnt/foo
$ xfs_io -c "fsync" /mnt/foo
$ xfs_io -c "truncate 3000" /mnt/foo
$ mv /mnt/foo /mnt/bar
$ xfs_io -c "fsync" /mnt/bar
<power failure>
$ mount /dev/sdb /mnt
$ od -t x1 -A d /mnt/bar
0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab
*
0008000
Once we rename the file, we log its name (and inode item), and because
the inode was already logged before in the current transaction, we log it
with a size of 8000 bytes because that is the size we previously logged
(with the first fsync). As part of the rename, besides logging the inode,
we do also sync the log, which is done since commit d4682ba03ef618
("Btrfs: sync log after logging new name"), so the next fsync against our
inode is effectively a no-op, since no new changes happened since the
rename operation. Even if did not sync the log during the rename
operation, the same problem (fize size of 8000 bytes instead of 3000
bytes) would be visible after replaying the log if the log ended up
getting synced to disk through some other means, such as for example by
fsyncing some other modified file. In the example above the fsync after
the rename operation is there just because not every filesystem may
guarantee logging/journalling the inode (and syncing the log/journal)
during the rename operation, for example it is needed for f2fs, but not
for ext4 and xfs.
Fix this scenario by, when logging a new name (which is triggered by
rename and link operations), using the current size of the inode instead
of the previously logged inode size.
A test case for fstests follows soon.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202695
CC: stable@vger.kernel.org # 4.4+
Reported-by: Seulbae Kim <seulbae@gatech.edu>
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 41bd60676923822de1df2c50b3f9a10171f4338a upstream.
The log tree has a long standing problem that when a file is fsync'ed we
only check for new ancestors, created in the current transaction, by
following only the hard link for which the fsync was issued. We follow the
ancestors using the VFS' dget_parent() API. This means that if we create a
new link for a file in a directory that is new (or in an any other new
ancestor directory) and then fsync the file using an old hard link, we end
up not logging the new ancestor, and on log replay that new hard link and
ancestor do not exist. In some cases, involving renames, the file will not
exist at all.
Example:
mkfs.btrfs -f /dev/sdb
mount /dev/sdb /mnt
mkdir /mnt/A
touch /mnt/foo
ln /mnt/foo /mnt/A/bar
xfs_io -c fsync /mnt/foo
<power failure>
In this example after log replay only the hard link named 'foo' exists
and directory A does not exist, which is unexpected. In other major linux
filesystems, such as ext4, xfs and f2fs for example, both hard links exist
and so does directory A after mounting again the filesystem.
Checking if any new ancestors are new and need to be logged was added in
2009 by commit 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes"),
however only for the ancestors of the hard link (dentry) for which the
fsync was issued, instead of checking for all ancestors for all of the
inode's hard links.
So fix this by tracking the id of the last transaction where a hard link
was created for an inode and then on fsync fallback to a full transaction
commit when an inode has more than one hard link and at least one new hard
link was created in the current transaction. This is the simplest solution
since this is not a common use case (adding frequently hard links for
which there's an ancestor created in the current transaction and then
fsync the file). In case it ever becomes a common use case, a solution
that consists of iterating the fs/subvol btree for each hard link and
check if any ancestor is new, could be implemented.
This solves many unexpected scenarios reported by Jayashree Mohan and
Vijay Chidambaram, and for which there is a new test case for fstests
under review.
Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes")
CC: stable@vger.kernel.org # 4.4+
Reported-by: Vijay Chidambaram <vvijay03@gmail.com>
Reported-by: Jayashree Mohan <jayashree2912@gmail.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 4ee3fad34a9cc2cf33303dfbd0cf554248651c86 upstream.
When we have the no-holes mode enabled and fsync a file after punching a
hole in it, we can end up not logging the whole hole range in the log tree.
This happens if the file has extent items that span more than one leaf and
we punch a hole that covers a range that starts in a leaf but does not go
beyond the offset of the first extent in the next leaf.
Example:
$ mkfs.btrfs -f -O no-holes -n 65536 /dev/sdb
$ mount /dev/sdb /mnt
$ for ((i = 0; i <= 831; i++)); do
offset=$((i * 2 * 256 * 1024))
xfs_io -f -c "pwrite -S 0xab -b 256K $offset 256K" \
/mnt/foobar >/dev/null
done
$ sync
# We now have 2 leafs in our filesystem fs tree, the first leaf has an
# item corresponding the extent at file offset 216530944 and the second
# leaf has a first item corresponding to the extent at offset 217055232.
# Now we punch a hole that partially covers the range of the extent at
# offset 216530944 but does go beyond the offset 217055232.
$ xfs_io -c "fpunch $((216530944 + 128 * 1024 - 4000)) 256K" /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
<power fail>
# mount to replay the log
$ mount /dev/sdb /mnt
# Before this patch, only the subrange [216658016, 216662016[ (length of
# 4000 bytes) was logged, leaving an incorrect file layout after log
# replay.
Fix this by checking if there is a hole between the last extent item that
we processed and the first extent item in the next leaf, and if there is
one, log an explicit hole extent item.
Fixes: 16e7549f045d ("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: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit c495144bc6962186feae31d687596d2472000e45 upstream.
We're getting a lockdep splat because we take the dio_sem under the
log_mutex. What we really need is to protect fsync() from logging an
extent map for an extent we never waited on higher up, so just guard the
whole thing with dio_sem.
======================================================
WARNING: possible circular locking dependency detected
4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Not tainted
------------------------------------------------------
aio-dio-invalid/30928 is trying to acquire lock:
0000000092621cfd (&mm->mmap_sem){++++}, at: get_user_pages_unlocked+0x5a/0x1e0
but task is already holding lock:
00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #5 (&ei->dio_sem){++++}:
lock_acquire+0xbd/0x220
down_write+0x51/0xb0
btrfs_log_changed_extents+0x80/0xa40
btrfs_log_inode+0xbaf/0x1000
btrfs_log_inode_parent+0x26f/0xa80
btrfs_log_dentry_safe+0x50/0x70
btrfs_sync_file+0x357/0x540
do_fsync+0x38/0x60
__ia32_sys_fdatasync+0x12/0x20
do_fast_syscall_32+0x9a/0x2f0
entry_SYSENTER_compat+0x84/0x96
-> #4 (&ei->log_mutex){+.+.}:
lock_acquire+0xbd/0x220
__mutex_lock+0x86/0xa10
btrfs_record_unlink_dir+0x2a/0xa0
btrfs_unlink+0x5a/0xc0
vfs_unlink+0xb1/0x1a0
do_unlinkat+0x264/0x2b0
do_fast_syscall_32+0x9a/0x2f0
entry_SYSENTER_compat+0x84/0x96
-> #3 (sb_internal#2){.+.+}:
lock_acquire+0xbd/0x220
__sb_start_write+0x14d/0x230
start_transaction+0x3e6/0x590
btrfs_evict_inode+0x475/0x640
evict+0xbf/0x1b0
btrfs_run_delayed_iputs+0x6c/0x90
cleaner_kthread+0x124/0x1a0
kthread+0x106/0x140
ret_from_fork+0x3a/0x50
-> #2 (&fs_info->cleaner_delayed_iput_mutex){+.+.}:
lock_acquire+0xbd/0x220
__mutex_lock+0x86/0xa10
btrfs_alloc_data_chunk_ondemand+0x197/0x530
btrfs_check_data_free_space+0x4c/0x90
btrfs_delalloc_reserve_space+0x20/0x60
btrfs_page_mkwrite+0x87/0x520
do_page_mkwrite+0x31/0xa0
__handle_mm_fault+0x799/0xb00
handle_mm_fault+0x7c/0xe0
__do_page_fault+0x1d3/0x4a0
async_page_fault+0x1e/0x30
-> #1 (sb_pagefaults){.+.+}:
lock_acquire+0xbd/0x220
__sb_start_write+0x14d/0x230
btrfs_page_mkwrite+0x6a/0x520
do_page_mkwrite+0x31/0xa0
__handle_mm_fault+0x799/0xb00
handle_mm_fault+0x7c/0xe0
__do_page_fault+0x1d3/0x4a0
async_page_fault+0x1e/0x30
-> #0 (&mm->mmap_sem){++++}:
__lock_acquire+0x42e/0x7a0
lock_acquire+0xbd/0x220
down_read+0x48/0xb0
get_user_pages_unlocked+0x5a/0x1e0
get_user_pages_fast+0xa4/0x150
iov_iter_get_pages+0xc3/0x340
do_direct_IO+0xf93/0x1d70
__blockdev_direct_IO+0x32d/0x1c20
btrfs_direct_IO+0x227/0x400
generic_file_direct_write+0xcf/0x180
btrfs_file_write_iter+0x308/0x58c
aio_write+0xf8/0x1d0
io_submit_one+0x3a9/0x620
__ia32_compat_sys_io_submit+0xb2/0x270
do_int80_syscall_32+0x5b/0x1a0
entry_INT80_compat+0x88/0xa0
other info that might help us debug this:
Chain exists of:
&mm->mmap_sem --> &ei->log_mutex --> &ei->dio_sem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ei->dio_sem);
lock(&ei->log_mutex);
lock(&ei->dio_sem);
lock(&mm->mmap_sem);
*** DEADLOCK ***
1 lock held by aio-dio-invalid/30928:
#0: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400
stack backtrace:
CPU: 0 PID: 30928 Comm: aio-dio-invalid Not tainted 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Call Trace:
dump_stack+0x7c/0xbb
print_circular_bug.isra.37+0x297/0x2a4
check_prev_add.constprop.45+0x781/0x7a0
? __lock_acquire+0x42e/0x7a0
validate_chain.isra.41+0x7f0/0xb00
__lock_acquire+0x42e/0x7a0
lock_acquire+0xbd/0x220
? get_user_pages_unlocked+0x5a/0x1e0
down_read+0x48/0xb0
? get_user_pages_unlocked+0x5a/0x1e0
get_user_pages_unlocked+0x5a/0x1e0
get_user_pages_fast+0xa4/0x150
iov_iter_get_pages+0xc3/0x340
do_direct_IO+0xf93/0x1d70
? __alloc_workqueue_key+0x358/0x490
? __blockdev_direct_IO+0x14b/0x1c20
__blockdev_direct_IO+0x32d/0x1c20
? btrfs_run_delalloc_work+0x40/0x40
? can_nocow_extent+0x490/0x490
? kvm_clock_read+0x1f/0x30
? can_nocow_extent+0x490/0x490
? btrfs_run_delalloc_work+0x40/0x40
btrfs_direct_IO+0x227/0x400
? btrfs_run_delalloc_work+0x40/0x40
generic_file_direct_write+0xcf/0x180
btrfs_file_write_iter+0x308/0x58c
aio_write+0xf8/0x1d0
? kvm_clock_read+0x1f/0x30
? __might_fault+0x3e/0x90
io_submit_one+0x3a9/0x620
? io_submit_one+0xe5/0x620
__ia32_compat_sys_io_submit+0xb2/0x270
do_int80_syscall_32+0x5b/0x1a0
entry_INT80_compat+0x88/0xa0
CC: stable@vger.kernel.org # 4.14+
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 7ed586d0a8241e81d58c656c5b315f781fa6fc97 upstream.
When using the NO_HOLES feature and logging a regular file, we were
expecting that if we find an inline extent, that either its size in RAM
(uncompressed and unenconded) matches the size of the file or if it does
not, that it matches the sector size and it represents compressed data.
This assertion does not cover a case where the length of the inline extent
is smaller than the sector size and also smaller the file's size, such
case is possible through fallocate. Example:
$ mkfs.btrfs -f -O no-holes /dev/sdb
$ mount /dev/sdb /mnt
$ xfs_io -f -c "pwrite -S 0xb60 0 21" /mnt/foobar
$ xfs_io -c "falloc 40 40" /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
In the above example we trigger the assertion because the inline extent's
length is 21 bytes while the file size is 80 bytes. The fallocate() call
merely updated the file's size and did not touch the existing inline
extent, as expected.
So fix this by adjusting the assertion so that an inline extent length
smaller than the file size is valid if the file size is smaller than the
filesystem's sector size.
A test case for fstests follows soon.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: a89ca6f24ffe ("Btrfs: fix fsync after truncate when no_holes feature is enabled")
CC: stable@vger.kernel.org # 4.14+
Link: https://lore.kernel.org/linux-btrfs/CAE5jQCfRSBC7n4pUTFJcmHh109=gwyT9mFkCOL+NKfzswmR=_Q@mail.gmail.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 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>
|
|
commit f2d72f42d5fa3bf33761d9e47201745f624fcff5 upstream.
When replaying a log which contains a tmpfile (which necessarily has a
link count of 0) we end up calling inc_nlink(), at
fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like
the following:
[195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40
[195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1
[195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
[195191.943726] RIP: 0010:inc_nlink+0x33/0x40
[195191.943728] RSP: 0018:ffffb96e425e3870 EFLAGS: 00010246
[195191.943730] RAX: 0000000000000000 RBX: ffff8c0d1e6af4f0 RCX: 0000000000000006
[195191.943731] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8c0d1e6af4f0
[195191.943731] RBP: 0000000000000097 R08: 0000000000000001 R09: 0000000000000000
[195191.943732] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb96e425e3a60
[195191.943733] R13: ffff8c0d10cff0c8 R14: ffff8c0d0d515348 R15: ffff8c0d78a1b3f8
[195191.943735] FS: 00007f570ee24480(0000) GS:ffff8c0dfb200000(0000) knlGS:0000000000000000
[195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[195191.943737] CR2: 00005593286277c8 CR3: 00000000bb8f2006 CR4: 00000000003606f0
[195191.943739] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[195191.943740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[195191.943741] Call Trace:
[195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs]
[195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs]
[195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70
[195191.943825] walk_log_tree+0xae/0x1d0 [btrfs]
[195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs]
[195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs]
[195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs]
[195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs]
[195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70
[195191.943899] ? pcpu_alloc+0x55b/0x7c0
[195191.943906] ? mount_fs+0x3b/0x140
[195191.943908] mount_fs+0x3b/0x140
[195191.943912] ? __init_waitqueue_head+0x36/0x50
[195191.943916] vfs_kern_mount+0x62/0x160
[195191.943927] btrfs_mount+0x134/0x890 [btrfs]
[195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70
[195191.943938] ? pcpu_alloc+0x55b/0x7c0
[195191.943943] ? mount_fs+0x3b/0x140
[195191.943952] ? btrfs_remount+0x570/0x570 [btrfs]
[195191.943954] mount_fs+0x3b/0x140
[195191.943956] ? __init_waitqueue_head+0x36/0x50
[195191.943960] vfs_kern_mount+0x62/0x160
[195191.943963] do_mount+0x1f9/0xd40
[195191.943967] ? memdup_user+0x4b/0x70
[195191.943971] ksys_mount+0x7e/0xd0
[195191.943974] __x64_sys_mount+0x21/0x30
[195191.943977] do_syscall_64+0x60/0x1b0
[195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[195191.943983] RIP: 0033:0x7f570e4e524a
[195191.943986] RSP: 002b:00007ffd83589478 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[195191.943989] RAX: ffffffffffffffda RBX: 0000563f335b2060 RCX: 00007f570e4e524a
[195191.943990] RDX: 0000563f335b2240 RSI: 0000563f335b2280 RDI: 0000563f335b2260
[195191.943992] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020
[195191.943993] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000563f335b2260
[195191.943994] R13: 0000563f335b2240 R14: 0000000000000000 R15: 00000000ffffffff
[195191.944002] irq event stamp: 8688
[195191.944010] hardirqs last enabled at (8687): [<ffffffff9cb004c3>] console_unlock+0x503/0x640
[195191.944012] hardirqs last disabled at (8688): [<ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
[195191.944018] softirqs last enabled at (8638): [<ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150
[195191.944020] softirqs last disabled at (8634): [<ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60
[195191.944022] ---[ end trace 5d6e873a9a0b811a ]---
This happens because the inode does not have the flag I_LINKABLE set,
which is a runtime only flag, not meant to be persisted, set when the
inode is created through open(2) if the flag O_EXCL is not passed to it.
Except for the warning, there are no other consequences (like corruptions
or metadata inconsistencies).
Since it's pointless to replay a tmpfile as it would be deleted in a
later phase of the log replay procedure (it has a link count of 0), fix
this by not logging tmpfiles and if a tmpfile is found in a log (created
by a kernel without this change), skip the replay of the inode.
A test case for fstests follows soon.
Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay")
CC: stable@vger.kernel.org # 4.18+
Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/
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 374b0e2d6ba5da7fd1cadb3247731ff27d011f6f upstream.
When we hit an I/O error in free_log_tree->walk_log_tree during file system
shutdown we can crash due to there not being a valid transaction handle.
Use btrfs_handle_fs_error when there's no transaction handle to use.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000060
IP: free_log_tree+0xd2/0x140 [btrfs]
PGD 0 P4D 0
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
Modules linked in: <modules>
CPU: 2 PID: 23544 Comm: umount Tainted: G W 4.12.14-kvmsmall #9 SLE15 (unreleased)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
task: ffff96bfd3478880 task.stack: ffffa7cf40d78000
RIP: 0010:free_log_tree+0xd2/0x140 [btrfs]
RSP: 0018:ffffa7cf40d7bd10 EFLAGS: 00010282
RAX: 00000000fffffffb RBX: 00000000fffffffb RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffff96c02f07d4c8 RDI: 0000000000000282
RBP: ffff96c013cf1000 R08: ffff96c02f07d4c8 R09: ffff96c02f07d4d0
R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
R13: ffff96c005e800c0 R14: ffffa7cf40d7bdb8 R15: 0000000000000000
FS: 00007f17856bcfc0(0000) GS:ffff96c03f600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 0000000045ed6002 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? wait_for_writer+0xb0/0xb0 [btrfs]
btrfs_free_log+0x17/0x30 [btrfs]
btrfs_drop_and_free_fs_root+0x9a/0xe0 [btrfs]
btrfs_free_fs_roots+0xc0/0x130 [btrfs]
? wait_for_completion+0xf2/0x100
close_ctree+0xea/0x2e0 [btrfs]
? kthread_stop+0x161/0x260
generic_shutdown_super+0x6c/0x120
kill_anon_super+0xe/0x20
btrfs_kill_super+0x13/0x100 [btrfs]
deactivate_locked_super+0x3f/0x70
cleanup_mnt+0x3b/0x70
task_work_run+0x78/0x90
exit_to_usermode_loop+0x77/0xa6
do_syscall_64+0x1c5/0x1e0
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f1784f90827
RSP: 002b:00007ffdeeb03118 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000556a60c62970 RCX: 00007f1784f90827
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556a60c62b50
RBP: 0000000000000000 R08: 0000000000000005 R09: 00000000ffffffff
R10: 0000556a60c63900 R11: 0000000000000246 R12: 0000556a60c62b50
R13: 00007f17854a81c4 R14: 0000000000000000 R15: 0000000000000000
RIP: free_log_tree+0xd2/0x140 [btrfs] RSP: ffffa7cf40d7bd10
CR2: 0000000000000060
Fixes: 681ae50917df9 ("Btrfs: cleanup reserved space when freeing tree log on error")
CC: <stable@vger.kernel.org> # v3.13
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ 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>
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commit 31d11b83b96faaee4bb514d375a09489117c3e8d upstream.
In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size
after fsync log replay"), on fsync, we started to always log all prealloc
extents beyond an inode's i_size in order to avoid losing them after a
power failure. However under some cases this can lead to the log replay
code to create duplicate extent items, with different lengths, in the
extent tree. That happens because, as of that commit, we can now log
extent items based on extent maps that are not on the "modified" list
of extent maps of the inode's extent map tree. Logging extent items based
on extent maps is used during the fast fsync path to save time and for
this to work reliably it requires that the extent maps are not merged
with other adjacent extent maps - having the extent maps in the list
of modified extents gives such guarantee.
Consider the following example, captured during a long run of fsstress,
which illustrates this problem.
We have inode 271, in the filesystem tree (root 5), for which all of the
following operations and discussion apply to.
A buffered write starts at offset 312391 with a length of 933471 bytes
(end offset at 1245862). At this point we have, for this inode, the
following extent maps with the their field values:
em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 376832, block_start 1106399232,
block_len 376832, orig_block_len 376832
em C, start 417792, orig_start 417792, len 782336, block_start
18446744073709551613, block_len 0, orig_block_len 0
em D, start 1200128, orig_start 1200128, len 835584, block_start
1106776064, block_len 835584, orig_block_len 835584
em E, start 2035712, orig_start 2035712, len 245760, block_start
1107611648, block_len 245760, orig_block_len 245760
Extent map A corresponds to a hole and extent maps D and E correspond to
preallocated extents.
Extent map D ends where extent map E begins (1106776064 + 835584 =
1107611648), but these extent maps were not merged because they are in
the inode's list of modified extent maps.
An fsync against this inode is made, which triggers the fast path
(BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback
of the data previously written using buffered IO, and when the respective
ordered extent finishes, btrfs_drop_extents() is called against the
(aligned) range 311296..1249279. This causes a split of extent map D at
btrfs_drop_extent_cache(), replacing extent map D with a new extent map
D', also added to the list of modified extents, with the following
values:
em D', start 1249280, orig_start of 1200128,
block_start 1106825216 (= 1106776064 + 1249280 - 1200128),
orig_block_len 835584,
block_len 786432 (835584 - (1249280 - 1200128))
Then, during the fast fsync, btrfs_log_changed_extents() is called and
extent maps D' and E are removed from the list of modified extents. The
flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged
clear_em_logging() is called on each of them, and that makes extent map E
to be merged with extent map D' (try_merge_map()), resulting in D' being
deleted and E adjusted to:
em E, start 1249280, orig_start 1200128, len 1032192,
block_start 1106825216, block_len 1032192,
orig_block_len 245760
A direct IO write at offset 1847296 and length of 360448 bytes (end offset
at 2207744) starts, and at that moment the following extent maps exist for
our inode:
em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 270336, block_start 1106399232,
block_len 270336, orig_block_len 376832
em C, start 311296, orig_start 311296, len 937984, block_start 1112842240,
block_len 937984, orig_block_len 937984
em E (prealloc), start 1249280, orig_start 1200128, len 1032192,
block_start 1106825216, block_len 1032192, orig_block_len 245760
The dio write results in drop_extent_cache() being called twice. The first
time for a range that starts at offset 1847296 and ends at offset 2035711
(length of 188416), which results in a double split of extent map E,
replacing it with two new extent maps:
em F, start 1249280, orig_start 1200128, block_start 1106825216,
block_len 598016, orig_block_len 598016
em G, start 2035712, orig_start 1200128, block_start 1107611648,
block_len 245760, orig_block_len 1032192
It also creates a new extent map that represents a part of the requested
IO (through create_io_em()):
em H, start 1847296, len 188416, block_start 1107423232, block_len 188416
The second call to drop_extent_cache() has a range with a start offset of
2035712 and end offset of 2207743 (length of 172032). This leads to
replacing extent map G with a new extent map I with the following values:
em I, start 2207744, orig_start 1200128, block_start 1107783680,
block_len 73728, orig_block_len 1032192
It also creates a new extent map that represents the second part of the
requested IO (through create_io_em()):
em J, start 2035712, len 172032, block_start 1107611648, block_len 172032
The dio write set the inode's i_size to 2207744 bytes.
After the dio write the inode has the following extent maps:
em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 270336, block_start 1106399232,
block_len 270336, orig_block_len 376832
em C, start 311296, orig_start 311296, len 937984, block_start 1112842240,
block_len 937984, orig_block_len 937984
em F, start 1249280, orig_start 1200128, len 598016,
block_start 1106825216, block_len 598016, orig_block_len 598016
em H, start 1847296, orig_start 1200128, len 188416,
block_start 1107423232, block_len 188416, orig_block_len 835584
em J, start 2035712, orig_start 2035712, len 172032,
block_start 1107611648, block_len 172032, orig_block_len 245760
em I, start 2207744, orig_start 1200128, len 73728,
block_start 1107783680, block_len 73728, orig_block_len 1032192
Now do some change to the file, like adding a xattr for example and then
fsync it again. This triggers a fast fsync path, and as of commit
471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync
log replay"), we use the extent map I to log a file extent item because
it's a prealloc extent and it starts at an offset matching the inode's
i_size. However when we log it, we create a file extent item with a value
for the disk byte location that is wrong, as can be seen from the
following output of "btrfs inspect-internal dump-tree":
item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53
generation 22 type 2 (prealloc)
prealloc data disk byte 1106776064 nr 1032192
prealloc data offset 1007616 nr 73728
Here the disk byte value corresponds to calculation based on some fields
from the extent map I:
1106776064 = block_start (1107783680) - 1007616 (extent_offset)
extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616
The disk byte value of 1106776064 clashes with disk byte values of the
file extent items at offsets 1249280 and 1847296 in the fs tree:
item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53
generation 20 type 2 (prealloc)
prealloc data disk byte 1106776064 nr 835584
prealloc data offset 49152 nr 598016
item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53
generation 20 type 1 (regular)
extent data disk byte 1106776064 nr 835584
extent data offset 647168 nr 188416 ram 835584
extent compression 0 (none)
item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53
generation 20 type 1 (regular)
extent data disk byte 1107611648 nr 245760
extent data offset 0 nr 172032 ram 245760
extent compression 0 (none)
item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53
generation 20 type 2 (prealloc)
prealloc data disk byte 1107611648 nr 245760
prealloc data offset 172032 nr 73728
Instead of the disk byte value of 1106776064, the value of 1107611648
should have been logged. Also the data offset value should have been
172032 and not 1007616.
After a log replay we end up getting two extent items in the extent tree
with different lengths, one of 835584, which is correct and existed
before the log replay, and another one of 1032192 which is wrong and is
based on the logged file extent item:
item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53
refs 2 gen 15 flags DATA
extent data backref root 5 objectid 271 offset 1200128 count 2
item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53
refs 1 gen 22 flags DATA
extent data backref root 5 objectid 271 offset 1200128 count 1
Obviously this leads to many problems and a filesystem check reports many
errors:
(...)
checking extents
Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1
extent item 1106776064 has multiple extent items
ref mismatch on [1106776064 835584] extent item 2, found 3
Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680
Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree
Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70
Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192
backpointer mismatch on [1106776064 835584]
checking free space cache
block group 1103101952 has wrong amount of free space
failed to load free space cache for block group 1103101952
checking fs roots
(...)
So fix this by logging the prealloc extents beyond the inode's i_size
based on searches in the subvolume tree instead of the extent maps.
Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ 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: 16e7549f045d ("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>
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[ 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: e02119d5a7b4 ("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>
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[ 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: e02119d5a7b4 ("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>
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[ Upstream commit 471d557afed155b85da237ec46c549f443eeb5de ]
Currently if we allocate extents beyond an inode's i_size (through the
fallocate system call) and then fsync the file, we log the extents but
after a power failure we replay them and then immediately drop them.
This behaviour happens since about 2009, commit c71bf099abdd ("Btrfs:
Avoid orphan inodes cleanup while replaying log"), because it marks
the inode as an orphan instead of dropping any extents beyond i_size
before replaying logged extents, so after the log replay, and while
the mount operation is still ongoing, we find the inode marked as an
orphan and then perform a truncation (drop extents beyond the inode's
i_size). Because the processing of orphan inodes is still done
right after replaying the log and before the mount operation finishes,
the intention of that commit does not make any sense (at least as
of today). However reverting that behaviour is not enough, because
we can not simply discard all extents beyond i_size and then replay
logged extents, because we risk dropping extents beyond i_size created
in past transactions, for example:
add prealloc extent beyond i_size
fsync - clears the flag BTRFS_INODE_NEEDS_FULL_SYNC from the inode
transaction commit
add another prealloc extent beyond i_size
fsync - triggers the fast fsync path
power failure
In that scenario, we would drop the first extent and then replay the
second one. To fix this just make sure that all prealloc extents
beyond i_size are logged, and if we find too many (which is far from
a common case), fallback to a full transaction commit (like we do when
logging regular extents in the fast fsync path).
Trivial reproducer:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ xfs_io -f -c "pwrite -S 0xab 0 256K" /mnt/foo
$ sync
$ xfs_io -c "falloc -k 256K 1M" /mnt/foo
$ xfs_io -c "fsync" /mnt/foo
<power failure>
# mount to replay log
$ mount /dev/sdb /mnt
# at this point the file only has one extent, at offset 0, size 256K
A test case for fstests follows soon, covering multiple scenarios that
involve adding prealloc extents with previous shrinking truncates and
without such truncates.
Fixes: c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log")
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>
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[ Upstream commit 9a6509c4daa91400b52a5fd541a5521c649a8fea ]
If in the same transaction we rename a special file (fifo, character/block
device or symbolic link), create a hard link for it having its old name
then sync the log, we will end up with a log that can not be replayed and
at when attempting to replay it, an EEXIST error is returned and mounting
the filesystem fails. Example scenario:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ mkdir /mnt/testdir
$ mkfifo /mnt/testdir/foo
# Make sure everything done so far is durably persisted.
$ sync
# Create some unrelated file and fsync it, this is just to create a log
# tree. The file must be in the same directory as our special file.
$ touch /mnt/testdir/f1
$ xfs_io -c "fsync" /mnt/testdir/f1
# Rename our special file and then create a hard link with its old name.
$ mv /mnt/testdir/foo /mnt/testdir/bar
$ ln /mnt/testdir/bar /mnt/testdir/foo
# Create some other unrelated file and fsync it, this is just to persist
# the log tree which was modified by the previous rename and link
# operations. Alternatively we could have modified file f1 and fsync it.
$ touch /mnt/f2
$ xfs_io -c "fsync" /mnt/f2
<power failure>
$ mount /dev/sdc /mnt
mount: mount /dev/sdc on /mnt failed: File exists
This happens because when both the log tree and the subvolume's tree have
an entry in the directory "testdir" with the same name, that is, there
is one key (258 INODE_REF 257) in the subvolume tree and another one in
the log tree (where 258 is the inode number of our special file and 257
is the inode for directory "testdir"). Only the data of those two keys
differs, in the subvolume tree the index field for inode reference has
a value of 3 while the log tree it has a value of 5. Because the same key
exists in both trees, but have different index, the log replay fails with
an -EEXIST error when attempting to replay the inode reference from the
log tree.
Fix this by setting the last_unlink_trans field of the inode (our special
file) to the current transaction id when a hard link is created, as this
forces logging the parent directory inode, solving the conflict at log
replay time.
A new generic test case for fstests was also submitted.
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>
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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: 36283bf777d9 ("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>
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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: f32e48e92596 ("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>
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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>
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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: 681ae50917df ("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>
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[ Upstream commit ebb70442cdd4872260c2415929c456be3562da82 ]
Xfstests btrfs/146 revealed this corruption,
[ 58.138831] Buffer I/O error on dev dm-0, logical block 2621424, async page read
[ 58.151233] BTRFS error (device sdf): bdev /dev/mapper/error-test errs: wr 1, rd 0, flush 0, corrupt 0, gen 0
[ 58.152403] list_add corruption. prev->next should be next (ffff88005e6775d8), but was ffffc9000189be88. (prev=ffffc9000189be88).
[ 58.153518] ------------[ cut here ]------------
[ 58.153892] WARNING: CPU: 1 PID: 1287 at lib/list_debug.c:31 __list_add_valid+0x169/0x1f0
...
[ 58.157379] RIP: 0010:__list_add_valid+0x169/0x1f0
...
[ 58.161956] Call Trace:
[ 58.162264] btrfs_log_inode_parent+0x5bd/0xfb0 [btrfs]
[ 58.163583] btrfs_log_dentry_safe+0x60/0x80 [btrfs]
[ 58.164003] btrfs_sync_file+0x4c2/0x6f0 [btrfs]
[ 58.164393] vfs_fsync_range+0x5f/0xd0
[ 58.164898] do_fsync+0x5a/0x90
[ 58.165170] SyS_fsync+0x10/0x20
[ 58.165395] entry_SYSCALL_64_fastpath+0x1f/0xbe
...
It turns out that we could record btrfs_log_ctx:io_err in
log_one_extents when IO fails, but make log_one_extents() return '0'
instead of -EIO, so the IO error is not acknowledged by the callers,
i.e. btrfs_log_inode_parent(), which would remove btrfs_log_ctx:list
from list head 'root->log_ctxs'. Since btrfs_log_ctx is allocated
from stack memory, it'd get freed with a object alive on the
list. then a future list_add will throw the above warning.
This returns the correct error in the above case.
Jeff also reported this while testing against his fsync error
patch set[1].
[1]: https://www.spinics.net/lists/linux-btrfs/msg65308.html
"btrfs list corruption and soft lockups while testing writeback error handling"
Fixes: 8407f553268a4611f254 ("Btrfs: fix data corruption after fast fsync and writeback error")
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
Amir reported a bug discovered by his cleaned up version of my
dm-log-writes xfstests where we were missing csums at certain replay
points. This is because fsx was doing an msync(), which essentially
fsync()'s a specific range of a file. We will log all modified extents,
but only search for the checksums in the range we are being asked to
sync. We cannot simply log the extents in the range we're being asked
because we are logging the inode item as it is currently, which if it
has had a i_size update before the msync means we will miss extents when
replaying. We could possibly get around this by marking the inode with
the transaction that extended the i_size to see if we have this case,
but this would be racy and we'd have to lock the whole range of the
inode to make sure we didn't have an ordered extent outside of our range
that was in the middle of completing.
Fix this simply by keeping track of the modified extents range and
logging the csums for the entire range of extents that we are logging.
This makes the xfstest pass.
Reported-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
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>
|
|
When logging an inode in full mode that has an inline compressed extent
that represents a range with a size matching the sector size (currently
the same as the page size), has a trailing hole and the no-holes feature
is enabled, we end up failing an assertion leading to a trace like the
following:
[141812.031528] assertion failed: len == i_size, file: fs/btrfs/tree-log.c, line: 4453
[141812.033069] ------------[ cut here ]------------
[141812.034330] kernel BUG at fs/btrfs/ctree.h:3452!
[141812.035137] invalid opcode: 0000 [#1] PREEMPT SMP
[141812.035932] Modules linked in: btrfs dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio dm_flakey dm_mod dax ppdev evdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 tpm_tis psmouse crypto_simd parport_pc sg pcspkr tpm_tis_core cryptd parport serio_raw glue_helper tpm i2c_piix4 i2c_core button sunrpc loop autofs4 ext4 crc16 jbd2 mbcache raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod ata_generic virtio_scsi ata_piix floppy crc32c_intel libata scsi_mod virtio_pci virtio_ring e1000 virtio [last unloaded: btrfs]
[141812.036790] CPU: 3 PID: 845 Comm: fdm-stress Tainted: G B W 4.12.3-btrfs-next-52+ #1
[141812.036790] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
[141812.036790] task: ffff8801e6694180 task.stack: ffffc90009004000
[141812.036790] RIP: 0010:assfail.constprop.18+0x1c/0x1e [btrfs]
[141812.036790] RSP: 0018:ffffc90009007bc0 EFLAGS: 00010282
[141812.036790] RAX: 0000000000000046 RBX: ffff88017512c008 RCX: 0000000000000001
[141812.036790] RDX: ffff88023fd95201 RSI: ffffffff8182264c RDI: 00000000ffffffff
[141812.036790] RBP: ffffc90009007bc0 R08: 0000000000000001 R09: 0000000000000001
[141812.036790] R10: 0000000000001000 R11: ffffffff82f5a0c9 R12: ffff88014e5947e8
[141812.036790] R13: 00000000000b4000 R14: ffff8801b234d008 R15: 0000000000000000
[141812.036790] FS: 00007fdba6ffd700(0000) GS:ffff88023fd80000(0000) knlGS:0000000000000000
[141812.036790] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[141812.036790] CR2: 00007fdb9c000010 CR3: 000000016efa2000 CR4: 00000000001406e0
[141812.036790] Call Trace:
[141812.036790] btrfs_log_inode+0x9f0/0xd3d [btrfs]
[141812.036790] ? __mutex_lock+0x120/0x3ce
[141812.036790] btrfs_log_inode_parent+0x224/0x685 [btrfs]
[141812.036790] ? lock_acquire+0x16b/0x1af
[141812.036790] btrfs_log_dentry_safe+0x60/0x7b [btrfs]
[141812.036790] btrfs_sync_file+0x32e/0x3f8 [btrfs]
[141812.036790] vfs_fsync_range+0x8a/0x9d
[141812.036790] vfs_fsync+0x1c/0x1e
[141812.036790] do_fsync+0x31/0x4a
[141812.036790] SyS_fdatasync+0x13/0x17
[141812.036790] entry_SYSCALL_64_fastpath+0x18/0xad
[141812.036790] RIP: 0033:0x7fdbac41a47d
[141812.036790] RSP: 002b:00007fdba6ffce30 EFLAGS: 00000293 ORIG_RAX: 000000000000004b
[141812.036790] RAX: ffffffffffffffda RBX: ffffffff81092c9f RCX: 00007fdbac41a47d
[141812.036790] RDX: 0000004cf0160a40 RSI: 0000000000000000 RDI: 0000000000000006
[141812.036790] RBP: ffffc90009007f98 R08: 0000000000000000 R09: 0000000000000010
[141812.036790] R10: 00000000000002e8 R11: 0000000000000293 R12: ffffffff8110cd90
[141812.036790] R13: ffffc90009007f78 R14: 0000000000000000 R15: 0000000000000000
[141812.036790] ? time_hardirqs_off+0x9/0x14
[141812.036790] ? trace_hardirqs_off_caller+0x1f/0xa3
[141812.036790] Code: c7 d6 61 6b a0 48 89 e5 e8 ba ef a8 e0 0f 0b 55 89 f1 48 c7 c2 6d 65 6b a0 48 89 fe 48 c7 c7 81 65 6b a0 48 89 e5 e8 9c ef a8 e0 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89
[141812.036790] RIP: assfail.constprop.18+0x1c/0x1e [btrfs] RSP: ffffc90009007bc0
[141812.084448] ---[ end trace 44e472684c7a32cc ]---
Which happens because the code that logs a trailing hole when the no-holes
feature is enabled, did not consider that a compressed inline extent can
represent a range with a size matching the sector size, in which case
expanding the inode's i_size, through a truncate operation, won't lead
to padding with zeroes the page that represents the inline extent, and
therefore the inline extent remains after the truncation.
Fix this by adapting the assertion to accept inline extents representing
data with a sector size length if, and only if, the inline extents are
compressed.
A sample and trivial reproducer (for systems with a 4K page size) for this
issue:
mkfs.btrfs -O no-holes -f /dev/sdc
mount -o compress /dev/sdc /mnt
xfs_io -f -c "pwrite -S 0xab 0 4K" /mnt/foobar
sync
xfs_io -c "truncate 32K" /mnt/foobar
xfs_io -c "fsync" /mnt/foobar
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The error return variable ret is initialized to zero and then is
checked to see if it is non-zero in the if-block that follows it.
It is therefore impossible for ret to be non-zero after the if-block
hence the check is redundant and can be removed.
Detected by CoverityScan, CID#1021040 ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We were passing an incorrect slot number to the function that validates
directory items when we are replaying xattr deletes from a log tree. The
correct slot is stored at variable 'i' and not at 'path->slots[0]', so
the call to the validation function was only correct for the first
iteration of the loop, when 'i == path->slots[0]'.
After this fix, the fstest generic/066 passes again.
Fixes: 8ee8c2d62d5f ("btrfs: Verify dir_item in replay_xattr_deletes")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
In btrfs_log_inode, btrfs_search_forward gets the buffer and then
btrfs_check_ref_name_override will read name from ref/extref for the
first time.
Call btrfs_is_name_len_valid before reading name.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
replay_xattr_deletes calls btrfs_search_slot to get buffer and reads
name.
Call verify_dir_item to check name_len in replay_xattr_deletes to avoid
reading out of boundary.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
replay_one_buffer first reads buffers and dispatches items accroding to
the item type.
In this patch, add_inode_ref handles inode_ref and inode_extref.
Then add_inode_ref calls ref_get_fields and extref_get_fields to read
ref/extref name for the first time.
So checking name_len before reading those two is fine.
add_inode_ref also calls inode_in_dir to match ref/extref in parent_dir.
The call graph includes btrfs_match_dir_item_name to read dir_item name
in the parent dir.
Checking first dir_item is not enough. Change it to verify every
dir_item while doing matches.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Originally, verify_dir_item verifies name_len of dir_item with fixed
values but not item boundary.
If corrupted name_len was not bigger than the fixed value, for example
255, the function will think the dir_item is fine. And then reading
beyond boundary will cause crash.
Example:
1. Corrupt one dir_item name_len to be 255.
2. Run 'ls -lar /mnt/test/ > /dev/null'
dmesg:
[ 48.451449] BTRFS info (device vdb1): disk space caching is enabled
[ 48.451453] BTRFS info (device vdb1): has skinny extents
[ 48.489420] general protection fault: 0000 [#1] SMP
[ 48.489571] Modules linked in: ext4 jbd2 mbcache btrfs xor raid6_pq
[ 48.489716] CPU: 1 PID: 2710 Comm: ls Not tainted 4.10.0-rc1 #5
[ 48.489853] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
[ 48.490008] task: ffff880035df1bc0 task.stack: ffffc90004800000
[ 48.490008] RIP: 0010:read_extent_buffer+0xd2/0x190 [btrfs]
[ 48.490008] RSP: 0018:ffffc90004803d98 EFLAGS: 00010202
[ 48.490008] RAX: 000000000000001b RBX: 000000000000001b RCX: 0000000000000000
[ 48.490008] RDX: ffff880079dbf36c RSI: 0005080000000000 RDI: ffff880079dbf368
[ 48.490008] RBP: ffffc90004803dc8 R08: ffff880078e8cc48 R09: ffff880000000000
[ 48.490008] R10: 0000160000000000 R11: 0000000000001000 R12: ffff880079dbf288
[ 48.490008] R13: ffff880078e8ca88 R14: 0000000000000003 R15: ffffc90004803e20
[ 48.490008] FS: 00007fef50c60800(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
[ 48.490008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 48.490008] CR2: 000055f335ac2ff8 CR3: 000000007356d000 CR4: 00000000001406e0
[ 48.490008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 48.490008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 48.490008] Call Trace:
[ 48.490008] btrfs_real_readdir+0x3b7/0x4a0 [btrfs]
[ 48.490008] iterate_dir+0x181/0x1b0
[ 48.490008] SyS_getdents+0xa7/0x150
[ 48.490008] ? fillonedir+0x150/0x150
[ 48.490008] entry_SYSCALL_64_fastpath+0x18/0xad
[ 48.490008] RIP: 0033:0x7fef5032546b
[ 48.490008] RSP: 002b:00007ffeafcdb830 EFLAGS: 00000206 ORIG_RAX: 000000000000004e
[ 48.490008] RAX: ffffffffffffffda RBX: 00007fef5061db38 RCX: 00007fef5032546b
[ 48.490008] RDX: 0000000000008000 RSI: 000055f335abaff0 RDI: 0000000000000003
[ 48.490008] RBP: 00007fef5061dae0 R08: 00007fef5061db48 R09: 0000000000000000
[ 48.490008] R10: 000055f335abafc0 R11: 0000000000000206 R12: 00007fef5061db38
[ 48.490008] R13: 0000000000008040 R14: 00007fef5061db38 R15: 000000000000270e
[ 48.490008] RIP: read_extent_buffer+0xd2/0x190 [btrfs] RSP: ffffc90004803d98
[ 48.499455] ---[ end trace 321920d8e8339505 ]---
Fix it by adding a parameter @slot and check name_len with item boundary
by calling btrfs_is_name_len_valid.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
rev
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.11
|
|
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We log holes explicitly by using file extent items, however when replaying
a log tree, if a logged file extent item corresponds to a hole and the
NO_HOLES feature is enabled we do not need to copy the file extent item
into the fs/subvolume tree, as the absence of such file extent items is
the purpose of the NO_HOLES feature. So skip the copying of file extent
items representing holes when the NO_HOLES feature is enabled.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
Unused since the helper has been split, eb used in the caller.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
write_all_supers and write_ctree_super are almost equal, the parameter
'trans' is unused so we can drop it and have just one helper.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Added but never needed.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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This goes as a separate patch because fixing that inside the patches
caused too many many conflicts.
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
