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>
If device replace entry was found on disk at mounting and its num_write_errors
stats counter has non-NULL value, then replace operation will never be
finished and -EIO error will be reported by btrfs_scrub_dev() because
this counter is never reset.
# mount -o degraded /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
# btrfs replace status /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
Started on 25.Mar 07:28:00, canceled on 25.Mar 07:28:01 at 0.0%, 40 write errs, 0 uncorr. read errs
# btrfs replace start -B 4 /dev/sdg /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
ERROR: ioctl(DEV_REPLACE_START) failed on "/media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/": Input/output error, no error
Reset num_write_errors and num_uncorrectable_read_errors counters in the
dev_replace structure before start of replacing.
Signed-off-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch adds tracepoints to the qgroup code on both the reporting side
(insert_dirty_extents) and the accounting side. Taken together it allows us
to see what qgroup operations have happened, and what their result was.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fd we pass in may not be on a btrfs file system, so don't try to do
BTRFS_I() on it. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The allocation of node could fail if the memory is too fragmented for a
given node size, practically observed with 64k.
http://article.gmane.org/gmane.comp.file-systems.btrfs/54689
Reported-and-tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
Signed-off-by: David Sterba <dsterba@suse.com>
create_pending_snapshot() will go readonly on _any_ error return from
btrfs_qgroup_inherit(). If qgroups are enabled, a user can crash their fs by
just making a snapshot and asking it to inherit from an invalid qgroup. For
example:
$ btrfs sub snap -i 1/10 /btrfs/ /btrfs/foo
Will cause a transaction abort.
Fix this by only throwing errors in btrfs_qgroup_inherit() when we know
going readonly is acceptable.
The following xfstests test case reproduces this bug:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
here=`pwd`
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
cd /
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# remove previous $seqres.full before test
rm -f $seqres.full
# real QA test starts here
_supported_fs btrfs
_supported_os Linux
_require_scratch
rm -f $seqres.full
_scratch_mkfs
_scratch_mount
_run_btrfs_util_prog quota enable $SCRATCH_MNT
# The qgroup '1/10' does not exist and should be silently ignored
_run_btrfs_util_prog subvolume snapshot -i 1/10 $SCRATCH_MNT $SCRATCH_MNT/snap1
_scratch_unmount
echo "Silence is golden"
status=0
exit
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As one user in mail list report reproducible balance ENOSPC error, it's
better to add more debug info for enospc_debug mount option.
Reported-by: Marc Haber <mh+linux-btrfs@zugschlus.de>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Dan Carpenter's static checker has found this error, it's introduced by
commit 64c043de46
("Btrfs: fix up read_tree_block to return proper error")
It's really supposed to 'break' the loop on error like others.
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.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>
- We call inode_size_ok() only if FL_KEEP_SIZE isn't specified.
- As an optimisation we can skip the call if (off + len)
isn't greater than the current size of the file. This operation
is called under the lock so the less work we do, the better.
- If we call inode_size_ok() pass to it the correct value rather
than a more conservative estimation.
Signed-off-by: Davide Italiano <dccitaliano@gmail.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
transaction_kthread() is calling try_to_freeze(), but that's just an
expeinsive no-op given the fact that the thread is not marked freezable.
After removing this, disk-io.c is now independent on freezer API.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
cleaner_kthread() is not marked freezable, and therefore calling
try_to_freeze() in its context is a pointless no-op.
In addition to that, as has been clearly demonstrated by 80ad623edd
("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"), it's perfectly
valid / legal for cleaner_kthread() to stay scheduled out in an arbitrary
place during suspend (in that particular example that was waiting for
reading of extent pages), so there is no need to leave any traces of
freezer in this kthread.
Fixes: 80ad623edd ("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()")
Fixes: 6962491321 ("btrfs: clear PF_NOFREEZE in cleaner_kthread()")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
csum_dirty_buffer was issuing a warning in case the extent buffer
did not look alright, but was still returning success.
Let's return error in this case, and also add an additional sanity
check on the extent buffer header.
The caller up the chain may BUG_ON on this, for example flush_epd_write_bio will,
but it is better than to have a silent metadata corruption on disk.
Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit c40a3d38af (Btrfs: Compute and look up csums based on
sectorsized blocks) changes around how we walk the bios while looking up
crcs. There's an inner loop that is jumping to the next bvec based on
sectors and before it derefs the next bvec, it needs to make sure we're
still in the bio.
In this case, the outer loop would have decided to stop moving forward
too, and the bvec deref is never actually used for anything. But
CONFIG_DEBUG_PAGEALLOC catches it because we're outside our bio.
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Dont print warning for ENOSPC error unless ENOSPC_DEBUG is enabled. Use
btrfs_debug if it is enabled.
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
[ preserve the WARN_ON ]
Signed-off-by: David Sterba <dsterba@suse.com>
It's basically harmless if "ref_level" isn't initialized since it's only
used for an error message, but it causes a static checker warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.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>
So that it indicates what it does.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's better to show a warning message for the exceptional case
that one of objectid (in most case, inode number) reaches its
highest value. For example, if inode cache is off and this event
happens, we can't create any file even if there are not so many files.
This message ease detecting such problem.
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is more readable.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When logging that an inode exists, for example as part of a directory
fsync operation, we were collecting any ordered extents for the inode but
we ended up doing nothing with them except tagging them as processed, by
setting the flag BTRFS_ORDERED_LOGGED on them, which prevented a
subsequent fsync of that inode (using the LOG_INODE_ALL mode) from
collecting and processing them. This created a time window where a second
fsync against the inode, using the fast path, ended up not logging the
checksums for the new extents but it logged the extents since they were
part of the list of modified extents. This happened because the ordered
extents were not collected and checksums were not yet added to the csum
tree - the ordered extents have not gone through btrfs_finish_ordered_io()
yet (which is where we add them to the csum tree by calling
inode.c:add_pending_csums()).
So fix this by not collecting an inode's ordered extents if we are logging
it with the LOG_INODE_EXISTS mode.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
If we're about to do a fast fsync for an inode and btrfs_inode_in_log()
returns false, it's possible that we had an ordered extent in progress
(btrfs_finish_ordered_io() not run yet) when we noticed that the inode's
last_trans field was not greater than the id of the last committed
transaction, but shortly after, before we checked if there were any
ongoing ordered extents, the ordered extent had just completed and
removed itself from the inode's ordered tree, in which case we end up not
logging the inode, losing some data if a power failure or crash happens
after the fsync handler returns and before the transaction is committed.
Fix this by checking first if there are any ongoing ordered extents
before comparing the inode's last_trans with the id of the last committed
transaction - when it completes, an ordered extent always updates the
inode's last_trans before it removes itself from the inode's ordered
tree (at btrfs_finish_ordered_io()).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
In the listxattrs handler, we were not listing all the xattrs that are
packed in the same btree item, which happens when multiple xattrs have
a name that when crc32c hashed produce the same checksum value.
Fix this by processing them all.
The following test case for xfstests reproduces the issue:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
cd /
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/attr
# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_scratch
_require_attrs
rm -f $seqres.full
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount
# Create our test file with a few xattrs. The first 3 xattrs have a name
# that when given as input to a crc32c function result in the same checksum.
# This made btrfs list only one of the xattrs through listxattrs system call
# (because it packs xattrs with the same name checksum into the same btree
# item).
touch $SCRATCH_MNT/testfile
$SETFATTR_PROG -n user.foobar -v 123 $SCRATCH_MNT/testfile
$SETFATTR_PROG -n user.WvG1c1Td -v qwerty $SCRATCH_MNT/testfile
$SETFATTR_PROG -n user.J3__T_Km3dVsW_ -v hello $SCRATCH_MNT/testfile
$SETFATTR_PROG -n user.something -v pizza $SCRATCH_MNT/testfile
$SETFATTR_PROG -n user.ping -v pong $SCRATCH_MNT/testfile
# Now call getfattr with --dump, which calls the listxattrs system call.
# It should list all the xattrs we have set before.
$GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/testfile | _filter_scratch
status=0
exit
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
When using the same file as the source and destination for a dedup
(extent_same ioctl) operation we were allowing it to dedup to a
destination offset beyond the file's size, which doesn't make sense and
it's not allowed for the case where the source and destination files are
not the same file. This made de deduplication operation successful only
when the source range corresponded to a hole, a prealloc extent or an
extent with all bytes having a value of 0x00. This was also leaving a
file hole (between i_size and destination offset) without the
corresponding file extent items, which can be reproduced with the
following steps for example:
$ mkfs.btrfs -f /dev/sdi
$ mount /dev/sdi /mnt/sdi
$ xfs_io -f -c "pwrite -S 0xab 304457 404990" /mnt/sdi/foobar
wrote 404990/404990 bytes at offset 304457
395 KiB, 99 ops; 0.0000 sec (31.150 MiB/sec and 7984.5149 ops/sec)
$ /git/hub/duperemove/btrfs-extent-same 24576 /mnt/sdi/foobar 28672 /mnt/sdi/foobar 929792
Deduping 2 total files
(28672, 24576): /mnt/sdi/foobar
(929792, 24576): /mnt/sdi/foobar
1 files asked to be deduped
i: 0, status: 0, bytes_deduped: 24576
24576 total bytes deduped in this operation
$ umount /mnt/sdi
$ btrfsck /dev/sdi
Checking filesystem on /dev/sdi
UUID: 98c528aa-0833-427d-9403-b98032ffbf9d
checking extents
checking free space cache
checking fs roots
root 5 inode 257 errors 100, file extent discount
Found file extent holes:
start: 712704, len: 217088
found 540673 bytes used err is 1
total csum bytes: 400
total tree bytes: 131072
total fs tree bytes: 32768
total extent tree bytes: 16384
btree space waste bytes: 123675
file data blocks allocated: 671744
referenced 671744
btrfs-progs v4.2.3
So fix this by not allowing the destination to go beyond the file's size,
just as we do for the same where the source and destination files are not
the same.
A test for xfstests follows.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
We have two cases where we end up deleting a file at log replay time
when we should not. For this to happen the file must have been renamed
and a directory inode must have been fsynced/logged.
Two examples that exercise these two cases are listed below.
Case 1)
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir -p /mnt/a/b
$ mkdir /mnt/c
$ touch /mnt/a/b/foo
$ sync
$ mv /mnt/a/b/foo /mnt/c/
# Create file bar just to make sure the fsync on directory a/ does
# something and it's not a no-op.
$ touch /mnt/a/bar
$ xfs_io -c "fsync" /mnt/a
< power fail / crash >
The next time the filesystem is mounted, the log replay procedure
deletes file foo.
Case 2)
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/a
$ mkdir /mnt/b
$ mkdir /mnt/c
$ touch /mnt/a/foo
$ ln /mnt/a/foo /mnt/b/foo_link
$ touch /mnt/b/bar
$ sync
$ unlink /mnt/b/foo_link
$ mv /mnt/b/bar /mnt/c/
$ xfs_io -c "fsync" /mnt/a/foo
< power fail / crash >
The next time the filesystem is mounted, the log replay procedure
deletes file bar.
The reason why the files are deleted is because when we log inodes
other then the fsync target inode, we ignore their last_unlink_trans
value and leave the log without enough information to later replay the
rename operations. So we need to look at the last_unlink_trans values
and fallback to a transaction commit if they are greater than the
id of the last committed transaction.
So fix this by looking at the last_unlink_trans values and fallback to
transaction commits when needed. Also, when logging other inodes (for
case 1 we logged descendants of the fsync target inode while for case 2
we logged ascendants) we need to care about concurrent tasks updating
the last_unlink_trans of inodes we are logging (which was already an
existing problem in check_parent_dirs_for_sync()). Since we can not
acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes
deadlocks with other concurrent operations that acquire the i_mutex of
2 inodes (other fsyncs or renames for example), we need to serialize on
the log_mutex of the inode we are logging. A task setting a new value for
an inode's last_unlink_trans must acquire the inode's log_mutex and it
must do this update before doing the actual unlink operation (which is
already the case except when deleting a snapshot). Conversely the task
logging the inode must first log the inode and then check the inode's
last_unlink_trans value while holding its log_mutex, as if its value is
not greater then the id of the last committed transaction it means it
logged a safe state of the inode's items, while if its value is not
smaller then the id of the last committed transaction it means the inode
state it has logged might not be safe (the concurrent task might have
just updated last_unlink_trans but hasn't done yet the unlink operation)
and therefore a transaction commit must be done.
Test cases for xfstests follow in separate patches.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
If we delete a snapshot, fsync its parent directory and crash/power fail
before the next transaction commit, on the next mount when we attempt to
replay the log tree of the root containing the parent directory we will
fail and prevent the filesystem from mounting, which is solvable by wiping
out the log trees with the btrfs-zero-log tool but very inconvenient as
we will lose any data and metadata fsynced before the parent directory
was fsynced.
For example:
$ 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
$ xfs_io -c "fsync" /mnt/testdir
< crash / power failure and reboot >
$ mount /dev/sdc /mnt
mount: mount(2) failed: No such file or directory
And in dmesg/syslog we get the following message and trace:
[192066.361162] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257
[192066.363010] ------------[ cut here ]------------
[192066.365268] WARNING: CPU: 4 PID: 5130 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x17a/0x354 [btrfs]()
[192066.367250] BTRFS: Transaction aborted (error -2)
[192066.368401] Modules linked in: btrfs dm_flakey dm_mod ppdev sha256_generic xor raid6_pq hmac drbg ansi_cprng aesni_intel acpi_cpufreq tpm_tis aes_x86_64 tpm ablk_helper evdev cryptd sg parport_pc i2c_piix4 psmouse lrw parport i2c_core pcspkr gf128mul processor serio_raw glue_helper button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs]
[192066.377154] CPU: 4 PID: 5130 Comm: mount Tainted: G W 4.4.0-rc6-btrfs-next-20+ #1
[192066.378875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[192066.380889] 0000000000000000 ffff880143923670 ffffffff81257570 ffff8801439236b8
[192066.382561] ffff8801439236a8 ffffffff8104ec07 ffffffffa039dc2c 00000000fffffffe
[192066.384191] ffff8801ed31d000 ffff8801b9fc9c88 ffff8801086875e0 ffff880143923710
[192066.385827] Call Trace:
[192066.386373] [<ffffffff81257570>] dump_stack+0x4e/0x79
[192066.387387] [<ffffffff8104ec07>] warn_slowpath_common+0x99/0xb2
[192066.388429] [<ffffffffa039dc2c>] ? __btrfs_unlink_inode+0x17a/0x354 [btrfs]
[192066.389236] [<ffffffff8104ec68>] warn_slowpath_fmt+0x48/0x50
[192066.389884] [<ffffffffa039dc2c>] __btrfs_unlink_inode+0x17a/0x354 [btrfs]
[192066.390621] [<ffffffff81184b55>] ? iput+0xb0/0x266
[192066.391200] [<ffffffffa039ea25>] btrfs_unlink_inode+0x1c/0x3d [btrfs]
[192066.391930] [<ffffffffa03ca623>] check_item_in_log+0x1fe/0x29b [btrfs]
[192066.392715] [<ffffffffa03ca827>] replay_dir_deletes+0x167/0x1cf [btrfs]
[192066.393510] [<ffffffffa03cccc7>] replay_one_buffer+0x417/0x570 [btrfs]
[192066.394241] [<ffffffffa03ca164>] walk_up_log_tree+0x10e/0x1dc [btrfs]
[192066.394958] [<ffffffffa03cac72>] walk_log_tree+0xa5/0x190 [btrfs]
[192066.395628] [<ffffffffa03ce8b8>] btrfs_recover_log_trees+0x239/0x32c [btrfs]
[192066.396790] [<ffffffffa03cc8b0>] ? replay_one_extent+0x50a/0x50a [btrfs]
[192066.397891] [<ffffffffa0394041>] open_ctree+0x1d8b/0x2167 [btrfs]
[192066.398897] [<ffffffffa03706e1>] btrfs_mount+0x5ef/0x729 [btrfs]
[192066.399823] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf
[192066.400739] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3
[192066.401700] [<ffffffff811714b9>] mount_fs+0x67/0x131
[192066.402482] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde
[192066.403930] [<ffffffffa03702bd>] btrfs_mount+0x1cb/0x729 [btrfs]
[192066.404831] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf
[192066.405726] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3
[192066.406621] [<ffffffff811714b9>] mount_fs+0x67/0x131
[192066.407401] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde
[192066.408247] [<ffffffff8118ae36>] do_mount+0x893/0x9d2
[192066.409047] [<ffffffff8113009b>] ? strndup_user+0x3f/0x8c
[192066.409842] [<ffffffff8118b187>] SyS_mount+0x75/0xa1
[192066.410621] [<ffffffff8147e517>] entry_SYSCALL_64_fastpath+0x12/0x6b
[192066.411572] ---[ end trace 2de42126c1e0a0f0 ]---
[192066.412344] BTRFS: error (device dm-0) in __btrfs_unlink_inode:3986: errno=-2 No such entry
[192066.413748] BTRFS: error (device dm-0) in btrfs_replay_log:2464: errno=-2 No such entry (Failed to recover log tree)
[192066.415458] BTRFS error (device dm-0): cleaner transaction attach returned -30
[192066.444613] BTRFS: open_ctree failed
This happens because when we are replaying the log and processing the
directory entry pointing to the snapshot in the subvolume tree, we treat
its btrfs_dir_item item as having a location with a key type matching
BTRFS_INODE_ITEM_KEY, which is wrong because the type matches
BTRFS_ROOT_ITEM_KEY and therefore must be processed differently, as the
object id refers to a root number and not to an inode in the root
containing the parent directory.
So fix this by triggering a transaction commit if an fsync against the
parent directory is requested after deleting a snapshot. This is the
simplest approach for a rare use case. Some alternative that avoids the
transaction commit would require more code to explicitly delete the
snapshot at log replay time (factoring out common code from ioctl.c:
btrfs_ioctl_snap_destroy()), special care at fsync time to remove the
log tree of the snapshot's root from the log root of the root of tree
roots, amongst other steps.
A test case for xfstests that triggers the issue follows.
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
_cleanup_flakey
cd /
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/dmflakey
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_dm_target flakey
_require_metadata_journaling $SCRATCH_DEV
rm -f $seqres.full
_scratch_mkfs >>$seqres.full 2>&1
_init_flakey
_mount_flakey
# Create a snapshot at the root of our filesystem (mount point path), delete it,
# fsync the mount point path, crash and mount to replay the log. This should
# succeed and after the filesystem is mounted the snapshot should not be visible
# anymore.
_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap1
_run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT
_flakey_drop_and_remount
[ -e $SCRATCH_MNT/snap1 ] && \
echo "Snapshot snap1 still exists after log replay"
# Similar scenario as above, but this time the snapshot is created inside a
# directory and not directly under the root (mount point path).
mkdir $SCRATCH_MNT/testdir
_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/testdir/snap2
_run_btrfs_util_prog subvolume delete $SCRATCH_MNT/testdir/snap2
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir
_flakey_drop_and_remount
[ -e $SCRATCH_MNT/testdir/snap2 ] && \
echo "Snapshot snap2 still exists after log replay"
_unmount_flakey
echo "Silence is golden"
status=0
exit
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Pull vfs fixes from Al Viro.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
do_last(): ELOOP failure exit should be done after leaving RCU mode
should_follow_link(): validate ->d_seq after having decided to follow
namei: ->d_inode of a pinned dentry is stable only for positives
do_last(): don't let a bogus return value from ->open() et.al. to confuse us
fs: return -EOPNOTSUPP if clone is not supported
hpfs: don't truncate the file when delete fails
... otherwise d_is_symlink() above might have nothing to do with
the inode value we've got.
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
both do_last() and walk_component() risk picking a NULL inode out
of dentry about to become positive, *then* checking its flags and
seeing that it's not negative anymore and using (already stale by
then) value they'd fetched earlier. Usually ends up oopsing soon
after that...
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... into returning a positive to path_openat(), which would interpret that
as "symlink had been encountered" and proceed to corrupt memory, etc.
It can only happen due to a bug in some ->open() instance or in some LSM
hook, etc., so we report any such event *and* make sure it doesn't trick
us into further unpleasantness.
Cc: stable@vger.kernel.org # v3.6+, at least
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-EBADF is a rather confusing error if an operations is not supported,
and nfsd gets rather upset about it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The delete opration can allocate additional space on the HPFS filesystem
due to btree split. The HPFS driver checks in advance if there is
available space, so that it won't corrupt the btree if we run out of space
during splitting.
If there is not enough available space, the HPFS driver attempted to
truncate the file, but this results in a deadlock since the commit
7dd29d8d86 ("HPFS: Introduce a global mutex
and lock it on every callback from VFS").
This patch removes the code that tries to truncate the file and -ENOSPC is
returned instead. If the user hits -ENOSPC on delete, he should try to
delete other files (that are stored in a leaf btree node), so that the
delete operation will make some space for deleting the file stored in
non-leaf btree node.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Merge fixes from Andrew Morton:
"10 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
dax: move writeback calls into the filesystems
dax: give DAX clearing code correct bdev
ext4: online defrag not supported with DAX
ext2, ext4: only set S_DAX for regular inodes
block: disable block device DAX by default
ocfs2: unlock inode if deleting inode from orphan fails
mm: ASLR: use get_random_long()
drivers: char: random: add get_random_long()
mm: numa: quickly fail allocations for NUMA balancing on full nodes
mm: thp: fix SMP race condition between THP page fault and MADV_DONTNEED
As it is currently written ext4_dax_mkwrite() assumes that the call into
__dax_mkwrite() will not have to do a block allocation so it doesn't create
a journal entry. For a read that creates a zero page to cover a hole
followed by a write that actually allocates storage this is incorrect. The
ext4_dax_mkwrite() -> __dax_mkwrite() -> __dax_fault() path calls
get_blocks() to allocate storage.
Fix this by having the ->page_mkwrite fault handler call ext4_dax_fault()
as this function already has all the logic needed to allocate a journal
entry and call __dax_fault().
Also update the ext2 fault handlers in this same way to remove duplicate
code and keep the logic between ext2 and ext4 the same.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Previously calls to dax_writeback_mapping_range() for all DAX filesystems
(ext2, ext4 & xfs) were centralized in filemap_write_and_wait_range().
dax_writeback_mapping_range() needs a struct block_device, and it used
to get that from inode->i_sb->s_bdev. This is correct for normal inodes
mounted on ext2, ext4 and XFS filesystems, but is incorrect for DAX raw
block devices and for XFS real-time files.
Instead, call dax_writeback_mapping_range() directly from the filesystem
->writepages function so that it can supply us with a valid block
device. This also fixes DAX code to properly flush caches in response
to sync(2).
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dax_clear_blocks() needs a valid struct block_device and previously it
was using inode->i_sb->s_bdev in all cases. This is correct for normal
inodes on mounted ext2, ext4 and XFS filesystems, but is incorrect for
DAX raw block devices and for XFS real-time devices.
Instead, rename dax_clear_blocks() to dax_clear_sectors(), and change
its arguments to take a bdev and a sector instead of an inode and a
block. This better reflects what the function does, and it allows the
filesystem and raw block device code to pass in an appropriate struct
block_device.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Online defrag operations for ext4 are hard coded to use the page cache.
See ext4_ioctl() -> ext4_move_extents() -> move_extent_per_page()
When combined with DAX I/O, which circumvents the page cache, this can
result in data corruption. This was observed with xfstests ext4/307 and
ext4/308.
Fix this by only allowing online defrag for non-DAX files.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When S_DAX is set on an inode we assume that if there are pages attached
to the mapping (mapping->nrpages != 0), those pages are clean zero pages
that were used to service reads from holes. Any dirty data associated
with the inode should be in the form of DAX exceptional entries
(mapping->nrexceptional) that is written back via
dax_writeback_mapping_range().
With the current code, though, this isn't always true. For example,
ext2 and ext4 directory inodes can have S_DAX set, but have their dirty
data stored as dirty page cache entries. For these types of inodes,
having S_DAX set doesn't really make sense since their I/O doesn't
actually happen through the DAX code path.
Instead, only allow S_DAX to be set for regular inodes for ext2 and
ext4. This allows us to have strict DAX vs non-DAX paths in the
writeback code.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recent *sync enabling discovered that we are inserting into the
block_device pagecache counter to the expectations of the dirty data
tracking for dax mappings. This can lead to data corruption.
We want to support DAX for block devices eventually, but it requires
wider changes to properly manage the pagecache.
dump_stack+0x85/0xc2
dax_writeback_mapping_range+0x60/0xe0
blkdev_writepages+0x3f/0x50
do_writepages+0x21/0x30
__filemap_fdatawrite_range+0xc6/0x100
filemap_write_and_wait+0x4a/0xa0
set_blocksize+0x70/0xd0
sb_set_blocksize+0x1d/0x50
ext4_fill_super+0x75b/0x3360
mount_bdev+0x180/0x1b0
ext4_mount+0x15/0x20
mount_fs+0x38/0x170
Mark the support broken so its disabled by default, but otherwise still
available for testing.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When doing append direct io cleanup, if deleting inode fails, it goes
out without unlocking inode, which will cause the inode deadlock.
This issue was introduced by commit cf1776a9e8 ("ocfs2: fix a tiny
race when truncate dio orohaned entry").
Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org> [4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace calls to get_random_int() followed by a cast to (unsigned long)
with calls to get_random_long(). Also address shifting bug which, in
case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits.
Signed-off-by: Daniel Cashman <dcashman@android.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nick Kralevich <nnk@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
