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epyc7002
9479 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Filipe Manana
|
54f290efac |
btrfs: fix race between marking inode needs to be logged and log syncing
commit bc0939fcfab0d7efb2ed12896b1af3d819954a14 upstream.
We have a race between marking that an inode needs to be logged, either
at btrfs_set_inode_last_trans() or at btrfs_page_mkwrite(), and between
btrfs_sync_log(). The following steps describe how the race happens.
1) We are at transaction N;
2) Inode I was previously fsynced in the current transaction so it has:
inode->logged_trans set to N;
3) The inode's root currently has:
root->log_transid set to 1
root->last_log_commit set to 0
Which means only one log transaction was committed to far, log
transaction 0. When a log tree is created we set ->log_transid and
->last_log_commit of its parent root to 0 (at btrfs_add_log_tree());
4) One more range of pages is dirtied in inode I;
5) Some task A starts an fsync against some other inode J (same root), and
so it joins log transaction 1.
Before task A calls btrfs_sync_log()...
6) Task B starts an fsync against inode I, which currently has the full
sync flag set, so it starts delalloc and waits for the ordered extent
to complete before calling btrfs_inode_in_log() at btrfs_sync_file();
7) During ordered extent completion we have btrfs_update_inode() called
against inode I, which in turn calls btrfs_set_inode_last_trans(),
which does the following:
spin_lock(&inode->lock);
inode->last_trans = trans->transaction->transid;
inode->last_sub_trans = inode->root->log_transid;
inode->last_log_commit = inode->root->last_log_commit;
spin_unlock(&inode->lock);
So ->last_trans is set to N and ->last_sub_trans set to 1.
But before setting ->last_log_commit...
8) Task A is at btrfs_sync_log():
- it increments root->log_transid to 2
- starts writeback for all log tree extent buffers
- waits for the writeback to complete
- writes the super blocks
- updates root->last_log_commit to 1
It's a lot of slow steps between updating root->log_transid and
root->last_log_commit;
9) The task doing the ordered extent completion, currently at
btrfs_set_inode_last_trans(), then finally runs:
inode->last_log_commit = inode->root->last_log_commit;
spin_unlock(&inode->lock);
Which results in inode->last_log_commit being set to 1.
The ordered extent completes;
10) Task B is resumed, and it calls btrfs_inode_in_log() which returns
true because we have all the following conditions met:
inode->logged_trans == N which matches fs_info->generation &&
inode->last_subtrans (1) <= inode->last_log_commit (1) &&
inode->last_subtrans (1) <= root->last_log_commit (1) &&
list inode->extent_tree.modified_extents is empty
And as a consequence we return without logging the inode, so the
existing logged version of the inode does not point to the extent
that was written after the previous fsync.
It should be impossible in practice for one task be able to do so much
progress in btrfs_sync_log() while another task is at
btrfs_set_inode_last_trans() right after it reads root->log_transid and
before it reads root->last_log_commit. Even if kernel preemption is enabled
we know the task at btrfs_set_inode_last_trans() can not be preempted
because it is holding the inode's spinlock.
However there is another place where we do the same without holding the
spinlock, which is in the memory mapped write path at:
vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
{
(...)
BTRFS_I(inode)->last_trans = fs_info->generation;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
(...)
So with preemption happening after setting ->last_sub_trans and before
setting ->last_log_commit, it is less of a stretch to have another task
do enough progress at btrfs_sync_log() such that the task doing the memory
mapped write ends up with ->last_sub_trans and ->last_log_commit set to
the same value. It is still a big stretch to get there, as the task doing
btrfs_sync_log() has to start writeback, wait for its completion and write
the super blocks.
So fix this in two different ways:
1) For btrfs_set_inode_last_trans(), simply set ->last_log_commit to the
value of ->last_sub_trans minus 1;
2) For btrfs_page_mkwrite() only set the inode's ->last_sub_trans, just
like we do for buffered and direct writes at btrfs_file_write_iter(),
which is all we need to make sure multiple writes and fsyncs to an
inode in the same transaction never result in an fsync missing that
the inode changed and needs to be logged. Turn this into a helper
function and use it both at btrfs_page_mkwrite() and at
btrfs_file_write_iter() - this also fixes the problem that at
btrfs_page_mkwrite() we were setting those fields without the
protection of the inode's spinlock.
This is an extremely unlikely race to happen in practice.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Qu Wenruo
|
aa825dbd39 |
Revert "btrfs: compression: don't try to compress if we don't have enough pages"
commit 4e9655763b82a91e4c341835bb504a2b1590f984 upstream.
This reverts commit f2165627319ffd33a6217275e5690b1ab5c45763.
[BUG]
It's no longer possible to create compressed inline extent after commit
f2165627319f ("btrfs: compression: don't try to compress if we don't
have enough pages").
[CAUSE]
For compression code, there are several possible reasons we have a range
that needs to be compressed while it's no more than one page.
- Compressed inline write
The data is always smaller than one sector and the test lacks the
condition to properly recognize a non-inline extent.
- Compressed subpage write
For the incoming subpage compressed write support, we require page
alignment of the delalloc range.
And for 64K page size, we can compress just one page into smaller
sectors.
For those reasons, the requirement for the data to be more than one page
is not correct, and is already causing regression for compressed inline
data writeback. The idea of skipping one page to avoid wasting CPU time
could be revisited in the future.
[FIX]
Fix it by reverting the offending commit.
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/afa2742.c084f5d6.17b6b08dffc@tnonline.net
Fixes: f2165627319f ("btrfs: compression: don't try to compress if we don't have enough pages")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@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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NeilBrown
|
2e577c6821 |
btrfs: prevent rename2 from exchanging a subvol with a directory from different parents
[ Upstream commit 3f79f6f6247c83f448c8026c3ee16d4636ef8d4f ]
Cross-rename lacks a check when that would prevent exchanging a
directory and subvolume from different parent subvolume. This causes
data inconsistencies and is caught before commit by tree-checker,
turning the filesystem to read-only.
Calling the renameat2 with RENAME_EXCHANGE flags like
renameat2(AT_FDCWD, namesrc, AT_FDCWD, namedest, (1 << 1))
on two paths:
namesrc = dir1/subvol1/dir2
namedest = subvol2/subvol3
will cause key order problem with following write time tree-checker
report:
[1194842.307890] BTRFS critical (device loop1): corrupt leaf: root=5 block=27574272 slot=10 ino=258, invalid previous key objectid, have 257 expect 258
[1194842.322221] BTRFS info (device loop1): leaf 27574272 gen 8 total ptrs 11 free space 15444 owner 5
[1194842.331562] BTRFS info (device loop1): refs 2 lock_owner 0 current 26561
[1194842.338772] item 0 key (256 1 0) itemoff 16123 itemsize 160
[1194842.338793] inode generation 3 size 16 mode 40755
[1194842.338801] item 1 key (256 12 256) itemoff 16111 itemsize 12
[1194842.338809] item 2 key (256 84 2248503653) itemoff 16077 itemsize 34
[1194842.338817] dir oid 258 type 2
[1194842.338823] item 3 key (256 84 2363071922) itemoff 16043 itemsize 34
[1194842.338830] dir oid 257 type 2
[1194842.338836] item 4 key (256 96 2) itemoff 16009 itemsize 34
[1194842.338843] item 5 key (256 96 3) itemoff 15975 itemsize 34
[1194842.338852] item 6 key (257 1 0) itemoff 15815 itemsize 160
[1194842.338863] inode generation 6 size 8 mode 40755
[1194842.338869] item 7 key (257 12 256) itemoff 15801 itemsize 14
[1194842.338876] item 8 key (257 84 2505409169) itemoff 15767 itemsize 34
[1194842.338883] dir oid 256 type 2
[1194842.338888] item 9 key (257 96 2) itemoff 15733 itemsize 34
[1194842.338895] item 10 key (258 12 256) itemoff 15719 itemsize 14
[1194842.339163] BTRFS error (device loop1): block=27574272 write time tree block corruption detected
[1194842.339245] ------------[ cut here ]------------
[1194842.443422] WARNING: CPU: 6 PID: 26561 at fs/btrfs/disk-io.c:449 csum_one_extent_buffer+0xed/0x100 [btrfs]
[1194842.511863] CPU: 6 PID: 26561 Comm: kworker/u17:2 Not tainted 5.14.0-rc3-git+ #793
[1194842.511870] Hardware name: empty empty/S3993, BIOS PAQEX0-3 02/24/2008
[1194842.511876] Workqueue: btrfs-worker-high btrfs_work_helper [btrfs]
[1194842.511976] RIP: 0010:csum_one_extent_buffer+0xed/0x100 [btrfs]
[1194842.512068] RSP: 0018:ffffa2c284d77da0 EFLAGS: 00010282
[1194842.512074] RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff928867bd9978
[1194842.512078] RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff928867bd9970
[1194842.512081] RBP: ffff92876b958000 R08: 0000000000000001 R09: 00000000000c0003
[1194842.512085] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
[1194842.512088] R13: ffff92875f989f98 R14: 0000000000000000 R15: 0000000000000000
[1194842.512092] FS: 0000000000000000(0000) GS:ffff928867a00000(0000) knlGS:0000000000000000
[1194842.512095] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1194842.512099] CR2: 000055f5384da1f0 CR3: 0000000102fe4000 CR4: 00000000000006e0
[1194842.512103] Call Trace:
[1194842.512128] ? run_one_async_free+0x10/0x10 [btrfs]
[1194842.631729] btree_csum_one_bio+0x1ac/0x1d0 [btrfs]
[1194842.631837] run_one_async_start+0x18/0x30 [btrfs]
[1194842.631938] btrfs_work_helper+0xd5/0x1d0 [btrfs]
[1194842.647482] process_one_work+0x262/0x5e0
[1194842.647520] worker_thread+0x4c/0x320
[1194842.655935] ? process_one_work+0x5e0/0x5e0
[1194842.655946] kthread+0x135/0x160
[1194842.655953] ? set_kthread_struct+0x40/0x40
[1194842.655965] ret_from_fork+0x1f/0x30
[1194842.672465] irq event stamp: 1729
[1194842.672469] hardirqs last enabled at (1735): [<ffffffffbd1104f5>] console_trylock_spinning+0x185/0x1a0
[1194842.672477] hardirqs last disabled at (1740): [<ffffffffbd1104cc>] console_trylock_spinning+0x15c/0x1a0
[1194842.672482] softirqs last enabled at (1666): [<ffffffffbdc002e1>] __do_softirq+0x2e1/0x50a
[1194842.672491] softirqs last disabled at (1651): [<ffffffffbd08aab7>] __irq_exit_rcu+0xa7/0xd0
The corrupted data will not be written, and filesystem can be unmounted
and mounted again (all changes since the last commit will be lost).
Add the missing check for new_ino so that all non-subvolumes must reside
under the same parent subvolume. There's an exception allowing to
exchange two subvolumes from any parents as the directory representing a
subvolume is only a logical link and does not have any other structures
related to the parent subvolume, unlike files, directories etc, that
are always in the inode namespace of the parent subvolume.
Fixes:
|
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Filipe Manana
|
4b5ca02bea |
btrfs: fix lost inode on log replay after mix of fsync, rename and inode eviction
[ Upstream commit ecc64fab7d49c678e70bd4c35fe64d2ab3e3d212 ] When checking if we need to log the new name of a renamed inode, we are checking if the inode and its parent inode have been logged before, and if not we don't log the new name. The check however is buggy, as it directly compares the logged_trans field of the inodes versus the ID of the current transaction. The problem is that logged_trans is a transient field, only stored in memory and never persisted in the inode item, so if an inode was logged before, evicted and reloaded, its logged_trans field is set to a value of 0, meaning the check will return false and the new name of the renamed inode is not logged. If the old parent directory was previously fsynced and we deleted the logged directory entries corresponding to the old name, we end up with a log that when replayed will delete the renamed inode. The following example triggers the problem: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ echo -n "hello world" > /mnt/A/foo $ sync # Add some new file to A and fsync directory A. $ touch /mnt/A/bar $ xfs_io -c "fsync" /mnt/A # Now trigger inode eviction. We are only interested in triggering # eviction for the inode of directory A. $ echo 2 > /proc/sys/vm/drop_caches # Move foo from directory A to directory B. # This deletes the directory entries for foo in A from the log, and # does not add the new name for foo in directory B to the log, because # logged_trans of A is 0, which is less than the current transaction ID. $ mv /mnt/A/foo /mnt/B/foo # Now make an fsync to anything except A, B or any file inside them, # like for example create a file at the root directory and fsync this # new file. This syncs the log that contains all the changes done by # previous rename operation. $ touch /mnt/baz $ xfs_io -c "fsync" /mnt/baz <power fail> # Mount the filesystem and replay the log. $ mount /dev/sdc /mnt # Check the filesystem content. $ ls -1R /mnt /mnt/: A B baz /mnt/A: bar /mnt/B: $ # File foo is gone, it's neither in A/ nor in B/. Fix this by using the inode_logged() helper at btrfs_log_new_name(), which safely checks if an inode was logged before in the current transaction. A test case for fstests will follow soon. 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: Sasha Levin <sashal@kernel.org> |
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Goldwyn Rodrigues
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be9ad66510 |
btrfs: mark compressed range uptodate only if all bio succeed
commit 240246f6b913b0c23733cfd2def1d283f8cc9bbe upstream. In compression write endio sequence, the range which the compressed_bio writes is marked as uptodate if the last bio of the compressed (sub)bios is completed successfully. There could be previous bio which may have failed which is recorded in cb->errors. Set the writeback range as uptodate only if cb->errors is zero, as opposed to checking only the last bio's status. Backporting notes: in all versions up to 4.4 the last argument is always replaced by "!cb->errors". CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Goldwyn Rodrigues <rgoldwyn@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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Desmond Cheong Zhi Xi
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1163bca65a |
btrfs: fix rw device counting in __btrfs_free_extra_devids
commit b2a616676839e2a6b02c8e40be7f886f882ed194 upstream. When removing a writeable device in __btrfs_free_extra_devids, the rw device count should be decremented. This error was caught by Syzbot which reported a warning in close_fs_devices: WARNING: CPU: 1 PID: 9355 at fs/btrfs/volumes.c:1168 close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168 Modules linked in: CPU: 0 PID: 9355 Comm: syz-executor552 Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168 RSP: 0018:ffffc9000333f2f0 EFLAGS: 00010293 RAX: ffffffff8365f5c3 RBX: 0000000000000001 RCX: ffff888029afd4c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88802846f508 R08: ffffffff8365f525 R09: ffffed100337d128 R10: ffffed100337d128 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888019be8868 R14: 1ffff1100337d10d R15: 1ffff1100337d10a FS: 00007f6f53828700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000047c410 CR3: 00000000302a6000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_close_devices+0xc9/0x450 fs/btrfs/volumes.c:1180 open_ctree+0x8e1/0x3968 fs/btrfs/disk-io.c:3693 btrfs_fill_super fs/btrfs/super.c:1382 [inline] btrfs_mount_root+0xac5/0xc60 fs/btrfs/super.c:1749 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1498 fc_mount fs/namespace.c:993 [inline] vfs_kern_mount+0xc9/0x160 fs/namespace.c:1023 btrfs_mount+0x3d3/0xb50 fs/btrfs/super.c:1809 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Because fs_devices->rw_devices was not 0 after closing all devices. Here is the call trace that was observed: btrfs_mount_root(): btrfs_scan_one_device(): device_list_add(); <---------------- device added btrfs_open_devices(): open_fs_devices(): btrfs_open_one_device(); <-------- writable device opened, rw device count ++ btrfs_fill_super(): open_ctree(): btrfs_free_extra_devids(): __btrfs_free_extra_devids(); <--- writable device removed, rw device count not decremented fail_tree_roots: btrfs_close_devices(): close_fs_devices(); <------- rw device count off by 1 As a note, prior to commit |
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AuxXxilium
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5fa3ea047a |
init: add dsm gpl source
Signed-off-by: AuxXxilium <info@auxxxilium.tech> |
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Anand Jain
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755971dc7e |
btrfs: check for missing device in btrfs_trim_fs
commit 16a200f66ede3f9afa2e51d90ade017aaa18d213 upstream. A fstrim on a degraded raid1 can trigger the following null pointer dereference: BTRFS info (device loop0): allowing degraded mounts BTRFS info (device loop0): disk space caching is enabled BTRFS info (device loop0): has skinny extents BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing BTRFS info (device loop0): enabling ssd optimizations BUG: kernel NULL pointer dereference, address: 0000000000000620 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 4574 Comm: fstrim Not tainted 5.13.0-rc7+ #31 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:btrfs_trim_fs+0x199/0x4a0 [btrfs] RSP: 0018:ffff959541797d28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff946f84eca508 RCX: a7a67937adff8608 RDX: ffff946e8122d000 RSI: 0000000000000000 RDI: ffffffffc02fdbf0 RBP: ffff946ea4615000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffff946e8122d960 R12: 0000000000000000 R13: ffff959541797db8 R14: ffff946e8122d000 R15: ffff959541797db8 FS: 00007f55917a5080(0000) GS:ffff946f9bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000620 CR3: 000000002d2c8001 CR4: 00000000000706f0 Call Trace: btrfs_ioctl_fitrim+0x167/0x260 [btrfs] btrfs_ioctl+0x1c00/0x2fe0 [btrfs] ? selinux_file_ioctl+0x140/0x240 ? syscall_trace_enter.constprop.0+0x188/0x240 ? __x64_sys_ioctl+0x83/0xb0 __x64_sys_ioctl+0x83/0xb0 Reproducer: $ mkfs.btrfs -fq -d raid1 -m raid1 /dev/loop0 /dev/loop1 $ mount /dev/loop0 /btrfs $ umount /btrfs $ btrfs dev scan --forget $ mount -o degraded /dev/loop0 /btrfs $ fstrim /btrfs The reason is we call btrfs_trim_free_extents() for the missing device, which uses device->bdev (NULL for missing device) to find if the device supports discard. Fix is to check if the device is missing before calling btrfs_trim_free_extents(). CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Anand Jain <anand.jain@oracle.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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David Sterba
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eefebcda89 |
btrfs: clear log tree recovering status if starting transaction fails
[ Upstream commit 1aeb6b563aea18cd55c73cf666d1d3245a00f08c ] When a log recovery is in progress, lots of operations have to take that into account, so we keep this status per tree during the operation. Long time ago error handling revamp patch |
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Christophe Leroy
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9c0835c69d |
btrfs: disable build on platforms having page size 256K
[ Upstream commit b05fbcc36be1f8597a1febef4892053a0b2f3f60 ] With a config having PAGE_SIZE set to 256K, BTRFS build fails with the following message include/linux/compiler_types.h:326:38: error: call to '__compiletime_assert_791' declared with attribute error: BUILD_BUG_ON failed: (BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0 BTRFS_MAX_COMPRESSED being 128K, BTRFS cannot support platforms with 256K pages at the time being. There are two platforms that can select 256K pages: - hexagon - powerpc Disable BTRFS when 256K page size is selected. Supporting this would require changes to the subpage mode that's currently being developed. Given that 256K is many times larger than page sizes commonly used and for what the algorithms and structures have been tuned, it's out of scope and disabling build is a reasonable option. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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Qu Wenruo
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ad71a9ad74 |
btrfs: don't clear page extent mapped if we're not invalidating the full page
[ Upstream commit bcd77455d590eaa0422a5e84ae852007cfce574a ] [BUG] With current btrfs subpage rw support, the following script can lead to fs hang: $ mkfs.btrfs -f -s 4k $dev $ mount $dev -o nospace_cache $mnt $ fsstress -w -n 100 -p 1 -s 1608140256 -v -d $mnt The fs will hang at btrfs_start_ordered_extent(). [CAUSE] In above test case, btrfs_invalidate() will be called with the following parameters: offset = 0 length = 53248 page dirty = 1 subpage dirty bitmap = 0x2000 Since @offset is 0, btrfs_invalidate() will try to invalidate the full page, and finally call clear_page_extent_mapped() which will detach subpage structure from the page. And since the page no longer has subpage structure, the subpage dirty bitmap will be cleared, preventing the dirty range from being written back, thus no way to wake up the ordered extent. [FIX] Just follow other filesystems, only to invalidate the page if the range covers the full page. There are cases like truncate_setsize() which can call btrfs_invalidatepage() with offset == 0 and length != 0 for the last page of an inode. Although the old code will still try to invalidate the full page, we are still safe to just wait for ordered extent to finish. So it shouldn't cause extra problems. Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64] Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64] Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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David Sterba
|
703b494a68 |
btrfs: sysfs: fix format string for some discard stats
[ Upstream commit 8c5ec995616f1202ab92e195fd75d6f60d86f85c ] The type of discard_bitmap_bytes and discard_extent_bytes is u64 so the format should be %llu, though the actual values would hardly ever overflow to negative values. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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Josef Bacik
|
8d05e30c97 |
btrfs: abort transaction if we fail to update the delayed inode
[ Upstream commit 04587ad9bef6ce9d510325b4ba9852b6129eebdb ] If we fail to update the delayed inode we need to abort the transaction, because we could leave an inode with the improper counts or some other such corruption behind. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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Josef Bacik
|
e0ffb169a3 |
btrfs: fix error handling in __btrfs_update_delayed_inode
[ Upstream commit bb385bedded3ccbd794559600de4a09448810f4a ] If we get an error while looking up the inode item we'll simply bail without cleaning up the delayed node. This results in this style of warning happening on commit: WARNING: CPU: 0 PID: 76403 at fs/btrfs/delayed-inode.c:1365 btrfs_assert_delayed_root_empty+0x5b/0x90 CPU: 0 PID: 76403 Comm: fsstress Tainted: G W 5.13.0-rc1+ #373 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:btrfs_assert_delayed_root_empty+0x5b/0x90 RSP: 0018:ffffb8bb815a7e50 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff95d6d07e1888 RCX: ffff95d6c0fa3000 RDX: 0000000000000002 RSI: 000000000029e91c RDI: ffff95d6c0fc8060 RBP: ffff95d6c0fc8060 R08: 00008d6d701a2c1d R09: 0000000000000000 R10: ffff95d6d1760ea0 R11: 0000000000000001 R12: ffff95d6c15a4d00 R13: ffff95d6c0fa3000 R14: 0000000000000000 R15: ffffb8bb815a7e90 FS: 00007f490e8dbb80(0000) GS:ffff95d73bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6e75555cb0 CR3: 00000001101ce001 CR4: 0000000000370ef0 Call Trace: btrfs_commit_transaction+0x43c/0xb00 ? finish_wait+0x80/0x80 ? vfs_fsync_range+0x90/0x90 iterate_supers+0x8c/0x100 ksys_sync+0x50/0x90 __do_sys_sync+0xa/0x10 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Because the iref isn't dropped and this leaves an elevated node->count, so any release just re-queues it onto the delayed inodes list. Fix this by going to the out label to handle the proper cleanup of the delayed node. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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David Sterba
|
80d05ce58a |
btrfs: clear defrag status of a root if starting transaction fails
commit 6819703f5a365c95488b07066a8744841bf14231 upstream. The defrag loop processes leaves in batches and starting transaction for each. The whole defragmentation on a given root is protected by a bit but in case the transaction fails, the bit is not cleared In case the transaction fails the bit would prevent starting defragmentation again, so make sure it's cleared. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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David Sterba
|
6b00b1717f |
btrfs: compression: don't try to compress if we don't have enough pages
commit f2165627319ffd33a6217275e5690b1ab5c45763 upstream. The early check if we should attempt compression does not take into account the number of input pages. It can happen that there's only one page, eg. a tail page after some ranges of the BTRFS_MAX_UNCOMPRESSED have been processed, or an isolated page that won't be converted to an inline extent. The single page would be compressed but a later check would drop it again because the result size must be at least one block shorter than the input. That can never work with just one page. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Filipe Manana
|
34172f601a |
btrfs: send: fix invalid path for unlink operations after parent orphanization
commit d8ac76cdd1755b21e8c008c28d0b7251c0b14986 upstream.
During an incremental send operation, when processing the new references
for the current inode, we might send an unlink operation for another inode
that has a conflicting path and has more than one hard link. However this
path was computed and cached before we processed previous new references
for the current inode. We may have orphanized a directory of that path
while processing a previous new reference, in which case the path will
be invalid and cause the receiver process to fail.
The following reproducer triggers the problem and explains how/why it
happens in its comments:
$ cat test-send-unlink.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
mkfs.btrfs -f $DEV >/dev/null
mount $DEV $MNT
# Create our test files and directory. Inode 259 (file3) has two hard
# links.
touch $MNT/file1
touch $MNT/file2
touch $MNT/file3
mkdir $MNT/A
ln $MNT/file3 $MNT/A/hard_link
# Filesystem looks like:
#
# . (ino 256)
# |----- file1 (ino 257)
# |----- file2 (ino 258)
# |----- file3 (ino 259)
# |----- A/ (ino 260)
# |---- hard_link (ino 259)
#
# Now create the base snapshot, which is going to be the parent snapshot
# for a later incremental send.
btrfs subvolume snapshot -r $MNT $MNT/snap1
btrfs send -f /tmp/snap1.send $MNT/snap1
# Move inode 257 into directory inode 260. This results in computing the
# path for inode 260 as "/A" and caching it.
mv $MNT/file1 $MNT/A/file1
# Move inode 258 (file2) into directory inode 260, with a name of
# "hard_link", moving first inode 259 away since it currently has that
# location and name.
mv $MNT/A/hard_link $MNT/tmp
mv $MNT/file2 $MNT/A/hard_link
# Now rename inode 260 to something else (B for example) and then create
# a hard link for inode 258 that has the old name and location of inode
# 260 ("/A").
mv $MNT/A $MNT/B
ln $MNT/B/hard_link $MNT/A
# Filesystem now looks like:
#
# . (ino 256)
# |----- tmp (ino 259)
# |----- file3 (ino 259)
# |----- B/ (ino 260)
# | |---- file1 (ino 257)
# | |---- hard_link (ino 258)
# |
# |----- A (ino 258)
# Create another snapshot of our subvolume and use it for an incremental
# send.
btrfs subvolume snapshot -r $MNT $MNT/snap2
btrfs send -f /tmp/snap2.send -p $MNT/snap1 $MNT/snap2
# Now unmount the filesystem, create a new one, mount it and try to
# apply both send streams to recreate both snapshots.
umount $DEV
mkfs.btrfs -f $DEV >/dev/null
mount $DEV $MNT
# First add the first snapshot to the new filesystem by applying the
# first send stream.
btrfs receive -f /tmp/snap1.send $MNT
# The incremental receive operation below used to fail with the
# following error:
#
# ERROR: unlink A/hard_link failed: No such file or directory
#
# This is because when send is processing inode 257, it generates the
# path for inode 260 as "/A", since that inode is its parent in the send
# snapshot, and caches that path.
#
# Later when processing inode 258, it first processes its new reference
# that has the path of "/A", which results in orphanizing inode 260
# because there is a a path collision. This results in issuing a rename
# operation from "/A" to "/o260-6-0".
#
# Finally when processing the new reference "B/hard_link" for inode 258,
# it notices that it collides with inode 259 (not yet processed, because
# it has a higher inode number), since that inode has the name
# "hard_link" under the directory inode 260. It also checks that inode
# 259 has two hardlinks, so it decides to issue a unlink operation for
# the name "hard_link" for inode 259. However the path passed to the
# unlink operation is "/A/hard_link", which is incorrect since currently
# "/A" does not exists, due to the orphanization of inode 260 mentioned
# before. The path is incorrect because it was computed and cached
# before the orphanization. This results in the receiver to fail with
# the above error.
btrfs receive -f /tmp/snap2.send $MNT
umount $MNT
When running the test, it fails like this:
$ ./test-send-unlink.sh
Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap1'
At subvol /mnt/sdi/snap1
Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap2'
At subvol /mnt/sdi/snap2
At subvol snap1
At snapshot snap2
ERROR: unlink A/hard_link failed: No such file or directory
Fix this by recomputing a path before issuing an unlink operation when
processing the new references for the current inode if we previously
have orphanized a directory.
A test case for fstests will follow 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>
|
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Nikolay Borisov
|
31fe243a63 |
btrfs: promote debugging asserts to full-fledged checks in validate_super
commit aefd7f7065567a4666f42c0fc8cdb379d2e036bf upstream. Syzbot managed to trigger this assert while performing its fuzzing. Turns out it's better to have those asserts turned into full-fledged checks so that in case buggy btrfs images are mounted the users gets an error and mounting is stopped. Alternatively with CONFIG_BTRFS_ASSERT disabled such image would have been erroneously allowed to be mounted. Reported-by: syzbot+a6bf271c02e4fe66b4e4@syzkaller.appspotmail.com CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add uuids to the messages ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Ritesh Harjani
|
ca69dc891b |
btrfs: return value from btrfs_mark_extent_written() in case of error
commit e7b2ec3d3d4ebeb4cff7ae45cf430182fa6a49fb upstream. We always return 0 even in case of an error in btrfs_mark_extent_written(). Fix it to return proper error value in case of a failure. All callers handle it. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.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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Anand Jain
|
fe910d20e2 |
btrfs: fix unmountable seed device after fstrim
commit 5e753a817b2d5991dfe8a801b7b1e8e79a1c5a20 upstream.
The following test case reproduces an issue of wrongly freeing in-use
blocks on the readonly seed device when fstrim is called on the rw sprout
device. As shown below.
Create a seed device and add a sprout device to it:
$ mkfs.btrfs -fq -dsingle -msingle /dev/loop0
$ btrfstune -S 1 /dev/loop0
$ mount /dev/loop0 /btrfs
$ btrfs dev add -f /dev/loop1 /btrfs
BTRFS info (device loop0): relocating block group 290455552 flags system
BTRFS info (device loop0): relocating block group 1048576 flags system
BTRFS info (device loop0): disk added /dev/loop1
$ umount /btrfs
Mount the sprout device and run fstrim:
$ mount /dev/loop1 /btrfs
$ fstrim /btrfs
$ umount /btrfs
Now try to mount the seed device, and it fails:
$ mount /dev/loop0 /btrfs
mount: /btrfs: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error.
Block 5292032 is missing on the readonly seed device:
$ dmesg -kt | tail
<snip>
BTRFS error (device loop0): bad tree block start, want 5292032 have 0
BTRFS warning (device loop0): couldn't read-tree root
BTRFS error (device loop0): open_ctree failed
>From the dump-tree of the seed device (taken before the fstrim). Block
5292032 belonged to the block group starting at 5242880:
$ btrfs inspect dump-tree -e /dev/loop0 | grep -A1 BLOCK_GROUP
<snip>
item 3 key (5242880 BLOCK_GROUP_ITEM 8388608) itemoff 16169 itemsize 24
block group used 114688 chunk_objectid 256 flags METADATA
<snip>
>From the dump-tree of the sprout device (taken before the fstrim).
fstrim used block-group 5242880 to find the related free space to free:
$ btrfs inspect dump-tree -e /dev/loop1 | grep -A1 BLOCK_GROUP
<snip>
item 1 key (5242880 BLOCK_GROUP_ITEM 8388608) itemoff 16226 itemsize 24
block group used 32768 chunk_objectid 256 flags METADATA
<snip>
BPF kernel tracing the fstrim command finds the missing block 5292032
within the range of the discarded blocks as below:
kprobe:btrfs_discard_extent {
printf("freeing start %llu end %llu num_bytes %llu:\n",
arg1, arg1+arg2, arg2);
}
freeing start 5259264 end 5406720 num_bytes 147456
<snip>
Fix this by avoiding the discard command to the readonly seed device.
Reported-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.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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Filipe Manana
|
baa6763123 |
btrfs: fix deadlock when cloning inline extents and low on available space
commit 76a6d5cd74479e7ec8a7f9a29bce63d5549b6b2e upstream.
There are a few cases where cloning an inline extent requires copying data
into a page of the destination inode. For these cases we are allocating
the required data and metadata space while holding a leaf locked. This can
result in a deadlock when we are low on available space because allocating
the space may flush delalloc and two deadlock scenarios can happen:
1) When starting writeback for an inode with a very small dirty range that
fits in an inline extent, we deadlock during the writeback when trying
to insert the inline extent, at cow_file_range_inline(), if the extent
is going to be located in the leaf for which we are already holding a
read lock;
2) After successfully starting writeback, for non-inline extent cases,
the async reclaim thread will hang waiting for an ordered extent to
complete if the ordered extent completion needs to modify the leaf
for which the clone task is holding a read lock (for adding or
replacing file extent items). So the cloning task will wait forever
on the async reclaim thread to make progress, which in turn is
waiting for the ordered extent completion which in turn is waiting
to acquire a write lock on the same leaf.
So fix this by making sure we release the path (and therefore the leaf)
every time we need to copy the inline extent's data into a page of the
destination inode, as by that time we do not need to have the leaf locked.
Fixes:
|
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Josef Bacik
|
0df50d47d1 |
btrfs: abort in rename_exchange if we fail to insert the second ref
commit dc09ef3562726cd520c8338c1640872a60187af5 upstream. Error injection stress uncovered a problem where we'd leave a dangling inode ref if we failed during a rename_exchange. This happens because we insert the inode ref for one side of the rename, and then for the other side. If this second inode ref insert fails we'll leave the first one dangling and leave a corrupt file system behind. Fix this by aborting if we did the insert for the first inode ref. CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Josef Bacik <josef@toxicpanda.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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Josef Bacik
|
48568f3944 |
btrfs: fixup error handling in fixup_inode_link_counts
commit 011b28acf940eb61c000059dd9e2cfcbf52ed96b upstream.
This function has the following pattern
while (1) {
ret = whatever();
if (ret)
goto out;
}
ret = 0
out:
return ret;
However several places in this while loop we simply break; when there's
a problem, thus clearing the return value, and in one case we do a
return -EIO, and leak the memory for the path.
Fix this by re-arranging the loop to deal with ret == 1 coming from
btrfs_search_slot, and then simply delete the
ret = 0;
out:
bit so everybody can break if there is an error, which will allow for
proper error handling to occur.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.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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Josef Bacik
|
466d83fdbb |
btrfs: return errors from btrfs_del_csums in cleanup_ref_head
commit 856bd270dc4db209c779ce1e9555c7641ffbc88e upstream. We are unconditionally returning 0 in cleanup_ref_head, despite the fact that btrfs_del_csums could fail. We need to return the error so the transaction gets aborted properly, fix this by returning ret from btrfs_del_csums in cleanup_ref_head. Reviewed-by: Qu Wenruo <wqu@suse.com> CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Josef Bacik <josef@toxicpanda.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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Josef Bacik
|
5a89982fa2 |
btrfs: fix error handling in btrfs_del_csums
commit b86652be7c83f70bf406bed18ecf55adb9bfb91b upstream.
Error injection stress would sometimes fail with checksums on disk that
did not have a corresponding extent. This occurred because the pattern
in btrfs_del_csums was
while (1) {
ret = btrfs_search_slot();
if (ret < 0)
break;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
If we got an error from btrfs_search_slot we'd clear the error because
we were breaking instead of goto out. Instead of using goto out, simply
handle the cases where we may leave a random value in ret, and get rid
of the
ret = 0;
out:
pattern and simply allow break to have the proper error reporting. With
this fix we properly abort the transaction and do not commit thinking we
successfully deleted the csum.
Reviewed-by: Qu Wenruo <wqu@suse.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.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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Josef Bacik
|
b547a16b24 |
btrfs: mark ordered extent and inode with error if we fail to finish
commit d61bec08b904cf171835db98168f82bc338e92e4 upstream. While doing error injection testing I saw that sometimes we'd get an abort that wouldn't stop the current transaction commit from completing. This abort was coming from finish ordered IO, but at this point in the transaction commit we should have gotten an error and stopped. It turns out the abort came from finish ordered io while trying to write out the free space cache. It occurred to me that any failure inside of finish_ordered_io isn't actually raised to the person doing the writing, so we could have any number of failures in this path and think the ordered extent completed successfully and the inode was fine. Fix this by marking the ordered extent with BTRFS_ORDERED_IOERR, and marking the mapping of the inode with mapping_set_error, so any callers that simply call fdatawait will also get the error. With this we're seeing the IO error on the free space inode when we fail to do the finish_ordered_io. CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Josef Bacik <josef@toxicpanda.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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|
Josef Bacik
|
1d62b7ac83 |
btrfs: tree-checker: do not error out if extent ref hash doesn't match
commit 1119a72e223f3073a604f8fccb3a470ccd8a4416 upstream.
The tree checker checks the extent ref hash at read and write time to
make sure we do not corrupt the file system. Generally extent
references go inline, but if we have enough of them we need to make an
item, which looks like
key.objectid = <bytenr>
key.type = <BTRFS_EXTENT_DATA_REF_KEY|BTRFS_TREE_BLOCK_REF_KEY>
key.offset = hash(tree, owner, offset)
However if key.offset collide with an unrelated extent reference we'll
simply key.offset++ until we get something that doesn't collide.
Obviously this doesn't match at tree checker time, and thus we error
while writing out the transaction. This is relatively easy to
reproduce, simply do something like the following
xfs_io -f -c "pwrite 0 1M" file
offset=2
for i in {0..10000}
do
xfs_io -c "reflink file 0 ${offset}M 1M" file
offset=$(( offset + 2 ))
done
xfs_io -c "reflink file 0 17999258914816 1M" file
xfs_io -c "reflink file 0 35998517829632 1M" file
xfs_io -c "reflink file 0 53752752058368 1M" file
btrfs filesystem sync
And the sync will error out because we'll abort the transaction. The
magic values above are used because they generate hash collisions with
the first file in the main subvol.
The fix for this is to remove the hash value check from tree checker, as
we have no idea which offset ours should belong to.
Reported-by: Tuomas Lähdekorpi <tuomas.lahdekorpi@gmail.com>
Fixes:
|
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|
Josef Bacik
|
7e13db5039 |
btrfs: do not BUG_ON in link_to_fixup_dir
[ Upstream commit 91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d ] While doing error injection testing I got the following panic kernel BUG at fs/btrfs/tree-log.c:1862! invalid opcode: 0000 [#1] SMP NOPTI CPU: 1 PID: 7836 Comm: mount Not tainted 5.13.0-rc1+ #305 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:link_to_fixup_dir+0xd5/0xe0 RSP: 0018:ffffb5800180fa30 EFLAGS: 00010216 RAX: fffffffffffffffb RBX: 00000000fffffffb RCX: ffff8f595287faf0 RDX: ffffb5800180fa37 RSI: ffff8f5954978800 RDI: 0000000000000000 RBP: ffff8f5953af9450 R08: 0000000000000019 R09: 0000000000000001 R10: 000151f408682970 R11: 0000000120021001 R12: ffff8f5954978800 R13: ffff8f595287faf0 R14: ffff8f5953c77dd0 R15: 0000000000000065 FS: 00007fc5284c8c40(0000) GS:ffff8f59bbd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc5287f47c0 CR3: 000000011275e002 CR4: 0000000000370ee0 Call Trace: replay_one_buffer+0x409/0x470 ? btree_read_extent_buffer_pages+0xd0/0x110 walk_up_log_tree+0x157/0x1e0 walk_log_tree+0xa6/0x1d0 btrfs_recover_log_trees+0x1da/0x360 ? replay_one_extent+0x7b0/0x7b0 open_ctree+0x1486/0x1720 btrfs_mount_root.cold+0x12/0xea ? __kmalloc_track_caller+0x12f/0x240 legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 ? vfs_parse_fs_string+0x4d/0x90 legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 path_mount+0x433/0xa10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae We can get -EIO or any number of legitimate errors from btrfs_search_slot(), panicing here is not the appropriate response. The error path for this code handles errors properly, simply return the error. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
|
Filipe Manana
|
88f566beb1 |
btrfs: release path before starting transaction when cloning inline extent
[ Upstream commit 6416954ca75baed71640bf3828625bf165fb9b5e ] When cloning an inline extent there are a few cases, such as when we have an implicit hole at file offset 0, where we start a transaction while holding a read lock on a leaf. Starting the transaction results in a call to sb_start_intwrite(), which results in doing a read lock on a percpu semaphore. Lockdep doesn't like this and complains about it: [46.580704] ====================================================== [46.580752] WARNING: possible circular locking dependency detected [46.580799] 5.13.0-rc1 #28 Not tainted [46.580832] ------------------------------------------------------ [46.580877] cloner/3835 is trying to acquire lock: [46.580918] c00000001301d638 (sb_internal#2){.+.+}-{0:0}, at: clone_copy_inline_extent+0xe4/0x5a0 [46.581167] [46.581167] but task is already holding lock: [46.581217] c000000007fa2550 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x70/0x1d0 [46.581293] [46.581293] which lock already depends on the new lock. [46.581293] [46.581351] [46.581351] the existing dependency chain (in reverse order) is: [46.581410] [46.581410] -> #1 (btrfs-tree-00){++++}-{3:3}: [46.581464] down_read_nested+0x68/0x200 [46.581536] __btrfs_tree_read_lock+0x70/0x1d0 [46.581577] btrfs_read_lock_root_node+0x88/0x200 [46.581623] btrfs_search_slot+0x298/0xb70 [46.581665] btrfs_set_inode_index+0xfc/0x260 [46.581708] btrfs_new_inode+0x26c/0x950 [46.581749] btrfs_create+0xf4/0x2b0 [46.581782] lookup_open.isra.57+0x55c/0x6a0 [46.581855] path_openat+0x418/0xd20 [46.581888] do_filp_open+0x9c/0x130 [46.581920] do_sys_openat2+0x2ec/0x430 [46.581961] do_sys_open+0x90/0xc0 [46.581993] system_call_exception+0x3d4/0x410 [46.582037] system_call_common+0xec/0x278 [46.582078] [46.582078] -> #0 (sb_internal#2){.+.+}-{0:0}: [46.582135] __lock_acquire+0x1e90/0x2c50 [46.582176] lock_acquire+0x2b4/0x5b0 [46.582263] start_transaction+0x3cc/0x950 [46.582308] clone_copy_inline_extent+0xe4/0x5a0 [46.582353] btrfs_clone+0x5fc/0x880 [46.582388] btrfs_clone_files+0xd8/0x1c0 [46.582434] btrfs_remap_file_range+0x3d8/0x590 [46.582481] do_clone_file_range+0x10c/0x270 [46.582558] vfs_clone_file_range+0x1b0/0x310 [46.582605] ioctl_file_clone+0x90/0x130 [46.582651] do_vfs_ioctl+0x874/0x1ac0 [46.582697] sys_ioctl+0x6c/0x120 [46.582733] system_call_exception+0x3d4/0x410 [46.582777] system_call_common+0xec/0x278 [46.582822] [46.582822] other info that might help us debug this: [46.582822] [46.582888] Possible unsafe locking scenario: [46.582888] [46.582942] CPU0 CPU1 [46.582984] ---- ---- [46.583028] lock(btrfs-tree-00); [46.583062] lock(sb_internal#2); [46.583119] lock(btrfs-tree-00); [46.583174] lock(sb_internal#2); [46.583212] [46.583212] *** DEADLOCK *** [46.583212] [46.583266] 6 locks held by cloner/3835: [46.583299] #0: c00000001301d448 (sb_writers#12){.+.+}-{0:0}, at: ioctl_file_clone+0x90/0x130 [46.583382] #1: c00000000f6d3768 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: lock_two_nondirectories+0x58/0xc0 [46.583477] #2: c00000000f6d72a8 (&sb->s_type->i_mutex_key#15/4){+.+.}-{3:3}, at: lock_two_nondirectories+0x9c/0xc0 [46.583574] #3: c00000000f6d7138 (&ei->i_mmap_lock){+.+.}-{3:3}, at: btrfs_remap_file_range+0xd0/0x590 [46.583657] #4: c00000000f6d35f8 (&ei->i_mmap_lock/1){+.+.}-{3:3}, at: btrfs_remap_file_range+0xe0/0x590 [46.583743] #5: c000000007fa2550 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x70/0x1d0 [46.583828] [46.583828] stack backtrace: [46.583872] CPU: 1 PID: 3835 Comm: cloner Not tainted 5.13.0-rc1 #28 [46.583931] Call Trace: [46.583955] [c0000000167c7200] [c000000000c1ee78] dump_stack+0xec/0x144 (unreliable) [46.584052] [c0000000167c7240] [c000000000274058] print_circular_bug.isra.32+0x3a8/0x400 [46.584123] [c0000000167c72e0] [c0000000002741f4] check_noncircular+0x144/0x190 [46.584191] [c0000000167c73b0] [c000000000278fc0] __lock_acquire+0x1e90/0x2c50 [46.584259] [c0000000167c74f0] [c00000000027aa94] lock_acquire+0x2b4/0x5b0 [46.584317] [c0000000167c75e0] [c000000000a0d6cc] start_transaction+0x3cc/0x950 [46.584388] [c0000000167c7690] [c000000000af47a4] clone_copy_inline_extent+0xe4/0x5a0 [46.584457] [c0000000167c77c0] [c000000000af525c] btrfs_clone+0x5fc/0x880 [46.584514] [c0000000167c7990] [c000000000af5698] btrfs_clone_files+0xd8/0x1c0 [46.584583] [c0000000167c7a00] [c000000000af5b58] btrfs_remap_file_range+0x3d8/0x590 [46.584652] [c0000000167c7ae0] [c0000000005d81dc] do_clone_file_range+0x10c/0x270 [46.584722] [c0000000167c7b40] [c0000000005d84f0] vfs_clone_file_range+0x1b0/0x310 [46.584793] [c0000000167c7bb0] [c00000000058bf80] ioctl_file_clone+0x90/0x130 [46.584861] [c0000000167c7c10] [c00000000058c894] do_vfs_ioctl+0x874/0x1ac0 [46.584922] [c0000000167c7d10] [c00000000058db4c] sys_ioctl+0x6c/0x120 [46.584978] [c0000000167c7d60] [c0000000000364a4] system_call_exception+0x3d4/0x410 [46.585046] [c0000000167c7e10] [c00000000000d45c] system_call_common+0xec/0x278 [46.585114] --- interrupt: c00 at 0x7ffff7e22990 [46.585160] NIP: 00007ffff7e22990 LR: 00000001000010ec CTR: 0000000000000000 [46.585224] REGS: c0000000167c7e80 TRAP: 0c00 Not tainted (5.13.0-rc1) [46.585280] MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 28000244 XER: 00000000 [46.585374] IRQMASK: 0 [46.585374] GPR00: 0000000000000036 00007fffffffdec0 00007ffff7f17100 0000000000000004 [46.585374] GPR04: 000000008020940d 00007fffffffdf40 0000000000000000 0000000000000000 [46.585374] GPR08: 0000000000000004 0000000000000000 0000000000000000 0000000000000000 [46.585374] GPR12: 0000000000000000 00007ffff7ffa940 0000000000000000 0000000000000000 [46.585374] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [46.585374] GPR20: 0000000000000000 000000009123683e 00007fffffffdf40 0000000000000000 [46.585374] GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000004 [46.585374] GPR28: 0000000100030260 0000000100030280 0000000000000003 000000000000005f [46.585919] NIP [00007ffff7e22990] 0x7ffff7e22990 [46.585964] LR [00000001000010ec] 0x1000010ec [46.586010] --- interrupt: c00 This should be a false positive, as both locks are acquired in read mode. Nevertheless, we don't need to hold a leaf locked when we start the transaction, so just release the leaf (path) before starting it. Reported-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/linux-btrfs/20210513214404.xks77p566fglzgum@riteshh-domain/ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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|
Boris Burkov
|
c7e0c6047c |
btrfs: return whole extents in fiemap
[ Upstream commit 15c7745c9a0078edad1f7df5a6bb7b80bc8cca23 ]
`xfs_io -c 'fiemap <off> <len>' <file>`
can give surprising results on btrfs that differ from xfs.
btrfs prints out extents trimmed to fit the user input. If the user's
fiemap request has an offset, then rather than returning each whole
extent which intersects that range, we also trim the start extent to not
have start < off.
Documentation in filesystems/fiemap.txt and the xfs_io man page suggests
that returning the whole extent is expected.
Some cases which all yield the same fiemap in xfs, but not btrfs:
dd if=/dev/zero of=$f bs=4k count=1
sudo xfs_io -c 'fiemap 0 1024' $f
0: [0..7]: 26624..26631
sudo xfs_io -c 'fiemap 2048 1024' $f
0: [4..7]: 26628..26631
sudo xfs_io -c 'fiemap 2048 4096' $f
0: [4..7]: 26628..26631
sudo xfs_io -c 'fiemap 3584 512' $f
0: [7..7]: 26631..26631
sudo xfs_io -c 'fiemap 4091 5' $f
0: [7..6]: 26631..26630
I believe this is a consequence of the logic for merging contiguous
extents represented by separate extent items. That logic needs to track
the last offset as it loops through the extent items, which happens to
pick up the start offset on the first iteration, and trim off the
beginning of the full extent. To fix it, start `off` at 0 rather than
`start` so that we keep the iteration/merging intact without cutting off
the start of the extent.
after the fix, all the above commands give:
0: [0..7]: 26624..26631
The merging logic is exercised by fstest generic/483, and I have written
a new fstest for checking we don't have backwards or zero-length fiemaps
for cases like those above.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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Josef Bacik
|
56001dda03 |
btrfs: avoid RCU stalls while running delayed iputs
commit 71795ee590111e3636cc3c148289dfa9fa0a5fc3 upstream. Generally a delayed iput is added when we might do the final iput, so usually we'll end up sleeping while processing the delayed iputs naturally. However there's no guarantee of this, especially for small files. In production we noticed 5 instances of RCU stalls while testing a kernel release overnight across 1000 machines, so this is relatively common: host count: 5 rcu: INFO: rcu_sched self-detected stall on CPU rcu: ....: (20998 ticks this GP) idle=59e/1/0x4000000000000002 softirq=12333372/12333372 fqs=3208 (t=21031 jiffies g=27810193 q=41075) NMI backtrace for cpu 1 CPU: 1 PID: 1713 Comm: btrfs-cleaner Kdump: loaded Not tainted 5.6.13-0_fbk12_rc1_5520_gec92bffc1ec9 #1 Call Trace: <IRQ> dump_stack+0x50/0x70 nmi_cpu_backtrace.cold.6+0x30/0x65 ? lapic_can_unplug_cpu.cold.30+0x40/0x40 nmi_trigger_cpumask_backtrace+0xba/0xca rcu_dump_cpu_stacks+0x99/0xc7 rcu_sched_clock_irq.cold.90+0x1b2/0x3a3 ? trigger_load_balance+0x5c/0x200 ? tick_sched_do_timer+0x60/0x60 ? tick_sched_do_timer+0x60/0x60 update_process_times+0x24/0x50 tick_sched_timer+0x37/0x70 __hrtimer_run_queues+0xfe/0x270 hrtimer_interrupt+0xf4/0x210 smp_apic_timer_interrupt+0x5e/0x120 apic_timer_interrupt+0xf/0x20 </IRQ> RIP: 0010:queued_spin_lock_slowpath+0x17d/0x1b0 RSP: 0018:ffffc9000da5fe48 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffff889fa81d0cd8 RCX: 0000000000000029 RDX: ffff889fff86c0c0 RSI: 0000000000080000 RDI: ffff88bfc2da7200 RBP: ffff888f2dcdd768 R08: 0000000001040000 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff82a55560 R12: ffff88bfc2da7200 R13: 0000000000000000 R14: ffff88bff6c2a360 R15: ffffffff814bd870 ? kzalloc.constprop.57+0x30/0x30 list_lru_add+0x5a/0x100 inode_lru_list_add+0x20/0x40 iput+0x1c1/0x1f0 run_delayed_iput_locked+0x46/0x90 btrfs_run_delayed_iputs+0x3f/0x60 cleaner_kthread+0xf2/0x120 kthread+0x10b/0x130 Fix this by adding a cond_resched_lock() to the loop processing delayed iputs so we can avoid these sort of stalls. CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Josef Bacik <josef@toxicpanda.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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|
Filipe Manana
|
bccb7dd137 |
btrfs: fix race leading to unpersisted data and metadata on fsync
commit 626e9f41f7c281ba3e02843702f68471706aa6d9 upstream.
When doing a fast fsync on a file, there is a race which can result in the
fsync returning success to user space without logging the inode and without
durably persisting new data.
The following example shows one possible scenario for this:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ touch /mnt/bar
$ xfs_io -f -c "pwrite -S 0xab 0 1M" -c "fsync" /mnt/baz
# Now we have:
# file bar == inode 257
# file baz == inode 258
$ mv /mnt/baz /mnt/foo
# Now we have:
# file bar == inode 257
# file foo == inode 258
$ xfs_io -c "pwrite -S 0xcd 0 1M" /mnt/foo
# fsync bar before foo, it is important to trigger the race.
$ xfs_io -c "fsync" /mnt/bar
$ xfs_io -c "fsync" /mnt/foo
# After this:
# inode 257, file bar, is empty
# inode 258, file foo, has 1M filled with 0xcd
<power failure>
# Replay the log:
$ mount /dev/sdc /mnt
# After this point file foo should have 1M filled with 0xcd and not 0xab
The following steps explain how the race happens:
1) Before the first fsync of inode 258, when it has the "baz" name, its
->logged_trans is 0, ->last_sub_trans is 0 and ->last_log_commit is -1.
The inode also has the full sync flag set;
2) After the first fsync, we set inode 258 ->logged_trans to 6, which is
the generation of the current transaction, and set ->last_log_commit
to 0, which is the current value of ->last_sub_trans (done at
btrfs_log_inode()).
The full sync flag is cleared from the inode during the fsync.
The log sub transaction that was committed had an ID of 0 and when we
synced the log, at btrfs_sync_log(), we incremented root->log_transid
from 0 to 1;
3) During the rename:
We update inode 258, through btrfs_update_inode(), and that causes its
->last_sub_trans to be set to 1 (the current log transaction ID), and
->last_log_commit remains with a value of 0.
After updating inode 258, because we have previously logged the inode
in the previous fsync, we log again the inode through the call to
btrfs_log_new_name(). This results in updating the inode's
->last_log_commit from 0 to 1 (the current value of its
->last_sub_trans).
The ->last_sub_trans of inode 257 is updated to 1, which is the ID of
the next log transaction;
4) Then a buffered write against inode 258 is made. This leaves the value
of ->last_sub_trans as 1 (the ID of the current log transaction, stored
at root->log_transid);
5) Then an fsync against inode 257 (or any other inode other than 258),
happens. This results in committing the log transaction with ID 1,
which results in updating root->last_log_commit to 1 and bumping
root->log_transid from 1 to 2;
6) Then an fsync against inode 258 starts. We flush delalloc and wait only
for writeback to complete, since the full sync flag is not set in the
inode's runtime flags - we do not wait for ordered extents to complete.
Then, at btrfs_sync_file(), we call btrfs_inode_in_log() before the
ordered extent completes. The call returns true:
static inline bool btrfs_inode_in_log(...)
{
bool ret = false;
spin_lock(&inode->lock);
if (inode->logged_trans == generation &&
inode->last_sub_trans <= inode->last_log_commit &&
inode->last_sub_trans <= inode->root->last_log_commit)
ret = true;
spin_unlock(&inode->lock);
return ret;
}
generation has a value of 6 (fs_info->generation), ->logged_trans also
has a value of 6 (set when we logged the inode during the first fsync
and when logging it during the rename), ->last_sub_trans has a value
of 1, set during the rename (step 3), ->last_log_commit also has a
value of 1 (set in step 3) and root->last_log_commit has a value of 1,
which was set in step 5 when fsyncing inode 257.
As a consequence we don't log the inode, any new extents and do not
sync the log, resulting in a data loss if a power failure happens
after the fsync and before the current transaction commits.
Also, because we do not log the inode, after a power failure the mtime
and ctime of the inode do not match those we had before.
When the ordered extent completes before we call btrfs_inode_in_log(),
then the call returns false and we log the inode and sync the log,
since at the end of ordered extent completion we update the inode and
set ->last_sub_trans to 2 (the value of root->log_transid) and
->last_log_commit to 1.
This problem is found after removing the check for the emptiness of the
inode's list of modified extents in the recent commit 209ecbb8585bf6
("btrfs: remove stale comment and logic from btrfs_inode_in_log()"),
added in the 5.13 merge window. However checking the emptiness of the
list is not really the way to solve this problem, and was never intended
to, because while that solves the problem for COW writes, the problem
persists for NOCOW writes because in that case the list is always empty.
In the case of NOCOW writes, even though we wait for the writeback to
complete before returning from btrfs_sync_file(), we end up not logging
the inode, which has a new mtime/ctime, and because we don't sync the log,
we never issue disk barriers (send REQ_PREFLUSH to the device) since that
only happens when we sync the log (when we write super blocks at
btrfs_sync_log()). So effectively, for a NOCOW case, when we return from
btrfs_sync_file() to user space, we are not guaranteeing that the data is
durably persisted on disk.
Also, while the example above uses a rename exchange to show how the
problem happens, it is not the only way to trigger it. An alternative
could be adding a new hard link to inode 258, since that also results
in calling btrfs_log_new_name() and updating the inode in the log.
An example reproducer using the addition of a hard link instead of a
rename operation:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ touch /mnt/bar
$ xfs_io -f -c "pwrite -S 0xab 0 1M" -c "fsync" /mnt/foo
$ ln /mnt/foo /mnt/foo_link
$ xfs_io -c "pwrite -S 0xcd 0 1M" /mnt/foo
$ xfs_io -c "fsync" /mnt/bar
$ xfs_io -c "fsync" /mnt/foo
<power failure>
# Replay the log:
$ mount /dev/sdc /mnt
# After this point file foo often has 1M filled with 0xab and not 0xcd
The reasons leading to the final fsync of file foo, inode 258, not
persisting the new data are the same as for the previous example with
a rename operation.
So fix by never skipping logging and log syncing when there are still any
ordered extents in flight. To avoid making the conditional if statement
that checks if logging an inode is needed harder to read, place all the
logic into an helper function with separate if statements to make it more
manageable and easier to read.
A test case for fstests will follow soon.
For NOCOW writes, the problem existed before commit
|
||
|
Filipe Manana
|
1d852d6bb4 |
btrfs: fix race when picking most recent mod log operation for an old root
[ Upstream commit f9690f426b2134cc3e74bfc5d9dfd6a4b2ca5281 ]
Commit dbcc7d57bffc0c ("btrfs: fix race when cloning extent buffer during
rewind of an old root"), fixed a race when we need to rewind the extent
buffer of an old root. It was caused by picking a new mod log operation
for the extent buffer while getting a cloned extent buffer with an outdated
number of items (off by -1), because we cloned the extent buffer without
locking it first.
However there is still another similar race, but in the opposite direction.
The cloned extent buffer has a number of items that does not match the
number of tree mod log operations that are going to be replayed. This is
because right after we got the last (most recent) tree mod log operation to
replay and before locking and cloning the extent buffer, another task adds
a new pointer to the extent buffer, which results in adding a new tree mod
log operation and incrementing the number of items in the extent buffer.
So after cloning we have mismatch between the number of items in the extent
buffer and the number of mod log operations we are going to apply to it.
This results in hitting a BUG_ON() that produces the following stack trace:
------------[ cut here ]------------
kernel BUG at fs/btrfs/tree-mod-log.c:675!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 3 PID: 4811 Comm: crawl_1215 Tainted: G W 5.12.0-7d1efdf501f8-misc-next+ #99
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:tree_mod_log_rewind+0x3b1/0x3c0
Code: 05 48 8d 74 10 (...)
RSP: 0018:ffffc90001027090 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880a8514600 RCX: ffffffffaa9e59b6
RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8880a851462c
RBP: ffffc900010270e0 R08: 00000000000000c0 R09: ffffed1004333417
R10: ffff88802199a0b7 R11: ffffed1004333416 R12: 000000000000000e
R13: ffff888135af8748 R14: ffff88818766ff00 R15: ffff8880a851462c
FS: 00007f29acf62700(0000) GS:ffff8881f2200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0e6013f718 CR3: 000000010d42e003 CR4: 0000000000170ee0
Call Trace:
btrfs_get_old_root+0x16a/0x5c0
? lock_downgrade+0x400/0x400
btrfs_search_old_slot+0x192/0x520
? btrfs_search_slot+0x1090/0x1090
? free_extent_buffer.part.61+0xd7/0x140
? free_extent_buffer+0x13/0x20
resolve_indirect_refs+0x3e9/0xfc0
? lock_downgrade+0x400/0x400
? __kasan_check_read+0x11/0x20
? add_prelim_ref.part.11+0x150/0x150
? lock_downgrade+0x400/0x400
? __kasan_check_read+0x11/0x20
? lock_acquired+0xbb/0x620
? __kasan_check_write+0x14/0x20
? do_raw_spin_unlock+0xa8/0x140
? rb_insert_color+0x340/0x360
? prelim_ref_insert+0x12d/0x430
find_parent_nodes+0x5c3/0x1830
? stack_trace_save+0x87/0xb0
? resolve_indirect_refs+0xfc0/0xfc0
? fs_reclaim_acquire+0x67/0xf0
? __kasan_check_read+0x11/0x20
? lockdep_hardirqs_on_prepare+0x210/0x210
? fs_reclaim_acquire+0x67/0xf0
? __kasan_check_read+0x11/0x20
? ___might_sleep+0x10f/0x1e0
? __kasan_kmalloc+0x9d/0xd0
? trace_hardirqs_on+0x55/0x120
btrfs_find_all_roots_safe+0x142/0x1e0
? find_parent_nodes+0x1830/0x1830
? trace_hardirqs_on+0x55/0x120
? ulist_free+0x1f/0x30
? btrfs_inode_flags_to_xflags+0x50/0x50
iterate_extent_inodes+0x20e/0x580
? tree_backref_for_extent+0x230/0x230
? release_extent_buffer+0x225/0x280
? read_extent_buffer+0xdd/0x110
? lock_downgrade+0x400/0x400
? __kasan_check_read+0x11/0x20
? lock_acquired+0xbb/0x620
? __kasan_check_write+0x14/0x20
? do_raw_spin_unlock+0xa8/0x140
? _raw_spin_unlock+0x22/0x30
? release_extent_buffer+0x225/0x280
iterate_inodes_from_logical+0x129/0x170
? iterate_inodes_from_logical+0x129/0x170
? btrfs_inode_flags_to_xflags+0x50/0x50
? iterate_extent_inodes+0x580/0x580
? __vmalloc_node+0x92/0xb0
? init_data_container+0x34/0xb0
? init_data_container+0x34/0xb0
? kvmalloc_node+0x60/0x80
btrfs_ioctl_logical_to_ino+0x158/0x230
btrfs_ioctl+0x2038/0x4360
? __kasan_check_write+0x14/0x20
? mmput+0x3b/0x220
? btrfs_ioctl_get_supported_features+0x30/0x30
? __kasan_check_read+0x11/0x20
? __kasan_check_read+0x11/0x20
? lock_release+0xc8/0x650
? __might_fault+0x64/0xd0
? __kasan_check_read+0x11/0x20
? lock_downgrade+0x400/0x400
? lockdep_hardirqs_on_prepare+0x210/0x210
? lockdep_hardirqs_on_prepare+0x13/0x210
? _raw_spin_unlock_irqrestore+0x51/0x63
? __kasan_check_read+0x11/0x20
? do_vfs_ioctl+0xfc/0x9d0
? ioctl_file_clone+0xe0/0xe0
? lock_downgrade+0x400/0x400
? lockdep_hardirqs_on_prepare+0x210/0x210
? __kasan_check_read+0x11/0x20
? lock_release+0xc8/0x650
? __task_pid_nr_ns+0xd3/0x250
? __kasan_check_read+0x11/0x20
? __fget_files+0x160/0x230
? __fget_light+0xf2/0x110
__x64_sys_ioctl+0xc3/0x100
do_syscall_64+0x37/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f29ae85b427
Code: 00 00 90 48 8b (...)
RSP: 002b:00007f29acf5fcf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f29acf5ff40 RCX: 00007f29ae85b427
RDX: 00007f29acf5ff48 RSI: 00000000c038943b RDI: 0000000000000003
RBP: 0000000001000000 R08: 0000000000000000 R09: 00007f29acf60120
R10: 00005640d5fc7b00 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f29acf5ff48 R14: 00007f29acf5ff40 R15: 00007f29acf5fef8
Modules linked in:
---[ end trace 85e5fce078dfbe04 ]---
(gdb) l *(tree_mod_log_rewind+0x3b1)
0xffffffff819e5b21 is in tree_mod_log_rewind (fs/btrfs/tree-mod-log.c:675).
670 * the modification. As we're going backwards, we do the
671 * opposite of each operation here.
672 */
673 switch (tm->op) {
674 case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING:
675 BUG_ON(tm->slot < n);
676 fallthrough;
677 case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING:
678 case BTRFS_MOD_LOG_KEY_REMOVE:
679 btrfs_set_node_key(eb, &tm->key, tm->slot);
(gdb) quit
The following steps explain in more detail how it happens:
1) We have one tree mod log user (through fiemap or the logical ino ioctl),
with a sequence number of 1, so we have fs_info->tree_mod_seq == 1.
This is task A;
2) Another task is at ctree.c:balance_level() and we have eb X currently as
the root of the tree, and we promote its single child, eb Y, as the new
root.
Then, at ctree.c:balance_level(), we call:
ret = btrfs_tree_mod_log_insert_root(root->node, child, true);
3) At btrfs_tree_mod_log_insert_root() we create a tree mod log operation
of type BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING, with a ->logical field
pointing to ebX->start. We only have one item in eb X, so we create
only one tree mod log operation, and store in the "tm_list" array;
4) Then, still at btrfs_tree_mod_log_insert_root(), we create a tree mod
log element of operation type BTRFS_MOD_LOG_ROOT_REPLACE, ->logical set
to ebY->start, ->old_root.logical set to ebX->start, ->old_root.level
set to the level of eb X and ->generation set to the generation of eb X;
5) Then btrfs_tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
"tm_list" as argument. After that, tree_mod_log_free_eb() calls
tree_mod_log_insert(). This inserts the mod log operation of type
BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING from step 3 into the rbtree
with a sequence number of 2 (and fs_info->tree_mod_seq set to 2);
6) Then, after inserting the "tm_list" single element into the tree mod
log rbtree, the BTRFS_MOD_LOG_ROOT_REPLACE element is inserted, which
gets the sequence number 3 (and fs_info->tree_mod_seq set to 3);
7) Back to ctree.c:balance_level(), we free eb X by calling
btrfs_free_tree_block() on it. Because eb X was created in the current
transaction, has no other references and writeback did not happen for
it, we add it back to the free space cache/tree;
8) Later some other task B allocates the metadata extent from eb X, since
it is marked as free space in the space cache/tree, and uses it as a
node for some other btree;
9) The tree mod log user task calls btrfs_search_old_slot(), which calls
btrfs_get_old_root(), and finally that calls tree_mod_log_oldest_root()
with time_seq == 1 and eb_root == eb Y;
10) The first iteration of the while loop finds the tree mod log element
with sequence number 3, for the logical address of eb Y and of type
BTRFS_MOD_LOG_ROOT_REPLACE;
11) Because the operation type is BTRFS_MOD_LOG_ROOT_REPLACE, we don't
break out of the loop, and set root_logical to point to
tm->old_root.logical, which corresponds to the logical address of
eb X;
12) On the next iteration of the while loop, the call to
tree_mod_log_search_oldest() returns the smallest tree mod log element
for the logical address of eb X, which has a sequence number of 2, an
operation type of BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING and
corresponds to the old slot 0 of eb X (eb X had only 1 item in it
before being freed at step 7);
13) We then break out of the while loop and return the tree mod log
operation of type BTRFS_MOD_LOG_ROOT_REPLACE (eb Y), and not the one
for slot 0 of eb X, to btrfs_get_old_root();
14) At btrfs_get_old_root(), we process the BTRFS_MOD_LOG_ROOT_REPLACE
operation and set "logical" to the logical address of eb X, which was
the old root. We then call tree_mod_log_search() passing it the logical
address of eb X and time_seq == 1;
15) But before calling tree_mod_log_search(), task B locks eb X, adds a
key to eb X, which results in adding a tree mod log operation of type
BTRFS_MOD_LOG_KEY_ADD, with a sequence number of 4, to the tree mod
log, and increments the number of items in eb X from 0 to 1.
Now fs_info->tree_mod_seq has a value of 4;
16) Task A then calls tree_mod_log_search(), which returns the most recent
tree mod log operation for eb X, which is the one just added by task B
at the previous step, with a sequence number of 4, a type of
BTRFS_MOD_LOG_KEY_ADD and for slot 0;
17) Before task A locks and clones eb X, task A adds another key to eb X,
which results in adding a new BTRFS_MOD_LOG_KEY_ADD mod log operation,
with a sequence number of 5, for slot 1 of eb X, increments the
number of items in eb X from 1 to 2, and unlocks eb X.
Now fs_info->tree_mod_seq has a value of 5;
18) Task A then locks eb X and clones it. The clone has a value of 2 for
the number of items and the pointer "tm" points to the tree mod log
operation with sequence number 4, not the most recent one with a
sequence number of 5, so there is mismatch between the number of
mod log operations that are going to be applied to the cloned version
of eb X and the number of items in the clone;
19) Task A then calls tree_mod_log_rewind() with the clone of eb X, the
tree mod log operation with sequence number 4 and a type of
BTRFS_MOD_LOG_KEY_ADD, and time_seq == 1;
20) At tree_mod_log_rewind(), we set the local variable "n" with a value
of 2, which is the number of items in the clone of eb X.
Then in the first iteration of the while loop, we process the mod log
operation with sequence number 4, which is targeted at slot 0 and has
a type of BTRFS_MOD_LOG_KEY_ADD. This results in decrementing "n" from
2 to 1.
Then we pick the next tree mod log operation for eb X, which is the
tree mod log operation with a sequence number of 2, a type of
BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING and for slot 0, it is the one
added in step 5 to the tree mod log tree.
We go back to the top of the loop to process this mod log operation,
and because its slot is 0 and "n" has a value of 1, we hit the BUG_ON:
(...)
switch (tm->op) {
case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING:
BUG_ON(tm->slot < n);
fallthrough;
(...)
Fix this by checking for a more recent tree mod log operation after locking
and cloning the extent buffer of the old root node, and use it as the first
operation to apply to the cloned extent buffer when rewinding it.
Stable backport notes: due to moved code and renames, in =< 5.11 the
change should be applied to ctree.c:get_old_root.
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210404040732.GZ32440@hungrycats.org/
Fixes:
|
||
|
Josef Bacik
|
9c60c881d6 |
btrfs: convert logic BUG_ON()'s in replace_path to ASSERT()'s
[ Upstream commit 7a9213a93546e7eaef90e6e153af6b8fc7553f10 ] A few BUG_ON()'s in replace_path are purely to keep us from making logical mistakes, so replace them with ASSERT()'s. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
|
Josef Bacik
|
f32b84d7c9 |
btrfs: do proper error handling in btrfs_update_reloc_root
[ Upstream commit 592fbcd50c99b8adf999a2a54f9245caff333139 ] We call btrfs_update_root in btrfs_update_reloc_root, which can fail for all sorts of reasons, including IO errors. Instead of panicing the box lets return the error, now that all callers properly handle those errors. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
|
Josef Bacik
|
224c654a2e |
btrfs: do proper error handling in create_reloc_root
[ Upstream commit 84c50ba5214c2f3c1be4a931d521ec19f55dfdc8 ] We do memory allocations here, read blocks from disk, all sorts of operations that could easily fail at any given point. Instead of panicing the box, simply return the error back up the chain, all callers at this point have proper error handling. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
|
Filipe Manana
|
a4794be7b0 |
btrfs: fix race between transaction aborts and fsyncs leading to use-after-free
commit 061dde8245356d8864d29e25207aa4daa0be4d3c upstream.
There is a race between a task aborting a transaction during a commit,
a task doing an fsync and the transaction kthread, which leads to an
use-after-free of the log root tree. When this happens, it results in a
stack trace like the following:
BTRFS info (device dm-0): forced readonly
BTRFS warning (device dm-0): Skipping commit of aborted transaction.
BTRFS: error (device dm-0) in cleanup_transaction:1958: errno=-5 IO failure
BTRFS warning (device dm-0): lost page write due to IO error on /dev/mapper/error-test (-5)
BTRFS warning (device dm-0): Skipping commit of aborted transaction.
BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0xa4e8 len 4096 err no 10
BTRFS error (device dm-0): error writing primary super block to device 1
BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e000 len 4096 err no 10
BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e008 len 4096 err no 10
BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e010 len 4096 err no 10
BTRFS: error (device dm-0) in write_all_supers:4110: errno=-5 IO failure (1 errors while writing supers)
BTRFS: error (device dm-0) in btrfs_sync_log:3308: errno=-5 IO failure
general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b68: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 2 PID: 2458471 Comm: fsstress Not tainted 5.12.0-rc5-btrfs-next-84 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:__mutex_lock+0x139/0xa40
Code: c0 74 19 (...)
RSP: 0018:ffff9f18830d7b00 EFLAGS: 00010202
RAX: 6b6b6b6b6b6b6b68 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffffffffb9c54d13 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff9f18830d7bc0 R08: 0000000000000000 R09: 0000000000000000
R10: ffff9f18830d7be0 R11: 0000000000000001 R12: ffff8c6cd199c040
R13: ffff8c6c95821358 R14: 00000000fffffffb R15: ffff8c6cbcf01358
FS: 00007fa9140c2b80(0000) GS:ffff8c6fac600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa913d52000 CR3: 000000013d2b4003 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? __btrfs_handle_fs_error+0xde/0x146 [btrfs]
? btrfs_sync_log+0x7c1/0xf20 [btrfs]
? btrfs_sync_log+0x7c1/0xf20 [btrfs]
btrfs_sync_log+0x7c1/0xf20 [btrfs]
btrfs_sync_file+0x40c/0x580 [btrfs]
do_fsync+0x38/0x70
__x64_sys_fsync+0x10/0x20
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa9142a55c3
Code: 8b 15 09 (...)
RSP: 002b:00007fff26278d48 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
RAX: ffffffffffffffda RBX: 0000563c83cb4560 RCX: 00007fa9142a55c3
RDX: 00007fff26278cb0 RSI: 00007fff26278cb0 RDI: 0000000000000005
RBP: 0000000000000005 R08: 0000000000000001 R09: 00007fff26278d5c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000340
R13: 00007fff26278de0 R14: 00007fff26278d96 R15: 0000563c83ca57c0
Modules linked in: btrfs dm_zero dm_snapshot dm_thin_pool (...)
---[ end trace ee2f1b19327d791d ]---
The steps that lead to this crash are the following:
1) We are at transaction N;
2) We have two tasks with a transaction handle attached to transaction N.
Task A and Task B. Task B is doing an fsync;
3) Task B is at btrfs_sync_log(), and has saved fs_info->log_root_tree
into a local variable named 'log_root_tree' at the top of
btrfs_sync_log(). Task B is about to call write_all_supers(), but
before that...
4) Task A calls btrfs_commit_transaction(), and after it sets the
transaction state to TRANS_STATE_COMMIT_START, an error happens before
it waits for the transaction's 'num_writers' counter to reach a value
of 1 (no one else attached to the transaction), so it jumps to the
label "cleanup_transaction";
5) Task A then calls cleanup_transaction(), where it aborts the
transaction, setting BTRFS_FS_STATE_TRANS_ABORTED on fs_info->fs_state,
setting the ->aborted field of the transaction and the handle to an
errno value and also setting BTRFS_FS_STATE_ERROR on fs_info->fs_state.
After that, at cleanup_transaction(), it deletes the transaction from
the list of transactions (fs_info->trans_list), sets the transaction
to the state TRANS_STATE_COMMIT_DOING and then waits for the number
of writers to go down to 1, as it's currently 2 (1 for task A and 1
for task B);
6) The transaction kthread is running and sees that BTRFS_FS_STATE_ERROR
is set in fs_info->fs_state, so it calls btrfs_cleanup_transaction().
There it sees the list fs_info->trans_list is empty, and then proceeds
into calling btrfs_drop_all_logs(), which frees the log root tree with
a call to btrfs_free_log_root_tree();
7) Task B calls write_all_supers() and, shortly after, under the label
'out_wake_log_root', it deferences the pointer stored in
'log_root_tree', which was already freed in the previous step by the
transaction kthread. This results in a use-after-free leading to a
crash.
Fix this by deleting the transaction from the list of transactions at
cleanup_transaction() only after setting the transaction state to
TRANS_STATE_COMMIT_DOING and waiting for all existing tasks that are
attached to the transaction to release their transaction handles.
This makes the transaction kthread wait for all the tasks attached to
the transaction to be done with the transaction before dropping the
log roots and doing other cleanups.
Fixes:
|
||
|
Filipe Manana
|
97f30747b2 |
btrfs: fix metadata extent leak after failure to create subvolume
commit 67addf29004c5be9fa0383c82a364bb59afc7f84 upstream. When creating a subvolume we allocate an extent buffer for its root node after starting a transaction. We setup a root item for the subvolume that points to that extent buffer and then attempt to insert the root item into the root tree - however if that fails, due to ENOMEM for example, we do not free the extent buffer previously allocated and we do not abort the transaction (as at that point we did nothing that can not be undone). This means that we effectively do not return the metadata extent back to the free space cache/tree and we leave a delayed reference for it which causes a metadata extent item to be added to the extent tree, in the next transaction commit, without having backreferences. When this happens 'btrfs check' reports the following: $ btrfs check /dev/sdi Opening filesystem to check... Checking filesystem on /dev/sdi UUID: dce2cb9d-025f-4b05-a4bf-cee0ad3785eb [1/7] checking root items [2/7] checking extents ref mismatch on [30425088 16384] extent item 1, found 0 backref 30425088 root 256 not referenced back 0x564a91c23d70 incorrect global backref count on 30425088 found 1 wanted 0 backpointer mismatch on [30425088 16384] owner ref check failed [30425088 16384] ERROR: errors found in extent allocation tree or chunk allocation [3/7] checking free space cache [4/7] checking fs roots [5/7] checking only csums items (without verifying data) [6/7] checking root refs [7/7] checking quota groups skipped (not enabled on this FS) found 212992 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 124669 file data blocks allocated: 65536 referenced 65536 So fix this by freeing the metadata extent if btrfs_insert_root() returns an error. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@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> |
||
|
Qu Wenruo
|
dba16ca6f3 |
btrfs: handle remount to no compress during compression
commit 1d8ba9e7e785b6625f4d8e978e8a284b144a7077 upstream.
[BUG]
When running btrfs/071 with inode_need_compress() removed from
compress_file_range(), we got the following crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
Workqueue: btrfs-delalloc btrfs_work_helper [btrfs]
RIP: 0010:compress_file_range+0x476/0x7b0 [btrfs]
Call Trace:
? submit_compressed_extents+0x450/0x450 [btrfs]
async_cow_start+0x16/0x40 [btrfs]
btrfs_work_helper+0xf2/0x3e0 [btrfs]
process_one_work+0x278/0x5e0
worker_thread+0x55/0x400
? process_one_work+0x5e0/0x5e0
kthread+0x168/0x190
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x22/0x30
---[ end trace 65faf4eae941fa7d ]---
This is already after the patch "btrfs: inode: fix NULL pointer
dereference if inode doesn't need compression."
[CAUSE]
@pages is firstly created by kcalloc() in compress_file_extent():
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
Then passed to btrfs_compress_pages() to be utilized there:
ret = btrfs_compress_pages(...
pages,
&nr_pages,
...);
btrfs_compress_pages() will initialize each page as output, in
zlib_compress_pages() we have:
pages[nr_pages] = out_page;
nr_pages++;
Normally this is completely fine, but there is a special case which
is in btrfs_compress_pages() itself:
switch (type) {
default:
return -E2BIG;
}
In this case, we didn't modify @pages nor @out_pages, leaving them
untouched, then when we cleanup pages, the we can hit NULL pointer
dereference again:
if (pages) {
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
...
}
Since pages[i] are all initialized to zero, and btrfs_compress_pages()
doesn't change them at all, accessing pages[i]->mapping would lead to
NULL pointer dereference.
This is not possible for current kernel, as we check
inode_need_compress() before doing pages allocation.
But if we're going to remove that inode_need_compress() in
compress_file_extent(), then it's going to be a problem.
[FIX]
When btrfs_compress_pages() hits its default case, modify @out_pages to
0 to prevent such problem from happening.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212331
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@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>
|
||
|
Filipe Manana
|
3b87d0c583 |
btrfs: fix sleep while in non-sleep context during qgroup removal
commit 0bb788300990d3eb5582d3301a720f846c78925c upstream.
While removing a qgroup's sysfs entry we end up taking the kernfs_mutex,
through kobject_del(), while holding the fs_info->qgroup_lock spinlock,
producing the following trace:
[821.843637] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:281
[821.843641] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 28214, name: podman
[821.843644] CPU: 3 PID: 28214 Comm: podman Tainted: G W 5.11.6 #15
[821.843646] Hardware name: Dell Inc. PowerEdge R330/084XW4, BIOS 2.11.0 12/08/2020
[821.843647] Call Trace:
[821.843650] dump_stack+0xa1/0xfb
[821.843656] ___might_sleep+0x144/0x160
[821.843659] mutex_lock+0x17/0x40
[821.843662] kernfs_remove_by_name_ns+0x1f/0x80
[821.843666] sysfs_remove_group+0x7d/0xe0
[821.843668] sysfs_remove_groups+0x28/0x40
[821.843670] kobject_del+0x2a/0x80
[821.843672] btrfs_sysfs_del_one_qgroup+0x2b/0x40 [btrfs]
[821.843685] __del_qgroup_rb+0x12/0x150 [btrfs]
[821.843696] btrfs_remove_qgroup+0x288/0x2a0 [btrfs]
[821.843707] btrfs_ioctl+0x3129/0x36a0 [btrfs]
[821.843717] ? __mod_lruvec_page_state+0x5e/0xb0
[821.843719] ? page_add_new_anon_rmap+0xbc/0x150
[821.843723] ? kfree+0x1b4/0x300
[821.843725] ? mntput_no_expire+0x55/0x330
[821.843728] __x64_sys_ioctl+0x5a/0xa0
[821.843731] do_syscall_64+0x33/0x70
[821.843733] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[821.843736] RIP: 0033:0x4cd3fb
[821.843741] RSP: 002b:000000c000906b20 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
[821.843744] RAX: ffffffffffffffda RBX: 000000c000050000 RCX: 00000000004cd3fb
[821.843745] RDX: 000000c000906b98 RSI: 000000004010942a RDI: 000000000000000f
[821.843747] RBP: 000000c000907cd0 R08: 000000c000622901 R09: 0000000000000000
[821.843748] R10: 000000c000d992c0 R11: 0000000000000206 R12: 000000000000012d
[821.843749] R13: 000000000000012c R14: 0000000000000200 R15: 0000000000000049
Fix this by removing the qgroup sysfs entry while not holding the spinlock,
since the spinlock is only meant for protection of the qgroup rbtree.
Reported-by: Stuart Shelton <srcshelton@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/7A5485BB-0628-419D-A4D3-27B1AF47E25A@gmail.com/
Fixes:
|
||
|
David Sterba
|
2c8d6a9474 |
btrfs: fix slab cache flags for free space tree bitmap
commit 34e49994d0dcdb2d31d4d2908d04f4e9ce57e4d7 upstream.
The free space tree bitmap slab cache is created with SLAB_RED_ZONE but
that's a debugging flag and not always enabled. Also the other slabs are
created with at least SLAB_MEM_SPREAD that we want as well to average
the memory placement cost.
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Fixes:
|
||
|
Filipe Manana
|
38ffe9eaeb |
btrfs: fix race when cloning extent buffer during rewind of an old root
commit dbcc7d57bffc0c8cac9dac11bec548597d59a6a5 upstream.
While resolving backreferences, as part of a logical ino ioctl call or
fiemap, we can end up hitting a BUG_ON() when replaying tree mod log
operations of a root, triggering a stack trace like the following:
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.c:1210!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 PID: 19054 Comm: crawl_335 Tainted: G W 5.11.0-2d11c0084b02-misc-next+ #89
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:__tree_mod_log_rewind+0x3b1/0x3c0
Code: 05 48 8d 74 10 (...)
RSP: 0018:ffffc90001eb70b8 EFLAGS: 00010297
RAX: 0000000000000000 RBX: ffff88812344e400 RCX: ffffffffb28933b6
RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88812344e42c
RBP: ffffc90001eb7108 R08: 1ffff11020b60a20 R09: ffffed1020b60a20
R10: ffff888105b050f9 R11: ffffed1020b60a1f R12: 00000000000000ee
R13: ffff8880195520c0 R14: ffff8881bc958500 R15: ffff88812344e42c
FS: 00007fd1955e8700(0000) GS:ffff8881f5600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efdb7928718 CR3: 000000010103a006 CR4: 0000000000170ee0
Call Trace:
btrfs_search_old_slot+0x265/0x10d0
? lock_acquired+0xbb/0x600
? btrfs_search_slot+0x1090/0x1090
? free_extent_buffer.part.61+0xd7/0x140
? free_extent_buffer+0x13/0x20
resolve_indirect_refs+0x3e9/0xfc0
? lock_downgrade+0x3d0/0x3d0
? __kasan_check_read+0x11/0x20
? add_prelim_ref.part.11+0x150/0x150
? lock_downgrade+0x3d0/0x3d0
? __kasan_check_read+0x11/0x20
? lock_acquired+0xbb/0x600
? __kasan_check_write+0x14/0x20
? do_raw_spin_unlock+0xa8/0x140
? rb_insert_color+0x30/0x360
? prelim_ref_insert+0x12d/0x430
find_parent_nodes+0x5c3/0x1830
? resolve_indirect_refs+0xfc0/0xfc0
? lock_release+0xc8/0x620
? fs_reclaim_acquire+0x67/0xf0
? lock_acquire+0xc7/0x510
? lock_downgrade+0x3d0/0x3d0
? lockdep_hardirqs_on_prepare+0x160/0x210
? lock_release+0xc8/0x620
? fs_reclaim_acquire+0x67/0xf0
? lock_acquire+0xc7/0x510
? poison_range+0x38/0x40
? unpoison_range+0x14/0x40
? trace_hardirqs_on+0x55/0x120
btrfs_find_all_roots_safe+0x142/0x1e0
? find_parent_nodes+0x1830/0x1830
? btrfs_inode_flags_to_xflags+0x50/0x50
iterate_extent_inodes+0x20e/0x580
? tree_backref_for_extent+0x230/0x230
? lock_downgrade+0x3d0/0x3d0
? read_extent_buffer+0xdd/0x110
? lock_downgrade+0x3d0/0x3d0
? __kasan_check_read+0x11/0x20
? lock_acquired+0xbb/0x600
? __kasan_check_write+0x14/0x20
? _raw_spin_unlock+0x22/0x30
? __kasan_check_write+0x14/0x20
iterate_inodes_from_logical+0x129/0x170
? iterate_inodes_from_logical+0x129/0x170
? btrfs_inode_flags_to_xflags+0x50/0x50
? iterate_extent_inodes+0x580/0x580
? __vmalloc_node+0x92/0xb0
? init_data_container+0x34/0xb0
? init_data_container+0x34/0xb0
? kvmalloc_node+0x60/0x80
btrfs_ioctl_logical_to_ino+0x158/0x230
btrfs_ioctl+0x205e/0x4040
? __might_sleep+0x71/0xe0
? btrfs_ioctl_get_supported_features+0x30/0x30
? getrusage+0x4b6/0x9c0
? __kasan_check_read+0x11/0x20
? lock_release+0xc8/0x620
? __might_fault+0x64/0xd0
? lock_acquire+0xc7/0x510
? lock_downgrade+0x3d0/0x3d0
? lockdep_hardirqs_on_prepare+0x210/0x210
? lockdep_hardirqs_on_prepare+0x210/0x210
? __kasan_check_read+0x11/0x20
? do_vfs_ioctl+0xfc/0x9d0
? ioctl_file_clone+0xe0/0xe0
? lock_downgrade+0x3d0/0x3d0
? lockdep_hardirqs_on_prepare+0x210/0x210
? __kasan_check_read+0x11/0x20
? lock_release+0xc8/0x620
? __task_pid_nr_ns+0xd3/0x250
? lock_acquire+0xc7/0x510
? __fget_files+0x160/0x230
? __fget_light+0xf2/0x110
__x64_sys_ioctl+0xc3/0x100
do_syscall_64+0x37/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd1976e2427
Code: 00 00 90 48 8b 05 (...)
RSP: 002b:00007fd1955e5cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd1955e5f40 RCX: 00007fd1976e2427
RDX: 00007fd1955e5f48 RSI: 00000000c038943b RDI: 0000000000000004
RBP: 0000000001000000 R08: 0000000000000000 R09: 00007fd1955e6120
R10: 0000557835366b00 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fd1955e5f48 R14: 00007fd1955e5f40 R15: 00007fd1955e5ef8
Modules linked in:
---[ end trace ec8931a1c36e57be ]---
(gdb) l *(__tree_mod_log_rewind+0x3b1)
0xffffffff81893521 is in __tree_mod_log_rewind (fs/btrfs/ctree.c:1210).
1205 * the modification. as we're going backwards, we do the
1206 * opposite of each operation here.
1207 */
1208 switch (tm->op) {
1209 case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
1210 BUG_ON(tm->slot < n);
1211 fallthrough;
1212 case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
1213 case MOD_LOG_KEY_REMOVE:
1214 btrfs_set_node_key(eb, &tm->key, tm->slot);
Here's what happens to hit that BUG_ON():
1) We have one tree mod log user (through fiemap or the logical ino ioctl),
with a sequence number of 1, so we have fs_info->tree_mod_seq == 1;
2) Another task is at ctree.c:balance_level() and we have eb X currently as
the root of the tree, and we promote its single child, eb Y, as the new
root.
Then, at ctree.c:balance_level(), we call:
tree_mod_log_insert_root(eb X, eb Y, 1);
3) At tree_mod_log_insert_root() we create tree mod log elements for each
slot of eb X, of operation type MOD_LOG_KEY_REMOVE_WHILE_FREEING each
with a ->logical pointing to ebX->start. These are placed in an array
named tm_list.
Lets assume there are N elements (N pointers in eb X);
4) Then, still at tree_mod_log_insert_root(), we create a tree mod log
element of operation type MOD_LOG_ROOT_REPLACE, ->logical set to
ebY->start, ->old_root.logical set to ebX->start, ->old_root.level set
to the level of eb X and ->generation set to the generation of eb X;
5) Then tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
tm_list as argument. After that, tree_mod_log_free_eb() calls
__tree_mod_log_insert() for each member of tm_list in reverse order,
from highest slot in eb X, slot N - 1, to slot 0 of eb X;
6) __tree_mod_log_insert() sets the sequence number of each given tree mod
log operation - it increments fs_info->tree_mod_seq and sets
fs_info->tree_mod_seq as the sequence number of the given tree mod log
operation.
This means that for the tm_list created at tree_mod_log_insert_root(),
the element corresponding to slot 0 of eb X has the highest sequence
number (1 + N), and the element corresponding to the last slot has the
lowest sequence number (2);
7) Then, after inserting tm_list's elements into the tree mod log rbtree,
the MOD_LOG_ROOT_REPLACE element is inserted, which gets the highest
sequence number, which is N + 2;
8) Back to ctree.c:balance_level(), we free eb X by calling
btrfs_free_tree_block() on it. Because eb X was created in the current
transaction, has no other references and writeback did not happen for
it, we add it back to the free space cache/tree;
9) Later some other task T allocates the metadata extent from eb X, since
it is marked as free space in the space cache/tree, and uses it as a
node for some other btree;
10) The tree mod log user task calls btrfs_search_old_slot(), which calls
get_old_root(), and finally that calls __tree_mod_log_oldest_root()
with time_seq == 1 and eb_root == eb Y;
11) First iteration of the while loop finds the tree mod log element with
sequence number N + 2, for the logical address of eb Y and of type
MOD_LOG_ROOT_REPLACE;
12) Because the operation type is MOD_LOG_ROOT_REPLACE, we don't break out
of the loop, and set root_logical to point to tm->old_root.logical
which corresponds to the logical address of eb X;
13) On the next iteration of the while loop, the call to
tree_mod_log_search_oldest() returns the smallest tree mod log element
for the logical address of eb X, which has a sequence number of 2, an
operation type of MOD_LOG_KEY_REMOVE_WHILE_FREEING and corresponds to
the old slot N - 1 of eb X (eb X had N items in it before being freed);
14) We then break out of the while loop and return the tree mod log operation
of type MOD_LOG_ROOT_REPLACE (eb Y), and not the one for slot N - 1 of
eb X, to get_old_root();
15) At get_old_root(), we process the MOD_LOG_ROOT_REPLACE operation
and set "logical" to the logical address of eb X, which was the old
root. We then call tree_mod_log_search() passing it the logical
address of eb X and time_seq == 1;
16) Then before calling tree_mod_log_search(), task T adds a key to eb X,
which results in adding a tree mod log operation of type
MOD_LOG_KEY_ADD to the tree mod log - this is done at
ctree.c:insert_ptr() - but after adding the tree mod log operation
and before updating the number of items in eb X from 0 to 1...
17) The task at get_old_root() calls tree_mod_log_search() and gets the
tree mod log operation of type MOD_LOG_KEY_ADD just added by task T.
Then it enters the following if branch:
if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
(...)
} (...)
Calls read_tree_block() for eb X, which gets a reference on eb X but
does not lock it - task T has it locked.
Then it clones eb X while it has nritems set to 0 in its header, before
task T sets nritems to 1 in eb X's header. From hereupon we use the
clone of eb X which no other task has access to;
18) Then we call __tree_mod_log_rewind(), passing it the MOD_LOG_KEY_ADD
mod log operation we just got from tree_mod_log_search() in the
previous step and the cloned version of eb X;
19) At __tree_mod_log_rewind(), we set the local variable "n" to the number
of items set in eb X's clone, which is 0. Then we enter the while loop,
and in its first iteration we process the MOD_LOG_KEY_ADD operation,
which just decrements "n" from 0 to (u32)-1, since "n" is declared with
a type of u32. At the end of this iteration we call rb_next() to find the
next tree mod log operation for eb X, that gives us the mod log operation
of type MOD_LOG_KEY_REMOVE_WHILE_FREEING, for slot 0, with a sequence
number of N + 1 (steps 3 to 6);
20) Then we go back to the top of the while loop and trigger the following
BUG_ON():
(...)
switch (tm->op) {
case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
BUG_ON(tm->slot < n);
fallthrough;
(...)
Because "n" has a value of (u32)-1 (4294967295) and tm->slot is 0.
Fix this by taking a read lock on the extent buffer before cloning it at
ctree.c:get_old_root(). This should be done regardless of the extent
buffer having been freed and reused, as a concurrent task might be
modifying it (while holding a write lock on it).
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210227155037.GN28049@hungrycats.org/
Fixes:
|
||
|
Nikolay Borisov
|
bf6dd437c3 |
btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
commit 4d14c5cde5c268a2bc26addecf09489cb953ef64 upstream
Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:
* ae5e070eaca9 ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")
*
|
||
|
Nikolay Borisov
|
cf9317ceb5 |
btrfs: export and rename qgroup_reserve_meta
commit 80e9baed722c853056e0c5374f51524593cb1031 upstream Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@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> |
||
|
Filipe Manana
|
ae971992e9 |
btrfs: fix warning when creating a directory with smack enabled
commit fd57a98d6f0c98fa295813087f13afb26c224e73 upstream. When we have smack enabled, during the creation of a directory smack may attempt to add a "smack transmute" xattr on the inode, which results in the following warning and trace: WARNING: CPU: 3 PID: 2548 at fs/btrfs/transaction.c:537 start_transaction+0x489/0x4f0 Modules linked in: nft_objref nf_conntrack_netbios_ns (...) CPU: 3 PID: 2548 Comm: mkdir Not tainted 5.9.0-rc2smack+ #81 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:start_transaction+0x489/0x4f0 Code: e9 be fc ff ff (...) RSP: 0018:ffffc90001887d10 EFLAGS: 00010202 RAX: ffff88816f1e0000 RBX: 0000000000000201 RCX: 0000000000000003 RDX: 0000000000000201 RSI: 0000000000000002 RDI: ffff888177849000 RBP: ffff888177849000 R08: 0000000000000001 R09: 0000000000000004 R10: ffffffff825e8f7a R11: 0000000000000003 R12: ffffffffffffffe2 R13: 0000000000000000 R14: ffff88803d884270 R15: ffff8881680d8000 FS: 00007f67317b8440(0000) GS:ffff88817bcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f67247a22a8 CR3: 000000004bfbc002 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? slab_free_freelist_hook+0xea/0x1b0 ? trace_hardirqs_on+0x1c/0xe0 btrfs_setxattr_trans+0x3c/0xf0 __vfs_setxattr+0x63/0x80 smack_d_instantiate+0x2d3/0x360 security_d_instantiate+0x29/0x40 d_instantiate_new+0x38/0x90 btrfs_mkdir+0x1cf/0x1e0 vfs_mkdir+0x14f/0x200 do_mkdirat+0x6d/0x110 do_syscall_64+0x2d/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f673196ae6b Code: 8b 05 11 (...) RSP: 002b:00007ffc3c679b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00000000000001ff RCX: 00007f673196ae6b RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00007ffc3c67a30d RBP: 00007ffc3c67a30d R08: 00000000000001ff R09: 0000000000000000 R10: 000055d3e39fe930 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc3c679cd8 R14: 00007ffc3c67a30d R15: 00007ffc3c679ce0 irq event stamp: 11029 hardirqs last enabled at (11037): [<ffffffff81153fe6>] console_unlock+0x486/0x670 hardirqs last disabled at (11044): [<ffffffff81153c01>] console_unlock+0xa1/0x670 softirqs last enabled at (8864): [<ffffffff81e0102f>] asm_call_on_stack+0xf/0x20 softirqs last disabled at (8851): [<ffffffff81e0102f>] asm_call_on_stack+0xf/0x20 This happens because at btrfs_mkdir() we call d_instantiate_new() while holding a transaction handle, which results in the following call chain: btrfs_mkdir() trans = btrfs_start_transaction(root, 5); d_instantiate_new() smack_d_instantiate() __vfs_setxattr() btrfs_setxattr_trans() btrfs_start_transaction() start_transaction() WARN_ON() --> a tansaction start has TRANS_EXTWRITERS set in its type h->orig_rsv = h->block_rsv h->block_rsv = NULL btrfs_end_transaction(trans) Besides the warning triggered at start_transaction, we set the handle's block_rsv to NULL which may cause some surprises later on. So fix this by making btrfs_setxattr_trans() not start a transaction when we already have a handle on one, stored in current->journal_info, and use that handle. We are good to use the handle because at btrfs_mkdir() we did reserve space for the xattr and the inode item. Reported-by: Casey Schaufler <casey@schaufler-ca.com> CC: stable@vger.kernel.org # 5.4+ Acked-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com> Link: https://lore.kernel.org/linux-btrfs/434d856f-bd7b-4889-a6ec-e81aaebfa735@schaufler-ca.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> |
||
|
Nikolay Borisov
|
e6ba61aaff |
btrfs: unlock extents in btrfs_zero_range in case of quota reservation errors
commit 4f6a49de64fd1b1dba5229c02047376da7cf24fd upstream.
If btrfs_qgroup_reserve_data returns an error (i.e quota limit reached)
the handling logic directly goes to the 'out' label without first
unlocking the extent range between lockstart, lockend. This results in
deadlocks as other processes try to lock the same extent.
Fixes:
|
||
|
Nikolay Borisov
|
37ffce9668 |
btrfs: free correct amount of space in btrfs_delayed_inode_reserve_metadata
commit 0f9c03d824f6f522d3bc43629635c9765546ebc5 upstream. Following commit |
||
|
Dan Carpenter
|
a64ad80223 |
btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl
commit 5011c5a663b9c6d6aff3d394f11049b371199627 upstream.
The problem is we're copying "inherit" from user space but we don't
necessarily know that we're copying enough data for a 64 byte
struct. Then the next problem is that 'inherit' has a variable size
array at the end, and we have to verify that array is the size we
expected.
Fixes:
|
||
|
Nikolay Borisov
|
e82407d249 |
btrfs: fix race between extent freeing/allocation when using bitmaps
commit 3c17916510428dbccdf657de050c34e208347089 upstream.
During allocation the allocator will try to allocate an extent using
cluster policy. Once the current cluster is exhausted it will remove the
entry under btrfs_free_cluster::lock and subsequently acquire
btrfs_free_space_ctl::tree_lock to dispose of the already-deleted entry
and adjust btrfs_free_space_ctl::total_bitmap. This poses a problem
because there exists a race condition between removing the entry under
one lock and doing the necessary accounting holding a different lock
since extent freeing only uses the 2nd lock. This can result in the
following situation:
T1: T2:
btrfs_alloc_from_cluster insert_into_bitmap <holds tree_lock>
if (entry->bytes == 0) if (block_group && !list_empty(&block_group->cluster_list)) {
rb_erase(entry)
spin_unlock(&cluster->lock);
(total_bitmaps is still 4) spin_lock(&cluster->lock);
<doesn't find entry in cluster->root>
spin_lock(&ctl->tree_lock); <goes to new_bitmap label, adds
<blocked since T2 holds tree_lock> <a new entry and calls add_new_bitmap>
recalculate_thresholds <crashes,
due to total_bitmaps
becoming 5 and triggering
an ASSERT>
To fix this ensure that once depleted, the cluster entry is deleted when
both cluster lock and tree locks are held in the allocator (T1), this
ensures that even if there is a race with a concurrent
insert_into_bitmap call it will correctly find the entry in the cluster
and add the new space to it.
CC: <stable@vger.kernel.org> # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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||
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Filipe Manana
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1559d94fec |
btrfs: fix stale data exposure after cloning a hole with NO_HOLES enabled
commit 3660d0bcdb82807d434da9d2e57d88b37331182d upstream.
When using the NO_HOLES feature, if we clone a file range that spans only
a hole into a range that is at or beyond the current i_size of the
destination file, we end up not setting the full sync runtime flag on the
inode. As a result, if we then fsync the destination file and have a power
failure, after log replay we can end up exposing stale data instead of
having a hole for that range.
The conditions for this to happen are the following:
1) We have a file with a size of, for example, 1280K;
2) There is a written (non-prealloc) extent for the file range from 1024K
to 1280K with a length of 256K;
3) This particular file extent layout is durably persisted, so that the
existing superblock persisted on disk points to a subvolume root where
the file has that exact file extent layout and state;
4) The file is truncated to a smaller size, to an offset lower than the
start offset of its last extent, for example to 800K. The truncate sets
the full sync runtime flag on the inode;
6) Fsync the file to log it and clear the full sync runtime flag;
7) Clone a region that covers only a hole (implicit hole due to NO_HOLES)
into the file with a destination offset that starts at or beyond the
256K file extent item we had - for example to offset 1024K;
8) Since the clone operation does not find extents in the source range,
we end up in the if branch at the bottom of btrfs_clone() where we
punch a hole for the file range starting at offset 1024K by calling
btrfs_replace_file_extents(). There we end up not setting the full
sync flag on the inode, because we don't know we are being called in
a clone context (and not fallocate's punch hole operation), and
neither do we create an extent map to represent a hole because the
requested range is beyond eof;
9) A further fsync to the file will be a fast fsync, since the clone
operation did not set the full sync flag, and therefore it relies on
modified extent maps to correctly log the file layout. But since
it does not find any extent map marking the range from 1024K (the
previous eof) to the new eof, it does not log a file extent item
for that range representing the hole;
10) After a power failure no hole for the range starting at 1024K is
punched and we end up exposing stale data from the old 256K extent.
Turning this into exact steps:
$ mkfs.btrfs -f -O no-holes /dev/sdi
$ mount /dev/sdi /mnt
# Create our test file with 3 extents of 256K and a 256K hole at offset
# 256K. The file has a size of 1280K.
$ xfs_io -f -s \
-c "pwrite -S 0xab -b 256K 0 256K" \
-c "pwrite -S 0xcd -b 256K 512K 256K" \
-c "pwrite -S 0xef -b 256K 768K 256K" \
-c "pwrite -S 0x73 -b 256K 1024K 256K" \
/mnt/sdi/foobar
# Make sure it's durably persisted. We want the last committed super
# block to point to this particular file extent layout.
sync
# Now truncate our file to a smaller size, falling within a position of
# the second extent. This sets the full sync runtime flag on the inode.
# Then fsync the file to log it and clear the full sync flag from the
# inode. The third extent is no longer part of the file and therefore
# it is not logged.
$ xfs_io -c "truncate 800K" -c "fsync" /mnt/foobar
# Now do a clone operation that only clones the hole and sets back the
# file size to match the size it had before the truncate operation
# (1280K).
$ xfs_io \
-c "reflink /mnt/foobar 256K 1024K 256K" \
-c "fsync" \
/mnt/foobar
# File data before power failure:
$ od -A d -t x1 /mnt/foobar
0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab
*
0262144 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
0524288 cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd
*
0786432 ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef
*
0819200 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
1310720
<power fail>
# Mount the fs again to replay the log tree.
$ mount /dev/sdi /mnt
# File data after power failure:
$ od -A d -t x1 /mnt/foobar
0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab
*
0262144 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
0524288 cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd
*
0786432 ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef
*
0819200 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
1048576 73 73 73 73 73 73 73 73 73 73 73 73 73 73 73 73
*
1310720
The range from 1024K to 1280K should correspond to a hole but instead it
points to stale data, to the 256K extent that should not exist after the
truncate operation.
The issue does not exists when not using NO_HOLES, because for that case
we use file extent items to represent holes, these are found and copied
during the loop that iterates over extents at btrfs_clone(), and that
causes btrfs_replace_file_extents() to be called with a non-NULL
extent_info argument and therefore set the full sync runtime flag on the
inode.
So fix this by making the code that deals with a trailing hole during
cloning, at btrfs_clone(), to set the full sync flag on the inode, if the
range starts at or beyond the current i_size.
A test case for fstests will follow soon.
Backporting notes: for kernel 5.4 the change goes to ioctl.c into
btrfs_clone before the last call to btrfs_punch_hole_range.
CC: stable@vger.kernel.org # 5.4+
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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