9567 Commits

Author SHA1 Message Date
Sasha Levin
58de7a95f0 btrfs: replace strncpy() with strscpy()
[ Upstream commit 63d5429f68a3d4c4aa27e65a05196c17f86c41d6 ]

Using strncpy() on NUL-terminated strings are deprecated.  To avoid
possible forming of non-terminated string strscpy() should be used.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:40 +01:00
Boris Burkov
0061ab5153 btrfs: fix resolving backrefs for inline extent followed by prealloc
commit 560840afc3e63bbe5d9c5ef6b2ecf8f3589adff6 upstream.

If a file consists of an inline extent followed by a regular or prealloc
extent, then a legitimate attempt to resolve a logical address in the
non-inline region will result in add_all_parents reading the invalid
offset field of the inline extent. If the inline extent item is placed
in the leaf eb s.t. it is the first item, attempting to access the
offset field will not only be meaningless, it will go past the end of
the eb and cause this panic:

  [17.626048] BTRFS warning (device dm-2): bad eb member end: ptr 0x3fd4 start 30834688 member offset 16377 size 8
  [17.631693] general protection fault, probably for non-canonical address 0x5088000000000: 0000 [#1] SMP PTI
  [17.635041] CPU: 2 PID: 1267 Comm: btrfs Not tainted 5.12.0-07246-g75175d5adc74-dirty #199
  [17.637969] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  [17.641995] RIP: 0010:btrfs_get_64+0xe7/0x110
  [17.649890] RSP: 0018:ffffc90001f73a08 EFLAGS: 00010202
  [17.651652] RAX: 0000000000000001 RBX: ffff88810c42d000 RCX: 0000000000000000
  [17.653921] RDX: 0005088000000000 RSI: ffffc90001f73a0f RDI: 0000000000000001
  [17.656174] RBP: 0000000000000ff9 R08: 0000000000000007 R09: c0000000fffeffff
  [17.658441] R10: ffffc90001f73790 R11: ffffc90001f73788 R12: ffff888106afe918
  [17.661070] R13: 0000000000003fd4 R14: 0000000000003f6f R15: cdcdcdcdcdcdcdcd
  [17.663617] FS:  00007f64e7627d80(0000) GS:ffff888237c80000(0000) knlGS:0000000000000000
  [17.666525] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [17.668664] CR2: 000055d4a39152e8 CR3: 000000010c596002 CR4: 0000000000770ee0
  [17.671253] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [17.673634] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [17.676034] PKRU: 55555554
  [17.677004] Call Trace:
  [17.677877]  add_all_parents+0x276/0x480
  [17.679325]  find_parent_nodes+0xfae/0x1590
  [17.680771]  btrfs_find_all_leafs+0x5e/0xa0
  [17.682217]  iterate_extent_inodes+0xce/0x260
  [17.683809]  ? btrfs_inode_flags_to_xflags+0x50/0x50
  [17.685597]  ? iterate_inodes_from_logical+0xa1/0xd0
  [17.687404]  iterate_inodes_from_logical+0xa1/0xd0
  [17.689121]  ? btrfs_inode_flags_to_xflags+0x50/0x50
  [17.691010]  btrfs_ioctl_logical_to_ino+0x131/0x190
  [17.692946]  btrfs_ioctl+0x104a/0x2f60
  [17.694384]  ? selinux_file_ioctl+0x182/0x220
  [17.695995]  ? __x64_sys_ioctl+0x84/0xc0
  [17.697394]  __x64_sys_ioctl+0x84/0xc0
  [17.698697]  do_syscall_64+0x33/0x40
  [17.700017]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [17.701753] RIP: 0033:0x7f64e72761b7
  [17.709355] RSP: 002b:00007ffefb067f58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [17.712088] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f64e72761b7
  [17.714667] RDX: 00007ffefb067fb0 RSI: 00000000c0389424 RDI: 0000000000000003
  [17.717386] RBP: 00007ffefb06d188 R08: 000055d4a390d2b0 R09: 00007f64e7340a60
  [17.719938] R10: 0000000000000231 R11: 0000000000000246 R12: 0000000000000001
  [17.722383] R13: 0000000000000000 R14: 00000000c0389424 R15: 000055d4a38fd2a0
  [17.724839] Modules linked in:

Fix the bug by detecting the inline extent item in add_all_parents and
skipping to the next extent item.

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:30 +01:00
Filipe Manana
688a45aff2 btrfs: send: avoid unaligned encoded writes when attempting to clone range
[ Upstream commit a11452a3709e217492798cf3686ac2cc8eb3fb51 ]

When trying to see if we can clone a file range, there are cases where we
end up sending two write operations in case the inode from the source root
has an i_size that is not sector size aligned and the length from the
current offset to its i_size is less than the remaining length we are
trying to clone.

Issuing two write operations when we could instead issue a single write
operation is not incorrect. However it is not optimal, specially if the
extents are compressed and the flag BTRFS_SEND_FLAG_COMPRESSED was passed
to the send ioctl. In that case we can end up sending an encoded write
with an offset that is not sector size aligned, which makes the receiver
fallback to decompressing the data and writing it using regular buffered
IO (so re-compressing the data in case the fs is mounted with compression
enabled), because encoded writes fail with -EINVAL when an offset is not
sector size aligned.

The following example, which triggered a bug in the receiver code for the
fallback logic of decompressing + regular buffer IO and is fixed by the
patchset referred in a Link at the bottom of this changelog, is an example
where we have the non-optimal behaviour due to an unaligned encoded write:

   $ cat test.sh
   #!/bin/bash

   DEV=/dev/sdj
   MNT=/mnt/sdj

   mkfs.btrfs -f $DEV > /dev/null
   mount -o compress $DEV $MNT

   # File foo has a size of 33K, not aligned to the sector size.
   xfs_io -f -c "pwrite -S 0xab 0 33K" $MNT/foo

   xfs_io -f -c "pwrite -S 0xcd 0 64K" $MNT/bar

   # Now clone the first 32K of file bar into foo at offset 0.
   xfs_io -c "reflink $MNT/bar 0 0 32K" $MNT/foo

   # Snapshot the default subvolume and create a full send stream (v2).
   btrfs subvolume snapshot -r $MNT $MNT/snap

   btrfs send --compressed-data -f /tmp/test.send $MNT/snap

   echo -e "\nFile bar in the original filesystem:"
   od -A d -t x1 $MNT/snap/bar

   umount $MNT
   mkfs.btrfs -f $DEV > /dev/null
   mount $DEV $MNT

   echo -e "\nReceiving stream in a new filesystem..."
   btrfs receive -f /tmp/test.send $MNT

   echo -e "\nFile bar in the new filesystem:"
   od -A d -t x1 $MNT/snap/bar

   umount $MNT

Before this patch, the send stream included one regular write and one
encoded write for file 'bar', with the later being not sector size aligned
and causing the receiver to fallback to decompression + buffered writes.
The output of the btrfs receive command in verbose mode (-vvv):

   (...)
   mkfile o258-7-0
   rename o258-7-0 -> bar
   utimes
   clone bar - source=foo source offset=0 offset=0 length=32768
   write bar - offset=32768 length=1024
   encoded_write bar - offset=33792, len=4096, unencoded_offset=33792, unencoded_file_len=31744, unencoded_len=65536, compression=1, encryption=0
   encoded_write bar - falling back to decompress and write due to errno 22 ("Invalid argument")
   (...)

This patch avoids the regular write followed by an unaligned encoded write
so that we end up sending a single encoded write that is aligned. So after
this patch the stream content is (output of btrfs receive -vvv):

   (...)
   mkfile o258-7-0
   rename o258-7-0 -> bar
   utimes
   clone bar - source=foo source offset=0 offset=0 length=32768
   encoded_write bar - offset=32768, len=4096, unencoded_offset=32768, unencoded_file_len=32768, unencoded_len=65536, compression=1, encryption=0
   (...)

So we get more optimal behaviour and avoid the silent data loss bug in
versions of btrfs-progs affected by the bug referred by the Link tag
below (btrfs-progs v5.19, v5.19.1, v6.0 and v6.0.1).

Link: https://lore.kernel.org/linux-btrfs/cover.1668529099.git.fdmanana@suse.com/
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:53 +01:00
ChenXiaoSong
01d7c41eac btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()
[ Upstream commit f7e942b5bb35d8e3af54053d19a6bf04143a3955 ]

Syzkaller reported BUG as follows:

  BUG: sleeping function called from invalid context at
       include/linux/sched/mm.h:274
  Call Trace:
   <TASK>
   dump_stack_lvl+0xcd/0x134
   __might_resched.cold+0x222/0x26b
   kmem_cache_alloc+0x2e7/0x3c0
   update_qgroup_limit_item+0xe1/0x390
   btrfs_qgroup_inherit+0x147b/0x1ee0
   create_subvol+0x4eb/0x1710
   btrfs_mksubvol+0xfe5/0x13f0
   __btrfs_ioctl_snap_create+0x2b0/0x430
   btrfs_ioctl_snap_create_v2+0x25a/0x520
   btrfs_ioctl+0x2a1c/0x5ce0
   __x64_sys_ioctl+0x193/0x200
   do_syscall_64+0x35/0x80

Fix this by calling qgroup_dirty() on @dstqgroup, and update limit item in
btrfs_run_qgroups() later outside of the spinlock context.

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:23:54 +01:00
Nikolay Borisov
1faf21bdd1 btrfs: move QUOTA_ENABLED check to rescan_should_stop from btrfs_qgroup_rescan_worker
[ Upstream commit db5df254120004471e1c957957ab2f1e612dcbd6 ]

Instead of having 2 places that short circuit the qgroup leaf scan have
everything in the qgroup_rescan_leaf function. In addition to that, also
ensure that the inconsistent qgroup flag is set when rescan_should_stop
returns true. This both retains the old behavior when -EINTR was set in
the body of the loop and at the same time also extends this behavior
when scanning is interrupted due to remount or unmount operations.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: f7e942b5bb35 ("btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:23:54 +01:00
Anand Jain
7b020665d4 btrfs: free btrfs_path before copying inodes to userspace
[ Upstream commit 418ffb9e3cf6c4e2574d3a732b724916684bd133 ]

btrfs_ioctl_logical_to_ino() frees the search path after the userspace
copy from the temp buffer @inodes. Which potentially can lead to a lock
splat.

Fix this by freeing the path before we copy @inodes to userspace.

CC: stable@vger.kernel.org # 4.19+
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: Sasha Levin <sashal@kernel.org>
2022-12-08 11:23:53 +01:00
David Sterba
d5b7a34379 btrfs: sink iterator parameter to btrfs_ioctl_logical_to_ino
[ Upstream commit e3059ec06b9f1a96826cc2bb6ed131aac0942446 ]

There's only one function we pass to iterate_inodes_from_logical as
iterator, so we can drop the indirection and call it directly, after
moving the function to backref.c

Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 418ffb9e3cf6 ("btrfs: free btrfs_path before copying inodes to userspace")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:23:53 +01:00
Zhen Lei
c86c1a7037 btrfs: sysfs: normalize the error handling branch in btrfs_init_sysfs()
commit ffdbb44f2f23f963b8f5672e35c3a26088177a62 upstream.

Although kset_unregister() can eventually remove all attribute files,
explicitly rolling back with the matching function makes the code logic
look clearer.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.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>
2022-12-02 17:40:06 +01:00
Anand Jain
1581830c0e btrfs: free btrfs_path before copying subvol info to userspace
commit 013c1c5585ebcfb19c88efe79063d0463b1b6159 upstream.

btrfs_ioctl_get_subvol_info() frees the search path after the userspace
copy from the temp buffer @subvol_info. This can lead to a lock splat
warning.

Fix this by freeing the path before we copy it to userspace.

CC: stable@vger.kernel.org # 4.19+
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>
2022-12-02 17:40:06 +01:00
Anand Jain
0bdb8f7ef8 btrfs: free btrfs_path before copying fspath to userspace
commit 8cf96b409d9b3946ece58ced13f92d0f775b0442 upstream.

btrfs_ioctl_ino_to_path() frees the search path after the userspace copy
from the temp buffer @ipath->fspath. Which potentially can lead to a lock
splat warning.

Fix this by freeing the path before we copy it to userspace.

CC: stable@vger.kernel.org # 4.19+
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>
2022-12-02 17:40:06 +01:00
Josef Bacik
24a37ba2cb btrfs: free btrfs_path before copying root refs to userspace
commit b740d806166979488e798e41743aaec051f2443f upstream.

Syzbot reported the following lockdep splat

======================================================
WARNING: possible circular locking dependency detected
6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted
------------------------------------------------------
syz-executor307/3029 is trying to acquire lock:
ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576

but task is already holding lock:
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (btrfs-root-00){++++}-{3:3}:
       down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624
       __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
       btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
       btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279
       btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637
       btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944
       btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132
       commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459
       btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343
       flush_space+0x66c/0x738 fs/btrfs/space-info.c:786
       btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059
       process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
       worker_thread+0x340/0x610 kernel/workqueue.c:2436
       kthread+0x12c/0x158 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

-> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline]
       start_transaction+0x248/0x944 fs/btrfs/transaction.c:752
       btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781
       btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651
       btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0x804/0x11c4 fs/namei.c:3688
       do_filp_open+0xdc/0x1b8 fs/namei.c:3718
       do_sys_openat2+0xb8/0x22c fs/open.c:1313
       do_sys_open fs/open.c:1329 [inline]
       __do_sys_openat fs/open.c:1345 [inline]
       __se_sys_openat fs/open.c:1340 [inline]
       __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #1 (sb_internal#2){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1826 [inline]
       sb_start_intwrite include/linux/fs.h:1948 [inline]
       start_transaction+0x360/0x944 fs/btrfs/transaction.c:683
       btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795
       btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103
       btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145
       inode_update_time fs/inode.c:1872 [inline]
       touch_atime+0x1f0/0x4a8 fs/inode.c:1945
       file_accessed include/linux/fs.h:2516 [inline]
       btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407
       call_mmap include/linux/fs.h:2192 [inline]
       mmap_region+0x7fc/0xc14 mm/mmap.c:1752
       do_mmap+0x644/0x97c mm/mmap.c:1540
       vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552
       ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3829 [inline]
       __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
       lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
       __might_fault+0x7c/0xb4 mm/memory.c:5577
       _copy_to_user include/linux/uaccess.h:134 [inline]
       copy_to_user include/linux/uaccess.h:160 [inline]
       btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
       btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(btrfs-root-00);
                               lock(&fs_info->reloc_mutex);
                               lock(btrfs-root-00);
  lock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor307/3029:
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

stack backtrace:
CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053
 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3829 [inline]
 __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
 __might_fault+0x7c/0xb4 mm/memory.c:5577
 _copy_to_user include/linux/uaccess.h:134 [inline]
 copy_to_user include/linux/uaccess.h:160 [inline]
 btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

We do generally the right thing here, copying the references into a
temporary buffer, however we are still holding the path when we do
copy_to_user from the temporary buffer.  Fix this by freeing the path
before we copy to user space.

Reported-by: syzbot+4ef9e52e464c6ff47d9d@syzkaller.appspotmail.com
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Anand Jain <anand.jain@oracle.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>
2022-12-02 17:40:06 +01:00
Filipe Manana
ce75e90859 btrfs: remove pointless and double ulist frees in error paths of qgroup tests
[ Upstream commit d0ea17aec12ea0f7b9d2ed727d8ef8169d1e7699 ]

Several places in the qgroup self tests follow the pattern of freeing the
ulist pointer they passed to btrfs_find_all_roots() if the call to that
function returned an error. That is pointless because that function always
frees the ulist in case it returns an error.

Also In some places like at test_multiple_refs(), after a call to
btrfs_qgroup_account_extent() we also leave "old_roots" and "new_roots"
pointing to ulists that were freed, because btrfs_qgroup_account_extent()
has freed those ulists, and if after that the next call to
btrfs_find_all_roots() fails, we call ulist_free() on the "old_roots"
ulist again, resulting in a double free.

So remove those calls to reduce the code size and avoid double ulist
free in case of an error.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25 17:45:40 +01:00
Zhang Xiaoxu
9c0accfa5a btrfs: selftests: fix wrong error check in btrfs_free_dummy_root()
commit 9b2f20344d450137d015b380ff0c2e2a6a170135 upstream.

The btrfs_alloc_dummy_root() uses ERR_PTR as the error return value
rather than NULL, if error happened, there will be a NULL pointer
dereference:

  BUG: KASAN: null-ptr-deref in btrfs_free_dummy_root+0x21/0x50 [btrfs]
  Read of size 8 at addr 000000000000002c by task insmod/258926

  CPU: 2 PID: 258926 Comm: insmod Tainted: G        W          6.1.0-rc2+ #5
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x44
   kasan_report+0xb7/0x140
   kasan_check_range+0x145/0x1a0
   btrfs_free_dummy_root+0x21/0x50 [btrfs]
   btrfs_test_free_space_cache+0x1a8c/0x1add [btrfs]
   btrfs_run_sanity_tests+0x65/0x80 [btrfs]
   init_btrfs_fs+0xec/0x154 [btrfs]
   do_one_initcall+0x87/0x2a0
   do_init_module+0xdf/0x320
   load_module+0x3006/0x3390
   __do_sys_finit_module+0x113/0x1b0
   do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: aaedb55bc08f ("Btrfs: add tests for btrfs_get_extent")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.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>
2022-11-16 09:57:17 +01:00
David Sterba
06de93a47c btrfs: fix type of parameter generation in btrfs_get_dentry
commit 2398091f9c2c8e0040f4f9928666787a3e8108a7 upstream.

The type of parameter generation has been u32 since the beginning,
however all callers pass a u64 generation, so unify the types to prevent
potential loss.

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 18:14:25 +01:00
Filipe Manana
0a0dead4ad btrfs: fix ulist leaks in error paths of qgroup self tests
[ Upstream commit d37de92b38932d40e4a251e876cc388f9aee5f42 ]

In the test_no_shared_qgroup() and test_multiple_refs() qgroup self tests,
if we fail to add the tree ref, remove the extent item or remove the
extent ref, we are returning from the test function without freeing the
"old_roots" ulist that was allocated by the previous calls to
btrfs_find_all_roots(). Fix that by calling ulist_free() before returning.

Fixes: 442244c96332 ("btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 18:14:19 +01:00
Filipe Manana
61e0612811 btrfs: fix inode list leak during backref walking at find_parent_nodes()
[ Upstream commit 92876eec382a0f19f33d09d2c939e9ca49038ae5 ]

During backref walking, at find_parent_nodes(), if we are dealing with a
data extent and we get an error while resolving the indirect backrefs, at
resolve_indirect_refs(), or in the while loop that iterates over the refs
in the direct refs rbtree, we end up leaking the inode lists attached to
the direct refs we have in the direct refs rbtree that were not yet added
to the refs ulist passed as argument to find_parent_nodes(). Since they
were not yet added to the refs ulist and prelim_release() does not free
the lists, on error the caller can only free the lists attached to the
refs that were added to the refs ulist, all the remaining refs get their
inode lists never freed, therefore leaking their memory.

Fix this by having prelim_release() always free any attached inode list
to each ref found in the rbtree, and have find_parent_nodes() set the
ref's inode list to NULL once it transfers ownership of the inode list
to a ref added to the refs ulist passed to find_parent_nodes().

Fixes: 86d5f9944252 ("btrfs: convert prelimary reference tracking to use rbtrees")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 18:14:19 +01:00
Filipe Manana
a52e24c7fc btrfs: fix inode list leak during backref walking at resolve_indirect_refs()
[ Upstream commit 5614dc3a47e3310fbc77ea3b67eaadd1c6417bf1 ]

During backref walking, at resolve_indirect_refs(), if we get an error
we jump to the 'out' label and call ulist_free() on the 'parents' ulist,
which frees all the elements in the ulist - however that does not free
any inode lists that may be attached to elements, through the 'aux' field
of a ulist node, so we end up leaking lists if we have any attached to
the unodes.

Fix this by calling free_leaf_list() instead of ulist_free() when we exit
from resolve_indirect_refs(). The static function free_leaf_list() is
moved up for this to be possible and it's slightly simplified by removing
unnecessary code.

Fixes: 3301958b7c1d ("Btrfs: add inodes before dropping the extent lock in find_all_leafs")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 18:14:19 +01:00
Filipe Manana
57e157749a btrfs: fix processing of delayed tree block refs during backref walking
[ Upstream commit 943553ef9b51db303ab2b955c1025261abfdf6fb ]

During backref walking, when processing a delayed reference with a type of
BTRFS_TREE_BLOCK_REF_KEY, we have two bugs there:

1) We are accessing the delayed references extent_op, and its key, without
   the protection of the delayed ref head's lock;

2) If there's no extent op for the delayed ref head, we end up with an
   uninitialized key in the stack, variable 'tmp_op_key', and then pass
   it to add_indirect_ref(), which adds the reference to the indirect
   refs rb tree.

   This is wrong, because indirect references should have a NULL key
   when we don't have access to the key, and in that case they should be
   added to the indirect_missing_keys rb tree and not to the indirect rb
   tree.

   This means that if have BTRFS_TREE_BLOCK_REF_KEY delayed ref resulting
   from freeing an extent buffer, therefore with a count of -1, it will
   not cancel out the corresponding reference we have in the extent tree
   (with a count of 1), since both references end up in different rb
   trees.

   When using fiemap, where we often need to check if extents are shared
   through shared subtrees resulting from snapshots, it means we can
   incorrectly report an extent as shared when it's no longer shared.
   However this is temporary because after the transaction is committed
   the extent is no longer reported as shared, as running the delayed
   reference results in deleting the tree block reference from the extent
   tree.

   Outside the fiemap context, the result is unpredictable, as the key was
   not initialized but it's used when navigating the rb trees to insert
   and search for references (prelim_ref_compare()), and we expect all
   references in the indirect rb tree to have valid keys.

The following reproducer triggers the second bug:

   $ cat test.sh
   #!/bin/bash

   DEV=/dev/sdj
   MNT=/mnt/sdj

   mkfs.btrfs -f $DEV
   mount -o compress $DEV $MNT

   # With a compressed 128M file we get a tree height of 2 (level 1 root).
   xfs_io -f -c "pwrite -b 1M 0 128M" $MNT/foo

   btrfs subvolume snapshot $MNT $MNT/snap

   # Fiemap should output 0x2008 in the flags column.
   # 0x2000 means shared extent
   # 0x8 means encoded extent (because it's compressed)
   echo
   echo "fiemap after snapshot, range [120M, 120M + 128K):"
   xfs_io -c "fiemap -v 120M 128K" $MNT/foo
   echo

   # Overwrite one extent and fsync to flush delalloc and COW a new path
   # in the snapshot's tree.
   #
   # After this we have a BTRFS_DROP_DELAYED_REF delayed ref of type
   # BTRFS_TREE_BLOCK_REF_KEY with a count of -1 for every COWed extent
   # buffer in the path.
   #
   # In the extent tree we have inline references of type
   # BTRFS_TREE_BLOCK_REF_KEY, with a count of 1, for the same extent
   # buffers, so they should cancel each other, and the extent buffers in
   # the fs tree should no longer be considered as shared.
   #
   echo "Overwriting file range [120M, 120M + 128K)..."
   xfs_io -c "pwrite -b 128K 120M 128K" $MNT/snap/foo
   xfs_io -c "fsync" $MNT/snap/foo

   # Fiemap should output 0x8 in the flags column. The extent in the range
   # [120M, 120M + 128K) is no longer shared, it's now exclusive to the fs
   # tree.
   echo
   echo "fiemap after overwrite range [120M, 120M + 128K):"
   xfs_io -c "fiemap -v 120M 128K" $MNT/foo
   echo

   umount $MNT

Running it before this patch:

   $ ./test.sh
   (...)
   wrote 134217728/134217728 bytes at offset 0
   128 MiB, 128 ops; 0.1152 sec (1.085 GiB/sec and 1110.5809 ops/sec)
   Create a snapshot of '/mnt/sdj' in '/mnt/sdj/snap'

   fiemap after snapshot, range [120M, 120M + 128K):
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [245760..246015]: 34304..34559       256 0x2008

   Overwriting file range [120M, 120M + 128K)...
   wrote 131072/131072 bytes at offset 125829120
   128 KiB, 1 ops; 0.0001 sec (683.060 MiB/sec and 5464.4809 ops/sec)

   fiemap after overwrite range [120M, 120M + 128K):
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [245760..246015]: 34304..34559       256 0x2008

The extent in the range [120M, 120M + 128K) is still reported as shared
(0x2000 bit set) after overwriting that range and flushing delalloc, which
is not correct - an entire path was COWed in the snapshot's tree and the
extent is now only referenced by the original fs tree.

Running it after this patch:

   $ ./test.sh
   (...)
   wrote 134217728/134217728 bytes at offset 0
   128 MiB, 128 ops; 0.1198 sec (1.043 GiB/sec and 1068.2067 ops/sec)
   Create a snapshot of '/mnt/sdj' in '/mnt/sdj/snap'

   fiemap after snapshot, range [120M, 120M + 128K):
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [245760..246015]: 34304..34559       256 0x2008

   Overwriting file range [120M, 120M + 128K)...
   wrote 131072/131072 bytes at offset 125829120
   128 KiB, 1 ops; 0.0001 sec (694.444 MiB/sec and 5555.5556 ops/sec)

   fiemap after overwrite range [120M, 120M + 128K):
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [245760..246015]: 34304..34559       256   0x8

Now the extent is not reported as shared anymore.

So fix this by passing a NULL key pointer to add_indirect_ref() when
processing a delayed reference for a tree block if there's no extent op
for our delayed ref head with a defined key. Also access the extent op
only after locking the delayed ref head's lock.

The reproducer will be converted later to a test case for fstests.

Fixes: 86d5f994425252 ("btrfs: convert prelimary reference tracking to use rbtrees")
Fixes: a6dbceafb915e8 ("btrfs: Remove unused op_key var from add_delayed_refs")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:16 +01:00
Filipe Manana
590929ef69 btrfs: fix processing of delayed data refs during backref walking
[ Upstream commit 4fc7b57228243d09c0d878873bf24fa64a90fa01 ]

When processing delayed data references during backref walking and we are
using a share context (we are being called through fiemap), whenever we
find a delayed data reference for an inode different from the one we are
interested in, then we immediately exit and consider the data extent as
shared. This is wrong, because:

1) This might be a DROP reference that will cancel out a reference in the
   extent tree;

2) Even if it's an ADD reference, it may be followed by a DROP reference
   that cancels it out.

In either case we should not exit immediately.

Fix this by never exiting when we find a delayed data reference for
another inode - instead add the reference and if it does not cancel out
other delayed reference, we will exit early when we call
extent_is_shared() after processing all delayed references. If we find
a drop reference, then signal the code that processes references from
the extent tree (add_inline_refs() and add_keyed_refs()) to not exit
immediately if it finds there a reference for another inode, since we
have delayed drop references that may cancel it out. In this later case
we exit once we don't have references in the rb trees that cancel out
each other and have two references for different inodes.

Example reproducer for case 1):

   $ cat test-1.sh
   #!/bin/bash

   DEV=/dev/sdj
   MNT=/mnt/sdj

   mkfs.btrfs -f $DEV
   mount $DEV $MNT

   xfs_io -f -c "pwrite 0 64K" $MNT/foo
   cp --reflink=always $MNT/foo $MNT/bar

   echo
   echo "fiemap after cloning:"
   xfs_io -c "fiemap -v" $MNT/foo

   rm -f $MNT/bar
   echo
   echo "fiemap after removing file bar:"
   xfs_io -c "fiemap -v" $MNT/foo

   umount $MNT

Running it before this patch, the extent is still listed as shared, it has
the flag 0x2000 (FIEMAP_EXTENT_SHARED) set:

   $ ./test-1.sh
   fiemap after cloning:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128 0x2001

   fiemap after removing file bar:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128 0x2001

Example reproducer for case 2):

   $ cat test-2.sh
   #!/bin/bash

   DEV=/dev/sdj
   MNT=/mnt/sdj

   mkfs.btrfs -f $DEV
   mount $DEV $MNT

   xfs_io -f -c "pwrite 0 64K" $MNT/foo
   cp --reflink=always $MNT/foo $MNT/bar

   # Flush delayed references to the extent tree and commit current
   # transaction.
   sync

   echo
   echo "fiemap after cloning:"
   xfs_io -c "fiemap -v" $MNT/foo

   rm -f $MNT/bar
   echo
   echo "fiemap after removing file bar:"
   xfs_io -c "fiemap -v" $MNT/foo

   umount $MNT

Running it before this patch, the extent is still listed as shared, it has
the flag 0x2000 (FIEMAP_EXTENT_SHARED) set:

   $ ./test-2.sh
   fiemap after cloning:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128 0x2001

   fiemap after removing file bar:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128 0x2001

After this patch, after deleting bar in both tests, the extent is not
reported with the 0x2000 flag anymore, it gets only the flag 0x1
(which is FIEMAP_EXTENT_LAST):

   $ ./test-1.sh
   fiemap after cloning:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128 0x2001

   fiemap after removing file bar:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128   0x1

   $ ./test-2.sh
   fiemap after cloning:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128 0x2001

   fiemap after removing file bar:
   /mnt/sdj/foo:
    EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
      0: [0..127]:        26624..26751       128   0x1

These tests will later be converted to a test case for fstests.

Fixes: dc046b10c8b7d4 ("Btrfs: make fiemap not blow when you have lots of snapshots")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:16 +01:00
Qu Wenruo
70f8b48d0b btrfs: scrub: try to fix super block errors
[ Upstream commit f9eab5f0bba76742af654f33d517bf62a0db8f12 ]

[BUG]
The following script shows that, although scrub can detect super block
errors, it never tries to fix it:

	mkfs.btrfs -f -d raid1 -m raid1 $dev1 $dev2
	xfs_io -c "pwrite 67108864 4k" $dev2

	mount $dev1 $mnt
	btrfs scrub start -B $dev2
	btrfs scrub start -Br $dev2
	umount $mnt

The first scrub reports the super error correctly:

  scrub done for f3289218-abd3-41ac-a630-202f766c0859
  Scrub started:    Tue Aug  2 14:44:11 2022
  Status:           finished
  Duration:         0:00:00
  Total to scrub:   1.26GiB
  Rate:             0.00B/s
  Error summary:    super=1
    Corrected:      0
    Uncorrectable:  0
    Unverified:     0

But the second read-only scrub still reports the same super error:

  Scrub started:    Tue Aug  2 14:44:11 2022
  Status:           finished
  Duration:         0:00:00
  Total to scrub:   1.26GiB
  Rate:             0.00B/s
  Error summary:    super=1
    Corrected:      0
    Uncorrectable:  0
    Unverified:     0

[CAUSE]
The comments already shows that super block can be easily fixed by
committing a transaction:

	/*
	 * If we find an error in a super block, we just report it.
	 * They will get written with the next transaction commit
	 * anyway
	 */

But the truth is, such assumption is not always true, and since scrub
should try to repair every error it found (except for read-only scrub),
we should really actively commit a transaction to fix this.

[FIX]
Just commit a transaction if we found any super block errors, after
everything else is done.

We cannot do this just after scrub_supers(), as
btrfs_commit_transaction() will try to pause and wait for the running
scrub, thus we can not call it with scrub_lock hold.

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: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:51 +02:00
Filipe Manana
47b5ffe863 btrfs: fix race between quota enable and quota rescan ioctl
commit 331cd9461412e103d07595a10289de90004ac890 upstream.

When enabling quotas, at btrfs_quota_enable(), after committing the
transaction, we change fs_info->quota_root to point to the quota root we
created and set BTRFS_FS_QUOTA_ENABLED at fs_info->flags. Then we try
to start the qgroup rescan worker, first by initializing it with a call
to qgroup_rescan_init() - however if that fails we end up freeing the
quota root but we leave fs_info->quota_root still pointing to it, this
can later result in a use-after-free somewhere else.

We have previously set the flags BTRFS_FS_QUOTA_ENABLED and
BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with -EINPROGRESS at
btrfs_quota_enable(), which is possible if someone already called the
quota rescan ioctl, and therefore started the rescan worker.

So fix this by ignoring an -EINPROGRESS and asserting we can't get any
other error.

Reported-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/linux-btrfs/20220823015931.421355-1-yebin10@huawei.com/
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@suse.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>
2022-10-26 13:25:12 +02:00
Filipe Manana
6ac5b52e3f btrfs: fix hang during unmount when stopping a space reclaim worker
[ Upstream commit a362bb864b8db4861977d00bd2c3222503ccc34b ]

Often when running generic/562 from fstests we can hang during unmount,
resulting in a trace like this:

  Sep 07 11:52:00 debian9 unknown: run fstests generic/562 at 2022-09-07 11:52:00
  Sep 07 11:55:32 debian9 kernel: INFO: task umount:49438 blocked for more than 120 seconds.
  Sep 07 11:55:32 debian9 kernel:       Not tainted 6.0.0-rc2-btrfs-next-122 #1
  Sep 07 11:55:32 debian9 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  Sep 07 11:55:32 debian9 kernel: task:umount          state:D stack:    0 pid:49438 ppid: 25683 flags:0x00004000
  Sep 07 11:55:32 debian9 kernel: Call Trace:
  Sep 07 11:55:32 debian9 kernel:  <TASK>
  Sep 07 11:55:32 debian9 kernel:  __schedule+0x3c8/0xec0
  Sep 07 11:55:32 debian9 kernel:  ? rcu_read_lock_sched_held+0x12/0x70
  Sep 07 11:55:32 debian9 kernel:  schedule+0x5d/0xf0
  Sep 07 11:55:32 debian9 kernel:  schedule_timeout+0xf1/0x130
  Sep 07 11:55:32 debian9 kernel:  ? lock_release+0x224/0x4a0
  Sep 07 11:55:32 debian9 kernel:  ? lock_acquired+0x1a0/0x420
  Sep 07 11:55:32 debian9 kernel:  ? trace_hardirqs_on+0x2c/0xd0
  Sep 07 11:55:32 debian9 kernel:  __wait_for_common+0xac/0x200
  Sep 07 11:55:32 debian9 kernel:  ? usleep_range_state+0xb0/0xb0
  Sep 07 11:55:32 debian9 kernel:  __flush_work+0x26d/0x530
  Sep 07 11:55:32 debian9 kernel:  ? flush_workqueue_prep_pwqs+0x140/0x140
  Sep 07 11:55:32 debian9 kernel:  ? trace_clock_local+0xc/0x30
  Sep 07 11:55:32 debian9 kernel:  __cancel_work_timer+0x11f/0x1b0
  Sep 07 11:55:32 debian9 kernel:  ? close_ctree+0x12b/0x5b3 [btrfs]
  Sep 07 11:55:32 debian9 kernel:  ? __trace_bputs+0x10b/0x170
  Sep 07 11:55:32 debian9 kernel:  close_ctree+0x152/0x5b3 [btrfs]
  Sep 07 11:55:32 debian9 kernel:  ? evict_inodes+0x166/0x1c0
  Sep 07 11:55:32 debian9 kernel:  generic_shutdown_super+0x71/0x120
  Sep 07 11:55:32 debian9 kernel:  kill_anon_super+0x14/0x30
  Sep 07 11:55:32 debian9 kernel:  btrfs_kill_super+0x12/0x20 [btrfs]
  Sep 07 11:55:32 debian9 kernel:  deactivate_locked_super+0x2e/0xa0
  Sep 07 11:55:32 debian9 kernel:  cleanup_mnt+0x100/0x160
  Sep 07 11:55:32 debian9 kernel:  task_work_run+0x59/0xa0
  Sep 07 11:55:32 debian9 kernel:  exit_to_user_mode_prepare+0x1a6/0x1b0
  Sep 07 11:55:32 debian9 kernel:  syscall_exit_to_user_mode+0x16/0x40
  Sep 07 11:55:32 debian9 kernel:  do_syscall_64+0x48/0x90
  Sep 07 11:55:32 debian9 kernel:  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  Sep 07 11:55:32 debian9 kernel: RIP: 0033:0x7fcde59a57a7
  Sep 07 11:55:32 debian9 kernel: RSP: 002b:00007ffe914217c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
  Sep 07 11:55:32 debian9 kernel: RAX: 0000000000000000 RBX: 00007fcde5ae8264 RCX: 00007fcde59a57a7
  Sep 07 11:55:32 debian9 kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055b57556cdd0
  Sep 07 11:55:32 debian9 kernel: RBP: 000055b57556cba0 R08: 0000000000000000 R09: 00007ffe91420570
  Sep 07 11:55:32 debian9 kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  Sep 07 11:55:32 debian9 kernel: R13: 000055b57556cdd0 R14: 000055b57556ccb8 R15: 0000000000000000
  Sep 07 11:55:32 debian9 kernel:  </TASK>

What happens is the following:

1) The cleaner kthread tries to start a transaction to delete an unused
   block group, but the metadata reservation can not be satisfied right
   away, so a reservation ticket is created and it starts the async
   metadata reclaim task (fs_info->async_reclaim_work);

2) Writeback for all the filler inodes with an i_size of 2K starts
   (generic/562 creates a lot of 2K files with the goal of filling
   metadata space). We try to create an inline extent for them, but we
   fail when trying to insert the inline extent with -ENOSPC (at
   cow_file_range_inline()) - since this is not critical, we fallback
   to non-inline mode (back to cow_file_range()), reserve extents, create
   extent maps and create the ordered extents;

3) An unmount starts, enters close_ctree();

4) The async reclaim task is flushing stuff, entering the flush states one
   by one, until it reaches RUN_DELAYED_IPUTS. There it runs all current
   delayed iputs.

   After running the delayed iputs and before calling
   btrfs_wait_on_delayed_iputs(), one or more ordered extents complete,
   and btrfs_add_delayed_iput() is called for each one through
   btrfs_finish_ordered_io() -> btrfs_put_ordered_extent(). This results
   in bumping fs_info->nr_delayed_iputs from 0 to some positive value.

   So the async reclaim task blocks at btrfs_wait_on_delayed_iputs() waiting
   for fs_info->nr_delayed_iputs to become 0;

5) The current transaction is committed by the transaction kthread, we then
   start unpinning extents and end up calling btrfs_try_granting_tickets()
   through unpin_extent_range(), since we released some space.
   This results in satisfying the ticket created by the cleaner kthread at
   step 1, waking up the cleaner kthread;

6) At close_ctree() we ask the cleaner kthread to park;

7) The cleaner kthread starts the transaction, deletes the unused block
   group, and then calls kthread_should_park(), which returns true, so it
   parks. And at this point we have the delayed iputs added by the
   completion of the ordered extents still pending;

8) Then later at close_ctree(), when we call:

       cancel_work_sync(&fs_info->async_reclaim_work);

   We hang forever, since the cleaner was parked and no one else can run
   delayed iputs after that, while the reclaim task is waiting for the
   remaining delayed iputs to be completed.

Fix this by waiting for all ordered extents to complete and running the
delayed iputs before attempting to stop the async reclaim tasks. Note that
we can not wait for ordered extents with btrfs_wait_ordered_roots() (or
other similar functions) because that waits for the BTRFS_ORDERED_COMPLETE
flag to be set on an ordered extent, but the delayed iput is added after
that, when doing the final btrfs_put_ordered_extent(). So instead wait for
the work queues used for executing ordered extent completion to be empty,
which works because we do the final put on an ordered extent at
btrfs_finish_ordered_io() (while we are in the unmount context).

Fixes: d6fd0ae25c6495 ("Btrfs: fix missing delayed iputs on unmount")
CC: stable@vger.kernel.org # 5.15+
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: Sasha Levin <sashal@kernel.org>
2022-10-05 10:38:37 +02:00
Anand Jain
7f73a9dea0 btrfs: harden identification of a stale device
commit 770c79fb65506fc7c16459855c3839429f46cb32 upstream.

Identifying and removing the stale device from the fs_uuids list is done
by btrfs_free_stale_devices().  btrfs_free_stale_devices() in turn
depends on device_path_matched() to check if the device appears in more
than one btrfs_device structure.

The matching of the device happens by its path, the device path. However,
when device mapper is in use, the dm device paths are nothing but a link
to the actual block device, which leads to the device_path_matched()
failing to match.

Fix this by matching the dev_t as provided by lookup_bdev() instead of
plain string compare of the device paths.

Reported-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-08 11:11:40 +02:00
Goldwyn Rodrigues
d2bd18d50c btrfs: check if root is readonly while setting security xattr
commit b51111271b0352aa596c5ae8faf06939e91b3b68 upstream.

For a filesystem which has btrfs read-only property set to true, all
write operations including xattr should be denied. However, security
xattr can still be changed even if btrfs ro property is true.

This happens because xattr_permission() does not have any restrictions
on security.*, system.*  and in some cases trusted.* from VFS and
the decision is left to the underlying filesystem. See comments in
xattr_permission() for more details.

This patch checks if the root is read-only before performing the set
xattr operation.

Testcase:

  DEV=/dev/vdb
  MNT=/mnt

  mkfs.btrfs -f $DEV
  mount $DEV $MNT
  echo "file one" > $MNT/f1

  setfattr -n "security.one" -v 2 $MNT/f1
  btrfs property set /mnt ro true

  setfattr -n "security.one" -v 1 $MNT/f1

  umount $MNT

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
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>
2022-08-31 17:15:22 +02:00
Anand Jain
dcac6293f5 btrfs: add info when mount fails due to stale replace target
commit f2c3bec215694fb8bc0ef5010f2a758d1906fc2d upstream.

If the replace target device reappears after the suspended replace is
cancelled, it blocks the mount operation as it can't find the matching
replace-item in the metadata. As shown below,

   BTRFS error (device sda5): replace devid present without an active replace item

To overcome this situation, the user can run the command

   btrfs device scan --forget <replace target device>

and try the mount command again. And also, to avoid repeating the issue,
superblock on the devid=0 must be wiped.

   wipefs -a device-path-to-devid=0.

This patch adds some info when this situation occurs.

Reported-by: Samuel Greiner <samuel@balkonien.org>
Link: https://lore.kernel.org/linux-btrfs/b4f62b10-b295-26ea-71f9-9a5c9299d42c@balkonien.org/T/
CC: stable@vger.kernel.org # 5.0+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:22 +02:00
Anand Jain
b2d352ed4d btrfs: replace: drop assert for suspended replace
commit 59a3991984dbc1fc47e5651a265c5200bd85464e upstream.

If the filesystem mounts with the replace-operation in a suspended state
and try to cancel the suspended replace-operation, we hit the assert. The
assert came from the commit fe97e2e173af ("btrfs: dev-replace: replace's
scrub must not be running in suspended state") that was actually not
required. So just remove it.

 $ mount /dev/sda5 /btrfs

    BTRFS info (device sda5): cannot continue dev_replace, tgtdev is missing
    BTRFS info (device sda5): you may cancel the operation after 'mount -o degraded'

 $ mount -o degraded /dev/sda5 /btrfs <-- success.

 $ btrfs replace cancel /btrfs

    kernel: assertion failed: ret != -ENOTCONN, in fs/btrfs/dev-replace.c:1131
    kernel: ------------[ cut here ]------------
    kernel: kernel BUG at fs/btrfs/ctree.h:3750!

After the patch:

 $ btrfs replace cancel /btrfs

    BTRFS info (device sda5): suspended dev_replace from /dev/sda5 (devid 1) to <missing disk> canceled

Fixes: fe97e2e173af ("btrfs: dev-replace: replace's scrub must not be running in suspended state")
CC: stable@vger.kernel.org # 5.0+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:22 +02:00
Filipe Manana
2fc3c168d5 btrfs: fix silent failure when deleting root reference
commit 47bf225a8d2cccb15f7e8d4a1ed9b757dd86afd7 upstream.

At btrfs_del_root_ref(), if btrfs_search_slot() returns an error, we end
up returning from the function with a value of 0 (success). This happens
because the function returns the value stored in the variable 'err',
which is 0, while the error value we got from btrfs_search_slot() is
stored in the 'ret' variable.

So fix it by setting 'err' with the error value.

Fixes: 8289ed9f93bef2 ("btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Qu Wenruo <wqu@suse.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:21 +02:00
Filipe Manana
6359850f9d btrfs: fix lost error handling when looking up extended ref on log replay
commit 7a6b75b79902e47f46328b57733f2604774fa2d9 upstream.

During log replay, when processing inode references, if we get an error
when looking up for an extended reference at __add_inode_ref(), we ignore
it and proceed, returning success (0) if no other error happens after the
lookup. This is obviously wrong because in case an extended reference
exists and it encodes some name not in the log, we need to unlink it,
otherwise the filesystem state will not match the state it had after the
last fsync.

So just make __add_inode_ref() return an error it gets from the extended
reference lookup.

Fixes: f186373fef005c ("btrfs: extended inode refs")
CC: stable@vger.kernel.org # 4.9+
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>
2022-08-25 11:37:51 +02:00
Qu Wenruo
fb4e220e1b btrfs: raid56: don't trust any cached sector in __raid56_parity_recover()
commit f6065f8edeb25f4a9dfe0b446030ad995a84a088 upstream.

[BUG]
There is a small workload which will always fail with recent kernel:
(A simplified version from btrfs/125 test case)

  mkfs.btrfs -f -m raid5 -d raid5 -b 1G $dev1 $dev2 $dev3
  mount $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xee 0 1M" $mnt/file1
  sync
  umount $mnt
  btrfs dev scan -u $dev3
  mount -o degraded $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xff 0 128M" $mnt/file2
  umount $mnt
  btrfs dev scan
  mount $dev1 $mnt
  btrfs balance start --full-balance $mnt
  umount $mnt

The failure is always failed to read some tree blocks:

  BTRFS info (device dm-4): relocating block group 217710592 flags data|raid5
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  ...

[CAUSE]
With the recently added debug output, we can see all RAID56 operations
related to full stripe 38928384:

  56.1183: raid56_read_partial: full_stripe=38928384 devid=2 type=DATA1 offset=0 opf=0x0 physical=9502720 len=65536
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=16384 opf=0x0 physical=9519104 len=16384
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x0 physical=9551872 len=16384
  56.1187: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=0 opf=0x1 physical=9502720 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=32768 opf=0x1 physical=9535488 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=0 opf=0x1 physical=30474240 len=16384
  56.1189: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=32768 opf=0x1 physical=30507008 len=16384
  56.1218: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x1 physical=9551872 len=16384
  56.1219: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=49152 opf=0x1 physical=30523392 len=16384
  56.2721: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2723: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2724: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2

Before we enter raid56_parity_recover(), we have triggered some metadata
write for the full stripe 38928384, this leads to us to read all the
sectors from disk.

Furthermore, btrfs raid56 write will cache its calculated P/Q sectors to
avoid unnecessary read.

This means, for that full stripe, after any partial write, we will have
stale data, along with P/Q calculated using that stale data.

Thankfully due to patch "btrfs: only write the sectors in the vertical stripe
which has data stripes" we haven't submitted all the corrupted P/Q to disk.

When we really need to recover certain range, aka in
raid56_parity_recover(), we will use the cached rbio, along with its
cached sectors (the full stripe is all cached).

This explains why we have no event raid56_scrub_read_recover()
triggered.

Since we have the cached P/Q which is calculated using the stale data,
the recovered one will just be stale.

In our particular test case, it will always return the same incorrect
metadata, thus causing the same error message "parent transid verify
failed on 39010304 wanted 9 found 7" again and again.

[BTRFS DESTRUCTIVE RMW PROBLEM]

Test case btrfs/125 (and above workload) always has its trouble with
the destructive read-modify-write (RMW) cycle:

        0       32K     64K
Data1:  | Good  | Good  |
Data2:  | Bad   | Bad   |
Parity: | Good  | Good  |

In above case, if we trigger any write into Data1, we will use the bad
data in Data2 to re-generate parity, killing the only chance to recovery
Data2, thus Data2 is lost forever.

This destructive RMW cycle is not specific to btrfs RAID56, but there
are some btrfs specific behaviors making the case even worse:

- Btrfs will cache sectors for unrelated vertical stripes.

  In above example, if we're only writing into 0~32K range, btrfs will
  still read data range (32K ~ 64K) of Data1, and (64K~128K) of Data2.
  This behavior is to cache sectors for later update.

  Incidentally commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio()
  subpage compatible") has a bug which makes RAID56 to never trust the
  cached sectors, thus slightly improve the situation for recovery.

  Unfortunately, follow up fix "btrfs: update stripe_sectors::uptodate in
  steal_rbio" will revert the behavior back to the old one.

- Btrfs raid56 partial write will update all P/Q sectors and cache them

  This means, even if data at (64K ~ 96K) of Data2 is free space, and
  only (96K ~ 128K) of Data2 is really stale data.
  And we write into that (96K ~ 128K), we will update all the parity
  sectors for the full stripe.

  This unnecessary behavior will completely kill the chance of recovery.

  Thankfully, an unrelated optimization "btrfs: only write the sectors
  in the vertical stripe which has data stripes" will prevent
  submitting the write bio for untouched vertical sectors.

  That optimization will keep the on-disk P/Q untouched for a chance for
  later recovery.

[FIX]
Although we have no good way to completely fix the destructive RMW
(unless we go full scrub for each partial write), we can still limit the
damage.

With patch "btrfs: only write the sectors in the vertical stripe which
has data stripes" now we won't really submit the P/Q of unrelated
vertical stripes, so the on-disk P/Q should still be fine.

Now we really need to do is just drop all the cached sectors when doing
recovery.

By this, we have a chance to read the original P/Q from disk, and have a
chance to recover the stale data, while still keep the cache to speed up
regular write path.

In fact, just dropping all the cache for recovery path is good enough to
allow the test case btrfs/125 along with the small script to pass
reliably.

The lack of metadata write after the degraded mount, and forced metadata
COW is saving us this time.

So this patch will fix the behavior by not trust any cache in
__raid56_parity_recover(), to solve the problem while still keep the
cache useful.

But please note that this test pass DOES NOT mean we have solved the
destructive RMW problem, we just do better damage control a little
better.

Related patches:

- btrfs: only write the sectors in the vertical stripe
- d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage compatible")
- btrfs: update stripe_sectors::uptodate in steal_rbio

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:27 +02:00
Qu Wenruo
1e1a039f44 btrfs: only write the sectors in the vertical stripe which has data stripes
commit bd8f7e627703ca5707833d623efcd43f104c7b3f upstream.

If we have only 8K partial write at the beginning of a full RAID56
stripe, we will write the following contents:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XXXXXXXXXXXXXXX|XXXXXXXXXXXXXXX|

|X| means the sector will be written back to disk.

Note that, although we won't write any sectors from disk 2, but we will
write the full 64KiB of parity to disk.

This behavior is fine for now, but not for the future (especially for
RAID56J, as we waste quite some space to journal the unused parity
stripes).

So here we will also utilize the btrfs_raid_bio::dbitmap, anytime we
queue a higher level bio into an rbio, we will update rbio::dbitmap to
indicate which vertical stripes we need to writeback.

And at finish_rmw(), we also check dbitmap to see if we need to write
any sector in the vertical stripe.

So after the patch, above example will only lead to the following
writeback pattern:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XX|            |               |

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:27 +02:00
Josef Bacik
40d28ae576 btrfs: reset block group chunk force if we have to wait
[ Upstream commit 1314ca78b2c35d3e7d0f097268a2ee6dc0d369ef ]

If you try to force a chunk allocation, but you race with another chunk
allocation, you will end up waiting on the chunk allocation that just
occurred and then allocate another chunk.  If you have many threads all
doing this at once you can way over-allocate chunks.

Fix this by resetting force to NO_FORCE, that way if we think we need to
allocate we can, otherwise we don't force another chunk allocation if
one is already happening.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:20 +02:00
Qu Wenruo
e2f1507303 btrfs: reject log replay if there is unsupported RO compat flag
[ Upstream commit dc4d31684974d140250f3ee612c3f0cab13b3146 ]

[BUG]
If we have a btrfs image with dirty log, along with an unsupported RO
compatible flag:

log_root		30474240
...
compat_flags		0x0
compat_ro_flags		0x40000003
			( FREE_SPACE_TREE |
			  FREE_SPACE_TREE_VALID |
			  unknown flag: 0x40000000 )

Then even if we can only mount it RO, we will still cause metadata
update for log replay:

  BTRFS info (device dm-1): flagging fs with big metadata feature
  BTRFS info (device dm-1): using free space tree
  BTRFS info (device dm-1): has skinny extents
  BTRFS info (device dm-1): start tree-log replay

This is definitely against RO compact flag requirement.

[CAUSE]
RO compact flag only forces us to do RO mount, but we will still do log
replay for plain RO mount.

Thus this will result us to do log replay and update metadata.

This can be very problematic for new RO compat flag, for example older
kernel can not understand v2 cache, and if we allow metadata update on
RO mount and invalidate/corrupt v2 cache.

[FIX]
Just reject the mount unless rescue=nologreplay is provided:

  BTRFS error (device dm-1): cannot replay dirty log with unsupport optional features (0x40000000), try rescue=nologreplay instead

We don't want to set rescue=nologreply directly, as this would make the
end user to read the old data, and cause confusion.

Since the such case is really rare, we're mostly fine to just reject the
mount with an error message, which also includes the proper workaround.

CC: stable@vger.kernel.org #4.9+
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: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:20 +02:00
Filipe Manana
c1ea39a77c btrfs: return -EAGAIN for NOWAIT dio reads/writes on compressed and inline extents
commit a4527e1853f8ff6e0b7c2dadad6268bd38427a31 upstream.

When doing a direct IO read or write, we always return -ENOTBLK when we
find a compressed extent (or an inline extent) so that we fallback to
buffered IO. This however is not ideal in case we are in a NOWAIT context
(io_uring for example), because buffered IO can block and we currently
have no support for NOWAIT semantics for buffered IO, so if we need to
fallback to buffered IO we should first signal the caller that we may
need to block by returning -EAGAIN instead.

This behaviour can also result in short reads being returned to user
space, which although it's not incorrect and user space should be able
to deal with partial reads, it's somewhat surprising and even some popular
applications like QEMU (Link tag #1) and MariaDB (Link tag #2) don't
deal with short reads properly (or at all).

The short read case happens when we try to read from a range that has a
non-compressed and non-inline extent followed by a compressed extent.
After having read the first extent, when we find the compressed extent we
return -ENOTBLK from btrfs_dio_iomap_begin(), which results in iomap to
treat the request as a short read, returning 0 (success) and waiting for
previously submitted bios to complete (this happens at
fs/iomap/direct-io.c:__iomap_dio_rw()). After that, and while at
btrfs_file_read_iter(), we call filemap_read() to use buffered IO to
read the remaining data, and pass it the number of bytes we were able to
read with direct IO. Than at filemap_read() if we get a page fault error
when accessing the read buffer, we return a partial read instead of an
-EFAULT error, because the number of bytes previously read is greater
than zero.

So fix this by returning -EAGAIN for NOWAIT direct IO when we find a
compressed or an inline extent.

Reported-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
Link: https://lore.kernel.org/linux-btrfs/YrrFGO4A1jS0GI0G@atmark-techno.com/
Link: https://jira.mariadb.org/browse/MDEV-27900?focusedCommentId=216582&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-216582
Tested-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
2022-07-21 21:20:01 +02:00
David Sterba
0ae82e1ccb btrfs: add error messages to all unrecognized mount options
commit e3a4167c880cf889f66887a152799df4d609dd21 upstream.

Almost none of the errors stemming from a valid mount option but wrong
value prints a descriptive message which would help to identify why
mount failed. Like in the linked report:

  $ uname -r
  v4.19
  $ mount -o compress=zstd /dev/sdb /mnt
  mount: /mnt: wrong fs type, bad option, bad superblock on
  /dev/sdb, missing codepage or helper program, or other error.
  $ dmesg
  ...
  BTRFS error (device sdb): open_ctree failed

Errors caused by memory allocation failures are left out as it's not a
user error so reporting that would be confusing.

Link: https://lore.kernel.org/linux-btrfs/9c3fec36-fc61-3a33-4977-a7e207c3fa4e@gmx.de/
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@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>
2022-06-29 08:59:45 +02:00
Qu Wenruo
509e9710b8 btrfs: repair super block num_devices automatically
commit d201238ccd2f30b9bfcfadaeae0972e3a486a176 upstream.

[BUG]
There is a report that a btrfs has a bad super block num devices.

This makes btrfs to reject the fs completely.

  BTRFS error (device sdd3): super_num_devices 3 mismatch with num_devices 2 found here
  BTRFS error (device sdd3): failed to read chunk tree: -22
  BTRFS error (device sdd3): open_ctree failed

[CAUSE]
During btrfs device removal, chunk tree and super block num devs are
updated in two different transactions:

  btrfs_rm_device()
  |- btrfs_rm_dev_item(device)
  |  |- trans = btrfs_start_transaction()
  |  |  Now we got transaction X
  |  |
  |  |- btrfs_del_item()
  |  |  Now device item is removed from chunk tree
  |  |
  |  |- btrfs_commit_transaction()
  |     Transaction X got committed, super num devs untouched,
  |     but device item removed from chunk tree.
  |     (AKA, super num devs is already incorrect)
  |
  |- cur_devices->num_devices--;
  |- cur_devices->total_devices--;
  |- btrfs_set_super_num_devices()
     All those operations are not in transaction X, thus it will
     only be written back to disk in next transaction.

So after the transaction X in btrfs_rm_dev_item() committed, but before
transaction X+1 (which can be minutes away), a power loss happen, then
we got the super num mismatch.

This has been fixed by commit bbac58698a55 ("btrfs: remove device item
and update super block in the same transaction").

[FIX]
Make the super_num_devices check less strict, converting it from a hard
error to a warning, and reset the value to a correct one for the current
or next transaction commit.

As the number of device items is the critical information where the
super block num_devices is only a cached value (and also useful for
cross checking), it's safe to automatically update it. Other device
related problems like missing device are handled after that and may
require other means to resolve, like degraded mount. With this fix,
potentially affected filesystems won't fail mount and require the manual
repair by btrfs check.

Reported-by: Luca Béla Palkovics <luca.bela.palkovics@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CA+8xDSpvdm_U0QLBAnrH=zqDq_cWCOH5TiV46CKmp3igr44okQ@mail.gmail.com/
CC: stable@vger.kernel.org # 4.14+
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>
2022-06-09 10:20:49 +02:00
Qu Wenruo
4093eea47d btrfs: add "0x" prefix for unsupported optional features
commit d5321a0fa8bc49f11bea0b470800962c17d92d8f upstream.

The following error message lack the "0x" obviously:

  cannot mount because of unsupported optional features (4000)

Add the prefix to make it less confusing. This can happen on older
kernels that try to mount a filesystem with newer features so it makes
sense to backport to older trees.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.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>
2022-06-09 10:20:49 +02:00
Filipe Manana
4fd45ef704 btrfs: always log symlinks in full mode
commit d0e64a981fd841cb0f28fcd6afcac55e6f1e6994 upstream.

On Linux, empty symlinks are invalid, and attempting to create one with
the system call symlink(2) results in an -ENOENT error and this is
explicitly documented in the man page.

If we rename a symlink that was created in the current transaction and its
parent directory was logged before, we actually end up logging the symlink
without logging its content, which is stored in an inline extent. That
means that after a power failure we can end up with an empty symlink,
having no content and an i_size of 0 bytes.

It can be easily reproduced like this:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  $ mkdir /mnt/testdir
  $ sync

  # Create a file inside the directory and fsync the directory.
  $ touch /mnt/testdir/foo
  $ xfs_io -c "fsync" /mnt/testdir

  # Create a symlink inside the directory and then rename the symlink.
  $ ln -s /mnt/testdir/foo /mnt/testdir/bar
  $ mv /mnt/testdir/bar /mnt/testdir/baz

  # Now fsync again the directory, this persist the log tree.
  $ xfs_io -c "fsync" /mnt/testdir

  <power failure>

  $ mount /dev/sdc /mnt
  $ stat -c %s /mnt/testdir/baz
  0
  $ readlink /mnt/testdir/baz
  $

Fix this by always logging symlinks in full mode (LOG_INODE_ALL), so that
their content is also logged.

A test case for fstests will follow.

CC: stable@vger.kernel.org # 4.9+
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>
2022-05-12 12:25:43 +02:00
Naohiro Aota
5e4dd17998 btrfs: mark resumed async balance as writing
commit a690e5f2db4d1dca742ce734aaff9f3112d63764 upstream.

When btrfs balance is interrupted with umount, the background balance
resumes on the next mount. There is a potential deadlock with FS freezing
here like as described in commit 26559780b953 ("btrfs: zoned: mark
relocation as writing"). Mark the process as sb_writing to avoid it.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.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>
2022-04-20 09:23:27 +02:00
Jia-Ju Bai
1d2eda18f6 btrfs: fix root ref counts in error handling in btrfs_get_root_ref
commit 168a2f776b9762f4021421008512dd7ab7474df1 upstream.

In btrfs_get_root_ref(), when btrfs_insert_fs_root() fails,
btrfs_put_root() can happen for two reasons:

- the root already exists in the tree, in that case it returns the
  reference obtained in btrfs_lookup_fs_root()

- another error so the cleanup is done in the fail label

Calling btrfs_put_root() unconditionally would lead to double decrement
of the root reference possibly freeing it in the second case.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Fixes: bc44d7c4b2b1 ("btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.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>
2022-04-20 09:23:27 +02:00
Josef Bacik
76e086ce7b btrfs: do not warn for free space inode in cow_file_range
[ Upstream commit a7d16d9a07bbcb7dcd5214a1bea75c808830bc0d ]

This is a long time leftover from when I originally added the free space
inode, the point was to catch cases where we weren't honoring the NOCOW
flag.  However there exists a race with relocation, if we allocate our
free space inode in a block group that is about to be relocated, we
could trigger the COW path before the relocation has the opportunity to
find the extents and delete the free space cache.  In production where
we have auto-relocation enabled we're seeing this WARN_ON_ONCE() around
5k times in a 2 week period, so not super common but enough that it's at
the top of our metrics.

We're properly handling the error here, and with us phasing out v1 space
cache anyway just drop the WARN_ON_ONCE.

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>
2022-04-20 09:23:19 +02:00
Darrick J. Wong
217190dc66 btrfs: fix fallocate to use file_modified to update permissions consistently
[ Upstream commit 05fd9564e9faf0f23b4676385e27d9405cef6637 ]

Since the initial introduction of (posix) fallocate back at the turn of
the century, it has been possible to use this syscall to change the
user-visible contents of files.  This can happen by extending the file
size during a preallocation, or through any of the newer modes (punch,
zero range).  Because the call can be used to change file contents, we
should treat it like we do any other modification to a file -- update
the mtime, and drop set[ug]id privileges/capabilities.

The VFS function file_modified() does all this for us if pass it a
locked inode, so let's make fallocate drop permissions correctly.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:23:19 +02:00
Nathan Chancellor
921fdc45a0 btrfs: remove unused variable in btrfs_{start,write}_dirty_block_groups()
commit 6d4a6b515c39f1f8763093e0f828959b2fbc2f45 upstream.

Clang's version of -Wunused-but-set-variable recently gained support for
unary operations, which reveals two unused variables:

  fs/btrfs/block-group.c:2949:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
          int num_started = 0;
              ^
  fs/btrfs/block-group.c:3116:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
          int num_started = 0;
              ^
  2 errors generated.

These variables appear to be unused from their introduction, so just
remove them to silence the warnings.

Fixes: c9dc4c657850 ("Btrfs: two stage dirty block group writeout")
Fixes: 1bbc621ef284 ("Btrfs: allow block group cache writeout outside critical section in commit")
CC: stable@vger.kernel.org # 5.4+
Link: https://github.com/ClangBuiltLinux/linux/issues/1614
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:23:10 +02:00
Kaiwen Hu
a044bca8ef btrfs: prevent subvol with swapfile from being deleted
commit 60021bd754c6ca0addc6817994f20290a321d8d6 upstream.

A subvolume with an active swapfile must not be deleted otherwise it
would not be possible to deactivate it.

After the subvolume is deleted, we cannot swapoff the swapfile in this
deleted subvolume because the path is unreachable.  The swapfile is
still active and holding references, the filesystem cannot be unmounted.

The test looks like this:

  mkfs.btrfs -f $dev > /dev/null
  mount $dev $mnt

  btrfs sub create $mnt/subvol
  touch $mnt/subvol/swapfile
  chmod 600 $mnt/subvol/swapfile
  chattr +C $mnt/subvol/swapfile
  dd if=/dev/zero of=$mnt/subvol/swapfile bs=1K count=4096
  mkswap $mnt/subvol/swapfile
  swapon $mnt/subvol/swapfile

  btrfs sub delete $mnt/subvol
  swapoff $mnt/subvol/swapfile  # failed: No such file or directory
  swapoff --all

  unmount $mnt                  # target is busy.

To prevent above issue, we simply check that whether the subvolume
contains any active swapfile, and stop the deleting process.  This
behavior is like snapshot ioctl dealing with a swapfile.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Kaiwen Hu <kevinhu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-13 21:01:08 +02:00
Ethan Lien
82ae73ac96 btrfs: fix qgroup reserve overflow the qgroup limit
commit b642b52d0b50f4d398cb4293f64992d0eed2e2ce upstream.

We use extent_changeset->bytes_changed in qgroup_reserve_data() to record
how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the
bytes_changed is set as "unsigned int", and it will overflow if we try to
fallocate a range larger than 4GiB. The result is we reserve less bytes
and eventually break the qgroup limit.

Unlike regular buffered/direct write, which we use one changeset for
each ordered extent, which can never be larger than 256M.  For
fallocate, we use one changeset for the whole range, thus it no longer
respects the 256M per extent limit, and caused the problem.

The following example test script reproduces the problem:

  $ cat qgroup-overflow.sh
  #!/bin/bash

  DEV=/dev/sdj
  MNT=/mnt/sdj

  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  # Set qgroup limit to 2GiB.
  btrfs quota enable $MNT
  btrfs qgroup limit 2G $MNT

  # Try to fallocate a 3GiB file. This should fail.
  echo
  echo "Try to fallocate a 3GiB file..."
  fallocate -l 3G $MNT/3G.file

  # Try to fallocate a 5GiB file.
  echo
  echo "Try to fallocate a 5GiB file..."
  fallocate -l 5G $MNT/5G.file

  # See we break the qgroup limit.
  echo
  sync
  btrfs qgroup show -r $MNT

  umount $MNT

When running the test:

  $ ./qgroup-overflow.sh
  (...)

  Try to fallocate a 3GiB file...
  fallocate: fallocate failed: Disk quota exceeded

  Try to fallocate a 5GiB file...

  qgroupid         rfer         excl     max_rfer
  --------         ----         ----     --------
  0/5           5.00GiB      5.00GiB      2.00GiB

Since we have no control of how bytes_changed is used, it's better to
set it to u64.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Ethan Lien <ethanlien@synology.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>
2022-04-13 21:01:08 +02:00
Filipe Manana
2c4741d1b0 btrfs: fix unexpected error path when reflinking an inline extent
[ Upstream commit 1f4613cdbe7739ce291554b316bff8e551383389 ]

When reflinking an inline extent, we assert that its file offset is 0 and
that its uncompressed length is not greater than the sector size. We then
return an error if one of those conditions is not satisfied. However we
use a return statement, which results in returning from btrfs_clone()
without freeing the path and buffer that were allocated before, as well as
not clearing the flag BTRFS_INODE_NO_DELALLOC_FLUSH for the destination
inode.

Fix that by jumping to the 'out' label instead, and also add a WARN_ON()
for each condition so that in case assertions are disabled, we get to
known which of the unexpected conditions triggered the error.

Fixes: a61e1e0df9f321 ("Btrfs: simplify inline extent handling when doing reflinks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:04 +02:00
Filipe Manana
292e1c88b8 btrfs: add missing run of delayed items after unlink during log replay
commit 4751dc99627e4d1465c5bfa8cb7ab31ed418eff5 upstream.

During log replay, whenever we need to check if a name (dentry) exists in
a directory we do searches on the subvolume tree for inode references or
or directory entries (BTRFS_DIR_INDEX_KEY keys, and BTRFS_DIR_ITEM_KEY
keys as well, before kernel 5.17). However when during log replay we
unlink a name, through btrfs_unlink_inode(), we may not delete inode
references and dir index keys from a subvolume tree and instead just add
the deletions to the delayed inode's delayed items, which will only be
run when we commit the transaction used for log replay. This means that
after an unlink operation during log replay, if we attempt to search for
the same name during log replay, we will not see that the name was already
deleted, since the deletion is recorded only on the delayed items.

We run delayed items after every unlink operation during log replay,
except at unlink_old_inode_refs() and at add_inode_ref(). This was due
to an overlook, as delayed items should be run after evert unlink, for
the reasons stated above.

So fix those two cases.

Fixes: 0d836392cadd5 ("Btrfs: fix mount failure after fsync due to hard link recreation")
Fixes: 1f250e929a9c9 ("Btrfs: fix log replay failure after unlink and link combination")
CC: stable@vger.kernel.org # 4.19+
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>
2022-03-08 19:09:38 +01:00
Sidong Yang
41712c5fa5 btrfs: qgroup: fix deadlock between rescan worker and remove qgroup
commit d4aef1e122d8bbdc15ce3bd0bc813d6b44a7d63a upstream.

The commit e804861bd4e6 ("btrfs: fix deadlock between quota disable and
qgroup rescan worker") by Kawasaki resolves deadlock between quota
disable and qgroup rescan worker. But also there is a deadlock case like
it. It's about enabling or disabling quota and creating or removing
qgroup. It can be reproduced in simple script below.

for i in {1..100}
do
    btrfs quota enable /mnt &
    btrfs qgroup create 1/0 /mnt &
    btrfs qgroup destroy 1/0 /mnt &
    btrfs quota disable /mnt &
done

Here's why the deadlock happens:

1) The quota rescan task is running.

2) Task A calls btrfs_quota_disable(), locks the qgroup_ioctl_lock
   mutex, and then calls btrfs_qgroup_wait_for_completion(), to wait for
   the quota rescan task to complete.

3) Task B calls btrfs_remove_qgroup() and it blocks when trying to lock
   the qgroup_ioctl_lock mutex, because it's being held by task A. At that
   point task B is holding a transaction handle for the current transaction.

4) The quota rescan task calls btrfs_commit_transaction(). This results
   in it waiting for all other tasks to release their handles on the
   transaction, but task B is blocked on the qgroup_ioctl_lock mutex
   while holding a handle on the transaction, and that mutex is being held
   by task A, which is waiting for the quota rescan task to complete,
   resulting in a deadlock between these 3 tasks.

To resolve this issue, the thread disabling quota should unlock
qgroup_ioctl_lock before waiting rescan completion. Move
btrfs_qgroup_wait_for_completion() after unlock of qgroup_ioctl_lock.

Fixes: e804861bd4e6 ("btrfs: fix deadlock between quota disable and qgroup rescan worker")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Sidong Yang <realwakka@gmail.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>
2022-03-08 19:09:38 +01:00
Filipe Manana
6e0319e770 btrfs: fix lost prealloc extents beyond eof after full fsync
commit d99478874355d3a7b9d86dfb5d7590d5b1754b1f upstream.

When doing a full fsync, if we have prealloc extents beyond (or at) eof,
and the leaves that contain them were not modified in the current
transaction, we end up not logging them. This results in losing those
extents when we replay the log after a power failure, since the inode is
truncated to the current value of the logged i_size.

Just like for the fast fsync path, we need to always log all prealloc
extents starting at or beyond i_size. The fast fsync case was fixed in
commit 471d557afed155 ("Btrfs: fix loss of prealloc extents past i_size
after fsync log replay") but it missed the full fsync path. The problem
exists since the very early days, when the log tree was added by
commit e02119d5a7b439 ("Btrfs: Add a write ahead tree log to optimize
synchronous operations").

Example reproducer:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  # Create our test file with many file extent items, so that they span
  # several leaves of metadata, even if the node/page size is 64K. Use
  # direct IO and not fsync/O_SYNC because it's both faster and it avoids
  # clearing the full sync flag from the inode - we want the fsync below
  # to trigger the slow full sync code path.
  $ xfs_io -f -d -c "pwrite -b 4K 0 16M" /mnt/foo

  # Now add two preallocated extents to our file without extending the
  # file's size. One right at i_size, and another further beyond, leaving
  # a gap between the two prealloc extents.
  $ xfs_io -c "falloc -k 16M 1M" /mnt/foo
  $ xfs_io -c "falloc -k 20M 1M" /mnt/foo

  # Make sure everything is durably persisted and the transaction is
  # committed. This makes all created extents to have a generation lower
  # than the generation of the transaction used by the next write and
  # fsync.
  sync

  # Now overwrite only the first extent, which will result in modifying
  # only the first leaf of metadata for our inode. Then fsync it. This
  # fsync will use the slow code path (inode full sync bit is set) because
  # it's the first fsync since the inode was created/loaded.
  $ xfs_io -c "pwrite 0 4K" -c "fsync" /mnt/foo

  # Extent list before power failure.
  $ xfs_io -c "fiemap -v" /mnt/foo
  /mnt/foo:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..7]:          2178048..2178055     8   0x0
     1: [8..16383]:      26632..43007     16376   0x0
     2: [16384..32767]:  2156544..2172927 16384   0x0
     3: [32768..34815]:  2172928..2174975  2048 0x800
     4: [34816..40959]:  hole              6144
     5: [40960..43007]:  2174976..2177023  2048 0x801

  <power fail>

  # Mount fs again, trigger log replay.
  $ mount /dev/sdc /mnt

  # Extent list after power failure and log replay.
  $ xfs_io -c "fiemap -v" /mnt/foo
  /mnt/foo:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..7]:          2178048..2178055     8   0x0
     1: [8..16383]:      26632..43007     16376   0x0
     2: [16384..32767]:  2156544..2172927 16384   0x1

  # The prealloc extents at file offsets 16M and 20M are missing.

So fix this by calling btrfs_log_prealloc_extents() when we are doing a
full fsync, so that we always log all prealloc extents beyond eof.

A test case for fstests will follow soon.

CC: stable@vger.kernel.org # 4.19+
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>
2022-03-08 19:09:38 +01:00
Su Yue
72a5b01875 btrfs: tree-checker: check item_size for dev_item
commit ea1d1ca4025ac6c075709f549f9aa036b5b6597d upstream.

Check item size before accessing the device item to avoid out of bound
access, similar to inode_item check.

Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:42:45 +01:00
Su Yue
5c967dd073 btrfs: tree-checker: check item_size for inode_item
commit 0c982944af27d131d3b74242f3528169f66950ad upstream.

while mounting the crafted image, out-of-bounds access happens:

  [350.429619] UBSAN: array-index-out-of-bounds in fs/btrfs/struct-funcs.c:161:1
  [350.429636] index 1048096 is out of range for type 'page *[16]'
  [350.429650] CPU: 0 PID: 9 Comm: kworker/u8:1 Not tainted 5.16.0-rc4 #1
  [350.429652] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [350.429653] Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs]
  [350.429772] Call Trace:
  [350.429774]  <TASK>
  [350.429776]  dump_stack_lvl+0x47/0x5c
  [350.429780]  ubsan_epilogue+0x5/0x50
  [350.429786]  __ubsan_handle_out_of_bounds+0x66/0x70
  [350.429791]  btrfs_get_16+0xfd/0x120 [btrfs]
  [350.429832]  check_leaf+0x754/0x1a40 [btrfs]
  [350.429874]  ? filemap_read+0x34a/0x390
  [350.429878]  ? load_balance+0x175/0xfc0
  [350.429881]  validate_extent_buffer+0x244/0x310 [btrfs]
  [350.429911]  btrfs_validate_metadata_buffer+0xf8/0x100 [btrfs]
  [350.429935]  end_bio_extent_readpage+0x3af/0x850 [btrfs]
  [350.429969]  ? newidle_balance+0x259/0x480
  [350.429972]  end_workqueue_fn+0x29/0x40 [btrfs]
  [350.429995]  btrfs_work_helper+0x71/0x330 [btrfs]
  [350.430030]  ? __schedule+0x2fb/0xa40
  [350.430033]  process_one_work+0x1f6/0x400
  [350.430035]  ? process_one_work+0x400/0x400
  [350.430036]  worker_thread+0x2d/0x3d0
  [350.430037]  ? process_one_work+0x400/0x400
  [350.430038]  kthread+0x165/0x190
  [350.430041]  ? set_kthread_struct+0x40/0x40
  [350.430043]  ret_from_fork+0x1f/0x30
  [350.430047]  </TASK>
  [350.430077] BTRFS warning (device loop0): bad eb member start: ptr 0xffe20f4e start 20975616 member offset 4293005178 size 2

check_leaf() is checking the leaf:

  corrupt leaf: root=4 block=29396992 slot=1, bad key order, prev (16140901064495857664 1 0) current (1 204 12582912)
  leaf 29396992 items 6 free space 3565 generation 6 owner DEV_TREE
  leaf 29396992 flags 0x1(WRITTEN) backref revision 1
  fs uuid a62e00e8-e94e-4200-8217-12444de93c2e
  chunk uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8
	  item 0 key (16140901064495857664 INODE_ITEM 0) itemoff 3955 itemsize 40
		  generation 0 transid 0 size 0 nbytes 17592186044416
		  block group 0 mode 52667 links 33 uid 0 gid 2104132511 rdev 94223634821136
		  sequence 100305 flags 0x2409000(none)
		  atime 0.0 (1970-01-01 08:00:00)
		  ctime 2973280098083405823.4294967295 (-269783007-01-01 21:37:03)
		  mtime 18446744071572723616.4026825121 (1902-04-16 12:40:00)
		  otime 9249929404488876031.4294967295 (622322949-04-16 04:25:58)
	  item 1 key (1 DEV_EXTENT 12582912) itemoff 3907 itemsize 48
		  dev extent chunk_tree 3
		  chunk_objectid 256 chunk_offset 12582912 length 8388608
		  chunk_tree_uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8

The corrupted leaf of device tree has an inode item. The leaf passed
checksum and others checks in validate_extent_buffer until check_leaf_item().
Because of the key type BTRFS_INODE_ITEM, check_inode_item() is called even we
are in the device tree. Since the
item offset + sizeof(struct btrfs_inode_item) > eb->len, out-of-bounds access
is triggered.

The item end vs leaf boundary check has been done before
check_leaf_item(), so fix it by checking item size in check_inode_item()
before access of the inode item in extent buffer.

Other check functions except check_dev_item() in check_leaf_item()
have their item size checks.
The commit for check_dev_item() is followed.

No regression observed during running fstests.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215299
CC: stable@vger.kernel.org # 5.10+
CC: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:42:45 +01:00