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| author | Wang Shilong <wangsl.fnst@cn.fujitsu.com> | 2014-06-19 04:42:52 +0200 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-06-19 23:20:55 +0200 |
| commit | 298a8f9cf17d2f2e1ffc41e5e247fa3695a8a76f (patch) | |
| tree | 639c13227f07fefe4eea2a13988d3792848f67bf /fs/btrfs/extent_map.h | |
| parent | btrfs: Skip scrubbing removed chunks to avoid -ENOENT. (diff) | |
| download | linux-298a8f9cf17d2f2e1ffc41e5e247fa3695a8a76f.tar.xz linux-298a8f9cf17d2f2e1ffc41e5e247fa3695a8a76f.zip | |
Btrfs: fix NULL pointer crash when running balance and scrub concurrently
While running balance, scrub, fsstress concurrently we hit the
following kernel crash:
[56561.448845] BTRFS info (device sde): relocating block group 11005853696 flags 132
[56561.524077] BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
[56561.524237] IP: [<ffffffffa038956d>] scrub_chunk.isra.12+0xdd/0x130 [btrfs]
[56561.524297] PGD 9be28067 PUD 7f3dd067 PMD 0
[56561.524325] Oops: 0000 [#1] SMP
[....]
[56561.527237] Call Trace:
[56561.527309] [<ffffffffa038980e>] scrub_enumerate_chunks+0x24e/0x490 [btrfs]
[56561.527392] [<ffffffff810abe00>] ? abort_exclusive_wait+0x50/0xb0
[56561.527476] [<ffffffffa038add4>] btrfs_scrub_dev+0x1a4/0x530 [btrfs]
[56561.527561] [<ffffffffa0368107>] btrfs_ioctl+0x13f7/0x2a90 [btrfs]
[56561.527639] [<ffffffff811c82f0>] do_vfs_ioctl+0x2e0/0x4c0
[56561.527712] [<ffffffff8109c384>] ? vtime_account_user+0x54/0x60
[56561.527788] [<ffffffff810f768c>] ? __audit_syscall_entry+0x9c/0xf0
[56561.527870] [<ffffffff811c8551>] SyS_ioctl+0x81/0xa0
[56561.527941] [<ffffffff815707f7>] tracesys+0xdd/0xe2
[...]
[56561.528304] RIP [<ffffffffa038956d>] scrub_chunk.isra.12+0xdd/0x130 [btrfs]
[56561.528395] RSP <ffff88004c0f5be8>
[56561.528454] CR2: 0000000000000078
This is because in btrfs_relocate_chunk(), we will free @bdev directly while
scrub may still hold extent mapping, and may access freed memory.
Fix this problem by wrapping freeing @bdev work into free_extent_map() which
is based on reference count.
Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/extent_map.h')
| -rw-r--r-- | fs/btrfs/extent_map.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index e7fd8a56a140..b2991fd8583e 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -15,6 +15,7 @@ #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */ #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */ #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */ +#define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */ struct extent_map { struct rb_node rb_node; |