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| author | Chris Mason <clm@fb.com> | 2016-10-27 10:42:20 -0700 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2016-10-27 10:42:20 -0700 |
| commit | 570dd45042a7c8a7aba1ee029c5dd0f5ccf41b9b (patch) | |
| tree | 8eef62c0d0b1481a4b70df1bc6b1c2e6fdbe5c2a /Documentation/acpi/DSD-properties-rules.txt | |
| parent | 112a3edf4bc687e02b9aa13c33391203fe6b7714 (diff) | |
btrfs: fix races on root_log_ctx lists
btrfs_remove_all_log_ctxs takes a shortcut where it avoids walking the
list because it knows all of the waiters are patiently waiting for the
commit to finish.
But, there's a small race where btrfs_sync_log can remove itself from
the list if it finds a log commit is already done. Also, it uses
list_del_init() to remove itself from the list, but there's no way to
know if btrfs_remove_all_log_ctxs has already run, so we don't know for
sure if it is safe to call list_del_init().
This gets rid of all the shortcuts for btrfs_remove_all_log_ctxs(), and
just calls it with the proper locking.
This is part two of the corruption fixed by cbd60aa7cd1. I should have
done this in the first place, but convinced myself the optimizations were
safe. A 12 hour run of dbench 2048 will eventually trigger a list debug
WARN_ON for the list_del_init() in btrfs_sync_log().
Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4
Reported-by: Dave Jones <davej@codemonkey.org.uk>
cc: stable@vger.kernel.org # 3.15+
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'Documentation/acpi/DSD-properties-rules.txt')