diff options
| author | Adam Buchbinder <abuchbinder@google.com> | 2014-05-18 22:40:42 -0700 |
|---|---|---|
| committer | David Sterba <dsterba@suse.cz> | 2014-08-22 14:39:32 +0200 |
| commit | c2429c8a0d34ab47e69c8e66803ad4112ff31985 (patch) | |
| tree | 56fd93eb10b4de01d0294d21297ab0f321fdef63 /btrfs-image.c | |
| parent | 85691ebeac9432b4ebb1a268514279a0b2c7c61d (diff) | |
btrfs-image: Fix a data race in build_chunk_tree.
A mdrestore_struct was being written to without its mutex being held.
This race was found with ThreadSanitizer; the relevant part of the report
looks like this:
WARNING: ThreadSanitizer: data race (pid=18828)
Write of size 8 at 0x7fffffc3d088 by main thread:
#0 build_chunk_tree .../btrfs-progs/btrfs-image.c:2233
#1 __restore_metadump .../btrfs-progs/btrfs-image.c:2294
#2 restore_metadump .../btrfs-progs/btrfs-image.c:2345
#3 main .../btrfs-progs/btrfs-image.c:2545
Previous read of size 8 at 0x7fffffc3d088 by thread T1 (mutexes: write M0):
#0 restore_worker .../btrfs-progs/btrfs-image.c:1636
Location is stack of main thread.
Mutex M0 created at:
#0 pthread_mutex_init ??:0
#1 mdrestore_init .../btrfs-progs/btrfs-image.c:1766
#2 __restore_metadump .../btrfs-progs/btrfs-image.c:2286
#3 restore_metadump .../btrfs-progs/btrfs-image.c:2345
#4 main .../btrfs-progs/btrfs-image.c:2545
Thread T1 (tid=18830, running) created by main thread at:
#0 pthread_create ??:0
#1 mdrestore_init .../btrfs-progs/btrfs-image.c:1784
#2 __restore_metadump .../btrfs-progs/btrfs-image.c:2286
#3 restore_metadump .../btrfs-progs/btrfs-image.c:2345
#4 main .../btrfs-progs/btrfs-image.c:2545
Signed-off-by: Adam Buchbinder <abuchbinder@google.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Diffstat (limited to 'btrfs-image.c')
| -rw-r--r-- | btrfs-image.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/btrfs-image.c b/btrfs-image.c index 4c31e28c..cf1fe2d9 100644 --- a/btrfs-image.c +++ b/btrfs-image.c @@ -2216,6 +2216,7 @@ static int build_chunk_tree(struct mdrestore_struct *mdres, buffer = tmp; } + pthread_mutex_lock(&mdres->mutex); super = (struct btrfs_super_block *)buffer; chunk_root_bytenr = btrfs_super_chunk_root(super); mdres->leafsize = btrfs_super_leafsize(super); @@ -2224,6 +2225,7 @@ static int build_chunk_tree(struct mdrestore_struct *mdres, BTRFS_UUID_SIZE); mdres->devid = le64_to_cpu(super->dev_item.devid); free(buffer); + pthread_mutex_unlock(&mdres->mutex); return search_for_chunk_blocks(mdres, chunk_root_bytenr, 0); } |