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author | David Sterba <dsterba@suse.com> | 2015-02-16 19:36:47 +0100 |
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committer | David Sterba <dsterba@suse.com> | 2015-10-10 18:40:04 +0200 |
commit | a83342aa0c8f0ca90057d3837ae8d198186e5153 (patch) | |
tree | 723d60098638e0f048ae630399d2f77d0e1a0c9d /fs/btrfs/ordered-data.c | |
parent | 33a9eca7e4a4c2c17aebbb11f0e506a48ebc30c9 (diff) | |
download | linux-a83342aa0c8f0ca90057d3837ae8d198186e5153.tar.gz linux-a83342aa0c8f0ca90057d3837ae8d198186e5153.tar.bz2 linux-a83342aa0c8f0ca90057d3837ae8d198186e5153.zip |
btrfs: add comments to barriers before waitqueue_active
Reduce number of undocumented barriers out there.
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/ordered-data.c')
-rw-r--r-- | fs/btrfs/ordered-data.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index 52170cf1757e..071005f008c1 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -345,6 +345,9 @@ int btrfs_dec_test_first_ordered_pending(struct inode *inode, if (entry->bytes_left == 0) { ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); + /* + * Implicit memory barrier after test_and_set_bit + */ if (waitqueue_active(&entry->wait)) wake_up(&entry->wait); } else { @@ -409,6 +412,9 @@ have_entry: if (entry->bytes_left == 0) { ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); + /* + * Implicit memory barrier after test_and_set_bit + */ if (waitqueue_active(&entry->wait)) wake_up(&entry->wait); } else { |