diff options
author | Chris Mason <clm@fb.com> | 2015-10-12 16:24:40 -0700 |
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committer | Chris Mason <clm@fb.com> | 2015-10-12 16:24:40 -0700 |
commit | 6db4a7335dd701a0e20275440ee057d3db2a7ae3 (patch) | |
tree | c0734d7411806ef91bfeb615bf528ffb349938fe /fs/btrfs/tree-log.c | |
parent | 62fb50ab7c903357c92cef2f7677235b92ac575f (diff) | |
parent | ee86395458072760d62e66aad10a5e9e8902b8cf (diff) |
Merge branch 'fix/waitqueue-barriers' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r-- | fs/btrfs/tree-log.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c3f9a9c71f28..1fffe8845c09 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -229,7 +229,9 @@ int btrfs_pin_log_trans(struct btrfs_root *root) void btrfs_end_log_trans(struct btrfs_root *root) { if (atomic_dec_and_test(&root->log_writers)) { - smp_mb(); + /* + * Implicit memory barrier after atomic_dec_and_test + */ if (waitqueue_active(&root->log_writer_wait)) wake_up(&root->log_writer_wait); } @@ -2820,7 +2822,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, mutex_lock(&log_root_tree->log_mutex); if (atomic_dec_and_test(&log_root_tree->log_writers)) { - smp_mb(); + /* + * Implicit memory barrier after atomic_dec_and_test + */ if (waitqueue_active(&log_root_tree->log_writer_wait)) wake_up(&log_root_tree->log_writer_wait); } @@ -2950,6 +2954,9 @@ out_wake_log_root: atomic_set(&log_root_tree->log_commit[index2], 0); mutex_unlock(&log_root_tree->log_mutex); + /* + * The barrier before waitqueue_active is implied by mutex_unlock + */ if (waitqueue_active(&log_root_tree->log_commit_wait[index2])) wake_up(&log_root_tree->log_commit_wait[index2]); out: @@ -2961,6 +2968,9 @@ out: atomic_set(&root->log_commit[index1], 0); mutex_unlock(&root->log_mutex); + /* + * The barrier before waitqueue_active is implied by mutex_unlock + */ if (waitqueue_active(&root->log_commit_wait[index1])) wake_up(&root->log_commit_wait[index1]); return ret; |