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| author | Wengang Wang <wen.gang.wang@oracle.com> | 2014-04-03 14:46:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-03 16:20:53 -0700 |
| commit | c18ceab01240fd4c354b78d877571b729908e4a3 (patch) | |
| tree | d9c0107c30019e3299fe1b712d2eebaf832e55ed /fs/ocfs2/file.c | |
| parent | 181a9a043b5424f2e6451297bbc27b196fe88475 (diff) | |
| download | linux-c18ceab01240fd4c354b78d877571b729908e4a3.tar.gz | |
ocfs2: change ip_unaligned_aio to of type mutex from atomit_t
There is a problem that waitqueue_active() may check stale data thus miss a wakeup of threads waiting on ip_unaligned_aio. The valid value of ip_unaligned_aio is only 0 and 1 so we can change it to be of type mutex thus the above prolem is avoid. Another benifit is that mutex which works as FIFO is fairer than wake_up_all(). Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/file.c')
| -rw-r--r-- | fs/ocfs2/file.c | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 51632c40e896..1673438789fe 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2061,13 +2061,6 @@ out: return ret; } -static void ocfs2_aiodio_wait(struct inode *inode) -{ - wait_queue_head_t *wq = ocfs2_ioend_wq(inode); - - wait_event(*wq, (atomic_read(&OCFS2_I(inode)->ip_unaligned_aio) == 0)); -} - static int ocfs2_is_io_unaligned(struct inode *inode, size_t count, loff_t pos) { int blockmask = inode->i_sb->s_blocksize - 1; @@ -2345,10 +2338,8 @@ relock: * Wait on previous unaligned aio to complete before * proceeding. */ - ocfs2_aiodio_wait(inode); - - /* Mark the iocb as needing a decrement in ocfs2_dio_end_io */ - atomic_inc(&OCFS2_I(inode)->ip_unaligned_aio); + mutex_lock(&OCFS2_I(inode)->ip_unaligned_aio); + /* Mark the iocb as needing an unlock in ocfs2_dio_end_io */ ocfs2_iocb_set_unaligned_aio(iocb); } @@ -2428,7 +2419,7 @@ out_dio: if (unaligned_dio) { ocfs2_iocb_clear_unaligned_aio(iocb); - atomic_dec(&OCFS2_I(inode)->ip_unaligned_aio); + mutex_unlock(&OCFS2_I(inode)->ip_unaligned_aio); } out: |