• Darrick J. Wong's avatar
    ocfs2: improve fsync efficiency and fix deadlock between aio_write and sync_file · 2931cdcb
    Darrick J. Wong authored
    Currently, ocfs2_sync_file grabs i_mutex and forces the current journal
    transaction to complete.  This isn't terribly efficient, since sync_file
    really only needs to wait for the last transaction involving that inode
    to complete, and this doesn't require i_mutex.
    
    Therefore, implement the necessary bits to track the newest tid
    associated with an inode, and teach sync_file to wait for that instead
    of waiting for everything in the journal to commit.  Furthermore, only
    issue the flush request to the drive if jbd2 hasn't already done so.
    
    This also eliminates the deadlock between ocfs2_file_aio_write() and
    ocfs2_sync_file().  aio_write takes i_mutex then calls
    ocfs2_aiodio_wait() to wait for unaligned dio writes to finish.
    However, if that dio completion involves calling fsync, then we can get
    into trouble when some ocfs2_sync_file tries to take i_mutex.
    Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
    Cc: Joel Becker <jlbec@evilplan.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    2931cdcb
namei.c 61.1 KB