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| author | Jan Kara <jack@suse.cz> | 2013-06-04 22:30:00 +0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-06-04 22:30:00 +0400 |
| commit | a115f749c14ee94e8b7bdbd203a5afdb1659156b (patch) | |
| tree | 6977574e331f21d2fae2247e442a1f8f23560203 /fs/ext4/page-io.c | |
| parent | e83403959fddb6d90e8c5e54bbce3110d0c82165 (diff) | |
| download | linux-a115f749c14ee94e8b7bdbd203a5afdb1659156b.tar.xz | |
ext4: remove wait for unwritten extent conversion from ext4_truncate()
Since PageWriteback bit is now cleared after extents are converted
from unwritten to written ones, we have full exclusion of writeback
path from truncate (truncate_inode_pages() waits for PageWriteback
bits to get cleared on all invalidated pages). Exclusion from DIO
path is achieved by inode_dio_wait() call in ext4_setattr(). So
there's no need to wait for extent convertion in ext4_truncate()
anymore.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/page-io.c')
| -rw-r--r-- | fs/ext4/page-io.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 755741c211a4..0f65561ab5a5 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -158,7 +158,14 @@ static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) wake_up_all(ext4_ioend_wq(inode)); } -/* check a range of space and convert unwritten extents to written. */ +/* + * Check a range of space and convert unwritten extents to written. Note that + * we are protected from truncate touching same part of extent tree by the + * fact that truncate code waits for all DIO to finish (thus exclusion from + * direct IO is achieved) and also waits for PageWriteback bits. Thus we + * cannot get to ext4_ext_truncate() before all IOs overlapping that range are + * completed (happens from ext4_free_ioend()). + */ static int ext4_end_io(ext4_io_end_t *io) { struct inode *inode = io->inode; |