| Message ID | 1365456754-29373-25-git-send-email-jack@suse.cz |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Mon, Apr 08, 2013 at 11:32:29PM +0200, Jan Kara wrote: > 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_ext_truncate() anymore. > > Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Regards, - Zheng > --- > fs/ext4/extents.c | 6 ------ > fs/ext4/page-io.c | 9 ++++++++- > 2 files changed, 8 insertions(+), 7 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index ae22735..ca4ff71 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -4256,12 +4256,6 @@ void ext4_ext_truncate(struct inode *inode) > int err = 0; > > /* > - * finish any pending end_io work so we won't run the risk of > - * converting any truncated blocks to initialized later > - */ > - ext4_flush_unwritten_io(inode); > - > - /* > * probably first extent we're gonna free will be last in block > */ > err = ext4_writepage_trans_blocks(inode); > diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c > index 2967794..2f0b943 100644 > --- a/fs/ext4/page-io.c > +++ b/fs/ext4/page-io.c > @@ -145,7 +145,14 @@ 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; > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index ae22735..ca4ff71 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4256,12 +4256,6 @@ void ext4_ext_truncate(struct inode *inode) int err = 0; /* - * finish any pending end_io work so we won't run the risk of - * converting any truncated blocks to initialized later - */ - ext4_flush_unwritten_io(inode); - - /* * probably first extent we're gonna free will be last in block */ err = ext4_writepage_trans_blocks(inode); diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 2967794..2f0b943 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -145,7 +145,14 @@ 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;
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_ext_truncate() anymore. Signed-off-by: Jan Kara <jack@suse.cz> --- fs/ext4/extents.c | 6 ------ fs/ext4/page-io.c | 9 ++++++++- 2 files changed, 8 insertions(+), 7 deletions(-)