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Message-Id: <1365456754-29373-25-git-send-email-jack@suse.cz> Date: Mon, 8 Apr 2013 23:32:29 +0200 From: Jan Kara <jack@...e.cz> To: Ted Tso <tytso@....edu> Cc: linux-ext4@...r.kernel.org, Jan Kara <jack@...e.cz> Subject: [PATCH 24/29] ext4: Remove wait for unwritten extent conversion from ext4_ext_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_ext_truncate() anymore. Signed-off-by: Jan Kara <jack@...e.cz> --- 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@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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