[PATCH 3/3] ext4: pass in DIO_SKIP_DIO_COUNT to do_blockdev_direct_IO()

From: Jens Axboe
Date: Wed Apr 15 2015 - 18:02:06 EST


For writes, ext4_ext_direct_IO() already holds the inode i_dio_count
elevated, so we don't need the extra inc/dec that is done in
do_blockdev_direct_IO(). Pass in DIO_SKIP_DIO_COUNT to tell it that.

Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxx>
---
fs/ext4/inode.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 62d4615aa9b0..2605355791a3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2977,8 +2977,10 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
* conversion. This also disallows race between truncate() and
* overwrite DIO as i_dio_count needs to be incremented under i_mutex.
*/
- if (rw == WRITE)
+ if (rw == WRITE) {
inode_dio_inc(inode);
+ dio_flags |= DIO_SKIP_DIO_COUNT;
+ }

/* If we do a overwrite dio, i_mutex locking can be released */
overwrite = *((int *)iocb->private);
@@ -3032,7 +3034,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
get_block_func = ext4_get_block_write_nolock;
} else {
get_block_func = ext4_get_block_write;
- dio_flags = DIO_LOCKING;
+ dio_flags |= DIO_LOCKING;
}
if (IS_DAX(inode))
ret = dax_do_io(rw, iocb, inode, iter, offset, get_block_func,
--
1.9.1

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