direct-io: Handle O_(D)SYNC AIO

Call generic_write_sync() from the deferred I/O completion handler if
O_DSYNC is set for a write request.  Also make sure various callers
don't call generic_write_sync if the direct I/O code returns
-EIOCBQUEUED.

Based on an earlier patch from Jan Kara <jack@suse.cz> with updates from
Jeff Moyer <jmoyer@redhat.com> and Darrick J. Wong <darrick.wong@oracle.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2013-09-04 15:04:40 +02:00 committed by Al Viro
parent 7b7a8665ed
commit 02afc27fae
6 changed files with 41 additions and 14 deletions

View File

@ -1519,7 +1519,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
blk_start_plug(&plug);
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
if (ret > 0 || ret == -EIOCBQUEUED) {
if (ret > 0) {
ssize_t err;
err = generic_write_sync(file, pos, ret);

View File

@ -1727,7 +1727,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
*/
BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
BTRFS_I(inode)->last_sub_trans = root->log_transid;
if (num_written > 0 || num_written == -EIOCBQUEUED) {
if (num_written > 0) {
err = generic_write_sync(file, pos, num_written);
if (err < 0 && num_written > 0)
num_written = err;

View File

@ -2553,7 +2553,7 @@ cifs_writev(struct kiocb *iocb, const struct iovec *iov,
mutex_unlock(&inode->i_mutex);
}
if (rc > 0 || rc == -EIOCBQUEUED) {
if (rc > 0) {
ssize_t err;
err = generic_write_sync(file, pos, rc);

View File

@ -266,8 +266,18 @@ static ssize_t dio_complete(struct dio *dio, loff_t offset, ssize_t ret,
dio->end_io(dio->iocb, offset, transferred, dio->private);
inode_dio_done(dio->inode);
if (is_async)
if (is_async) {
if (dio->rw & WRITE) {
int err;
err = generic_write_sync(dio->iocb->ki_filp, offset,
transferred);
if (err < 0 && ret > 0)
ret = err;
}
aio_complete(dio->iocb, ret, 0);
}
kmem_cache_free(dio_cache, dio);
return ret;
@ -1182,11 +1192,6 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
}
}
/*
* Will be decremented at I/O completion time.
*/
atomic_inc(&inode->i_dio_count);
/*
* For file extending writes updating i_size before data
* writeouts complete can expose uninitialized blocks. So
@ -1195,11 +1200,33 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
*/
dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) &&
(end > i_size_read(inode)));
retval = 0;
dio->inode = inode;
dio->rw = rw;
/*
* For AIO O_(D)SYNC writes we need to defer completions to a workqueue
* so that we can call ->fsync.
*/
if (dio->is_async && (rw & WRITE) &&
((iocb->ki_filp->f_flags & O_DSYNC) ||
IS_SYNC(iocb->ki_filp->f_mapping->host))) {
retval = dio_set_defer_completion(dio);
if (retval) {
/*
* We grab i_mutex only for reads so we don't have
* to release it here
*/
kmem_cache_free(dio_cache, dio);
goto out;
}
}
/*
* Will be decremented at I/O completion time.
*/
atomic_inc(&inode->i_dio_count);
retval = 0;
sdio.blkbits = blkbits;
sdio.blkfactor = i_blkbits - blkbits;
sdio.block_in_file = offset >> blkbits;

View File

@ -149,7 +149,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
if (ret > 0 || ret == -EIOCBQUEUED) {
if (ret > 0) {
ssize_t err;
err = generic_write_sync(file, pos, ret);

View File

@ -2550,7 +2550,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
if (ret > 0 || ret == -EIOCBQUEUED) {
if (ret > 0) {
ssize_t err;
err = generic_write_sync(file, pos, ret);