From 02afc27faec94c9e068517a22acf55400976c698 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 4 Sep 2013 15:04:40 +0200 Subject: [PATCH] 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 with updates from Jeff Moyer and Darrick J. Wong . Signed-off-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Al Viro --- fs/block_dev.c | 2 +- fs/btrfs/file.c | 2 +- fs/cifs/file.c | 2 +- fs/direct-io.c | 45 ++++++++++++++++++++++++++++++++++++--------- fs/ext4/file.c | 2 +- mm/filemap.c | 2 +- 6 files changed, 41 insertions(+), 14 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index c7bda5c..1173a4e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -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); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 8e686a4..4d2eb64 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -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; diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 7e36ae3..9d0dd95 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -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); diff --git a/fs/direct-io.c b/fs/direct-io.c index 8b31b9f..1782023 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -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; @@ -1183,11 +1193,6 @@ 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 * even for AIO, we need to wait for i/o to complete before @@ -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; diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 319c9d2..3da2194 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -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); diff --git a/mm/filemap.c b/mm/filemap.c index 4b51ac1..731a2c2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -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); -- 2.7.4