Maxim Patlasov <mpatla...@virtuozzo.com> writes:
> For ext4 dio_fsync() is actually equivalent to direct call to fsync fop:
>
> 1) file->f_op cannot be NULL;
> 2) file->f_op->fsync is always equal to ext4_sync_file;
> 3) ext4_sync_file() does filemap_write_and_wait() internally,
> no need to call it explicitly.
>
> The patch also fixes a potential problem: if fsync() fails, it's better
> to pass error code up to the stack of callers.
>
> Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com>
Acked-by:dmonak...@openvz.org
> ---
> drivers/block/ploop/io_direct.c | 52
> ++++++++++++++++++---------------------
> 1 file changed, 24 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/block/ploop/io_direct.c b/drivers/block/ploop/io_direct.c
> index a37f296..1ff848c 100644
> --- a/drivers/block/ploop/io_direct.c
> +++ b/drivers/block/ploop/io_direct.c
> @@ -844,21 +844,6 @@ static int dio_fsync_thread(void * data)
> return 0;
> }
>
> -static int dio_fsync(struct file * file)
> -{
> - int err, ret;
> - struct address_space *mapping = file->f_mapping;
> -
> - ret = filemap_write_and_wait(mapping);
> - err = 0;
> - if (file->f_op && file->f_op->fsync) {
> - err = file->f_op->fsync(file, 0, LLONG_MAX, 0);
> - if (!ret)
> - ret = err;
> - }
> - return ret;
> -}
> -
> /* Invalidate page cache. It is called with inode mutex taken
> * and mapping mapping must be synced. If some dirty pages remained,
> * it will fail.
> @@ -949,20 +934,17 @@ static void dio_destroy(struct ploop_io * io)
> static int dio_sync(struct ploop_io * io)
> {
> struct file * file = io->files.file;
> + int err = 0;
>
> if (file)
> - dio_fsync(file);
> - return 0;
> + err = file->f_op->fsync(file, 0, LLONG_MAX, 0);
> +
> + return err;
> }
>
> static int dio_stop(struct ploop_io * io)
> {
> - struct file * file = io->files.file;
> -
> - if (file) {
> - dio_fsync(file);
> - }
> - return 0;
> + return io->ops->sync(io);
> }
>
> static int dio_open(struct ploop_io * io)
> @@ -979,7 +961,9 @@ static int dio_open(struct ploop_io * io)
> io->files.inode = io->files.mapping->host;
> io->files.bdev = io->files.inode->i_sb->s_bdev;
>
> - dio_fsync(file);
> + err = io->ops->sync(io);
> + if (err)
> + return err;
>
> mutex_lock(&io->files.inode->i_mutex);
> em_tree = ploop_dio_open(io, (delta->flags & PLOOP_FMT_RDONLY));
> @@ -1646,7 +1630,11 @@ static int dio_prepare_snapshot(struct ploop_io * io,
> struct ploop_snapdata *sd)
> return -EINVAL;
> }
>
> - dio_fsync(file);
> + err = io->ops->sync(io);
> + if (err) {
> + fput(file);
> + return err;
> + }
>
> mutex_lock(&io->files.inode->i_mutex);
> err = dio_invalidate_cache(io->files.mapping, io->files.bdev);
> @@ -1713,7 +1701,11 @@ static int dio_prepare_merge(struct ploop_io * io,
> struct ploop_snapdata *sd)
> return -EINVAL;
> }
>
> - dio_fsync(file);
> + err = io->ops->sync(io);
> + if (err) {
> + fput(file);
> + return err;
> + }
>
> mutex_lock(&io->files.inode->i_mutex);
>
> @@ -1772,8 +1764,12 @@ static int dio_truncate(struct ploop_io * io, struct
> file * file,
> atomic_long_sub(*io->size_ptr - new_size, &ploop_io_images_size);
> *io->size_ptr = new_size;
>
> - if (!err)
> - err = dio_fsync(file);
> + if (!err) {
> + if (io->files.file == file)
> + err = io->ops->sync(io);
> + else
> + err = file->f_op->fsync(file, 0, LLONG_MAX, 0);
> + }
>
> return err;
> }
signature.asc
Description: PGP signature
_______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
