On Wed, 2021-12-08 at 20:45 +0800, xiubli@xxxxxxxxxx wrote:
> From: Xiubo Li <xiubli@xxxxxxxxxx>
>
> Always return the last object's version.
>
> Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
> ---
> fs/ceph/file.c | 8 ++++++--
> fs/ceph/super.h | 3 ++-
> 2 files changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index b42158c9aa16..9279b8642add 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -883,7 +883,8 @@ enum {
> * only return a short read to the caller if we hit EOF.
> */
> ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
> - struct iov_iter *to, int *retry_op)
> + struct iov_iter *to, int *retry_op,
> + u64 *last_objver)
> {
> struct ceph_inode_info *ci = ceph_inode(inode);
> struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
> @@ -950,6 +951,9 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
> req->r_end_latency,
> len, ret);
>
> + if (last_objver)
> + *last_objver = req->r_version;
> +
Much better! That said, this might be unreliable if (say) the first OSD
read was successful and then the second one failed on a long read that
spans objects. We'd want to return a short read in that case, but the
last_objver would end up being set to 0.
I think you shouldn't set last_objver unless the call is going to return
>0, and then you want to set it to the object version of the last
successful read in the series.
> ceph_osdc_put_request(req);
>
> i_size = i_size_read(inode);
> @@ -1020,7 +1024,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
> (unsigned)iov_iter_count(to),
> (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
>
> - return __ceph_sync_read(inode, &iocb->ki_pos, to, retry_op);
> + return __ceph_sync_read(inode, &iocb->ki_pos, to, retry_op, NULL);
> }
>
> struct ceph_aio_request {
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 84fec46308b0..a7bdb28af595 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -1258,7 +1258,8 @@ extern int ceph_open(struct inode *inode, struct file *file);
> extern int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
> struct file *file, unsigned flags, umode_t mode);
> extern ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
> - struct iov_iter *to, int *retry_op);
> + struct iov_iter *to, int *retry_op,
> + u64 *last_objver);
> extern int ceph_release(struct inode *inode, struct file *filp);
> extern void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
> char *data, size_t len);
--
Jeff Layton <jlayton@xxxxxxxxxx>
