[RFC PATCH v11 38/51] ceph: add object version support for sync read

[Jeff Layton <jlayton@kernel.org>]

From: Xiubo Li <xiubli@redhat.com>

Always return the last object's version.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/file.c  | 12 ++++++++++--
 fs/ceph/super.h |  3 ++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 0e91ae995f78..1985e3102533 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -924,7 +924,8 @@ 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);
@@ -934,6 +935,7 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
 	u64 len = iov_iter_count(to);
 	u64 i_size = i_size_read(inode);
 	bool sparse = ceph_test_mount_opt(fsc, SPARSEREAD);
+	u64 objver = 0;
 
 	dout("sync_read on inode %p %llx~%llx\n", inode, *ki_pos, len);
 
@@ -1004,6 +1006,9 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
 					 req->r_end_latency,
 					 len, ret);
 
+		if (ret > 0)
+			objver = req->r_version;
+
 		i_size = i_size_read(inode);
 		dout("sync_read %llu~%llu got %zd i_size %llu%s\n",
 		     off, len, ret, i_size, (more ? " MORE" : ""));
@@ -1065,6 +1070,9 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
 		}
 	}
 
+	if (last_objver && ret > 0)
+		*last_objver = objver;
+
 	dout("sync_read result %zd retry_op %d\n", ret, *retry_op);
 	return ret;
 }
@@ -1078,7 +1086,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
 	dout("sync_read on file %p %llx~%zx %s\n", file, iocb->ki_pos,
 	     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 339284e90cb3..e3d63b727e52 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1267,7 +1267,8 @@ 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);
-- 
2.35.1