ceph: use getattr request to fetch inline data

Add a new parameter 'locked_page' to ceph_do_getattr(). If inline data
in getattr reply will be copied to the page.
Signed-off-by: Yan, Zheng <zyan@redhat.com>

fs/ceph/inode.c

@@ -659,7 +659,7 @@ void ceph_fill_file_time(struct inode *inode, int issued,
  * Populate an inode based on info from mds.  May be called on new or
  * existing inodes.
  */
-static int fill_inode(struct inode *inode,
+static int fill_inode(struct inode *inode, struct page *locked_page,
 		      struct ceph_mds_reply_info_in *iinfo,
 		      struct ceph_mds_reply_dirfrag *dirinfo,
 		      struct ceph_mds_session *session,
@@ -883,14 +883,15 @@ static int fill_inode(struct inode *inode,
 		int cache_caps = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
 		ci->i_inline_version = iinfo->inline_version;
 		if (ci->i_inline_version != CEPH_INLINE_NONE &&
-		    (le32_to_cpu(info->cap.caps) & cache_caps))
+		    (locked_page ||
+		     (le32_to_cpu(info->cap.caps) & cache_caps)))
 			fill_inline = true;
 	}
 
 	spin_unlock(&ci->i_ceph_lock);
 
 	if (fill_inline)
-		ceph_fill_inline_data(inode, NULL,
+		ceph_fill_inline_data(inode, locked_page,
 				      iinfo->inline_data, iinfo->inline_len);
 
 	if (wake)
@@ -1080,7 +1081,8 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 		struct inode *dir = req->r_locked_dir;
 
 		if (dir) {
-			err = fill_inode(dir, &rinfo->diri, rinfo->dirfrag,
+			err = fill_inode(dir, NULL,
+					 &rinfo->diri, rinfo->dirfrag,
 					 session, req->r_request_started, -1,
 					 &req->r_caps_reservation);
 			if (err < 0)
@@ -1150,7 +1152,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 		}
 		req->r_target_inode = in;
 
-		err = fill_inode(in, &rinfo->targeti, NULL,
+		err = fill_inode(in, req->r_locked_page, &rinfo->targeti, NULL,
 				session, req->r_request_started,
 				(!req->r_aborted && rinfo->head->result == 0) ?
 				req->r_fmode : -1,
@@ -1321,7 +1323,7 @@ static int readdir_prepopulate_inodes_only(struct ceph_mds_request *req,
 			dout("new_inode badness got %d\n", err);
 			continue;
 		}
-		rc = fill_inode(in, &rinfo->dir_in[i], NULL, session,
+		rc = fill_inode(in, NULL, &rinfo->dir_in[i], NULL, session,
 				req->r_request_started, -1,
 				&req->r_caps_reservation);
 		if (rc < 0) {
@@ -1437,7 +1439,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
 			}
 		}
 
-		if (fill_inode(in, &rinfo->dir_in[i], NULL, session,
+		if (fill_inode(in, NULL, &rinfo->dir_in[i], NULL, session,
 			       req->r_request_started, -1,
 			       &req->r_caps_reservation) < 0) {
 			pr_err("fill_inode badness on %p\n", in);
@@ -1920,7 +1922,8 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
  * Verify that we have a lease on the given mask.  If not,
  * do a getattr against an mds.
  */
-int ceph_do_getattr(struct inode *inode, int mask, bool force)
+int __ceph_do_getattr(struct inode *inode, struct page *locked_page,
+		      int mask, bool force)
 {
 	struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
 	struct ceph_mds_client *mdsc = fsc->mdsc;
@@ -1932,7 +1935,8 @@ int ceph_do_getattr(struct inode *inode, int mask, bool force)
 		return 0;
 	}
 
-	dout("do_getattr inode %p mask %s mode 0%o\n", inode, ceph_cap_string(mask), inode->i_mode);
+	dout("do_getattr inode %p mask %s mode 0%o\n",
+	     inode, ceph_cap_string(mask), inode->i_mode);
 	if (!force && ceph_caps_issued_mask(ceph_inode(inode), mask, 1))
 		return 0;
 
@@ -1943,7 +1947,19 @@ int ceph_do_getattr(struct inode *inode, int mask, bool force)
 	ihold(inode);
 	req->r_num_caps = 1;
 	req->r_args.getattr.mask = cpu_to_le32(mask);
+	req->r_locked_page = locked_page;
 	err = ceph_mdsc_do_request(mdsc, NULL, req);
+	if (locked_page && err == 0) {
+		u64 inline_version = req->r_reply_info.targeti.inline_version;
+		if (inline_version == 0) {
+			/* the reply is supposed to contain inline data */
+			err = -EINVAL;
+		} else if (inline_version == CEPH_INLINE_NONE) {
+			err = -ENODATA;
+		} else {
+			err = req->r_reply_info.targeti.inline_len;
+		}
+	}
 	ceph_mdsc_put_request(req);
 	dout("do_getattr result=%d\n", err);
 	return err;

fs/ceph/mds_client.h

@@ -223,6 +223,7 @@ struct ceph_mds_request {
 	int r_request_release_offset;
 	struct ceph_msg  *r_reply;
 	struct ceph_mds_reply_info_parsed r_reply_info;
+	struct page *r_locked_page;
 	int r_err;
 	bool r_aborted;
 

fs/ceph/super.h

@@ -744,7 +744,12 @@ extern void ceph_queue_vmtruncate(struct inode *inode);
 extern void ceph_queue_invalidate(struct inode *inode);
 extern void ceph_queue_writeback(struct inode *inode);
 
-extern int ceph_do_getattr(struct inode *inode, int mask, bool force);
+extern int __ceph_do_getattr(struct inode *inode, struct page *locked_page,
+			     int mask, bool force);
+static inline int ceph_do_getattr(struct inode *inode, int mask, bool force)
+{
+	return __ceph_do_getattr(inode, NULL, mask, force);
+}
 extern int ceph_permission(struct inode *inode, int mask);
 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
 extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,

include/linux/ceph/ceph_fs.h

@@ -617,6 +617,8 @@ int ceph_flags_to_mode(int flags);
 				 CEPH_CAP_LINK_SHARED |	\
 				 CEPH_CAP_FILE_SHARED |	\
 				 CEPH_CAP_XATTR_SHARED)
+#define CEPH_STAT_CAP_INLINE_DATA (CEPH_CAP_FILE_SHARED | \
+				   CEPH_CAP_FILE_RD)
 
 #define CEPH_CAP_ANY_SHARED (CEPH_CAP_AUTH_SHARED |			\
 			      CEPH_CAP_LINK_SHARED |			\