ceph: voluntarily drop Xx caps for requests those touch parent mtime

For write requests the parent's mtime will be updated correspondingly.
And if the 'Xx' caps is issued and when releasing other caps together
with the write requests the MDS Locker will try to eval the xattr lock,
which need to change the locker state excl --> sync and need to do Xx
caps revocation.

Just voluntarily dropping CEPH_CAP_XATTR_EXCL caps to avoid a cap
revoke message, which could cause the mtime will be overwrote by stale
one.

[ idryomov: break unnecessarily long lines ]

Link: https://tracker.ceph.com/issues/61584Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/dir.c

@@ -886,7 +886,8 @@ static int ceph_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 	req->r_args.mknod.mode = cpu_to_le32(mode);
 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
-	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
+			     CEPH_CAP_XATTR_EXCL;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	if (as_ctx.pagelist) {
 		req->r_pagelist = as_ctx.pagelist;
@@ -953,7 +954,8 @@ static int ceph_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 	req->r_dentry = dget(dentry);
 	req->r_num_caps = 2;
-	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
+			     CEPH_CAP_XATTR_EXCL;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	if (as_ctx.pagelist) {
 		req->r_pagelist = as_ctx.pagelist;
@@ -1022,7 +1024,8 @@ static int ceph_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	ihold(dir);
 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 	req->r_args.mkdir.mode = cpu_to_le32(mode);
-	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
+			     CEPH_CAP_XATTR_EXCL;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	if (as_ctx.pagelist) {
 		req->r_pagelist = as_ctx.pagelist;
@@ -1079,7 +1082,7 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 	req->r_parent = dir;
 	ihold(dir);
 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
-	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	/* release LINK_SHARED on source inode (mds will lock it) */
 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
@@ -1218,7 +1221,7 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	req->r_num_caps = 2;
 	req->r_parent = dir;
 	ihold(dir);
-	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
 
@@ -1320,9 +1323,9 @@ static int ceph_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 	req->r_parent = new_dir;
 	ihold(new_dir);
 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
-	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
-	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	/* release LINK_RDCACHE on source inode (mds will lock it) */
 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;

fs/ceph/file.c

@@ -791,7 +791,8 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 	if (flags & O_CREAT) {
 		struct ceph_file_layout lo;
 
-		req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+		req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
+				     CEPH_CAP_XATTR_EXCL;
 		req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 		if (as_ctx.pagelist) {
 			req->r_pagelist = as_ctx.pagelist;