ceph: always renew caps if mds_wanted is insufficient

Original code only renews caps for inodes with CEPH_I_CAP_DROPPED flag,
which indicates that mds has closed the session and caps were dropped.
Remove this flag in preparation for not requesting caps for idle open
files.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/caps.c

@@ -2686,6 +2686,7 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
 		}
 	} else {
 		int session_readonly = false;
+		int mds_wanted;
 		if (ci->i_auth_cap &&
 		    (need & (CEPH_CAP_FILE_WR | CEPH_CAP_FILE_EXCL))) {
 			struct ceph_mds_session *s = ci->i_auth_cap->session;
@@ -2694,32 +2695,27 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
 			spin_unlock(&s->s_cap_lock);
 		}
 		if (session_readonly) {
-			dout("get_cap_refs %p needed %s but mds%d readonly\n",
+			dout("get_cap_refs %p need %s but mds%d readonly\n",
 			     inode, ceph_cap_string(need), ci->i_auth_cap->mds);
 			ret = -EROFS;
 			goto out_unlock;
 		}
 
-		if (ci->i_ceph_flags & CEPH_I_CAP_DROPPED) {
-			int mds_wanted;
-			if (READ_ONCE(mdsc->fsc->mount_state) ==
-			    CEPH_MOUNT_SHUTDOWN) {
+		if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
 			dout("get_cap_refs %p forced umount\n", inode);
 			ret = -EIO;
 			goto out_unlock;
 		}
 		mds_wanted = __ceph_caps_mds_wanted(ci, false);
-			if (need & ~(mds_wanted & need)) {
-				dout("get_cap_refs %p caps were dropped"
-				     " (session killed?)\n", inode);
+		if (need & ~mds_wanted) {
+			dout("get_cap_refs %p need %s > mds_wanted %s\n",
+			     inode, ceph_cap_string(need),
+			     ceph_cap_string(mds_wanted));
 			ret = -ESTALE;
 			goto out_unlock;
 		}
-			if (!(file_wanted & ~mds_wanted))
-				ci->i_ceph_flags &= ~CEPH_I_CAP_DROPPED;
-		}
 
-		dout("get_cap_refs %p have %s needed %s\n", inode,
+		dout("get_cap_refs %p have %s need %s\n", inode,
 		     ceph_cap_string(have), ceph_cap_string(need));
 	}
 out_unlock:
@@ -3678,8 +3674,6 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 		goto out_unlock;
 
 	if (target < 0) {
-		if (cap->mds_wanted | cap->issued)
-			ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
 		__ceph_remove_cap(cap, false);
 		goto out_unlock;
 	}

fs/ceph/mds_client.c

@@ -1514,8 +1514,6 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
 	dout("removing cap %p, ci is %p, inode is %p\n",
 	     cap, ci, &ci->vfs_inode);
 	spin_lock(&ci->i_ceph_lock);
-	if (cap->mds_wanted | cap->issued)
-		ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
 	__ceph_remove_cap(cap, false);
 	if (!ci->i_auth_cap) {
 		struct ceph_cap_flush *cf;
@@ -1681,9 +1679,6 @@ static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
 			/* mds did not re-issue stale cap */
 			spin_lock(&ci->i_ceph_lock);
 			cap->issued = cap->implemented = CEPH_CAP_PIN;
-			/* make sure mds knows what we want */
-			if (__ceph_caps_file_wanted(ci) & ~cap->mds_wanted)
-				ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
 			spin_unlock(&ci->i_ceph_lock);
 		}
 	} else if (ev == FORCE_RO) {

fs/ceph/super.h

@@ -522,13 +522,12 @@ static inline struct inode *ceph_find_inode(struct super_block *sb,
 #define CEPH_I_POOL_RD		(1 << 4)  /* can read from pool */
 #define CEPH_I_POOL_WR		(1 << 5)  /* can write to pool */
 #define CEPH_I_SEC_INITED	(1 << 6)  /* security initialized */
-#define CEPH_I_CAP_DROPPED	(1 << 7)  /* caps were forcibly dropped */
-#define CEPH_I_KICK_FLUSH	(1 << 8)  /* kick flushing caps */
-#define CEPH_I_FLUSH_SNAPS	(1 << 9)  /* need flush snapss */
-#define CEPH_I_ERROR_WRITE	(1 << 10) /* have seen write errors */
-#define CEPH_I_ERROR_FILELOCK	(1 << 11) /* have seen file lock errors */
-#define CEPH_I_ODIRECT		(1 << 12) /* inode in direct I/O mode */
-#define CEPH_ASYNC_CREATE_BIT	(13)	  /* async create in flight for this */
+#define CEPH_I_KICK_FLUSH	(1 << 7)  /* kick flushing caps */
+#define CEPH_I_FLUSH_SNAPS	(1 << 8)  /* need flush snapss */
+#define CEPH_I_ERROR_WRITE	(1 << 9) /* have seen write errors */
+#define CEPH_I_ERROR_FILELOCK	(1 << 10) /* have seen file lock errors */
+#define CEPH_I_ODIRECT		(1 << 11) /* inode in direct I/O mode */
+#define CEPH_ASYNC_CREATE_BIT	(12)	  /* async create in flight for this */
 #define CEPH_I_ASYNC_CREATE	(1 << CEPH_ASYNC_CREATE_BIT)
 
 /*