Some late-breaking dentry handling fixes from Al and Jeff, a patch to

further restrict copy_file_range() to avoid potential data corruption
 from Luis and a fix for !CONFIG_CEPH_FSCACHE kernels.  Everything but
 the fscache fix is marked for stable.
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Merge tag 'ceph-for-5.4-rc7' of git://github.com/ceph/ceph-client

Pull ceph fixes from Ilya Dryomov:
 "Some late-breaking dentry handling fixes from Al and Jeff, a patch to
  further restrict copy_file_range() to avoid potential data corruption
  from Luis and a fix for !CONFIG_CEPH_FSCACHE kernels.

  Everything but the fscache fix is marked for stable"

* tag 'ceph-for-5.4-rc7' of git://github.com/ceph/ceph-client:
  ceph: return -EINVAL if given fsc mount option on kernel w/o support
  ceph: don't allow copy_file_range when stripe_count != 1
  ceph: don't try to handle hashed dentries in non-O_CREAT atomic_open
  ceph: add missing check in d_revalidate snapdir handling
  ceph: fix RCU case handling in ceph_d_revalidate()
  ceph: fix use-after-free in __ceph_remove_cap()

fs/ceph/caps.c

@@ -1058,6 +1058,11 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release)
 
 	dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
 
+	/* remove from inode's cap rbtree, and clear auth cap */
+	rb_erase(&cap->ci_node, &ci->i_caps);
+	if (ci->i_auth_cap == cap)
+		ci->i_auth_cap = NULL;
+
 	/* remove from session list */
 	spin_lock(&session->s_cap_lock);
 	if (session->s_cap_iterator == cap) {
@@ -1091,11 +1096,6 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release)
 
 	spin_unlock(&session->s_cap_lock);
 
-	/* remove from inode list */
-	rb_erase(&cap->ci_node, &ci->i_caps);
-	if (ci->i_auth_cap == cap)
-		ci->i_auth_cap = NULL;
-
 	if (removed)
 		ceph_put_cap(mdsc, cap);
 

fs/ceph/dir.c

@@ -1553,36 +1553,37 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
 {
 	int valid = 0;
 	struct dentry *parent;
-	struct inode *dir;
+	struct inode *dir, *inode;
 
 	if (flags & LOOKUP_RCU) {
 		parent = READ_ONCE(dentry->d_parent);
 		dir = d_inode_rcu(parent);
 		if (!dir)
 			return -ECHILD;
+		inode = d_inode_rcu(dentry);
 	} else {
 		parent = dget_parent(dentry);
 		dir = d_inode(parent);
+		inode = d_inode(dentry);
 	}
 
 	dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
-	     dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
+	     dentry, inode, ceph_dentry(dentry)->offset);
 
 	/* always trust cached snapped dentries, snapdir dentry */
 	if (ceph_snap(dir) != CEPH_NOSNAP) {
 		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
-		     dentry, d_inode(dentry));
+		     dentry, inode);
 		valid = 1;
-	} else if (d_really_is_positive(dentry) &&
+	} else if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
-		   ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
 		valid = 1;
 	} else {
 		valid = dentry_lease_is_valid(dentry, flags);
 		if (valid == -ECHILD)
 			return valid;
 		if (valid || dir_lease_is_valid(dir, dentry)) {
-			if (d_really_is_positive(dentry))
+			if (inode)
-				valid = ceph_is_any_caps(d_inode(dentry));
+				valid = ceph_is_any_caps(inode);
 			else
 				valid = 1;
 		}

fs/ceph/file.c

@@ -462,6 +462,9 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 		err = ceph_security_init_secctx(dentry, mode, &as_ctx);
 		if (err < 0)
 			goto out_ctx;
+	} else if (!d_in_lookup(dentry)) {
+		/* If it's not being looked up, it's negative */
+		return -ENOENT;
 	}
 
 	/* do the open */
@@ -1956,10 +1959,18 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off,
 	if (ceph_test_mount_opt(src_fsc, NOCOPYFROM))
 		return -EOPNOTSUPP;
 
+	/*
+	 * Striped file layouts require that we copy partial objects, but the
+	 * OSD copy-from operation only supports full-object copies.  Limit
+	 * this to non-striped file layouts for now.
+	 */
 	if ((src_ci->i_layout.stripe_unit != dst_ci->i_layout.stripe_unit) ||
-	    (src_ci->i_layout.stripe_count != dst_ci->i_layout.stripe_count) ||
+	    (src_ci->i_layout.stripe_count != 1) ||
-	    (src_ci->i_layout.object_size != dst_ci->i_layout.object_size))
+	    (dst_ci->i_layout.stripe_count != 1) ||
+	    (src_ci->i_layout.object_size != dst_ci->i_layout.object_size)) {
+		dout("Invalid src/dst files layout\n");
 		return -EOPNOTSUPP;
+	}
 
 	if (len < src_ci->i_layout.object_size)
 		return -EOPNOTSUPP; /* no remote copy will be done */

fs/ceph/inode.c

@@ -1434,6 +1434,7 @@ retry_lookup:
 		dout(" final dn %p\n", dn);
 	} else if ((req->r_op == CEPH_MDS_OP_LOOKUPSNAP ||
 		    req->r_op == CEPH_MDS_OP_MKSNAP) &&
+	           test_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags) &&
 		   !test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
 		struct inode *dir = req->r_parent;
 

fs/ceph/super.c

@@ -268,6 +268,7 @@ static int parse_fsopt_token(char *c, void *private)
 		}
 		break;
 	case Opt_fscache_uniq:
+#ifdef CONFIG_CEPH_FSCACHE
 		kfree(fsopt->fscache_uniq);
 		fsopt->fscache_uniq = kstrndup(argstr[0].from,
 					       argstr[0].to-argstr[0].from,
@@ -276,7 +277,10 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
 		break;
-		/* misc */
+#else
+		pr_err("fscache support is disabled\n");
+		return -EINVAL;
+#endif
 	case Opt_wsize:
 		if (intval < (int)PAGE_SIZE || intval > CEPH_MAX_WRITE_SIZE)
 			return -EINVAL;
@@ -353,10 +357,15 @@ static int parse_fsopt_token(char *c, void *private)
 		fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
 		break;
 	case Opt_fscache:
+#ifdef CONFIG_CEPH_FSCACHE
 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
 		kfree(fsopt->fscache_uniq);
 		fsopt->fscache_uniq = NULL;
 		break;
+#else
+		pr_err("fscache support is disabled\n");
+		return -EINVAL;
+#endif
 	case Opt_nofscache:
 		fsopt->flags &= ~CEPH_MOUNT_OPT_FSCACHE;
 		kfree(fsopt->fscache_uniq);