Merging upstream version 6.10.3.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 433 insertions, 34 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index ee9caf7916..8c16bc5250 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -193,7 +193,7 @@ static void ceph_netfs_expand_readahead(struct netfs_io_request *rreq)
 	 * block, but do not exceed the file size, unless the original
 	 * request already exceeds it.
 	 */
-	new_end = min(round_up(end, lo->stripe_unit), rreq->i_size);
+	new_end = umin(round_up(end, lo->stripe_unit), rreq->i_size);
 	if (new_end > end && new_end <= rreq->start + max_len)
 		rreq->len = new_end - rreq->start;
 
@@ -498,11 +498,6 @@ const struct netfs_request_ops ceph_netfs_ops = {
 };
 
 #ifdef CONFIG_CEPH_FSCACHE
-static void ceph_set_page_fscache(struct page *page)
-{
-	set_page_fscache(page);
-}
-
 static void ceph_fscache_write_terminated(void *priv, ssize_t error, bool was_async)
 {
 	struct inode *inode = priv;
@@ -517,13 +512,9 @@ static void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, b
 	struct fscache_cookie *cookie = ceph_fscache_cookie(ci);
 
 	fscache_write_to_cache(cookie, inode->i_mapping, off, len, i_size_read(inode),
-			       ceph_fscache_write_terminated, inode, caching);
+			       ceph_fscache_write_terminated, inode, true, caching);
 }
 #else
-static inline void ceph_set_page_fscache(struct page *page)
-{
-}
-
 static inline void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, bool caching)
 {
 }
@@ -715,8 +706,6 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 		len = wlen;
 
 	set_page_writeback(page);
-	if (caching)
-		ceph_set_page_fscache(page);
 	ceph_fscache_write_to_cache(inode, page_off, len, caching);
 
 	if (IS_ENCRYPTED(inode)) {
@@ -800,8 +789,6 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 		return AOP_WRITEPAGE_ACTIVATE;
 	}
 
-	wait_on_page_fscache(page);
-
 	err = writepage_nounlock(page, wbc);
 	if (err == -ERESTARTSYS) {
 		/* direct memory reclaimer was killed by SIGKILL. return 0
@@ -1075,7 +1062,7 @@ get_more_pages:
 				unlock_page(page);
 				break;
 			}
-			if (PageWriteback(page) || PageFsCache(page)) {
+			if (PageWriteback(page)) {
 				if (wbc->sync_mode == WB_SYNC_NONE) {
 					doutc(cl, "%p under writeback\n", page);
 					unlock_page(page);
@@ -1083,7 +1070,6 @@ get_more_pages:
 				}
 				doutc(cl, "waiting on writeback %p\n", page);
 				wait_on_page_writeback(page);
-				wait_on_page_fscache(page);
 			}
 
 			if (!clear_page_dirty_for_io(page)) {
@@ -1268,8 +1254,6 @@ new_request:
 			}
 
 			set_page_writeback(page);
-			if (caching)
-				ceph_set_page_fscache(page);
 			len += thp_size(page);
 		}
 		ceph_fscache_write_to_cache(inode, offset, len, caching);
@@ -1513,7 +1497,7 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 	if (r < 0)
 		return r;
 
-	folio_wait_fscache(folio);
+	folio_wait_private_2(folio); /* [DEPRECATED] */
 	WARN_ON_ONCE(!folio_test_locked(folio));
 	*pagep = &folio->page;
 	return 0;
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 0e9f56eaba..82a2e2a06a 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1336,8 +1336,12 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	struct inode *inode = d_inode(dentry);
 	struct ceph_mds_request *req;
 	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
+	struct dentry *dn;
 	int err = -EROFS;
 	int op;
+	char *path;
+	int pathlen;
+	u64 pathbase;
 
 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
 		/* rmdir .snap/foo is RMSNAP */
@@ -1351,6 +1355,30 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
 	} else
 		goto out;
+
+	dn = d_find_alias(dir);
+	if (!dn) {
+		try_async = false;
+	} else {
+		path = ceph_mdsc_build_path(mdsc, dn, &pathlen, &pathbase, 0);
+		if (IS_ERR(path)) {
+			try_async = false;
+			err = 0;
+		} else {
+			err = ceph_mds_check_access(mdsc, path, MAY_WRITE);
+		}
+		ceph_mdsc_free_path(path, pathlen);
+		dput(dn);
+
+		/* For none EACCES cases will let the MDS do the mds auth check */
+		if (err == -EACCES) {
+			return err;
+		} else if (err < 0) {
+			try_async = false;
+			err = 0;
+		}
+	}
+
 retry:
 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 	if (IS_ERR(req)) {
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 16873d0769..4b8d59ebda 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -366,6 +366,12 @@ int ceph_open(struct inode *inode, struct file *file)
 	struct ceph_file_info *fi = file->private_data;
 	int err;
 	int flags, fmode, wanted;
+	struct dentry *dentry;
+	char *path;
+	int pathlen;
+	u64 pathbase;
+	bool do_sync = false;
+	int mask = MAY_READ;
 
 	if (fi) {
 		doutc(cl, "file %p is already opened\n", file);
@@ -387,6 +393,31 @@ int ceph_open(struct inode *inode, struct file *file)
 	fmode = ceph_flags_to_mode(flags);
 	wanted = ceph_caps_for_mode(fmode);
 
+	if (fmode & CEPH_FILE_MODE_WR)
+		mask |= MAY_WRITE;
+	dentry = d_find_alias(inode);
+	if (!dentry) {
+		do_sync = true;
+	} else {
+		path = ceph_mdsc_build_path(mdsc, dentry, &pathlen, &pathbase, 0);
+		if (IS_ERR(path)) {
+			do_sync = true;
+			err = 0;
+		} else {
+			err = ceph_mds_check_access(mdsc, path, mask);
+		}
+		ceph_mdsc_free_path(path, pathlen);
+		dput(dentry);
+
+		/* For none EACCES cases will let the MDS do the mds auth check */
+		if (err == -EACCES) {
+			return err;
+		} else if (err < 0) {
+			do_sync = true;
+			err = 0;
+		}
+	}
+
 	/* snapped files are read-only */
 	if (ceph_snap(inode) != CEPH_NOSNAP && (file->f_mode & FMODE_WRITE))
 		return -EROFS;
@@ -402,7 +433,7 @@ int ceph_open(struct inode *inode, struct file *file)
 	 * asynchronously.
 	 */
 	spin_lock(&ci->i_ceph_lock);
-	if (__ceph_is_any_real_caps(ci) &&
+	if (!do_sync && __ceph_is_any_real_caps(ci) &&
 	    (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
 		int mds_wanted = __ceph_caps_mds_wanted(ci, true);
 		int issued = __ceph_caps_issued(ci, NULL);
@@ -420,7 +451,7 @@ int ceph_open(struct inode *inode, struct file *file)
 			ceph_check_caps(ci, 0);
 
 		return ceph_init_file(inode, file, fmode);
-	} else if (ceph_snap(inode) != CEPH_NOSNAP &&
+	} else if (!do_sync && ceph_snap(inode) != CEPH_NOSNAP &&
 		   (ci->i_snap_caps & wanted) == wanted) {
 		__ceph_touch_fmode(ci, mdsc, fmode);
 		spin_unlock(&ci->i_ceph_lock);
@@ -759,6 +790,9 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
 	int mask;
 	int err;
+	char *path;
+	int pathlen;
+	u64 pathbase;
 
 	doutc(cl, "%p %llx.%llx dentry %p '%pd' %s flags %d mode 0%o\n",
 	      dir, ceph_vinop(dir), dentry, dentry,
@@ -776,6 +810,34 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 	 */
 	flags &= ~O_TRUNC;
 
+	dn = d_find_alias(dir);
+	if (!dn) {
+		try_async = false;
+	} else {
+		path = ceph_mdsc_build_path(mdsc, dn, &pathlen, &pathbase, 0);
+		if (IS_ERR(path)) {
+			try_async = false;
+			err = 0;
+		} else {
+			int fmode = ceph_flags_to_mode(flags);
+
+			mask = MAY_READ;
+			if (fmode & CEPH_FILE_MODE_WR)
+				mask |= MAY_WRITE;
+			err = ceph_mds_check_access(mdsc, path, mask);
+		}
+		ceph_mdsc_free_path(path, pathlen);
+		dput(dn);
+
+		/* For none EACCES cases will let the MDS do the mds auth check */
+		if (err == -EACCES) {
+			return err;
+		} else if (err < 0) {
+			try_async = false;
+			err = 0;
+		}
+	}
+
 retry:
 	if (flags & O_CREAT) {
 		if (ceph_quota_is_max_files_exceeded(dir))
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 7b2e77517f..249ddfbb1b 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -577,6 +577,8 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 
 	/* Set parameters for the netfs library */
 	netfs_inode_init(&ci->netfs, &ceph_netfs_ops, false);
+	/* [DEPRECATED] Use PG_private_2 to mark folio being written to the cache. */
+	__set_bit(NETFS_ICTX_USE_PGPRIV2, &ci->netfs.flags);
 
 	spin_lock_init(&ci->i_ceph_lock);
 
@@ -2480,6 +2482,34 @@ int __ceph_setattr(struct mnt_idmap *idmap, struct inode *inode,
 	bool lock_snap_rwsem = false;
 	bool fill_fscrypt;
 	int truncate_retry = 20; /* The RMW will take around 50ms */
+	struct dentry *dentry;
+	char *path;
+	int pathlen;
+	u64 pathbase;
+	bool do_sync = false;
+
+	dentry = d_find_alias(inode);
+	if (!dentry) {
+		do_sync = true;
+	} else {
+		path = ceph_mdsc_build_path(mdsc, dentry, &pathlen, &pathbase, 0);
+		if (IS_ERR(path)) {
+			do_sync = true;
+			err = 0;
+		} else {
+			err = ceph_mds_check_access(mdsc, path, MAY_WRITE);
+		}
+		ceph_mdsc_free_path(path, pathlen);
+		dput(dentry);
+
+		/* For none EACCES cases will let the MDS do the mds auth check */
+		if (err == -EACCES) {
+			return err;
+		} else if (err < 0) {
+			do_sync = true;
+			err = 0;
+		}
+	}
 
 retry:
 	prealloc_cf = ceph_alloc_cap_flush();
@@ -2526,7 +2556,7 @@ retry:
 		/* It should never be re-set once set */
 		WARN_ON_ONCE(ci->fscrypt_auth);
 
-		if (issued & CEPH_CAP_AUTH_EXCL) {
+		if (!do_sync && (issued & CEPH_CAP_AUTH_EXCL)) {
 			dirtied |= CEPH_CAP_AUTH_EXCL;
 			kfree(ci->fscrypt_auth);
 			ci->fscrypt_auth = (u8 *)cia->fscrypt_auth;
@@ -2555,7 +2585,7 @@ retry:
 		      ceph_vinop(inode),
 		      from_kuid(&init_user_ns, inode->i_uid),
 		      from_kuid(&init_user_ns, attr->ia_uid));
-		if (issued & CEPH_CAP_AUTH_EXCL) {
+		if (!do_sync && (issued & CEPH_CAP_AUTH_EXCL)) {
 			inode->i_uid = fsuid;
 			dirtied |= CEPH_CAP_AUTH_EXCL;
 		} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
@@ -2573,7 +2603,7 @@ retry:
 		      ceph_vinop(inode),
 		      from_kgid(&init_user_ns, inode->i_gid),
 		      from_kgid(&init_user_ns, attr->ia_gid));
-		if (issued & CEPH_CAP_AUTH_EXCL) {
+		if (!do_sync && (issued & CEPH_CAP_AUTH_EXCL)) {
 			inode->i_gid = fsgid;
 			dirtied |= CEPH_CAP_AUTH_EXCL;
 		} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
@@ -2587,7 +2617,7 @@ retry:
 	if (ia_valid & ATTR_MODE) {
 		doutc(cl, "%p %llx.%llx mode 0%o -> 0%o\n", inode,
 		      ceph_vinop(inode), inode->i_mode, attr->ia_mode);
-		if (issued & CEPH_CAP_AUTH_EXCL) {
+		if (!do_sync && (issued & CEPH_CAP_AUTH_EXCL)) {
 			inode->i_mode = attr->ia_mode;
 			dirtied |= CEPH_CAP_AUTH_EXCL;
 		} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
@@ -2606,11 +2636,11 @@ retry:
 		      inode, ceph_vinop(inode),
 		      atime.tv_sec, atime.tv_nsec,
 		      attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec);
-		if (issued & CEPH_CAP_FILE_EXCL) {
+		if (!do_sync && (issued & CEPH_CAP_FILE_EXCL)) {
 			ci->i_time_warp_seq++;
 			inode_set_atime_to_ts(inode, attr->ia_atime);
 			dirtied |= CEPH_CAP_FILE_EXCL;
-		} else if ((issued & CEPH_CAP_FILE_WR) &&
+		} else if (!do_sync && (issued & CEPH_CAP_FILE_WR) &&
 			   timespec64_compare(&atime,
 					      &attr->ia_atime) < 0) {
 			inode_set_atime_to_ts(inode, attr->ia_atime);
@@ -2646,7 +2676,7 @@ retry:
 						     CEPH_FSCRYPT_BLOCK_SIZE));
 			req->r_fscrypt_file = attr->ia_size;
 			fill_fscrypt = true;
-		} else if ((issued & CEPH_CAP_FILE_EXCL) && attr->ia_size >= isize) {
+		} else if (!do_sync && (issued & CEPH_CAP_FILE_EXCL) && attr->ia_size >= isize) {
 			if (attr->ia_size > isize) {
 				i_size_write(inode, attr->ia_size);
 				inode->i_blocks = calc_inode_blocks(attr->ia_size);
@@ -2683,11 +2713,11 @@ retry:
 		      inode, ceph_vinop(inode),
 		      mtime.tv_sec, mtime.tv_nsec,
 		      attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec);
-		if (issued & CEPH_CAP_FILE_EXCL) {
+		if (!do_sync && (issued & CEPH_CAP_FILE_EXCL)) {
 			ci->i_time_warp_seq++;
 			inode_set_mtime_to_ts(inode, attr->ia_mtime);
 			dirtied |= CEPH_CAP_FILE_EXCL;
-		} else if ((issued & CEPH_CAP_FILE_WR) &&
+		} else if (!do_sync && (issued & CEPH_CAP_FILE_WR) &&
 			   timespec64_compare(&mtime, &attr->ia_mtime) < 0) {
 			inode_set_mtime_to_ts(inode, attr->ia_mtime);
 			dirtied |= CEPH_CAP_FILE_WR;
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 360b686c3c..c2157f6e0c 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -4112,10 +4112,13 @@ static void handle_session(struct ceph_mds_session *session,
 	void *p = msg->front.iov_base;
 	void *end = p + msg->front.iov_len;
 	struct ceph_mds_session_head *h;
-	u32 op;
+	struct ceph_mds_cap_auth *cap_auths = NULL;
+	u32 op, cap_auths_num = 0;
 	u64 seq, features = 0;
 	int wake = 0;
 	bool blocklisted = false;
+	u32 i;
+
 
 	/* decode */
 	ceph_decode_need(&p, end, sizeof(*h), bad);
@@ -4160,7 +4163,101 @@ static void handle_session(struct ceph_mds_session *session,
 		}
 	}
 
+	if (msg_version >= 6) {
+		ceph_decode_32_safe(&p, end, cap_auths_num, bad);
+		doutc(cl, "cap_auths_num %d\n", cap_auths_num);
+
+		if (cap_auths_num && op != CEPH_SESSION_OPEN) {
+			WARN_ON_ONCE(op != CEPH_SESSION_OPEN);
+			goto skip_cap_auths;
+		}
+
+		cap_auths = kcalloc(cap_auths_num,
+				    sizeof(struct ceph_mds_cap_auth),
+				    GFP_KERNEL);
+		if (!cap_auths) {
+			pr_err_client(cl, "No memory for cap_auths\n");
+			return;
+		}
+
+		for (i = 0; i < cap_auths_num; i++) {
+			u32 _len, j;
+
+			/* struct_v, struct_compat, and struct_len in MDSCapAuth */
+			ceph_decode_skip_n(&p, end, 2 + sizeof(u32), bad);
+
+			/* struct_v, struct_compat, and struct_len in MDSCapMatch */
+			ceph_decode_skip_n(&p, end, 2 + sizeof(u32), bad);
+			ceph_decode_64_safe(&p, end, cap_auths[i].match.uid, bad);
+			ceph_decode_32_safe(&p, end, _len, bad);
+			if (_len) {
+				cap_auths[i].match.gids = kcalloc(_len, sizeof(u32),
+								  GFP_KERNEL);
+				if (!cap_auths[i].match.gids) {
+					pr_err_client(cl, "No memory for gids\n");
+					goto fail;
+				}
+
+				cap_auths[i].match.num_gids = _len;
+				for (j = 0; j < _len; j++)
+					ceph_decode_32_safe(&p, end,
+							    cap_auths[i].match.gids[j],
+							    bad);
+			}
+
+			ceph_decode_32_safe(&p, end, _len, bad);
+			if (_len) {
+				cap_auths[i].match.path = kcalloc(_len + 1, sizeof(char),
+								  GFP_KERNEL);
+				if (!cap_auths[i].match.path) {
+					pr_err_client(cl, "No memory for path\n");
+					goto fail;
+				}
+				ceph_decode_copy(&p, cap_auths[i].match.path, _len);
+
+				/* Remove the tailing '/' */
+				while (_len && cap_auths[i].match.path[_len - 1] == '/') {
+					cap_auths[i].match.path[_len - 1] = '\0';
+					_len -= 1;
+				}
+			}
+
+			ceph_decode_32_safe(&p, end, _len, bad);
+			if (_len) {
+				cap_auths[i].match.fs_name = kcalloc(_len + 1, sizeof(char),
+								     GFP_KERNEL);
+				if (!cap_auths[i].match.fs_name) {
+					pr_err_client(cl, "No memory for fs_name\n");
+					goto fail;
+				}
+				ceph_decode_copy(&p, cap_auths[i].match.fs_name, _len);
+			}
+
+			ceph_decode_8_safe(&p, end, cap_auths[i].match.root_squash, bad);
+			ceph_decode_8_safe(&p, end, cap_auths[i].readable, bad);
+			ceph_decode_8_safe(&p, end, cap_auths[i].writeable, bad);
+			doutc(cl, "uid %lld, num_gids %u, path %s, fs_name %s, root_squash %d, readable %d, writeable %d\n",
+			      cap_auths[i].match.uid, cap_auths[i].match.num_gids,
+			      cap_auths[i].match.path, cap_auths[i].match.fs_name,
+			      cap_auths[i].match.root_squash,
+			      cap_auths[i].readable, cap_auths[i].writeable);
+		}
+	}
+
+skip_cap_auths:
 	mutex_lock(&mdsc->mutex);
+	if (op == CEPH_SESSION_OPEN) {
+		if (mdsc->s_cap_auths) {
+			for (i = 0; i < mdsc->s_cap_auths_num; i++) {
+				kfree(mdsc->s_cap_auths[i].match.gids);
+				kfree(mdsc->s_cap_auths[i].match.path);
+				kfree(mdsc->s_cap_auths[i].match.fs_name);
+			}
+			kfree(mdsc->s_cap_auths);
+		}
+		mdsc->s_cap_auths_num = cap_auths_num;
+		mdsc->s_cap_auths = cap_auths;
+	}
 	if (op == CEPH_SESSION_CLOSE) {
 		ceph_get_mds_session(session);
 		__unregister_session(mdsc, session);
@@ -4290,6 +4387,13 @@ bad:
 	pr_err_client(cl, "corrupt message mds%d len %d\n", mds,
 		      (int)msg->front.iov_len);
 	ceph_msg_dump(msg);
+fail:
+	for (i = 0; i < cap_auths_num; i++) {
+		kfree(cap_auths[i].match.gids);
+		kfree(cap_auths[i].match.path);
+		kfree(cap_auths[i].match.fs_name);
+	}
+	kfree(cap_auths);
 	return;
 }
 
@@ -5499,6 +5603,170 @@ void send_flush_mdlog(struct ceph_mds_session *s)
 	mutex_unlock(&s->s_mutex);
 }
 
+static int ceph_mds_auth_match(struct ceph_mds_client *mdsc,
+			       struct ceph_mds_cap_auth *auth,
+			       char *tpath)
+{
+	const struct cred *cred = get_current_cred();
+	u32 caller_uid = from_kuid(&init_user_ns, cred->fsuid);
+	u32 caller_gid = from_kgid(&init_user_ns, cred->fsgid);
+	struct ceph_client *cl = mdsc->fsc->client;
+	const char *spath = mdsc->fsc->mount_options->server_path;
+	bool gid_matched = false;
+	u32 gid, tlen, len;
+	int i, j;
+
+	doutc(cl, "match.uid %lld\n", auth->match.uid);
+	if (auth->match.uid != MDS_AUTH_UID_ANY) {
+		if (auth->match.uid != caller_uid)
+			return 0;
+		if (auth->match.num_gids) {
+			for (i = 0; i < auth->match.num_gids; i++) {
+				if (caller_gid == auth->match.gids[i])
+					gid_matched = true;
+			}
+			if (!gid_matched && cred->group_info->ngroups) {
+				for (i = 0; i < cred->group_info->ngroups; i++) {
+					gid = from_kgid(&init_user_ns,
+							cred->group_info->gid[i]);
+					for (j = 0; j < auth->match.num_gids; j++) {
+						if (gid == auth->match.gids[j]) {
+							gid_matched = true;
+							break;
+						}
+					}
+					if (gid_matched)
+						break;
+				}
+			}
+			if (!gid_matched)
+				return 0;
+		}
+	}
+
+	/* path match */
+	if (auth->match.path) {
+		if (!tpath)
+			return 0;
+
+		tlen = strlen(tpath);
+		len = strlen(auth->match.path);
+		if (len) {
+			char *_tpath = tpath;
+			bool free_tpath = false;
+			int m, n;
+
+			doutc(cl, "server path %s, tpath %s, match.path %s\n",
+			      spath, tpath, auth->match.path);
+			if (spath && (m = strlen(spath)) != 1) {
+				/* mount path + '/' + tpath + an extra space */
+				n = m + 1 + tlen + 1;
+				_tpath = kmalloc(n, GFP_NOFS);
+				if (!_tpath)
+					return -ENOMEM;
+				/* remove the leading '/' */
+				snprintf(_tpath, n, "%s/%s", spath + 1, tpath);
+				free_tpath = true;
+				tlen = strlen(_tpath);
+			}
+
+			/*
+			 * Please note the tailing '/' for match.path has already
+			 * been removed when parsing.
+			 *
+			 * Remove the tailing '/' for the target path.
+			 */
+			while (tlen && _tpath[tlen - 1] == '/') {
+				_tpath[tlen - 1] = '\0';
+				tlen -= 1;
+			}
+			doutc(cl, "_tpath %s\n", _tpath);
+
+			/*
+			 * In case first == _tpath && tlen == len:
+			 *  match.path=/foo  --> /foo _path=/foo     --> match
+			 *  match.path=/foo/ --> /foo _path=/foo     --> match
+			 *
+			 * In case first == _tmatch.path && tlen > len:
+			 *  match.path=/foo/ --> /foo _path=/foo/    --> match
+			 *  match.path=/foo  --> /foo _path=/foo/    --> match
+			 *  match.path=/foo/ --> /foo _path=/foo/d   --> match
+			 *  match.path=/foo  --> /foo _path=/food    --> mismatch
+			 *
+			 * All the other cases                       --> mismatch
+			 */
+			char *first = strstr(_tpath, auth->match.path);
+			if (first != _tpath) {
+				if (free_tpath)
+					kfree(_tpath);
+				return 0;
+			}
+
+			if (tlen > len && _tpath[len] != '/') {
+				if (free_tpath)
+					kfree(_tpath);
+				return 0;
+			}
+		}
+	}
+
+	doutc(cl, "matched\n");
+	return 1;
+}
+
+int ceph_mds_check_access(struct ceph_mds_client *mdsc, char *tpath, int mask)
+{
+	const struct cred *cred = get_current_cred();
+	u32 caller_uid = from_kuid(&init_user_ns, cred->fsuid);
+	u32 caller_gid = from_kgid(&init_user_ns, cred->fsgid);
+	struct ceph_mds_cap_auth *rw_perms_s = NULL;
+	struct ceph_client *cl = mdsc->fsc->client;
+	bool root_squash_perms = true;
+	int i, err;
+
+	doutc(cl, "tpath '%s', mask %d, caller_uid %d, caller_gid %d\n",
+	      tpath, mask, caller_uid, caller_gid);
+
+	for (i = 0; i < mdsc->s_cap_auths_num; i++) {
+		struct ceph_mds_cap_auth *s = &mdsc->s_cap_auths[i];
+
+		err = ceph_mds_auth_match(mdsc, s, tpath);
+		if (err < 0) {
+			return err;
+		} else if (err > 0) {
+			/* always follow the last auth caps' permision */
+			root_squash_perms = true;
+			rw_perms_s = NULL;
+			if ((mask & MAY_WRITE) && s->writeable &&
+			    s->match.root_squash && (!caller_uid || !caller_gid))
+				root_squash_perms = false;
+
+			if (((mask & MAY_WRITE) && !s->writeable) ||
+			    ((mask & MAY_READ) && !s->readable))
+				rw_perms_s = s;
+		}
+	}
+
+	doutc(cl, "root_squash_perms %d, rw_perms_s %p\n", root_squash_perms,
+	      rw_perms_s);
+	if (root_squash_perms && rw_perms_s == NULL) {
+		doutc(cl, "access allowed\n");
+		return 0;
+	}
+
+	if (!root_squash_perms) {
+		doutc(cl, "root_squash is enabled and user(%d %d) isn't allowed to write",
+		      caller_uid, caller_gid);
+	}
+	if (rw_perms_s) {
+		doutc(cl, "mds auth caps readable/writeable %d/%d while request r/w %d/%d",
+		      rw_perms_s->readable, rw_perms_s->writeable,
+		      !!(mask & MAY_READ), !!(mask & MAY_WRITE));
+	}
+	doutc(cl, "access denied\n");
+	return -EACCES;
+}
+
 /*
  * called before mount is ro, and before dentries are torn down.
  * (hmm, does this still race with new lookups?)
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index b88e804152..cfa18cf915 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -35,8 +35,9 @@ enum ceph_feature_type {
 	CEPHFS_FEATURE_32BITS_RETRY_FWD,
 	CEPHFS_FEATURE_NEW_SNAPREALM_INFO,
 	CEPHFS_FEATURE_HAS_OWNER_UIDGID,
+	CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK,
 
-	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_HAS_OWNER_UIDGID,
+	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK,
 };
 
 #define CEPHFS_FEATURES_CLIENT_SUPPORTED {	\
@@ -52,6 +53,7 @@ enum ceph_feature_type {
 	CEPHFS_FEATURE_OP_GETVXATTR,		\
 	CEPHFS_FEATURE_32BITS_RETRY_FWD,	\
 	CEPHFS_FEATURE_HAS_OWNER_UIDGID,	\
+	CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK,	\
 }
 
 /*
@@ -71,6 +73,24 @@ enum ceph_feature_type {
 struct ceph_fs_client;
 struct ceph_cap;
 
+#define MDS_AUTH_UID_ANY -1
+
+struct ceph_mds_cap_match {
+	s64 uid;  /* default to MDS_AUTH_UID_ANY */
+	u32 num_gids;
+	u32 *gids;  /* use these GIDs */
+	char *path;  /* require path to be child of this
+			(may be "" or "/" for any) */
+	char *fs_name;
+	bool root_squash;  /* default to false */
+};
+
+struct ceph_mds_cap_auth {
+	struct ceph_mds_cap_match match;
+	bool readable;
+	bool writeable;
+};
+
 /*
  * parsed info about a single inode.  pointers are into the encoded
  * on-wire structures within the mds reply message payload.
@@ -513,6 +533,9 @@ struct ceph_mds_client {
 	struct rw_semaphore     pool_perm_rwsem;
 	struct rb_root		pool_perm_tree;
 
+	u32			 s_cap_auths_num;
+	struct ceph_mds_cap_auth *s_cap_auths;
+
 	char nodename[__NEW_UTS_LEN + 1];
 };
 
@@ -581,6 +604,9 @@ extern void ceph_queue_cap_unlink_work(struct ceph_mds_client *mdsc);
 extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
 				     int (*cb)(struct inode *, int mds, void *),
 				     void *arg);
+extern int ceph_mds_check_access(struct ceph_mds_client *mdsc, char *tpath,
+				 int mask);
+
 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 
 static inline void ceph_mdsc_free_path(char *path, int len)
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 885cb5d4e7..0cdf84cd17 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -961,7 +961,8 @@ static int __init init_caches(void)
 	if (!ceph_mds_request_cachep)
 		goto bad_mds_req;
 
-	ceph_wb_pagevec_pool = mempool_create_kmalloc_pool(10, CEPH_MAX_WRITE_SIZE >> PAGE_SHIFT);
+	ceph_wb_pagevec_pool = mempool_create_kmalloc_pool(10,
+	    (CEPH_MAX_WRITE_SIZE >> PAGE_SHIFT) * sizeof(struct page *));
 	if (!ceph_wb_pagevec_pool)
 		goto bad_pagevec_pool;