Merge tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs

Pull UBIFS updates from Richard Weinberger:

 - Fix for a race xattr list and modification

 - Various minor fixes (spelling, return codes, ...)

* tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubifs: Set/Clear I_LINKABLE under i_lock for whiteout inode
  ubifs: Fix spelling mistakes
  ubifs: Remove ui_mutex in ubifs_xattr_get and change_xattr
  ubifs: Fix races between xattr_{set|get} and listxattr operations
  ubifs: fix snprintf() checking
  ubifs: journal: Fix error return code in ubifs_jnl_write_inode()

9 files changed, 51 insertions, 22 deletions

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 1bbb9fe661b1..fc718f6178f2 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2824,7 +2824,7 @@ void dbg_debugfs_init_fs(struct ubifs_info *c)
 
 	n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,
 		     c->vi.ubi_num, c->vi.vol_id);
-	if (n == UBIFS_DFS_DIR_LEN) {
+	if (n > UBIFS_DFS_DIR_LEN) {
 		/* The array size is too small */
 		return;
 	}
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 5bd8482e660a..7c61d0ec0159 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1337,7 +1337,10 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
 			goto out_release;
 		}
 
+		spin_lock(&whiteout->i_lock);
 		whiteout->i_state |= I_LINKABLE;
+		spin_unlock(&whiteout->i_lock);
+
 		whiteout_ui = ubifs_inode(whiteout);
 		whiteout_ui->data = dev;
 		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
@@ -1430,7 +1433,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 		inc_nlink(whiteout);
 		mark_inode_dirty(whiteout);
+
+		spin_lock(&whiteout->i_lock);
 		whiteout->i_state &= ~I_LINKABLE;
+		spin_unlock(&whiteout->i_lock);
+
 		iput(whiteout);
 	}
 
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index 2857e64d673d..8ea680dba61e 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -882,6 +882,7 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
 		struct ubifs_dent_node *xent, *pxent = NULL;
 
 		if (ui->xattr_cnt > ubifs_xattr_max_cnt(c)) {
+			err = -EPERM;
 			ubifs_err(c, "Cannot delete inode, it has too much xattrs!");
 			goto out_release;
 		}
@@ -1431,7 +1432,7 @@ out_free:
 /**
  * truncate_data_node - re-compress/encrypt a truncated data node.
  * @c: UBIFS file-system description object
- * @inode: inode which referes to the data node
+ * @inode: inode which refers to the data node
  * @block: data block number
  * @dn: data node to re-compress
  * @new_len: new length
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index 0df9a3dd0aaa..7adc37c10b6a 100644
--- a/fs/ubifs/master.c
+++ b/fs/ubifs/master.c
@@ -37,7 +37,7 @@ int ubifs_compare_master_node(struct ubifs_info *c, void *m1, void *m2)
 		return ret;
 
 	/*
-	 * Do not compare the embedded HMAC aswell which also must be different
+	 * Do not compare the embedded HMAC as well which also must be different
 	 * due to the different common node header.
 	 */
 	behind = hmac_offs + UBIFS_MAX_HMAC_LEN;
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
index 382a54c82930..5260d3e531bb 100644
--- a/fs/ubifs/replay.c
+++ b/fs/ubifs/replay.c
@@ -296,7 +296,7 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
  * @b: second replay entry
  *
  * This is a comparios function for 'list_sort()' which compares 2 replay
- * entries @a and @b by comparing their sequence numer.  Returns %1 if @a has
+ * entries @a and @b by comparing their sequence number.  Returns %1 if @a has
  * greater sequence number and %-1 otherwise.
  */
 static int replay_entries_cmp(void *priv, const struct list_head *a,
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 7b572e1414ba..f0fb25727d96 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -275,6 +275,7 @@ static struct inode *ubifs_alloc_inode(struct super_block *sb)
 	memset((void *)ui + sizeof(struct inode), 0,
 	       sizeof(struct ubifs_inode) - sizeof(struct inode));
 	mutex_init(&ui->ui_mutex);
+	init_rwsem(&ui->xattr_sem);
 	spin_lock_init(&ui->ui_lock);
 	return &ui->vfs_inode;
 };
@@ -2060,7 +2061,7 @@ const struct super_operations ubifs_super_operations = {
  * @mode: UBI volume open mode
  *
  * The primary method of mounting UBIFS is by specifying the UBI volume
- * character device node path. However, UBIFS may also be mounted withoug any
+ * character device node path. However, UBIFS may also be mounted without any
  * character device node using one of the following methods:
  *
  * o ubiX_Y    - mount UBI device number X, volume Y;
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 234be1c4dc87..58c92c96ecef 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -930,7 +930,7 @@ static int write_index(struct ubifs_info *c)
 		 * flag cleared before %COW_ZNODE. Specifically, it matters in
 		 * the 'dirty_cow_znode()' function. This is the reason for the
 		 * first barrier. Also, we want the bit changes to be seen to
-		 * other threads ASAP, to avoid unnecesarry copying, which is
+		 * other threads ASAP, to avoid unnecessary copying, which is
 		 * the reason for the second barrier.
 		 */
 		clear_bit(DIRTY_ZNODE, &znode->flags);
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index b65c599a386a..c38066ce9ab0 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -356,6 +356,7 @@ struct ubifs_gced_idx_leb {
  * @ui_mutex: serializes inode write-back with the rest of VFS operations,
  *            serializes "clean <-> dirty" state changes, serializes bulk-read,
  *            protects @dirty, @bulk_read, @ui_size, and @xattr_size
+ * @xattr_sem: serilizes write operations (remove|set|create) on xattr
  * @ui_lock: protects @synced_i_size
  * @synced_i_size: synchronized size of inode, i.e. the value of inode size
  *                 currently stored on the flash; used only for regular file
@@ -409,6 +410,7 @@ struct ubifs_inode {
 	unsigned int bulk_read:1;
 	unsigned int compr_type:2;
 	struct mutex ui_mutex;
+	struct rw_semaphore xattr_sem;
 	spinlock_t ui_lock;
 	loff_t synced_i_size;
 	loff_t ui_size;
@@ -912,7 +914,7 @@ struct ubifs_budget_req {
  * @rb: rb-tree node of rb-tree of orphans sorted by inode number
  * @list: list head of list of orphans in order added
  * @new_list: list head of list of orphans added since the last commit
- * @child_list: list of xattr childs if this orphan hosts xattrs, list head
+ * @child_list: list of xattr children if this orphan hosts xattrs, list head
  * if this orphan is a xattr, not used otherwise.
  * @cnext: next orphan to commit
  * @dnext: next orphan to delete
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 6b1e9830b274..e4f193eae4b2 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -208,13 +208,11 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
 		err = -ENOMEM;
 		goto out_free;
 	}
-	mutex_lock(&ui->ui_mutex);
 	kfree(ui->data);
 	ui->data = buf;
 	inode->i_size = ui->ui_size = size;
 	old_size = ui->data_len;
 	ui->data_len = size;
-	mutex_unlock(&ui->ui_mutex);
 
 	mutex_lock(&host_ui->ui_mutex);
 	host->i_ctime = current_time(host);
@@ -285,6 +283,7 @@ int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
 	if (!xent)
 		return -ENOMEM;
 
+	down_write(&ubifs_inode(host)->xattr_sem);
 	/*
 	 * The extended attribute entries are stored in LNC, so multiple
 	 * look-ups do not involve reading the flash.
@@ -319,6 +318,7 @@ int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
 	iput(inode);
 
 out_free:
+	up_write(&ubifs_inode(host)->xattr_sem);
 	kfree(xent);
 	return err;
 }
@@ -341,25 +341,25 @@ ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
 	if (!xent)
 		return -ENOMEM;
 
+	down_read(&ubifs_inode(host)->xattr_sem);
 	xent_key_init(c, &key, host->i_ino, &nm);
 	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
 	if (err) {
 		if (err == -ENOENT)
 			err = -ENODATA;
-		goto out_unlock;
+		goto out_cleanup;
 	}
 
 	inode = iget_xattr(c, le64_to_cpu(xent->inum));
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
-		goto out_unlock;
+		goto out_cleanup;
 	}
 
 	ui = ubifs_inode(inode);
 	ubifs_assert(c, inode->i_size == ui->data_len);
 	ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
 
-	mutex_lock(&ui->ui_mutex);
 	if (buf) {
 		/* If @buf is %NULL we are supposed to return the length */
 		if (ui->data_len > size) {
@@ -372,9 +372,9 @@ ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
 	err = ui->data_len;
 
 out_iput:
-	mutex_unlock(&ui->ui_mutex);
 	iput(inode);
-out_unlock:
+out_cleanup:
+	up_read(&ubifs_inode(host)->xattr_sem);
 	kfree(xent);
 	return err;
 }
@@ -406,16 +406,21 @@ ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 	dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino,
 		dentry, size);
 
+	down_read(&host_ui->xattr_sem);
 	len = host_ui->xattr_names + host_ui->xattr_cnt;
-	if (!buffer)
+	if (!buffer) {
 		/*
 		 * We should return the minimum buffer size which will fit a
 		 * null-terminated list of all the extended attribute names.
 		 */
-		return len;
+		err = len;
+		goto out_err;
+	}
 
-	if (len > size)
-		return -ERANGE;
+	if (len > size) {
+		err = -ERANGE;
+		goto out_err;
+	}
 
 	lowest_xent_key(c, &key, host->i_ino);
 	while (1) {
@@ -437,8 +442,9 @@ ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 		pxent = xent;
 		key_read(c, &xent->key, &key);
 	}
-
 	kfree(pxent);
+	up_read(&host_ui->xattr_sem);
+
 	if (err != -ENOENT) {
 		ubifs_err(c, "cannot find next direntry, error %d", err);
 		return err;
@@ -446,6 +452,10 @@ ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
 	ubifs_assert(c, written <= size);
 	return written;
+
+out_err:
+	up_read(&host_ui->xattr_sem);
+	return err;
 }
 
 static int remove_xattr(struct ubifs_info *c, struct inode *host,
@@ -504,6 +514,7 @@ int ubifs_purge_xattrs(struct inode *host)
 	ubifs_warn(c, "inode %lu has too many xattrs, doing a non-atomic deletion",
 		   host->i_ino);
 
+	down_write(&ubifs_inode(host)->xattr_sem);
 	lowest_xent_key(c, &key, host->i_ino);
 	while (1) {
 		xent = ubifs_tnc_next_ent(c, &key, &nm);
@@ -523,7 +534,7 @@ int ubifs_purge_xattrs(struct inode *host)
 			ubifs_ro_mode(c, err);
 			kfree(pxent);
 			kfree(xent);
-			return err;
+			goto out_err;
 		}
 
 		ubifs_assert(c, ubifs_inode(xino)->xattr);
@@ -535,7 +546,7 @@ int ubifs_purge_xattrs(struct inode *host)
 			kfree(xent);
 			iput(xino);
 			ubifs_err(c, "cannot remove xattr, error %d", err);
-			return err;
+			goto out_err;
 		}
 
 		iput(xino);
@@ -544,14 +555,19 @@ int ubifs_purge_xattrs(struct inode *host)
 		pxent = xent;
 		key_read(c, &xent->key, &key);
 	}
-
 	kfree(pxent);
+	up_write(&ubifs_inode(host)->xattr_sem);
+
 	if (err != -ENOENT) {
 		ubifs_err(c, "cannot find next direntry, error %d", err);
 		return err;
 	}
 
 	return 0;
+
+out_err:
+	up_write(&ubifs_inode(host)->xattr_sem);
+	return err;
 }
 
 /**
@@ -594,6 +610,7 @@ static int ubifs_xattr_remove(struct inode *host, const char *name)
 	if (!xent)
 		return -ENOMEM;
 
+	down_write(&ubifs_inode(host)->xattr_sem);
 	xent_key_init(c, &key, host->i_ino, &nm);
 	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
 	if (err) {
@@ -618,6 +635,7 @@ static int ubifs_xattr_remove(struct inode *host, const char *name)
 	iput(inode);
 
 out_free:
+	up_write(&ubifs_inode(host)->xattr_sem);
 	kfree(xent);
 	return err;
 }