1 files changed, 34 insertions, 35 deletions

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index de08c92f2e23..6b4947f75af7 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -346,38 +346,46 @@ static unsigned int vfs_dent_type(uint8_t type)
  * This means that UBIFS cannot support NFS which requires full
  * 'seekdir()'/'telldir()' support.
  */
-static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
+static int ubifs_readdir(struct file *file, struct dir_context *ctx)
 {
-	int err, over = 0;
+	int err;
 	struct qstr nm;
 	union ubifs_key key;
 	struct ubifs_dent_node *dent;
 	struct inode *dir = file_inode(file);
 	struct ubifs_info *c = dir->i_sb->s_fs_info;
 
-	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
+	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
 
-	if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
+	if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
 		/*
 		 * The directory was seek'ed to a senseless position or there
 		 * are no more entries.
 		 */
 		return 0;
 
-	/* File positions 0 and 1 correspond to "." and ".." */
-	if (file->f_pos == 0) {
-		ubifs_assert(!file->private_data);
-		over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
-		if (over)
-			return 0;
-		file->f_pos = 1;
+	if (file->f_version == 0) {
+		/*
+		 * The file was seek'ed, which means that @file->private_data
+		 * is now invalid. This may also be just the first
+		 * 'ubifs_readdir()' invocation, in which case
+		 * @file->private_data is NULL, and the below code is
+		 * basically a no-op.
+		 */
+		kfree(file->private_data);
+		file->private_data = NULL;
 	}
 
-	if (file->f_pos == 1) {
+	/*
+	 * 'generic_file_llseek()' unconditionally sets @file->f_version to
+	 * zero, and we use this for detecting whether the file was seek'ed.
+	 */
+	file->f_version = 1;
+
+	/* File positions 0 and 1 correspond to "." and ".." */
+	if (ctx->pos < 2) {
 		ubifs_assert(!file->private_data);
-		over = filldir(dirent, "..", 2, 1,
-			       parent_ino(file->f_path.dentry), DT_DIR);
-		if (over)
+		if (!dir_emit_dots(file, ctx))
 			return 0;
 
 		/* Find the first entry in TNC and save it */
@@ -389,7 +397,7 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
 			goto out;
 		}
 
-		file->f_pos = key_hash_flash(c, &dent->key);
+		ctx->pos = key_hash_flash(c, &dent->key);
 		file->private_data = dent;
 	}
 
@@ -397,17 +405,16 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
 	if (!dent) {
 		/*
 		 * The directory was seek'ed to and is now readdir'ed.
-		 * Find the entry corresponding to @file->f_pos or the
-		 * closest one.
+		 * Find the entry corresponding to @ctx->pos or the closest one.
 		 */
-		dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
+		dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
 		nm.name = NULL;
 		dent = ubifs_tnc_next_ent(c, &key, &nm);
 		if (IS_ERR(dent)) {
 			err = PTR_ERR(dent);
 			goto out;
 		}
-		file->f_pos = key_hash_flash(c, &dent->key);
+		ctx->pos = key_hash_flash(c, &dent->key);
 		file->private_data = dent;
 	}
 
@@ -419,10 +426,9 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
 			     ubifs_inode(dir)->creat_sqnum);
 
 		nm.len = le16_to_cpu(dent->nlen);
-		over = filldir(dirent, dent->name, nm.len, file->f_pos,
+		if (!dir_emit(ctx, dent->name, nm.len,
 			       le64_to_cpu(dent->inum),
-			       vfs_dent_type(dent->type));
-		if (over)
+			       vfs_dent_type(dent->type)))
 			return 0;
 
 		/* Switch to the next entry */
@@ -435,7 +441,7 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
 		}
 
 		kfree(file->private_data);
-		file->f_pos = key_hash_flash(c, &dent->key);
+		ctx->pos = key_hash_flash(c, &dent->key);
 		file->private_data = dent;
 		cond_resched();
 	}
@@ -448,18 +454,11 @@ out:
 
 	kfree(file->private_data);
 	file->private_data = NULL;
-	file->f_pos = 2;
+	/* 2 is a special value indicating that there are no more direntries */
+	ctx->pos = 2;
 	return 0;
 }
 
-/* If a directory is seeked, we have to free saved readdir() state */
-static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int whence)
-{
-	kfree(file->private_data);
-	file->private_data = NULL;
-	return generic_file_llseek(file, offset, whence);
-}
-
 /* Free saved readdir() state when the directory is closed */
 static int ubifs_dir_release(struct inode *dir, struct file *file)
 {
@@ -1177,10 +1176,10 @@ const struct inode_operations ubifs_dir_inode_operations = {
 };
 
 const struct file_operations ubifs_dir_operations = {
-	.llseek         = ubifs_dir_llseek,
+	.llseek         = generic_file_llseek,
 	.release        = ubifs_dir_release,
 	.read           = generic_read_dir,
-	.readdir        = ubifs_readdir,
+	.iterate        = ubifs_readdir,
 	.fsync          = ubifs_fsync,
 	.unlocked_ioctl = ubifs_ioctl,
 #ifdef CONFIG_COMPAT