[readdir] convert ext4

and trim the living hell out bogosities in inline dir case
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ext4/ext4.h

@@ -2515,7 +2515,7 @@ extern int ext4_try_create_inline_dir(handle_t *handle,
 				      struct inode *parent,
 				      struct inode *inode);
 extern int ext4_read_inline_dir(struct file *filp,
-				void *dirent, filldir_t filldir,
+				struct dir_context *ctx,
 				int *has_inline_data);
 extern int htree_inlinedir_to_tree(struct file *dir_file,
 				   struct inode *dir, ext4_lblk_t block,

fs/ext4/inline.c

@@ -1404,16 +1404,15 @@ int htree_inlinedir_to_tree(struct file *dir_file,
  * offset as if '.' and '..' really take place.
  *
  */
-int ext4_read_inline_dir(struct file *filp,
-			 void *dirent, filldir_t filldir,
+int ext4_read_inline_dir(struct file *file,
+			 struct dir_context *ctx,
 			 int *has_inline_data)
 {
-	int error = 0;
 	unsigned int offset, parent_ino;
-	int i, stored;
+	int i;
 	struct ext4_dir_entry_2 *de;
 	struct super_block *sb;
-	struct inode *inode = file_inode(filp);
+	struct inode *inode = file_inode(file);
 	int ret, inline_size = 0;
 	struct ext4_iloc iloc;
 	void *dir_buf = NULL;
@@ -1444,9 +1443,8 @@ int ext4_read_inline_dir(struct file *filp,
 		goto out;
 
 	sb = inode->i_sb;
-	stored = 0;
 	parent_ino = le32_to_cpu(((struct ext4_dir_entry_2 *)dir_buf)->inode);
-	offset = filp->f_pos;
+	offset = ctx->pos;
 
 	/*
 	 * dotdot_offset and dotdot_size is the real offset and
@@ -1460,104 +1458,74 @@ int ext4_read_inline_dir(struct file *filp,
 	extra_offset = dotdot_size - EXT4_INLINE_DOTDOT_SIZE;
 	extra_size = extra_offset + inline_size;
 
-	while (!error && !stored && filp->f_pos < extra_size) {
-revalidate:
-		/*
-		 * If the version has changed since the last call to
-		 * readdir(2), then we might be pointing to an invalid
-		 * dirent right now.  Scan from the start of the inline
-		 * dir to make sure.
-		 */
-		if (filp->f_version != inode->i_version) {
-			for (i = 0; i < extra_size && i < offset;) {
-				/*
-				 * "." is with offset 0 and
-				 * ".." is dotdot_offset.
-				 */
-				if (!i) {
-					i = dotdot_offset;
-					continue;
-				} else if (i == dotdot_offset) {
-					i = dotdot_size;
-					continue;
-				}
-				/* for other entry, the real offset in
-				 * the buf has to be tuned accordingly.
-				 */
-				de = (struct ext4_dir_entry_2 *)
-					(dir_buf + i - extra_offset);
-				/* It's too expensive to do a full
-				 * dirent test each time round this
-				 * loop, but we do have to test at
-				 * least that it is non-zero.  A
-				 * failure will be detected in the
-				 * dirent test below. */
-				if (ext4_rec_len_from_disk(de->rec_len,
-					extra_size) < EXT4_DIR_REC_LEN(1))
-					break;
-				i += ext4_rec_len_from_disk(de->rec_len,
-							    extra_size);
-			}
-			offset = i;
-			filp->f_pos = offset;
-			filp->f_version = inode->i_version;
-		}
-
-		while (!error && filp->f_pos < extra_size) {
-			if (filp->f_pos == 0) {
-				error = filldir(dirent, ".", 1, 0, inode->i_ino,
-						DT_DIR);
-				if (error)
-					break;
-				stored++;
-				filp->f_pos = dotdot_offset;
+	/*
+	 * If the version has changed since the last call to
+	 * readdir(2), then we might be pointing to an invalid
+	 * dirent right now.  Scan from the start of the inline
+	 * dir to make sure.
+	 */
+	if (file->f_version != inode->i_version) {
+		for (i = 0; i < extra_size && i < offset;) {
+			/*
+			 * "." is with offset 0 and
+			 * ".." is dotdot_offset.
+			 */
+			if (!i) {
+				i = dotdot_offset;
+				continue;
+			} else if (i == dotdot_offset) {
+				i = dotdot_size;
 				continue;
 			}
+			/* for other entry, the real offset in
+			 * the buf has to be tuned accordingly.
+			 */
+			de = (struct ext4_dir_entry_2 *)
+				(dir_buf + i - extra_offset);
+			/* It's too expensive to do a full
+			 * dirent test each time round this
+			 * loop, but we do have to test at
+			 * least that it is non-zero.  A
+			 * failure will be detected in the
+			 * dirent test below. */
+			if (ext4_rec_len_from_disk(de->rec_len, extra_size)
+				< EXT4_DIR_REC_LEN(1))
+				break;
+			i += ext4_rec_len_from_disk(de->rec_len,
+						    extra_size);
+		}
+		offset = i;
+		ctx->pos = offset;
+		file->f_version = inode->i_version;
+	}
 
-			if (filp->f_pos == dotdot_offset) {
-				error = filldir(dirent, "..", 2,
-						dotdot_offset,
-						parent_ino, DT_DIR);
-				if (error)
-					break;
-				stored++;
+	while (ctx->pos < extra_size) {
+		if (ctx->pos == 0) {
+			if (!dir_emit(ctx, ".", 1, inode->i_ino, DT_DIR))
+				goto out;
+			ctx->pos = dotdot_offset;
+			continue;
+		}
 
-				filp->f_pos = dotdot_size;
-				continue;
-			}
+		if (ctx->pos == dotdot_offset) {
+			if (!dir_emit(ctx, "..", 2, parent_ino, DT_DIR))
+				goto out;
+			ctx->pos = dotdot_size;
+			continue;
+		}
 
-			de = (struct ext4_dir_entry_2 *)
-				(dir_buf + filp->f_pos - extra_offset);
-			if (ext4_check_dir_entry(inode, filp, de,
-						 iloc.bh, dir_buf,
-						 extra_size, filp->f_pos)) {
-				ret = stored;
+		de = (struct ext4_dir_entry_2 *)
+			(dir_buf + ctx->pos - extra_offset);
+		if (ext4_check_dir_entry(inode, file, de, iloc.bh, dir_buf,
+					 extra_size, ctx->pos))
+			goto out;
+		if (le32_to_cpu(de->inode)) {
+			if (!dir_emit(ctx, de->name, de->name_len,
+				      le32_to_cpu(de->inode),
+				      get_dtype(sb, de->file_type)))
 				goto out;
-			}
-			if (le32_to_cpu(de->inode)) {
-				/* We might block in the next section
-				 * if the data destination is
-				 * currently swapped out.  So, use a
-				 * version stamp to detect whether or
-				 * not the directory has been modified
-				 * during the copy operation.
-				 */
-				u64 version = filp->f_version;
-
-				error = filldir(dirent, de->name,
-						de->name_len,
-						filp->f_pos,
-						le32_to_cpu(de->inode),
-						get_dtype(sb, de->file_type));
-				if (error)
-					break;
-				if (version != filp->f_version)
-					goto revalidate;
-				stored++;
-			}
-			filp->f_pos += ext4_rec_len_from_disk(de->rec_len,
-							      extra_size);
 		}
+		ctx->pos += ext4_rec_len_from_disk(de->rec_len, extra_size);
 	}
 out:
 	kfree(dir_buf);