shithub: lwext4

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FIX: ext4_frename does not check whether the target file exist or not.

--- a/lwext4/ext4.c

+++ b/lwext4/ext4.c

@@ -180,7 +180,7 @@

 static int ext4_link(struct ext4_mountpoint *mp, struct ext4_inode_ref *parent,

 		     struct ext4_inode_ref *child, const char *name,

-		     uint32_t name_len)

+		     uint32_t name_len, bool rename)

 {

 	/* Check maximum name length */

 	if (name_len > EXT4_DIRECTORY_FILENAME_LEN)

@@ -196,7 +196,7 @@

 	 */

 	if (ext4_inode_is_type(&mp->fs.sb, child->inode,

 			       EXT4_INODE_MODE_DIRECTORY) &&

-	    ext4_inode_get_links_count(child->inode) == 0) {

+	    !rename) {

 		rc = ext4_dir_add_entry(child, ".", strlen("."), child);

 		if (rc != EOK) {

 			ext4_dir_remove_entry(parent, name, strlen(name));

@@ -231,6 +231,10 @@

 		child->dirty = true;

 		parent->dirty = true;

 	} else {

+		/*

+		 * In case we want to rename a directory,

+		 * we reset the original '..' pointer.

+		 */

 		if (ext4_inode_is_type(&mp->fs.sb, child->inode,

 					EXT4_INODE_MODE_DIRECTORY)) {

 			int has_flag_index =

@@ -263,7 +267,8 @@

 			ext4_fs_inode_links_count_inc(parent);

 			parent->dirty = true;

-		} else {

+		}

+		if (!rename) {

 			ext4_fs_inode_links_count_inc(child);

 			child->dirty = true;

 		}

@@ -632,6 +637,9 @@

 		r = ext4_dir_find_entry(&result, &ref, path, len);

 		if (r != EOK) {

+			/*Destroy last result*/

+			ext4_dir_destroy_result(&ref, &result);

+

 			if (r != ENOENT)

 				break;

@@ -647,11 +655,9 @@

 			if (r != EOK)

 				break;

-			/*Destroy last result*/

-			ext4_dir_destroy_result(&ref, &result);

 			/*Link with root dir.*/

-			r = ext4_link(mp, &ref, &child_ref, path, len);

+			r = ext4_link(mp, &ref, &child_ref, path, len, false);

 			if (r != EOK) {

 				/*Fail. Free new inode.*/

 				ext4_fs_free_inode(&child_ref);

@@ -758,7 +764,8 @@

 }

 static int __ext4_create_hardlink(const char *path,

-		struct ext4_inode_ref *child_ref)

+		struct ext4_inode_ref *child_ref,

+		bool rename)

 {

 	bool is_goal = false;

 	uint8_t inode_type = EXT4_DIRENTRY_DIR;

@@ -799,14 +806,19 @@

 		r = ext4_dir_find_entry(&result, &ref, path, len);

 		if (r != EOK) {

+			/*Destroy last result*/

+			ext4_dir_destroy_result(&ref, &result);

+

 			if (r != ENOENT || !is_goal)

 				break;

+			/*Link with root dir.*/

+			r = ext4_link(mp, &ref, child_ref, path, len, rename);

+			break;

+		} else if (r == EOK && is_goal) {

 			/*Destroy last result*/

 			ext4_dir_destroy_result(&ref, &result);

-

-			/*Link with root dir.*/

-			r = ext4_link(mp, &ref, child_ref, path, len);

+			r = EEXIST;

 			break;

 		}

@@ -850,10 +862,10 @@

 	return r;

 }

-static int __ext4_remove_hardlink(const char *path,

-				  uint32_t name_off,

-				  struct ext4_inode_ref *parent_ref,

-				  struct ext4_inode_ref *child_ref)

+static int ext4_remove_orig_reference(const char *path,

+				      uint32_t name_off,

+				      struct ext4_inode_ref *parent_ref,

+				      struct ext4_inode_ref *child_ref)

 {

 	bool is_goal;

 	int r;

@@ -868,11 +880,16 @@

 	len = ext4_path_check(path, &is_goal);

-	/*Unlink from parent*/

-	r = ext4_unlink(mp, parent_ref, child_ref, path, len);

+	/* Remove entry from parent directory */

+	r = ext4_dir_remove_entry(parent_ref, path, len);

 	if (r != EOK)

 		goto Finish;

+	if (ext4_inode_is_type(&mp->fs.sb, child_ref->inode,

+			       EXT4_INODE_MODE_DIRECTORY)) {

+		ext4_fs_inode_links_count_dec(parent_ref);

+		parent_ref->dirty = true;

+	}

 Finish:

 	return r;

 }

@@ -913,8 +930,15 @@

 	child_loaded = true;

-	r = __ext4_create_hardlink(hardlink_path, &child_ref);

+	/* Creating hardlink for directory is not allowed. */

+	if (ext4_inode_is_type(&mp->fs.sb, child_ref.inode,

+			       EXT4_INODE_MODE_DIRECTORY)) {

+		r = EINVAL;

+		goto Finish;

+	}

+	r = __ext4_create_hardlink(hardlink_path, &child_ref, false);

+

 Finish:

 	if (child_loaded)

 		ext4_fs_put_inode_ref(&child_ref);

@@ -962,11 +986,12 @@

 	child_loaded = true;

-	r = __ext4_create_hardlink(new_path, &child_ref);

+	r = __ext4_create_hardlink(new_path, &child_ref, true);

 	if (r != EOK)

 		goto Finish;

-	r = __ext4_remove_hardlink(path, name_off, &parent_ref, &child_ref);

+	r = ext4_remove_orig_reference(path, name_off,

+				       &parent_ref, &child_ref);

 	if (r != EOK)

 		goto Finish;