ext2: ext2_find_entry() return -ENOENT if no entry found

Almost all callers of ext2_find_entry() transform NULL return value to
-ENOENT, so just let ext2_find_entry() retuen -ENOENT instead of NULL
if no valid entry found, and also switch to check the return value of
ext2_inode_by_name() in ext2_lookup() and ext2_get_parent().

Link: https://lore.kernel.org/r/20200608034043.10451-2-yi.zhang@huawei.com
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 95e4f0bd55a3ea93d5a198b8463e27b2726a95bb..70355ab6740ee94e752fd2b034f32a236444369a 100644 (file)
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -393,7 +393,7 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
                }
        } while (n != start);
 out:
-       return NULL;
+       return ERR_PTR(-ENOENT);
 
 found:
        *res_page = page;
@@ -419,7 +419,7 @@ int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino)
        struct page *page;
        
        de = ext2_find_entry(dir, child, &page);
-       if (IS_ERR_OR_NULL(de))
+       if (IS_ERR(de))
                return PTR_ERR(de);
 
        *ino = le32_to_cpu(de->inode);

diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 9a6ab213bc4df740cac46a5bccb69e458d317129..5bf2c145643b839fe5f05df0ee61bd16b82475e1 100644 (file)
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -56,17 +56,18 @@ static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
 static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
 {
        struct inode * inode;
-       ino_t ino = 0;
+       ino_t ino;
        int res;
        
        if (dentry->d_name.len > EXT2_NAME_LEN)
                return ERR_PTR(-ENAMETOOLONG);
 
        res = ext2_inode_by_name(dir, &dentry->d_name, &ino);
-       if (res)
-               return ERR_PTR(res);
-       inode = NULL;
-       if (ino) {
+       if (res) {
+               if (res != -ENOENT)
+                       return ERR_PTR(res);
+               inode = NULL;
+       } else {
                inode = ext2_iget(dir->i_sb, ino);
                if (inode == ERR_PTR(-ESTALE)) {
                        ext2_error(dir->i_sb, __func__,
@@ -81,14 +82,13 @@ static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, uns
 struct dentry *ext2_get_parent(struct dentry *child)
 {
        struct qstr dotdot = QSTR_INIT("..", 2);
-       ino_t ino = 0;
+       ino_t ino;
        int res;
 
        res = ext2_inode_by_name(d_inode(child), &dotdot, &ino);
        if (res)
                return ERR_PTR(res);
-       if (!ino)
-               return ERR_PTR(-ENOENT);
+
        return d_obtain_alias(ext2_iget(child->d_sb, ino));
 } 
 
@@ -287,10 +287,6 @@ static int ext2_unlink(struct inode * dir, struct dentry *dentry)
                err = PTR_ERR(de);
                goto out;
        }
-       if (!de) {
-               err = -ENOENT;
-               goto out;
-       }
 
        err = ext2_delete_entry (de, page);
        if (err)
@@ -347,10 +343,6 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
                err = PTR_ERR(old_de);
                goto out;
        }
-       if (!old_de) {
-               err = -ENOENT;
-               goto out;
-       }
 
        if (S_ISDIR(old_inode->i_mode)) {
                err = -EIO;
@@ -367,14 +359,11 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
                if (dir_de && !ext2_empty_dir (new_inode))
                        goto out_dir;
 
-               err = -ENOENT;
                new_de = ext2_find_entry(new_dir, &new_dentry->d_name, &new_page);
                if (IS_ERR(new_de)) {
                        err = PTR_ERR(new_de);
                        goto out_dir;
                }
-               if (!new_de)
-                       goto out_dir;
                ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
                new_inode->i_ctime = current_time(new_inode);
                if (dir_de)