ext4: ext4_search_dir should return a proper error

ext4_search_dir currently returns -1 in case of a failure, while it returns
0 when the name is not found. In such failure cases, it should return an
error code instead.

This becomes even more important when ext4_find_inline_entry returns an
error code as well in the next commit.

-EFSCORRUPTED seems appropriate as such error code as these failures would
be caused by unexpected record lengths and is in line with other instances
of ext4_check_dir_entry failures.

In the case of ext4_dx_find_entry, the current use of ERR_BAD_DX_DIR was
left as is to reduce the risk of regressions.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://patch.msgid.link/20240821152324.3621860-2-cascardo@igalia.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 1de1c1b460a768d45dd61a013f1d54606fe9e86e..7a659a31f837663afdfd43dcbfcbec878ab256a7 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1482,7 +1482,7 @@ static bool ext4_match(struct inode *parent,
 }
 
 /*
- * Returns 0 if not found, -1 on failure, and 1 on success
+ * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
  */
 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
                    struct inode *dir, struct ext4_filename *fname,
@@ -1503,7 +1503,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
                         * a full check */
                        if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
                                                 buf_size, offset))
-                               return -1;
+                               return -EFSCORRUPTED;
                        *res_dir = de;
                        return 1;
                }
@@ -1511,7 +1511,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
                de_len = ext4_rec_len_from_disk(de->rec_len,
                                                dir->i_sb->s_blocksize);
                if (de_len <= 0)
-                       return -1;
+                       return -EFSCORRUPTED;
                offset += de_len;
                de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
        }
@@ -1663,8 +1663,10 @@ restart:
                        goto cleanup_and_exit;
                } else {
                        brelse(bh);
-                       if (i < 0)
+                       if (i < 0) {
+                               ret = ERR_PTR(i);
                                goto cleanup_and_exit;
+                       }
                }
        next:
                if (++block >= nblocks)
@@ -1758,7 +1760,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
                if (retval == 1)
                        goto success;
                brelse(bh);
-               if (retval == -1) {
+               if (retval < 0) {
                        bh = ERR_PTR(ERR_BAD_DX_DIR);
                        goto errout;
                }