Before converting an inline directory to a regular directory, check
the directory entries to make sure they're not obviously broken.
This helps us to avoid a BUG_ON if one of the dirents is trashed.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/ext4/inline.c | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 645205d..c79d8e7 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1157,6 +1157,31 @@ out:
return err;
}
+static int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
+ void *buf, int buf_size)
+{
+ struct ext4_dir_entry_2 *de;
+ int nlen, rlen;
+ unsigned int offset = 0;
+ char *top;
+
+ de = (struct ext4_dir_entry_2 *)buf;
+ top = buf + buf_size;
+ while ((char *) de < top) {
+ if (ext4_check_dir_entry(dir, NULL, de, bh,
+ buf, buf_size, offset))
+ return -EIO;
+ nlen = EXT4_DIR_REC_LEN(de->name_len);
+ rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+ de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+ offset += rlen;
+ }
+ if ((char *) de > top)
+ return -EIO;
+
+ return 0;
+}
+
static int ext4_convert_inline_data_nolock(handle_t *handle,
struct inode *inode,
struct ext4_iloc *iloc)
@@ -1178,6 +1203,18 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
if (error < 0)
goto out;
+ /*
+ * Make sure the inline directory entries pass checks before we try to
+ * convert them, so that we avoid touching stuff that needs fsck.
+ */
+ if (S_ISDIR(inode->i_mode)) {
+ error = ext4_check_all_de(inode, iloc->bh,
+ buf + EXT4_INLINE_DOTDOT_SIZE,
+ inline_size - EXT4_INLINE_DOTDOT_SIZE);
+ if (error)
+ goto out;
+ }
+
error = ext4_destroy_inline_data_nolock(handle, inode);
if (error)
goto out;
--
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