ext4: Avoid rec_len overflow with 64KB block size
With 64KB blocksize, a directory entry can have size 64KB which does not fit
into 16 bits we have for entry lenght. So we store 0xffff instead and convert
value when read from / written to disk. The patch also converts some places
to use ext4_next_entry() when we are changing them anyway.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index f612bef..145a9c0 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -67,7 +67,7 @@
unsigned long offset)
{
const char * error_msg = NULL;
- const int rlen = le16_to_cpu(de->rec_len);
+ const int rlen = ext4_rec_len_from_disk(de->rec_len);
if (rlen < EXT4_DIR_REC_LEN(1))
error_msg = "rec_len is smaller than minimal";
@@ -172,10 +172,10 @@
* least that it is non-zero. A
* failure will be detected in the
* dirent test below. */
- if (le16_to_cpu(de->rec_len) <
- EXT4_DIR_REC_LEN(1))
+ if (ext4_rec_len_from_disk(de->rec_len)
+ < EXT4_DIR_REC_LEN(1))
break;
- i += le16_to_cpu(de->rec_len);
+ i += ext4_rec_len_from_disk(de->rec_len);
}
offset = i;
filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
@@ -197,7 +197,7 @@
ret = stored;
goto out;
}
- offset += le16_to_cpu(de->rec_len);
+ offset += ext4_rec_len_from_disk(de->rec_len);
if (le32_to_cpu(de->inode)) {
/* We might block in the next section
* if the data destination is
@@ -219,7 +219,7 @@
goto revalidate;
stored ++;
}
- filp->f_pos += le16_to_cpu(de->rec_len);
+ filp->f_pos += ext4_rec_len_from_disk(de->rec_len);
}
offset = 0;
brelse (bh);