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>

1 files changed, 6 insertions, 6 deletions

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index f612bef98315..145a9c0c972d 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -67,7 +67,7 @@ int ext4_check_dir_entry (const char * function, struct inode * dir,
                           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 @@ revalidate:
                                  * 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 @@ revalidate:
                                 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 @@ revalidate:
                                         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);