diff mbox

+ ext3-fix-support-for-empty-directory-blocks-in-64k-blocksize-filesystems.patch added to -mm tree

Message ID 200902102259.n1AMxMDL008883@imap1.linux-foundation.org
State Not Applicable, archived
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Commit Message

Andrew Morton Feb. 10, 2009, 10:59 p.m. UTC
The patch titled
     ext3: fix support for empty directory blocks in 64k blocksize filesystems
has been added to the -mm tree.  Its filename is
     ext3-fix-support-for-empty-directory-blocks-in-64k-blocksize-filesystems.patch

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------------------------------------------------------
Subject: ext3: fix support for empty directory blocks in 64k blocksize filesystems
From: Wei Yongjun <yjwei@cn.fujitsu.com>

The rec_len field in the directory entry is 16 bits, so if the filesystem
is completely empty, rec_len of 0 is used to designate 65536 in e2fsprogs,
for the case where the directory entry takes the entire 64k block.

But if an empty directory is read, an error message will be output by
current kernels.  You can use the following commands to reproduce it.

  - mkfs.ext3 -b $(( 64 * 1024 )) /dev/sdc1
  - mount /dev/sda1 /mnt
  - cd /mnt/lost+found
  - ll
  - tail /var/log/messages
  EXT3-fs error (device sdc1): ext3_readdir: bad entry in \
  directory #11: rec_len is smaller than minimal - offset=0, \
  inode=0, rec_len=0, name_len=0

Treat a rec_len of 0 as 65536, as e2fsprogs does.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/ext3_fs.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Theodore Ts'o Feb. 11, 2009, 3:03 p.m. UTC | #1
On Tue, Feb 10, 2009 at 02:59:22PM -0800, akpm@linux-foundation.org wrote:
> 
> The patch titled
>      ext3: fix support for empty directory blocks in 64k blocksize filesystems
> has been added to the -mm tree.  Its filename is
>      ext3-fix-support-for-empty-directory-blocks-in-64k-blocksize-filesystems.patch

NACK; I think we need to discuss this some more.  See the discussion
around the similar patch for ext4.

							- Ted
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diff mbox

Patch

diff -puN include/linux/ext3_fs.h~ext3-fix-support-for-empty-directory-blocks-in-64k-blocksize-filesystems include/linux/ext3_fs.h
--- a/include/linux/ext3_fs.h~ext3-fix-support-for-empty-directory-blocks-in-64k-blocksize-filesystems
+++ a/include/linux/ext3_fs.h
@@ -711,7 +711,7 @@  static inline unsigned ext3_rec_len_from
 {
 	unsigned len = le16_to_cpu(dlen);
 
-	if (len == EXT3_MAX_REC_LEN)
+	if (len == EXT3_MAX_REC_LEN || len == 0)
 		return 1 << 16;
 	return len;
 }
@@ -719,7 +719,7 @@  static inline unsigned ext3_rec_len_from
 static inline __le16 ext3_rec_len_to_disk(unsigned len)
 {
 	if (len == (1 << 16))
-		return cpu_to_le16(EXT3_MAX_REC_LEN);
+		return cpu_to_le16(0);
 	else if (len > (1 << 16))
 		BUG();
 	return cpu_to_le16(len);