For a UDF filesystem configured with an Unallocated Space Table,
a filesystem operation that triggers an update to the table results
in on-disk corruption that prevents remounting:
udf_read_tagged: tag version 0x0000 != 0x0002 || 0x0003, block 274
For example:
1. Create a filesystem
$ mkudffs --media-type=hd --blocksize=512 --lvid=BUGTEST \
--vid=BUGTEST --fsid=BUGTEST --space=unalloctable \
/dev/mmcblk0
2. Mount it
# mount /dev/mmcblk0 /mnt
3. Create a file
$ echo "No corruption, please" > /mnt/new.file
4. Umount
# umount /mnt
5. Attempt remount
# mount /dev/mmcblk0 /mnt
This appears to be a longstanding bug caused by zero-initialization of
the Unallocated Space Entry block buffer and only partial repopulation
of required fields before writing to disk.
Commit 0adfb339fd64 ("udf: Fix unalloc space handling in udf_update_inode")
addressed one such field, but several others are required.
Signed-off-by: Steven J. Magnani <[email protected]>
---
diff -uprN a/fs/udf/inode.c b/fs/udf/inode.c
--- a/fs/udf/inode.c 2015-07-06 13:42:08.861499890 -0500
+++ b/fs/udf/inode.c 2015-07-06 13:42:18.153499469 -0500
@@ -1652,17 +1652,9 @@ static int udf_update_inode(struct inode
iinfo->i_ext.i_data, inode->i_sb->s_blocksize -
sizeof(struct unallocSpaceEntry));
use->descTag.tagIdent = cpu_to_le16(TAG_IDENT_USE);
- use->descTag.tagLocation =
- cpu_to_le32(iinfo->i_location.logicalBlockNum);
- crclen = sizeof(struct unallocSpaceEntry) +
- iinfo->i_lenAlloc - sizeof(struct tag);
- use->descTag.descCRCLength = cpu_to_le16(crclen);
- use->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)use +
- sizeof(struct tag),
- crclen));
- use->descTag.tagChecksum = udf_tag_checksum(&use->descTag);
+ crclen = sizeof(struct unallocSpaceEntry);
- goto out;
+ goto finish;
}
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_FORGET))
@@ -1782,6 +1774,8 @@ static int udf_update_inode(struct inode
efe->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EFE);
crclen = sizeof(struct extendedFileEntry);
}
+
+finish:
if (iinfo->i_strat4096) {
fe->icbTag.strategyType = cpu_to_le16(4096);
fe->icbTag.strategyParameter = cpu_to_le16(1);
@@ -1791,7 +1785,9 @@ static int udf_update_inode(struct inode
fe->icbTag.numEntries = cpu_to_le16(1);
}
- if (S_ISDIR(inode->i_mode))
+ if (iinfo->i_use)
+ fe->icbTag.fileType = ICBTAG_FILE_TYPE_USE;
+ else if (S_ISDIR(inode->i_mode))
fe->icbTag.fileType = ICBTAG_FILE_TYPE_DIRECTORY;
else if (S_ISREG(inode->i_mode))
fe->icbTag.fileType = ICBTAG_FILE_TYPE_REGULAR;
@@ -1828,7 +1824,6 @@ static int udf_update_inode(struct inode
crclen));
fe->descTag.tagChecksum = udf_tag_checksum(&fe->descTag);
-out:
set_buffer_uptodate(bh);
unlock_buffer(bh);
On Tue 07-07-15 13:06:05, Steven J. Magnani wrote:
> For a UDF filesystem configured with an Unallocated Space Table,
> a filesystem operation that triggers an update to the table results
> in on-disk corruption that prevents remounting:
>
> udf_read_tagged: tag version 0x0000 != 0x0002 || 0x0003, block 274
>
> For example:
> 1. Create a filesystem
> $ mkudffs --media-type=hd --blocksize=512 --lvid=BUGTEST \
> --vid=BUGTEST --fsid=BUGTEST --space=unalloctable \
> /dev/mmcblk0
>
> 2. Mount it
> # mount /dev/mmcblk0 /mnt
>
> 3. Create a file
> $ echo "No corruption, please" > /mnt/new.file
>
> 4. Umount
> # umount /mnt
>
> 5. Attempt remount
> # mount /dev/mmcblk0 /mnt
>
> This appears to be a longstanding bug caused by zero-initialization of
> the Unallocated Space Entry block buffer and only partial repopulation
> of required fields before writing to disk.
>
> Commit 0adfb339fd64 ("udf: Fix unalloc space handling in udf_update_inode")
> addressed one such field, but several others are required.
>
> Signed-off-by: Steven J. Magnani <[email protected]>
So the patch looks good to me. But what kind of mkudffs are you using?
Because when I use the command you wrote into the changelog, I cannot mount
the filesystem. The kernel complains about:
UDF-fs: error (device ubdb): udf_read_inode: (ino 274) failed ident=256
mount: /dev/ubdb: can't read superblock
Now ident 256 is TAG_IDENT_FSD (file set descriptor). So apparently my
mkudffs doesn't create proper partition table with your parameters...
Honza
> ---
> diff -uprN a/fs/udf/inode.c b/fs/udf/inode.c
> --- a/fs/udf/inode.c 2015-07-06 13:42:08.861499890 -0500
> +++ b/fs/udf/inode.c 2015-07-06 13:42:18.153499469 -0500
> @@ -1652,17 +1652,9 @@ static int udf_update_inode(struct inode
> iinfo->i_ext.i_data, inode->i_sb->s_blocksize -
> sizeof(struct unallocSpaceEntry));
> use->descTag.tagIdent = cpu_to_le16(TAG_IDENT_USE);
> - use->descTag.tagLocation =
> - cpu_to_le32(iinfo->i_location.logicalBlockNum);
> - crclen = sizeof(struct unallocSpaceEntry) +
> - iinfo->i_lenAlloc - sizeof(struct tag);
> - use->descTag.descCRCLength = cpu_to_le16(crclen);
> - use->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)use +
> - sizeof(struct tag),
> - crclen));
> - use->descTag.tagChecksum = udf_tag_checksum(&use->descTag);
> + crclen = sizeof(struct unallocSpaceEntry);
>
> - goto out;
> + goto finish;
> }
>
> if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_FORGET))
> @@ -1782,6 +1774,8 @@ static int udf_update_inode(struct inode
> efe->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EFE);
> crclen = sizeof(struct extendedFileEntry);
> }
> +
> +finish:
> if (iinfo->i_strat4096) {
> fe->icbTag.strategyType = cpu_to_le16(4096);
> fe->icbTag.strategyParameter = cpu_to_le16(1);
> @@ -1791,7 +1785,9 @@ static int udf_update_inode(struct inode
> fe->icbTag.numEntries = cpu_to_le16(1);
> }
>
> - if (S_ISDIR(inode->i_mode))
> + if (iinfo->i_use)
> + fe->icbTag.fileType = ICBTAG_FILE_TYPE_USE;
> + else if (S_ISDIR(inode->i_mode))
> fe->icbTag.fileType = ICBTAG_FILE_TYPE_DIRECTORY;
> else if (S_ISREG(inode->i_mode))
> fe->icbTag.fileType = ICBTAG_FILE_TYPE_REGULAR;
> @@ -1828,7 +1824,6 @@ static int udf_update_inode(struct inode
> crclen));
> fe->descTag.tagChecksum = udf_tag_checksum(&fe->descTag);
>
> -out:
> set_buffer_uptodate(bh);
> unlock_buffer(bh);
>
--
Jan Kara <[email protected]>
SUSE Labs, CR
On 07/09/2015 10:16 AM, Jan Kara wrote:
> On Tue 07-07-15 13:06:05, Steven J. Magnani wrote:
>> For a UDF filesystem configured with an Unallocated Space Table,
>> a filesystem operation that triggers an update to the table results
>> in on-disk corruption that prevents remounting:
>>
>> udf_read_tagged: tag version 0x0000 != 0x0002 || 0x0003, block 274
>>
>> For example:
>> 1. Create a filesystem
>> $ mkudffs --media-type=hd --blocksize=512 --lvid=BUGTEST \
>> --vid=BUGTEST --fsid=BUGTEST --space=unalloctable \
>> /dev/mmcblk0
>>
>> 2. Mount it
>> # mount /dev/mmcblk0 /mnt
>>
>> ...
> So the patch looks good to me. But what kind of mkudffs are you using?
> Because when I use the command you wrote into the changelog, I cannot mount
> the filesystem. The kernel complains about:
>
> UDF-fs: error (device ubdb): udf_read_inode: (ino 274) failed ident=256
> mount: /dev/ubdb: can't read superblock
>
> Now ident 256 is TAG_IDENT_FSD (file set descriptor). So apparently my
> mkudffs doesn't create proper partition table with your parameters...
>
>
It identifies itself as:
mkudffs 1.0.0b2 for UDF FS 1.0.0-cvs, 2002/02/09
...from Ubuntu udftools 1.0.0b3-14.2.
------------------------------------------------------------------------
Steven J. Magnani "I claim this network for MARS!
http://www.digidescorp.com Earthling, return my space modulator!"
#include <standard.disclaimer>
On Thu 09-07-15 13:20:27, Steve Magnani wrote:
>
>
> On 07/09/2015 10:16 AM, Jan Kara wrote:
> >On Tue 07-07-15 13:06:05, Steven J. Magnani wrote:
> >>For a UDF filesystem configured with an Unallocated Space Table,
> >>a filesystem operation that triggers an update to the table results
> >>in on-disk corruption that prevents remounting:
> >>
> >> udf_read_tagged: tag version 0x0000 != 0x0002 || 0x0003, block 274
> >>
> >>For example:
> >> 1. Create a filesystem
> >> $ mkudffs --media-type=hd --blocksize=512 --lvid=BUGTEST \
> >> --vid=BUGTEST --fsid=BUGTEST --space=unalloctable \
> >> /dev/mmcblk0
> >>
> >> 2. Mount it
> >> # mount /dev/mmcblk0 /mnt
> >>
> >>...
> >So the patch looks good to me. But what kind of mkudffs are you using?
> >Because when I use the command you wrote into the changelog, I cannot mount
> >the filesystem. The kernel complains about:
> >
> >UDF-fs: error (device ubdb): udf_read_inode: (ino 274) failed ident=256
> >mount: /dev/ubdb: can't read superblock
> >
> >Now ident 256 is TAG_IDENT_FSD (file set descriptor). So apparently my
> >mkudffs doesn't create proper partition table with your parameters...
> >
> >
> It identifies itself as:
> mkudffs 1.0.0b2 for UDF FS 1.0.0-cvs, 2002/02/09
>
> ...from Ubuntu udftools 1.0.0b3-14.2.
OK, I've fixed my mkudffs and verified that your patch indeed fixes the
problem. Thanks. I have merged the patch to my tree and will push it to
Linus.
Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR