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 <st...@digidescorp.com>
---
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);
--
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