• S
    udf: Don't corrupt unalloc spacetable when writing it · 70f19f58
    Steven J. Magnani 提交于
    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: NSteven J. Magnani <steve@digidescorp.com>
    Signed-off-by: NJan Kara <jack@suse.com>
    70f19f58
inode.c 64.9 KB