Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752574AbbGIPQS (ORCPT ); Thu, 9 Jul 2015 11:16:18 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57852 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750998AbbGIPQJ (ORCPT ); Thu, 9 Jul 2015 11:16:09 -0400 Date: Thu, 9 Jul 2015 17:16:03 +0200 From: Jan Kara To: "Steven J. Magnani" Cc: jack@suse.cz, linux-kernel@vger.kernel.org, "Steven J. Magnani" Subject: Re: [PATCH] udf: Don't corrupt unalloc spacetable when writing it Message-ID: <20150709151603.GI2900@quack.suse.cz> References: <1436292365-4395-1-git-send-email-steve@digidescorp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436292365-4395-1-git-send-email-steve@digidescorp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3821 Lines: 106 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 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 SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/