From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id BED0829E17 for ; Tue, 21 May 2013 03:02:40 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id AB20D8F8049 for ; Tue, 21 May 2013 01:02:40 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id OinyaWjEv0sKcCb7 for ; Tue, 21 May 2013 01:02:39 -0700 (PDT) From: Dave Chinner Subject: [PATCH 10/11] xfs: fix incorrect remote symlink block count Date: Tue, 21 May 2013 18:02:09 +1000 Message-Id: <1369123330-9579-11-git-send-email-david@fromorbit.com> In-Reply-To: <1369123330-9579-1-git-send-email-david@fromorbit.com> References: <1369123330-9579-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: bpm@sgi.com From: Dave Chinner When CRCs are enabled, the number of blocks needed to hold a remote symlink on a 1k block size filesystem may be 2 instead of 1. The transaction reservation for the allocated bloks was not taking this into account and only allocating one block. hence when trying to read or invalidate such symlinks, we are mapping a hole where there should be a block and things go bad at that point. Fix the reservation to use the correct block count, clean up the block count calculation similar to the remote attribute calculation, and add a debug guard to detect when we don't write the entire symlink to disk. Signed-off-by: Dave Chinner --- fs/xfs/xfs_symlink.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c index 5f234389..195a403 100644 --- a/fs/xfs/xfs_symlink.c +++ b/fs/xfs/xfs_symlink.c @@ -56,16 +56,9 @@ xfs_symlink_blocks( struct xfs_mount *mp, int pathlen) { - int fsblocks = 0; - int len = pathlen; + int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize); - do { - fsblocks++; - len -= XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize); - } while (len > 0); - - ASSERT(fsblocks <= XFS_SYMLINK_MAPS); - return fsblocks; + return (pathlen + buflen - 1) / buflen; } static int @@ -405,7 +398,7 @@ xfs_symlink( if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version)) fs_blocks = 0; else - fs_blocks = XFS_B_TO_FSB(mp, pathlen); + fs_blocks = xfs_symlink_blocks(mp, pathlen); resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks); error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0, XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT); @@ -512,7 +505,7 @@ xfs_symlink( cur_chunk = target_path; offset = 0; for (n = 0; n < nmaps; n++) { - char *buf; + char *buf; d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock); byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount); @@ -525,9 +518,7 @@ xfs_symlink( bp->b_ops = &xfs_symlink_buf_ops; byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt); - if (pathlen < byte_cnt) { - byte_cnt = pathlen; - } + byte_cnt = min(byte_cnt, pathlen); buf = bp->b_addr; buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset, @@ -542,6 +533,7 @@ xfs_symlink( xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) - (char *)bp->b_addr); } + ASSERT(pathlen == 0); } /* -- 1.7.10.4 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs