From d8914002a0391331a88d9f5de4a235220735d4cc Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 27 Aug 2013 11:39:37 +1000 Subject: [PATCH] xfs: inode buffers may not be valid during recovery readahead CRC enabled filesystems fail log recovery with 100% reliability on xfstests xfs/085 with the following failure: XFS (vdb): Mounting Filesystem XFS (vdb): Starting recovery (logdev: internal) XFS (vdb): Corruption detected. Unmount and run xfs_repair XFS (vdb): bad inode magic/vsn daddr 144 #0 (magic=0) XFS: Assertion failed: 0, file: fs/xfs/xfs_inode_buf.c, line: 95 The problem is that the inode buffer has not been recovered before the readahead on the inode buffer is issued. The checkpoint being recovered actually allocates the inode chunk we are doing readahead from, so what comes from disk during readahead is essentially random and the verifier barfs on it. This inode buffer readahead problem affects non-crc filesystems, too, but xfstests does not trigger it at all on such configurations.... Signed-off-by: Dave Chinner Reviewed-by: Ben Myers Signed-off-by: Ben Myers --- fs/xfs/xfs_inode_buf.c | 36 +++++++++++++++++++++++++++++++++--- fs/xfs/xfs_inode_buf.h | 1 + fs/xfs/xfs_log_recover.c | 2 +- 3 files changed, 35 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_inode_buf.c b/fs/xfs/xfs_inode_buf.c index 38fe509827dd..e011d597f12f 100644 --- a/fs/xfs/xfs_inode_buf.c +++ b/fs/xfs/xfs_inode_buf.c @@ -61,9 +61,22 @@ xfs_inobp_check( } #endif +/* + * If we are doing readahead on an inode buffer, we might be in log recovery + * reading an inode allocation buffer that hasn't yet been replayed, and hence + * has not had the inode cores stamped into it. Hence for readahead, the buffer + * may be potentially invalid. + * + * If the readahead buffer is invalid, we don't want to mark it with an error, + * but we do want to clear the DONE status of the buffer so that a followup read + * will re-read it from disk. This will ensure that we don't get an unnecessary + * warnings during log recovery and we don't get unnecssary panics on debug + * kernels. + */ static void xfs_inode_buf_verify( - struct xfs_buf *bp) + struct xfs_buf *bp, + bool readahead) { struct xfs_mount *mp = bp->b_target->bt_mount; int i; @@ -84,6 +97,11 @@ xfs_inode_buf_verify( if (unlikely(XFS_TEST_ERROR(!di_ok, mp, XFS_ERRTAG_ITOBP_INOTOBP, XFS_RANDOM_ITOBP_INOTOBP))) { + if (readahead) { + bp->b_flags &= ~XBF_DONE; + return; + } + xfs_buf_ioerror(bp, EFSCORRUPTED); XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_HIGH, mp, dip); @@ -104,14 +122,21 @@ static void xfs_inode_buf_read_verify( struct xfs_buf *bp) { - xfs_inode_buf_verify(bp); + xfs_inode_buf_verify(bp, false); +} + +static void +xfs_inode_buf_readahead_verify( + struct xfs_buf *bp) +{ + xfs_inode_buf_verify(bp, true); } static void xfs_inode_buf_write_verify( struct xfs_buf *bp) { - xfs_inode_buf_verify(bp); + xfs_inode_buf_verify(bp, false); } const struct xfs_buf_ops xfs_inode_buf_ops = { @@ -119,6 +144,11 @@ const struct xfs_buf_ops xfs_inode_buf_ops = { .verify_write = xfs_inode_buf_write_verify, }; +const struct xfs_buf_ops xfs_inode_buf_ra_ops = { + .verify_read = xfs_inode_buf_readahead_verify, + .verify_write = xfs_inode_buf_write_verify, +}; + /* * This routine is called to map an inode to the buffer containing the on-disk diff --git a/fs/xfs/xfs_inode_buf.h b/fs/xfs/xfs_inode_buf.h index aae9fc465fe0..599e6c0ca2a9 100644 --- a/fs/xfs/xfs_inode_buf.h +++ b/fs/xfs/xfs_inode_buf.h @@ -48,5 +48,6 @@ void xfs_inobp_check(struct xfs_mount *, struct xfs_buf *); #endif /* DEBUG */ extern const struct xfs_buf_ops xfs_inode_buf_ops; +extern const struct xfs_buf_ops xfs_inode_buf_ra_ops; #endif /* __XFS_INODE_BUF_H__ */ diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index dc100fed1973..7c0c1fdc728b 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -3309,7 +3309,7 @@ xlog_recover_inode_ra_pass2( return; xfs_buf_readahead(mp->m_ddev_targp, ilfp->ilf_blkno, - ilfp->ilf_len, &xfs_inode_buf_ops); + ilfp->ilf_len, &xfs_inode_buf_ra_ops); } STATIC void