From 82ff6cc26e98f9bba8e2a10f727e335fa241cc47 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Mon, 7 Mar 2016 08:22:22 +1100 Subject: [PATCH] xfs: separate log head record discovery from verification The code that locates the log record at the head of the log is buried in the log head verification function. This is fine when torn write verification occurs unconditionally, but this behavior is problematic for filesystems that might be moved across systems with different architectures. In preparation for separating examination of the log head for unmount records from torn write detection, lift the record location logic out of the log verification function and into the caller. This patch does not change behavior. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_log_recover.c | 42 +++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 22 deletions(-) diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index da37beb76f6e..c2d04ff8876b 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -1109,27 +1109,10 @@ xlog_verify_head( bool tmp_wrapped; /* - * Search backwards through the log looking for the log record header - * block. This wraps all the way back around to the head so something is - * seriously wrong if we can't find it. - */ - found = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, bp, rhead_blk, - rhead, wrapped); - if (found < 0) - return found; - if (!found) { - xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__); - return -EIO; - } - - *tail_blk = BLOCK_LSN(be64_to_cpu((*rhead)->h_tail_lsn)); - - /* - * Now that we have a tail block, check the head of the log for torn - * writes. Search again until we hit the tail or the maximum number of - * log record I/Os that could have been in flight at one time. Use a - * temporary buffer so we don't trash the rhead/bp pointer from the - * call above. + * Check the head of the log for torn writes. Search backwards from the + * head until we hit the tail or the maximum number of log record I/Os + * that could have been in flight at one time. Use a temporary buffer so + * we don't trash the rhead/bp pointers from the caller. */ tmp_bp = xlog_get_bp(log, 1); if (!tmp_bp) @@ -1254,6 +1237,7 @@ xlog_find_tail( */ if ((error = xlog_find_head(log, head_blk))) return error; + ASSERT(*head_blk < INT_MAX); bp = xlog_get_bp(log, 1); if (!bp) @@ -1270,13 +1254,27 @@ xlog_find_tail( } } + /* + * Search backwards through the log looking for the log record header + * block. This wraps all the way back around to the head so something is + * seriously wrong if we can't find it. + */ + error = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, bp, + &rhead_blk, &rhead, &wrapped); + if (error < 0) + return error; + if (!error) { + xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__); + return -EIO; + } + *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn)); + /* * Trim the head block back to skip over torn records. We can have * multiple log I/Os in flight at any time, so we assume CRC failures * back through the previous several records are torn writes and skip * them. */ - ASSERT(*head_blk < INT_MAX); error = xlog_verify_head(log, head_blk, tail_blk, bp, &rhead_blk, &rhead, &wrapped); if (error) -- 2.20.1