diff options
| -rw-r--r-- | fs/xfs/xfs_log_recover.c | 118 |
1 files changed, 83 insertions, 35 deletions
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 1be259044096..423c36dbcdea 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -868,6 +868,79 @@ validate_head: } /* + * Seek backwards in the log for log record headers. + * + * Given a starting log block, walk backwards until we find the provided number + * of records or hit the provided tail block. The return value is the number of + * records encountered or a negative error code. The log block and buffer + * pointer of the last record seen are returned in rblk and rhead respectively. + */ +STATIC int +xlog_rseek_logrec_hdr( + struct xlog *log, + xfs_daddr_t head_blk, + xfs_daddr_t tail_blk, + int count, + struct xfs_buf *bp, + xfs_daddr_t *rblk, + struct xlog_rec_header **rhead, + bool *wrapped) +{ + int i; + int error; + int found = 0; + char *offset = NULL; + xfs_daddr_t end_blk; + + *wrapped = false; + + /* + * Walk backwards from the head block until we hit the tail or the first + * block in the log. + */ + end_blk = head_blk > tail_blk ? tail_blk : 0; + for (i = (int) head_blk - 1; i >= end_blk; i--) { + error = xlog_bread(log, i, 1, bp, &offset); + if (error) + goto out_error; + + if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) { + *rblk = i; + *rhead = (struct xlog_rec_header *) offset; + if (++found == count) + break; + } + } + + /* + * If we haven't hit the tail block or the log record header count, + * start looking again from the end of the physical log. Note that + * callers can pass head == tail if the tail is not yet known. + */ + if (tail_blk >= head_blk && found != count) { + for (i = log->l_logBBsize - 1; i >= (int) tail_blk; i--) { + error = xlog_bread(log, i, 1, bp, &offset); + if (error) + goto out_error; + + if (*(__be32 *)offset == + cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) { + *wrapped = true; + *rblk = i; + *rhead = (struct xlog_rec_header *) offset; + if (++found == count) + break; + } + } + } + + return found; + +out_error: + return error; +} + +/* * Find the sync block number or the tail of the log. * * This will be the block number of the last record to have its @@ -898,8 +971,7 @@ xlog_find_tail( xfs_daddr_t after_umount_blk; xfs_lsn_t tail_lsn; int hblks; - - found = 0; + bool wrapped = false; /* * Find previous log record @@ -923,37 +995,16 @@ xlog_find_tail( } /* - * Search backwards looking for log record header block + * 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. */ ASSERT(*head_blk < INT_MAX); - for (i = (int)(*head_blk) - 1; i >= 0; i--) { - error = xlog_bread(log, i, 1, bp, &offset); - if (error) - goto done; - - if (*(__be32 *)offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) { - found = 1; - break; - } - } - /* - * If we haven't found the log record header block, start looking - * again from the end of the physical log. XXXmiken: There should be - * a check here to make sure we didn't search more than N blocks in - * the previous code. - */ - if (!found) { - for (i = log->l_logBBsize - 1; i >= (int)(*head_blk); i--) { - error = xlog_bread(log, i, 1, bp, &offset); - if (error) - goto done; - - if (*(__be32 *)offset == - cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) { - found = 2; - break; - } - } + found = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, bp, &i, + &rhead, &wrapped); + if (found < 0) { + error = found; + goto done; } if (!found) { xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__); @@ -961,9 +1012,6 @@ xlog_find_tail( ASSERT(0); return -EIO; } - - /* find blk_no of tail of log */ - rhead = (xlog_rec_header_t *)offset; *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn)); /* @@ -979,7 +1027,7 @@ xlog_find_tail( log->l_prev_block = i; log->l_curr_block = (int)*head_blk; log->l_curr_cycle = be32_to_cpu(rhead->h_cycle); - if (found == 2) + if (wrapped) log->l_curr_cycle++; atomic64_set(&log->l_tail_lsn, be64_to_cpu(rhead->h_tail_lsn)); atomic64_set(&log->l_last_sync_lsn, be64_to_cpu(rhead->h_lsn)); |