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)
return error;
}
+/*
+ * Check whether the head of the log points to an unmount record. In other
+ * words, determine whether the log is clean. If so, update the in-core state
+ * appropriately.
+ */
+static int
+xlog_check_unmount_rec(
+ struct xlog *log,
+ xfs_daddr_t *head_blk,
+ xfs_daddr_t *tail_blk,
+ struct xlog_rec_header *rhead,
+ xfs_daddr_t rhead_blk,
+ struct xfs_buf *bp,
+ bool *clean)
+{
+ struct xlog_op_header *op_head;
+ xfs_daddr_t umount_data_blk;
+ xfs_daddr_t after_umount_blk;
+ int hblks;
+ int error;
+ char *offset;
+
+ *clean = false;
+
+ /*
+ * Look for unmount record. If we find it, then we know there was a
+ * clean unmount. Since 'i' could be the last block in the physical
+ * log, we convert to a log block before comparing to the head_blk.
+ *
+ * Save the current tail lsn to use to pass to xlog_clear_stale_blocks()
+ * below. We won't want to clear the unmount record if there is one, so
+ * we pass the lsn of the unmount record rather than the block after it.
+ */
+ if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
+ int h_size = be32_to_cpu(rhead->h_size);
+ int h_version = be32_to_cpu(rhead->h_version);
+
+ if ((h_version & XLOG_VERSION_2) &&
+ (h_size > XLOG_HEADER_CYCLE_SIZE)) {
+ hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
+ if (h_size % XLOG_HEADER_CYCLE_SIZE)
+ hblks++;
+ } else {
+ hblks = 1;
+ }
+ } else {
+ hblks = 1;
+ }
+ after_umount_blk = rhead_blk + hblks + BTOBB(be32_to_cpu(rhead->h_len));
+ after_umount_blk = do_mod(after_umount_blk, log->l_logBBsize);
+ if (*head_blk == after_umount_blk &&
+ be32_to_cpu(rhead->h_num_logops) == 1) {
+ umount_data_blk = rhead_blk + hblks;
+ umount_data_blk = do_mod(umount_data_blk, log->l_logBBsize);
+ error = xlog_bread(log, umount_data_blk, 1, bp, &offset);
+ if (error)
+ return error;
+
+ op_head = (struct xlog_op_header *)offset;
+ if (op_head->oh_flags & XLOG_UNMOUNT_TRANS) {
+ /*
+ * Set tail and last sync so that newly written log
+ * records will point recovery to after the current
+ * unmount record.
+ */
+ xlog_assign_atomic_lsn(&log->l_tail_lsn,
+ log->l_curr_cycle, after_umount_blk);
+ xlog_assign_atomic_lsn(&log->l_last_sync_lsn,
+ log->l_curr_cycle, after_umount_blk);
+ *tail_blk = after_umount_blk;
+
+ *clean = true;
+ }
+ }
+
+ return 0;
+}
+
+static void
+xlog_set_state(
+ struct xlog *log,
+ xfs_daddr_t head_blk,
+ struct xlog_rec_header *rhead,
+ xfs_daddr_t rhead_blk,
+ bool bump_cycle)
+{
+ /*
+ * Reset log values according to the state of the log when we
+ * crashed. In the case where head_blk == 0, we bump curr_cycle
+ * one because the next write starts a new cycle rather than
+ * continuing the cycle of the last good log record. At this
+ * point we have guaranteed that all partial log records have been
+ * accounted for. Therefore, we know that the last good log record
+ * written was complete and ended exactly on the end boundary
+ * of the physical log.
+ */
+ log->l_prev_block = rhead_blk;
+ log->l_curr_block = (int)head_blk;
+ log->l_curr_cycle = be32_to_cpu(rhead->h_cycle);
+ if (bump_cycle)
+ 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));
+ xlog_assign_grant_head(&log->l_reserve_head.grant, log->l_curr_cycle,
+ BBTOB(log->l_curr_block));
+ xlog_assign_grant_head(&log->l_write_head.grant, log->l_curr_cycle,
+ BBTOB(log->l_curr_block));
+}
+
/*
* Find the sync block number or the tail of the log.
*
xfs_daddr_t *tail_blk)
{
xlog_rec_header_t *rhead;
- xlog_op_header_t *op_head;
char *offset = NULL;
xfs_buf_t *bp;
int error;
- xfs_daddr_t umount_data_blk;
- xfs_daddr_t after_umount_blk;
xfs_daddr_t rhead_blk;
xfs_lsn_t tail_lsn;
- int hblks;
bool wrapped = false;
+ bool clean = false;
/*
* Find previous log record
*/
if ((error = xlog_find_head(log, head_blk)))
return error;
+ ASSERT(*head_blk < INT_MAX);
bp = xlog_get_bp(log, 1);
if (!bp)
}
/*
- * 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.
+ * 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);
- error = xlog_verify_head(log, head_blk, tail_blk, bp, &rhead_blk,
- &rhead, &wrapped);
- if (error)
- goto done;
+ 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));
/*
- * Reset log values according to the state of the log when we
- * crashed. In the case where head_blk == 0, we bump curr_cycle
- * one because the next write starts a new cycle rather than
- * continuing the cycle of the last good log record. At this
- * point we have guaranteed that all partial log records have been
- * accounted for. Therefore, we know that the last good log record
- * written was complete and ended exactly on the end boundary
- * of the physical log.
+ * Set the log state based on the current head record.
*/
- log->l_prev_block = rhead_blk;
- log->l_curr_block = (int)*head_blk;
- log->l_curr_cycle = be32_to_cpu(rhead->h_cycle);
- 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));
- xlog_assign_grant_head(&log->l_reserve_head.grant, log->l_curr_cycle,
- BBTOB(log->l_curr_block));
- xlog_assign_grant_head(&log->l_write_head.grant, log->l_curr_cycle,
- BBTOB(log->l_curr_block));
+ xlog_set_state(log, *head_blk, rhead, rhead_blk, wrapped);
+ tail_lsn = atomic64_read(&log->l_tail_lsn);
/*
- * Look for unmount record. If we find it, then we know there
- * was a clean unmount. Since 'i' could be the last block in
- * the physical log, we convert to a log block before comparing
- * to the head_blk.
+ * Look for an unmount record at the head of the log. This sets the log
+ * state to determine whether recovery is necessary.
+ */
+ error = xlog_check_unmount_rec(log, head_blk, tail_blk, rhead,
+ rhead_blk, bp, &clean);
+ if (error)
+ goto done;
+
+ /*
+ * Verify the log head if the log is not clean (e.g., we have anything
+ * but an unmount record at the head). This uses CRC verification to
+ * detect and trim torn writes. If discovered, CRC failures are
+ * considered torn writes and the log head is trimmed accordingly.
*
- * Save the current tail lsn to use to pass to
- * xlog_clear_stale_blocks() below. We won't want to clear the
- * unmount record if there is one, so we pass the lsn of the
- * unmount record rather than the block after it.
+ * Note that we can only run CRC verification when the log is dirty
+ * because there's no guarantee that the log data behind an unmount
+ * record is compatible with the current architecture.
*/
- if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
- int h_size = be32_to_cpu(rhead->h_size);
- int h_version = be32_to_cpu(rhead->h_version);
+ if (!clean) {
+ xfs_daddr_t orig_head = *head_blk;
- if ((h_version & XLOG_VERSION_2) &&
- (h_size > XLOG_HEADER_CYCLE_SIZE)) {
- hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
- if (h_size % XLOG_HEADER_CYCLE_SIZE)
- hblks++;
- } else {
- hblks = 1;
- }
- } else {
- hblks = 1;
- }
- after_umount_blk = rhead_blk + hblks + BTOBB(be32_to_cpu(rhead->h_len));
- after_umount_blk = do_mod(after_umount_blk, log->l_logBBsize);
- tail_lsn = atomic64_read(&log->l_tail_lsn);
- if (*head_blk == after_umount_blk &&
- be32_to_cpu(rhead->h_num_logops) == 1) {
- umount_data_blk = rhead_blk + hblks;
- umount_data_blk = do_mod(umount_data_blk, log->l_logBBsize);
- error = xlog_bread(log, umount_data_blk, 1, bp, &offset);
+ error = xlog_verify_head(log, head_blk, tail_blk, bp,
+ &rhead_blk, &rhead, &wrapped);
if (error)
goto done;
- op_head = (xlog_op_header_t *)offset;
- if (op_head->oh_flags & XLOG_UNMOUNT_TRANS) {
- /*
- * Set tail and last sync so that newly written
- * log records will point recovery to after the
- * current unmount record.
- */
- xlog_assign_atomic_lsn(&log->l_tail_lsn,
- log->l_curr_cycle, after_umount_blk);
- xlog_assign_atomic_lsn(&log->l_last_sync_lsn,
- log->l_curr_cycle, after_umount_blk);
- *tail_blk = after_umount_blk;
-
- /*
- * Note that the unmount was clean. If the unmount
- * was not clean, we need to know this to rebuild the
- * superblock counters from the perag headers if we
- * have a filesystem using non-persistent counters.
- */
- log->l_mp->m_flags |= XFS_MOUNT_WAS_CLEAN;
+ /* update in-core state again if the head changed */
+ if (*head_blk != orig_head) {
+ xlog_set_state(log, *head_blk, rhead, rhead_blk,
+ wrapped);
+ tail_lsn = atomic64_read(&log->l_tail_lsn);
+ error = xlog_check_unmount_rec(log, head_blk, tail_blk,
+ rhead, rhead_blk, bp,
+ &clean);
+ if (error)
+ goto done;
}
}
+ /*
+ * Note that the unmount was clean. If the unmount was not clean, we
+ * need to know this to rebuild the superblock counters from the perag
+ * headers if we have a filesystem using non-persistent counters.
+ */
+ if (clean)
+ log->l_mp->m_flags |= XFS_MOUNT_WAS_CLEAN;
+
/*
* Make sure that there are no blocks in front of the head
* with the same cycle number as the head. This can happen
projects / mirror_ubuntu-artful-kernel.git / blobdiff