Linux-libre 4.4-gnupck-4.4-gnu

1 files changed, 76 insertions, 17 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index aaadee096..f52c72a1a 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -268,7 +268,7 @@ xlog_grant_head_wait(
 		__set_current_state(TASK_UNINTERRUPTIBLE);
 		spin_unlock(&head->lock);
 
-		XFS_STATS_INC(xs_sleep_logspace);
+		XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
 
 		trace_xfs_log_grant_sleep(log, tic);
 		schedule();
@@ -379,7 +379,7 @@ xfs_log_regrant(
 	if (XLOG_FORCED_SHUTDOWN(log))
 		return -EIO;
 
-	XFS_STATS_INC(xs_try_logspace);
+	XFS_STATS_INC(mp, xs_try_logspace);
 
 	/*
 	 * This is a new transaction on the ticket, so we need to change the
@@ -448,7 +448,7 @@ xfs_log_reserve(
 	if (XLOG_FORCED_SHUTDOWN(log))
 		return -EIO;
 
-	XFS_STATS_INC(xs_try_logspace);
+	XFS_STATS_INC(mp, xs_try_logspace);
 
 	ASSERT(*ticp == NULL);
 	tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
@@ -1768,7 +1768,7 @@ xlog_sync(
 	int		v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
 	int		size;
 
-	XFS_STATS_INC(xs_log_writes);
+	XFS_STATS_INC(log->l_mp, xs_log_writes);
 	ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
 
 	/* Add for LR header */
@@ -1805,7 +1805,7 @@ xlog_sync(
 	bp = iclog->ic_bp;
 	XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
 
-	XFS_STATS_ADD(xs_log_blocks, BTOBB(count));
+	XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
 
 	/* Do we need to split this write into 2 parts? */
 	if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
@@ -2422,11 +2422,20 @@ xlog_write(
 						     &partial_copy_len);
 			xlog_verify_dest_ptr(log, ptr);
 
-			/* copy region */
+			/*
+			 * Copy region.
+			 *
+			 * Unmount records just log an opheader, so can have
+			 * empty payloads with no data region to copy. Hence we
+			 * only copy the payload if the vector says it has data
+			 * to copy.
+			 */
 			ASSERT(copy_len >= 0);
-			memcpy(ptr, reg->i_addr + copy_off, copy_len);
-			xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len);
-
+			if (copy_len > 0) {
+				memcpy(ptr, reg->i_addr + copy_off, copy_len);
+				xlog_write_adv_cnt(&ptr, &len, &log_offset,
+						   copy_len);
+			}
 			copy_len += start_rec_copy + sizeof(xlog_op_header_t);
 			record_cnt++;
 			data_cnt += contwr ? copy_len : 0;
@@ -2913,7 +2922,7 @@ restart:
 
 	iclog = log->l_iclog;
 	if (iclog->ic_state != XLOG_STATE_ACTIVE) {
-		XFS_STATS_INC(xs_log_noiclogs);
+		XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
 
 		/* Wait for log writes to have flushed */
 		xlog_wait(&log->l_flush_wait, &log->l_icloglock);
@@ -3165,11 +3174,19 @@ xlog_state_switch_iclogs(
 	}
 
 	if (log->l_curr_block >= log->l_logBBsize) {
+		/*
+		 * Rewind the current block before the cycle is bumped to make
+		 * sure that the combined LSN never transiently moves forward
+		 * when the log wraps to the next cycle. This is to support the
+		 * unlocked sample of these fields from xlog_valid_lsn(). Most
+		 * other cases should acquire l_icloglock.
+		 */
+		log->l_curr_block -= log->l_logBBsize;
+		ASSERT(log->l_curr_block >= 0);
+		smp_wmb();
 		log->l_curr_cycle++;
 		if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
 			log->l_curr_cycle++;
-		log->l_curr_block -= log->l_logBBsize;
-		ASSERT(log->l_curr_block >= 0);
 	}
 	ASSERT(iclog == log->l_iclog);
 	log->l_iclog = iclog->ic_next;
@@ -3212,7 +3229,7 @@ _xfs_log_force(
 	struct xlog_in_core	*iclog;
 	xfs_lsn_t		lsn;
 
-	XFS_STATS_INC(xs_log_force);
+	XFS_STATS_INC(mp, xs_log_force);
 
 	xlog_cil_force(log);
 
@@ -3297,7 +3314,7 @@ maybe_sleep:
 			spin_unlock(&log->l_icloglock);
 			return -EIO;
 		}
-		XFS_STATS_INC(xs_log_force_sleep);
+		XFS_STATS_INC(mp, xs_log_force_sleep);
 		xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
 		/*
 		 * No need to grab the log lock here since we're
@@ -3362,7 +3379,7 @@ _xfs_log_force_lsn(
 
 	ASSERT(lsn != 0);
 
-	XFS_STATS_INC(xs_log_force);
+	XFS_STATS_INC(mp, xs_log_force);
 
 	lsn = xlog_cil_force_lsn(log, lsn);
 	if (lsn == NULLCOMMITLSN)
@@ -3411,7 +3428,7 @@ try_again:
 			     (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
 				ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
 
-				XFS_STATS_INC(xs_log_force_sleep);
+				XFS_STATS_INC(mp, xs_log_force_sleep);
 
 				xlog_wait(&iclog->ic_prev->ic_write_wait,
 							&log->l_icloglock);
@@ -3441,7 +3458,7 @@ try_again:
 				spin_unlock(&log->l_icloglock);
 				return -EIO;
 			}
-			XFS_STATS_INC(xs_log_force_sleep);
+			XFS_STATS_INC(mp, xs_log_force_sleep);
 			xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
 			/*
 			 * No need to grab the log lock here since we're
@@ -4023,3 +4040,45 @@ xlog_iclogs_empty(
 	return 1;
 }
 
+/*
+ * Verify that an LSN stamped into a piece of metadata is valid. This is
+ * intended for use in read verifiers on v5 superblocks.
+ */
+bool
+xfs_log_check_lsn(
+	struct xfs_mount	*mp,
+	xfs_lsn_t		lsn)
+{
+	struct xlog		*log = mp->m_log;
+	bool			valid;
+
+	/*
+	 * norecovery mode skips mount-time log processing and unconditionally
+	 * resets the in-core LSN. We can't validate in this mode, but
+	 * modifications are not allowed anyways so just return true.
+	 */
+	if (mp->m_flags & XFS_MOUNT_NORECOVERY)
+		return true;
+
+	/*
+	 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
+	 * handled by recovery and thus safe to ignore here.
+	 */
+	if (lsn == NULLCOMMITLSN)
+		return true;
+
+	valid = xlog_valid_lsn(mp->m_log, lsn);
+
+	/* warn the user about what's gone wrong before verifier failure */
+	if (!valid) {
+		spin_lock(&log->l_icloglock);
+		xfs_warn(mp,
+"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
+"Please unmount and run xfs_repair (>= v4.3) to resolve.",
+			 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
+			 log->l_curr_cycle, log->l_curr_block);
+		spin_unlock(&log->l_icloglock);
+	}
+
+	return valid;
+}