Merge tag 'md/4.4' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Two major components to this update.

   1) The clustered-raid1 support from SUSE is nearly complete.  There
      are a few outstanding issues being worked on.  Maybe half a dozen
      patches will bring this to a usable state.

   2) The first stage of journalled-raid5 support from Facebook makes an
      appearance.  With a journal device configured (typically NVRAM or
      SSD), the "RAID5 write hole" should be closed - a crash during
      degraded operations cannot result in data corruption.

      The next stage will be to use the journal as a write-behind cache
      so that latency can be reduced and in some cases throughput
      increased by performing more full-stripe writes.

* tag 'md/4.4' of git://neil.brown.name/md: (66 commits)
  MD: when RAID journal is missing/faulty, block RESTART_ARRAY_RW
  MD: set journal disk ->raid_disk
  MD: kick out journal disk if it's not fresh
  raid5-cache: start raid5 readonly if journal is missing
  MD: add new bit to indicate raid array with journal
  raid5-cache: IO error handling
  raid5: journal disk can't be removed
  raid5-cache: add trim support for log
  MD: fix info output for journal disk
  raid5-cache: use bio chaining
  raid5-cache: small log->seq cleanup
  raid5-cache: new helper: r5_reserve_log_entry
  raid5-cache: inline r5l_alloc_io_unit into r5l_new_meta
  raid5-cache: take rdev->data_offset into account early on
  raid5-cache: refactor bio allocation
  raid5-cache: clean up r5l_get_meta
  raid5-cache: simplify state machine when caches flushes are not needed
  raid5-cache: factor out a helper to run all stripes for an I/O unit
  raid5-cache: rename flushed_ios to finished_ios
  raid5-cache: free I/O units earlier
  ...

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 828c2925e68f..a415e1cd39b8 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -223,6 +223,9 @@ struct stripe_head {
 	struct stripe_head	*batch_head; /* protected by stripe lock */
 	spinlock_t		batch_lock; /* only header's lock is useful */
 	struct list_head	batch_list; /* protected by head's batch lock*/
+
+	struct r5l_io_unit	*log_io;
+	struct list_head	log_list;
 	/**
 	 * struct stripe_operations
 	 * @target - STRIPE_OP_COMPUTE_BLK target
@@ -244,6 +247,7 @@ struct stripe_head {
 		struct bio	*toread, *read, *towrite, *written;
 		sector_t	sector;			/* sector of this page */
 		unsigned long	flags;
+		u32		log_checksum;
 	} dev[1]; /* allocated with extra space depending of RAID geometry */
 };
 
@@ -268,6 +272,7 @@ struct stripe_head_state {
 	struct bio_list return_bi;
 	struct md_rdev *blocked_rdev;
 	int handle_bad_blocks;
+	int log_failed;
 };
 
 /* Flags for struct r5dev.flags */
@@ -340,6 +345,7 @@ enum {
 	STRIPE_BITMAP_PENDING,	/* Being added to bitmap, don't add
 				 * to batch yet.
 				 */
+	STRIPE_LOG_TRAPPED, /* trapped into log */
 };
 
 #define STRIPE_EXPAND_SYNC_FLAGS \
@@ -543,6 +549,7 @@ struct r5conf {
 	struct r5worker_group	*worker_groups;
 	int			group_cnt;
 	int			worker_cnt_per_group;
+	struct r5l_log		*log;
 };
 
 
@@ -609,4 +616,21 @@ static inline int algorithm_is_DDF(int layout)
 
 extern void md_raid5_kick_device(struct r5conf *conf);
 extern int raid5_set_cache_size(struct mddev *mddev, int size);
+extern sector_t raid5_compute_blocknr(struct stripe_head *sh, int i, int previous);
+extern void raid5_release_stripe(struct stripe_head *sh);
+extern sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
+				     int previous, int *dd_idx,
+				     struct stripe_head *sh);
+extern struct stripe_head *
+raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
+			int previous, int noblock, int noquiesce);
+extern int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev);
+extern void r5l_exit_log(struct r5l_log *log);
+extern int r5l_write_stripe(struct r5l_log *log, struct stripe_head *head_sh);
+extern void r5l_write_stripe_run(struct r5l_log *log);
+extern void r5l_flush_stripe_to_raid(struct r5l_log *log);
+extern void r5l_stripe_write_finished(struct stripe_head *sh);
+extern int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio);
+extern void r5l_quiesce(struct r5l_log *log, int state);
+extern bool r5l_log_disk_error(struct r5conf *conf);
 #endif