1 files changed, 30 insertions, 1 deletions

diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index ffc13c4d7e63..c9590a8e1425 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -264,6 +264,7 @@ struct stripe_head_state {
         int syncing, expanding, expanded, replacing;
         int locked, uptodate, to_read, to_write, failed, written;
         int to_fill, compute, req_compute, non_overwrite;
+        int injournal;
         int failed_num[2];
         int p_failed, q_failed;
         int dec_preread_active;
@@ -313,6 +314,11 @@ enum r5dev_flags {
                          */
         R5_Discard,     /* Discard the stripe */
         R5_SkipCopy,    /* Don't copy data from bio to stripe cache */
+        R5_InJournal,   /* data being written is in the journal device.
+                         * if R5_InJournal is set for parity pd_idx, all the
+                         * data and parity being written are in the journal
+                         * device
+                         */
 };
 
 /*
@@ -345,7 +351,23 @@ enum {
         STRIPE_BITMAP_PENDING,  /* Being added to bitmap, don't add
                                  * to batch yet.
                                  */
-        STRIPE_LOG_TRAPPED, /* trapped into log */
+        STRIPE_LOG_TRAPPED,     /* trapped into log (see raid5-cache.c)
+                                 * this bit is used in two scenarios:
+                                 *
+                                 * 1. write-out phase
+                                 *  set in first entry of r5l_write_stripe
+                                 *  clear in second entry of r5l_write_stripe
+                                 *  used to bypass logic in handle_stripe
+                                 *
+                                 * 2. caching phase
+                                 *  set in r5c_try_caching_write()
+                                 *  clear when journal write is done
+                                 *  used to initiate r5c_cache_data()
+                                 *  also used to bypass logic in handle_stripe
+                                 */
+        STRIPE_R5C_CACHING,     /* the stripe is in caching phase
+                                 * see more detail in the raid5-cache.c
+                                 */
 };
 
 #define STRIPE_EXPAND_SYNC_FLAGS \
@@ -710,4 +732,11 @@ 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);
+extern bool r5c_is_writeback(struct r5l_log *log);
+extern int
+r5c_try_caching_write(struct r5conf *conf, struct stripe_head *sh,
+                      struct stripe_head_state *s, int disks);
+extern void
+r5c_finish_stripe_write_out(struct r5conf *conf, struct stripe_head *sh,
+                            struct stripe_head_state *s);
 #endif