Btrfs: Include map_type in raid_bio

Corrent code use many kinds of "clever" way to determine operation
target's raid type, as:
  raid_map != NULL
  or
  raid_map[MAX_NR] == RAID[56]_Q_STRIPE

To make code easy to maintenance, this patch put raid type into
bbio, and we can always get raid type from bbio with a "stupid"
way.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

4 files changed, 22 insertions, 18 deletions

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index cbc416204452..5264858ed768 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -994,10 +994,12 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_root *root,
         rbio->bio_pages = p + sizeof(struct page *) * num_pages;
         rbio->dbitmap = p + sizeof(struct page *) * num_pages * 2;
 
-        if (bbio->raid_map[real_stripes - 1] == RAID6_Q_STRIPE)
+        if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
+                nr_data = real_stripes - 1;
+        else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
                 nr_data = real_stripes - 2;
         else
-                nr_data = real_stripes - 1;
+                BUG();
 
         rbio->nr_data = nr_data;
         return rbio;
@@ -1850,9 +1852,7 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
                 }
 
                 /* all raid6 handling here */
-                if (rbio->bbio->raid_map[rbio->real_stripes - 1] ==
-                    RAID6_Q_STRIPE) {
-
+                if (rbio->bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) {
                         /*
                          * single failure, rebuild from parity raid5
                          * style
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index c3a98931980f..19781e924443 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1256,19 +1256,16 @@ out:
 
 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
 {
-        if (bbio->raid_map) {
-                int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
-
-                if (bbio->raid_map[real_stripes - 1] == RAID6_Q_STRIPE)
-                        return 3;
-                else
-                        return 2;
-        } else {
+        if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
+                return 2;
+        else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
+                return 3;
+        else
                 return (int)bbio->num_stripes;
-        }
 }
 
-static inline void scrub_stripe_index_and_offset(u64 logical, u64 *raid_map,
+static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
+                                                 u64 *raid_map,
                                                  u64 mapped_length,
                                                  int nstripes, int mirror,
                                                  int *stripe_index,
@@ -1276,7 +1273,7 @@ static inline void scrub_stripe_index_and_offset(u64 logical, u64 *raid_map,
 {
         int i;
 
-        if (raid_map) {
+        if (map_type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
                 /* RAID5/6 */
                 for (i = 0; i < nstripes; i++) {
                         if (raid_map[i] == RAID6_Q_STRIPE ||
@@ -1350,6 +1347,7 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
                 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
 
                 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
+
                 for (mirror_index = 0; mirror_index < nmirrors;
                      mirror_index++) {
                         struct scrub_block *sblock;
@@ -1370,7 +1368,9 @@ leave_nomem:
                         sblock->pagev[page_index] = page;
                         page->logical = logical;
 
-                        scrub_stripe_index_and_offset(logical, bbio->raid_map,
+                        scrub_stripe_index_and_offset(logical,
+                                                      bbio->map_type,
+                                                      bbio->raid_map,
                                                       mapped_length,
                                                       bbio->num_stripes -
                                                       bbio->num_tgtdevs,
@@ -1419,7 +1419,9 @@ static void scrub_bio_wait_endio(struct bio *bio, int error)
 
 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
 {
-        return page->recover && page->recover->bbio->raid_map;
+        return page->recover &&
+               (page->recover->bbio->map_type & (BTRFS_BLOCK_GROUP_RAID5 |
+               BTRFS_BLOCK_GROUP_RAID6));
 }
 
 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0843bcd6304c..8933d70c3d53 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5453,6 +5453,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
         }
 
         *bbio_ret = bbio;
+        bbio->map_type = map->type;
         bbio->num_stripes = num_stripes;
         bbio->max_errors = max_errors;
         bbio->mirror_num = mirror_num;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 4313e8ff91e5..83069dec6898 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -298,6 +298,7 @@ struct btrfs_bio {
         atomic_t refs;
         atomic_t stripes_pending;
         struct btrfs_fs_info *fs_info;
+        u64 map_type; /* get from map_lookup->type */
         bio_end_io_t *end_io;
         struct bio *orig_bio;
         unsigned long flags;