bcache: Track dirty data by stripe

To make background writeback aware of raid5/6 stripes, we first need to
track the amount of dirty data within each stripe - we do this by
breaking up the existing sectors_dirty into per stripe atomic_ts

Signed-off-by: Kent Overstreet <koverstreet@google.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 230c3a6d9be2..b93cf56260a4 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -24,6 +24,7 @@
 #include "btree.h"
 #include "debug.h"
 #include "request.h"
+#include "writeback.h"
 
 #include <linux/slab.h>
 #include <linux/bitops.h>
@@ -1599,14 +1600,14 @@ static bool fix_overlapping_extents(struct btree *b,
                                     struct btree_iter *iter,
                                     struct btree_op *op)
 {
-        void subtract_dirty(struct bkey *k, int sectors)
+        void subtract_dirty(struct bkey *k, uint64_t offset, int sectors)
         {
-                struct bcache_device *d = b->c->devices[KEY_INODE(k)];
-
-                if (KEY_DIRTY(k) && d)
-                        atomic_long_sub(sectors, &d->sectors_dirty);
+                if (KEY_DIRTY(k))
+                        bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k),
+                                                     offset, -sectors);
         }
 
+        uint64_t old_offset;
         unsigned old_size, sectors_found = 0;
 
         while (1) {
@@ -1618,6 +1619,7 @@ static bool fix_overlapping_extents(struct btree *b,
                 if (bkey_cmp(k, &START_KEY(insert)) <= 0)
                         continue;
 
+                old_offset = KEY_START(k);
                 old_size = KEY_SIZE(k);
 
                 /*
@@ -1673,7 +1675,7 @@ static bool fix_overlapping_extents(struct btree *b,
 
                         struct bkey *top;
 
-                        subtract_dirty(k, KEY_SIZE(insert));
+                        subtract_dirty(k, KEY_START(insert), KEY_SIZE(insert));
 
                         if (bkey_written(b, k)) {
                                 /*
@@ -1720,7 +1722,7 @@ static bool fix_overlapping_extents(struct btree *b,
                         }
                 }
 
-                subtract_dirty(k, old_size - KEY_SIZE(k));
+                subtract_dirty(k, old_offset, old_size - KEY_SIZE(k));
         }
 
 check_failed:
@@ -1796,6 +1798,10 @@ static bool btree_insert_key(struct btree *b, struct btree_op *op,
 insert: shift_keys(b, m, k);
 copy:   bkey_copy(m, k);
 merged:
+        if (KEY_DIRTY(k))
+                bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k),
+                                             KEY_START(k), KEY_SIZE(k));
+
         bch_check_keys(b, "%u for %s", status, op_type(op));
 
         if (b->level && !KEY_OFFSET(k))