bcachefs: Plumb through subvolume id

To implement snapshots, we need every filesystem btree operation (every
btree operation without a subvolume) to start by looking up the
subvolume and getting the current snapshot ID, with
bch2_subvolume_get_snapshot() - then, that snapshot ID is used for doing
btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.

This patch adds those bch2_subvolume_get_snapshot() calls, and also
switches to passing around a subvol_inum instead of just an inode
number.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

1 files changed, 30 insertions, 11 deletions

diff --git a/fs/bcachefs/str_hash.h b/fs/bcachefs/str_hash.h
index c6a132b3c5bb..6418089531ad 100644
--- a/fs/bcachefs/str_hash.h
+++ b/fs/bcachefs/str_hash.h
@@ -8,6 +8,7 @@
 #include "error.h"
 #include "inode.h"
 #include "siphash.h"
+#include "subvolume.h"
 #include "super.h"
 
 #include <linux/crc32c.h>
@@ -144,16 +145,21 @@ bch2_hash_lookup(struct btree_trans *trans,
 		 struct btree_iter *iter,
 		 const struct bch_hash_desc desc,
 		 const struct bch_hash_info *info,
-		 u64 inode, const void *key,
+		 subvol_inum inum, const void *key,
 		 unsigned flags)
 {
 	struct bkey_s_c k;
+	u32 snapshot;
 	int ret;
 
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		return ret;
+
 	for_each_btree_key(trans, *iter, desc.btree_id,
-			   POS(inode, desc.hash_key(info, key)),
+			   SPOS(inum.inum, desc.hash_key(info, key), snapshot),
 			   BTREE_ITER_SLOTS|flags, k, ret) {
-		if (iter->pos.inode != inode)
+		if (iter->pos.inode != inum.inum)
 			break;
 
 		if (k.k->type == desc.key_type) {
@@ -176,15 +182,20 @@ bch2_hash_hole(struct btree_trans *trans,
 	       struct btree_iter *iter,
 	       const struct bch_hash_desc desc,
 	       const struct bch_hash_info *info,
-	       u64 inode, const void *key)
+	       subvol_inum inum, const void *key)
 {
 	struct bkey_s_c k;
+	u32 snapshot;
 	int ret;
 
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		return ret;
+
 	for_each_btree_key(trans, *iter, desc.btree_id,
-			   POS(inode, desc.hash_key(info, key)),
+			   SPOS(inum.inum, desc.hash_key(info, key), snapshot),
 			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
-		if (iter->pos.inode != inode)
+		if (iter->pos.inode != inum.inum)
 			break;
 
 		if (k.k->type != desc.key_type)
@@ -229,17 +240,25 @@ static __always_inline
 int bch2_hash_set(struct btree_trans *trans,
 		  const struct bch_hash_desc desc,
 		  const struct bch_hash_info *info,
-		  u64 inode, struct bkey_i *insert, int flags)
+		  subvol_inum inum,
+		  struct bkey_i *insert, int flags)
 {
 	struct btree_iter iter, slot = { NULL };
 	struct bkey_s_c k;
 	bool found = false;
+	u32 snapshot;
 	int ret;
 
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		return ret;
+
 	for_each_btree_key(trans, iter, desc.btree_id,
-			   POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))),
+			   SPOS(inum.inum,
+				desc.hash_bkey(info, bkey_i_to_s_c(insert)),
+				snapshot),
 			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
-		if (iter.pos.inode != inode)
+		if (iter.pos.inode != inum.inum)
 			break;
 
 		if (k.k->type == desc.key_type) {
@@ -313,12 +332,12 @@ static __always_inline
 int bch2_hash_delete(struct btree_trans *trans,
 		     const struct bch_hash_desc desc,
 		     const struct bch_hash_info *info,
-		     u64 inode, const void *key)
+		     subvol_inum inum, const void *key)
 {
 	struct btree_iter iter;
 	int ret;
 
-	ret = bch2_hash_lookup(trans, &iter, desc, info, inode, key,
+	ret = bch2_hash_lookup(trans, &iter, desc, info, inum, key,
 				BTREE_ITER_INTENT);
 	if (ret)
 		return ret;