From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Sun, 13 Jun 2021 21:07:18 +0000 (-0400)
Subject: bcachefs: Add an option for whether inodes use the key cache
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=996fb577fdff69b1e5a72d7ca0f152ff7bb42bc8;p=users%2Fjedix%2Flinux-maple.git

bcachefs: Add an option for whether inodes use the key cache

We probably don't ever want to flip this off in production, but it may
be useful for certain kinds of testing.

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

diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 24853bd8923b..e6be594fd0be 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -1350,6 +1350,7 @@ LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,	struct bch_sb, flags[2],  4, 64);
 LE64_BITMASK(BCH_SB_ERASURE_CODE,	struct bch_sb, flags[3],  0, 16);
 LE64_BITMASK(BCH_SB_METADATA_TARGET,	struct bch_sb, flags[3], 16, 28);
 LE64_BITMASK(BCH_SB_SHARD_INUMS,	struct bch_sb, flags[3], 28, 29);
+LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
 
 /*
  * Features:
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 565aebba30e6..8c6627907431 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -300,8 +300,10 @@ struct btree_iter *bch2_inode_peek(struct btree_trans *trans,
 	struct bkey_s_c k;
 	int ret;
 
-	iter = bch2_trans_get_iter(trans, BTREE_ID_inodes, POS(0, inum),
-				   BTREE_ITER_CACHED|flags);
+	if (trans->c->opts.inodes_use_key_cache)
+		flags |= BTREE_ITER_CACHED;
+
+	iter = bch2_trans_get_iter(trans, BTREE_ID_inodes, POS(0, inum), flags);
 	k = bch2_btree_iter_peek_slot(iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -577,8 +579,12 @@ int bch2_inode_rm(struct bch_fs *c, u64 inode_nr, bool cached)
 	struct bpos end = POS(inode_nr + 1, 0);
 	struct bch_inode_unpacked inode_u;
 	struct bkey_s_c k;
+	unsigned iter_flags = BTREE_ITER_INTENT;
 	int ret;
 
+	if (cached && c->opts.inodes_use_key_cache)
+		iter_flags |= BTREE_ITER_CACHED;
+
 	bch2_trans_init(&trans, c, 0, 1024);
 
 	/*
@@ -600,11 +606,8 @@ int bch2_inode_rm(struct bch_fs *c, u64 inode_nr, bool cached)
 retry:
 	bch2_trans_begin(&trans);
 
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_inodes, POS(0, inode_nr),
-				   (cached
-				    ? BTREE_ITER_CACHED
-				    : BTREE_ITER_SLOTS)|
-				   BTREE_ITER_INTENT);
+	iter = bch2_trans_get_iter(&trans, BTREE_ID_inodes,
+				   POS(0, inode_nr), iter_flags);
 	k = bch2_btree_iter_peek_slot(iter);
 
 	ret = bkey_err(k);
diff --git a/fs/bcachefs/opts.h b/fs/bcachefs/opts.h
index 707659e31893..2cba0e137b58 100644
--- a/fs/bcachefs/opts.h
+++ b/fs/bcachefs/opts.h
@@ -173,6 +173,11 @@ enum opt_type {
 	  OPT_BOOL(),							\
 	  BCH_SB_SHARD_INUMS,		false,				\
 	  NULL,		"Shard new inode numbers by CPU id")		\
+	x(inodes_use_key_cache,	u8,					\
+	  OPT_FORMAT|OPT_MOUNT,						\
+	  OPT_BOOL(),							\
+	  BCH_SB_INODES_USE_KEY_CACHE,	true,				\
+	  NULL,		"Use the btree key cache for the inodes btree")	\
 	x(gc_reserve_percent,		u8,				\
 	  OPT_FORMAT|OPT_MOUNT|OPT_RUNTIME,				\
 	  OPT_UINT(5, 21),						\