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 24853bd8923b5c71bb37b764406bb2edd8517461..e6be594fd0be8100653199d8f15cd60ffe0ffbfd 100644 (file)
--- 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 565aebba30e6087e48497c75112532ca00dd5083..8c6627907431db1913f85413046febc60f2073b2 100644 (file)
--- 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 707659e31893aec47c34ed92a364ca1365f321c8..2cba0e137b58995c9016e034651de3da51779130 100644 (file)
--- 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),                                              \