From 870b388db02cac33eebe40a1cbeb056cf13e9f40 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 29 Apr 2020 19:29:04 +0200 Subject: btrfs: preset set/get token with first page and drop condition All the set/get helpers first check if the token contains a cached address. After first use the address is always valid, but the extra check is done for each call. The token initialization can optimistically set it to the first extent buffer page, that we know always exists. Then the condition in all btrfs_token_*/btrfs_set_token_* can be simplified by removing the address check from the condition, but for development the assertion still makes sure it's valid. Reviewed-by: Johannes Thumshirn Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 3 ++- fs/btrfs/struct-funcs.c | 8 ++++---- 2 files changed, 6 insertions(+), 5 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index dcb82d690e76..557de0dc904a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1352,7 +1352,8 @@ static inline void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb) { token->eb = eb; - token->kaddr = NULL; + token->kaddr = page_address(eb->pages[0]); + token->offset = 0; } /* some macros to generate set/get functions for the struct fields. This diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c index cebd0b5e4f37..cef628a5a9e0 100644 --- a/fs/btrfs/struct-funcs.c +++ b/fs/btrfs/struct-funcs.c @@ -52,8 +52,8 @@ u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ u##bits res; \ \ ASSERT(token); \ - \ - if (token->kaddr && token->offset <= offset && \ + ASSERT(token->kaddr); \ + if (token->offset <= offset && \ (token->offset + PAGE_SIZE >= offset + size)) { \ kaddr = token->kaddr; \ p = kaddr + part_offset - token->offset; \ @@ -113,8 +113,8 @@ void btrfs_set_token_##bits(struct btrfs_map_token *token, \ int size = sizeof(u##bits); \ \ ASSERT(token); \ - \ - if (token->kaddr && token->offset <= offset && \ + ASSERT(token->kaddr); \ + if (token->offset <= offset && \ (token->offset + PAGE_SIZE >= offset + size)) { \ kaddr = token->kaddr; \ p = kaddr + part_offset - token->offset; \ -- cgit v1.2.3