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authorDavid Sterba <dsterba@suse.com>2020-04-29 19:29:04 +0200
committerDavid Sterba <dsterba@suse.com>2020-05-25 11:25:32 +0200
commit870b388db02cac33eebe40a1cbeb056cf13e9f40 (patch)
tree92610e2454cfc6c76928cbaa02a678e0ec1a0227 /fs/btrfs
parenta31356b9e263b723d4991383efc87b71c6e87991 (diff)
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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 <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/ctree.h3
-rw-r--r--fs/btrfs/struct-funcs.c8
2 files changed, 6 insertions, 5 deletions
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; \