path: root/extent_io.h
diff options
authorJeff Mahoney <>2017-07-25 16:51:34 -0400
committerDavid Sterba <>2017-10-06 13:41:06 +0200
commita5ce5d2198226db6e4ed8f99c6f34ef74e8567bf (patch)
tree43a226d71cca6505b800c6d32f6dfe29e11c2a84 /extent_io.h
parentad39e6252b098f62a81912dd5c97b74076a80c74 (diff)
btrfs-progs: extent-cache: actually cache extent buffers
We have the infrastructure to cache extent buffers but we don't actually do the caching. As soon as the last reference is dropped, the buffer is dropped. This patch keeps the extent buffers around until the max cache size is reached (defaults to 25% of memory) and then it drops the last 10% of the LRU to free up cache space for reallocation. The cache size is configurable (for use by e.g. lowmem) when the cache is initialized. Signed-off-by: Jeff Mahoney <> [ update codingstyle, switch total_memory to bytes ] Signed-off-by: David Sterba <>
Diffstat (limited to 'extent_io.h')
1 files changed, 4 insertions, 0 deletions
diff --git a/extent_io.h b/extent_io.h
index e6174894..17a4a829 100644
--- a/extent_io.h
+++ b/extent_io.h
@@ -75,6 +75,7 @@ struct extent_io_tree {
struct cache_tree cache;
struct list_head lru;
u64 cache_size;
+ u64 max_cache_size;
struct extent_state {
@@ -106,6 +107,8 @@ static inline void extent_buffer_get(struct extent_buffer *eb)
void extent_io_tree_init(struct extent_io_tree *tree);
+void extent_io_tree_init_cache_max(struct extent_io_tree *tree,
+ u64 max_cache_size);
void extent_io_tree_cleanup(struct extent_io_tree *tree);
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits);
int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits);
@@ -146,6 +149,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
u64 bytenr, u32 blocksize);
struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
void free_extent_buffer(struct extent_buffer *eb);
+void free_extent_buffer_nocache(struct extent_buffer *eb);
int read_extent_from_disk(struct extent_buffer *eb,
unsigned long offset, unsigned long len);
int write_extent_to_disk(struct extent_buffer *eb);