Use access_extent_buffer_page() to point at btree location of inline compressed data so it can be inflated without a memcopy.
Signed-off-by: jim owens <[email protected]> Signed-off-by: jim owens <[email protected]> --- V2 fixes long line checkpatch warnings fs/btrfs/extent_io.c | 16 ++++++++++++++++ fs/btrfs/extent_io.h | 8 ++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index b177ed3..d2fc17a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3053,6 +3053,22 @@ static inline struct page *extent_buffer_page(struct extent_buffer *eb, return p; } +void access_extent_buffer_page(struct bio_vec *vec, struct extent_buffer *eb, + unsigned long start, unsigned long len) +{ + size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); + unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; + size_t offset = (start_offset + start) & + ((unsigned long)PAGE_CACHE_SIZE - 1); + + WARN_ON(start > eb->len); + WARN_ON(start + len > eb->start + eb->len); + + vec->bv_page = extent_buffer_page(eb, i); + vec->bv_offset = offset; + vec->bv_len = min(len, (PAGE_CACHE_SIZE - offset)); +} + static inline unsigned long num_extent_pages(u64 start, u64 len) { return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 36de250..6ffef5a 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -2,6 +2,7 @@ #define __EXTENTIO__ #include <linux/rbtree.h> +#include <linux/bio.h> /* bits for the extent state */ #define EXTENT_DIRTY 1 @@ -179,8 +180,8 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits, gfp_t mask); int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, - int bits, int wake, int delete, struct extent_state **cached, - gfp_t mask); + int bits, int wake, int delete, + struct extent_state **cached, gfp_t mask); int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits, gfp_t mask); int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end, @@ -300,4 +301,7 @@ int extent_clear_unlock_delalloc(struct inode *inode, struct extent_io_tree *tree, u64 start, u64 end, struct page *locked_page, unsigned long op); +extern void access_extent_buffer_page(struct bio_vec *vec, + struct extent_buffer *eb, + unsigned long start, unsigned long len); #endif -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
