From 58e8012cc12b3cdebea118981c4fd7136d52f2c7 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 8 Nov 2016 18:30:31 +0100 Subject: [PATCH] btrfs: add optimized version of eb to eb copy Using copy_extent_buffer is suitable for copying betwenn buffers from an arbitrary offset and deals with page boundaries. This is not necessary when doing a full extent_buffer-to-extent_buffer copy. We can utilize the copy_page helper as well. Signed-off-by: David Sterba --- fs/btrfs/ctree.c | 4 ++-- fs/btrfs/extent_io.c | 14 ++++++++++++++ fs/btrfs/extent_io.h | 2 ++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index be362b776138..25286a5912fc 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -260,7 +260,7 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, if (IS_ERR(cow)) return PTR_ERR(cow); - copy_extent_buffer(cow, buf, 0, 0, cow->len); + copy_extent_buffer_full(cow, buf); btrfs_set_header_bytenr(cow, cow->start); btrfs_set_header_generation(cow, trans->transid); btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); @@ -1129,7 +1129,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, /* cow is set to blocking by btrfs_init_new_buffer */ - copy_extent_buffer(cow, buf, 0, 0, cow->len); + copy_extent_buffer_full(cow, buf); btrfs_set_header_bytenr(cow, cow->start); btrfs_set_header_generation(cow, trans->transid); btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 9f8a1a331c61..d24af9dc76c7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5546,6 +5546,20 @@ void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start, } } +void copy_extent_buffer_full(struct extent_buffer *dst, + struct extent_buffer *src) +{ + int i; + unsigned num_pages; + + ASSERT(dst->len == src->len); + + num_pages = num_extent_pages(dst->start, dst->len); + for (i = 0; i < num_pages; i++) + copy_page(page_address(dst->pages[i]), + page_address(src->pages[i])); +} + void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, unsigned long dst_offset, unsigned long src_offset, unsigned long len) diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 12fe17523df2..ae64c1917d0a 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -410,6 +410,8 @@ void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb, const void *src); void write_extent_buffer(struct extent_buffer *eb, const void *src, unsigned long start, unsigned long len); +void copy_extent_buffer_full(struct extent_buffer *dst, + struct extent_buffer *src); void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, unsigned long dst_offset, unsigned long src_offset, unsigned long len); -- GitLab