diff options
author | David Sterba | 2020-04-29 23:23:37 +0200 |
---|---|---|
committer | David Sterba | 2020-05-25 11:25:33 +0200 |
commit | 5cd17f343bd1c47dc673260fa2973abc14ecc549 (patch) | |
tree | 4dc319fad6bf754e73054a0fcd529d18ad203549 /fs/btrfs | |
parent | ce7afe8782a5293edbf4bc2165ac4a866ed430db (diff) |
btrfs: speed up and simplify generic_bin_search
The bin search jumps over the extent buffer item keys, comparing
directly the bytes if the key is in one page, or storing it in a
temporary buffer in case it spans two pages.
The mapping start and length are obtained from map_private_extent_buffer,
which is heavy weight compared to what we need. We know the key size and
can find out the eb page in a simple way. For keys spanning two pages
the fallback read_extent_buffer is used.
The temporary variables are reduced and moved to the scope of use.
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.c | 43 |
1 files changed, 15 insertions, 28 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 6dbeb23c59ec..746dec22f250 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1668,15 +1668,8 @@ static noinline int generic_bin_search(struct extent_buffer *eb, { int low = 0; int high = max; - int mid; int ret; - struct btrfs_disk_key *tmp = NULL; - struct btrfs_disk_key unaligned; - unsigned long offset; - char *kaddr = NULL; - unsigned long map_start = 0; - unsigned long map_len = 0; - int err; + const int key_size = sizeof(struct btrfs_disk_key); if (low > high) { btrfs_err(eb->fs_info, @@ -1687,32 +1680,26 @@ static noinline int generic_bin_search(struct extent_buffer *eb, } while (low < high) { + unsigned long oip; + unsigned long offset; + struct btrfs_disk_key *tmp; + struct btrfs_disk_key unaligned; + int mid; + mid = (low + high) / 2; offset = p + mid * item_size; + oip = offset_in_page(offset); - if (!kaddr || offset < map_start || - (offset + sizeof(struct btrfs_disk_key)) > - map_start + map_len) { - - err = map_private_extent_buffer(eb, offset, - sizeof(struct btrfs_disk_key), - &kaddr, &map_start, &map_len); - - if (!err) { - tmp = (struct btrfs_disk_key *)(kaddr + offset - - map_start); - } else if (err == 1) { - read_extent_buffer(eb, &unaligned, - offset, sizeof(unaligned)); - tmp = &unaligned; - } else { - return err; - } + if (oip + key_size <= PAGE_SIZE) { + const unsigned long idx = offset >> PAGE_SHIFT; + char *kaddr = page_address(eb->pages[idx]); + tmp = (struct btrfs_disk_key *)(kaddr + oip); } else { - tmp = (struct btrfs_disk_key *)(kaddr + offset - - map_start); + read_extent_buffer(eb, &unaligned, offset, key_size); + tmp = &unaligned; } + ret = comp_keys(tmp, key); if (ret < 0) |