@@ -1037,23 +1037,24 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em;
- u64 len = PAGE_SIZE;
+ const u32 sectorsize = BTRFS_I(inode)->root->fs_info->sectorsize;
/*
* hopefully we have this extent in the tree already, try without
* the full extent lock
*/
read_lock(&em_tree->lock);
- em = lookup_extent_mapping(em_tree, start, len);
+ em = lookup_extent_mapping(em_tree, start, sectorsize);
read_unlock(&em_tree->lock);
if (!em) {
struct extent_state *cached = NULL;
- u64 end = start + len - 1;
+ u64 end = start + sectorsize - 1;
/* get the big lock and read metadata off disk */
lock_extent_bits(io_tree, start, end, &cached);
- em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
+ em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start,
+ sectorsize);
unlock_extent_cached(io_tree, start, end, &cached);
if (IS_ERR(em))
When testing subpage defrag support, I always find some strange inode nbytes error, after a lot of debugging, it turns out that defrag_lookup_extent() is using PAGE_SIZE as size for lookup_extent_mapping(). Since lookup_extent_mapping() is calling __lookup_extent_mapping() with @strict == 1, this means any extent map smaller than one page will be ignored, prevent subpage defrag to grab a correct extent map. There are quite some PAGE_SIZE usage in ioctl.c, but most of them are correct usages, and can be one of the following cases: - ioctl structure size check We want ioctl structure be contained inside one page. - real page opeartions There is one special case left untouched, check_defrag_in_cache(). This function will later be removed completely, thus there is not much meaning to change it now. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/ioctl.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)