From 689f9346612d96ab93890160cf2fe0df5217ab73 Mon Sep 17 00:00:00 2001 From: Yan Date: Mon, 29 Oct 2007 11:41:07 -0400 Subject: [PATCH] Fix inline extent handling in btrfs_get_extent 1. Reorder kmap and the test for 'page != NULL' 2. Zero-fill rest area of a block when inline extent isn't big enough. 3. Do not insert extent_map into the map tree when page == NULL. (If insert the extent_map into the map tree, subsequent read requests will find it in the map tree directly and the corresponding inline extent data aren't copied into page by the the get_extent function. extent_read_full_page can't handle that case) Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index c88f13a88555..0ba1cdbdf112 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1596,8 +1596,7 @@ again: size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf, path->slots[0])); - - extent_end = (extent_start + size) | + extent_end = (extent_start + size - 1) | ((u64)root->sectorsize - 1); if (start < extent_start || start >= extent_end) { em->start = start; @@ -1610,29 +1609,32 @@ again: } goto not_found_em; } + em->block_start = EXTENT_MAP_INLINE; + em->block_end = EXTENT_MAP_INLINE; + + if (!page) { + em->start = extent_start; + em->end = extent_start + size - 1; + goto out; + } extent_offset = (page->index << PAGE_CACHE_SHIFT) - - extent_start; - ptr = btrfs_file_extent_inline_start(item) + extent_offset; - map = kmap(page); + extent_start + page_offset; copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset, size - extent_offset); - - em->block_start = EXTENT_MAP_INLINE; - em->block_end = EXTENT_MAP_INLINE; em->start = extent_start + extent_offset; em->end = (em->start + copy_size -1) | ((u64)root->sectorsize -1); - - if (!page) { - goto insert; + map = kmap(page); + ptr = btrfs_file_extent_inline_start(item) + extent_offset; + read_extent_buffer(leaf, map + page_offset, ptr, copy_size); + + if (em->start + copy_size <= em->end) { + size = min_t(u64, em->end + 1 - em->start, + PAGE_CACHE_SIZE - page_offset) - copy_size; + memset(map + page_offset + copy_size, 0, size); } - read_extent_buffer(leaf, map + page_offset, ptr, copy_size); - /* - memset(map + page_offset + copy_size, 0, - PAGE_CACHE_SIZE - copy_size - page_offset); - */ flush_dcache_page(page); kunmap(page); set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS); -- 2.39.5