From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yan Zheng Subject: [PATCH] Fix csum error for compressed data Date: Mon, 10 Nov 2008 17:32:32 +0800 Message-ID: <4917FFB0.2000100@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Chris Mason , linux-btrfs@vger.kernel.org Return-path: List-ID: Hello, The decompress code doesn't take the logical offset in extent pointer into account. If the logical offset isn't zero, data will be decompressed into wrong pages. Thank you, Signed-off-by: Yan Zheng --- diff -urp 1/fs/btrfs/compression.c 2/fs/btrfs/compression.c --- 1/fs/btrfs/compression.c 2008-11-08 02:16:20.000000000 +0800 +++ 2/fs/btrfs/compression.c 2008-11-10 15:25:07.000000000 +0800 @@ -505,7 +505,6 @@ int btrfs_submit_compressed_read(struct struct block_device *bdev; struct bio *comp_bio; u64 cur_disk_byte = (u64)bio->bi_sector << 9; - u64 em_len; struct extent_map *em; int ret; @@ -524,9 +523,8 @@ int btrfs_submit_compressed_read(struct cb->errors = 0; cb->inode = inode; - cb->start = em->start; + cb->start = em->orig_start; compressed_len = em->block_len; - em_len = em->len; free_extent_map(em); cb->len = uncompressed_len; @@ -545,7 +543,7 @@ int btrfs_submit_compressed_read(struct } cb->nr_pages = nr_pages; - add_ra_bio_pages(inode, cb->start + em_len, cb); + add_ra_bio_pages(inode, em->start + em->len, cb); if (!btrfs_test_opt(root, NODATASUM) && !btrfs_test_flag(inode, NODATASUM)) { diff -urp 1/fs/btrfs/extent_map.h 2/fs/btrfs/extent_map.h --- 1/fs/btrfs/extent_map.h 2008-11-01 01:04:31.000000000 +0800 +++ 2/fs/btrfs/extent_map.h 2008-11-10 13:52:43.000000000 +0800 @@ -20,6 +20,7 @@ struct extent_map { /* all of these are in bytes */ u64 start; u64 len; + u64 orig_start; u64 block_start; u64 block_len; unsigned long flags; diff -urp 1/fs/btrfs/file.c 2/fs/btrfs/file.c --- 1/fs/btrfs/file.c 2008-11-07 19:16:08.000000000 +0800 +++ 2/fs/btrfs/file.c 2008-11-10 13:53:12.000000000 +0800 @@ -222,6 +222,7 @@ int btrfs_drop_extent_cache(struct inode em->start < start) { split->start = em->start; split->len = start - em->start; + split->orig_start = em->orig_start; split->block_start = em->block_start; if (compressed) @@ -243,6 +244,7 @@ int btrfs_drop_extent_cache(struct inode split->start = start + len; split->len = em->start + em->len - (start + len); + split->orig_start = em->orig_start; split->bdev = em->bdev; split->flags = flags; diff -urp 1/fs/btrfs/inode.c 2/fs/btrfs/inode.c --- 1/fs/btrfs/inode.c 2008-11-07 19:16:08.000000000 +0800 +++ 2/fs/btrfs/inode.c 2008-11-10 13:55:04.000000000 +0800 @@ -3949,6 +3949,8 @@ again: found_type == BTRFS_FILE_EXTENT_PREALLOC) { em->start = extent_start; em->len = extent_end - extent_start; + em->orig_start = extent_start - + btrfs_file_extent_offset(leaf, item); bytenr = btrfs_file_extent_disk_bytenr(leaf, item); if (bytenr == 0) { em->block_start = EXTENT_MAP_HOLE; @@ -3988,6 +3990,7 @@ again: em->start = extent_start + extent_offset; em->len = (copy_size + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); + em->orig_start = EXTENT_MAP_INLINE; if (compressed) set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); ptr = btrfs_file_extent_inline_start(item) + extent_offset;