From b06660b59545f5c2a5c7f12fabaad73f9c6e2e33 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 25 Mar 2022 17:37:59 +0800 Subject: [PATCH] btrfs: replace memset with memzero_page in data checksum verification The original code resets the page to 0x1 for not apparent reason, it's been like that since the initial 2007 code added in commit 07157aacb1ec ("Btrfs: Add file data csums back in via hooks in the extent map code"). It could mean that a failed buffer can be detected from the data but that's just a guess and any value is good. Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba --- fs/btrfs/inode.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b3f2010d9df5..d16d1dc8f54c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3275,11 +3275,11 @@ static int check_data_csum(struct inode *inode, struct btrfs_bio *bbio, shash->tfm = fs_info->csum_shash; crypto_shash_digest(shash, kaddr + pgoff, len, csum); + kunmap_atomic(kaddr); if (memcmp(csum, csum_expected, csum_size)) goto zeroit; - kunmap_atomic(kaddr); return 0; zeroit: btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected, @@ -3287,9 +3287,7 @@ static int check_data_csum(struct inode *inode, struct btrfs_bio *bbio, if (bbio->device) btrfs_dev_stat_inc_and_print(bbio->device, BTRFS_DEV_STAT_CORRUPTION_ERRS); - memset(kaddr + pgoff, 1, len); - flush_dcache_page(page); - kunmap_atomic(kaddr); + memzero_page(page, pgoff, len); return -EIO; } -- GitLab