From 0e7b824c4ef9f5bcf5e48cdce164a7b349dde969 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Sun, 18 Sep 2011 10:20:46 -0400 Subject: [PATCH] Btrfs: don't make a file partly checksummed through file clone To reproduce the bug: # mount /dev/sda7 /mnt # dd if=/dev/zero of=/mnt/src bs=4K count=1 # umount /mnt # mount -o nodatasum /dev/sda7 /mnt # dd if=/dev/zero of=/mnt/dst bs=4K count=1 # clone_range -s 4K -l 4K /mnt/src /mnt/dst # echo 3 > /proc/sys/vm/drop_caches # cat /mnt/dst # dmesg ... btrfs no csum found for inode 258 start 0 btrfs csum failed ino 258 off 0 csum 2566472073 private 0 It's because part of the file is checksummed and the other part is not, and then btrfs will complain checksum is not found when we read the file. Disallow file clone if src and dst file have different checksum flag, so we ensure a file is completely checksummed or unchecksummed. Signed-off-by: Li Zefan Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8bfb514b26c9..1e766e86f334 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2185,6 +2185,11 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, if (!(src_file->f_mode & FMODE_READ)) goto out_fput; + /* don't make the dst file partly checksummed */ + if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) != + (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) + goto out_fput; + ret = -EISDIR; if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) goto out_fput; -- 2.39.2