On Wed, 14 Sep 2011, Li Zefan wrote: > 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 <lizf@xxxxxxxxxxxxxx> Looks good to me. Reviewed-by: Sage Weil <sage@xxxxxxxxxxxx> > --- > fs/btrfs/ioctl.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 970977a..dc82bbb 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -2177,6 +2177,11 @@ 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; > -- 1.7.3.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
