On Sun, May 03, 2015 at 01:56:00AM +0100, Filipe Manana wrote: > Marc reported a problem where the receiving end of an incremental send > was performing clone operations that failed with -EINVAL. This happened > because, unlike for uncompressed extents, we were not checking if the > source clone offset and length, after summing the data offset, falls > within the source file's boundaries. > > So make sure we do such checks when attempting to issue clone operations > for compressed extents. > > Problem reproducible with the following steps: > > $ mkfs.btrfs -f /dev/sdb > $ mount -o compress /dev/sdb /mnt > $ mkfs.btrfs -f /dev/sdc > $ mount -o compress /dev/sdc /mnt2 > > # Create the file with a single extent of 128K. This creates a metadata file > # extent item with a data start offset of 0 and a logical length of 128K. > $ xfs_io -f -c "pwrite -S 0xaa 64K 128K" -c "fsync" /mnt/foo > > # Now rewrite the range 64K to 112K of our file. This will make the inode's > # metadata continue to point to the 128K extent we created before, but now > # with an extent item that points to the extent with a data start offset of > # 112K and a logical length of 16K. > # That metadata file extent item is associated with the logical file offset > # at 176K and covers the logical file range 176K to 192K. > $ xfs_io -c "pwrite -S 0xbb 64K 112K" -c "fsync" /mnt/foo > > # Now rewrite the range 180K to 12K. This will make the inode's metadata > # continue to point the the 128K extent we created earlier, with a single > # extent item that points to it with a start offset of 112K and a logical > # length of 4K. > # That metadata file extent item is associated with the logical file offset > # at 176K and covers the logical file range 176K to 180K. > $ xfs_io -c "pwrite -S 0xcc 180K 12K" -c "fsync" /mnt/foo > > $ btrfs subvolume snapshot -r /mnt /mnt/snap1 > > $ touch /mnt/bar > # Calls the btrfs clone ioctl. > $ ~/xfstests/src/cloner -s $((176 * 1024)) -d $((176 * 1024)) \ > -l $((4 * 1024)) /mnt/foo /mnt/bar > > $ btrfs subvolume snapshot -r /mnt /mnt/snap2 > > $ btrfs send /mnt/snap1 | btrfs receive /mnt2 > At subvol /mnt/snap1 > At subvol snap1 > > $ btrfs send -p /mnt/snap1 /mnt/snap2 | btrfs receive /mnt2 > At subvol /mnt/snap2 > At snapshot snap2 > ERROR: failed to clone extents to bar > Invalid argument > > A test case for fstests follows soon. > > Reported-by: Marc MERLIN <marc@xxxxxxxxxxx> > Tested-by: Marc MERLIN <marc@xxxxxxxxxxx> > Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> Tested-by: David Sterba <dsterba@xxxxxxx> -- 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
