On Fri, Sep 07, 2018 at 02:16:24PM +0800, Qu Wenruo wrote:
[BUG] fstrim on some btrfs only trims the unallocated space, not trimming any space in existing block groups.
[CAUSE] Before fstrim_range passed to btrfs_trim_fs(), it get truncated to range [0, super->total_bytes). So later btrfs_trim_fs() will only be able to trim block groups in range [0, super->total_bytes).
While for btrfs, any bytenr aligned to sector size is valid, since btrfs use its logical address space, there is nothing limiting the location where we put block groups.
For btrfs with routine balance, it's quite easy to relocate all block groups and bytenr of block groups will start beyond super->total_bytes.
In that case, btrfs will not trim existing block groups.
[FIX] Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs() can get the unmodified range, which is normally set to [0, U64_MAX].
Reported-by: Chris Murphy lists@colorremedies.com Fixes: f4c697e6406d ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Qu Wenruo wqu@suse.com
Reviewed-by: David Sterba dsterba@suse.com