On Sat, Mar 20, 2010 at 02:38:51PM +0300, Dan Carpenter wrote:
> Hi Chris,
>
> There is a locking problem in
> 940100a4a7b78 "Btrfs: be more selective in the defrag ioctl"
>
> There are two places where we break out of the while loop under the
> lock.
>
> fs/btrfs/ioctl.c +708 btrfs_defrag_file(159) error: double lock 'mutex:&inode->i_mutex'
> 600 mutex_lock(&inode->i_mutex);
> 601 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
> 602 BTRFS_I(inode)->force_compress = 1;
> 603
> 604 ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
> 605 if (ret) {
> 606 ret = -ENOSPC;
> 607 break;
>
> Here.
>
> 608 }
> 609
> 610 ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
> 611 if (ret) {
> 612 btrfs_free_reserved_data_space(root, inode,
> 613 PAGE_CACHE_SIZE);
> 614 ret = -ENOSPC;
> 615 break;
>
> And here.
>
> 616 }
>
> Maybe we should have "goto err_reservations;" instead of break? I
> don't know the code well enough to say.
No, everything is accounted for correctly. If the metadata reservation fails,
we free the data space reservation and break. If the data space reservation
fails, we're good to go and can just exit. Thanks,
Josef
--
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
