Messages in this thread | | | Date | Fri, 15 Sep 2023 12:03:23 +0200 (CEST) | From | Geert Uytterhoeven <> | Subject | Re: [PATCH v9 03/11] btrfs: add support for inserting raid stripe extents |
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Hi David,
On Thu, 14 Sep 2023, David Sterba wrote: > On Thu, Sep 14, 2023 at 09:06:58AM -0700, Johannes Thumshirn wrote: >> Add support for inserting stripe extents into the raid stripe tree on >> completion of every write that needs an extra logical-to-physical >> translation when using RAID. >> >> Inserting the stripe extents happens after the data I/O has completed, >> this is done to a) support zone-append and b) rule out the possibility of >> a RAID-write-hole. >> >> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>> --- /dev/null >> +++ b/fs/btrfs/raid-stripe-tree.c >> +static int btrfs_insert_striped_mirrored_raid_extents( >> + struct btrfs_trans_handle *trans, >> + struct btrfs_ordered_extent *ordered, >> + u64 map_type) >> +{ >> + struct btrfs_io_context *bioc; >> + struct btrfs_io_context *rbioc; >> + const int nstripes = list_count_nodes(&ordered->bioc_list); >> + const int index = btrfs_bg_flags_to_raid_index(map_type); >> + const int substripes = btrfs_raid_array[index].sub_stripes; >> + const int max_stripes = >> + trans->fs_info->fs_devices->rw_devices / substripes; > > This will probably warn due to u64/u32 division.
Worse, it causes link failures in linux-next, as e.g. reported by noreply@ellerman.id.au:
ERROR: modpost: "__udivdi3" [fs/btrfs/btrfs.ko] undefined!
So despite being aware of the issue, you still queued it?
The use of "int" for almost all variables is also a red flag: - list_count_nodes() returns size_t, - btrfs_bg_flags_to_raid_index() returns an enum. - btrfs_raid_array[index].sub_stripes is u8, - The result of the division may not fit in 32-bit.
Thanks for fixing, soon! ;-)
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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