On 3/8/21 5:57 PM, Greg KH wrote:
> On Mon, Mar 08, 2021 at 10:16:07AM +0800, JeffleXu wrote:
>>
>>
>> On 3/7/21 11:09 PM, Greg KH wrote:
>>> On Fri, Mar 05, 2021 at 02:46:23PM +0800, Jeffle Xu wrote:
>>>> commit a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e upstream.
>>>>
>>>> According to the definition of dm_iterate_devices_fn:
>>>> * This function must iterate through each section of device used by the
>>>> * target until it encounters a non-zero return code, which it then returns.
>>>> * Returns zero if no callout returned non-zero.
>>>>
>>>> For some target type (e.g. dm-stripe), one call of iterate_devices() may
>>>> iterate multiple underlying devices internally, in which case a non-zero
>>>> return code returned by iterate_devices_callout_fn will stop the iteration
>>>> in advance. No iterate_devices_callout_fn should return non-zero unless
>>>> device iteration should stop.
>>>>
>>>> Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and
>>>> elevate it for reuse to stop iterating (and return non-zero) on the
>>>> first device that causes iterate_devices_callout_fn to return non-zero.
>>>> Use dm_table_any_dev_attr() to properly iterate through devices.
>>>>
>>>> Rename device_is_nonrot() to device_is_rotational() and invert logic
>>>> accordingly to fix improper disposition.
>>>>
>>>> Fixes: c3c4555edd10 ("dm table: clear add_random unless all devices have it set")
>>>> Fixes: 4693c9668fdc ("dm table: propagate non rotational flag")
>>>> Cc: stable@xxxxxxxxxxxxxxx
>>>> Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
>>>> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
>>>> [jeffle: no stable writes]
>>>> ---
>>>> drivers/md/dm-table.c | 71 ++++++++++++++++++++++++++++---------------
>>>> 1 file changed, 47 insertions(+), 24 deletions(-)
>>>>
>>>> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
>>>> index 5d120c3cee57..ba56be34cd5d 100644
>>>> --- a/drivers/md/dm-table.c
>>>> +++ b/drivers/md/dm-table.c
>>>> @@ -1306,6 +1306,46 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
>>>> return &t->targets[(KEYS_PER_NODE * n) + k];
>>>> }
>>>>
>>>> +/*
>>>> + * type->iterate_devices() should be called when the sanity check needs to
>>>> + * iterate and check all underlying data devices. iterate_devices() will
>>>> + * iterate all underlying data devices until it encounters a non-zero return
>>>> + * code, returned by whether the input iterate_devices_callout_fn, or
>>>> + * iterate_devices() itself internally.
>>>> + *
>>>> + * For some target type (e.g. dm-stripe), one call of iterate_devices() may
>>>> + * iterate multiple underlying devices internally, in which case a non-zero
>>>> + * return code returned by iterate_devices_callout_fn will stop the iteration
>>>> + * in advance.
>>>> + *
>>>> + * Cases requiring _any_ underlying device supporting some kind of attribute,
>>>> + * should use the iteration structure like dm_table_any_dev_attr(), or call
>>>> + * it directly. @func should handle semantics of positive examples, e.g.
>>>> + * capable of something.
>>>> + *
>>>> + * Cases requiring _all_ underlying devices supporting some kind of attribute,
>>>> + * should use the iteration structure like dm_table_supports_nowait() or
>>>> + * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
>>>> + * uses an @anti_func that handle semantics of counter examples, e.g. not
>>>> + * capable of something. So: return !dm_table_any_dev_attr(t, anti_func);
>>>> + */
>>>> +static bool dm_table_any_dev_attr(struct dm_table *t,
>>>> + iterate_devices_callout_fn func)
>>>> +{
>>>> + struct dm_target *ti;
>>>> + unsigned int i;
>>>> +
>>>> + for (i = 0; i < dm_table_get_num_targets(t); i++) {
>>>> + ti = dm_table_get_target(t, i);
>>>> +
>>>> + if (ti->type->iterate_devices &&
>>>> + ti->type->iterate_devices(ti, func, NULL))
>>>> + return true;
>>>> + }
>>>> +
>>>> + return false;
>>>> +}
>>>> +
>>>> static int count_device(struct dm_target *ti, struct dm_dev *dev,
>>>> sector_t start, sector_t len, void *data)
>>>> {
>>>> @@ -1476,12 +1516,12 @@ static bool dm_table_discard_zeroes_data(struct dm_table *t)
>>>> return true;
>>>> }
>>>>
>>>> -static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
>>>> - sector_t start, sector_t len, void *data)
>>>> +static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
>>>> + sector_t start, sector_t len, void *data)
>>>> {
>>>> struct request_queue *q = bdev_get_queue(dev->bdev);
>>>>
>>>> - return q && blk_queue_nonrot(q);
>>>> + return q && !blk_queue_nonrot(q);
>>>> }
>>>>
>>>> static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
>>>> @@ -1500,23 +1540,6 @@ static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
>>>> return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
>>>> }
>>>>
>>>> -static bool dm_table_all_devices_attribute(struct dm_table *t,
>>>> - iterate_devices_callout_fn func)
>>>> -{
>>>> - struct dm_target *ti;
>>>> - unsigned i = 0;
>>>> -
>>>> - while (i < dm_table_get_num_targets(t)) {
>>>> - ti = dm_table_get_target(t, i++);
>>>> -
>>>> - if (!ti->type->iterate_devices ||
>>>> - !ti->type->iterate_devices(ti, func, NULL))
>>>> - return false;
>>>> - }
>>>> -
>>>> - return true;
>>>> -}
>>>> -
>>>> static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
>>>> sector_t start, sector_t len, void *data)
>>>> {
>>>> @@ -1607,10 +1630,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
>>>> q->limits.discard_zeroes_data = 0;
>>>>
>>>> /* Ensure that all underlying devices are non-rotational. */
>>>> - if (dm_table_all_devices_attribute(t, device_is_nonrot))
>>>> - queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
>>>> - else
>>>> + if (dm_table_any_dev_attr(t, device_is_rotational))
>>>> queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
>>>> + else
>>>> + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
>>>>
>>>> if (!dm_table_supports_write_same(t))
>>>> q->limits.max_write_same_sectors = 0;
>>>> @@ -1628,7 +1651,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
>>>> * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
>>>> * have it set.
>>>> */
>>>> - if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
>>>> + if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random))
>>>> queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
>>>>
>>>> /*
>>>> --
>>>> 2.27.0
>>>>
>>>
>>> This patch breaks the build :(
>>>
>>> Please always test-build your patches.
>>>
>>
>> Sorry, could you please attach your fail log or steps to reproduce it? I
>> can't reproduce it with 'make allyesconfig && make' on x86.
>>
>> Though I indeed know that this patch has one style problem found by
>> checpatch.py, though it's inherited from the upstream patch...
>>
>> ```
>> ERROR:CODE_INDENT: code indent should use tabs where possible
>> #77: FILE: drivers/md/dm-table.c:1333:
>> + }$
>> ```
>
> drivers/md/dm-table.c: In function ‘dm_table_set_restrictions’:
> drivers/md/dm-table.c:1641:6: error: implicit declaration of function ‘dm_table_all_devices_attribute’ [-Werror=implicit-function-declaration]
> 1641 | if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
>
> Is the error. Try 'allmodconfig', that might provide you with more
> config options. I have attached the .config file I used to build this
> here.
Thanks. Indeed it's an error here. This error is fixed and thus hidden
by the following patch (patch 2). I only build-tested the code base
after applying all this patch set, not realizing that I should do the
build-test on a per-patch basis.
Sorry I will resend the new version after fixing this...
--
Thanks,
Jeffle
