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:
+ }$
```
--
Thanks,
Jeffle
