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dm table: fix iterate_devices based device capability checks

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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.

[jeffle: backport notes]
No stable writes. Also convert the no_sg_merge capability check, which
is introduced by commit 200612ec33e5 ("dm table: propagate
QUEUE_FLAG_NO_SG_MERGE"), and removed since commit 2705c93742e9 ("block:
kill QUEUE_FLAG_NO_SG_MERGE") in v5.1.

Fixes: c3c4555edd10 ("dm table: clear add_random unless all devices have it set")
Fixes: 4693c9668fdc ("dm table: propagate non rotational flag")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jeffle Xu 2021-03-09 11:20:22 +08:00 committed by Greg Kroah-Hartman
parent b2caacb95a
commit 75c5d31541
1 changed files with 53 additions and 30 deletions
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83
drivers/md/dm-table.c
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@ -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,
@ -1492,29 +1532,12 @@ static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
return q && !blk_queue_add_random(q);
}
static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
static int queue_no_sg_merge(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 && !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;
return q && test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
}
static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
@ -1607,18 +1630,18 @@ 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;
if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
else
if (dm_table_any_dev_attr(t, queue_no_sg_merge))
queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
else
queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
dm_table_verify_integrity(t);
@ -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);
/*