diff options
Diffstat (limited to 'drivers/md/dm-table.c')
| -rw-r--r-- | drivers/md/dm-table.c | 61 |
1 files changed, 57 insertions, 4 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index f90069029aae..100368eb7991 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1212,6 +1212,41 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) return &t->targets[(KEYS_PER_NODE * n) + k]; } +static int count_device(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + unsigned *num_devices = data; + + (*num_devices)++; + + return 0; +} + +/* + * Check whether a table has no data devices attached using each + * target's iterate_devices method. + * Returns false if the result is unknown because a target doesn't + * support iterate_devices. + */ +bool dm_table_has_no_data_devices(struct dm_table *table) +{ + struct dm_target *uninitialized_var(ti); + unsigned i = 0, num_devices = 0; + + while (i < dm_table_get_num_targets(table)) { + ti = dm_table_get_target(table, i++); + + if (!ti->type->iterate_devices) + return false; + + ti->type->iterate_devices(ti, count_device, &num_devices); + if (num_devices) + return false; + } + + return true; +} + /* * Establish the new table's queue_limits and validate them. */ @@ -1354,17 +1389,25 @@ static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, return q && blk_queue_nonrot(q); } -static bool dm_table_is_nonrot(struct dm_table *t) +static int device_is_not_random(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_add_random(q); +} + +static bool dm_table_all_devices_attribute(struct dm_table *t, + iterate_devices_callout_fn func) { struct dm_target *ti; unsigned i = 0; - /* Ensure that all underlying device are non-rotational. */ 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, device_is_nonrot, NULL)) + !ti->type->iterate_devices(ti, func, NULL)) return 0; } @@ -1396,7 +1439,8 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, if (!dm_table_discard_zeroes_data(t)) q->limits.discard_zeroes_data = 0; - if (dm_table_is_nonrot(t)) + /* 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 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q); @@ -1404,6 +1448,15 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, dm_table_set_integrity(t); /* + * Determine whether or not this queue's I/O timings contribute + * to the entropy pool, Only request-based targets use this. + * 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)) + queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q); + + /* * QUEUE_FLAG_STACKABLE must be set after all queue settings are * visible to other CPUs because, once the flag is set, incoming bios * are processed by request-based dm, which refers to the queue |