kernel/linux.git/drivers/md/dm-delay.c, branch v6.1.168

dm-delay: fix a race between delay_presuspend and delay_bio

2023-12-03T06:32:11+00:00

[ Upstream commit 6fc45b6ed921dc00dfb264dc08c7d67ee63d2656 ] In delay_presuspend, we set the atomic variable may_delay and then stop the timer and flush pending bios. The intention here is to prevent the delay target from re-arming the timer again. However, this test is racy. Suppose that one thread goes to delay_bio, sees that dc->may_delay is one and proceeds; now, another thread executes delay_presuspend, it sets dc->may_delay to zero, deletes the timer and flushes pending bios. Then, the first thread continues and adds the bio to delayed->list despite the fact that dc->may_delay is false. Fix this bug by changing may_delay's type from atomic_t to bool and only access it while holding the delayed_bios_lock mutex. Note that we don't have to grab the mutex in delay_resume because there are no bios in flight at this point. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

dm: change "unsigned" to "unsigned int"

2023-04-13T14:55:17+00:00

[ Upstream commit 86a3238c7b9b759cb864f4f768ab2e24687dc0e6 ] Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer Stable-dep-of: f7b58a69fad9 ("dm: fix improper splitting for abnormal bios") Signed-off-by: Sasha Levin

dm: simplify basic targets

2022-05-05T21:31:35+00:00

Remove needless factoring and remap bi_sector regardless of bio_sectors() being non-zero. Signed-off-by: Mike Snitzer

dm: simplify dm_sumbit_bio_remap interface

2022-03-10T18:44:56+00:00

Remove the from_wq argument from dm_sumbit_bio_remap(). Eliminates the need for dm_sumbit_bio_remap() callers to know whether they are calling for a workqueue or from the original dm_submit_bio(). Add map_task to dm_io struct, record the map_task in alloc_io and clear it after all target ->map() calls have completed. Update dm_sumbit_bio_remap to check if 'current' matches io->map_task rather than rely on passed 'from_rq' argument. This change really simplifies the chore of porting each DM target to using dm_sumbit_bio_remap() because there is no longer the risk of programming error by not completely knowing all the different contexts a particular method that calls dm_sumbit_bio_remap() might be used in. Signed-off-by: Mike Snitzer

dm delay: use dm_submit_bio_remap

2022-02-21T20:36:34+00:00

Reviewed-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm: update target status functions to support IMA measurement

2021-08-10T17:34:23+00:00

For device mapper targets to take advantage of IMA's measurement capabilities, the status functions for the individual targets need to be updated to handle the status_type_t case for value STATUSTYPE_IMA. Update status functions for the following target types, to log their respective attributes to be measured using IMA. 01. cache 02. crypt 03. integrity 04. linear 05. mirror 06. multipath 07. raid 08. snapshot 09. striped 10. verity For rest of the targets, handle the STATUSTYPE_IMA case by setting the measurement buffer to NULL. For IMA to measure the data on a given system, the IMA policy on the system needs to be updated to have the following line, and the system needs to be restarted for the measurements to take effect. /etc/ima/ima-policy measure func=CRITICAL_DATA label=device-mapper template=ima-buf The measurements will be reflected in the IMA logs, which are located at: /sys/kernel/security/integrity/ima/ascii_runtime_measurements /sys/kernel/security/integrity/ima/binary_runtime_measurements These IMA logs can later be consumed by various attestation clients running on the system, and send them to external services for attesting the system. The DM target data measured by IMA subsystem can alternatively be queried from userspace by setting DM_IMA_MEASUREMENT_FLAG with DM_TABLE_STATUS_CMD. Signed-off-by: Tushar Sugandhi Signed-off-by: Mike Snitzer

block: rename generic_make_request to submit_bio_noacct

2020-07-01T13:27:24+00:00

generic_make_request has always been very confusingly misnamed, so rename it to submit_bio_noacct to make it clear that it is submit_bio minus accounting and a few checks. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

dm delay: fix a crash when invalid device is specified

2019-04-26T15:29:32+00:00

When the target line contains an invalid device, delay_ctr() will call delay_dtr() with NULL workqueue. Attempting to destroy the NULL workqueue causes a crash. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer

dm: Check for device sector overflow if CONFIG_LBDAF is not set

2018-12-18T14:02:26+00:00

Reference to a device in device-mapper table contains offset in sectors. If the sector_t is 32bit integer (CONFIG_LBDAF is not set), then several device-mapper targets can overflow this offset and validity check is then performed on a wrong offset and a wrong table is activated. See for example (on 32bit without CONFIG_LBDAF) this overflow: # dmsetup create test --table "0 2048 linear /dev/sdg 4294967297" # dmsetup table test 0 2048 linear 8:96 1 This patch adds explicit check for overflow if the offset is sector_t type. Signed-off-by: Milan Broz Reviewed-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm delay: add flush as a third class of IO

2018-07-27T19:24:19+00:00

Add a new class for dm-delay that delays flush requests. Previously, flushes were delayed as writes, but it caused problems if the user needed to create a device with one or a few slow sectors for the purpose of testing - all flushes would be forwarded to this device and delayed, and that skews the test results. Fix this by allowing to select 0 delay for flushes. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer