kernel.git/drivers/md/dm-clone-target.c, branch linux-5.16.y

dm: use bdev_nr_sectors and bdev_nr_bytes instead of open coding them

2021-10-18T20:43:22Z

Use the proper helpers to read the block device size. Signed-off-by: Christoph Hellwig Reviewed-by: Kees Cook Acked-by: Mike Snitzer Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de Signed-off-by: Jens Axboe

dm clone: make array 'descs' static

2021-10-12T17:54:10Z

Don't populate the read-only array descs on the stack but instead it static and add extra const. Also makes the object code smaller by 66 bytes: Before: text data bss dec hex filename 42382 11140 512 54034 d312 ./drivers/md/dm-clone-target.o After: text data bss dec hex filename 42220 11236 512 53968 d2d0 ./drivers/md/dm-clone-target.o (gcc version 11.2.0) Signed-off-by: Colin Ian King Signed-off-by: Mike Snitzer

dm: update target status functions to support IMA measurement

2021-08-10T17:34:23Z

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

dm-clone: use blkdev_issue_flush in commit_metadata

2021-01-27T16:51:48Z

Use blkdev_issue_flush instead of open coding it. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Acked-by: Damien Le Moal Signed-off-by: Jens Axboe

writeback: remove bdi->congested_fn

2020-07-08T23:20:46Z

Except for pktdvd, the only places setting congested bits are file systems that allocate their own backing_dev_info structures. And pktdvd is a deprecated driver that isn't useful in stack setup either. So remove the dead congested_fn stacking infrastructure. Signed-off-by: Christoph Hellwig Acked-by: Song Liu Acked-by: David Sterba [axboe: fixup unused variables in bcache/request.c] Signed-off-by: Jens Axboe

block: rename generic_make_request to submit_bio_noacct

2020-07-01T13:27:24Z

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 clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions()

2020-03-27T18:42:51Z

dm_clone_nr_of_hydrated_regions() returns the number of regions that have been hydrated so far. In order to do so it employs bitmap_weight(). Until now, the return type of dm_clone_nr_of_hydrated_regions() was unsigned long. Because bitmap_weight() returns an int, in case BITS_PER_LONG == 64 and the return value of bitmap_weight() is 2^31 (the maximum allowed number of regions for a device), the result is sign extended from 32 bits to 64 bits and an incorrect value is displayed, in the status output of dm-clone, as the number of hydrated regions. Fix this by having dm_clone_nr_of_hydrated_regions() return an unsigned int. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer

dm clone: Add missing casts to prevent overflows and data corruption

2020-03-27T18:42:25Z

Add missing casts when converting from regions to sectors. In case BITS_PER_LONG == 32, the lack of the appropriate casts can lead to overflows and miscalculation of the device sector. As a result, we could end up discarding and/or copying the wrong parts of the device, thus corrupting the device's data. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer

dm clone: Add overflow check for number of regions

2020-03-27T18:41:46Z

Add overflow check for clone->nr_regions variable, which holds the number of regions of the target. The overflow can occur with sufficiently large devices, if BITS_PER_LONG == 32. E.g., if the region size is 8 sectors (4K), the overflow would occur for device sizes > 34359738360 sectors (~16TB). This could result in multiple device sectors wrongly mapping to the same region number, due to the truncation from 64 bits to 32 bits, which would lead to data corruption. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer

dm clone: Fix handling of partial region discards

2020-03-27T18:41:21Z

There is a bug in the way dm-clone handles discards, which can lead to discarding the wrong blocks or trying to discard blocks beyond the end of the device. This could lead to data corruption, if the destination device indeed discards the underlying blocks, i.e., if the discard operation results in the original contents of a block to be lost. The root of the problem is the code that calculates the range of regions covered by a discard request and decides which regions to discard. Since dm-clone handles the device in units of regions, we don't discard parts of a region, only whole regions. The range is calculated as: rs = dm_sector_div_up(bio->bi_iter.bi_sector, clone->region_size); re = bio_end_sector(bio) >> clone->region_shift; , where 'rs' is the first region to discard and (re - rs) is the number of regions to discard. The bug manifests when we try to discard part of a single region, i.e., when we try to discard a block with size < region_size, and the discard request both starts at an offset with respect to the beginning of that region and ends before the end of the region. The root cause is the following comparison: if (rs == re) // skip discard and complete original bio immediately , which doesn't take into account that 'rs' might be greater than 're'. Thus, we then issue a discard request for the wrong blocks, instead of skipping the discard all together. Fix the check to also take into account the above case, so we don't end up discarding the wrong blocks. Also, add some range checks to dm_clone_set_region_hydrated() and dm_clone_cond_set_range(), which update dm-clone's region bitmap. Note that the aforementioned bug doesn't cause invalid memory accesses, because dm_clone_is_range_hydrated() returns True for this case, so the checks are just precautionary. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer