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path: root/drivers/md/dm-clone-target.c (follow)
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* block: replace fmode_t with a block-specific type for block open flagsChristoph Hellwig2023-06-121-5/+5
| | | | | | | | | | | | | | The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd] Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* dm: push error reporting down to dm_register_target()Yangtao Li2023-04-111-1/+0
| | | | | | | | Simplifies each DM target's init method by making dm_register_target() responsible for its error reporting (on behalf of targets). Signed-off-by: Yangtao Li <frank.li@vivo.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
* dm clone: call kmem_cache_destroy() in dm_clone_init() error pathMike Snitzer2023-04-041-0/+1
| | | | | | | Otherwise the _hydration_cache will leak if dm_register_target() fails. Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@kernel.org>
* dm clone: prefer kvmalloc_array()Heinz Mauelshagen2023-02-141-1/+1
| | | | | Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
* dm clone: Fix UAF in clone_dtr()Luo Meng2022-11-301-0/+1
| | | | | | | | | | | | Dm_clone also has the same UAF problem when dm_resume() and dm_destroy() are concurrent. Therefore, cancelling timer again in clone_dtr(). Cc: stable@vger.kernel.org Fixes: 7431b7835f554 ("dm: add clone target") Signed-off-by: Luo Meng <luomeng12@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
* dm clone: Fix typo in block_device format specifierNikos Tsironis2022-10-181-1/+1
| | | | | | | | | Use %pg for printing the block device name, instead of %pd. Fixes: 385411ffba0c ("dm: stop using bdevname") Cc: stable@vger.kernel.org # v5.18+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
* block: remove QUEUE_FLAG_DISCARDChristoph Hellwig2022-04-181-8/+1
| | | | | | | | | | | | | | | | | | | Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390] Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* dm: stop using bdevnameChristoph Hellwig2022-03-021-6/+4
| | | | | | | | Just use the %pg format specifier instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: use bdev_nr_sectors and bdev_nr_bytes instead of open coding themChristoph Hellwig2021-10-181-1/+1
| | | | | | | | | | Use the proper helpers to read the block device size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* dm clone: make array 'descs' staticColin Ian King2021-10-121-1/+1
| | | | | | | | | | | | | | | | | | | 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 <colin.king@canonical.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: update target status functions to support IMA measurementTushar Sugandhi2021-08-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm-clone: use blkdev_issue_flush in commit_metadataChristoph Hellwig2021-01-271-13/+1
| | | | | | | | | | Use blkdev_issue_flush instead of open coding it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* writeback: remove bdi->congested_fnChristoph Hellwig2020-07-091-15/+0
| | | | | | | | | | | | | 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 <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Acked-by: David Sterba <dsterba@suse.com> [axboe: fixup unused variables in bcache/request.c] Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: rename generic_make_request to submit_bio_noacctChristoph Hellwig2020-07-011-5/+5
| | | | | | | | | 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 <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* dm clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions()Nikos Tsironis2020-03-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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 <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: Add missing casts to prevent overflows and data corruptionNikos Tsironis2020-03-271-3/+6
| | | | | | | | | | | | | | | 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 <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: Add overflow check for number of regionsNikos Tsironis2020-03-271-1/+11
| | | | | | | | | | | | | | | | | | 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 <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: Fix handling of partial region discardsNikos Tsironis2020-03-271-14/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: Flush destination device before committing metadataNikos Tsironis2019-12-051-6/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dm-clone maintains an on-disk bitmap which records which regions are valid in the destination device, i.e., which regions have already been hydrated, or have been written to directly, via user I/O. Setting a bit in the on-disk bitmap meas the corresponding region is valid in the destination device and we redirect all I/O regarding it to the destination device. Suppose the destination device has a volatile write-back cache and the following sequence of events occur: 1. A region gets hydrated, either through the background hydration or because it was written to directly, via user I/O. 2. The commit timeout expires and we commit the metadata, marking that region as valid in the destination device. 3. The system crashes and the destination device's cache has not been flushed, meaning the region's data are lost. The next time we read that region we read it from the destination device, since the metadata have been successfully committed, but the data are lost due to the crash, so we read garbage instead of the old data. This has several implications: 1. In case of background hydration or of writes with size smaller than the region size (which means we first copy the whole region and then issue the smaller write), we corrupt data that the user never touched. 2. In case of writes with size equal to the device's logical block size, we fail to provide atomic sector writes. When the system recovers the user will read garbage from the sector instead of the old data or the new data. 3. In case of writes without the FUA flag set, after the system recovers, the written sectors will contain garbage instead of a random mix of sectors containing either old data or new data, thus we fail again to provide atomic sector writes. 4. Even when the user flushes the dm-clone device, because we first commit the metadata and then pass down the flush, the same risk for corruption exists (if the system crashes after the metadata have been committed but before the flush is passed down). The only case which is unaffected is that of writes with size equal to the region size and with the FUA flag set. But, because FUA writes trigger metadata commits, this case can trigger the corruption indirectly. To solve this and avoid the potential data corruption we flush the destination device **before** committing the metadata. This ensures that any freshly hydrated regions, for which we commit the metadata, are properly written to non-volatile storage and won't be lost in case of a crash. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone metadata: Use a two phase commitNikos Tsironis2019-12-051-1/+6
| | | | | | | | | | | | | | | | | | | | | | Split the metadata commit in two parts: 1. dm_clone_metadata_pre_commit(): Prepare the current transaction for committing. After this is called, all subsequent metadata updates, done through either dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), will be part of the next transaction. 2. dm_clone_metadata_commit(): Actually commit the current transaction to disk and start a new transaction. This is required by the following commit. It allows dm-clone to flush the destination device after step (1) to ensure that all freshly hydrated regions, for which we are updating the metadata, are properly written to non-volatile storage and won't be lost in case of a crash. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: add bucket_lock_irq/bucket_unlock_irq helpersNikos Tsironis2019-11-051-15/+19
| | | | | | | | Introduce bucket_lock_irq() and bucket_unlock_irq() helpers and use them in places where it is known that interrupts are enabled. Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: replace spin_lock_irqsave with spin_lock_irqMikulas Patocka2019-11-051-16/+12
| | | | | | | | | | | | | If we are in a place where it is known that interrupts are enabled, functions spin_lock_irq/spin_unlock_irq should be used instead of spin_lock_irqsave/spin_unlock_irqrestore. spin_lock_irq and spin_unlock_irq are faster because they don't need to push and pop the flags register. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm clone: Make __hash_find staticYueHaibing2019-10-081-2/+2
| | | | | | | | | drivers/md/dm-clone-target.c:594:34: warning: symbol '__hash_find' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: add clone targetNikos Tsironis2019-09-121-0/+2191
Add the dm-clone target, which allows cloning of arbitrary block devices. dm-clone produces a one-to-one copy of an existing, read-only source device into a writable destination device: It presents a virtual block device which makes all data appear immediately, and redirects reads and writes accordingly. The main use case of dm-clone is to clone a potentially remote, high-latency, read-only, archival-type block device into a writable, fast, primary-type device for fast, low-latency I/O. The cloned device is visible/mountable immediately and the copy of the source device to the destination device happens in the background, in parallel with user I/O. When the cloning completes, the dm-clone table can be removed altogether and be replaced, e.g., by a linear table, mapping directly to the destination device. For further information and examples of how to use dm-clone, please read Documentation/admin-guide/device-mapper/dm-clone.rst Suggested-by: Vangelis Koukis <vkoukis@arrikto.com> Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>