kernel.git/drivers/md/dm-raid1.c, branch linux-5.10.y

dm-mirror: fix a tiny race condition

2025-06-27T10:04:14Z

commit 829451beaed6165eb11d7a9fb4e28eb17f489980 upstream. There's a tiny race condition in dm-mirror. The functions queue_bio and write_callback grab a spinlock, add a bio to the list, drop the spinlock and wake up the mirrord thread that processes bios in the list. It may be possible that the mirrord thread processes the bio just after spin_unlock_irqrestore is called, before wakeup_mirrord. This spurious wake-up is normally harmless, however if the device mapper device is unloaded just after the bio was processed, it may be possible that wakeup_mirrord(ms) uses invalid "ms" pointer. Fix this bug by moving wakeup_mirrord inside the spinlock. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

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: replace zero-length array with flexible-array

2020-05-20T21:09:44Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Mike Snitzer

dm raid1: use struct_size() with kzalloc()

2019-08-26T15:05:32Z

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct mirror_set { ... struct mirror mirror[0]; }; size = sizeof(struct mirror_set) + count * sizeof(struct mirror); instance = kzalloc(size, GFP_KERNEL) Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, mirror, count), GFP_KERNEL) Notice that, in this case, variable len is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Mike Snitzer

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

2018-12-18T14:02:26Z

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 kcopyd: return void from dm_kcopyd_copy()

2018-07-31T21:33:21Z

dm_kcopyd_copy() only ever returns 0 so there is no need for callers to account for possible failure. Same goes for dm_kcopyd_zero(). Signed-off-by: Mike Snitzer

dm mirror: remove VLA usage

2018-05-04T14:35:20Z

On the quest to remove all VLAs from the kernel[1], this avoids VLAs in dm-raid1.c by just using the maximum size for the stack arrays. The nr_mirrors value was already capped at 9, so this makes it a trivial adjustment to the array sizes. [1] https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Kees Cook Acked-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

md: Convert timers to use timer_setup()

2017-11-15T03:11:57Z

In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Kent Overstreet Cc: Shaohua Li Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: linux-bcache@vger.kernel.org Cc: linux-raid@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Michael Lyle Reviewed-by: Mike Snitzer Signed-off-by: Jens Axboe

block: replace bi_bdev with a gendisk pointer and partitions index

2017-08-23T18:49:55Z

This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

Merge branch 'for-4.13/block' of git://git.kernel.dk/linux-block

2017-07-03T17:34:51Z

Pull core block/IO updates from Jens Axboe: "This is the main pull request for the block layer for 4.13. Not a huge round in terms of features, but there's a lot of churn related to some core cleanups. Note this depends on the UUID tree pull request, that Christoph already sent out. This pull request contains: - A series from Christoph, unifying the error/stats codes in the block layer. We now use blk_status_t everywhere, instead of using different schemes for different places. - Also from Christoph, some cleanups around request allocation and IO scheduler interactions in blk-mq. - And yet another series from Christoph, cleaning up how we handle and do bounce buffering in the block layer. - A blk-mq debugfs series from Bart, further improving on the support we have for exporting internal information to aid debugging IO hangs or stalls. - Also from Bart, a series that cleans up the request initialization differences across types of devices. - A series from Goldwyn Rodrigues, allowing the block layer to return failure if we will block and the user asked for non-blocking. - Patch from Hannes for supporting setting loop devices block size to that of the underlying device. - Two series of patches from Javier, fixing various issues with lightnvm, particular around pblk. - A series from me, adding support for write hints. This comes with NVMe support as well, so applications can help guide data placement on flash to improve performance, latencies, and write amplification. - A series from Ming, improving and hardening blk-mq support for stopping/starting and quiescing hardware queues. - Two pull requests for NVMe updates. Nothing major on the feature side, but lots of cleanups and bug fixes. From the usual crew. - A series from Neil Brown, greatly improving the bio rescue set support. Most notably, this kills the bio rescue work queues, if we don't really need them. - Lots of other little bug fixes that are all over the place" * 'for-4.13/block' of git://git.kernel.dk/linux-block: (217 commits) lightnvm: pblk: set line bitmap check under debug lightnvm: pblk: verify that cache read is still valid lightnvm: pblk: add initialization check lightnvm: pblk: remove target using async. I/Os lightnvm: pblk: use vmalloc for GC data buffer lightnvm: pblk: use right metadata buffer for recovery lightnvm: pblk: schedule if data is not ready lightnvm: pblk: remove unused return variable lightnvm: pblk: fix double-free on pblk init lightnvm: pblk: fix bad le64 assignations nvme: Makefile: remove dead build rule blk-mq: map all HWQ also in hyperthreaded system nvmet-rdma: register ib_client to not deadlock in device removal nvme_fc: fix error recovery on link down. nvmet_fc: fix crashes on bad opcodes nvme_fc: Fix crash when nvme controller connection fails. nvme_fc: replace ioabort msleep loop with completion nvme_fc: fix double calls to nvme_cleanup_cmd() nvme-fabrics: verify that a controller returns the correct NQN nvme: simplify nvme_dev_attrs_are_visible ...