kernel.git/drivers/md/dm-raid1.c, branch linux-5.14.y

dm kcopyd: avoid useless atomic operations

2021-06-04T16:07:24Z

The functions set_bit and clear_bit are atomic. We don't need atomicity when making flags for dm-kcopyd. So, change them to direct manipulation of the flags. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

block: store a block_device pointer in struct bio

2021-01-25T01:17:20Z

Replace the gendisk pointer in struct bio with a pointer to the newly improved struct block device. From that the gendisk can be trivially accessed with an extra indirection, but it also allows to directly look up all information related to partition remapping. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo 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: 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