kernel/linux.git/drivers/md/dm-switch.c, branch v6.19.11

dm: use vmalloc_array() to simplify code

2025-08-19T09:12:50+00:00

Remove array_size() calls and replace vmalloc() with vmalloc_array() to simplify the code. Signed-off-by: Qianfeng Rong Signed-off-by: Mikulas Patocka

dm: Allow .prepare_ioctl to handle ioctls directly

2025-05-04T09:35:05+00:00

This adds a 'bool *forward' parameter to .prepare_ioctl, which allows device mapper targets to accept ioctls to themselves instead of the underlying device. If the target already fully handled the ioctl, it sets *forward to false and device mapper won't forward it to the underlying device any more. In order for targets to actually know what the ioctl is about and how to handle it, pass also cmd and arg. As long as targets restrict themselves to interpreting ioctls of type DM_IOCTL, this is a backwards compatible change because previously, any such ioctl would have been passed down through all device mapper layers until it reached a device that can't understand the ioctl and would return an error. Signed-off-by: Kevin Wolf Reviewed-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka

dm: add helper macro for simple DM target module init and exit

2023-04-11T16:09:08+00:00

Eliminate duplicate boilerplate code for simple modules that contain a single DM target driver without any additional setup code. Add a new module_dm() macro, which replaces the module_init() and module_exit() with template functions that call dm_register_target() and dm_unregister_target() respectively. Signed-off-by: Yangtao Li Signed-off-by: Mike Snitzer

dm: push error reporting down to dm_register_target()

2023-04-11T16:01:01+00:00

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 Signed-off-by: Mike Snitzer

dm: change "unsigned" to "unsigned int"

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: add missing SPDX-License-Indentifiers

2023-02-14T19:23:06+00:00

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has deprecated its use. Suggested-by: John Wiele Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: use bdev_nr_sectors and bdev_nr_bytes instead of open coding them

2021-10-18T20:43:22+00:00

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: 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

dm: add support for REQ_NOWAIT to various targets

2020-12-04T23:04:35+00:00

commit 021a24460dc2 ("block: add QUEUE_FLAG_NOWAIT") added a new queue flag QUEUE_FLAG_NOWAIT to advertise if the bdev supports handling of REQ_NOWAIT or not. DM core supports stacking QUEUE_FLAG_NOWAIT since commit 6abc49468eea ("dm: add support for REQ_NOWAIT and enable it for linear target"), in which only dm-linear enabled it. Update others DM targets, which just do simple remapping, to enable support for REQ_NOWAIT. Signed-off-by: Jeffle Xu Signed-off-by: Mike Snitzer

dm: replace zero-length array with flexible-array

2020-05-20T21:09:44+00:00

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