linux-toradex.git/drivers/md/dm-raid1.c, branch v6.0-rc4

dm/core: Reduce the size of struct dm_io_request

2022-07-14T18:14:31+00:00

Combine the bi_op and bi_op_flags into the bi_opf member. Use the new
blk_opf_t type to improve static type checking. This patch does not
change any functionality.

Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: Mikulas Patocka 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20220714180729.1065367-22-bvanassche@acm.org
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 kcopyd: avoid useless atomic operations

2021-06-04T16:07:24+00:00

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

2021-01-25T01:17:20+00:00

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

2020-07-01T13:27:24+00:00

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

2020-05-20T21:09:44+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

dm raid1: use struct_size() with kzalloc()

2019-08-26T15:05:32+00:00

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

2018-12-18T14:02:26+00:00

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()

2018-07-31T21:33:21+00:00

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

2018-05-04T14:35:20+00:00

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