kernel/drivers/md/persistent-data/dm-btree-internal.h, branch linux-6.9.y

dm: favour packed versus "attribute__ ((packed))"

2023-02-14T19:23:07Z

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

dm: favour aligned(N) versus "attribute__ (aligned(N))"

2023-02-14T19:23:07Z

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

dm: add missing empty lines

2023-02-14T19:23:06Z

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

dm: add missing SPDX-License-Indentifiers

2023-02-14T19:23:06Z

'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 space maps: improve performance with inc/dec on ranges of blocks

2021-06-04T16:07:22Z

When we break sharing on btree nodes we typically need to increment the reference counts to every value held in the node. This can cause a lot of repeated calls to the space maps. Fix this by changing the interface to the space map inc/dec methods to take ranges of adjacent blocks to be operated on. For installations that are using a lot of snapshots this will reduce cpu overhead of fundamental operations such as provisioning a new block, or deleting a snapshot, by as much as 10 times. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm persistent data: packed struct should have an aligned() attribute too

2021-04-19T16:48:12Z

Otherwise most non-x86 architectures (e.g. riscv, arm) will resort to byte-by-byte access. Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm persistent data: remove unused return from exit_shadow_spine()

2021-03-26T18:53:42Z

Fix the following coccicheck warnings: ./drivers/md/persistent-data/dm-btree-spine.c:188:5-6: Unneeded variable: "r". Return "0" on line 194. Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong Signed-off-by: Mike Snitzer

dm persistent data: fix return type of shadow_root()

2021-02-03T15:10:05Z

shadow_root() truncates 64-bit dm_block_t into 32-bit int. This is not an issue in practice, since dm metadata as of v5.11 can only hold at most 4161600 blocks (255 index entries * ~16k metadata blocks). Nevertheless, this can confuse users debugging some specific data corruption scenarios. Also, DM_SM_METADATA_MAX_BLOCKS may be bumped in the future, or persistent-data may find its use in other places. Therefore, switch the return type of shadow_root from int to dm_block_t. Signed-off-by: Jinoh Kang Signed-off-by: Mike Snitzer

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 persistent data: switch exit_ro_spine to return void

2020-05-15T14:29:35Z

In commit 4c7da06f5a78 ("dm persistent data: eliminate unnecessary return values"), r value in exit_ro_spine will not change, so exit_ro_spine doesn't need a return value. Signed-off-by: Zhiqiang Liu Signed-off-by: Mike Snitzer

kernel/drivers/md/persistent-data/dm-btree-internal.h, branch linux-6.9.y

dm: favour __packed versus "__attribute__ ((packed))"

dm: favour __aligned(N) versus "__attribute__ (aligned(N))"

dm: add missing empty lines

dm: add missing SPDX-License-Indentifiers

dm space maps: improve performance with inc/dec on ranges of blocks

dm persistent data: packed struct should have an aligned() attribute too

dm persistent data: remove unused return from exit_shadow_spine()

dm persistent data: fix return type of shadow_root()

dm: replace zero-length array with flexible-array

dm persistent data: switch exit_ro_spine to return void

dm: favour packed versus "attribute__ ((packed))"

dm: favour aligned(N) versus "attribute__ (aligned(N))"