kernel/linux.git/drivers/md/dm-zero.c, branch v6.6.132

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 zero: add discard support

2023-04-04T17:30:17+00:00

Add zero_io_hints() and set discard limits so that the zero target advertises support for discards. The zero target will ignore discards. This is useful when the user combines dm-zero with other discard-supporting targets in the same table; without dm-zero support, discards would be disabled for the whole combined device. Signed-off-by: Mikulas Patocka Tested-by: Milan Broz 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: 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: don't return errnos from ->map

2017-06-09T15:27:32+00:00

Instead use the special DM_MAPIO_KILL return value to return -EIO just like we do for the request based path. Note that dm-log-writes returned -ENOMEM in a few places, which now becomes -EIO instead. No consumer treats -ENOMEM special so this shouldn't be an issue (and it should use a mempool to start with to make guaranteed progress). Signed-off-by: Christoph Hellwig Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

block: rename bio bi_rw to bi_opf

2016-08-07T20:41:02+00:00

Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe

block: get rid of bio_rw and READA

2016-07-20T23:37:01+00:00

These two are confusing leftover of the old world order, combining values of the REQ_OP_ and REQ_ namespaces. For callers that don't special case we mostly just replace bi_rw with bio_data_dir or op_is_write, except for the few cases where a switch over the REQ_OP_ values makes more sense. Any check for READA is replaced with an explicit check for REQ_RAHEAD. Also remove the READA alias for REQ_RAHEAD. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Mike Christie Signed-off-by: Jens Axboe

block: add a bi_error field to struct bio

2015-07-29T14:55:15+00:00

Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe

dm crypt, dm zero: update author name following legal name change

2014-07-10T20:44:14+00:00

Signed-off-by: Jana Saout Signed-off-by: Mike Snitzer