kernel/linux.git/drivers/ide/ide-atapi.c, branch v4.14.286

scsi: ide: Do not set the RQF_PREEMPT flag for sense requests

2021-01-12T19:09:05+00:00

[ Upstream commit 96d86e6a80a3ab9aff81d12f9f1f2a0da2917d38 ] RQF_PREEMPT is used for two different purposes in the legacy IDE code: 1. To mark power management requests. 2. To mark requests that should preempt another request. An (old) explanation of that feature is as follows: "The IDE driver in the Linux kernel normally uses a series of busywait delays during its initialization. When the driver executes these busywaits, the kernel does nothing for the duration of the wait. The time spent in these waits could be used for other initialization activities, if they could be run concurrently with these waits. More specifically, busywait-style delays such as udelay() in module init functions inhibit kernel preemption because the Big Kernel Lock is held, while yielding APIs such as schedule_timeout() allow preemption. This is true because the kernel handles the BKL specially and releases and reacquires it across reschedules allowed by the current thread. This IDE-preempt specification requires that the driver eliminate these busywaits and replace them with a mechanism that allows other work to proceed while the IDE driver is initializing." Since I haven't found an implementation of (2), do not set the PREEMPT flag for sense requests. This patch causes sense requests to be postponed while a drive is suspended instead of being submitted to ide_queue_rq(). If it would ever be necessary to restore the IDE PREEMPT functionality, that can be done by introducing a new flag in struct ide_request. Link: https://lore.kernel.org/r/20201209052951.16136-4-bvanassche@acm.org Cc: David S. Miller Cc: Alan Stern Cc: Can Guo Cc: Stanley Chu Cc: Ming Lei Cc: Rafael J. Wysocki Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Jens Axboe Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

ide: ide-atapi: fix compile error with defining macro DEBUG

2017-12-17T14:08:00+00:00

[ Upstream commit 8dc7a31fbce5e2dbbacd83d910da37105181b054 ] Compile ide-atapi failed with defining macro "DEBUG" ... |drivers/ide/ide-atapi.c:285:52: error: 'struct request' has no member named 'cmd'; did you mean 'csd'? | debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]); ... Since we split the scsi_request out of struct request, it missed do the same thing on debug_log Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request") Signed-off-by: Hongxu Jia Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

block: Change argument type of scsi_req_init()

2017-06-21T01:27:14+00:00

Since scsi_req_init() works on a struct scsi_request, change the argument type into struct scsi_request *. Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: Make most scsi_req_init() calls implicit

2017-06-21T01:27:14+00:00

Instead of explicitly calling scsi_req_init() after blk_get_request(), call that function from inside blk_get_request(). Add an .initialize_rq_fn() callback function to the block drivers that need it. Merge the IDE .init_rq_fn() function into .initialize_rq_fn() because it is too small to keep it as a separate function. Keep the scsi_req_init() call in ide_prep_sense() because it follows a blk_rq_init() call. References: commit 82ed4db499b8 ("block: split scsi_request out of struct request") Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Omar Sandoval Cc: Nicholas Bellinger Signed-off-by: Jens Axboe

block: introduce new block status code type

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

Currently we use nornal Linux errno values in the block layer, and while we accept any error a few have overloaded magic meanings. This patch instead introduces a new blk_status_t value that holds block layer specific status codes and explicitly explains their meaning. Helpers to convert from and to the previous special meanings are provided for now, but I suspect we want to get rid of them in the long run - those drivers that have a errno input (e.g. networking) usually get errnos that don't know about the special block layer overloads, and similarly returning them to userspace will usually return somethings that strictly speaking isn't correct for file system operations, but that's left as an exercise for later. For now the set of errors is a very limited set that closely corresponds to the previous overloaded errno values, but there is some low hanging fruite to improve it. blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse typechecking, so that we can easily catch places passing the wrong values. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

scsi: introduce a result field in struct scsi_request

2017-04-20T18:16:10+00:00

This passes on the scsi_cmnd result field to users of passthrough requests. Currently we abuse req->errors for this purpose, but that field will go away in its current form. Note that the old IDE code abuses the errors field in very creative ways and stores all kinds of different values in it. I didn't dare to touch this magic, so the abuses are brought forward 1:1. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe

block: remove the blk_execute_rq return value

2017-04-20T18:16:10+00:00

The function only returns -EIO if rq->errors is non-zero, which is not very useful and lets a large number of callers ignore the return value. Just let the callers figure out their error themselves. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe

block: fold cmd_type into the REQ_OP_ space

2017-01-31T21:00:44+00:00

Instead of keeping two levels of indirection for requests types, fold it all into the operations. The little caveat here is that previously cmd_type only applied to struct request, while the request and bio op fields were set to plain REQ_OP_READ/WRITE even for passthrough operations. Instead this patch adds new REQ_OP_* for SCSI passthrough and driver private requests, althought it has to add two for each so that we can communicate the data in/out nature of the request. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

ide: don't abuse cmd_type

2017-01-31T21:00:39+00:00

Currently the legacy ide driver defines several request types of it's own, which is in the way of removing that field entirely. Instead add a type field to struct ide_request and use that to distinguish the different types of IDE-internal requests. It's a bit of a mess, but so is the surrounding code.. Signed-off-by: Christoph Hellwig Acked-by: David S. Miller Signed-off-by: Jens Axboe

block: split scsi_request out of struct request

2017-01-27T22:08:35+00:00

And require all drivers that want to support BLOCK_PC to allocate it as the first thing of their private data. To support this the legacy IDE and BSG code is switched to set cmd_size on their queues to let the block layer allocate the additional space. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe