linux-stable.git/drivers/ide/ide-atapi.c, branch linux-5.4.y

treewide: Remove uninitialized_var() usage

2023-06-09T08:29:01+00:00

commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky  # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe  # IB
Acked-by: Kalle Valo  # wireless drivers
Reviewed-by: Chao Yu  # erofs
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

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

2021-01-12T19:16:09+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

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

ide: ensure atapi sense request aren't preempted

2019-01-31T15:25:09+00:00

There's an issue with how sense requests are handled in IDE. If ide-cd
encounters an error, it queues a sense request. With how IDE request
handling is done, this is the next request we need to handle. But it's
impossible to guarantee this, as another request could come in between
the sense being queued, and ->queue_rq() being run and handling it. If
that request ALSO fails, then we attempt to doubly queue the single
sense request we have.

Since we only support one active request at the time, defer request
processing when a sense request is queued.

Fixes: 600335205b8d "ide: convert to blk-mq"
Reported-by: He Zhe 
Tested-by: He Zhe 
Signed-off-by: Jens Axboe

ide: don't use req->special

2018-11-10T15:03:52+00:00

Just replace it with a field of the same name in struct ide_req.

Reviewed-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

ide: convert to blk-mq

2018-11-07T20:42:31+00:00

ide-disk and ide-cd tested as working just fine, ide-tape and
ide-floppy haven't. But the latter don't require changes, so they
should work without issue.

Add helper function to insert a request from a work queue, since we
cannot invoke the blk-mq request insertion from IRQ context.

Cc: David Miller 
Reviewed-by: Hannes Reinecke 
Tested-by: Ming Lei 
Reviewed-by: Omar Sandoval 
Signed-off-by: Jens Axboe

block: sanitize blk_get_request calling conventions

2018-05-14T14:55:12+00:00

Switch everyone to blk_get_request_flags, and then rename
blk_get_request_flags to blk_get_request.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe

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

2017-11-11T02:56:25+00:00

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

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