kernel/linux.git/drivers/block/floppy.c, branch v5.9.12

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

floppy: use block_size

2020-07-01T14:08:08+00:00

Use the block_size helper instead of open coding it. Also remove the check for a 0 block size, as that can't happen. Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block/floppy: fix contended case in floppy_queue_rq()

2020-05-26T21:23:54+00:00

Since the switch of floppy driver to blk-mq, the contended (fdc_busy) case in floppy_queue_rq() is not handled correctly. In case we reach floppy_queue_rq() with fdc_busy set (i.e. with the floppy locked due to another request still being in-flight), we put the request on the list of requests and return BLK_STS_OK to the block core, without actually scheduling delayed work / doing further processing of the request. This means that processing of this request is postponed until another request comes and passess uncontended. Which in some cases might actually never happen and we keep waiting indefinitely. The simple testcase is for i in `seq 1 2000`; do echo -en $i '\r'; blkid --info /dev/fd0 2> /dev/null; done run in quemu. That reliably causes blkid eventually indefinitely hanging in __floppy_read_block_0() waiting for completion, as the BIO callback never happens, and no further IO is ever submitted on the (non-existent) floppy device. This was observed reliably on qemu-emulated device. Fix that by not queuing the request in the contended case, and return BLK_STS_RESOURCE instead, so that blk core handles the request rescheduling and let it pass properly non-contended later. Fixes: a9f38e1dec107a ("floppy: convert to blk-mq") Cc: stable@vger.kernel.org Tested-by: Libor Pechacek Signed-off-by: Jiri Kosina Signed-off-by: Jens Axboe

floppy: suppress UBSAN warning in setup_rw_floppy()

2020-05-12T16:34:57+00:00

UBSAN: array-index-out-of-bounds in drivers/block/floppy.c:1521:45 index 16 is out of range for type 'unsigned char [16]' Call Trace: ... setup_rw_floppy+0x5c3/0x7f0 floppy_ready+0x2be/0x13b0 process_one_work+0x2c1/0x5d0 worker_thread+0x56/0x5e0 kthread+0x122/0x170 ret_from_fork+0x35/0x40 From include/uapi/linux/fd.h: struct floppy_raw_cmd { ... unsigned char cmd_count; unsigned char cmd[16]; unsigned char reply_count; unsigned char reply[16]; ... } This out-of-bounds access is intentional. The command in struct floppy_raw_cmd may take up the space initially intended for the reply and the reply count. It is needed for long 82078 commands such as RESTORE, which takes 17 command bytes. Initial cmd size is not enough and since struct setup_rw_floppy is a part of uapi we check that cmd_count is in [0:16+1+16] in raw_cmd_copyin(). The patch adds union with original cmd,reply_count,reply fields and fullcmd field of equivalent size. The cmd accesses are turned to fullcmd where appropriate to suppress UBSAN warning. Link: https://lore.kernel.org/r/20200501134416.72248-5-efremov@linux.com Reviewed-by: Christoph Hellwig Signed-off-by: Denis Efremov

floppy: add defines for sizes of cmd & reply buffers of floppy_raw_cmd

2020-05-12T16:34:56+00:00

Use FD_RAW_CMD_SIZE, FD_RAW_REPLY_SIZE defines instead of magic numbers for cmd & reply buffers of struct floppy_raw_cmd. Remove local to floppy.c MAX_REPLIES define, as it is now FD_RAW_REPLY_SIZE. FD_RAW_CMD_FULLSIZE added as we allow command to also fill reply_count and reply fields. Link: https://lore.kernel.org/r/20200501134416.72248-4-efremov@linux.com Reviewed-by: Christoph Hellwig Signed-off-by: Denis Efremov

floppy: add FD_AUTODETECT_SIZE define for struct floppy_drive_params

2020-05-12T16:34:56+00:00

Use FD_AUTODETECT_SIZE for autodetect buffer size in struct floppy_drive_params instead of a magic number. Link: https://lore.kernel.org/r/20200501134416.72248-3-efremov@linux.com Reviewed-by: Christoph Hellwig Signed-off-by: Denis Efremov

floppy: use print_hex_dump() in setup_DMA()

2020-05-12T16:34:56+00:00

Remove pr_cont() and use print_hex_dump() in setup_DMA() to print the contents of the cmd buffer. Link: https://lore.kernel.org/r/20200501134416.72248-2-efremov@linux.com Suggested-by: Joe Perches Reviewed-by: Christoph Hellwig Signed-off-by: Denis Efremov

floppy: cleanup: make set_fdc() always set current_drive and current_fd

2020-05-12T16:34:56+00:00

When called with a negative drive value, set_fdc() would stick to the current fdc (which was assumed to reflect the current_drive's FDC). We do not need this anymore as the last call place with a negative value was just addressed. Let's make this function always set both current_fdc and current_drive so that there's no more ambiguity. A few comments stating this were added to a few non-obvious places. Link: https://lore.kernel.org/r/20200410101904.14652-3-w@1wt.eu Signed-off-by: Willy Tarreau Signed-off-by: Denis Efremov

floppy: cleanup: get rid of current_reqD in favor of current_drive

2020-05-12T16:34:56+00:00

This macro equals -1 and is used as an alternative for current_drive when calling reschedule_timeout(), which in turn needs to remap it. This only adds obfuscation, let's simply use current_drive. Link: https://lore.kernel.org/r/20200410101904.14652-2-w@1wt.eu Signed-off-by: Willy Tarreau Signed-off-by: Denis Efremov

floppy: make sure to reset all FDCs upon resume()

2020-05-12T16:34:56+00:00

In floppy_resume() we don't properly reinitialize all FDCs, instead we reinitialize the current FDC once per available FDC because value -1 is passed to user_reset_fdc(). Let's simply save the current drive and properly reinitialize each FDC. Link: https://lore.kernel.org/r/20200410101904.14652-1-w@1wt.eu Signed-off-by: Willy Tarreau Signed-off-by: Denis Efremov