kernel/linux.git/drivers/scsi/sr.c, branch v7.0.10

cdrom, scsi: sr: propagate read-only status to block layer via set_disk_ro()

2026-05-23T11:09:28+00:00

[ Upstream commit 0898a817621a2f0cddca8122d9b974003fe5036d ] The cdrom core never calls set_disk_ro() for a registered device, so BLKROGET on a CD-ROM device always returns 0 (writable), even when the drive has no write capabilities and writes will inevitably fail. This causes problems for userspace that relies on BLKROGET to determine whether a block device is read-only. For example, systemd's loop device setup uses BLKROGET to decide whether to create a loop device with LO_FLAGS_READ_ONLY. Without the read-only flag, writes pass through the loop device to the CD-ROM and fail with I/O errors. systemd-fsck similarly checks BLKROGET to decide whether to run fsck in no-repair mode (-n). The write-capability bits in cdi->mask come from two different sources: CDC_DVD_RAM and CDC_CD_RW are populated by the driver from the MODE SENSE capabilities page (page 0x2A) before register_cdrom() is called, while CDC_MRW_W and CDC_RAM require the MMC GET CONFIGURATION command and were only probed by cdrom_open_write() at device open time. This meant that any attempt to compute the writable state from the full mask at probe time was incorrect, because the GET CONFIGURATION bits were still unset (and cdi->mask is initialized such that capabilities are assumed present). Fix this by factoring the GET CONFIGURATION probing out of cdrom_open_write() into a new exported helper, cdrom_probe_write_features(), and having sr call it from sr_probe() right after get_capabilities() has populated the MODE SENSE bits. register_cdrom() then calls set_disk_ro() based on the full write-capability mask (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW) so the block layer reflects the drive's actual write support. The feature queries used (CDF_MRW and CDF_RWRT via GET CONFIGURATION with RT=00) report drive-level capabilities that are persistent across media, so a single probe before register_cdrom() is sufficient and the redundant probe at open time is dropped. With set_disk_ro() now accurate, the long-vestigial cd->writeable flag in sr can go: get_capabilities() used to set cd->writeable based on the same four mask bits, but because CDC_MRW_W and CDC_RAM default to "capability present" in cdi->mask and aren't touched by MODE SENSE, the condition that gated cd->writeable was always true, making it unconditionally 1. Replace the corresponding gate in sr_init_command() with get_disk_ro(cd->disk), which turns a previously no-op check into a real one and also catches kernel-internal bio writers that bypass blkdev_write_iter()'s bdev_read_only() check. The sd driver (SCSI disks) does not have this problem because it checks the MODE SENSE Write Protect bit and calls set_disk_ro() accordingly. The sr driver cannot use the same approach because the MMC specification does not define the WP bit in the MODE SENSE device-specific parameter byte for CD-ROM devices. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Daan De Meyer Reviewed-by: Phillip Potter Reviewed-by: Martin K. Petersen Signed-off-by: Phillip Potter Link: https://patch.msgid.link/20260427210139.1400-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

scsi: sr: Convert to SCSI bus methods

2026-01-12T02:31:58+00:00

The SCSI subsystem has implemented dedicated callbacks for probe, remove and shutdown. Make use of them. This fixes a runtime warning about the driver needing to be converted to the bus probe method. Signed-off-by: Uwe Kleine-König Reviewed-by: Bart Van Assche Link: https://patch.msgid.link/ff6e8421f9efa84be3c37a11637aa435899160bf.1766133330.git.u.kleine-koenig@baylibre.com Signed-off-by: Martin K. Petersen

scsi: core: Pass a struct scsi_driver to scsi_{,un}register_driver()

2026-01-12T02:31:57+00:00

This aligns with what other subsystems do, reduces boilerplate a bit for device drivers and is less error prone. Reviewed-by: Peter Wang Signed-off-by: Uwe Kleine-König Reviewed-by: Bart Van Assche Link: https://patch.msgid.link/ac17fdea58e384cb514c639306d48ce0005820b0.1766133330.git.u.kleine-koenig@baylibre.com Signed-off-by: Martin K. Petersen

scsi: sr: Reinstate rotational media flag

2025-08-31T01:46:21+00:00

Reinstate the rotational media flag for the CD-ROM driver. The flag has been cleared since commit bd4a633b6f7c ("block: move the nonrot flag to queue_limits") and this breaks some applications. Move queue limit configuration from get_sectorsize() to sr_revalidate_disk() and set the rotational flag. Cc: Christoph Hellwig Fixes: bd4a633b6f7c ("block: move the nonrot flag to queue_limits") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250827113550.2614535-1-ming.lei@redhat.com Signed-off-by: Martin K. Petersen

block: add a queue_limits_commit_update_frozen helper

2025-01-10T14:29:23+00:00

Add a helper that freezes the queue, updates the queue limits and unfreezes the queue and convert all open coded versions of that to the new helper. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Ming Lei Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Reviewed-by: Nilay Shroff Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250110054726.1499538-3-hch@lst.de Signed-off-by: Jens Axboe

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

sr: convert to the atomic queue limits API

2024-06-14T16:19:44+00:00

Assign all queue limits through a local queue_limits variable and queue_limits_commit_update so that we can't race updating them from multiple places, and free the queue when updating them so that in-progress I/O submissions don't see half-updated limits. Also use the chance to clean up variable names to standard ones. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240531074837.1648501-13-hch@lst.de Signed-off-by: Jens Axboe

scsi: sr: Drop driver owner initialization

2024-04-06T00:58:25+00:00

Core in scsi_register_driver() already sets the .owner, so driver does not need to. Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20240328-b4-module-owner-scsi-v1-4-c86cb4f6e91c@linaro.org Signed-off-by: Martin K. Petersen