kernel/linux.git/drivers/cdrom, branch master

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

2026-04-27T21:52:51+00:00

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

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

cdrom: Call cdrom_mrw_exit from cdrom_release function

2025-07-23T01:10:17+00:00

Remove the cdrom_mrw_exit call from unregister_cdrom, as it invokes block commands that can fail due to a NULL pointer dereference from the call happening too late, during the unloading of the driver (e.g. unplugging of USB optical drives). Instead perform the call inside cdrom_release, thus also removing the need for the exit function pointer inside the cdrom_device_info struct. Reported-by: Sergey Senozhatsky Closes: https://lore.kernel.org/linux-block/uxgzea5ibqxygv3x7i4ojbpvcpv2wziorvb3ns5cdtyvobyn7h@y4g4l5ezv2ec Suggested-by: Jens Axboe Link: https://lore.kernel.org/linux-block/6686fe78-a050-4a1d-aa27-b7bf7ca6e912@kernel.dk Tested-by: Phillip Potter Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20250722231900.1164-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

cdrom: Remove unnecessary NULL check before unregister_sysctl_table()

2025-05-15T22:25:20+00:00

unregister_sysctl_table() checks for NULL pointers internally. Remove unneeded NULL check here. Signed-off-by: Chen Ni Link: https://lore.kernel.org/lkml/20250514032139.2317578-1-nichen@iscas.ac.cn Reviewed-by: Phillip Potter Link: https://lore.kernel.org/lkml/aCURuvkmz-fw3Nnp@equinox Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20250514223354.1429-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

treewide: const qualify ctl_tables where applicable

2025-01-28T12:48:37+00:00

Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu Acked-by: Steven Rostedt (Google) # for kernel/trace/ Reviewed-by: Martin K. Petersen # SCSI Reviewed-by: Darrick J. Wong # xfs Acked-by: Jani Nikula Acked-by: Corey Minyard Acked-by: Wei Liu Acked-by: Thomas Gleixner Reviewed-by: Bill O'Donnell Acked-by: Baoquan He Acked-by: Ashutosh Dixit Acked-by: Anna Schumaker Signed-off-by: Joel Granados

Merge tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux

2025-01-21T03:38:46+00:00

Pull block updates from Jens Axboe: - NVMe pull requests via Keith: - Target support for PCI-Endpoint transport (Damien) - TCP IO queue spreading fixes (Sagi, Chaitanya) - Target handling for "limited retry" flags (Guixen) - Poll type fix (Yongsoo) - Xarray storage error handling (Keisuke) - Host memory buffer free size fix on error (Francis) - MD pull requests via Song: - Reintroduce md-linear (Yu Kuai) - md-bitmap refactor and fix (Yu Kuai) - Replace kmap_atomic with kmap_local_page (David Reaver) - Quite a few queue freeze and debugfs deadlock fixes Ming introduced lockdep support for this in the 6.13 kernel, and it has (unsurprisingly) uncovered quite a few issues - Use const attributes for IO schedulers - Remove bio ioprio wrappers - Fixes for stacked device atomic write support - Refactor queue affinity helpers, in preparation for better supporting isolated CPUs - Cleanups of loop O_DIRECT handling - Cleanup of BLK_MQ_F_* flags - Add rotational support for null_blk - Various fixes and cleanups * tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux: (106 commits) block: Don't trim an atomic write block: Add common atomic writes enable flag md/md-linear: Fix a NULL vs IS_ERR() bug in linear_add() block: limit disk max sectors to (LLONG_MAX >> 9) block: Change blk_stack_atomic_writes_limits() unit_min check block: Ensure start sector is aligned for stacking atomic writes blk-mq: Move more error handling into blk_mq_submit_bio() block: Reorder the request allocation code in blk_mq_submit_bio() nvme: fix bogus kzalloc() return check in nvme_init_effects_log() md/md-bitmap: move bitmap_{start, end}write to md upper layer md/raid5: implement pers->bitmap_sector() md: add a new callback pers->bitmap_sector() md/md-bitmap: remove the last parameter for bimtap_ops->endwrite() md/md-bitmap: factor behind write counters out from bitmap_{start/end}write() md: Replace deprecated kmap_atomic() with kmap_local_page() md: reintroduce md-linear partitions: ldm: remove the initial kernel-doc notation blk-cgroup: rwstat: fix kernel-doc warnings in header file blk-cgroup: fix kernel-doc warnings in header file nbd: fix partial sending ...

cdrom: Fix typo, 'devicen' to 'device'

2024-12-30T19:56:06+00:00

Fix typo in cd_dbg line to add trailing newline character. Signed-off-by: Steven Davis Link: https://lore.kernel.org/lkml/20241229165744.21725-1-goldside000@outlook.com Reviewed-by: Phillip Potter Link: https://lore.kernel.org/lkml/Z3GV2W_MUOw5BrtR@equinox Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20241230193431.441120-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

block: remove BLK_MQ_F_SHOULD_MERGE

2024-12-23T15:17:23+00:00

BLK_MQ_F_SHOULD_MERGE is set for all tag_sets except those that purely process passthrough commands (bsg-lib, ufs tmf, various nvme admin queues) and thus don't even check the flag. Remove it to simplify the driver interface. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20241219060214.1928848-1-hch@lst.de Signed-off-by: Jens Axboe

Get rid of 'remove_new' relic from platform driver struct

2024-12-01T23:12:43+00:00

The continual trickle of small conversion patches is grating on me, and is really not helping. Just get rid of the 'remove_new' member function, which is just an alias for the plain 'remove', and had a comment to that effect: /* * .remove_new() is a relic from a prototype conversion of .remove(). * New drivers are supposed to implement .remove(). Once all drivers are * converted to not use .remove_new any more, it will be dropped. */ This was just a tree-wide 'sed' script that replaced '.remove_new' with '.remove', with some care taken to turn a subsequent tab into two tabs to make things line up. I did do some minimal manual whitespace adjustment for places that used spaces to line things up. Then I just removed the old (sic) .remove_new member function, and this is the end result. No more unnecessary conversion noise. Signed-off-by: Linus Torvalds