kernel/drivers/md/md-multipath.c, branch linux-6.9.y

md: Remove deprecated CONFIG_MD_MULTIPATH

2023-12-19T18:37:41Z

md-multipath has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig Cc: Jens Axboe Cc: Neil Brown Cc: Guoqing Jiang Cc: Mateusz Grzonka Cc: Jes Sorensen Signed-off-by: Song Liu Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20231214222107.2016042-3-song@kernel.org

md/md-multipath: remove rcu protection to access rdev from conf

2023-11-27T23:49:05Z

Because it's safe to accees rdev from conf: - If any spinlock is held, because synchronize_rcu() from md_kick_rdev_from_array() will prevent 'rdev' to be freed until spinlock is released; - If there is normal IO inflight, because mddev_suspend() will prevent rdev to be added or removed from array; And these will cover all the scenarios in md-multipath. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231125081604.3939938-6-yukuai1@huaweicloud.com

md: remove flag RemoveSynchronized

2023-11-27T23:49:04Z

rcu is not used correctly here, because synchronize_rcu() is called before replacing old value, for example: remove_and_add_spares // other path synchronize_rcu // called before replacing old value set_bit(RemoveSynchronized) rcu_read_lock() rdev = conf->mirros[].rdev pers->hot_remove_disk conf->mirros[].rdev = NULL; if (!test_bit(RemoveSynchronized)) synchronize_rcu /* * won't be called, and won't wait * for concurrent readers to be done. */ // access rdev after remove_and_add_spares() rcu_read_unlock() Fortunately, there is a separate rcu protection to prevent such rdev to be freed: md_kick_rdev_from_array //other path rcu_read_lock() rdev = conf->mirros[].rdev list_del_rcu(&rdev->same_set) rcu_read_unlock() /* * rdev can be removed from conf, but * rdev won't be freed. */ synchronize_rcu() free rdev Hence remove this useless flag and prepare to remove rcu protection to access rdev from 'conf'. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231125081604.3939938-2-yukuai1@huaweicloud.com

md/md-multipath: enable io accounting

2023-07-27T07:13:29Z

use md_account_bio() to enable io accounting, also make sure mddev_suspend() will wait for all io to be done. Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230621165110.1498313-7-yukuai1@huaweicloud.com

md: protect md_thread with rcu

2023-06-13T22:25:39Z

Currently, there are many places that md_thread can be accessed without protection, following are known scenarios that can cause null-ptr-dereference or uaf: 1) sync_thread that is allocated and started from md_start_sync() 2) mddev->thread can be accessed directly from timeout_store() and md_bitmap_daemon_work() 3) md_unregister_thread() from action_store(). Currently, a global spinlock 'pers_lock' is borrowed to protect 'mddev->thread' in some places, this problem can be fixed likewise, however, use a global lock for all the cases is not good. Fix this problem by protecting all md_thread with rcu. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230523021017.3048783-6-yukuai1@huaweicloud.com

md: remove most calls to bdevname

2022-05-23T06:07:21Z

Use the %pg format specifier to save on stack consumption and code size. Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2022-03-25T02:37:53Z

Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (qla2xxx, pm8001, libsas, smartpqi, scsi_debug, lpfc, iscsi, mpi3mr) plus minor updates and bug fixes. The high blast radius core update is the removal of write same, which affects block and several non-SCSI devices. The other big change, which is more local, is the removal of the SCSI pointer" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (281 commits) scsi: scsi_ioctl: Drop needless assignment in sg_io() scsi: bsg: Drop needless assignment in scsi_bsg_sg_io_fn() scsi: lpfc: Copyright updates for 14.2.0.0 patches scsi: lpfc: Update lpfc version to 14.2.0.0 scsi: lpfc: SLI path split: Refactor BSG paths scsi: lpfc: SLI path split: Refactor Abort paths scsi: lpfc: SLI path split: Refactor SCSI paths scsi: lpfc: SLI path split: Refactor CT paths scsi: lpfc: SLI path split: Refactor misc ELS paths scsi: lpfc: SLI path split: Refactor VMID paths scsi: lpfc: SLI path split: Refactor FDISC paths scsi: lpfc: SLI path split: Refactor LS_RJT paths scsi: lpfc: SLI path split: Refactor LS_ACC paths scsi: lpfc: SLI path split: Refactor the RSCN/SCR/RDF/EDC/FARPR paths scsi: lpfc: SLI path split: Refactor PLOGI/PRLI/ADISC/LOGO paths scsi: lpfc: SLI path split: Refactor base ELS paths and the FLOGI path scsi: lpfc: SLI path split: Introduce lpfc_prep_wqe scsi: lpfc: SLI path split: Refactor fast and slow paths to native SLI4 scsi: lpfc: SLI path split: Refactor lpfc_iocbq scsi: lpfc: Use kcalloc() ...

md-multipath: stop using bio_devname

2022-03-07T13:42:33Z

Use the %pg format specifier to save on stack consuption and code size. Signed-off-by: Christoph Hellwig Acked-by: Song Liu Reviewed-by: Chaitanya Kulkarni Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20220304180105.409765-7-hch@lst.de Signed-off-by: Jens Axboe

scsi: md: Remove WRITE_SAME support

2022-02-23T02:11:08Z

There are no more end-users of REQ_OP_WRITE_SAME left, so we can start deleting it. Link: https://lore.kernel.org/r/20220209082828.2629273-6-hch@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen

block: pass a block_device to bio_clone_fast

2022-02-04T14:43:18Z

Pass a block_device to bio_clone_fast and __bio_clone_fast and give the functions more suitable names. Signed-off-by: Christoph Hellwig Reviewed-by: Mike Snitzer Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.de Signed-off-by: Jens Axboe