kernel/linux.git/drivers/md/raid5-cache.c, branch linux-6.0.y

md/raid5-cache: Annotate pslot with __rcu notation

2022-08-02T23:14:32+00:00

radix_tree_lookup_slot() and radix_tree_replace_slot() API expect the slot returned and looked up to be marked with __rcu. Otherwise sparse warnings are generated: drivers/md/raid5-cache.c:2939:23: warning: incorrect type in assignment (different address spaces) drivers/md/raid5-cache.c:2939:23: expected void **pslot drivers/md/raid5-cache.c:2939:23: got void [noderef] __rcu ** Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu Signed-off-by: Jens Axboe

md/raid5-cache: Clear conf->log after finishing work

2022-08-02T23:14:31+00:00

A NULL pointer dereferlence on conf->log is seen randomly with the mdadm test 21raid5cache. Kasan reporst: BUG: KASAN: null-ptr-deref in r5l_reclaimable_space+0xf5/0x140 Read of size 8 at addr 0000000000000860 by task md0_reclaim/3086 Call Trace: dump_stack_lvl+0x5a/0x74 kasan_report.cold+0x5f/0x1a9 __asan_load8+0x69/0x90 r5l_reclaimable_space+0xf5/0x140 r5l_do_reclaim+0xf4/0x5e0 r5l_reclaim_thread+0x69/0x3b0 md_thread+0x1a2/0x2c0 kthread+0x177/0x1b0 ret_from_fork+0x22/0x30 This is caused by conf->log being cleared in r5l_exit_log() before stopping the reclaim thread. To fix this, clear conf->log after the reclaim_thread is unregistered and after flushing disable_writeback_work. Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu Signed-off-by: Jens Axboe

md/raid5-cache: Drop RCU usage of conf->log

2022-08-02T23:14:31+00:00

The only place that uses RCU to access conf->log is in r5l_log_disk_error(). This function is mostly used in the IO path and once with mddev_lock() held in raid5_change_consistency_policy(). It is known that the IO will be suspended before the log is freed and r5l_log_exit() is called with the mddev_lock() held. This should mean that conf->log can not be freed while the function is being called, so the RCU protection is not necessary. Drop the rcu_read_lock() as well as the synchronize_rcu() and rcu_assign_pointer() usage. Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu Signed-off-by: Jens Axboe

md/raid5-cache: Take mddev_lock in r5c_journal_mode_show()

2022-08-02T23:14:31+00:00

The mddev->lock spinlock doesn't protect against the removal of conf->log in r5l_exit_log() so conf->log may be freed before it is used. To fix this, take the mddev_lock() insteaad of the mddev->lock spinlock. Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu Signed-off-by: Jens Axboe

md/core: Combine two sync_page_io() arguments

2022-07-14T18:14:31+00:00

Improve uniformity in the kernel of handling of request operation and flags by passing these as a single argument. Cc: Song Liu Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-32-bvanassche@acm.org Signed-off-by: Jens Axboe

md: remove most calls to bdevname

2022-05-23T06:07:21+00:00

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

block: decouple REQ_OP_SECURE_ERASE from REQ_OP_DISCARD

2022-04-18T01:49:59+00:00

Secure erase is a very different operation from discard in that it is a data integrity operation vs hint. Fully split the limits and helper infrastructure to make the separation more clear. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Acked-by: Christoph Böhmwalder [drbd] Acked-by: Ryusuke Konishi [nifs2] Acked-by: Jaegeuk Kim [f2fs] Acked-by: Coly Li [bcache] Acked-by: David Sterba [btrfs] Acked-by: Chao Yu Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220415045258.199825-27-hch@lst.de Signed-off-by: Jens Axboe

block: remove QUEUE_FLAG_DISCARD

2022-04-18T01:49:59+00:00

Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Acked-by: Christoph Böhmwalder [drbd] Acked-by: Jan Höppner [s390] Acked-by: Coly Li [bcache] Acked-by: David Sterba [btrfs] Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe

raid5-cache: statically allocate the recovery ra bio

2022-03-09T06:55:09+00:00

There is no need to preallocate the bio and reset it when use. Just allocate it on-stack and use a bvec places next to the pages used for it. Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu

raid5-cache: fully initialize flush_bio when needed

2022-03-09T06:55:04+00:00

Stop using bio_reset and just initialize the bio fully when needed. Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu