kernel/drivers/md/bcache/super.c, branch linux-6.5.y

bcache: Fix bcache device claiming

2023-06-23T22:10:04Z

Commit 2736e8eeb0cc ("block: use the holder as indication for exclusive opens") introduced a change that blkdev_put() has to get exclusive holder of the bdev as an argument. However it overlooked that register_bdev() and register_cache() overwrite the bdev->bd_holder field in the block device to point to the real owning object which was not available at the time we called blkdev_get_by_path(). Messing with bdev internals like this is a layering violation and it also causes blkdev_put() to issue warning about mismatching holders. Fix bcache to reopen the block device with appropriate holder once it is available which also restores the behavior that multiple bcache caches cannot claim the same device which was broken by commit 29499ab060fe ("bcache: don't pass a stack address to blkdev_get_by_path"). Fixes: 2736e8eeb0cc ("block: use the holder as indication for exclusive opens") Signed-off-by: Jan Kara Reviewed-by: Kent Overstreet Acked-by: Coly Li Link: https://lore.kernel.org/r/20230622164658.12861-2-jack@suse.cz Signed-off-by: Jens Axboe

bcache: Alloc holder object before async registration

2023-06-23T22:10:04Z

Allocate holder object (cache or cached_dev) before offloading the rest of the startup to async work. This will allow us to open the block block device with proper holder. Signed-off-by: Jan Kara Acked-by: Coly Li Reviewed-by: Kent Overstreet Link: https://lore.kernel.org/r/20230622164658.12861-1-jack@suse.cz Signed-off-by: Jens Axboe

bcache: Remove unnecessary NULL point check in node allocations

2023-06-15T13:30:43Z

Due to the previous fix of __bch_btree_node_alloc, the return value will never be a NULL pointer. So IS_ERR is enough to handle the failure situation. Fix it by replacing IS_ERR_OR_NULL check by an IS_ERR check. Fixes: cafe56359144 ("bcache: A block layer cache") Cc: stable@vger.kernel.org Signed-off-by: Zheng Wang Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20230615121223.22502-5-colyli@suse.de Signed-off-by: Jens Axboe

block: replace fmode_t with a block-specific type for block open flags

2023-06-12T14:04:05Z

The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: Christoph Hellwig Acked-by: Jack Wang [rnbd] Reviewed-by: Hannes Reinecke Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe

block: use the holder as indication for exclusive opens

2023-06-12T14:04:04Z

The current interface for exclusive opens is rather confusing as it requires both the FMODE_EXCL flag and a holder. Remove the need to pass FMODE_EXCL and just key off the exclusive open off a non-NULL holder. For blkdev_put this requires adding the holder argument, which provides better debug checking that only the holder actually releases the hold, but at the same time allows removing the now superfluous mode argument. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: David Sterba [btrfs] Acked-by: Jack Wang [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de Signed-off-by: Jens Axboe

bcache: don't pass a stack address to blkdev_get_by_path

2023-06-12T14:04:04Z

sb is just an on-stack pointer that can easily be reused by other calls. Switch to use the bcache-wide bcache_kobj instead as there is no need to claim per-bcache device anyway. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20230608110258.189493-13-hch@lst.de Signed-off-by: Jens Axboe

block: remove the unused mode argument to ->release

2023-06-12T14:04:04Z

The mode argument to the ->release block_device_operation is never used, so remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: Jack Wang [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-10-hch@lst.de Signed-off-by: Jens Axboe

block: pass a gendisk to ->open

2023-06-12T14:04:04Z

->open is only called on the whole device. Make that explicit by passing a gendisk instead of the block_device. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: Jack Wang [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-9-hch@lst.de Signed-off-by: Jens Axboe

block: introduce holder ops

2023-06-05T16:53:04Z

Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and installed in the block_device for exclusive claims. It will be used to allow the block layer to call back into the user of the block device for thing like notification of a removed device or a device resize. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Acked-by: Dave Chinner Reviewed-by: Dave Chinner Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de Signed-off-by: Jens Axboe

block/drivers: remove dead clear of random flag

2023-04-25T14:02:11Z

QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk", "brd", "nbd", "zram", and "bcache" since by default we don't set "QUEUE_FLAG_ADD_RANDOM" to MQ ops. Remove dead clear of QUEUE_FLAG_ADD_RANDOM in above listed drivers. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Sergey Senozhatsky #zram Link: https://lore.kernel.org/r/20230424234628.45544-2-kch@nvidia.com Signed-off-by: Jens Axboe