kernel/drivers/md/dm.h, branch linux-6.9.y

dm: shortcut the calls to linear_map and stripe_map

2023-10-06T23:09:25Z

Shortcut the calls to linear_map and stripe_map, so that they don't suffer the overhead of retpolines used for indirect calls. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm: remove stale/redundant dm_internal_{suspend,resume} prototypes in dm.h

2023-06-16T22:24:14Z

dm_internal_suspend() no longer exists. Signed-off-by: Mike Snitzer

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

dm: improve hash_locks sizing and hash function

2023-03-30T19:57:51Z

Both bufio and bio-prison-v1 use the identical model for splitting their respective locks and rbtrees. Improve dm_num_hash_locks() to distribute across more rbtrees to improve overall performance -- but the maximum number of locks/rbtrees is still 64. Also factor out a common hash function named dm_hash_locks_index(), the magic numbers used were determined to be best using this program: https://gist.github.com/jthornber/e05c47daa7b500c56dc339269c5467fc Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm: add dm_num_hash_locks()

2023-03-30T19:57:51Z

Simple helper to use when DM core code needs to appropriately size, based on num_online_cpus(), its data structures that split locks. dm_num_hash_locks() rounds up num_online_cpus() to next power of 2 but caps return at DM_HASH_LOCKS_MAX (64). This heuristic may evolve as warranted, but as-is it will serve as a more informed basis for sizing the sharded lock structs in dm-bufio's dm_buffer_cache (buffer_trees) and dm-bio-prison-v1's dm_bio_prison (prison_regions). Signed-off-by: Mike Snitzer

dm: correct block comments format.

2023-02-14T19:23:06Z

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: change "unsigned" to "unsigned int"

2023-02-14T19:23:06Z

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: send just one event on resize, not two

2023-02-14T19:22:27Z

Device mapper sends an uevent when the device is suspended, using the function set_capacity_and_notify. However, this causes a race condition with udev. Udev skips scanning dm devices that are suspended. If we send an uevent while we are suspended, udev will be racing with device mapper resume code. If the device mapper resume code wins the race, udev will process the uevent after the device is resumed and it will properly scan the device. However, if udev wins the race, it will receive the uevent, find out that the dm device is suspended and skip scanning the device. This causes bugs such as systemd unmounting the device - see https://bugzilla.redhat.com/show_bug.cgi?id=2158628 This commit fixes this race. We replace the function set_capacity_and_notify with set_capacity, so that the uevent is not sent at this point. In do_resume, we detect if the capacity has changed and we pass a boolean variable need_resize_uevent to dm_kobject_uevent. dm_kobject_uevent adds "RESIZE=1" to the uevent if need_resize_uevent is set. Signed-off-by: Mikulas Patocka Tested-by: Peter Rajnoha Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer

dm table: audit all dm_table_get_target() callers

2022-07-07T15:49:34Z

All callers of dm_table_get_target() are expected to do proper bounds checking on the index they pass. Move dm_table_get_target() to dm-core.h to make it extra clear that only DM core code should be using it. Switch it to be inlined while at it. Standardize all DM core callers to use the same for loop pattern and make associated variables as local as possible. Rename some variables (e.g. s/table/t/ and s/tgt/ti/) along the way. Signed-off-by: Mike Snitzer

dm: refactor dm_md_mempool allocation

2022-06-29T16:46:06Z

The current split between dm_table_alloc_md_mempools and dm_alloc_md_mempools is rather arbitrary, so merge the two into one easy to follow function. Signed-off-by: Christoph Hellwig Signed-off-by: Mike Snitzer