diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
| commit | 3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch) | |
| tree | b767d7f6e26bc64334d3f14f8422d187239dc45d /drivers/md/dm-path-selector.h | |
| download | linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip | |
Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe:
- Fix a task_work add use-after-free with SQPOLL.
The sqpoll thread could pop and complete the last request while
io_req_normal_work_add() was still looking at them after the mpscq
push.
Use the same approach as DEFER_TASKRUN to protect from that, holding
an RCU read lock across the add, and have exit wait for an RCU grace
period for SQPOLL rings as well.
- CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
rings
- Mark the source filter table as COW when cloning bpf filters, so
registering another filter on the source doesn't modify the shared
table in place
- Initialize the task context before running the BPF loop
- Requeue zcrx multishot receives stopped by a local resource
- End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)
* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: fix task_work add use-after-free with SQPOLL
io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
io_uring/zcrx: requeue multishot receives stopped by a local resource
io_uring: initialize task context before running the BPF loop
io_uring: zero big_cqe for aux CQEs on CQE32 rings
io_uring: fix free entry check for 32b CQEs on CQE32 rings
io_uring: only post the dummy skip CQE on CQE_MIXED rings
io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'drivers/md/dm-path-selector.h')
| -rw-r--r-- | drivers/md/dm-path-selector.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/md/dm-path-selector.h b/drivers/md/dm-path-selector.h new file mode 100644 index 000000000..7b2270532 --- /dev/null +++ b/drivers/md/dm-path-selector.h @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2003 Sistina Software. + * Copyright (C) 2004 Red Hat, Inc. All rights reserved. + * + * Module Author: Heinz Mauelshagen + * + * This file is released under the GPL. + * + * Path-Selector registration. + */ + +#ifndef DM_PATH_SELECTOR_H +#define DM_PATH_SELECTOR_H + +#include <linux/device-mapper.h> + +#include "dm-mpath.h" + +/* + * We provide an abstraction for the code that chooses which path + * to send some io down. + */ +struct path_selector_type; +struct path_selector { + struct path_selector_type *type; + void *context; +}; + +/* + * If a path selector uses this flag, a high resolution timer is used + * (via ktime_get_ns) to account for IO start time in BIO-based mpath. + * This improves performance of some path selectors (i.e. HST), in + * exchange for slightly higher overhead when submitting the BIO. + * The extra cost is usually offset by improved path selection for + * some benchmarks. + * + * This has no effect for request-based mpath, since it already uses a + * higher precision timer by default. + */ +#define DM_PS_USE_HR_TIMER 0x00000001 +#define dm_ps_use_hr_timer(type) ((type)->features & DM_PS_USE_HR_TIMER) + +/* Information about a path selector type */ +struct path_selector_type { + char *name; + struct module *module; + + unsigned int features; + unsigned int table_args; + unsigned int info_args; + + /* + * Constructs a path selector object, takes custom arguments + */ + int (*create)(struct path_selector *ps, unsigned int argc, char **argv); + void (*destroy)(struct path_selector *ps); + + /* + * Add an opaque path object, along with some selector specific + * path args (eg, path priority). + */ + int (*add_path)(struct path_selector *ps, struct dm_path *path, + int argc, char **argv, char **error); + + /* + * Chooses a path for this io, if no paths are available then + * NULL will be returned. + */ + struct dm_path *(*select_path)(struct path_selector *ps, size_t nr_bytes); + + /* + * Notify the selector that a path has failed. + */ + void (*fail_path)(struct path_selector *ps, struct dm_path *p); + + /* + * Ask selector to reinstate a path. + */ + int (*reinstate_path)(struct path_selector *ps, struct dm_path *p); + + /* + * Table content based on parameters added in ps_add_path_fn + * or path selector status + */ + int (*status)(struct path_selector *ps, struct dm_path *path, + status_type_t type, char *result, unsigned int maxlen); + + int (*start_io)(struct path_selector *ps, struct dm_path *path, + size_t nr_bytes); + int (*end_io)(struct path_selector *ps, struct dm_path *path, + size_t nr_bytes, u64 start_time); +}; + +/* Register a path selector */ +int dm_register_path_selector(struct path_selector_type *type); + +/* Unregister a path selector */ +void dm_unregister_path_selector(struct path_selector_type *type); + +/* Returns a registered path selector type */ +struct path_selector_type *dm_get_path_selector(const char *name); + +/* Releases a path selector */ +void dm_put_path_selector(struct path_selector_type *pst); + +#endif |
