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author | Jakub Kicinski <kuba@kernel.org> | 2024-03-22 02:14:13 +0300 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2024-03-22 02:15:08 +0300 |
commit | 537c2e91d3549e5d6020bb0576cf9b54a845255f (patch) | |
tree | c09e8a1b7d733cde19b0c72678c28fb2bc97ff6b /fs/xfs/xfs_hooks.h | |
parent | 237bb5f7f7f55ec5f773469a974c61a49c298625 (diff) | |
parent | cba9ffdb9913dfe6be29f049ce920ce451ce7cc4 (diff) | |
download | linux-537c2e91d3549e5d6020bb0576cf9b54a845255f.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'fs/xfs/xfs_hooks.h')
-rw-r--r-- | fs/xfs/xfs_hooks.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/fs/xfs/xfs_hooks.h b/fs/xfs/xfs_hooks.h new file mode 100644 index 000000000000..60b8a5831536 --- /dev/null +++ b/fs/xfs/xfs_hooks.h @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2022-2024 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#ifndef XFS_HOOKS_H_ +#define XFS_HOOKS_H_ + +#ifdef CONFIG_XFS_LIVE_HOOKS +struct xfs_hooks { + struct blocking_notifier_head head; +}; + +/* + * If jump labels are enabled in Kconfig, the static key uses nop sleds and + * code patching to eliminate the overhead of taking the rwsem in + * blocking_notifier_call_chain when there are no hooks configured. If not, + * the static key per-call overhead is an atomic read. Most arches that can + * handle XFS also support jump labels. + * + * Note: Patching the kernel code requires taking the cpu hotplug lock. Other + * parts of the kernel allocate memory with that lock held, which means that + * XFS callers cannot hold any locks that might be used by memory reclaim or + * writeback when calling the static_branch_{inc,dec} functions. + */ +# define DEFINE_STATIC_XFS_HOOK_SWITCH(name) \ + static DEFINE_STATIC_KEY_FALSE(name) +# define xfs_hooks_switch_on(name) static_branch_inc(name) +# define xfs_hooks_switch_off(name) static_branch_dec(name) +# define xfs_hooks_switched_on(name) static_branch_unlikely(name) + +struct xfs_hook { + /* This must come at the start of the structure. */ + struct notifier_block nb; +}; + +typedef int (*xfs_hook_fn_t)(struct xfs_hook *hook, unsigned long action, + void *data); + +void xfs_hooks_init(struct xfs_hooks *chain); +int xfs_hooks_add(struct xfs_hooks *chain, struct xfs_hook *hook); +void xfs_hooks_del(struct xfs_hooks *chain, struct xfs_hook *hook); +int xfs_hooks_call(struct xfs_hooks *chain, unsigned long action, + void *priv); + +static inline void xfs_hook_setup(struct xfs_hook *hook, notifier_fn_t fn) +{ + hook->nb.notifier_call = fn; + hook->nb.priority = 0; +} + +#else + +struct xfs_hooks { /* empty */ }; + +# define DEFINE_STATIC_XFS_HOOK_SWITCH(name) +# define xfs_hooks_switch_on(name) ((void)0) +# define xfs_hooks_switch_off(name) ((void)0) +# define xfs_hooks_switched_on(name) (false) + +# define xfs_hooks_init(chain) ((void)0) +# define xfs_hooks_call(chain, val, priv) (NOTIFY_DONE) +#endif + +#endif /* XFS_HOOKS_H_ */ |