diff options
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/Kconfig | 5 | ||||
| -rw-r--r-- | fs/xfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_hooks.c | 52 | ||||
| -rw-r--r-- | fs/xfs/xfs_hooks.h | 65 | ||||
| -rw-r--r-- | fs/xfs/xfs_linux.h | 1 |
5 files changed, 124 insertions, 0 deletions
diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig index 567fb37274d3..fa7eb3e2a248 100644 --- a/fs/xfs/Kconfig +++ b/fs/xfs/Kconfig @@ -124,11 +124,16 @@ config XFS_DRAIN_INTENTS bool select JUMP_LABEL if HAVE_ARCH_JUMP_LABEL +config XFS_LIVE_HOOKS + bool + select JUMP_LABEL if HAVE_ARCH_JUMP_LABEL + config XFS_ONLINE_SCRUB bool "XFS online metadata check support" default n depends on XFS_FS depends on TMPFS && SHMEM + select XFS_LIVE_HOOKS select XFS_DRAIN_INTENTS help If you say Y here you will be able to check metadata on a diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index 17af5bde5308..4597c0f19e8e 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -136,6 +136,7 @@ xfs-$(CONFIG_FS_DAX) += xfs_notify_failure.o endif xfs-$(CONFIG_XFS_DRAIN_INTENTS) += xfs_drain.o +xfs-$(CONFIG_XFS_LIVE_HOOKS) += xfs_hooks.o # online scrub/repair ifeq ($(CONFIG_XFS_ONLINE_SCRUB),y) diff --git a/fs/xfs/xfs_hooks.c b/fs/xfs/xfs_hooks.c new file mode 100644 index 000000000000..a58d1de2d37d --- /dev/null +++ b/fs/xfs/xfs_hooks.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2022-2024 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_ag.h" +#include "xfs_trace.h" + +/* Initialize a notifier chain. */ +void +xfs_hooks_init( + struct xfs_hooks *chain) +{ + BLOCKING_INIT_NOTIFIER_HEAD(&chain->head); +} + +/* Make it so a function gets called whenever we hit a certain hook point. */ +int +xfs_hooks_add( + struct xfs_hooks *chain, + struct xfs_hook *hook) +{ + ASSERT(hook->nb.notifier_call != NULL); + BUILD_BUG_ON(offsetof(struct xfs_hook, nb) != 0); + + return blocking_notifier_chain_register(&chain->head, &hook->nb); +} + +/* Remove a previously installed hook. */ +void +xfs_hooks_del( + struct xfs_hooks *chain, + struct xfs_hook *hook) +{ + blocking_notifier_chain_unregister(&chain->head, &hook->nb); +} + +/* Call a hook. Returns the NOTIFY_* value returned by the last hook. */ +int +xfs_hooks_call( + struct xfs_hooks *chain, + unsigned long val, + void *priv) +{ + return blocking_notifier_call_chain(&chain->head, val, priv); +} 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_ */ diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h index 75245932e0ad..8f07c9f6157f 100644 --- a/fs/xfs/xfs_linux.h +++ b/fs/xfs/xfs_linux.h @@ -81,6 +81,7 @@ typedef __u32 xfs_nlink_t; #include "xfs_buf.h" #include "xfs_message.h" #include "xfs_drain.h" +#include "xfs_hooks.h" #ifdef __BIG_ENDIAN #define XFS_NATIVE_HOST 1 |