[PATCH 01/14] xfs: introduce CPU hotplug infrastructure
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2021-08-05 02:06:29
Subsystem:
cpu hotplug, filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Thomas Gleixner, Peter Zijlstra, Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: Dave Chinner <redacted> We need to move to per-cpu state for both deferred inode inactivation and CIL tracking, but to do that we need to handle CPUs being removed from the system by the hot-plug code. Introduce generic XFS infrastructure to handle CPU hotplug events that is set up at module init time and torn down at module exit time. Initially, we only need CPU dead notifications, so we only set up a callback for these notifications. The infrastructure can be updated in future for other CPU hotplug state machine notifications easily if ever needed. Signed-off-by: Dave Chinner <redacted> [djwong: rearrange some macros, fix function prototypes] Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> --- fs/xfs/xfs_super.c | 42 +++++++++++++++++++++++++++++++++++++++++- include/linux/cpuhotplug.h | 1 + 2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 36fc81e52dc2..d47fac7c8afd 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c@@ -2111,6 +2111,39 @@ xfs_destroy_workqueues(void) destroy_workqueue(xfs_alloc_wq); } +#ifdef CONFIG_HOTPLUG_CPU +static int +xfs_cpu_dead( + unsigned int cpu) +{ + return 0; +} + +static int __init +xfs_cpu_hotplug_init(void) +{ + int error; + + error = cpuhp_setup_state_nocalls(CPUHP_XFS_DEAD, "xfs:dead", NULL, + xfs_cpu_dead); + if (error < 0) + xfs_alert(NULL, +"Failed to initialise CPU hotplug, error %d. XFS is non-functional.", + error); + return error; +} + +static void +xfs_cpu_hotplug_destroy(void) +{ + cpuhp_remove_state_nocalls(CPUHP_XFS_DEAD); +} + +#else /* !CONFIG_HOTPLUG_CPU */ +static inline int xfs_cpu_hotplug_init(void) { return 0; } +static inline void xfs_cpu_hotplug_destroy(void) {} +#endif + STATIC int __init init_xfs_fs(void) {
@@ -2123,9 +2156,13 @@ init_xfs_fs(void) xfs_dir_startup(); + error = xfs_cpu_hotplug_init(); + if (error) + goto out; + error = xfs_init_zones(); if (error) - goto out; + goto out_destroy_hp; error = xfs_init_workqueues(); if (error)
@@ -2206,6 +2243,8 @@ init_xfs_fs(void) xfs_destroy_workqueues(); out_destroy_zones: xfs_destroy_zones(); + out_destroy_hp: + xfs_cpu_hotplug_destroy(); out: return error; }
@@ -2228,6 +2267,7 @@ exit_xfs_fs(void) xfs_destroy_workqueues(); xfs_destroy_zones(); xfs_uuid_table_free(); + xfs_cpu_hotplug_destroy(); } module_init(init_xfs_fs);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index f39b34b13871..439adc05be4e 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h@@ -52,6 +52,7 @@ enum cpuhp_state { CPUHP_FS_BUFF_DEAD, CPUHP_PRINTK_DEAD, CPUHP_MM_MEMCQ_DEAD, + CPUHP_XFS_DEAD, CPUHP_PERCPU_CNT_DEAD, CPUHP_RADIX_DEAD, CPUHP_PAGE_ALLOC,