On Wed, Aug 04, 2021 at 09:50:51PM +1000, Dave Chinner wrote:
>
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> The inode inactivation and CIL tracking percpu structures are
> per-xfs_mount structures. That means when we get a CPU dead
> notification, we need to then iterate all the per-cpu structure
> instances to process them. Rather than keeping linked lists of
> per-cpu structures in each subsystem, add a list of all xfs_mounts
> that the generic xfs_cpu_dead() function will iterate and call into
> each subsystem appropriately.
>
> This allows us to handle both per-mount and global XFS percpu state
> from xfs_cpu_dead(), and avoids the need to link subsystem
> structures that can be easily found from the xfs_mount into their
> own global lists.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
> fs/xfs/xfs_mount.h | 1 +
> fs/xfs/xfs_super.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 42 insertions(+)
>
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index c78b63fe779a..ed7064596f94 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -82,6 +82,7 @@ typedef struct xfs_mount {
> xfs_buftarg_t *m_ddev_targp; /* saves taking the address */
> xfs_buftarg_t *m_logdev_targp;/* ptr to log device */
> xfs_buftarg_t *m_rtdev_targp; /* ptr to rt device */
> + struct list_head m_mount_list; /* global mount list */
> /*
> * Optional cache of rt summary level per bitmap block with the
> * invariant that m_rsum_cache[bbno] <= the minimum i for which
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index ffe1ecd048db..c27df85212d4 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -49,6 +49,28 @@ static struct kset *xfs_kset; /* top-level xfs sysfs dir */
> static struct xfs_kobj xfs_dbg_kobj; /* global debug sysfs attrs */
> #endif
>
> +#ifdef CONFIG_HOTPLUG_CPU
> +static LIST_HEAD(xfs_mount_list);
> +static DEFINE_SPINLOCK(xfs_mount_list_lock);
> +
> +static inline void xfs_mount_list_add(struct xfs_mount *mp)
> +{
> + spin_lock(&xfs_mount_list_lock);
> + list_add(&mp->m_mount_list, &xfs_mount_list);
> + spin_unlock(&xfs_mount_list_lock);
> +}
> +
> +static inline void xfs_mount_list_del(struct xfs_mount *mp)
> +{
> + spin_lock(&xfs_mount_list_lock);
> + list_del(&mp->m_mount_list);
> + spin_unlock(&xfs_mount_list_lock);
> +}
> +#else /* !CONFIG_HOTPLUG_CPU */
> +static inline void xfs_mount_list_add(struct xfs_mount *mp) {}
> +static inline void xfs_mount_list_del(struct xfs_mount *mp) {}
> +#endif
> +
> enum xfs_dax_mode {
> XFS_DAX_INODE = 0,
> XFS_DAX_ALWAYS = 1,
> @@ -988,6 +1010,7 @@ xfs_fs_put_super(
>
> xfs_freesb(mp);
> free_percpu(mp->m_stats.xs_stats);
> + xfs_mount_list_del(mp);
> xfs_destroy_percpu_counters(mp);
> xfs_destroy_mount_workqueues(mp);
> xfs_close_devices(mp);
> @@ -1359,6 +1382,8 @@ xfs_fs_fill_super(
> if (error)
> goto out_destroy_workqueues;
>
> + xfs_mount_list_add(mp);
> +
> /* Allocate stats memory before we do operations that might use it */
> mp->m_stats.xs_stats = alloc_percpu(struct xfsstats);
> if (!mp->m_stats.xs_stats) {
> @@ -1567,6 +1592,7 @@ xfs_fs_fill_super(
> out_free_stats:
> free_percpu(mp->m_stats.xs_stats);
> out_destroy_counters:
> + xfs_mount_list_del(mp);
> xfs_destroy_percpu_counters(mp);
> out_destroy_workqueues:
> xfs_destroy_mount_workqueues(mp);
> @@ -2061,10 +2087,20 @@ xfs_destroy_workqueues(void)
> destroy_workqueue(xfs_alloc_wq);
> }
>
> +#ifdef CONFIG_HOTPLUG_CPU
> static int
> xfs_cpu_dead(
> unsigned int cpu)
> {
> + struct xfs_mount *mp, *n;
> +
> + spin_lock(&xfs_mount_list_lock);
> + list_for_each_entry_safe(mp, n, &xfs_mount_list, m_mount_list) {
> + spin_unlock(&xfs_mount_list_lock);
> + /* xfs_subsys_dead(mp, cpu); */
> + spin_lock(&xfs_mount_list_lock);
> + }
> + spin_unlock(&xfs_mount_list_lock);
> return 0;
> }
>
> @@ -2090,6 +2126,11 @@ xfs_cpu_hotplug_destroy(void)
> cpuhp_remove_state_nocalls(CPUHP_XFS_DEAD);
> }
>
> +#else /* !CONFIG_HOTPLUG_CPU */
> +static inline int xfs_cpu_hotplug_init(struct xfs_cil *cil) { return 0; }
> +static inline void xfs_cpu_hotplug_destroy(struct xfs_cil *cil) {}
void arguments here, right?
> +#endif
Nit: I think this ifdef stuff belongs in the previous patch. Will fix
it when I drag this into my tree.
--D
> +
> STATIC int __init
> init_xfs_fs(void)
> {
