xfs: introduce all-mounts list for cpu hotplug notifications
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@redhat.com>
[djwong: expand some comments about mount list setup ordering rules]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index d47fac7..c2c9c02 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,
@@ -1038,6 +1060,7 @@ 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);
@@ -1409,6 +1432,13 @@ xfs_fs_fill_super(
if (error)
goto out_destroy_workqueues;
+ /*
+ * All percpu data structures requiring cleanup when a cpu goes offline
+ * must be allocated before adding this @mp to the cpu-dead handler's
+ * mount list.
+ */
+ 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) {
@@ -1617,6 +1647,7 @@ 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);
@@ -2116,6 +2147,15 @@ 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;
}
