Leave superblocks on s_list until the end
We used to remove from s_list and s_instances at the same
time. So let's *not* do the former and skip superblocks
that have empty s_instances in the loops over s_list.
The next step, of course, will be to get rid of rescan logics
in those loops.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index 157657b3..0390461 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -135,6 +135,7 @@
int ret = 0;
if (!--sb->s_count) {
+ list_del_init(&sb->s_list);
destroy_super(sb);
ret = 1;
}
@@ -151,7 +152,7 @@
int __put_super_and_need_restart(struct super_block *sb)
{
/* check for race with generic_shutdown_super() */
- if (list_empty(&sb->s_list)) {
+ if (list_empty(&sb->s_instances)) {
/* super block is removed, need to restart... */
__put_super(sb);
return 1;
@@ -308,8 +309,7 @@
}
spin_lock(&sb_lock);
/* should be initialized for __put_super_and_need_restart() */
- list_del_init(&sb->s_list);
- list_del(&sb->s_instances);
+ list_del_init(&sb->s_instances);
spin_unlock(&sb_lock);
up_write(&sb->s_umount);
}
@@ -400,6 +400,8 @@
spin_lock(&sb_lock);
restart:
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
if (sb->s_op->write_super && sb->s_dirt) {
sb->s_count++;
spin_unlock(&sb_lock);
@@ -435,6 +437,8 @@
spin_lock(&sb_lock);
rescan:
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
if (sb->s_bdev == bdev) {
sb->s_count++;
spin_unlock(&sb_lock);
@@ -471,6 +475,8 @@
spin_lock(&sb_lock);
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
if (sb->s_bdev != bdev)
continue;
@@ -490,6 +496,8 @@
spin_lock(&sb_lock);
rescan:
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
if (sb->s_dev == dev) {
sb->s_count++;
spin_unlock(&sb_lock);
@@ -600,6 +608,8 @@
spin_lock(&sb_lock);
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
sb->s_count++;
spin_unlock(&sb_lock);
down_write(&sb->s_umount);