allow attaching fs_pin to a group not associated with some superblock

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-01-11 10:57:27 -05:00
parent 3b994d98a8
commit fdab684d72
4 changed files with 17 additions and 10 deletions

View File

@ -14,14 +14,20 @@ void pin_remove(struct fs_pin *pin)
spin_unlock(&pin_lock);
}
void pin_insert(struct fs_pin *pin, struct vfsmount *m)
void pin_insert_group(struct fs_pin *pin, struct vfsmount *m, struct hlist_head *p)
{
spin_lock(&pin_lock);
hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
if (p)
hlist_add_head(&pin->s_list, p);
hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
spin_unlock(&pin_lock);
}
void pin_insert(struct fs_pin *pin, struct vfsmount *m)
{
pin_insert_group(pin, m, &m->mnt_sb->s_pins);
}
void mnt_pin_kill(struct mount *m)
{
while (1) {
@ -38,18 +44,18 @@ void mnt_pin_kill(struct mount *m)
}
}
void sb_pin_kill(struct super_block *sb)
void group_pin_kill(struct hlist_head *p)
{
while (1) {
struct hlist_node *p;
struct hlist_node *q;
struct fs_pin *pin;
rcu_read_lock();
p = ACCESS_ONCE(sb->s_pins.first);
if (!p) {
q = ACCESS_ONCE(p->first);
if (!q) {
rcu_read_unlock();
break;
}
pin = hlist_entry(p, struct fs_pin, s_list);
pin = hlist_entry(q, struct fs_pin, s_list);
pin->kill(pin);
}
}

View File

@ -145,7 +145,7 @@ extern const struct file_operations pipefifo_fops;
/*
* fs_pin.c
*/
extern void sb_pin_kill(struct super_block *sb);
extern void group_pin_kill(struct hlist_head *p);
extern void mnt_pin_kill(struct mount *m);
/*

View File

@ -706,9 +706,9 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY);
if (remount_ro) {
if (sb->s_pins.first) {
if (!hlist_empty(&sb->s_pins)) {
up_write(&sb->s_umount);
sb_pin_kill(sb);
group_pin_kill(&sb->s_pins);
down_write(&sb->s_umount);
if (!sb->s_root)
return 0;

View File

@ -7,4 +7,5 @@ struct fs_pin {
};
void pin_remove(struct fs_pin *);
void pin_insert_group(struct fs_pin *, struct vfsmount *, struct hlist_head *);
void pin_insert(struct fs_pin *, struct vfsmount *);