get rid of S_BIAS
use atomic_inc_not_zero(&sb->s_active) instead of playing games with
checking ->s_count > S_BIAS
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index d8c8b1d..bc734f8 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -93,7 +93,7 @@
* subclass.
*/
down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
- s->s_count = S_BIAS;
+ s->s_count = 1;
atomic_set(&s->s_active, 1);
mutex_init(&s->s_vfs_rename_mutex);
mutex_init(&s->s_dquot.dqio_mutex);
@@ -189,9 +189,7 @@
void deactivate_super(struct super_block *s)
{
struct file_system_type *fs = s->s_type;
- if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
- s->s_count -= S_BIAS-1;
- spin_unlock(&sb_lock);
+ if (atomic_dec_and_test(&s->s_active)) {
vfs_dq_off(s, 0);
down_write(&s->s_umount);
fs->kill_sb(s);
@@ -216,9 +214,7 @@
void deactivate_locked_super(struct super_block *s)
{
struct file_system_type *fs = s->s_type;
- if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
- s->s_count -= S_BIAS-1;
- spin_unlock(&sb_lock);
+ if (atomic_dec_and_test(&s->s_active)) {
vfs_dq_off(s, 0);
fs->kill_sb(s);
put_filesystem(fs);
@@ -243,21 +239,19 @@
*/
static int grab_super(struct super_block *s) __releases(sb_lock)
{
+ if (atomic_inc_not_zero(&s->s_active)) {
+ spin_unlock(&sb_lock);
+ down_write(&s->s_umount);
+ return 1;
+ }
+ /* it's going away */
s->s_count++;
spin_unlock(&sb_lock);
+ /* usually that'll be enough for it to die... */
down_write(&s->s_umount);
- if (s->s_root) {
- spin_lock(&sb_lock);
- if (s->s_count > S_BIAS) {
- atomic_inc(&s->s_active);
- s->s_count--;
- spin_unlock(&sb_lock);
- return 1;
- }
- spin_unlock(&sb_lock);
- }
up_write(&s->s_umount);
put_super(s);
+ /* ... but in case it wasn't, let's at least yield() */
yield();
return 0;
}
