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get rid of S_BIAS

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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>
This commit is contained in:
Al Viro
2010-03-22 08:53:19 -04:00
parent 389b8be6ef
commit b20bd1a5e7
3 changed files with 24 additions and 37 deletions
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28
fs/super.c
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@@ -93,7 +93,7 @@ static struct super_block *alloc_super(struct file_system_type *type)
* 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 put_super(struct super_block *sb)
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 @@ EXPORT_SYMBOL(deactivate_super);
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 @@ EXPORT_SYMBOL(deactivate_locked_super);
*/
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;
}