percpu_up_write(sb->s_writers.rw_sem + level);
}
+static int wait_for_partially_frozen(struct super_block *sb)
+{
+ int ret = 0;
+
+ do {
+ unsigned short old = sb->s_writers.frozen;
+
+ up_write(&sb->s_umount);
+ ret = wait_var_event_killable(&sb->s_writers.frozen,
+ sb->s_writers.frozen != old);
+ down_write(&sb->s_umount);
+ } while (ret == 0 &&
+ sb->s_writers.frozen != SB_UNFROZEN &&
+ sb->s_writers.frozen != SB_FREEZE_COMPLETE);
+
+ return ret;
+}
+
/**
* freeze_super - lock the filesystem and force it into a consistent state
* @sb: the super to lock
atomic_inc(&sb->s_active);
down_write(&sb->s_umount);
+retry:
if (sb->s_writers.frozen == SB_FREEZE_COMPLETE) {
if (sb->s_writers.freeze_holders & who) {
deactivate_locked_super(sb);
}
if (sb->s_writers.frozen != SB_UNFROZEN) {
- deactivate_locked_super(sb);
- return -EBUSY;
+ ret = wait_for_partially_frozen(sb);
+ if (ret) {
+ deactivate_locked_super(sb);
+ return ret;
+ }
+
+ goto retry;
}
if (!(sb->s_flags & SB_BORN)) {
/* Nothing to do really... */
sb->s_writers.freeze_holders |= who;
sb->s_writers.frozen = SB_FREEZE_COMPLETE;
+ wake_up_var(&sb->s_writers.frozen);
up_write(&sb->s_umount);
return 0;
}
if (ret) {
sb->s_writers.frozen = SB_UNFROZEN;
sb_freeze_unlock(sb, SB_FREEZE_PAGEFAULT);
+ wake_up_var(&sb->s_writers.frozen);
deactivate_locked_super(sb);
return ret;
}
"VFS:Filesystem freeze failed\n");
sb->s_writers.frozen = SB_UNFROZEN;
sb_freeze_unlock(sb, SB_FREEZE_FS);
+ wake_up_var(&sb->s_writers.frozen);
deactivate_locked_super(sb);
return ret;
}
*/
sb->s_writers.freeze_holders |= who;
sb->s_writers.frozen = SB_FREEZE_COMPLETE;
+ wake_up_var(&sb->s_writers.frozen);
lockdep_sb_freeze_release(sb);
up_write(&sb->s_umount);
return 0;
if (sb_rdonly(sb)) {
sb->s_writers.freeze_holders &= ~who;
sb->s_writers.frozen = SB_UNFROZEN;
+ wake_up_var(&sb->s_writers.frozen);
goto out;
}
sb->s_writers.freeze_holders &= ~who;
sb->s_writers.frozen = SB_UNFROZEN;
+ wake_up_var(&sb->s_writers.frozen);
sb_freeze_unlock(sb, SB_FREEZE_FS);
out:
deactivate_locked_super(sb);