[PATCH] uml spinlock breakage

[pandora-kernel.git] / fs / super.c

diff --git a/fs/super.c b/fs/super.c
index 573bcc8..6e57ee2 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -341,20 +341,22 @@ static inline void write_super(struct super_block *sb)
  */
 void sync_supers(void)
 {
-       struct super_block * sb;
-restart:
+       struct super_block *sb;
+
        spin_lock(&sb_lock);
-       sb = sb_entry(super_blocks.next);
-       while (sb != sb_entry(&super_blocks))
+restart:
+       list_for_each_entry(sb, &super_blocks, s_list) {
                if (sb->s_dirt) {
                        sb->s_count++;
                        spin_unlock(&sb_lock);
                        down_read(&sb->s_umount);
                        write_super(sb);
-                       drop_super(sb);
-                       goto restart;
-               } else
-                       sb = sb_entry(sb->s_list.next);
+                       up_read(&sb->s_umount);
+                       spin_lock(&sb_lock);
+                       if (__put_super_and_need_restart(sb))
+                               goto restart;
+               }
+       }
        spin_unlock(&sb_lock);
 }
 
@@ -381,20 +383,16 @@ void sync_filesystems(int wait)
 
        down(&mutex);           /* Could be down_interruptible */
        spin_lock(&sb_lock);
-       for (sb = sb_entry(super_blocks.next); sb != sb_entry(&super_blocks);
-                       sb = sb_entry(sb->s_list.next)) {
+       list_for_each_entry(sb, &super_blocks, s_list) {
                if (!sb->s_op->sync_fs)
                        continue;
                if (sb->s_flags & MS_RDONLY)
                        continue;
                sb->s_need_sync_fs = 1;
        }
-       spin_unlock(&sb_lock);
 
 restart:
-       spin_lock(&sb_lock);
-       for (sb = sb_entry(super_blocks.next); sb != sb_entry(&super_blocks);
-                       sb = sb_entry(sb->s_list.next)) {
+       list_for_each_entry(sb, &super_blocks, s_list) {
                if (!sb->s_need_sync_fs)
                        continue;
                sb->s_need_sync_fs = 0;
@@ -405,8 +403,11 @@ restart:
                down_read(&sb->s_umount);
                if (sb->s_root && (wait || sb->s_dirt))
                        sb->s_op->sync_fs(sb, wait);
-               drop_super(sb);
-               goto restart;
+               up_read(&sb->s_umount);
+               /* restart only when sb is no longer on the list */
+               spin_lock(&sb_lock);
+               if (__put_super_and_need_restart(sb))
+                       goto restart;
        }
        spin_unlock(&sb_lock);
        up(&mutex);
@@ -422,21 +423,25 @@ restart:
 
 struct super_block * get_super(struct block_device *bdev)
 {
-       struct list_head *p;
+       struct super_block *sb;
+
        if (!bdev)
                return NULL;
-rescan:
+
        spin_lock(&sb_lock);
-       list_for_each(p, &super_blocks) {
-               struct super_block *s = sb_entry(p);
-               if (s->s_bdev == bdev) {
-                       s->s_count++;
+rescan:
+       list_for_each_entry(sb, &super_blocks, s_list) {
+               if (sb->s_bdev == bdev) {
+                       sb->s_count++;
                        spin_unlock(&sb_lock);
-                       down_read(&s->s_umount);
-                       if (s->s_root)
-                               return s;
-                       drop_super(s);
-                       goto rescan;
+                       down_read(&sb->s_umount);
+                       if (sb->s_root)
+                               return sb;
+                       up_read(&sb->s_umount);
+                       /* restart only when sb is no longer on the list */
+                       spin_lock(&sb_lock);
+                       if (__put_super_and_need_restart(sb))
+                               goto rescan;
                }
        }
        spin_unlock(&sb_lock);
@@ -447,20 +452,22 @@ EXPORT_SYMBOL(get_super);
  
 struct super_block * user_get_super(dev_t dev)
 {
-       struct list_head *p;
+       struct super_block *sb;
 
-rescan:
        spin_lock(&sb_lock);
-       list_for_each(p, &super_blocks) {
-               struct super_block *s = sb_entry(p);
-               if (s->s_dev ==  dev) {
-                       s->s_count++;
+rescan:
+       list_for_each_entry(sb, &super_blocks, s_list) {
+               if (sb->s_dev ==  dev) {
+                       sb->s_count++;
                        spin_unlock(&sb_lock);
-                       down_read(&s->s_umount);
-                       if (s->s_root)
-                               return s;
-                       drop_super(s);
-                       goto rescan;
+                       down_read(&sb->s_umount);
+                       if (sb->s_root)
+                               return sb;
+                       up_read(&sb->s_umount);
+                       /* restart only when sb is no longer on the list */
+                       spin_lock(&sb_lock);
+                       if (__put_super_and_need_restart(sb))
+                               goto rescan;
                }
        }
        spin_unlock(&sb_lock);
@@ -833,7 +840,6 @@ do_kern_mount(const char *fstype, int flags, const char *name, void *data)
        mnt->mnt_root = dget(sb->s_root);
        mnt->mnt_mountpoint = sb->s_root;
        mnt->mnt_parent = mnt;
-       mnt->mnt_namespace = current->namespace;
        up_write(&sb->s_umount);
        free_secdata(secdata);
        put_filesystem(type);