patch intoducing IOctl #21 allowing for waiting for completion of deleted subvol recovery

Commit Message

David Nicol Oct. 6, 2010, 3:05 p.m. UTC

None

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e9bf864..a350b75 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -895,6 +895,7 @@  struct btrfs_fs_info {
 	struct list_head trans_list;
 	struct list_head hashers;
 	struct list_head dead_roots;
+	wait_queue_head_t cleaner_notification_registration;
 	struct list_head caching_block_groups;
 
 	spinlock_t delayed_iput_lock;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 34f7c37..6a35257 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1451,6 +1451,7 @@  static int cleaner_kthread(void *arg)
 		    mutex_trylock(&root->fs_info->cleaner_mutex)) {
 			btrfs_run_delayed_iputs(root);
 			btrfs_clean_old_snapshots(root);
+			wake_up_all(&root->fs_info->cleaner_notification_registration);
 			mutex_unlock(&root->fs_info->cleaner_mutex);
 		}
 
@@ -1581,6 +1582,7 @@  struct btrfs_root *open_ctree(struct super_block *sb,
 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
 	INIT_LIST_HEAD(&fs_info->trans_list);
 	INIT_LIST_HEAD(&fs_info->dead_roots);
+	init_waitqueue_head(&fs_info->cleaner_notification_registration);
 	INIT_LIST_HEAD(&fs_info->delayed_iputs);
 	INIT_LIST_HEAD(&fs_info->hashers);
 	INIT_LIST_HEAD(&fs_info->delalloc_inodes);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 9254b3d..9f5a525 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1212,6 +1212,46 @@  static noinline int btrfs_ioctl_ino_lookup(struct file *file,
 	return ret;
 }
 
+static int btrfs_ioctl_cleaner_wait(struct btrfs_root *root, void __user *arg)
+{
+        struct btrfs_ioctl_cleaner_wait_args *bicwa;
+        long remainingjiffies;
+        int err;
+
+	bicwa = memdup_user(arg, sizeof(*bicwa));
+	if (IS_ERR(bicwa))
+		return PTR_ERR(bicwa);
+
+        err = -EINVAL;
+
+        if (bicwa->ms > 0)
+	{
+            remainingjiffies = wait_event_interruptible_timeout(
+                 root->fs_info->cleaner_notification_registration,
+                 list_empty(&root->fs_info->dead_roots),
+                 msecs_to_jiffies(bicwa->ms)
+            );
+            if (remainingjiffies > 0)
+                  err = 0;
+            else if (remainingjiffies < 0 )
+                  err = -EAGAIN;
+            else
+                  err = -ETIME;
+        }
+	else
+	{
+            err = wait_event_interruptible(
+                 root->fs_info->cleaner_notification_registration,
+                 list_empty(&root->fs_info->dead_roots)
+            );
+        };
+
+	kfree(bicwa);
+        return err;
+
+}
+
+
 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 					     void __user *arg)
 {
@@ -2003,6 +2043,8 @@  long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_snap_create(file, argp, 1);
 	case BTRFS_IOC_SNAP_DESTROY:
 		return btrfs_ioctl_snap_destroy(file, argp);
+	case BTRFS_IOC_CLEANER_WAIT:
+		return btrfs_ioctl_cleaner_wait(root, argp);
 	case BTRFS_IOC_DEFAULT_SUBVOL:
 		return btrfs_ioctl_default_subvol(file, argp);
 	case BTRFS_IOC_DEFRAG:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 424694a..cd15a50 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -138,6 +138,10 @@  struct btrfs_ioctl_space_args {
 	struct btrfs_ioctl_space_info spaces[0];
 };
 
+struct btrfs_ioctl_cleaner_wait_args{
+        unsigned long ms;
+};
+
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
 				   struct btrfs_ioctl_vol_args)
 #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -178,4 +182,6 @@  struct btrfs_ioctl_space_args {
 #define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, u64)
 #define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \
 				    struct btrfs_ioctl_space_args)
+#define BTRFS_IOC_CLEANER_WAIT _IOW(BTRFS_IOCTL_MAGIC, 21, \
+				    struct btrfs_ioctl_cleaner_wait_args)
 #endif