btrfs: plumb fs_info into btrfs_work

In order to provide an fsid for trace events, we'll need a btrfs_fs_info
pointer.  The most lightweight way to do that for btrfs_work structures
is to associate it with the __btrfs_workqueue structure.  Each queued
btrfs_work structure has a workqueue associated with it, so that's
a natural fit.  It's a privately defined structures, so we add accessors
to retrieve the fs_info pointer.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 25 insertions, 6 deletions

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 5fb60ea..e0f071f 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -34,6 +34,10 @@
 
 struct __btrfs_workqueue {
 	struct workqueue_struct *normal_wq;
+
+	/* File system this workqueue services */
+	struct btrfs_fs_info *fs_info;
+
 	/* List head pointing to ordered work list */
 	struct list_head ordered_list;
 
@@ -70,6 +74,18 @@ void btrfs_##name(struct work_struct *arg)				\
 	normal_work_helper(work);					\
 }
 
+struct btrfs_fs_info *
+btrfs_workqueue_owner(struct __btrfs_workqueue *wq)
+{
+	return wq->fs_info;
+}
+
+struct btrfs_fs_info *
+btrfs_work_owner(struct btrfs_work *work)
+{
+	return work->wq->fs_info;
+}
+
 BTRFS_WORK_HELPER(worker_helper);
 BTRFS_WORK_HELPER(delalloc_helper);
 BTRFS_WORK_HELPER(flush_delalloc_helper);
@@ -94,14 +110,15 @@ BTRFS_WORK_HELPER(scrubnc_helper);
 BTRFS_WORK_HELPER(scrubparity_helper);
 
 static struct __btrfs_workqueue *
-__btrfs_alloc_workqueue(const char *name, unsigned int flags, int limit_active,
-			 int thresh)
+__btrfs_alloc_workqueue(struct btrfs_fs_info *fs_info, const char *name,
+			unsigned int flags, int limit_active, int thresh)
 {
 	struct __btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_KERNEL);
 
 	if (!ret)
 		return NULL;
 
+	ret->fs_info = fs_info;
 	ret->limit_active = limit_active;
 	atomic_set(&ret->pending, 0);
 	if (thresh == 0)
@@ -143,7 +160,8 @@ __btrfs_alloc_workqueue(const char *name, unsigned int flags, int limit_active,
 static inline void
 __btrfs_destroy_workqueue(struct __btrfs_workqueue *wq);
 
-struct btrfs_workqueue *btrfs_alloc_workqueue(const char *name,
+struct btrfs_workqueue *btrfs_alloc_workqueue(struct btrfs_fs_info *fs_info,
+					      const char *name,
 					      unsigned int flags,
 					      int limit_active,
 					      int thresh)
@@ -153,7 +171,8 @@ struct btrfs_workqueue *btrfs_alloc_workqueue(const char *name,
 	if (!ret)
 		return NULL;
 
-	ret->normal = __btrfs_alloc_workqueue(name, flags & ~WQ_HIGHPRI,
+	ret->normal = __btrfs_alloc_workqueue(fs_info, name,
+					      flags & ~WQ_HIGHPRI,
 					      limit_active, thresh);
 	if (!ret->normal) {
 		kfree(ret);
@@ -161,8 +180,8 @@ struct btrfs_workqueue *btrfs_alloc_workqueue(const char *name,
 	}
 
 	if (flags & WQ_HIGHPRI) {
-		ret->high = __btrfs_alloc_workqueue(name, flags, limit_active,
-						    thresh);
+		ret->high = __btrfs_alloc_workqueue(fs_info, name, flags,
+						    limit_active, thresh);
 		if (!ret->high) {
 			__btrfs_destroy_workqueue(ret->normal);
 			kfree(ret);