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>

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);

fs/btrfs/async-thread.h

@@ -21,6 +21,7 @@
 #define __BTRFS_ASYNC_THREAD_
 #include <linux/workqueue.h>
 
+struct btrfs_fs_info;
 struct btrfs_workqueue;
 /* Internal use only */
 struct __btrfs_workqueue;
@@ -67,7 +68,8 @@ BTRFS_WORK_HELPER_PROTO(scrubnc_helper);
 BTRFS_WORK_HELPER_PROTO(scrubparity_helper);
 
 
-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);
@@ -80,4 +82,6 @@ void btrfs_queue_work(struct btrfs_workqueue *wq,
 void btrfs_destroy_workqueue(struct btrfs_workqueue *wq);
 void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int max);
 void btrfs_set_work_high_priority(struct btrfs_work *work);
+struct btrfs_fs_info *btrfs_work_owner(struct btrfs_work *work);
+struct btrfs_fs_info *btrfs_workqueue_owner(struct __btrfs_workqueue *wq);
 #endif

fs/btrfs/disk-io.c

@@ -2310,17 +2310,19 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
 	unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
 
 	fs_info->workers =
-		btrfs_alloc_workqueue("worker", flags | WQ_HIGHPRI,
-				      max_active, 16);
+		btrfs_alloc_workqueue(fs_info, "worker",
+				      flags | WQ_HIGHPRI, max_active, 16);
 
 	fs_info->delalloc_workers =
-		btrfs_alloc_workqueue("delalloc", flags, max_active, 2);
+		btrfs_alloc_workqueue(fs_info, "delalloc",
+				      flags, max_active, 2);
 
 	fs_info->flush_workers =
-		btrfs_alloc_workqueue("flush_delalloc", flags, max_active, 0);
+		btrfs_alloc_workqueue(fs_info, "flush_delalloc",
+				      flags, max_active, 0);
 
 	fs_info->caching_workers =
-		btrfs_alloc_workqueue("cache", flags, max_active, 0);
+		btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
 
 	/*
 	 * a higher idle thresh on the submit workers makes it much more
@@ -2328,41 +2330,48 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
 	 * devices
 	 */
 	fs_info->submit_workers =
-		btrfs_alloc_workqueue("submit", flags,
+		btrfs_alloc_workqueue(fs_info, "submit", flags,
 				      min_t(u64, fs_devices->num_devices,
 					    max_active), 64);
 
 	fs_info->fixup_workers =
-		btrfs_alloc_workqueue("fixup", flags, 1, 0);
+		btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
 
 	/*
 	 * endios are largely parallel and should have a very
 	 * low idle thresh
 	 */
 	fs_info->endio_workers =
-		btrfs_alloc_workqueue("endio", flags, max_active, 4);
+		btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
 	fs_info->endio_meta_workers =
-		btrfs_alloc_workqueue("endio-meta", flags, max_active, 4);
+		btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
+				      max_active, 4);
 	fs_info->endio_meta_write_workers =
-		btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);
+		btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
+				      max_active, 2);
 	fs_info->endio_raid56_workers =
-		btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);
+		btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
+				      max_active, 4);
 	fs_info->endio_repair_workers =
-		btrfs_alloc_workqueue("endio-repair", flags, 1, 0);
+		btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
 	fs_info->rmw_workers =
-		btrfs_alloc_workqueue("rmw", flags, max_active, 2);
+		btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
 	fs_info->endio_write_workers =
-		btrfs_alloc_workqueue("endio-write", flags, max_active, 2);
+		btrfs_alloc_workqueue(fs_info, "endio-write", flags,
+				      max_active, 2);
 	fs_info->endio_freespace_worker =
-		btrfs_alloc_workqueue("freespace-write", flags, max_active, 0);
+		btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
+				      max_active, 0);
 	fs_info->delayed_workers =
-		btrfs_alloc_workqueue("delayed-meta", flags, max_active, 0);
+		btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
+				      max_active, 0);
 	fs_info->readahead_workers =
-		btrfs_alloc_workqueue("readahead", flags, max_active, 2);
+		btrfs_alloc_workqueue(fs_info, "readahead", flags,
+				      max_active, 2);
 	fs_info->qgroup_rescan_workers =
-		btrfs_alloc_workqueue("qgroup-rescan", flags, 1, 0);
+		btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
 	fs_info->extent_workers =
-		btrfs_alloc_workqueue("extent-refs", flags,
+		btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
 				      min_t(u64, fs_devices->num_devices,
 					    max_active), 8);
 

fs/btrfs/scrub.c

@@ -3781,27 +3781,27 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
 	if (fs_info->scrub_workers_refcnt == 0) {
 		if (is_dev_replace)
 			fs_info->scrub_workers =
-				btrfs_alloc_workqueue("scrub", flags,
+				btrfs_alloc_workqueue(fs_info, "scrub", flags,
 						      1, 4);
 		else
 			fs_info->scrub_workers =
-				btrfs_alloc_workqueue("scrub", flags,
+				btrfs_alloc_workqueue(fs_info, "scrub", flags,
 						      max_active, 4);
 		if (!fs_info->scrub_workers)
 			goto fail_scrub_workers;
 
 		fs_info->scrub_wr_completion_workers =
-			btrfs_alloc_workqueue("scrubwrc", flags,
+			btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
 					      max_active, 2);
 		if (!fs_info->scrub_wr_completion_workers)
 			goto fail_scrub_wr_completion_workers;
 
 		fs_info->scrub_nocow_workers =
-			btrfs_alloc_workqueue("scrubnc", flags, 1, 0);
+			btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0);
 		if (!fs_info->scrub_nocow_workers)
 			goto fail_scrub_nocow_workers;
 		fs_info->scrub_parity_workers =
-			btrfs_alloc_workqueue("scrubparity", flags,
+			btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
 					      max_active, 2);
 		if (!fs_info->scrub_parity_workers)
 			goto fail_scrub_parity_workers;