Merge tag 'upstream-3.5-rc2' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS fixes from Artem Bityutskiy:
 "Fix UBI and UBIFS - they refuse to work without debugfs.  This was
  broken by the 3.5-rc1 UBI/UBIFS changes when we removed the debugging
  Kconfig switches.

  Also, correct locking in 'ubi_wl_flush()' - it was extended to support
  flushing a specific LEB in 3.5-rc1, and the locking was sub-optimal."

* tag 'upstream-3.5-rc2' of git://git.infradead.org/linux-ubifs:
  UBI: correct ubi_wl_flush locking
  UBIFS: fix debugfs-less systems support
  UBI: fix debugfs-less systems support

drivers/mtd/ubi/debug.c

@@ -264,6 +264,9 @@ static struct dentry *dfs_rootdir;
  */
 int ubi_debugfs_init(void)
 {
+	if (!IS_ENABLED(DEBUG_FS))
+		return 0;
+
 	dfs_rootdir = debugfs_create_dir("ubi", NULL);
 	if (IS_ERR_OR_NULL(dfs_rootdir)) {
 		int err = dfs_rootdir ? -ENODEV : PTR_ERR(dfs_rootdir);
@@ -281,6 +284,7 @@ int ubi_debugfs_init(void)
  */
 void ubi_debugfs_exit(void)
 {
+	if (IS_ENABLED(DEBUG_FS))
 		debugfs_remove(dfs_rootdir);
 }
 
@@ -403,6 +407,9 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
 	struct dentry *dent;
 	struct ubi_debug_info *d = ubi->dbg;
 
+	if (!IS_ENABLED(DEBUG_FS))
+		return 0;
+
 	n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME,
 		     ubi->ubi_num);
 	if (n == UBI_DFS_DIR_LEN) {
@@ -470,5 +477,6 @@ out:
  */
 void ubi_debugfs_exit_dev(struct ubi_device *ubi)
 {
+	if (IS_ENABLED(DEBUG_FS))
 		debugfs_remove_recursive(ubi->dbg->dfs_dir);
 }

drivers/mtd/ubi/wl.c

@@ -1262,11 +1262,11 @@ int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum)
 	dbg_wl("flush pending work for LEB %d:%d (%d pending works)",
 	       vol_id, lnum, ubi->works_count);
 
-	down_write(&ubi->work_sem);
 	while (found) {
 		struct ubi_work *wrk;
 		found = 0;
 
+		down_read(&ubi->work_sem);
 		spin_lock(&ubi->wl_lock);
 		list_for_each_entry(wrk, &ubi->works, list) {
 			if ((vol_id == UBI_ALL || wrk->vol_id == vol_id) &&
@@ -1277,18 +1277,27 @@ int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum)
 				spin_unlock(&ubi->wl_lock);
 
 				err = wrk->func(ubi, wrk, 0);
-				if (err)
-					goto out;
+				if (err) {
+					up_read(&ubi->work_sem);
+					return err;
+				}
+
 				spin_lock(&ubi->wl_lock);
 				found = 1;
 				break;
 			}
 		}
 		spin_unlock(&ubi->wl_lock);
+		up_read(&ubi->work_sem);
 	}
 
-out:
+	/*
+	 * Make sure all the works which have been done in parallel are
+	 * finished.
+	 */
+	down_write(&ubi->work_sem);
 	up_write(&ubi->work_sem);
+
 	return err;
 }
 

fs/ubifs/debug.c

@@ -2918,6 +2918,9 @@ int dbg_debugfs_init_fs(struct ubifs_info *c)
 	struct dentry *dent;
 	struct ubifs_debug_info *d = c->dbg;
 
+	if (!IS_ENABLED(DEBUG_FS))
+		return 0;
+
 	n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,
 		     c->vi.ubi_num, c->vi.vol_id);
 	if (n == UBIFS_DFS_DIR_LEN) {
@@ -3010,6 +3013,7 @@ out:
  */
 void dbg_debugfs_exit_fs(struct ubifs_info *c)
 {
+	if (IS_ENABLED(DEBUG_FS))
 		debugfs_remove_recursive(c->dbg->dfs_dir);
 }
 
@@ -3095,6 +3099,9 @@ int dbg_debugfs_init(void)
 	const char *fname;
 	struct dentry *dent;
 
+	if (!IS_ENABLED(DEBUG_FS))
+		return 0;
+
 	fname = "ubifs";
 	dent = debugfs_create_dir(fname, NULL);
 	if (IS_ERR_OR_NULL(dent))
@@ -3159,6 +3166,7 @@ out:
  */
 void dbg_debugfs_exit(void)
 {
+	if (IS_ENABLED(DEBUG_FS))
 		debugfs_remove_recursive(dfs_rootdir);
 }