[PATCH 3/3] btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly

[Nikolay Borisov <nborisov@suse.com>]

Instead of returning an error value and using one of the parameters for
returning the actual object we are interested in just refactor the
function to directly return btrfs_device *. Also bubble up the error
handling for the special BTRFS_ERROR_DEV_MISSING_NOT_FOUND value into
btrfs_rm_device. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/dev-replace.c |  8 ++++----
 fs/btrfs/volumes.c     | 40 +++++++++++++++++++---------------------
 fs/btrfs/volumes.h     |  6 +++---
 3 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index dec01970d8c5..4e2b67d06305 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -409,10 +409,10 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
 	struct btrfs_device *tgt_device = NULL;
 	struct btrfs_device *src_device = NULL;
 
-	ret = btrfs_find_device_by_devspec(fs_info, srcdevid,
-					    srcdev_name, &src_device);
-	if (ret)
-		return ret;
+	src_device = btrfs_find_device_by_devspec(fs_info, srcdevid,
+						  srcdev_name);
+	if (IS_ERR(src_device))
+		return PTR_ERR(src_device);
 
 	ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
 					    src_device, &tgt_device);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6202aa15d0d7..ce336b39fa0f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1877,10 +1877,16 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 	if (ret)
 		goto out;
 
-	ret = btrfs_find_device_by_devspec(fs_info, devid, device_path,
-					   &device);
-	if (ret)
+	device = btrfs_find_device_by_devspec(fs_info, devid, device_path);
+
+	if (IS_ERR(device)) {
+		if (PTR_ERR(device) == -ENOENT &&
+		    strcmp(device_path, "missing") == 0)
+			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
+		else
+			ret = PTR_ERR(device);
 		goto out;
+	}
 
 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
 		ret = BTRFS_ERROR_DEV_TGT_REPLACE;
@@ -2153,30 +2159,22 @@ btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
 /*
  * Lookup a device given by device id, or the path if the id is 0.
  */
-int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
-				 const char *devpath,
-				 struct btrfs_device **device)
+struct btrfs_device *
+btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
+			     const char *devpath)
 {
-	int ret = 0;
+	struct btrfs_device *device;
 
 	if (devid) {
-		*device = btrfs_find_device(fs_info, devid, NULL, NULL);
-		if (!*device)
-			ret = -ENOENT;
+		device = btrfs_find_device(fs_info, devid, NULL, NULL);
+		if (!device)
+			return ERR_PTR(-ENOENT);
 	} else {
 		if (!devpath || !devpath[0])
-			return -EINVAL;
-
-		*device = btrfs_find_device_missing_or_by_path(fs_info, devpath);
-		if (IS_ERR(*device)) {
-			if (PTR_ERR(*device) == -ENOENT &&
-			    strcmp(devpath, "missing") == 0)
-				ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
-			else
-				ret = PTR_ERR(*device);
-		}
+			return ERR_PTR(-EINVAL);
+		device = btrfs_find_device_missing_or_by_path(fs_info, devpath);
 	}
-	return ret;
+	return device;
 }
 
 /*
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index e7811473024d..aefce895e994 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -410,9 +410,9 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
 void btrfs_assign_next_active_device(struct btrfs_device *device,
 				     struct btrfs_device *this_dev);
-int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
-					 const char *devpath,
-					 struct btrfs_device **device);
+struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
+						  u64 devid,
+						  const char *devpath);
 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 					const u64 *devid,
 					const u8 *uuid);
-- 
2.17.1