[PATCH 6/6] btrfs: unify common code for the v1 and v2 versions of device remove

[Josef Bacik <josef@toxicpanda.com>]

These things share a lot of common code, v2 simply allows you to specify
devid.  Abstract out this common code and use the helper by both the v1
and v2 interfaces to save us some lines of code.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ioctl.c | 99 +++++++++++++++++++-----------------------------
 1 file changed, 38 insertions(+), 61 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fabbfdfa56f5..e3a7e8544609 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3200,15 +3200,14 @@ static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
 	return ret;
 }
 
-static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
+static long btrfs_do_device_removal(struct file *file, const char *path,
+				    u64 devid, bool cancel)
 {
 	struct inode *inode = file_inode(file);
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct btrfs_ioctl_vol_args_v2 *vol_args;
 	struct block_device *bdev = NULL;
 	fmode_t mode;
 	int ret;
-	bool cancel = false;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -3217,11 +3216,37 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 	if (ret)
 		return ret;
 
-	vol_args = memdup_user(arg, sizeof(*vol_args));
-	if (IS_ERR(vol_args)) {
-		ret = PTR_ERR(vol_args);
-		goto err_drop;
+	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
+					   cancel);
+	if (ret)
+		goto out;
+
+	/* Exclusive operation is now claimed */
+	ret = btrfs_rm_device(fs_info, path, devid, &bdev, &mode);
+	btrfs_exclop_finish(fs_info);
+
+	if (!ret) {
+		if (path)
+			btrfs_info(fs_info, "device deleted: %s", path);
+		else
+			btrfs_info(fs_info, "device deleted: id %llu", devid);
 	}
+out:
+	mnt_drop_write_file(file);
+	if (bdev)
+		blkdev_put(bdev, mode);
+	return ret;
+}
+
+static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
+{
+	struct btrfs_ioctl_vol_args_v2 *vol_args;
+	int ret = 0;
+	bool cancel = false;
+
+	vol_args = memdup_user(arg, sizeof(*vol_args));
+	if (IS_ERR(vol_args))
+		return PTR_ERR(vol_args);
 
 	if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
 		ret = -EOPNOTSUPP;
@@ -3232,79 +3257,31 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 	    strcmp("cancel", vol_args->name) == 0)
 		cancel = true;
 
-	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
-					   cancel);
-	if (ret)
-		goto out;
-	/* Exclusive operation is now claimed */
-
 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
-		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid, &bdev,
-				      &mode);
+		ret = btrfs_do_device_removal(file, NULL, vol_args->devid,
+					      cancel);
 	else
-		ret = btrfs_rm_device(fs_info, vol_args->name, 0, &bdev,
-				      &mode);
-
-	btrfs_exclop_finish(fs_info);
-
-	if (!ret) {
-		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
-			btrfs_info(fs_info, "device deleted: id %llu",
-					vol_args->devid);
-		else
-			btrfs_info(fs_info, "device deleted: %s",
-					vol_args->name);
-	}
+		ret = btrfs_do_device_removal(file, vol_args->name, 0, cancel);
 out:
 	kfree(vol_args);
-err_drop:
-	mnt_drop_write_file(file);
-	if (bdev)
-		blkdev_put(bdev, mode);
 	return ret;
 }
 
 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
 {
-	struct inode *inode = file_inode(file);
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_ioctl_vol_args *vol_args;
-	struct block_device *bdev = NULL;
-	fmode_t mode;
 	int ret;
 	bool cancel;
 
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	ret = mnt_want_write_file(file);
-	if (ret)
-		return ret;
-
 	vol_args = memdup_user(arg, sizeof(*vol_args));
-	if (IS_ERR(vol_args)) {
-		ret = PTR_ERR(vol_args);
-		goto out_drop_write;
-	}
+	if (IS_ERR(vol_args))
+		return PTR_ERR(vol_args);
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	cancel = (strcmp("cancel", vol_args->name) == 0);
 
-	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
-					   cancel);
-	if (ret == 0) {
-		ret = btrfs_rm_device(fs_info, vol_args->name, 0, &bdev,
-				      &mode);
-		if (!ret)
-			btrfs_info(fs_info, "disk deleted %s", vol_args->name);
-		btrfs_exclop_finish(fs_info);
-	}
+	ret = btrfs_do_device_removal(file, vol_args->name, 0, cancel);
 
 	kfree(vol_args);
-out_drop_write:
-	mnt_drop_write_file(file);
-
-	if (bdev)
-		blkdev_put(bdev, mode);
 	return ret;
 }
 
-- 
2.26.3