diff mbox series

[3/3] btrfs: simplify codeflow in btrfs_ioctl_balance

Message ID 20220330091407.1319454-4-nborisov@suse.com (mailing list archive)
State New, archived
Headers show
Series Remove balance v1 ioctl | expand

Commit Message

Nikolay Borisov March 30, 2022, 9:14 a.m. UTC 
Move code in btrfs_ioctl_balance to simplify its code flow. This is
possible thanks to the removal of balance v1 ioctl and ensuring 'arg'
argument is always present. First move the code duplicating the userspace
arg to the kernel 'barg'. This makes the out_unlock label redundant.
Secondly, check the validity of bargs::flags before copying to the
dynamically allocated 'bctl'. This removes the need for the out_bctl
label.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/ioctl.c | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 95e47e6f8d41..a5484a098b92 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4353,6 +4353,12 @@  static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 	if (ret)
 		return ret;
 
+	bargs = memdup_user(arg, sizeof(*bargs));
+	if (IS_ERR(bargs)) {
+		ret = PTR_ERR(bargs);
+		goto out;
+	}
+
 again:
 	if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
 		mutex_lock(&fs_info->balance_mutex);
@@ -4400,13 +4406,6 @@  static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 	}
 
 locked:
-
-	bargs = memdup_user(arg, sizeof(*bargs));
-	if (IS_ERR(bargs)) {
-		ret = PTR_ERR(bargs);
-		goto out_unlock;
-	}
-
 	if (bargs->flags & BTRFS_BALANCE_RESUME) {
 		if (!fs_info->balance_ctl) {
 			ret = -ENOTCONN;
@@ -4422,6 +4421,11 @@  static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 		goto do_balance;
 	}
 
+	if (bargs->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
+		ret = -EINVAL;
+		goto out_bargs;
+	}
+
 	if (fs_info->balance_ctl) {
 		ret = -EINPROGRESS;
 		goto out_bargs;
@@ -4438,12 +4442,6 @@  static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 	memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
 
 	bctl->flags = bargs->flags;
-
-	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
-		ret = -EINVAL;
-		goto out_bctl;
-	}
-
 do_balance:
 	/*
 	 * Ownership of bctl and exclusive operation goes to btrfs_balance.
@@ -4461,11 +4459,9 @@  static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 			ret = -EFAULT;
 	}
 
-out_bctl:
 	kfree(bctl);
 out_bargs:
 	kfree(bargs);
-out_unlock:
 	mutex_unlock(&fs_info->balance_mutex);
 	if (need_unlock)
 		btrfs_exclop_finish(fs_info);