[PATCH 2/8] ubifs: move checks and preparation into setflags()

[Sascha Hauer <s.hauer@pengutronix.de>]

setflags() can be reused for upcoming FS_IOC_FS[SG]ETXATTR ioctl support.
In preparation for that move the checks and preparation into that
function so we can reuse them as well.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 fs/ubifs/ioctl.c | 46 +++++++++++++++++++++++++++-------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
index 5dc5abca11c7..8230dba5fd74 100644
--- a/fs/ubifs/ioctl.c
+++ b/fs/ubifs/ioctl.c
@@ -95,18 +95,35 @@ static int ubifs2ioctl(int ubifs_flags)
 	return ioctl_flags;
 }
 
-static int setflags(struct inode *inode, int flags)
+static int setflags(struct file *file, int flags)
 {
 	int oldflags, err, release;
+	struct inode *inode = file_inode(file);
 	struct ubifs_inode *ui = ubifs_inode(inode);
 	struct ubifs_info *c = inode->i_sb->s_fs_info;
 	struct ubifs_budget_req req = { .dirtied_ino = 1,
 					.dirtied_ino_d = ui->data_len };
 
-	err = ubifs_budget_space(c, &req);
+	if (IS_RDONLY(inode))
+		return -EROFS;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	/*
+	 * Make sure the file-system is read-write and make sure it
+	 * will not become read-only while we are changing the flags.
+	 */
+	err = mnt_want_write_file(file);
 	if (err)
 		return err;
 
+	dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		goto out_drop;
+
 	mutex_lock(&ui->ui_mutex);
 	oldflags = ubifs2ioctl(ui->flags);
 	err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
@@ -124,12 +141,18 @@ static int setflags(struct inode *inode, int flags)
 		ubifs_release_budget(c, &req);
 	if (IS_SYNC(inode))
 		err = write_inode_now(inode, 1);
+
+	mnt_drop_write_file(file);
+
 	return err;
 
 out_unlock:
 	ubifs_err(c, "can't modify inode %lu attributes", inode->i_ino);
 	mutex_unlock(&ui->ui_mutex);
 	ubifs_release_budget(c, &req);
+out_drop:
+	mnt_drop_write_file(file);
+
 	return err;
 }
 
@@ -146,12 +169,6 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		return put_user(flags, (int __user *) arg);
 
 	case FS_IOC_SETFLAGS: {
-		if (IS_RDONLY(inode))
-			return -EROFS;
-
-		if (!inode_owner_or_capable(inode))
-			return -EACCES;
-
 		if (get_user(flags, (int __user *) arg))
 			return -EFAULT;
 
@@ -161,17 +178,8 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (!S_ISDIR(inode->i_mode))
 			flags &= ~FS_DIRSYNC_FL;
 
-		/*
-		 * Make sure the file-system is read-write and make sure it
-		 * will not become read-only while we are changing the flags.
-		 */
-		err = mnt_want_write_file(file);
-		if (err)
-			return err;
-		dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
-		err = setflags(inode, flags);
-		mnt_drop_write_file(file);
-		return err;
+
+		return setflags(file, flags);
 	}
 	case FS_IOC_SET_ENCRYPTION_POLICY: {
 		struct ubifs_info *c = inode->i_sb->s_fs_info;
-- 
2.25.0