ssize_t written_buffered;
        size_t prev_left = 0;
        loff_t endbyte;
-       ssize_t err;
+       ssize_t ret;
        unsigned int ilock_flags = 0;
        struct iomap_dio *dio;
 
                ilock_flags |= BTRFS_ILOCK_SHARED;
 
 relock:
-       err = btrfs_inode_lock(BTRFS_I(inode), ilock_flags);
-       if (err < 0)
-               return err;
+       ret = btrfs_inode_lock(BTRFS_I(inode), ilock_flags);
+       if (ret < 0)
+               return ret;
 
        /* Shared lock cannot be used with security bits set. */
        if ((ilock_flags & BTRFS_ILOCK_SHARED) && !IS_NOSEC(inode)) {
                goto relock;
        }
 
-       err = generic_write_checks(iocb, from);
-       if (err <= 0) {
+       ret = generic_write_checks(iocb, from);
+       if (ret <= 0) {
                btrfs_inode_unlock(BTRFS_I(inode), ilock_flags);
-               return err;
+               return ret;
        }
 
-       err = btrfs_write_check(iocb, from, err);
-       if (err < 0) {
+       ret = btrfs_write_check(iocb, from, ret);
+       if (ret < 0) {
                btrfs_inode_unlock(BTRFS_I(inode), ilock_flags);
                goto out;
        }
        btrfs_inode_unlock(BTRFS_I(inode), ilock_flags);
 
        if (IS_ERR_OR_NULL(dio))
-               err = PTR_ERR_OR_ZERO(dio);
+               ret = PTR_ERR_OR_ZERO(dio);
        else
-               err = iomap_dio_complete(dio);
+               ret = iomap_dio_complete(dio);
 
        /* No increment (+=) because iomap returns a cumulative value. */
-       if (err > 0)
-               written = err;
+       if (ret > 0)
+               written = ret;
 
-       if (iov_iter_count(from) > 0 && (err == -EFAULT || err > 0)) {
+       if (iov_iter_count(from) > 0 && (ret == -EFAULT || ret > 0)) {
                const size_t left = iov_iter_count(from);
                /*
                 * We have more data left to write. Try to fault in as many as
                 * to buffered IO in case we haven't made any progress.
                 */
                if (left == prev_left) {
-                       err = -ENOTBLK;
+                       ret = -ENOTBLK;
                } else {
                        fault_in_iov_iter_readable(from, left);
                        prev_left = left;
        }
 
        /*
-        * If 'err' is -ENOTBLK or we have not written all data, then it means
+        * If 'ret' is -ENOTBLK or we have not written all data, then it means
         * we must fallback to buffered IO.
         */
-       if ((err < 0 && err != -ENOTBLK) || !iov_iter_count(from))
+       if ((ret < 0 && ret != -ENOTBLK) || !iov_iter_count(from))
                goto out;
 
 buffered:
         * below, we will block when flushing and waiting for the IO.
         */
        if (iocb->ki_flags & IOCB_NOWAIT) {
-               err = -EAGAIN;
+               ret = -EAGAIN;
                goto out;
        }
 
        pos = iocb->ki_pos;
        written_buffered = btrfs_buffered_write(iocb, from);
        if (written_buffered < 0) {
-               err = written_buffered;
+               ret = written_buffered;
                goto out;
        }
        /*
         * able to read what was just written.
         */
        endbyte = pos + written_buffered - 1;
-       err = btrfs_fdatawrite_range(inode, pos, endbyte);
-       if (err)
+       ret = btrfs_fdatawrite_range(inode, pos, endbyte);
+       if (ret)
                goto out;
-       err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
-       if (err)
+       ret = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
+       if (ret)
                goto out;
        written += written_buffered;
        iocb->ki_pos = pos + written_buffered;
        invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
                                 endbyte >> PAGE_SHIFT);
 out:
-       return err < 0 ? err : written;
+       return ret < 0 ? ret : written;
 }
 
 static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from,