fs: fix kernel_write prototype

Make the position an in/out argument like all the other read/write
helpers and and make the buf argument a void pointer.

Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

drivers/mtd/nand/nandsim.c

···
 	if (err)
 		return err;
 	noreclaim_flag = memalloc_noreclaim_save();
-	tx = kernel_write(file, buf, count, pos);
+	tx = kernel_write(file, buf, count, &pos);
 	memalloc_noreclaim_restore(noreclaim_flag);
 	put_pages(ns);
 	return tx;

drivers/target/target_core_alua.c

···
 	u32 md_buf_len)
 {
 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
+	loff_t pos = 0;
 	int ret;
 
 	if (IS_ERR(file)) {
 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
 		return -ENODEV;
 	}
-	ret = kernel_write(file, md_buf, md_buf_len, 0);
+	ret = kernel_write(file, md_buf, md_buf_len, &pos);
 	if (ret < 0)
 		pr_err("Error writing ALUA metadata file: %s\n", path);
 	fput(file);

drivers/target/target_core_file.c

···
 
 	for (prot = 0; prot < prot_length;) {
 		sector_t len = min_t(sector_t, bufsize, prot_length - prot);
-		ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
+		ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 
 		if (ret != len) {
 			pr_err("vfs_write to prot file failed: %zd\n", ret);

drivers/target/target_core_pr.c

···
 	char path[512];
 	u32 pr_aptpl_buf_len;
 	int ret;
+	loff_t pos = 0;
 
 	memset(path, 0, 512);
 
···
 
 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
 
-	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
+	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
 
 	if (ret < 0)
 		pr_debug("Error writing APTPL metadata file: %s\n", path);

fs/ecryptfs/read_write.c

···
 	lower_file = ecryptfs_inode_to_private(ecryptfs_inode)->lower_file;
 	if (!lower_file)
 		return -EIO;
-	rc = kernel_write(lower_file, data, size, offset);
+	rc = kernel_write(lower_file, data, size, &offset);
 	mark_inode_dirty_sync(ecryptfs_inode);
 	return rc;
 }

fs/read_write.c

···
 }
 EXPORT_SYMBOL(__kernel_write);
 
-ssize_t kernel_write(struct file *file, const char *buf, size_t count,
-			    loff_t pos)
+ssize_t kernel_write(struct file *file, const void *buf, size_t count,
+			    loff_t *pos)
 {
 	mm_segment_t old_fs;
 	ssize_t res;
···
 	old_fs = get_fs();
 	set_fs(get_ds());
 	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
+	res = vfs_write(file, (__force const char __user *)buf, count, pos);
 	set_fs(old_fs);
 
 	return res;

include/linux/fs.h

···
 extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
 				    enum kernel_read_file_id);
 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
-extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
+extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
 extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
 extern struct file * open_exec(const char *);
  

kernel/sysctl_binary.c

···
 		size_t length = newlen / sizeof(*vec);
 		char *str, *end;
 		int i;
+		loff_t pos = 0;
 
 		str = buffer;
 		end = str + BUFSZ;
···
 			str += scnprintf(str, end - str, "%lu\t", value);
 		}
 
-		result = kernel_write(file, buffer, str - buffer, 0);
+		result = kernel_write(file, buffer, str - buffer, &pos);
 		if (result < 0)
 			goto out_kfree;
 	}
···
 		size_t length = newlen / sizeof(*vec);
 		char *str, *end;
 		int i;
+		loff_t pos = 0;
 
 		str = buffer;
 		end = str + BUFSZ;
···
 			str += scnprintf(str, end - str, "%lu\t", value);
 		}
 
-		result = kernel_write(file, buffer, str - buffer, 0);
+		result = kernel_write(file, buffer, str - buffer, &pos);
 		if (result < 0)
 			goto out_kfree;
 	}
···
 		__le16 dnaddr;
 		char buf[15];
 		int len;
+		loff_t pos = 0;
 
 		result = -EINVAL;
 		if (newlen != sizeof(dnaddr))
···
 				le16_to_cpu(dnaddr) >> 10,
 				le16_to_cpu(dnaddr) & 0x3ff);
 
-		result = kernel_write(file, buf, len, 0);
+		result = kernel_write(file, buf, len, &pos);
 		if (result < 0)
 			goto out;
 	}

security/keys/big_key.c

···
 		 * File content is stored encrypted with randomly generated key.
 		 */
 		size_t enclen = ALIGN(datalen, crypto_skcipher_blocksize(big_key_skcipher));
+		loff_t pos = 0;
 
 		/* prepare aligned data to encrypt */
 		data = kmalloc(enclen, GFP_KERNEL);
···
 			goto err_enckey;
 		}
 
-		written = kernel_write(file, data, enclen, 0);
+		written = kernel_write(file, data, enclen, &pos);
 		if (written != enclen) {
 			ret = written;
 			if (written >= 0)