export kernel_write(), convert open-coded instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/mtd/nand/nandsim.c

@@ -1408,40 +1408,32 @@ static void clear_memalloc(int memalloc)
 		current->flags &= ~PF_MEMALLOC;
 }
 
-static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
+static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
 {
-	mm_segment_t old_fs;
 	ssize_t tx;
 	int err, memalloc;
 
-	err = get_pages(ns, file, count, *pos);
+	err = get_pages(ns, file, count, pos);
 	if (err)
 		return err;
-	old_fs = get_fs();
-	set_fs(get_ds());
 	memalloc = set_memalloc();
-	tx = vfs_read(file, (char __user *)buf, count, pos);
+	tx = kernel_read(file, pos, buf, count);
 	clear_memalloc(memalloc);
-	set_fs(old_fs);
 	put_pages(ns);
 	return tx;
 }
 
-static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
+static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
 {
-	mm_segment_t old_fs;
 	ssize_t tx;
 	int err, memalloc;
 
-	err = get_pages(ns, file, count, *pos);
+	err = get_pages(ns, file, count, pos);
 	if (err)
 		return err;
-	old_fs = get_fs();
-	set_fs(get_ds());
 	memalloc = set_memalloc();
-	tx = vfs_write(file, (char __user *)buf, count, pos);
+	tx = kernel_write(file, buf, count, pos);
 	clear_memalloc(memalloc);
-	set_fs(old_fs);
 	put_pages(ns);
 	return tx;
 }
@@ -1511,7 +1503,7 @@ static void read_page(struct nandsim *ns, int num)
 			if (do_read_error(ns, num))
 				return;
 			pos = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
-			tx = read_file(ns, ns->cfile, ns->buf.byte, num, &pos);
+			tx = read_file(ns, ns->cfile, ns->buf.byte, num, pos);
 			if (tx != num) {
 				NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
 				return;
@@ -1573,7 +1565,7 @@ static int prog_page(struct nandsim *ns, int num)
 	u_char *pg_off;
 
 	if (ns->cfile) {
-		loff_t off, pos;
+		loff_t off;
 		ssize_t tx;
 		int all;
 
@@ -1585,8 +1577,7 @@ static int prog_page(struct nandsim *ns, int num)
 			memset(ns->file_buf, 0xff, ns->geom.pgszoob);
 		} else {
 			all = 0;
-			pos = off;
-			tx = read_file(ns, ns->cfile, pg_off, num, &pos);
+			tx = read_file(ns, ns->cfile, pg_off, num, off);
 			if (tx != num) {
 				NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
 				return -1;
@@ -1595,16 +1586,15 @@ static int prog_page(struct nandsim *ns, int num)
 		for (i = 0; i < num; i++)
 			pg_off[i] &= ns->buf.byte[i];
 		if (all) {
-			pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
-			tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, &pos);
+			loff_t pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
+			tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, pos);
 			if (tx != ns->geom.pgszoob) {
 				NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
 				return -1;
 			}
 			ns->pages_written[ns->regs.row] = 1;
 		} else {
-			pos = off;
-			tx = write_file(ns, ns->cfile, pg_off, num, &pos);
+			tx = write_file(ns, ns->cfile, pg_off, num, off);
 			if (tx != num) {
 				NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
 				return -1;

fs/ecryptfs/read_write.c

@@ -40,16 +40,12 @@ int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
 			 loff_t offset, size_t size)
 {
 	struct file *lower_file;
-	mm_segment_t fs_save;
 	ssize_t rc;
 
 	lower_file = ecryptfs_inode_to_private(ecryptfs_inode)->lower_file;
 	if (!lower_file)
 		return -EIO;
-	fs_save = get_fs();
-	set_fs(get_ds());
-	rc = vfs_write(lower_file, data, size, &offset);
-	set_fs(fs_save);
+	rc = kernel_write(lower_file, data, size, offset);
 	mark_inode_dirty_sync(ecryptfs_inode);
 	return rc;
 }

fs/splice.c

@@ -569,7 +569,7 @@ static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
 	return res;
 }
 
-static ssize_t kernel_write(struct file *file, const char *buf, size_t count,
+ssize_t kernel_write(struct file *file, const char *buf, size_t count,
 			    loff_t pos)
 {
 	mm_segment_t old_fs;
@@ -578,11 +578,12 @@ static ssize_t kernel_write(struct file *file, const char *buf, size_t count,
 	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, (const char __user *)buf, count, &pos);
+	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
 	set_fs(old_fs);
 
 	return res;
 }
+EXPORT_SYMBOL(kernel_write);
 
 ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 				 struct pipe_inode_info *pipe, size_t len,

include/linux/fs.h

@@ -2277,6 +2277,7 @@ static inline void i_readcount_inc(struct inode *inode)
 extern int do_pipe_flags(int *, int);
 
 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
+extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
 extern struct file * open_exec(const char *);
  
 /* fs/dcache.c -- generic fs support functions */

kernel/sysctl_binary.c

@@ -971,7 +971,6 @@ static ssize_t bin_string(struct file *file,
 static ssize_t bin_intvec(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t copied = 0;
 	char *buffer;
 	ssize_t result;
@@ -984,13 +983,10 @@ static ssize_t bin_intvec(struct file *file,
 	if (oldval && oldlen) {
 		unsigned __user *vec = oldval;
 		size_t length = oldlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buffer, BUFSZ - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buffer, BUFSZ - 1);
 		if (result < 0)
 			goto out_kfree;
 
@@ -1017,7 +1013,6 @@ static ssize_t bin_intvec(struct file *file,
 	if (newval && newlen) {
 		unsigned __user *vec = newval;
 		size_t length = newlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
@@ -1033,9 +1028,7 @@ static ssize_t bin_intvec(struct file *file,
 			str += snprintf(str, end - str, "%lu\t", value);
 		}
 
-		set_fs(KERNEL_DS);
-		result = vfs_write(file, buffer, str - buffer, &pos);
-		set_fs(old_fs);
+		result = kernel_write(file, buffer, str - buffer, 0);
 		if (result < 0)
 			goto out_kfree;
 	}
@@ -1049,7 +1042,6 @@ static ssize_t bin_intvec(struct file *file,
 static ssize_t bin_ulongvec(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t copied = 0;
 	char *buffer;
 	ssize_t result;
@@ -1062,13 +1054,10 @@ static ssize_t bin_ulongvec(struct file *file,
 	if (oldval && oldlen) {
 		unsigned long __user *vec = oldval;
 		size_t length = oldlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buffer, BUFSZ - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buffer, BUFSZ - 1);
 		if (result < 0)
 			goto out_kfree;
 
@@ -1095,7 +1084,6 @@ static ssize_t bin_ulongvec(struct file *file,
 	if (newval && newlen) {
 		unsigned long __user *vec = newval;
 		size_t length = newlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
@@ -1111,9 +1099,7 @@ static ssize_t bin_ulongvec(struct file *file,
 			str += snprintf(str, end - str, "%lu\t", value);
 		}
 
-		set_fs(KERNEL_DS);
-		result = vfs_write(file, buffer, str - buffer, &pos);
-		set_fs(old_fs);
+		result = kernel_write(file, buffer, str - buffer, 0);
 		if (result < 0)
 			goto out_kfree;
 	}
@@ -1127,19 +1113,15 @@ static ssize_t bin_ulongvec(struct file *file,
 static ssize_t bin_uuid(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t result, copied = 0;
 
 	/* Only supports reads */
 	if (oldval && oldlen) {
-		loff_t pos = 0;
 		char buf[40], *str = buf;
 		unsigned char uuid[16];
 		int i;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buf, sizeof(buf) - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buf, sizeof(buf) - 1);
 		if (result < 0)
 			goto out;
 
@@ -1175,18 +1157,14 @@ static ssize_t bin_uuid(struct file *file,
 static ssize_t bin_dn_node_address(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t result, copied = 0;
 
 	if (oldval && oldlen) {
-		loff_t pos = 0;
 		char buf[15], *nodep;
 		unsigned long area, node;
 		__le16 dnaddr;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buf, sizeof(buf) - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buf, sizeof(buf) - 1);
 		if (result < 0)
 			goto out;
 
@@ -1215,7 +1193,6 @@ static ssize_t bin_dn_node_address(struct file *file,
 	}
 
 	if (newval && newlen) {
-		loff_t pos = 0;
 		__le16 dnaddr;
 		char buf[15];
 		int len;
@@ -1232,9 +1209,7 @@ static ssize_t bin_dn_node_address(struct file *file,
 				le16_to_cpu(dnaddr) >> 10,
 				le16_to_cpu(dnaddr) & 0x3ff);
 
-		set_fs(KERNEL_DS);
-		result = vfs_write(file, buf, len, &pos);
-		set_fs(old_fs);
+		result = kernel_write(file, buf, len, 0);
 		if (result < 0)
 			goto out;
 	}