export kernel_write(), convert open-coded instances

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

5 files changed, 24 insertions, 61 deletions

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 818b65c85d12..8f30d385bfa3 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/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;
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index b2a34a192f4f..6a160539cd23 100644
--- a/fs/ecryptfs/read_write.c
+++ b/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;
 }
diff --git a/fs/splice.c b/fs/splice.c
index 963213d56403..718bd0056384 100644
--- a/fs/splice.c
+++ b/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,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c766afd1e684..d858363a7c17 100644
--- a/include/linux/fs.h
+++ b/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 */
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 5a6384450501..37f240fec37a 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -971,7 +971,6 @@ out:
 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 @@ out:
 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 @@ out:
 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 @@ out:
 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;
         }