cachefiles_write_page(): switch to __kernel_write()

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

2 files changed, 21 insertions, 29 deletions

diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index 25e745b8eb1b..616db0e77b44 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -880,7 +880,6 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
 {
         struct cachefiles_object *object;
         struct cachefiles_cache *cache;
-        mm_segment_t old_fs;
         struct file *file;
         struct path path;
         loff_t pos, eof;
@@ -914,36 +913,27 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
         if (IS_ERR(file)) {
                 ret = PTR_ERR(file);
         } else {
-                ret = -EIO;
-                if (file->f_op->write) {
-                        pos = (loff_t) page->index << PAGE_SHIFT;
-
-                        /* we mustn't write more data than we have, so we have
-                         * to beware of a partial page at EOF */
-                        eof = object->fscache.store_limit_l;
-                        len = PAGE_SIZE;
-                        if (eof & ~PAGE_MASK) {
-                                ASSERTCMP(pos, <, eof);
-                                if (eof - pos < PAGE_SIZE) {
-                                        _debug("cut short %llx to %llx",
-                                               pos, eof);
-                                        len = eof - pos;
-                                        ASSERTCMP(pos + len, ==, eof);
-                                }
+                pos = (loff_t) page->index << PAGE_SHIFT;
+
+                /* we mustn't write more data than we have, so we have
+                 * to beware of a partial page at EOF */
+                eof = object->fscache.store_limit_l;
+                len = PAGE_SIZE;
+                if (eof & ~PAGE_MASK) {
+                        ASSERTCMP(pos, <, eof);
+                        if (eof - pos < PAGE_SIZE) {
+                                _debug("cut short %llx to %llx",
+                                       pos, eof);
+                                len = eof - pos;
+                                ASSERTCMP(pos + len, ==, eof);
                         }
-
-                        data = kmap(page);
-                        file_start_write(file);
-                        old_fs = get_fs();
-                        set_fs(KERNEL_DS);
-                        ret = file->f_op->write(
-                                file, (const void __user *) data, len, &pos);
-                        set_fs(old_fs);
-                        kunmap(page);
-                        file_end_write(file);
-                        if (ret != len)
-                                ret = -EIO;
                 }
+
+                data = kmap(page);
+                ret = __kernel_write(file, data, len, &pos);
+                kunmap(page);
+                if (ret != len)
+                        ret = -EIO;
                 fput(file);
         }
 
diff --git a/fs/read_write.c b/fs/read_write.c
index 009d8542a889..7d9318c3d43c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -513,6 +513,8 @@ ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t
         return ret;
 }
 
+EXPORT_SYMBOL(__kernel_write);
+
 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
 {
         ssize_t ret;