3 files changed, 91 insertions, 1 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 7eb80d33c4f3..8e01c865586e 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1231,6 +1231,91 @@ err:
         return err;
 }
 
+static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
+                             struct fuse_copy_state *cs)
+{
+        struct fuse_notify_store_out outarg;
+        struct inode *inode;
+        struct address_space *mapping;
+        u64 nodeid;
+        int err;
+        pgoff_t index;
+        unsigned int offset;
+        unsigned int num;
+        loff_t file_size;
+        loff_t end;
+
+        err = -EINVAL;
+        if (size < sizeof(outarg))
+                goto out_finish;
+
+        err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+        if (err)
+                goto out_finish;
+
+        err = -EINVAL;
+        if (size - sizeof(outarg) != outarg.size)
+                goto out_finish;
+
+        nodeid = outarg.nodeid;
+
+        down_read(&fc->killsb);
+
+        err = -ENOENT;
+        if (!fc->sb)
+                goto out_up_killsb;
+
+        inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
+        if (!inode)
+                goto out_up_killsb;
+
+        mapping = inode->i_mapping;
+        index = outarg.offset >> PAGE_CACHE_SHIFT;
+        offset = outarg.offset & ~PAGE_CACHE_MASK;
+        file_size = i_size_read(inode);
+        end = outarg.offset + outarg.size;
+        if (end > file_size) {
+                file_size = end;
+                fuse_write_update_size(inode, file_size);
+        }
+
+        num = outarg.size;
+        while (num) {
+                struct page *page;
+                unsigned int this_num;
+
+                err = -ENOMEM;
+                page = find_or_create_page(mapping, index,
+                                           mapping_gfp_mask(mapping));
+                if (!page)
+                        goto out_iput;
+
+                this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
+                err = fuse_copy_page(cs, &page, offset, this_num, 0);
+                if (!err && offset == 0 && (num != 0 || file_size == end))
+                        SetPageUptodate(page);
+                unlock_page(page);
+                page_cache_release(page);
+
+                if (err)
+                        goto out_iput;
+
+                num -= this_num;
+                offset = 0;
+                index++;
+        }
+
+        err = 0;
+
+out_iput:
+        iput(inode);
+out_up_killsb:
+        up_read(&fc->killsb);
+out_finish:
+        fuse_copy_finish(cs);
+        return err;
+}
+
 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
                        unsigned int size, struct fuse_copy_state *cs)
 {
@@ -1244,6 +1329,9 @@ static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
         case FUSE_NOTIFY_INVAL_ENTRY:
                 return fuse_notify_inval_entry(fc, size, cs);
 
+        case FUSE_NOTIFY_STORE:
+                return fuse_notify_store(fc, size, cs);
+
         default:
                 fuse_copy_finish(cs);
                 return -EINVAL;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index ada0adeb3bb5..147c1f71bdb9 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -706,7 +706,7 @@ static int fuse_write_begin(struct file *file, struct address_space *mapping,
         return 0;
 }
 
-static void fuse_write_update_size(struct inode *inode, loff_t pos)
+void fuse_write_update_size(struct inode *inode, loff_t pos)
 {
         struct fuse_conn *fc = get_fuse_conn(inode);
         struct fuse_inode *fi = get_fuse_inode(inode);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 8f309f04064e..61267d8d527b 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -748,4 +748,6 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 int fuse_dev_release(struct inode *inode, struct file *file);
 
+void fuse_write_update_size(struct inode *inode, loff_t pos);
+
 #endif /* _FS_FUSE_I_H */