+/*
+ * sync everything. Start out by waking pdflush, because that writes back
+ * all queues in parallel.
+ */
+static void do_sync(unsigned long wait)
+{
+ wakeup_pdflush(0);
+ sync_inodes(0); /* All mappings, inodes and their blockdevs */
+ DQUOT_SYNC(NULL);
+ sync_supers(); /* Write the superblocks */
+ sync_filesystems(0); /* Start syncing the filesystems */
+ sync_filesystems(wait); /* Waitingly sync the filesystems */
+ sync_inodes(wait); /* Mappings, inodes and blockdevs, again. */
+ if (!wait)
+ printk("Emergency Sync complete\n");
+ if (unlikely(laptop_mode))
+ laptop_sync_completion();
+}
+
+asmlinkage long sys_sync(void)
+{
+ do_sync(1);
+ return 0;
+}
+
+void emergency_sync(void)
+{
+ pdflush_operation(do_sync, 0);
+}
+
+/*
+ * Generic function to fsync a file.
+ *
+ * filp may be NULL if called via the msync of a vma.
+ */
+int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
+{
+ struct inode * inode = dentry->d_inode;
+ struct super_block * sb;
+ int ret, err;
+
+ /* sync the inode to buffers */
+ ret = write_inode_now(inode, 0);
+
+ /* sync the superblock to buffers */
+ sb = inode->i_sb;
+ lock_super(sb);
+ if (sb->s_op->write_super)
+ sb->s_op->write_super(sb);
+ unlock_super(sb);
+
+ /* .. finally sync the buffers to disk */
+ err = sync_blockdev(sb->s_bdev);
+ if (!ret)
+ ret = err;
+ return ret;
+}
+
+long do_fsync(struct file *file, int datasync)
+{
+ int ret;
+ int err;
+ struct address_space *mapping = file->f_mapping;
+
+ if (!file->f_op || !file->f_op->fsync) {
+ /* Why? We can still call filemap_fdatawrite */
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = filemap_fdatawrite(mapping);
+
+ /*
+ * We need to protect against concurrent writers, which could cause
+ * livelocks in fsync_buffers_list().
+ */
+ mutex_lock(&mapping->host->i_mutex);
+ err = file->f_op->fsync(file, file->f_path.dentry, datasync);
+ if (!ret)
+ ret = err;
+ mutex_unlock(&mapping->host->i_mutex);
+ err = filemap_fdatawait(mapping);
+ if (!ret)
+ ret = err;
+out:
+ return ret;
+}
+
+static long __do_fsync(unsigned int fd, int datasync)
+{
+ struct file *file;
+ int ret = -EBADF;
+
+ file = fget(fd);
+ if (file) {
+ ret = do_fsync(file, datasync);
+ fput(file);
+ }
+ return ret;
+}
+
+asmlinkage long sys_fsync(unsigned int fd)
+{
+ return __do_fsync(fd, 0);
+}
+
+asmlinkage long sys_fdatasync(unsigned int fd)
+{
+ return __do_fsync(fd, 1);
+}
+