+static int cifs_vmtruncate(struct inode * inode, loff_t offset)
+{
+ struct address_space *mapping = inode->i_mapping;
+ unsigned long limit;
+
+ spin_lock(&inode->i_lock);
+ if (inode->i_size < offset)
+ goto do_expand;
+ /*
+ * truncation of in-use swapfiles is disallowed - it would cause
+ * subsequent swapout to scribble on the now-freed blocks.
+ */
+ if (IS_SWAPFILE(inode)) {
+ spin_unlock(&inode->i_lock);
+ goto out_busy;
+ }
+ i_size_write(inode, offset);
+ spin_unlock(&inode->i_lock);
+ unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
+ truncate_inode_pages(mapping, offset);
+ goto out_truncate;
+
+do_expand:
+ limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+ if (limit != RLIM_INFINITY && offset > limit) {
+ spin_unlock(&inode->i_lock);
+ goto out_sig;
+ }
+ if (offset > inode->i_sb->s_maxbytes) {
+ spin_unlock(&inode->i_lock);
+ goto out_big;
+ }
+ i_size_write(inode, offset);
+ spin_unlock(&inode->i_lock);
+out_truncate:
+ if (inode->i_op && inode->i_op->truncate)
+ inode->i_op->truncate(inode);
+ return 0;
+out_sig:
+ send_sig(SIGXFSZ, current, 0);
+out_big:
+ return -EFBIG;
+out_busy:
+ return -ETXTBSY;
+}
+