* XXX: Huge page cache doesn't support writing yet. Drop all page
* cache for this file before processing writes.
*/
- if ((f->f_mode & FMODE_WRITE) && filemap_nr_thps(inode->i_mapping))
- truncate_pagecache(inode, 0);
+ if (f->f_mode & FMODE_WRITE) {
+ /*
+ * Paired with smp_mb() in collapse_file() to ensure nr_thps
+ * is up to date and the update to i_writecount by
+ * get_write_access() is visible. Ensures subsequent insertion
+ * of THPs into the page cache will fail.
+ */
+ smp_mb();
+ if (filemap_nr_thps(inode->i_mapping))
+ truncate_pagecache(inode, 0);
+ }
return 0;