/* Read-only file mappings need to be aligned for THP to work. */
if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && vma->vm_file &&
- (vm_flags & VM_DENYWRITE)) {
+ !inode_is_open_for_write(vma->vm_file->f_inode) &&
+ (vm_flags & VM_EXEC)) {
return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
HPAGE_PMD_NR);
}
else {
__mod_lruvec_page_state(new_page, NR_FILE_THPS, nr);
filemap_nr_thps_inc(mapping);
+ /*
+ * Paired with smp_mb() in do_dentry_open() to ensure
+ * i_writecount is up to date and the update to nr_thps is
+ * visible. Ensures the page cache will be truncated if the
+ * file is opened writable.
+ */
+ smp_mb();
+ if (inode_is_open_for_write(mapping->host)) {
+ result = SCAN_FAIL;
+ __mod_lruvec_page_state(new_page, NR_FILE_THPS, -nr);
+ filemap_nr_thps_dec(mapping);
+ goto xa_locked;
+ }
}
if (nr_none) {