X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=mm%2Fkhugepaged.c;h=b0412be08fa2c5cbb0a21057b30b1351bbf7b820;hb=6c7a00b843370feaf7710cef2350367c7e61cd1a;hp=6c0185fdd81581dc51bb0c2fbd2f5ab7e5e0582f;hpb=e563592c3e4296780e5a184a917b8b86e126f0b3;p=linux-block.git

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 6c0185fdd815..b0412be08fa2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -442,9 +442,7 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
 static bool hugepage_vma_check(struct vm_area_struct *vma,
 			       unsigned long vm_flags)
 {
-	/* Explicitly disabled through madvise. */
-	if ((vm_flags & VM_NOHUGEPAGE) ||
-	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+	if (!transhuge_vma_enabled(vma, vm_flags))
 		return false;
 
 	/* Enabled via shmem mount options or sysfs settings. */
@@ -459,7 +457,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma,
 
 	/* 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);
 	}
@@ -1864,6 +1863,19 @@ out_unlock:
 	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) {