diff options
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d97b20fad6e8..b0412be08fa2 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -457,7 +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); } @@ -1862,6 +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) { |