diff options
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 7c76a123ba18..e9a0f330d33e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3150,6 +3150,14 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf) unsigned long vm_flags = vmf->vma->vm_flags; unsigned int mmap_miss; + /* + * If we have pre-content watches we need to disable readahead to make + * sure that we don't populate our mapping with 0 filled pages that we + * never emitted an event for. + */ + if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode))) + return fpin; + #ifdef CONFIG_TRANSPARENT_HUGEPAGE /* Use the readahead code, even if readahead is disabled */ if ((vm_flags & VM_HUGEPAGE) && HPAGE_PMD_ORDER <= MAX_PAGECACHE_ORDER) { @@ -3218,6 +3226,10 @@ static struct file *do_async_mmap_readahead(struct vm_fault *vmf, struct file *fpin = NULL; unsigned int mmap_miss; + /* See comment in do_sync_mmap_readahead. */ + if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode))) + return fpin; + /* If we don't want any read-ahead, don't bother */ if (vmf->vma->vm_flags & VM_RAND_READ || !ra->ra_pages) return fpin; |