[PATCH] mm: filemap: correct the comment about VM_FAULT_RETRY

[Yang Shi]

The commit 6b4c9f446981 ("filemap: drop the mmap_sem for all blocking
operations") changed when mmap_sem is dropped during filemap page fault
and when returning VM_FAULT_RETRY.

Correct the comment to reflect the change.

Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
---
 mm/filemap.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index d78f577..f0d6250 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2545,10 +2545,8 @@ static struct file *do_async_mmap_readahead(struct vm_fault *vmf,
  *
  * vma->vm_mm->mmap_sem must be held on entry.
  *
- * If our return value has VM_FAULT_RETRY set, it's because
- * lock_page_or_retry() returned 0.
- * The mmap_sem has usually been released in this case.
- * See __lock_page_or_retry() for the exception.
+ * If our return value has VM_FAULT_RETRY set, it's because the mmap_sem
+ * may be dropped before doing I/O or by lock_page_maybe_drop_mmap().
  *
  * If our return value does not have VM_FAULT_RETRY set, the mmap_sem
  * has not been released.
-- 
1.8.3.1