From 0911d0041c22922228ca52a977d7b0b0159fee4b Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 8 Feb 2017 14:30:53 -0800 Subject: mm: avoid returning VM_FAULT_RETRY from ->page_mkwrite handlers Some ->page_mkwrite handlers may return VM_FAULT_RETRY as its return code (GFS2 or Lustre can definitely do this). However VM_FAULT_RETRY from ->page_mkwrite is completely unhandled by the mm code and results in locking and writeably mapping the page which definitely is not what the caller wanted. Fix Lustre and block_page_mkwrite_ret() used by other filesystems (notably GFS2) to return VM_FAULT_NOPAGE instead which results in bailing out from the fault code, the CPU then retries the access, and we fault again effectively doing what the handler wanted. Link: http://lkml.kernel.org/r/20170203150729.15863-1-jack@suse.cz Signed-off-by: Jan Kara Reported-by: Al Viro Reviewed-by: Jinshan Xiong Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/staging/lustre/lustre/llite/llite_mmap.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/staging/lustre/lustre/llite/llite_mmap.c b/drivers/staging/lustre/lustre/llite/llite_mmap.c index ee01f20d8b11..9afa6bec3e6f 100644 --- a/drivers/staging/lustre/lustre/llite/llite_mmap.c +++ b/drivers/staging/lustre/lustre/llite/llite_mmap.c @@ -390,15 +390,13 @@ static int ll_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) result = VM_FAULT_LOCKED; break; case -ENODATA: + case -EAGAIN: case -EFAULT: result = VM_FAULT_NOPAGE; break; case -ENOMEM: result = VM_FAULT_OOM; break; - case -EAGAIN: - result = VM_FAULT_RETRY; - break; default: result = VM_FAULT_SIGBUS; break; -- cgit v1.2.3