looks good to me. Reviewed-by: Jinshan Xiong <jinshan.xiong@xxxxxxxxx> > On Feb 3, 2017, at 7:07 AM, Jan Kara <jack@xxxxxxx> wrote: > > 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. > > CC: lustre-devel@xxxxxxxxxxxxxxxx > CC: cluster-devel@xxxxxxxxxx > Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- > drivers/staging/lustre/lustre/llite/llite_mmap.c | 4 +--- > include/linux/buffer_head.h | 4 +--- > 2 files changed, 2 insertions(+), 6 deletions(-) > > 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; > diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h > index d67ab83823ad..79591c3660cc 100644 > --- a/include/linux/buffer_head.h > +++ b/include/linux/buffer_head.h > @@ -243,12 +243,10 @@ static inline int block_page_mkwrite_return(int err) > { > if (err == 0) > return VM_FAULT_LOCKED; > - if (err == -EFAULT) > + if (err == -EFAULT || err == -EAGAIN) > return VM_FAULT_NOPAGE; > if (err == -ENOMEM) > return VM_FAULT_OOM; > - if (err == -EAGAIN) > - return VM_FAULT_RETRY; > /* -ENOSPC, -EDQUOT, -EIO ... */ > return VM_FAULT_SIGBUS; > } > -- > 2.10.2 > > _______________________________________________ > lustre-devel mailing list > lustre-devel@xxxxxxxxxxxxxxxx > http://lists.lustre.org/listinfo.cgi/lustre-devel-lustre.org -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href