From: Jeff Moyer <jmoyer@redhat.com>
Date: Wed, 27 Jun 2018 11:43:58 -0400
Subject: dev-dax: check_vma: ratelimit dev_info-s
Git-commit: 5a14e91d559aee5bdb0e002e1153fd9c4338a29e
Patch-mainline: v4.18-rc5
References: FATE#326060

This is easily triggered from userspace, so let's ratelimit the
messages.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/dax/device.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index de2f8297a210..108c37fca782 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -189,14 +189,16 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 
 	/* prevent private mappings from being established */
 	if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
-		dev_info(dev, "%s: %s: fail, attempted private mapping\n",
+		dev_info_ratelimited(dev,
+				"%s: %s: fail, attempted private mapping\n",
 				current->comm, func);
 		return -EINVAL;
 	}
 
 	mask = dax_region->align - 1;
 	if (vma->vm_start & mask || vma->vm_end & mask) {
-		dev_info(dev, "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
+		dev_info_ratelimited(dev,
+				"%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
 				current->comm, func, vma->vm_start, vma->vm_end,
 				mask);
 		return -EINVAL;
@@ -204,13 +206,15 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 
 	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
 			&& (vma->vm_flags & VM_DONTCOPY) == 0) {
-		dev_info(dev, "%s: %s: fail, dax range requires MADV_DONTFORK\n",
+		dev_info_ratelimited(dev,
+				"%s: %s: fail, dax range requires MADV_DONTFORK\n",
 				current->comm, func);
 		return -EINVAL;
 	}
 
 	if (!vma_is_dax(vma)) {
-		dev_info(dev, "%s: %s: fail, vma is not DAX capable\n",
+		dev_info_ratelimited(dev,
+				"%s: %s: fail, vma is not DAX capable\n",
 				current->comm, func);
 		return -EINVAL;
 	}