ubifs: Remove dead code from ubifs_get_link()

[karo-tx-linux.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index c22eaf162f95c1456563b31a8362da9e531c9185..2a6889b3585f068c73091d8895639b7e941d702a 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1154,6 +1154,17 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
                goto out;
        }
 
+       /*
+        * It is possible, particularly with mixed reads & writes to private
+        * mappings, that we have raced with a PMD fault that overlaps with
+        * the PTE we need to set up.  If so just return and the fault will be
+        * retried.
+        */
+       if (pmd_trans_huge(*vmf->pmd) || pmd_devmap(*vmf->pmd)) {
+               vmf_ret = VM_FAULT_NOPAGE;
+               goto unlock_entry;
+       }
+
        /*
         * Note that we don't bother to use iomap_apply here: DAX required
         * the file system block size to be equal the page size, which means
@@ -1397,6 +1408,18 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
        if (IS_ERR(entry))
                goto fallback;
 
+       /*
+        * It is possible, particularly with mixed reads & writes to private
+        * mappings, that we have raced with a PTE fault that overlaps with
+        * the PMD we need to set up.  If so just return and the fault will be
+        * retried.
+        */
+       if (!pmd_none(*vmf->pmd) && !pmd_trans_huge(*vmf->pmd) &&
+                       !pmd_devmap(*vmf->pmd)) {
+               result = 0;
+               goto unlock_entry;
+       }
+
        /*
         * Note that we don't use iomap_apply here.  We aren't doing I/O, only
         * setting up a mapping, so really we're using iomap_begin() as a way