Merge tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdim...

[mirror_ubuntu-artful-kernel.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index ce9dc9c3e829eef663d7f448ad1a6c7b0000a84c..43bbd6d1037d20099bc50393ab2b255f02e188a7 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -327,6 +327,22 @@ restart:
                }
                spin_lock_irq(&mapping->tree_lock);
 
+               if (!entry) {
+                       /*
+                        * We needed to drop the page_tree lock while calling
+                        * radix_tree_preload() and we didn't have an entry to
+                        * lock.  See if another thread inserted an entry at
+                        * our index during this time.
+                        */
+                       entry = __radix_tree_lookup(&mapping->page_tree, index,
+                                       NULL, &slot);
+                       if (entry) {
+                               radix_tree_preload_end();
+                               spin_unlock_irq(&mapping->tree_lock);
+                               goto restart;
+                       }
+               }
+
                if (pmd_downgrade) {
                        radix_tree_delete(&mapping->page_tree, index);
                        mapping->nrexceptional--;
@@ -342,19 +358,12 @@ restart:
                if (err) {
                        spin_unlock_irq(&mapping->tree_lock);
                        /*
-                        * Someone already created the entry?  This is a
-                        * normal failure when inserting PMDs in a range
-                        * that already contains PTEs.  In that case we want
-                        * to return -EEXIST immediately.
-                        */
-                       if (err == -EEXIST && !(size_flag & RADIX_DAX_PMD))
-                               goto restart;
-                       /*
-                        * Our insertion of a DAX PMD entry failed, most
-                        * likely because it collided with a PTE sized entry
-                        * at a different index in the PMD range.  We haven't
-                        * inserted anything into the radix tree and have no
-                        * waiters to wake.
+                        * Our insertion of a DAX entry failed, most likely
+                        * because we were inserting a PMD entry and it
+                        * collided with a PTE sized entry at a different
+                        * index in the PMD range.  We haven't inserted
+                        * anything into the radix tree and have no waiters to
+                        * wake.
                         */
                        return ERR_PTR(err);
                }
@@ -964,7 +973,7 @@ int __dax_zero_page_range(struct block_device *bdev,
                sector_t start_sector = sector + (offset >> 9);
 
                return blkdev_issue_zeroout(bdev, start_sector,
-                               size >> 9, GFP_NOFS, true);
+                               size >> 9, GFP_NOFS, 0);
        } else {
                pgoff_t pgoff;
                long rc, id;