dax: remove DAX code from page_cache_tree_insert()

Now that we no longer insert struct page pointers in DAX radix trees we
can remove the special casing for DAX in page_cache_tree_insert().

This also allows us to make dax_wake_mapping_entry_waiter() local to
fs/dax.c, removing it from dax.h.

Link: http://lkml.kernel.org/r/20170724170616.25810-5-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 3 insertions, 14 deletions

diff --git a/fs/dax.c b/fs/dax.c
index ab67ae30ccbf..8f70e3b59b91 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -127,7 +127,7 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo
  * correct waitqueue where tasks might be waiting for that old 'entry' and
  * wake them.
  */
-void dax_wake_mapping_entry_waiter(struct address_space *mapping,
+static void dax_wake_mapping_entry_waiter(struct address_space *mapping,
                 pgoff_t index, void *entry, bool wake_all)
 {
         struct exceptional_entry_key key;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index b3518559f0da..319e0d997446 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -123,8 +123,6 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
 int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
                                       pgoff_t index);
-void dax_wake_mapping_entry_waiter(struct address_space *mapping,
-                pgoff_t index, void *entry, bool wake_all);
 
 #ifdef CONFIG_FS_DAX
 int __dax_zero_page_range(struct block_device *bdev,
diff --git a/mm/filemap.c b/mm/filemap.c
index 65b4b6e7f7bd..dad935769055 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -130,17 +130,8 @@ static int page_cache_tree_insert(struct address_space *mapping,
                         return -EEXIST;
 
                 mapping->nrexceptional--;
-                if (!dax_mapping(mapping)) {
-                        if (shadowp)
-                                *shadowp = p;
-                } else {
-                        /* DAX can replace empty locked entry with a hole */
-                        WARN_ON_ONCE(p !=
-                                dax_radix_locked_entry(0, RADIX_DAX_EMPTY));
-                        /* Wakeup waiters for exceptional entry lock */
-                        dax_wake_mapping_entry_waiter(mapping, page->index, p,
-                                                      true);
-                }
+                if (shadowp)
+                        *shadowp = p;
         }
         __radix_tree_replace(&mapping->page_tree, node, slot, page,
                              workingset_update_node, mapping);