1 files changed, 8 insertions, 4 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 04fb4f1ab88e..d38d7e61fcd0 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -50,14 +50,12 @@
 #include <linux/migrate.h>
 #include <linux/highmem.h>
 #include <linux/seq_file.h>
+#include <linux/magic.h>
 
 #include <asm/uaccess.h>
 #include <asm/div64.h>
 #include <asm/pgtable.h>
 
-/* This magic number is used in glibc for posix shared memory */
-#define TMPFS_MAGIC     0x01021994
-
 #define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long))
 #define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)
 #define BLOCKS_PER_PAGE  (PAGE_CACHE_SIZE/512)
@@ -201,7 +199,7 @@ static struct vm_operations_struct shmem_vm_ops;
 
 static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {
         .ra_pages       = 0,    /* No readahead */
-        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
+        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED,
         .unplug_io_fn   = default_unplug_io_fn,
 };
 
@@ -1369,6 +1367,7 @@ repeat:
                                 error = -ENOMEM;
                                 goto failed;
                         }
+                        SetPageSwapBacked(filepage);
 
                         /* Precharge page while we can wait, compensate after */
                         error = mem_cgroup_cache_charge(filepage, current->mm,
@@ -1478,12 +1477,16 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
                 if (!user_shm_lock(inode->i_size, user))
                         goto out_nomem;
                 info->flags |= VM_LOCKED;
+                mapping_set_unevictable(file->f_mapping);
         }
         if (!lock && (info->flags & VM_LOCKED) && user) {
                 user_shm_unlock(inode->i_size, user);
                 info->flags &= ~VM_LOCKED;
+                mapping_clear_unevictable(file->f_mapping);
+                scan_mapping_unevictable_pages(file->f_mapping);
         }
         retval = 0;
+
 out_nomem:
         spin_unlock(&info->lock);
         return retval;
@@ -2582,6 +2585,7 @@ put_memory:
         shmem_unacct_size(flags, size);
         return ERR_PTR(error);
 }
+EXPORT_SYMBOL_GPL(shmem_file_setup);
 
 /**
  * shmem_zero_setup - setup a shared anonymous mapping