mm, hugetlb: unify region structure handling

Currently, to track reserved and allocated regions, we use two different
ways, depending on the mapping.  For MAP_SHARED, we use
address_mapping's private_list and, while for MAP_PRIVATE, we use a
resv_map.

Now, we are preparing to change a coarse grained lock which protect a
region structure to fine grained lock, and this difference hinder it.
So, before changing it, unify region structure handling, consistently
using a resv_map regardless of the kind of mapping.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index d19b30ababf1..204027520937 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -366,7 +366,13 @@ static void truncate_hugepages(struct inode *inode, loff_t lstart)
 
 static void hugetlbfs_evict_inode(struct inode *inode)
 {
+        struct resv_map *resv_map;
+
         truncate_hugepages(inode, 0);
+        resv_map = (struct resv_map *)inode->i_mapping->private_data;
+        /* root inode doesn't have the resv_map, so we should check it */
+        if (resv_map)
+                resv_map_release(&resv_map->refs);
         clear_inode(inode);
 }
 
@@ -476,6 +482,11 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
                                         umode_t mode, dev_t dev)
 {
         struct inode *inode;
+        struct resv_map *resv_map;
+
+        resv_map = resv_map_alloc();
+        if (!resv_map)
+                return NULL;
 
         inode = new_inode(sb);
         if (inode) {
@@ -487,7 +498,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
                 inode->i_mapping->a_ops = &hugetlbfs_aops;
                 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-                INIT_LIST_HEAD(&inode->i_mapping->private_list);
+                inode->i_mapping->private_data = resv_map;
                 info = HUGETLBFS_I(inode);
                 /*
                  * The policy is initialized here even if we are creating a
@@ -517,7 +528,9 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
                         break;
                 }
                 lockdep_annotate_inode_mutex_key(inode);
-        }
+        } else
+                kref_put(&resv_map->refs, resv_map_release);
+
         return inode;
 }