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>

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index d19b30a..2040275 100644 (file)
--- 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;
 }
 

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 8c43cc4..f62c2f6 100644 (file)
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -6,6 +6,8 @@
 #include <linux/fs.h>
 #include <linux/hugetlb_inline.h>
 #include <linux/cgroup.h>
+#include <linux/list.h>
+#include <linux/kref.h>
 
 struct ctl_table;
 struct user_struct;
@@ -23,6 +25,13 @@ struct hugepage_subpool {
        long max_hpages, used_hpages;
 };
 
+struct resv_map {
+       struct kref refs;
+       struct list_head regions;
+};
+extern struct resv_map *resv_map_alloc(void);
+void resv_map_release(struct kref *ref);
+
 extern spinlock_t hugetlb_lock;
 extern int hugetlb_max_hstate __read_mostly;
 #define for_each_hstate(h) \

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 139b746..63699af 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -376,12 +376,7 @@ static void set_vma_private_data(struct vm_area_struct *vma,
        vma->vm_private_data = (void *)value;
 }
 
-struct resv_map {
-       struct kref refs;
-       struct list_head regions;
-};
-
-static struct resv_map *resv_map_alloc(void)
+struct resv_map *resv_map_alloc(void)
 {
        struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
        if (!resv_map)
@@ -393,7 +388,7 @@ static struct resv_map *resv_map_alloc(void)
        return resv_map;
 }
 
-static void resv_map_release(struct kref *ref)
+void resv_map_release(struct kref *ref)
 {
        struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
 
@@ -1155,8 +1150,9 @@ static long vma_needs_reservation(struct hstate *h,
 
        if (vma->vm_flags & VM_MAYSHARE) {
                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
-               return region_chg(&inode->i_mapping->private_list,
-                                                       idx, idx + 1);
+               struct resv_map *resv = inode->i_mapping->private_data;
+
+               return region_chg(&resv->regions, idx, idx + 1);
 
        } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
                return 1;
@@ -1180,7 +1176,9 @@ static void vma_commit_reservation(struct hstate *h,
 
        if (vma->vm_flags & VM_MAYSHARE) {
                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
-               region_add(&inode->i_mapping->private_list, idx, idx + 1);
+               struct resv_map *resv = inode->i_mapping->private_data;
+
+               region_add(&resv->regions, idx, idx + 1);
 
        } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
@@ -3161,6 +3159,7 @@ int hugetlb_reserve_pages(struct inode *inode,
        long ret, chg;
        struct hstate *h = hstate_inode(inode);
        struct hugepage_subpool *spool = subpool_inode(inode);
+       struct resv_map *resv_map;
 
        /*
         * Only apply hugepage reservation if asked. At fault time, an
@@ -3176,10 +3175,13 @@ int hugetlb_reserve_pages(struct inode *inode,
         * to reserve the full area even if read-only as mprotect() may be
         * called to make the mapping read-write. Assume !vma is a shm mapping
         */
-       if (!vma || vma->vm_flags & VM_MAYSHARE)
-               chg = region_chg(&inode->i_mapping->private_list, from, to);
-       else {
-               struct resv_map *resv_map = resv_map_alloc();
+       if (!vma || vma->vm_flags & VM_MAYSHARE) {
+               resv_map = inode->i_mapping->private_data;
+
+               chg = region_chg(&resv_map->regions, from, to);
+
+       } else {
+               resv_map = resv_map_alloc();
                if (!resv_map)
                        return -ENOMEM;
 
@@ -3222,7 +3224,7 @@ int hugetlb_reserve_pages(struct inode *inode,
         * else has to be done for private mappings here
         */
        if (!vma || vma->vm_flags & VM_MAYSHARE)
-               region_add(&inode->i_mapping->private_list, from, to);
+               region_add(&resv_map->regions, from, to);
        return 0;
 out_err:
        if (vma)
@@ -3233,9 +3235,12 @@ out_err:
 void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
 {
        struct hstate *h = hstate_inode(inode);
-       long chg = region_truncate(&inode->i_mapping->private_list, offset);
+       struct resv_map *resv_map = inode->i_mapping->private_data;
+       long chg = 0;
        struct hugepage_subpool *spool = subpool_inode(inode);
 
+       if (resv_map)
+               chg = region_truncate(&resv_map->regions, offset);
        spin_lock(&inode->i_lock);
        inode->i_blocks -= (blocks_per_huge_page(h) * freed);
        spin_unlock(&inode->i_lock);