[PATCH] hugetlbfs: move free_inodes accounting

Move hugetlbfs accounting into ->alloc_inode / ->destroy_inode.  This keeps
the code simpler, fixes a loeak where a failing inode allocation wouldn't
decrement the counter and moves hugetlbfs_delete_inode and
hugetlbfs_forget_inode closer to their generic counterparts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 42 insertions, 36 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index a826a8add5e3..8e9d43633365 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -224,8 +224,6 @@ static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
 
 static void hugetlbfs_delete_inode(struct inode *inode)
 {
-        struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(inode->i_sb);
-
         hlist_del_init(&inode->i_hash);
         list_del_init(&inode->i_list);
         list_del_init(&inode->i_sb_list);
@@ -238,12 +236,6 @@ static void hugetlbfs_delete_inode(struct inode *inode)
 
         security_inode_delete(inode);
 
-        if (sbinfo->free_inodes >= 0) {
-                spin_lock(&sbinfo->stat_lock);
-                sbinfo->free_inodes++;
-                spin_unlock(&sbinfo->stat_lock);
-        }
-
         clear_inode(inode);
         destroy_inode(inode);
 }
@@ -251,7 +243,6 @@ static void hugetlbfs_delete_inode(struct inode *inode)
 static void hugetlbfs_forget_inode(struct inode *inode)
 {
         struct super_block *super_block = inode->i_sb;
-        struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(super_block);
 
         if (hlist_unhashed(&inode->i_hash))
                 goto out_truncate;
@@ -278,12 +269,6 @@ out_truncate:
         if (inode->i_data.nrpages)
                 truncate_hugepages(&inode->i_data, 0);
 
-        if (sbinfo->free_inodes >= 0) {
-                spin_lock(&sbinfo->stat_lock);
-                sbinfo->free_inodes++;
-                spin_unlock(&sbinfo->stat_lock);
-        }
-
         clear_inode(inode);
         destroy_inode(inode);
 }
@@ -375,17 +360,6 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
                                         gid_t gid, int mode, dev_t dev)
 {
         struct inode *inode;
-        struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
-
-        if (sbinfo->free_inodes >= 0) {
-                spin_lock(&sbinfo->stat_lock);
-                if (!sbinfo->free_inodes) {
-                        spin_unlock(&sbinfo->stat_lock);
-                        return NULL;
-                }
-                sbinfo->free_inodes--;
-                spin_unlock(&sbinfo->stat_lock);
-        }
 
         inode = new_inode(sb);
         if (inode) {
@@ -527,29 +501,51 @@ static void hugetlbfs_put_super(struct super_block *sb)
         }
 }
 
+static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
+{
+        if (sbinfo->free_inodes >= 0) {
+                spin_lock(&sbinfo->stat_lock);
+                if (unlikely(!sbinfo->free_inodes)) {
+                        spin_unlock(&sbinfo->stat_lock);
+                        return 0;
+                }
+                sbinfo->free_inodes--;
+                spin_unlock(&sbinfo->stat_lock);
+        }
+
+        return 1;
+}
+
+static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
+{
+        if (sbinfo->free_inodes >= 0) {
+                spin_lock(&sbinfo->stat_lock);
+                sbinfo->free_inodes++;
+                spin_unlock(&sbinfo->stat_lock);
+        }
+}
+
+
 static kmem_cache_t *hugetlbfs_inode_cachep;
 
 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 {
+        struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
         struct hugetlbfs_inode_info *p;
 
+        if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
+                return NULL;
         p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL);
-        if (!p)
+        if (unlikely(!p)) {
+                hugetlbfs_inc_free_inodes(sbinfo);
                 return NULL;
+        }
         return &p->vfs_inode;
 }
 
-static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
-{
-        struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
-
-        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
-            SLAB_CTOR_CONSTRUCTOR)
-                inode_init_once(&ei->vfs_inode);
-}
-
 static void hugetlbfs_destroy_inode(struct inode *inode)
 {
+        hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
         mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
         kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
 }
@@ -561,6 +557,16 @@ static struct address_space_operations hugetlbfs_aops = {
         .set_page_dirty = hugetlbfs_set_page_dirty,
 };
 
+
+static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
+{
+        struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
+
+        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+            SLAB_CTOR_CONSTRUCTOR)
+                inode_init_once(&ei->vfs_inode);
+}
+
 struct file_operations hugetlbfs_file_operations = {
         .mmap                   = hugetlbfs_file_mmap,
         .fsync                  = simple_sync_file,