shmem: factor out sbi->free_inodes manipulations

The shmem_sb_info structure has a number of free_inodes. This
value is altered in appropriate places under spinlock and with
the sbi->max_inodes != 0 check.

Consolidate these manipulations into two helpers.

This is minus 42 bytes of shmem.o and minus 4 :) lines of code.

[akpm@linux-foundation.org: fix error return values]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/shmem.c b/mm/shmem.c
index 5dfe790..ce64b66 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -205,6 +205,31 @@ static void shmem_free_blocks(struct inode *inode, long pages)
        }
 }
 
+static int shmem_reserve_inode(struct super_block *sb)
+{
+       struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+       if (sbinfo->max_inodes) {
+               spin_lock(&sbinfo->stat_lock);
+               if (!sbinfo->free_inodes) {
+                       spin_unlock(&sbinfo->stat_lock);
+                       return -ENOSPC;
+               }
+               sbinfo->free_inodes--;
+               spin_unlock(&sbinfo->stat_lock);
+       }
+       return 0;
+}
+
+static void shmem_free_inode(struct super_block *sb)
+{
+       struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+       if (sbinfo->max_inodes) {
+               spin_lock(&sbinfo->stat_lock);
+               sbinfo->free_inodes++;
+               spin_unlock(&sbinfo->stat_lock);
+       }
+}
+
 /*
  * shmem_recalc_inode - recalculate the size of an inode
  *
@@ -762,7 +787,6 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 
 static void shmem_delete_inode(struct inode *inode)
 {
-       struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
        struct shmem_inode_info *info = SHMEM_I(inode);
 
        if (inode->i_op->truncate == shmem_truncate) {
@@ -777,11 +801,7 @@ static void shmem_delete_inode(struct inode *inode)
                }
        }
        BUG_ON(inode->i_blocks);
-       if (sbinfo->max_inodes) {
-               spin_lock(&sbinfo->stat_lock);
-               sbinfo->free_inodes++;
-               spin_unlock(&sbinfo->stat_lock);
-       }
+       shmem_free_inode(inode->i_sb);
        clear_inode(inode);
 }
 
@@ -1371,15 +1391,8 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
        struct shmem_inode_info *info;
        struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
 
-       if (sbinfo->max_inodes) {
-               spin_lock(&sbinfo->stat_lock);
-               if (!sbinfo->free_inodes) {
-                       spin_unlock(&sbinfo->stat_lock);
-                       return NULL;
-               }
-               sbinfo->free_inodes--;
-               spin_unlock(&sbinfo->stat_lock);
-       }
+       if (shmem_reserve_inode(sb))
+               return NULL;
 
        inode = new_inode(sb);
        if (inode) {
@@ -1423,11 +1436,8 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
                                                NULL);
                        break;
                }
-       } else if (sbinfo->max_inodes) {
-               spin_lock(&sbinfo->stat_lock);
-               sbinfo->free_inodes++;
-               spin_unlock(&sbinfo->stat_lock);
-       }
+       } else
+               shmem_free_inode(sb);
        return inode;
 }
 
@@ -1670,22 +1680,16 @@ static int shmem_create(struct inode *dir, struct dentry *dentry, int mode,
 static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 {
        struct inode *inode = old_dentry->d_inode;
-       struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+       int ret;
 
        /*
         * No ordinary (disk based) filesystem counts links as inodes;
         * but each new link needs a new dentry, pinning lowmem, and
         * tmpfs dentries cannot be pruned until they are unlinked.
         */
-       if (sbinfo->max_inodes) {
-               spin_lock(&sbinfo->stat_lock);
-               if (!sbinfo->free_inodes) {
-                       spin_unlock(&sbinfo->stat_lock);
-                       return -ENOSPC;
-               }
-               sbinfo->free_inodes--;
-               spin_unlock(&sbinfo->stat_lock);
-       }
+       ret = shmem_reserve_inode(inode->i_sb);
+       if (ret)
+               goto out;
 
        dir->i_size += BOGO_DIRENT_SIZE;
        inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
@@ -1693,21 +1697,16 @@ static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentr
        atomic_inc(&inode->i_count);    /* New dentry reference */
        dget(dentry);           /* Extra pinning count for the created dentry */
        d_instantiate(dentry, inode);
-       return 0;
+out:
+       return ret;
 }
 
 static int shmem_unlink(struct inode *dir, struct dentry *dentry)
 {
        struct inode *inode = dentry->d_inode;
 
-       if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) {
-               struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
-               if (sbinfo->max_inodes) {
-                       spin_lock(&sbinfo->stat_lock);
-                       sbinfo->free_inodes++;
-                       spin_unlock(&sbinfo->stat_lock);
-               }
-       }
+       if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode))
+               shmem_free_inode(inode->i_sb);
 
        dir->i_size -= BOGO_DIRENT_SIZE;
        inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;