mm: Remove slab destructors from kmem_cache_create().
[linux-2.6-block.git] / fs / proc / inode.c
index d5ce65c68d7b2b538a87c0a58de0863941db6ff3..94e2c1adf184f157413fe9d91def4a0e447850ea 100644 (file)
@@ -10,6 +10,7 @@
 #include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/stat.h>
+#include <linux/completion.h>
 #include <linux/file.h>
 #include <linux/limits.h>
 #include <linux/init.h>
@@ -111,14 +112,14 @@ static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flag
 
        inode_init_once(&ei->vfs_inode);
 }
+
 int __init proc_init_inodecache(void)
 {
        proc_inode_cachep = kmem_cache_create("proc_inode_cache",
                                             sizeof(struct proc_inode),
                                             0, (SLAB_RECLAIM_ACCOUNT|
                                                SLAB_MEM_SPREAD),
-                                            init_once, NULL);
+                                            init_once);
        if (proc_inode_cachep == NULL)
                return -ENOMEM;
        return 0;
@@ -140,6 +141,251 @@ static const struct super_operations proc_sops = {
        .remount_fs     = proc_remount,
 };
 
+static void pde_users_dec(struct proc_dir_entry *pde)
+{
+       spin_lock(&pde->pde_unload_lock);
+       pde->pde_users--;
+       if (pde->pde_unload_completion && pde->pde_users == 0)
+               complete(pde->pde_unload_completion);
+       spin_unlock(&pde->pde_unload_lock);
+}
+
+static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       loff_t rv = -EINVAL;
+       loff_t (*llseek)(struct file *, loff_t, int);
+
+       spin_lock(&pde->pde_unload_lock);
+       /*
+        * remove_proc_entry() is going to delete PDE (as part of module
+        * cleanup sequence). No new callers into module allowed.
+        */
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       /*
+        * Bump refcount so that remove_proc_entry will wail for ->llseek to
+        * complete.
+        */
+       pde->pde_users++;
+       /*
+        * Save function pointer under lock, to protect against ->proc_fops
+        * NULL'ifying right after ->pde_unload_lock is dropped.
+        */
+       llseek = pde->proc_fops->llseek;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (!llseek)
+               llseek = default_llseek;
+       rv = llseek(file, offset, whence);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       ssize_t rv = -EIO;
+       ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       read = pde->proc_fops->read;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (read)
+               rv = read(file, buf, count, ppos);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       ssize_t rv = -EIO;
+       ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       write = pde->proc_fops->write;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (write)
+               rv = write(file, buf, count, ppos);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       unsigned int rv = 0;
+       unsigned int (*poll)(struct file *, struct poll_table_struct *);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       poll = pde->proc_fops->poll;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (poll)
+               rv = poll(file, pts);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       long rv = -ENOTTY;
+       long (*unlocked_ioctl)(struct file *, unsigned int, unsigned long);
+       int (*ioctl)(struct inode *, struct file *, unsigned int, unsigned long);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       unlocked_ioctl = pde->proc_fops->unlocked_ioctl;
+       ioctl = pde->proc_fops->ioctl;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (unlocked_ioctl) {
+               rv = unlocked_ioctl(file, cmd, arg);
+               if (rv == -ENOIOCTLCMD)
+                       rv = -EINVAL;
+       } else if (ioctl) {
+               lock_kernel();
+               rv = ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
+               unlock_kernel();
+       }
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+#ifdef CONFIG_COMPAT
+static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       long rv = -ENOTTY;
+       long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       compat_ioctl = pde->proc_fops->compat_ioctl;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (compat_ioctl)
+               rv = compat_ioctl(file, cmd, arg);
+
+       pde_users_dec(pde);
+       return rv;
+}
+#endif
+
+static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
+{
+       struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+       int rv = -EIO;
+       int (*mmap)(struct file *, struct vm_area_struct *);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       mmap = pde->proc_fops->mmap;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (mmap)
+               rv = mmap(file, vma);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static int proc_reg_open(struct inode *inode, struct file *file)
+{
+       struct proc_dir_entry *pde = PDE(inode);
+       int rv = 0;
+       int (*open)(struct inode *, struct file *);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       open = pde->proc_fops->open;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (open)
+               rv = open(inode, file);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static int proc_reg_release(struct inode *inode, struct file *file)
+{
+       struct proc_dir_entry *pde = PDE(inode);
+       int rv = 0;
+       int (*release)(struct inode *, struct file *);
+
+       spin_lock(&pde->pde_unload_lock);
+       if (!pde->proc_fops) {
+               spin_unlock(&pde->pde_unload_lock);
+               return rv;
+       }
+       pde->pde_users++;
+       release = pde->proc_fops->release;
+       spin_unlock(&pde->pde_unload_lock);
+
+       if (release)
+               rv = release(inode, file);
+
+       pde_users_dec(pde);
+       return rv;
+}
+
+static const struct file_operations proc_reg_file_ops = {
+       .llseek         = proc_reg_llseek,
+       .read           = proc_reg_read,
+       .write          = proc_reg_write,
+       .poll           = proc_reg_poll,
+       .unlocked_ioctl = proc_reg_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = proc_reg_compat_ioctl,
+#endif
+       .mmap           = proc_reg_mmap,
+       .open           = proc_reg_open,
+       .release        = proc_reg_release,
+};
+
 struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
                                struct proc_dir_entry *de)
 {
@@ -166,8 +412,12 @@ struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
                        inode->i_nlink = de->nlink;
                if (de->proc_iops)
                        inode->i_op = de->proc_iops;
-               if (de->proc_fops)
-                       inode->i_fop = de->proc_fops;
+               if (de->proc_fops) {
+                       if (S_ISREG(inode->i_mode))
+                               inode->i_fop = &proc_reg_file_ops;
+                       else
+                               inode->i_fop = de->proc_fops;
+               }
        }
 
        return inode;