/* * linux/fs/proc/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/time.h> #include <linux/proc_fs.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/stat.h> #include <linux/file.h> #include <linux/limits.h> #include <linux/init.h> #include <linux/module.h> #include <linux/smp_lock.h> #include <asm/system.h> #include <asm/uaccess.h> extern void free_proc_entry(struct proc_dir_entry *); static inline struct proc_dir_entry * de_get(struct proc_dir_entry *de) { if (de) atomic_inc(&de->count); return de; } /* * Decrements the use count and checks for deferred deletion. */ static void de_put(struct proc_dir_entry *de) { if (de) { lock_kernel(); if (!atomic_read(&de->count)) { printk("de_put: entry %s already free!\n", de->name); unlock_kernel(); return; } if (atomic_dec_and_test(&de->count)) { if (de->deleted) { printk("de_put: deferred delete of %s\n", de->name); free_proc_entry(de); } } unlock_kernel(); } } /* * Decrement the use count of the proc_dir_entry. */ static void proc_delete_inode(struct inode *inode) { struct proc_dir_entry *de; struct task_struct *tsk; /* Let go of any associated process */ tsk = PROC_I(inode)->task; if (tsk) put_task_struct(tsk); /* Let go of any associated proc directory entry */ de = PROC_I(inode)->pde; if (de) { if (de->owner) module_put(de->owner); de_put(de); } clear_inode(inode); } struct vfsmount *proc_mnt; static void proc_read_inode(struct inode * inode) { inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; } static kmem_cache_t * proc_inode_cachep; static struct inode *proc_alloc_inode(struct super_block *sb) { struct proc_inode *ei; struct inode *inode; ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, SLAB_KERNEL); if (!ei) return NULL; ei->task = NULL; ei->type = 0; ei->op.proc_get_link = NULL; ei->pde = NULL; inode = &ei->vfs_inode; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; return inode; } static void proc_destroy_inode(struct inode *inode) { kmem_cache_free(proc_inode_cachep, PROC_I(inode)); } static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) { struct proc_inode *ei = (struct proc_inode *) foo; if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR) 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, init_once, NULL); if (proc_inode_cachep == NULL) return -ENOMEM; return 0; } static int proc_remount(struct super_block *sb, int *flags, char *data) { *flags |= MS_NODIRATIME; return 0; } static struct super_operations proc_sops = { .alloc_inode = proc_alloc_inode, .destroy_inode = proc_destroy_inode, .read_inode = proc_read_inode, .drop_inode = generic_delete_inode, .delete_inode = proc_delete_inode, .statfs = simple_statfs, .remount_fs = proc_remount, }; struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, struct proc_dir_entry *de) { struct inode * inode; /* * Increment the use count so the dir entry can't disappear. */ de_get(de); WARN_ON(de && de->deleted); inode = iget(sb, ino); if (!inode) goto out_fail; PROC_I(inode)->pde = de; if (de) { if (de->mode) { inode->i_mode = de->mode; inode->i_uid = de->uid; inode->i_gid = de->gid; } if (de->size) inode->i_size = de->size; if (de->nlink) inode->i_nlink = de->nlink; if (!try_module_get(de->owner)) goto out_fail; if (de->proc_iops) inode->i_op = de->proc_iops; if (de->proc_fops) inode->i_fop = de->proc_fops; } out: return inode; out_fail: de_put(de); goto out; } int proc_fill_super(struct super_block *s, void *data, int silent) { struct inode * root_inode; s->s_flags |= MS_NODIRATIME; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = PROC_SUPER_MAGIC; s->s_op = &proc_sops; s->s_time_gran = 1; root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root); if (!root_inode) goto out_no_root; /* * Fixup the root inode's nlink value */ root_inode->i_nlink += nr_processes(); root_inode->i_uid = 0; root_inode->i_gid = 0; s->s_root = d_alloc_root(root_inode); if (!s->s_root) goto out_no_root; return 0; out_no_root: printk("proc_read_super: get root inode failed\n"); iput(root_inode); return -ENOMEM; } MODULE_LICENSE("GPL");