diff options
Diffstat (limited to 'fs/proc/inode.c')
| -rw-r--r-- | fs/proc/inode.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/fs/proc/inode.c b/fs/proc/inode.c new file mode 100644 index 000000000000..133c28685105 --- /dev/null +++ b/fs/proc/inode.c @@ -0,0 +1,218 @@ +/* + * 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"); |