first commit

1 files changed, 639 insertions, 0 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
new file mode 100644
index 000000000..a2596afff
--- /dev/null
+++ b/fs/proc/generic.c
@@ -0,0 +1,639 @@
+/*
+ * proc/fs/generic.c --- generic routines for the proc-fs
+ *
+ * This file contains generic proc-fs routines for handling
+ * directories and files.
+ * 
+ * Copyright (C) 1991, 1992 Linus Torvalds.
+ * Copyright (C) 1997 Theodore Ts'o
+ */
+
+#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/printk.h>
+#include <linux/mount.h>
+#include <linux/init.h>
+#include <linux/idr.h>
+#include <linux/namei.h>
+#include <linux/bitops.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <asm/uaccess.h>
+
+#include "internal.h"
+
+DEFINE_SPINLOCK(proc_subdir_lock);
+
+static int proc_match(unsigned int len, const char *name, struct proc_dir_entry *de)
+{
+	if (de->namelen != len)
+		return 0;
+	return !memcmp(name, de->name, len);
+}
+
+static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
+{
+	struct inode *inode = dentry->d_inode;
+	struct proc_dir_entry *de = PDE(inode);
+	int error;
+
+	error = inode_change_ok(inode, iattr);
+	if (error)
+		return error;
+
+	setattr_copy(inode, iattr);
+	mark_inode_dirty(inode);
+
+	de->uid = inode->i_uid;
+	de->gid = inode->i_gid;
+	de->mode = inode->i_mode;
+	return 0;
+}
+
+static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
+			struct kstat *stat)
+{
+	struct inode *inode = dentry->d_inode;
+	struct proc_dir_entry *de = PROC_I(inode)->pde;
+	if (de && de->nlink)
+		set_nlink(inode, de->nlink);
+
+	generic_fillattr(inode, stat);
+	return 0;
+}
+
+static const struct inode_operations proc_file_inode_operations = {
+	.setattr	= proc_notify_change,
+};
+
+/*
+ * This function parses a name such as "tty/driver/serial", and
+ * returns the struct proc_dir_entry for "/proc/tty/driver", and
+ * returns "serial" in residual.
+ */
+static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
+			     const char **residual)
+{
+	const char     		*cp = name, *next;
+	struct proc_dir_entry	*de;
+	unsigned int		len;
+
+	de = *ret;
+	if (!de)
+		de = &proc_root;
+
+	while (1) {
+		next = strchr(cp, '/');
+		if (!next)
+			break;
+
+		len = next - cp;
+		for (de = de->subdir; de ; de = de->next) {
+			if (proc_match(len, cp, de))
+				break;
+		}
+		if (!de) {
+			WARN(1, "name '%s'\n", name);
+			return -ENOENT;
+		}
+		cp += len + 1;
+	}
+	*residual = cp;
+	*ret = de;
+	return 0;
+}
+
+static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
+			   const char **residual)
+{
+	int rv;
+
+	spin_lock(&proc_subdir_lock);
+	rv = __xlate_proc_name(name, ret, residual);
+	spin_unlock(&proc_subdir_lock);
+	return rv;
+}
+
+static DEFINE_IDA(proc_inum_ida);
+static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
+
+#define PROC_DYNAMIC_FIRST 0xF0000000U
+
+/*
+ * Return an inode number between PROC_DYNAMIC_FIRST and
+ * 0xffffffff, or zero on failure.
+ */
+int proc_alloc_inum(unsigned int *inum)
+{
+	unsigned int i;
+	int error;
+
+retry:
+	if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL))
+		return -ENOMEM;
+
+	spin_lock_irq(&proc_inum_lock);
+	error = ida_get_new(&proc_inum_ida, &i);
+	spin_unlock_irq(&proc_inum_lock);
+	if (error == -EAGAIN)
+		goto retry;
+	else if (error)
+		return error;
+
+	if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
+		spin_lock_irq(&proc_inum_lock);
+		ida_remove(&proc_inum_ida, i);
+		spin_unlock_irq(&proc_inum_lock);
+		return -ENOSPC;
+	}
+	*inum = PROC_DYNAMIC_FIRST + i;
+	return 0;
+}
+
+void proc_free_inum(unsigned int inum)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&proc_inum_lock, flags);
+	ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
+	spin_unlock_irqrestore(&proc_inum_lock, flags);
+}
+
+static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	nd_set_link(nd, __PDE_DATA(dentry->d_inode));
+	return NULL;
+}
+
+static const struct inode_operations proc_link_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= proc_follow_link,
+};
+
+/*
+ * As some entries in /proc are volatile, we want to 
+ * get rid of unused dentries.  This could be made 
+ * smarter: we could keep a "volatile" flag in the 
+ * inode to indicate which ones to keep.
+ */
+static int proc_delete_dentry(const struct dentry * dentry)
+{
+	return 1;
+}
+
+static const struct dentry_operations proc_dentry_operations =
+{
+	.d_delete	= proc_delete_dentry,
+};
+
+/*
+ * Don't create negative dentries here, return -ENOENT by hand
+ * instead.
+ */
+struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
+		struct dentry *dentry)
+{
+	struct inode *inode;
+
+	spin_lock(&proc_subdir_lock);
+	for (de = de->subdir; de ; de = de->next) {
+		if (de->namelen != dentry->d_name.len)
+			continue;
+		if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
+			pde_get(de);
+			spin_unlock(&proc_subdir_lock);
+			inode = proc_get_inode(dir->i_sb, de);
+			if (!inode)
+				return ERR_PTR(-ENOMEM);
+			d_set_d_op(dentry, &proc_dentry_operations);
+			d_add(dentry, inode);
+			return NULL;
+		}
+	}
+	spin_unlock(&proc_subdir_lock);
+	return ERR_PTR(-ENOENT);
+}
+
+struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
+		unsigned int flags)
+{
+	return proc_lookup_de(PDE(dir), dir, dentry);
+}
+
+/*
+ * This returns non-zero if at EOF, so that the /proc
+ * root directory can use this and check if it should
+ * continue with the <pid> entries..
+ *
+ * Note that the VFS-layer doesn't care about the return
+ * value of the readdir() call, as long as it's non-negative
+ * for success..
+ */
+int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
+		filldir_t filldir)
+{
+	unsigned int ino;
+	int i;
+	struct inode *inode = file_inode(filp);
+	int ret = 0;
+
+	ino = inode->i_ino;
+	i = filp->f_pos;
+	switch (i) {
+		case 0:
+			if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
+				goto out;
+			i++;
+			filp->f_pos++;
+			/* fall through */
+		case 1:
+			if (filldir(dirent, "..", 2, i,
+				    parent_ino(filp->f_path.dentry),
+				    DT_DIR) < 0)
+				goto out;
+			i++;
+			filp->f_pos++;
+			/* fall through */
+		default:
+			spin_lock(&proc_subdir_lock);
+			de = de->subdir;
+			i -= 2;
+			for (;;) {
+				if (!de) {
+					ret = 1;
+					spin_unlock(&proc_subdir_lock);
+					goto out;
+				}
+				if (!i)
+					break;
+				de = de->next;
+				i--;
+			}
+
+			do {
+				struct proc_dir_entry *next;
+
+				/* filldir passes info to user space */
+				pde_get(de);
+				spin_unlock(&proc_subdir_lock);
+				if (filldir(dirent, de->name, de->namelen, filp->f_pos,
+					    de->low_ino, de->mode >> 12) < 0) {
+					pde_put(de);
+					goto out;
+				}
+				spin_lock(&proc_subdir_lock);
+				filp->f_pos++;
+				next = de->next;
+				pde_put(de);
+				de = next;
+			} while (de);
+			spin_unlock(&proc_subdir_lock);
+	}
+	ret = 1;
+out:
+	return ret;	
+}
+
+int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	struct inode *inode = file_inode(filp);
+
+	return proc_readdir_de(PDE(inode), filp, dirent, filldir);
+}
+
+/*
+ * These are the generic /proc directory operations. They
+ * use the in-memory "struct proc_dir_entry" tree to parse
+ * the /proc directory.
+ */
+static const struct file_operations proc_dir_operations = {
+	.llseek			= generic_file_llseek,
+	.read			= generic_read_dir,
+	.readdir		= proc_readdir,
+};
+
+/*
+ * proc directories can do almost nothing..
+ */
+static const struct inode_operations proc_dir_inode_operations = {
+	.lookup		= proc_lookup,
+	.getattr	= proc_getattr,
+	.setattr	= proc_notify_change,
+};
+
+static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
+{
+	struct proc_dir_entry *tmp;
+	int ret;
+	
+	ret = proc_alloc_inum(&dp->low_ino);
+	if (ret)
+		return ret;
+
+	if (S_ISDIR(dp->mode)) {
+		dp->proc_fops = &proc_dir_operations;
+		dp->proc_iops = &proc_dir_inode_operations;
+		dir->nlink++;
+	} else if (S_ISLNK(dp->mode)) {
+		dp->proc_iops = &proc_link_inode_operations;
+	} else if (S_ISREG(dp->mode)) {
+		BUG_ON(dp->proc_fops == NULL);
+		dp->proc_iops = &proc_file_inode_operations;
+	} else {
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	spin_lock(&proc_subdir_lock);
+
+	for (tmp = dir->subdir; tmp; tmp = tmp->next)
+		if (strcmp(tmp->name, dp->name) == 0) {
+			WARN(1, "proc_dir_entry '%s/%s' already registered\n",
+				dir->name, dp->name);
+			break;
+		}
+
+	dp->next = dir->subdir;
+	dp->parent = dir;
+	dir->subdir = dp;
+	spin_unlock(&proc_subdir_lock);
+
+	return 0;
+}
+
+static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
+					  const char *name,
+					  umode_t mode,
+					  nlink_t nlink)
+{
+	struct proc_dir_entry *ent = NULL;
+	const char *fn = name;
+	unsigned int len;
+
+	/* make sure name is valid */
+	if (!name || !strlen(name))
+		goto out;
+
+	if (xlate_proc_name(name, parent, &fn) != 0)
+		goto out;
+
+	/* At this point there must not be any '/' characters beyond *fn */
+	if (strchr(fn, '/'))
+		goto out;
+
+	len = strlen(fn);
+
+	ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
+	if (!ent)
+		goto out;
+
+	memcpy(ent->name, fn, len + 1);
+	ent->namelen = len;
+	ent->mode = mode;
+	ent->nlink = nlink;
+	atomic_set(&ent->count, 1);
+	spin_lock_init(&ent->pde_unload_lock);
+	INIT_LIST_HEAD(&ent->pde_openers);
+out:
+	return ent;
+}
+
+struct proc_dir_entry *proc_symlink(const char *name,
+		struct proc_dir_entry *parent, const char *dest)
+{
+	struct proc_dir_entry *ent;
+
+	ent = __proc_create(&parent, name,
+			  (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
+
+	if (ent) {
+		ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
+		if (ent->data) {
+			strcpy((char*)ent->data,dest);
+			if (proc_register(parent, ent) < 0) {
+				kfree(ent->data);
+				kfree(ent);
+				ent = NULL;
+			}
+		} else {
+			kfree(ent);
+			ent = NULL;
+		}
+	}
+	return ent;
+}
+EXPORT_SYMBOL(proc_symlink);
+
+struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
+		struct proc_dir_entry *parent, void *data)
+{
+	struct proc_dir_entry *ent;
+
+	if (mode == 0)
+		mode = S_IRUGO | S_IXUGO;
+
+	ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
+	if (ent) {
+		ent->data = data;
+		if (proc_register(parent, ent) < 0) {
+			kfree(ent);
+			ent = NULL;
+		}
+	}
+	return ent;
+}
+EXPORT_SYMBOL_GPL(proc_mkdir_data);
+
+struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
+				       struct proc_dir_entry *parent)
+{
+	return proc_mkdir_data(name, mode, parent, NULL);
+}
+EXPORT_SYMBOL(proc_mkdir_mode);
+
+struct proc_dir_entry *proc_mkdir(const char *name,
+		struct proc_dir_entry *parent)
+{
+	return proc_mkdir_data(name, 0, parent, NULL);
+}
+EXPORT_SYMBOL(proc_mkdir);
+
+struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
+					struct proc_dir_entry *parent,
+					const struct file_operations *proc_fops,
+					void *data)
+{
+	struct proc_dir_entry *pde;
+	if ((mode & S_IFMT) == 0)
+		mode |= S_IFREG;
+
+	if (!S_ISREG(mode)) {
+		WARN_ON(1);	/* use proc_mkdir() */
+		return NULL;
+	}
+
+	if ((mode & S_IALLUGO) == 0)
+		mode |= S_IRUGO;
+	pde = __proc_create(&parent, name, mode, 1);
+	if (!pde)
+		goto out;
+	pde->proc_fops = proc_fops;
+	pde->data = data;
+	if (proc_register(parent, pde) < 0)
+		goto out_free;
+	return pde;
+out_free:
+	kfree(pde);
+out:
+	return NULL;
+}
+EXPORT_SYMBOL(proc_create_data);
+ 
+void proc_set_size(struct proc_dir_entry *de, loff_t size)
+{
+	de->size = size;
+}
+EXPORT_SYMBOL(proc_set_size);
+
+void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid)
+{
+	de->uid = uid;
+	de->gid = gid;
+}
+EXPORT_SYMBOL(proc_set_user);
+
+static void free_proc_entry(struct proc_dir_entry *de)
+{
+	proc_free_inum(de->low_ino);
+
+	if (S_ISLNK(de->mode))
+		kfree(de->data);
+	kfree(de);
+}
+
+void pde_put(struct proc_dir_entry *pde)
+{
+	if (atomic_dec_and_test(&pde->count))
+		free_proc_entry(pde);
+}
+
+/*
+ * Remove a /proc entry and free it if it's not currently in use.
+ */
+void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry **p;
+	struct proc_dir_entry *de = NULL;
+	const char *fn = name;
+	unsigned int len;
+
+	spin_lock(&proc_subdir_lock);
+	if (__xlate_proc_name(name, &parent, &fn) != 0) {
+		spin_unlock(&proc_subdir_lock);
+		return;
+	}
+	len = strlen(fn);
+
+	for (p = &parent->subdir; *p; p=&(*p)->next ) {
+		if (proc_match(len, fn, *p)) {
+			de = *p;
+			*p = de->next;
+			de->next = NULL;
+			break;
+		}
+	}
+	spin_unlock(&proc_subdir_lock);
+	if (!de) {
+		WARN(1, "name '%s'\n", name);
+		return;
+	}
+
+	proc_entry_rundown(de);
+
+	if (S_ISDIR(de->mode))
+		parent->nlink--;
+	de->nlink = 0;
+	WARN(de->subdir, "%s: removing non-empty directory "
+			 "'%s/%s', leaking at least '%s'\n", __func__,
+			 de->parent->name, de->name, de->subdir->name);
+	pde_put(de);
+}
+EXPORT_SYMBOL(remove_proc_entry);
+
+int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry **p;
+	struct proc_dir_entry *root = NULL, *de, *next;
+	const char *fn = name;
+	unsigned int len;
+
+	spin_lock(&proc_subdir_lock);
+	if (__xlate_proc_name(name, &parent, &fn) != 0) {
+		spin_unlock(&proc_subdir_lock);
+		return -ENOENT;
+	}
+	len = strlen(fn);
+
+	for (p = &parent->subdir; *p; p=&(*p)->next ) {
+		if (proc_match(len, fn, *p)) {
+			root = *p;
+			*p = root->next;
+			root->next = NULL;
+			break;
+		}
+	}
+	if (!root) {
+		spin_unlock(&proc_subdir_lock);
+		return -ENOENT;
+	}
+	de = root;
+	while (1) {
+		next = de->subdir;
+		if (next) {
+			de->subdir = next->next;
+			next->next = NULL;
+			de = next;
+			continue;
+		}
+		spin_unlock(&proc_subdir_lock);
+
+		proc_entry_rundown(de);
+		next = de->parent;
+		if (S_ISDIR(de->mode))
+			next->nlink--;
+		de->nlink = 0;
+		if (de == root)
+			break;
+		pde_put(de);
+
+		spin_lock(&proc_subdir_lock);
+		de = next;
+	}
+	pde_put(root);
+	return 0;
+}
+EXPORT_SYMBOL(remove_proc_subtree);
+
+void *proc_get_parent_data(const struct inode *inode)
+{
+	struct proc_dir_entry *de = PDE(inode);
+	return de->parent->data;
+}
+EXPORT_SYMBOL_GPL(proc_get_parent_data);
+
+void proc_remove(struct proc_dir_entry *de)
+{
+	if (de)
+		remove_proc_subtree(de->name, de->parent);
+}
+EXPORT_SYMBOL(proc_remove);
+
+void *PDE_DATA(const struct inode *inode)
+{
+	return __PDE_DATA(inode);
+}
+EXPORT_SYMBOL(PDE_DATA);