Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 705 insertions, 0 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
new file mode 100644
index 0000000..6c6315d
--- /dev/null
+++ b/fs/proc/generic.c
@@ -0,0 +1,705 @@
+/*
+ * 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/module.h>
+#include <linux/mount.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/idr.h>
+#include <linux/namei.h>
+#include <linux/bitops.h>
+#include <asm/uaccess.h>
+
+static ssize_t proc_file_read(struct file *file, char __user *buf,
+			      size_t nbytes, loff_t *ppos);
+static ssize_t proc_file_write(struct file *file, const char __user *buffer,
+			       size_t count, loff_t *ppos);
+static loff_t proc_file_lseek(struct file *, loff_t, int);
+
+int proc_match(int len, const char *name, struct proc_dir_entry *de)
+{
+	if (de->namelen != len)
+		return 0;
+	return !memcmp(name, de->name, len);
+}
+
+static struct file_operations proc_file_operations = {
+	.llseek		= proc_file_lseek,
+	.read		= proc_file_read,
+	.write		= proc_file_write,
+};
+
+/* buffer size is one page but our output routines use some slack for overruns */
+#define PROC_BLOCK_SIZE	(PAGE_SIZE - 1024)
+
+static ssize_t
+proc_file_read(struct file *file, char __user *buf, size_t nbytes,
+	       loff_t *ppos)
+{
+	struct inode * inode = file->f_dentry->d_inode;
+	char 	*page;
+	ssize_t	retval=0;
+	int	eof=0;
+	ssize_t	n, count;
+	char	*start;
+	struct proc_dir_entry * dp;
+
+	dp = PDE(inode);
+	if (!(page = (char*) __get_free_page(GFP_KERNEL)))
+		return -ENOMEM;
+
+	while ((nbytes > 0) && !eof) {
+		count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
+
+		start = NULL;
+		if (dp->get_info) {
+			/* Handle old net routines */
+			n = dp->get_info(page, &start, *ppos, count);
+			if (n < count)
+				eof = 1;
+		} else if (dp->read_proc) {
+			/*
+			 * How to be a proc read function
+			 * ------------------------------
+			 * Prototype:
+			 *    int f(char *buffer, char **start, off_t offset,
+			 *          int count, int *peof, void *dat)
+			 *
+			 * Assume that the buffer is "count" bytes in size.
+			 *
+			 * If you know you have supplied all the data you
+			 * have, set *peof.
+			 *
+			 * You have three ways to return data:
+			 * 0) Leave *start = NULL.  (This is the default.)
+			 *    Put the data of the requested offset at that
+			 *    offset within the buffer.  Return the number (n)
+			 *    of bytes there are from the beginning of the
+			 *    buffer up to the last byte of data.  If the
+			 *    number of supplied bytes (= n - offset) is 
+			 *    greater than zero and you didn't signal eof
+			 *    and the reader is prepared to take more data
+			 *    you will be called again with the requested
+			 *    offset advanced by the number of bytes 
+			 *    absorbed.  This interface is useful for files
+			 *    no larger than the buffer.
+			 * 1) Set *start = an unsigned long value less than
+			 *    the buffer address but greater than zero.
+			 *    Put the data of the requested offset at the
+			 *    beginning of the buffer.  Return the number of
+			 *    bytes of data placed there.  If this number is
+			 *    greater than zero and you didn't signal eof
+			 *    and the reader is prepared to take more data
+			 *    you will be called again with the requested
+			 *    offset advanced by *start.  This interface is
+			 *    useful when you have a large file consisting
+			 *    of a series of blocks which you want to count
+			 *    and return as wholes.
+			 *    (Hack by Paul.Russell@rustcorp.com.au)
+			 * 2) Set *start = an address within the buffer.
+			 *    Put the data of the requested offset at *start.
+			 *    Return the number of bytes of data placed there.
+			 *    If this number is greater than zero and you
+			 *    didn't signal eof and the reader is prepared to
+			 *    take more data you will be called again with the
+			 *    requested offset advanced by the number of bytes
+			 *    absorbed.
+			 */
+			n = dp->read_proc(page, &start, *ppos,
+					  count, &eof, dp->data);
+		} else
+			break;
+
+		if (n == 0)   /* end of file */
+			break;
+		if (n < 0) {  /* error */
+			if (retval == 0)
+				retval = n;
+			break;
+		}
+
+		if (start == NULL) {
+			if (n > PAGE_SIZE) {
+				printk(KERN_ERR
+				       "proc_file_read: Apparent buffer overflow!\n");
+				n = PAGE_SIZE;
+			}
+			n -= *ppos;
+			if (n <= 0)
+				break;
+			if (n > count)
+				n = count;
+			start = page + *ppos;
+		} else if (start < page) {
+			if (n > PAGE_SIZE) {
+				printk(KERN_ERR
+				       "proc_file_read: Apparent buffer overflow!\n");
+				n = PAGE_SIZE;
+			}
+			if (n > count) {
+				/*
+				 * Don't reduce n because doing so might
+				 * cut off part of a data block.
+				 */
+				printk(KERN_WARNING
+				       "proc_file_read: Read count exceeded\n");
+			}
+		} else /* start >= page */ {
+			unsigned long startoff = (unsigned long)(start - page);
+			if (n > (PAGE_SIZE - startoff)) {
+				printk(KERN_ERR
+				       "proc_file_read: Apparent buffer overflow!\n");
+				n = PAGE_SIZE - startoff;
+			}
+			if (n > count)
+				n = count;
+		}
+		
+ 		n -= copy_to_user(buf, start < page ? page : start, n);
+		if (n == 0) {
+			if (retval == 0)
+				retval = -EFAULT;
+			break;
+		}
+
+		*ppos += start < page ? (unsigned long)start : n;
+		nbytes -= n;
+		buf += n;
+		retval += n;
+	}
+	free_page((unsigned long) page);
+	return retval;
+}
+
+static ssize_t
+proc_file_write(struct file *file, const char __user *buffer,
+		size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct proc_dir_entry * dp;
+	
+	dp = PDE(inode);
+
+	if (!dp->write_proc)
+		return -EIO;
+
+	/* FIXME: does this routine need ppos?  probably... */
+	return dp->write_proc(file, buffer, count, dp->data);
+}
+
+
+static loff_t
+proc_file_lseek(struct file *file, loff_t offset, int orig)
+{
+    lock_kernel();
+
+    switch (orig) {
+    case 0:
+	if (offset < 0)
+	    goto out;
+	file->f_pos = offset;
+	unlock_kernel();
+	return(file->f_pos);
+    case 1:
+	if (offset + file->f_pos < 0)
+	    goto out;
+	file->f_pos += offset;
+	unlock_kernel();
+	return(file->f_pos);
+    case 2:
+	goto out;
+    default:
+	goto out;
+    }
+
+out:
+    unlock_kernel();
+    return -EINVAL;
+}
+
+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)
+		goto out;
+
+	error = inode_setattr(inode, iattr);
+	if (error)
+		goto out;
+	
+	de->uid = inode->i_uid;
+	de->gid = inode->i_gid;
+	de->mode = inode->i_mode;
+out:
+	return error;
+}
+
+static 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;
+	int			len;
+
+	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)
+			return -ENOENT;
+		cp += len + 1;
+	}
+	*residual = cp;
+	*ret = de;
+	return 0;
+}
+
+static DEFINE_IDR(proc_inum_idr);
+static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
+
+#define PROC_DYNAMIC_FIRST 0xF0000000UL
+
+/*
+ * Return an inode number between PROC_DYNAMIC_FIRST and
+ * 0xffffffff, or zero on failure.
+ */
+static unsigned int get_inode_number(void)
+{
+	int i, inum = 0;
+	int error;
+
+retry:
+	if (idr_pre_get(&proc_inum_idr, GFP_KERNEL) == 0)
+		return 0;
+
+	spin_lock(&proc_inum_lock);
+	error = idr_get_new(&proc_inum_idr, NULL, &i);
+	spin_unlock(&proc_inum_lock);
+	if (error == -EAGAIN)
+		goto retry;
+	else if (error)
+		return 0;
+
+	inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST;
+
+	/* inum will never be more than 0xf0ffffff, so no check
+	 * for overflow.
+	 */
+
+	return inum;
+}
+
+static void release_inode_number(unsigned int inum)
+{
+	int id = (inum - PROC_DYNAMIC_FIRST) | ~MAX_ID_MASK;
+
+	spin_lock(&proc_inum_lock);
+	idr_remove(&proc_inum_idr, id);
+	spin_unlock(&proc_inum_lock);
+}
+
+static int proc_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	nd_set_link(nd, PDE(dentry->d_inode)->data);
+	return 0;
+}
+
+static 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(struct dentry * dentry)
+{
+	return 1;
+}
+
+static 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(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+{
+	struct inode *inode = NULL;
+	struct proc_dir_entry * de;
+	int error = -ENOENT;
+
+	lock_kernel();
+	de = PDE(dir);
+	if (de) {
+		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)) {
+				unsigned int ino = de->low_ino;
+
+				error = -EINVAL;
+				inode = proc_get_inode(dir->i_sb, ino, de);
+				break;
+			}
+		}
+	}
+	unlock_kernel();
+
+	if (inode) {
+		dentry->d_op = &proc_dentry_operations;
+		d_add(dentry, inode);
+		return NULL;
+	}
+	return ERR_PTR(error);
+}
+
+/*
+ * 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(struct file * filp,
+	void * dirent, filldir_t filldir)
+{
+	struct proc_dir_entry * de;
+	unsigned int ino;
+	int i;
+	struct inode *inode = filp->f_dentry->d_inode;
+	int ret = 0;
+
+	lock_kernel();
+
+	ino = inode->i_ino;
+	de = PDE(inode);
+	if (!de) {
+		ret = -EINVAL;
+		goto out;
+	}
+	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_dentry),
+				    DT_DIR) < 0)
+				goto out;
+			i++;
+			filp->f_pos++;
+			/* fall through */
+		default:
+			de = de->subdir;
+			i -= 2;
+			for (;;) {
+				if (!de) {
+					ret = 1;
+					goto out;
+				}
+				if (!i)
+					break;
+				de = de->next;
+				i--;
+			}
+
+			do {
+				if (filldir(dirent, de->name, de->namelen, filp->f_pos,
+					    de->low_ino, de->mode >> 12) < 0)
+					goto out;
+				filp->f_pos++;
+				de = de->next;
+			} while (de);
+	}
+	ret = 1;
+out:	unlock_kernel();
+	return ret;	
+}
+
+/*
+ * These are the generic /proc directory operations. They
+ * use the in-memory "struct proc_dir_entry" tree to parse
+ * the /proc directory.
+ */
+static struct file_operations proc_dir_operations = {
+	.read			= generic_read_dir,
+	.readdir		= proc_readdir,
+};
+
+/*
+ * proc directories can do almost nothing..
+ */
+static struct inode_operations proc_dir_inode_operations = {
+	.lookup		= proc_lookup,
+	.setattr	= proc_notify_change,
+};
+
+static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
+{
+	unsigned int i;
+	
+	i = get_inode_number();
+	if (i == 0)
+		return -EAGAIN;
+	dp->low_ino = i;
+	dp->next = dir->subdir;
+	dp->parent = dir;
+	dir->subdir = dp;
+	if (S_ISDIR(dp->mode)) {
+		if (dp->proc_iops == NULL) {
+			dp->proc_fops = &proc_dir_operations;
+			dp->proc_iops = &proc_dir_inode_operations;
+		}
+		dir->nlink++;
+	} else if (S_ISLNK(dp->mode)) {
+		if (dp->proc_iops == NULL)
+			dp->proc_iops = &proc_link_inode_operations;
+	} else if (S_ISREG(dp->mode)) {
+		if (dp->proc_fops == NULL)
+			dp->proc_fops = &proc_file_operations;
+		if (dp->proc_iops == NULL)
+			dp->proc_iops = &proc_file_inode_operations;
+	}
+	return 0;
+}
+
+/*
+ * Kill an inode that got unregistered..
+ */
+static void proc_kill_inodes(struct proc_dir_entry *de)
+{
+	struct list_head *p;
+	struct super_block *sb = proc_mnt->mnt_sb;
+
+	/*
+	 * Actually it's a partial revoke().
+	 */
+	file_list_lock();
+	list_for_each(p, &sb->s_files) {
+		struct file * filp = list_entry(p, struct file, f_list);
+		struct dentry * dentry = filp->f_dentry;
+		struct inode * inode;
+		struct file_operations *fops;
+
+		if (dentry->d_op != &proc_dentry_operations)
+			continue;
+		inode = dentry->d_inode;
+		if (PDE(inode) != de)
+			continue;
+		fops = filp->f_op;
+		filp->f_op = NULL;
+		fops_put(fops);
+	}
+	file_list_unlock();
+}
+
+static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent,
+					  const char *name,
+					  mode_t mode,
+					  nlink_t nlink)
+{
+	struct proc_dir_entry *ent = NULL;
+	const char *fn = name;
+	int len;
+
+	/* make sure name is valid */
+	if (!name || !strlen(name)) goto out;
+
+	if (!(*parent) && 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 = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
+	if (!ent) goto out;
+
+	memset(ent, 0, sizeof(struct proc_dir_entry));
+	memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1);
+	ent->name = ((char *) ent) + sizeof(*ent);
+	ent->namelen = len;
+	ent->mode = mode;
+	ent->nlink = nlink;
+ 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;
+}
+
+struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
+		struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry *ent;
+
+	ent = proc_create(&parent, name, S_IFDIR | mode, 2);
+	if (ent) {
+		ent->proc_fops = &proc_dir_operations;
+		ent->proc_iops = &proc_dir_inode_operations;
+
+		if (proc_register(parent, ent) < 0) {
+			kfree(ent);
+			ent = NULL;
+		}
+	}
+	return ent;
+}
+
+struct proc_dir_entry *proc_mkdir(const char *name,
+		struct proc_dir_entry *parent)
+{
+	return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
+}
+
+struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
+					 struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry *ent;
+	nlink_t nlink;
+
+	if (S_ISDIR(mode)) {
+		if ((mode & S_IALLUGO) == 0)
+			mode |= S_IRUGO | S_IXUGO;
+		nlink = 2;
+	} else {
+		if ((mode & S_IFMT) == 0)
+			mode |= S_IFREG;
+		if ((mode & S_IALLUGO) == 0)
+			mode |= S_IRUGO;
+		nlink = 1;
+	}
+
+	ent = proc_create(&parent,name,mode,nlink);
+	if (ent) {
+		if (S_ISDIR(mode)) {
+			ent->proc_fops = &proc_dir_operations;
+			ent->proc_iops = &proc_dir_inode_operations;
+		}
+		if (proc_register(parent, ent) < 0) {
+			kfree(ent);
+			ent = NULL;
+		}
+	}
+	return ent;
+}
+
+void free_proc_entry(struct proc_dir_entry *de)
+{
+	unsigned int ino = de->low_ino;
+
+	if (ino < PROC_DYNAMIC_FIRST)
+		return;
+
+	release_inode_number(ino);
+
+	if (S_ISLNK(de->mode) && de->data)
+		kfree(de->data);
+	kfree(de);
+}
+
+/*
+ * Remove a /proc entry and free it if it's not currently in use.
+ * If it is in use, we set the 'deleted' flag.
+ */
+void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry **p;
+	struct proc_dir_entry *de;
+	const char *fn = name;
+	int len;
+
+	if (!parent && xlate_proc_name(name, &parent, &fn) != 0)
+		goto out;
+	len = strlen(fn);
+	for (p = &parent->subdir; *p; p=&(*p)->next ) {
+		if (!proc_match(len, fn, *p))
+			continue;
+		de = *p;
+		*p = de->next;
+		de->next = NULL;
+		if (S_ISDIR(de->mode))
+			parent->nlink--;
+		proc_kill_inodes(de);
+		de->nlink = 0;
+		WARN_ON(de->subdir);
+		if (!atomic_read(&de->count))
+			free_proc_entry(de);
+		else {
+			de->deleted = 1;
+			printk("remove_proc_entry: %s/%s busy, count=%d\n",
+				parent->name, de->name, atomic_read(&de->count));
+		}
+		break;
+	}
+out:
+	return;
+}