patch-2.1.28 linux/fs/proc/generic.c

• Lines: 196
• Date: Fri Feb 28 15:00:55 1997
• Orig file: v2.1.27/linux/fs/proc/generic.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.27/linux/fs/proc/generic.c linux/fs/proc/generic.c
@@ -0,0 +1,195 @@
+/*
+ * 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 <asm/uaccess.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/config.h>
+#include <asm/bitops.h>
+
+static long proc_file_read(struct inode * inode, struct file * file,
+			   char * buf, unsigned long nbytes);
+static long proc_file_write(struct inode * inode, struct file * file,
+			    const char * buffer, unsigned long count);
+static long long proc_file_lseek(struct inode * inode, struct file * file, 
+				 long long offset, int orig);
+
+static struct file_operations proc_file_operations = {
+    proc_file_lseek,	/* lseek   */
+    proc_file_read,	/* read	   */
+    proc_file_write,	/* write   */
+    NULL,		/* readdir */
+    NULL,		/* poll    */
+    NULL,		/* ioctl   */
+    NULL,		/* mmap	   */
+    NULL,		/* no special open code	   */
+    NULL,		/* no special release code */
+    NULL		/* can't fsync */
+};
+
+/*
+ * proc files can do almost nothing..
+ */
+struct inode_operations proc_file_inode_operations = {
+    &proc_file_operations,  /* default scsi directory file-ops */
+    NULL,	    /* create	   */
+    NULL,	    /* lookup	   */
+    NULL,	    /* link	   */
+    NULL,	    /* unlink	   */
+    NULL,	    /* symlink	   */
+    NULL,	    /* mkdir	   */
+    NULL,	    /* rmdir	   */
+    NULL,	    /* mknod	   */
+    NULL,	    /* rename	   */
+    NULL,	    /* readlink	   */
+    NULL,	    /* follow_link */
+    NULL,	    /* readpage	   */
+    NULL,	    /* writepage   */
+    NULL,	    /* bmap	   */
+    NULL,	    /* truncate	   */
+    NULL	    /* permission  */
+};
+
+#ifndef MIN
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/* 4K page size but our output routines use some slack for overruns */
+#define PROC_BLOCK_SIZE	(3*1024)
+
+static long proc_file_read(struct inode * inode, struct file * file,
+			   char * buf, unsigned long nbytes)
+{
+	char 	*page;
+	int	retval=0;
+	int	n;
+	char	*start;
+	struct proc_dir_entry * dp;
+
+	if (nbytes < 0)
+		return -EINVAL;
+	dp = (struct proc_dir_entry *) inode->u.generic_ip;
+	if (!(page = (char*) __get_free_page(GFP_KERNEL)))
+		return -ENOMEM;
+
+	while (nbytes > 0)
+	{
+		n = MIN(PROC_BLOCK_SIZE, nbytes);
+
+		if (dp->get_info) {
+			/*
+			 * Handle backwards compatibility with the old net
+			 * routines.
+			 * 
+			 * XXX What gives with the file->f_flags & O_ACCMODE
+			 * test?  Seems stupid to me....
+			 */
+			n = dp->get_info(page, &start, file->f_pos, n,
+				 (file->f_flags & O_ACCMODE) == O_RDWR);
+		} else if (dp->read_proc) {
+			n = dp->read_proc(page, &start, file->f_pos,
+					  n, dp->data);
+		} else
+			break;
+			
+		if (n == 0)
+			break;	/* End of file */
+		if (n < 0) {
+			if (retval == 0)
+				retval = n;
+			break;
+		}
+		
+		n -= copy_to_user(buf, start, n);
+		if (n == 0) {
+			if (retval == 0)
+				retval = -EFAULT;
+			break;
+		}
+		
+		file->f_pos += n;	/* Move down the file */
+		nbytes -= n;
+		buf += n;
+		retval += n;
+	}
+	free_page((unsigned long) page);
+	return retval;
+}
+
+static long
+proc_file_write(struct inode * inode, struct file * file,
+		const char * buffer, unsigned long count)
+{
+	struct proc_dir_entry * dp;
+	char 	*page;
+	
+	if (count < 0)
+		return -EINVAL;
+	dp = (struct proc_dir_entry *) inode->u.generic_ip;
+	if (!(page = (char*) __get_free_page(GFP_KERNEL)))
+		return -ENOMEM;
+
+	if (!dp->write_proc)
+		return -EIO;
+
+	return dp->write_proc(file, buffer, count, dp->data);
+}
+
+
+
+static long long proc_file_lseek(struct inode * inode, struct file * file, 
+				 long long offset, int orig)
+{
+    switch (orig) {
+    case 0:
+	file->f_pos = offset;
+	return(file->f_pos);
+    case 1:
+	file->f_pos += offset;
+	return(file->f_pos);
+    case 2:
+	return(-EINVAL);
+    default:
+	return(-EINVAL);
+    }
+}
+
+struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
+					 struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry *ent;
+
+	ent = kmalloc(sizeof(struct proc_dir_entry), GFP_KERNEL);
+	if (!ent)
+		return NULL;
+	memset(ent, 0, sizeof(struct proc_dir_entry));
+
+	if (mode == S_IFDIR)
+		mode |= S_IRUGO | S_IXUGO;
+	else if (mode == 0)
+		mode = S_IFREG | S_IRUGO;
+	
+	ent->name = name;
+	ent->namelen = strlen(ent->name);
+	ent->mode = mode;
+	if (S_ISDIR(mode)) 
+		ent->nlink = 2;
+	else
+		ent->nlink = 1;
+
+	if (parent)
+		proc_register(parent, ent);
+	
+	return ent;
+}
+