From 19c9bba94152148523ba0f7ef7cffe3d45656b11 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 29 Apr 1997 21:13:14 +0000 Subject: Import of Linux/MIPS 2.1.36 --- fs/proc/generic.c | 289 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 289 insertions(+) create mode 100644 fs/proc/generic.c (limited to 'fs/proc/generic.c') diff --git a/fs/proc/generic.c b/fs/proc/generic.c new file mode 100644 index 000000000..6e80e8298 --- /dev/null +++ b/fs/proc/generic.c @@ -0,0 +1,289 @@ +/* + * 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 + +#include +#include +#include +#include +#include + +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 proc 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 */ +}; + +/* + * compatibility to replace fs/proc/net.c + */ +struct inode_operations proc_net_inode_operations = { + &proc_file_operations, /* default net 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 eof=0; + int n, count; + 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) && !eof) + { + count = MIN(PROC_BLOCK_SIZE, nbytes); + + start = NULL; + 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, count, + (file->f_flags & O_ACCMODE) == O_RDWR); + if (n < count) + eof = 1; + } else if (dp->read_proc) { + n = dp->read_proc(page, &start, file->f_pos, + count, &eof, dp->data); + } else + break; + + if (!start) { + /* + * For proc files that are less than 4k + */ + start = page + file->f_pos; + n -= file->f_pos; + if (n <= 0) + break; + if (n > count) + n = count; + } + 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; + + if (count < 0) + return -EINVAL; + dp = (struct proc_dir_entry *) inode->u.generic_ip; + + 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); + } +} + +/* + * 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; +} + +struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode, + struct proc_dir_entry *parent) +{ + struct proc_dir_entry *ent; + const char *fn; + + if (parent) + fn = name; + else { + if (xlate_proc_name(name, &parent, &fn)) + return NULL; + } + + 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 = fn; + ent->namelen = strlen(fn); + ent->mode = mode; + if (S_ISDIR(mode)) + ent->nlink = 2; + else + ent->nlink = 1; + + proc_register(parent, ent); + + return ent; +} + +void remove_proc_entry(const char *name, struct proc_dir_entry *parent) +{ + struct proc_dir_entry *de; + const char *fn; + int len; + + if (parent) + fn = name; + else + if (xlate_proc_name(name, &parent, &fn)) + return; + len = strlen(fn); + + for (de = parent->subdir; de ; de = de->next) { + if (proc_match(len, fn, de)) + break; + } + if (de) + proc_unregister(parent, de->low_ino); + kfree(de); +} -- cgit v1.2.3