root/fs/hfsplus/options.c

DEFINITIONS

1. hfsplus_fill_defaults
2. match_fourchar
3. hfsplus_parse_options
4. hfsplus_show_options

/*
 *  linux/fs/hfsplus/options.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Option parsing
 */

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/parser.h>
#include <linux/nls.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
#include "hfsplus_fs.h"

enum {
        opt_creator, opt_type,
        opt_umask, opt_uid, opt_gid,
        opt_part, opt_session, opt_nls,
        opt_nodecompose, opt_decompose,
        opt_force, opt_err
};

static const match_table_t tokens = {
        { opt_creator, "creator=%s" },
        { opt_type, "type=%s" },
        { opt_umask, "umask=%o" },
        { opt_uid, "uid=%u" },
        { opt_gid, "gid=%u" },
        { opt_part, "part=%u" },
        { opt_session, "session=%u" },
        { opt_nls, "nls=%s" },
        { opt_decompose, "decompose" },
        { opt_nodecompose, "nodecompose" },
        { opt_force, "force" },
        { opt_err, NULL }
};

/* Initialize an options object to reasonable defaults */
void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
{
        if (!opts)
                return;

        opts->creator = HFSPLUS_DEF_CR_TYPE;
        opts->type = HFSPLUS_DEF_CR_TYPE;
        opts->umask = current->fs->umask;
        opts->uid = current->uid;
        opts->gid = current->gid;
        opts->part = -1;
        opts->session = -1;
}

/* convert a "four byte character" to a 32 bit int with error checks */
static inline int match_fourchar(substring_t *arg, u32 *result)
{
        if (arg->to - arg->from != 4)
                return -EINVAL;
        memcpy(result, arg->from, 4);
        return 0;
}

/* Parse options from mount. Returns 0 on failure */
/* input is the options passed to mount() as a string */
int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
{
        char *p;
        substring_t args[MAX_OPT_ARGS];
        int tmp, token;

        if (!input)
                goto done;

        while ((p = strsep(&input, ",")) != NULL) {
                if (!*p)
                        continue;

                token = match_token(p, tokens, args);
                switch (token) {
                case opt_creator:
                        if (match_fourchar(&args[0], &sbi->creator)) {
                                printk(KERN_ERR "hfs: creator requires a 4 character value\n");
                                return 0;
                        }
                        break;
                case opt_type:
                        if (match_fourchar(&args[0], &sbi->type)) {
                                printk(KERN_ERR "hfs: type requires a 4 character value\n");
                                return 0;
                        }
                        break;
                case opt_umask:
                        if (match_octal(&args[0], &tmp)) {
                                printk(KERN_ERR "hfs: umask requires a value\n");
                                return 0;
                        }
                        sbi->umask = (umode_t)tmp;
                        break;
                case opt_uid:
                        if (match_int(&args[0], &tmp)) {
                                printk(KERN_ERR "hfs: uid requires an argument\n");
                                return 0;
                        }
                        sbi->uid = (uid_t)tmp;
                        break;
                case opt_gid:
                        if (match_int(&args[0], &tmp)) {
                                printk(KERN_ERR "hfs: gid requires an argument\n");
                                return 0;
                        }
                        sbi->gid = (gid_t)tmp;
                        break;
                case opt_part:
                        if (match_int(&args[0], &sbi->part)) {
                                printk(KERN_ERR "hfs: part requires an argument\n");
                                return 0;
                        }
                        break;
                case opt_session:
                        if (match_int(&args[0], &sbi->session)) {
                                printk(KERN_ERR "hfs: session requires an argument\n");
                                return 0;
                        }
                        break;
                case opt_nls:
                        if (sbi->nls) {
                                printk(KERN_ERR "hfs: unable to change nls mapping\n");
                                return 0;
                        }
                        p = match_strdup(&args[0]);
                        if (p)
                                sbi->nls = load_nls(p);
                        if (!sbi->nls) {
                                printk(KERN_ERR "hfs: unable to load nls mapping \"%s\"\n", p);
                                kfree(p);
                                return 0;
                        }
                        kfree(p);
                        break;
                case opt_decompose:
                        sbi->flags &= ~HFSPLUS_SB_NODECOMPOSE;
                        break;
                case opt_nodecompose:
                        sbi->flags |= HFSPLUS_SB_NODECOMPOSE;
                        break;
                case opt_force:
                        sbi->flags |= HFSPLUS_SB_FORCE;
                        break;
                default:
                        return 0;
                }
        }

done:
        if (!sbi->nls) {
                /* try utf8 first, as this is the old default behaviour */
                sbi->nls = load_nls("utf8");
                if (!sbi->nls)
                        sbi->nls = load_nls_default();
                if (!sbi->nls)
                        return 0;
        }

        return 1;
}

int hfsplus_show_options(struct seq_file *seq, struct vfsmount *mnt)
{
        struct hfsplus_sb_info *sbi = &HFSPLUS_SB(mnt->mnt_sb);

        if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
                seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
        if (sbi->type != HFSPLUS_DEF_CR_TYPE)
                seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
        seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask, sbi->uid, sbi->gid);
        if (sbi->part >= 0)
                seq_printf(seq, ",part=%u", sbi->part);
        if (sbi->session >= 0)
                seq_printf(seq, ",session=%u", sbi->session);
        if (sbi->nls)
                seq_printf(seq, ",nls=%s", sbi->nls->charset);
        if (sbi->flags & HFSPLUS_SB_NODECOMPOSE)
                seq_printf(seq, ",nodecompose");
        return 0;
}