error.c

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/*
 * linux/fs/9p/error.c
 *
 * Error string handling
 *
 * Plan 9 uses error strings, Unix uses error numbers.  These functions
 * try to help manage that and provide for dynamically adding error
 * mappings.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <[email protected]>
 *  Copyright (C) 2002 by Ron Minnich <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/errno.h>
#include <net/9p/9p.h>

struct errormap {
    char *name;
    int val;

    int namelen;
    struct hlist_node list;
};

#define ERRHASHSZ       32
static struct hlist_head hash_errmap[ERRHASHSZ];

/* FixMe - reduce to a reasonable size */
static struct errormap errmap[] = {
    {"Operation not permitted", EPERM},
    {"wstat prohibited", EPERM},
    {"No such file or directory", ENOENT},
    {"directory entry not found", ENOENT},
    {"file not found", ENOENT},
    {"Interrupted system call", EINTR},
    {"Input/output error", EIO},
    {"No such device or address", ENXIO},
    {"Argument list too long", E2BIG},
    {"Bad file descriptor", EBADF},
    {"Resource temporarily unavailable", EAGAIN},
    {"Cannot allocate memory", ENOMEM},
    {"Permission denied", EACCES},
    {"Bad address", EFAULT},
    {"Block device required", ENOTBLK},
    {"Device or resource busy", EBUSY},
    {"File exists", EEXIST},
    {"Invalid cross-device link", EXDEV},
    {"No such device", ENODEV},
    {"Not a directory", ENOTDIR},
    {"Is a directory", EISDIR},
    {"Invalid argument", EINVAL},
    {"Too many open files in system", ENFILE},
    {"Too many open files", EMFILE},
    {"Text file busy", ETXTBSY},
    {"File too large", EFBIG},
    {"No space left on device", ENOSPC},
    {"Illegal seek", ESPIPE},
    {"Read-only file system", EROFS},
    {"Too many links", EMLINK},
    {"Broken pipe", EPIPE},
    {"Numerical argument out of domain", EDOM},
    {"Numerical result out of range", ERANGE},
    {"Resource deadlock avoided", EDEADLK},
    {"File name too long", ENAMETOOLONG},
    {"No locks available", ENOLCK},
    {"Function not implemented", ENOSYS},
    {"Directory not empty", ENOTEMPTY},
    {"Too many levels of symbolic links", ELOOP},
    {"No message of desired type", ENOMSG},
    {"Identifier removed", EIDRM},
    {"No data available", ENODATA},
    {"Machine is not on the network", ENONET},
    {"Package not installed", ENOPKG},
    {"Object is remote", EREMOTE},
    {"Link has been severed", ENOLINK},
    {"Communication error on send", ECOMM},
    {"Protocol error", EPROTO},
    {"Bad message", EBADMSG},
    {"File descriptor in bad state", EBADFD},
    {"Streams pipe error", ESTRPIPE},
    {"Too many users", EUSERS},
    {"Socket operation on non-socket", ENOTSOCK},
    {"Message too long", EMSGSIZE},
    {"Protocol not available", ENOPROTOOPT},
    {"Protocol not supported", EPROTONOSUPPORT},
    {"Socket type not supported", ESOCKTNOSUPPORT},
    {"Operation not supported", EOPNOTSUPP},
    {"Protocol family not supported", EPFNOSUPPORT},
    {"Network is down", ENETDOWN},
    {"Network is unreachable", ENETUNREACH},
    {"Network dropped connection on reset", ENETRESET},
    {"Software caused connection abort", ECONNABORTED},
    {"Connection reset by peer", ECONNRESET},
    {"No buffer space available", ENOBUFS},
    {"Transport endpoint is already connected", EISCONN},
    {"Transport endpoint is not connected", ENOTCONN},
    {"Cannot send after transport endpoint shutdown", ESHUTDOWN},
    {"Connection timed out", ETIMEDOUT},
    {"Connection refused", ECONNREFUSED},
    {"Host is down", EHOSTDOWN},
    {"No route to host", EHOSTUNREACH},
    {"Operation already in progress", EALREADY},
    {"Operation now in progress", EINPROGRESS},
    {"Is a named type file", EISNAM},
    {"Remote I/O error", EREMOTEIO},
    {"Disk quota exceeded", EDQUOT},
/* errors from fossil, vacfs, and u9fs */
    {"fid unknown or out of range", EBADF},
    {"permission denied", EACCES},
    {"file does not exist", ENOENT},
    {"authentication failed", ECONNREFUSED},
    {"bad offset in directory read", ESPIPE},
    {"bad use of fid", EBADF},
    {"wstat can't convert between files and directories", EPERM},
    {"directory is not empty", ENOTEMPTY},
    {"file exists", EEXIST},
    {"file already exists", EEXIST},
    {"file or directory already exists", EEXIST},
    {"fid already in use", EBADF},
    {"file in use", ETXTBSY},
    {"i/o error", EIO},
    {"file already open for I/O", ETXTBSY},
    {"illegal mode", EINVAL},
    {"illegal name", ENAMETOOLONG},
    {"not a directory", ENOTDIR},
    {"not a member of proposed group", EPERM},
    {"not owner", EACCES},
    {"only owner can change group in wstat", EACCES},
    {"read only file system", EROFS},
    {"no access to special file", EPERM},
    {"i/o count too large", EIO},
    {"unknown group", EINVAL},
    {"unknown user", EINVAL},
    {"bogus wstat buffer", EPROTO},
    {"exclusive use file already open", EAGAIN},
    {"corrupted directory entry", EIO},
    {"corrupted file entry", EIO},
    {"corrupted block label", EIO},
    {"corrupted meta data", EIO},
    {"illegal offset", EINVAL},
    {"illegal path element", ENOENT},
    {"root of file system is corrupted", EIO},
    {"corrupted super block", EIO},
    {"protocol botch", EPROTO},
    {"file system is full", ENOSPC},
    {"file is in use", EAGAIN},
    {"directory entry is not allocated", ENOENT},
    {"file is read only", EROFS},
    {"file has been removed", EIDRM},
    {"only support truncation to zero length", EPERM},
    {"cannot remove root", EPERM},
    {"file too big", EFBIG},
    {"venti i/o error", EIO},
    /* these are not errors */
    {"u9fs rhostsauth: no authentication required", 0},
    {"u9fs authnone: no authentication required", 0},
    {NULL, -1}
};

int p9_error_init(void)
{
    struct errormap *c;
    int bucket;

    /* initialize hash table */
    for (bucket = 0; bucket < ERRHASHSZ; bucket++)
        INIT_HLIST_HEAD(&hash_errmap[bucket]);

    /* load initial error map into hash table */
    for (c = errmap; c->name != NULL; c++) {
        c->namelen = strlen(c->name);
        bucket = jhash(c->name, c->namelen, 0) % ERRHASHSZ;
        INIT_HLIST_NODE(&c->list);
        hlist_add_head(&c->list, &hash_errmap[bucket]);
    }

    return 1;
}
EXPORT_SYMBOL(p9_error_init);

int p9_errstr2errno(char *errstr, int len)
{
    int errno;
    struct hlist_node *p;
    struct errormap *c;
    int bucket;

    errno = 0;
    p = NULL;
    c = NULL;
    bucket = jhash(errstr, len, 0) % ERRHASHSZ;
    hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
        if (c->namelen == len && !memcmp(c->name, errstr, len)) {
            errno = c->val;
            break;
        }
    }

    if (errno == 0) {
        /* TODO: if error isn't found, add it dynamically */
        errstr[len] = 0;
        pr_err("%s: server reported unknown error %s\n",
               __func__, errstr);
        errno = ESERVERFAULT;
    }

    return -errno;
}
EXPORT_SYMBOL(p9_errstr2errno);