cifs: parse the device name into UNC and prepath

This should fix a regression that was introduced when the new mount
option parser went in. Also, when the unc= and prefixpath= options
are provided, check their values against the ones we parsed from
the device string. If they differ, then throw a warning that tells
the user that we're using the values from the unc= option for now,
but that that will change in 3.10.

Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Jeff Layton 2012-12-10 06:10:46 -05:00 committed by Steve French
parent 839db3d10a
commit d387a5c50b
1 changed files with 88 additions and 7 deletions

View File

@ -1096,6 +1096,52 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol)
return 0;
}
/*
* Parse a devname into substrings and populate the vol->UNC and vol->prepath
* fields with the result. Returns 0 on success and an error otherwise.
*/
static int
cifs_parse_devname(const char *devname, struct smb_vol *vol)
{
char *pos;
const char *delims = "/\\";
size_t len;
/* make sure we have a valid UNC double delimiter prefix */
len = strspn(devname, delims);
if (len != 2)
return -EINVAL;
/* find delimiter between host and sharename */
pos = strpbrk(devname + 2, delims);
if (!pos)
return -EINVAL;
/* skip past delimiter */
++pos;
/* now go until next delimiter or end of string */
len = strcspn(pos, delims);
/* move "pos" up to delimiter or NULL */
pos += len;
vol->UNC = kstrndup(devname, pos - devname, GFP_KERNEL);
if (!vol->UNC)
return -ENOMEM;
convert_delimiter(vol->UNC, '\\');
/* If pos is NULL, or is a bogus trailing delimiter then no prepath */
if (!*pos++ || !*pos)
return 0;
vol->prepath = kstrdup(pos, GFP_KERNEL);
if (!vol->prepath)
return -ENOMEM;
return 0;
}
static int
cifs_parse_mount_options(const char *mountdata, const char *devname,
struct smb_vol *vol)
@ -1181,6 +1227,16 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
vol->backupuid_specified = false; /* no backup intent for a user */
vol->backupgid_specified = false; /* no backup intent for a group */
/*
* For now, we ignore -EINVAL errors under the assumption that the
* unc= and prefixpath= options will be usable.
*/
if (cifs_parse_devname(devname, vol) == -ENOMEM) {
printk(KERN_ERR "CIFS: Unable to allocate memory to parse "
"device string.\n");
goto out_nomem;
}
while ((data = strsep(&options, separator)) != NULL) {
substring_t args[MAX_OPT_ARGS];
unsigned long option;
@ -1566,18 +1622,31 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
got_ip = true;
break;
case Opt_unc:
kfree(vol->UNC);
string = vol->UNC;
vol->UNC = match_strdup(args);
if (vol->UNC == NULL)
if (vol->UNC == NULL) {
kfree(string);
goto out_nomem;
}
convert_delimiter(vol->UNC, '\\');
if (vol->UNC[0] != '\\' || vol->UNC[1] != '\\') {
printk(KERN_WARNING "CIFS: UNC Path does not "
kfree(string);
printk(KERN_ERR "CIFS: UNC Path does not "
"begin with // or \\\\\n");
goto cifs_parse_mount_err;
}
/* Compare old unc= option to new one */
if (!string || strcmp(string, vol->UNC))
printk(KERN_WARNING "CIFS: the value of the "
"unc= mount option does not match the "
"device string. Using the unc= option "
"for now. In 3.10, that option will "
"be ignored and the contents of the "
"device string will be used "
"instead. (%s != %s)\n", string,
vol->UNC);
break;
case Opt_domain:
string = match_strdup(args);
@ -1616,10 +1685,22 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
if (*args[0].from == '/' || *args[0].from == '\\')
args[0].from++;
kfree(vol->prepath);
string = vol->prepath;
vol->prepath = match_strdup(args);
if (vol->prepath == NULL)
if (vol->prepath == NULL) {
kfree(string);
goto out_nomem;
}
/* Compare old prefixpath= option to new one */
if (!string || strcmp(string, vol->prepath))
printk(KERN_WARNING "CIFS: the value of the "
"prefixpath= mount option does not "
"match the device string. Using the "
"prefixpath= option for now. In 3.10, "
"that option will be ignored and the "
"contents of the device string will be "
"used instead.(%s != %s)\n", string,
vol->prepath);
break;
case Opt_iocharset:
string = match_strdup(args);
@ -1777,8 +1858,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
}
#endif
if (!vol->UNC) {
cERROR(1, "CIFS mount error: No UNC path (e.g. -o "
"unc=\\\\192.168.1.100\\public) specified");
cERROR(1, "CIFS mount error: No usable UNC path provided in "
"device string or in unc= option!");
goto cifs_parse_mount_err;
}