Commit d387a5c5 authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

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: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 839db3d1

fs/cifs/connect.c

+88 −7
Original line number Diff line number Diff line
@@ -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;

	}

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