[Cluster-devel] [PATCH] gfs2: Fix handling of mount points with spaces
David Teigland
teigland at redhat.com
Mon Apr 26 20:20:30 UTC 2010
On Mon, Apr 26, 2010 at 04:09:25PM -0400, Lon Hohberger wrote:
> Mount points may contain spaces, tabs, newlines, and the
> backslash character according to getmntent(3). Unfortunately,
> while scanning /proc/mounts, mount.gfs2 was not unescaping
> the escape sequences, causing mount.gfs2 to not update mtab.
>
> Utilities relying on mtab (e.g. fuser) would consequently
> be unable to list processes holding references on the mount
> point.
Looks good.
> Resolves: rhbz#586100
>
> Signed-off-by: Lon Hohberger <lhh at redhat.com>
> ---
> gfs2/mount/util.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 53 insertions(+), 2 deletions(-)
>
> diff --git a/gfs2/mount/util.c b/gfs2/mount/util.c
> index 16fc382..bc26daf 100644
> --- a/gfs2/mount/util.c
> +++ b/gfs2/mount/util.c
> @@ -201,6 +201,48 @@ void parse_opts(struct mount_options *mo)
> log_debug("parse_opts: locktable = \"%s\"", mo->locktable);
> }
>
> +/* Remove escape sequences from mount path. Per getmntent(3), there are
> + only four escape sequences we need to handle. Consequently, this does
> + not need to be a general-purpose unescape function */
> +
> +static int mnt_unescape(char *dest, size_t len, const char *src)
> +{
> + unsigned i = 0, j = 0;
> + size_t srclen;
> + int ret = -1;
> +
> + srclen = strlen(src);
> + while (i < srclen) {
> + if (src[i] != '\\') {
> + dest[j] = src[i];
> + ++i; ++j;
> + continue;
> + }
> +
> + ++i;
> + if ((srclen - 3) < i)
> + return -1;
> +
> + if (!strncmp(&src[i], "040", 3)) {
> + dest[j] = ' ';
> + } else if (!strncmp(&src[i], "011", 3)) {
> + dest[j] = '\t';
> + } else if (!strncmp(&src[i], "012", 3)) {
> + dest[j] = '\n';
> + } else if (!strncmp(&src[i], "134", 3)) {
> + dest[j] = '\\';
> + } else {
> + return -1;
> + }
> +
> + i+=3;
> + j++;
> + }
> +
> + return 0;
> +}
> +
> +
> /* - when unmounting, we don't know the dev and need this function to set it;
> we also want to select the _last_ line with a matching dir since it will
> be the top-most fs that the umount(2) will unmount
> @@ -212,6 +254,7 @@ void read_proc_mounts(struct mount_options *mo)
> FILE *file;
> char line[PATH_MAX];
> char path[PATH_MAX];
> + char unescaped_path[PATH_MAX];
> char type[PATH_MAX];
> char opts[PATH_MAX];
> char device[PATH_MAX];
> @@ -234,8 +277,16 @@ void read_proc_mounts(struct mount_options *mo)
> while (fgets(line, PATH_MAX, file)) {
> if (sscanf(line, "%s %s %s %s", device, path, type, opts) != 4)
> continue;
> - if (strcmp(path, mo->dir))
> - continue;
> + if (strcmp(path, mo->dir)) {
> + if (!strchr(path, '\\'))
> + continue;
> + /* /proc/mounts entry may have escaped spaces */
> + if (mnt_unescape(unescaped_path, sizeof(unescaped_path),
> + path) < 0)
> + continue;
> + if (strcmp(unescaped_path, mo->dir))
> + continue;
> + }
> if (mo->dev[0]) {
> if (stat(device, &st_mounts_dev))
> continue;
> --
> 1.6.2.5
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