LU-12650 lib: fix strings comparison during mount searching

get_root_path() returns path to "lustre" mount instead "lustre1"
because last symbol is not taking in account during comparison.
This bug has influence to get_root_path() users.

For example, fid2path use get_root_path().

lfs path2fid /mnt/lustre2/foodir3
[0x200000401:0x1:0x0]

lfs fid2path lustre2 [0x200000401:0x1:0x0]
lfs fid2path: cannot find '[0x200000401:0x1:0x0]': No such file or
directory

umount /mnt/lustre
lfs fid2path lustre2 [0x200000401:0x1:0x0]
foodir3

This fix adds strings length comparison.

Signed-off-by: Artem Blagodarenko <c17828@cray.com>
Cray-bug-id: LUS-7693
Change-Id: I3275d2182486d25389814f4c25b3f2a54ec29469
Reviewed-on: https://review.whamcloud.com/35755
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexander Zarochentsev <c17826@cray.com>

diff --git a/lustre/utils/liblustreapi.c b/lustre/utils/liblustreapi.c
index 59d02de..d9962aa 100644 (file)
--- a/lustre/utils/liblustreapi.c
+++ b/lustre/utils/liblustreapi.c
@@ -1261,6 +1261,7 @@ int get_root_path(int want, char *fsname, int *outfd, char *path, int index)
        FILE *fp;
        int idx = 0, len = 0, mntlen, fd;
        int rc = -ENODEV;
+       int fsnamelen, mountlen;
 
         /* get the mount point */
        fp = setmntent(PROC_MOUNTS, "r");
@@ -1294,18 +1295,20 @@ int get_root_path(int want, char *fsname, int *outfd, char *path, int index)
                        ptr_end++;
 
                /* Check the fsname for a match, if given */
+               mountlen = ptr_end - ptr;
                 if (!(want & WANT_FSNAME) && fsname != NULL &&
-                   (strlen(fsname) > 0) &&
-                   (strncmp(ptr, fsname, ptr_end - ptr) != 0))
-                        continue;
+                   (fsnamelen = strlen(fsname)) > 0 &&
+                   (fsnamelen != mountlen ||
+                   (strncmp(ptr, fsname, mountlen) != 0)))
+                                       continue;
 
                 /* If the path isn't set return the first one we find */
                if (path == NULL || strlen(path) == 0) {
                        strncpy(mntdir, mnt.mnt_dir, sizeof(mntdir) - 1);
                        mntdir[sizeof(mntdir) - 1] = '\0';
                        if ((want & WANT_FSNAME) && fsname != NULL) {
-                               strncpy(fsname, ptr, ptr_end - ptr);
-                               fsname[ptr_end - ptr] = '\0';
+                               strncpy(fsname, ptr, mountlen);
+                               fsname[mountlen] = '\0';
                        }
                        rc = 0;
                        break;
@@ -1316,8 +1319,8 @@ int get_root_path(int want, char *fsname, int *outfd, char *path, int index)
                        mntdir[sizeof(mntdir) - 1] = '\0';
                        len = mntlen;
                        if ((want & WANT_FSNAME) && fsname != NULL) {
-                               strncpy(fsname, ptr, ptr_end - ptr);
-                               fsname[ptr_end - ptr] = '\0';
+                               strncpy(fsname, ptr, mountlen);
+                               fsname[mountlen] = '\0';
                        }
                        rc = 0;
                }