Add me_mountroot to mount_entry so linux machines based on /proc/self/mountinfo can distinguish between bind mounts and original mounts. In reality bind mounts aren't treated any different than mountroot=/ mounts by the kernel, but this is still confusing to the user, and a change in behavior
More information is available here https://bugs.launchpad.net/ubuntu/+source/coreutils/+bug/1432871 --- lib/mountlist.c | 24 +++++++++++++++++++++--- lib/mountlist.h | 2 ++ 2 files changed, 23 insertions(+), 3 deletions(-) diff --git a/lib/mountlist.c b/lib/mountlist.c index 6f04f55..f4463ff 100644 --- a/lib/mountlist.c +++ b/lib/mountlist.c @@ -478,7 +478,8 @@ read_file_system_list (bool need_fs_type) while (getline (&line, &buf_size, fp) != -1) { unsigned int devmaj, devmin; - int target_s, target_e, type_s, type_e, source_s, source_e; + int target_s, target_e, type_s, type_e, source_s, source_e, \ + mntroot_s, mntroot_e; char test; char *dash; int rc; @@ -486,13 +487,15 @@ read_file_system_list (bool need_fs_type) rc = sscanf(line, "%*u " /* id - discarded */ "%*u " /* parent - discarded */ "%u:%u " /* dev major:minor */ - "%*s " /* mountroot - discarded */ + "%n%*s%n " /* mountroot */ "%n%*s%n" /* target, start and end */ "%c", /* more data... */ &devmaj, &devmin, + &mntroot_s, &mntroot_e, &target_s, &target_e, &test); - if (rc != 3 && rc != 5) /* 5 if %n included in count. */ + + if (rc != 3 && rc != 7) /* 7 if %n included in count. */ continue; /* skip optional fields, terminated by " - " */ @@ -511,14 +514,17 @@ read_file_system_list (bool need_fs_type) continue; /* manipulate the sub-strings in place. */ + line[mntroot_e] = '\0'; line[target_e] = '\0'; dash[type_e] = '\0'; dash[source_e] = '\0'; unescape_tab (dash + source_s); + unescape_tab (line + mntroot_s); unescape_tab (line + target_s); me = xmalloc (sizeof *me); + me->me_mntroot = xstrdup (line + mntroot_s); me->me_devname = xstrdup (dash + source_s); me->me_mountdir = xstrdup (line + target_s); me->me_type = xstrdup (dash + type_s); @@ -566,6 +572,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (mnt->mnt_fsname); me->me_mountdir = xstrdup (mnt->mnt_dir); + me->me_mntroot = NULL; me->me_type = xstrdup (mnt->mnt_type); me->me_type_malloced = 1; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type, bind); @@ -598,6 +605,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (fsp->f_mntfromname); me->me_mountdir = xstrdup (fsp->f_mntonname); + me->me_mntroot = NULL; me->me_type = fs_type; me->me_type_malloced = 0; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type); @@ -624,6 +632,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (fsp->f_mntfromname); me->me_mountdir = xstrdup (fsp->f_mntonname); + me->me_mntroot = NULL; me->me_type = xstrdup (fsp->f_fstypename); me->me_type_malloced = 1; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type); @@ -650,6 +659,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (fsd.fd_req.devname); me->me_mountdir = xstrdup (fsd.fd_req.path); + me->me_mntroot = NULL; me->me_type = gt_names[fsd.fd_req.fstype]; me->me_type_malloced = 0; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type); @@ -748,6 +758,7 @@ read_file_system_list (bool need_fs_type) me->me_devname = xstrdup (fi.device_name[0] != '\0' ? fi.device_name : fi.fsh_name); me->me_mountdir = xstrdup (re != NULL ? re->name : fi.fsh_name); + me->mntroot = NULL ; me->me_type = xstrdup (fi.fsh_name); me->me_type_malloced = 1; me->me_dev = fi.dev; @@ -797,6 +808,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (stats[counter].f_mntfromname); me->me_mountdir = xstrdup (stats[counter].f_mntonname); + me->me_mntroot = NULL; me->me_type = xstrdup (FS_TYPE (stats[counter])); me->me_type_malloced = 1; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type); @@ -833,6 +845,7 @@ read_file_system_list (bool need_fs_type) strcpy (me->me_devname + 5, mnt.mt_dev); # endif me->me_mountdir = xstrdup (mnt.mt_filsys); + me->me_mntroot = NULL; me->me_dev = (dev_t) -1; /* Magic; means not known yet. */ me->me_type = ""; me->me_type_malloced = 0; @@ -880,6 +893,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup ((*ent)->mt_resource); me->me_mountdir = xstrdup ((*ent)->mt_directory); + me->me_mntroot = NULL; me->me_type = xstrdup ((*ent)->mt_fstype); me->me_type_malloced = 1; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type); @@ -942,6 +956,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (mnt.mnt_special); me->me_mountdir = xstrdup (mnt.mnt_mountp); + me->me_mntroot = NULL; me->me_type = xstrdup (mnt.mnt_fstype); me->me_type_malloced = 1; me->me_dummy = MNT_IGNORE (&mnt) != 0; @@ -1020,6 +1035,7 @@ read_file_system_list (bool need_fs_type) vmp->vmt_data[VMT_OBJECT].vmt_off); } me->me_mountdir = xstrdup (thisent + vmp->vmt_data[VMT_STUB].vmt_off); + me->me_mntroot = NULL; me->me_type = xstrdup (fstype_to_string (vmp->vmt_gfstype)); me->me_type_malloced = 1; options = thisent + vmp->vmt_data[VMT_ARGS].vmt_off; @@ -1063,6 +1079,7 @@ read_file_system_list (bool need_fs_type) me = xmalloc (sizeof *me); me->me_devname = xstrdup (dev.f_mntfromname); me->me_mountdir = xstrdup (dev.f_mntonname); + me->me_mntroot = NULL; me->me_type = xstrdup (dev.f_fstypename); me->me_type_malloced = 1; me->me_dummy = ME_DUMMY (me->me_devname, me->me_type); @@ -1105,6 +1122,7 @@ void free_mount_entry (struct mount_entry *me) { free (me->me_devname); free (me->me_mountdir); + free (me->me_mntroot); if (me->me_type_malloced) free (me->me_type); free (me); diff --git a/lib/mountlist.h b/lib/mountlist.h index 735776b..9ce3137 100644 --- a/lib/mountlist.h +++ b/lib/mountlist.h @@ -27,6 +27,8 @@ struct mount_entry { char *me_devname; /* Device node name, including "/dev/". */ char *me_mountdir; /* Mount point directory name. */ + char *me_mntroot; /* Directory on filesystem of device used */ + /* as root for the (bind) mount. */ char *me_type; /* "nfs", "4.2", etc. */ dev_t me_dev; /* Device number of me_mountdir. */ unsigned int me_dummy : 1; /* Nonzero for dummy file systems. */ -- 1.9.1
