From c72e9f343f3967fcb936e1131430a6853f1e1d33 Mon Sep 17 00:00:00 2001
From: Dave Chiluk <chiluk@canonical.com>
Date: Mon, 31 Aug 2015 16:07:58 -0500
Subject: [PATCH 1/2] mountlist: add me_mntroot field on Linux machines
* lib/mountlist.c (read_file_system_list): Populate me_mntroot in
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 differently than mountroot=/ mounts by the
kernel, but the user often wants these bind mounts distinguished.
* lib/mountlist.h (struct mount_entry): Add me_mntroot element.
More details at https://pad.lv/1432871
Upstream-commit: c6148bca89e9465fd6ba3a10d273ec4cb58c2dbe
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/mountlist.c | 25 ++++++++++++++++++++++---
lib/mountlist.h | 2 ++
2 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/lib/mountlist.c b/lib/mountlist.c
index 6f04f55..08ade6f 100644
--- a/lib/mountlist.c
+++ b/lib/mountlist.c
@@ -447,6 +447,7 @@ 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);
@@ -478,7 +479,8 @@ 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;
+ int source_s, source_e, mntroot_s, mntroot_e;
char test;
char *dash;
int rc;
@@ -486,13 +488,15 @@ 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 " - " */
@@ -511,16 +515,19 @@ 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 + target_s);
+ unescape_tab (line + mntroot_s);
me = xmalloc (sizeof *me);
me->me_devname = xstrdup (dash + source_s);
me->me_mountdir = xstrdup (line + target_s);
+ me->me_mntroot = xstrdup (line + mntroot_s);
me->me_type = xstrdup (dash + type_s);
me->me_type_malloced = 1;
me->me_dev = makedev (devmaj, devmin);
@@ -566,6 +573,7 @@ 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 +606,7 @@ 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 +633,7 @@ 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 +660,7 @@ 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 +759,7 @@ 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->me_mntroot = NULL;
me->me_type = xstrdup (fi.fsh_name);
me->me_type_malloced = 1;
me->me_dev = fi.dev;
@@ -797,6 +809,7 @@ 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 +846,7 @@ 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 +894,7 @@ 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 +957,7 @@ 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 +1036,7 @@ 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 +1080,7 @@ 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 +1123,7 @@ 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. */
--
2.5.5
From aff5e38d43f8477ccf07eb9e87a849b6c3211302 Mon Sep 17 00:00:00 2001
From: Dave Chiluk <chiluk@canonical.com>
Date: Mon, 21 Sep 2015 15:04:11 -0500
Subject: [PATCH 2/2] df: prioritize mounts nearer the device root
In the presence of bind mounts of a device, the 4th "mount root" field
from /proc/self/mountinfo is now considered, so as to prefer mount
points closer to the root of the device. Note on older systems with
an /etc/mtab file, the source device was listed as the originating
directory, and so this was not an issue.
Details at http://pad.lv/1432871
* src/df.c (filter_mount_list): When deduplicating mount entries,
only prefer sources nearer or at the root of the device, when the
target is nearer the root of the device.
* NEWS: Mention the change in behavior.
Upstream-commit: 3babaf83875ceac896c8dd3a64248e955dfecef9
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
src/df.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/df.c b/src/df.c
index 0dfd554..e390298 100644
--- a/src/df.c
+++ b/src/df.c
@@ -649,6 +649,13 @@ filter_mount_list (bool devices_only)
if (devlist)
{
+ bool target_nearer_root = strlen (devlist->me->me_mountdir)
+ > strlen (me->me_mountdir);
+ /* With bind mounts, prefer items nearer the root of the source */
+ bool source_below_root = devlist->me->me_mntroot != NULL
+ && me->me_mntroot != NULL
+ && (strlen (devlist->me->me_mntroot)
+ < strlen (me->me_mntroot));
if (! print_grand_total && me->me_remote && devlist->me->me_remote
&& ! STREQ (devlist->me->me_devname, me->me_devname))
{
@@ -660,9 +667,8 @@ filter_mount_list (bool devices_only)
else if ((strchr (me->me_devname, '/')
/* let "real" devices with '/' in the name win. */
&& ! strchr (devlist->me->me_devname, '/'))
- /* let a shorter mountdir win. */
- || (strlen (devlist->me->me_mountdir)
- > strlen (me->me_mountdir))
+ /* let points towards the root of the device win. */
+ || (target_nearer_root && ! source_below_root)
/* let an entry overmounted on a new device win... */
|| (! STREQ (devlist->me->me_devname, me->me_devname)
/* ... but only when matching an existing mnt point,
--
2.5.5