>From 6d926c16018d1406f7477c9e44bc0ed55bf09836 Mon Sep 17 00:00:00 2001 From: Dave Chiluk Date: Mon, 21 Sep 2015 15:04:11 -0500 Subject: [PATCH] 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. --- NEWS | 3 +++ src/df.c | 12 +++++++++--- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/NEWS b/NEWS index 63574da..9aec259 100644 --- a/NEWS +++ b/NEWS @@ -17,6 +17,9 @@ GNU coreutils NEWS -*- outline -*- base64 no longer supports hex or oct --wrap parameters, thus better supporting decimals with leading zeros. + df now prefers sources towards the root of a device when + eliding duplicate bind mounted entries. + ** Improvements du no longer stats all mount points at startup, only doing so diff --git a/src/df.c b/src/df.c index 2e541b9..7e7b2ba 100644 --- a/src/df.c +++ b/src/df.c @@ -641,6 +641,13 @@ 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 device */ + bool target_nearer_device_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)) { @@ -652,9 +659,8 @@ 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 && target_nearer_device_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, -- 2.5.0