Test case: /tmp$ mkdir -p 1/2 /tmp$ sudo mount -o size=1M -t tmpfs x 1/2 /tmp$ sudo mount -o size=2M -t tmpfs y 1 /tmp$ mkdir 1/2 /tmp$ df -h 1/2 Filesystem Size Used Avail Use% Mounted on x 2.0M 0 2.0M 0% /tmp/1/2
The Size is correct as that's obtained from statfs() on the file. But when it comes to finding the corresponding mount source and mountpoint, it fails. /tmp$ grep /tmp/ /proc/mounts x /tmp/1/2 tmpfs rw,relatime,size=1024k 0 0 y /tmp/1 tmpfs rw,relatime,size=2048k 0 0 df should walk /proc/self/mounts or /etc/mtab from the bottom up until it finds the first mount point that is a parent of the realpath of the file. /tmp$ df --version df (GNU coreutils) 8.28 (on Debian testing amd64) Related: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=15955 That's just been discussed on the austin group mailing list: https://www.mail-archive.com/[email protected]/msg01715.html https://www.mail-archive.com/[email protected]/msg01720.html Not critical as that could be considered as a pathological test case. -- Stephane
