Linus Torvalds 143c97cc65 Revert "pty: fix the cached path of the pty slave file descriptor in the master" ... This reverts commit c8c03f1858. It turns out that while fixing the ptmx file descriptor to have the correct 'struct path' to the associated slave pty is a really good thing, it breaks some user space tools for a very annoying reason. The problem is that /dev/ptmx and its associated slave pty (/dev/pts/X) are on different mounts. That was what caused us to have the wrong path in the first place (we would mix up the vfsmount of the 'ptmx' node, with the dentry of the pty slave node), but it also means that now while we use the right vfsmount, having the pty master open also keeps the pts mount busy. And it turn sout that that makes 'pbuilder' very unhappy, as noted by Stefan Lippers-Hollmann: "This patch introduces a regression for me when using pbuilder 0.228.7[2] (a helper to build Debian packages in a chroot and to create and update its chroots) when trying to umount /dev/ptmx (inside the chroot) on Debian/ unstable (full log and pbuilder configuration file[3] attached). [...] Setting up build-essential (12.3) ... Processing triggers for libc-bin (2.24-15) ... I: unmounting dev/ptmx filesystem W: Could not unmount dev/ptmx: umount: /var/cache/pbuilder/build/1340/dev/ptmx: target is busy (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1).)" apparently pbuilder tries to unmount the /dev/pts filesystem while still holding at least one master node open, which is arguably not very nice, but we don't break user space even when fixing other bugs. So this commit has to be reverted. I'll try to figure out a way to avoid caching the path to the slave pty in the master pty. The only thing that actually wants that slave pty path is the "TIOCGPTPEER" ioctl, and I think we could just recreate the path at that time. Reported-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> Cc: Eric W Biederman <ebiederm@xmission.com> Cc: Christian Brauner <christian.brauner@canonical.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2017-08-23 18:16:11 -07:00
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acpi
asm-generic	mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem	2017-08-10 15:54:07 -07:00
clocksource
crypto
drm
dt-bindings
keys
kvm
linux	Revert "pty: fix the cached path of the pty slave file descriptor in the master"	2017-08-23 18:16:11 -07:00
math-emu
media
memory
misc
net	net_sched: fix order of queue length updates in qdisc_replace()	2017-08-20 20:02:00 -07:00
pcmcia
ras
rdma
rxrpc
scsi	SCSI fixes on 20170823	2017-08-23 11:34:40 -07:00
soc
sound
target	iscsi-target: Fix iscsi_np reset hung task during parallel delete	2017-08-06 14:41:41 -07:00
trace	ext4: remove unused metadata accounting variables	2017-07-30 22:30:11 -04:00
uapi	drm/msm: Remove __user from __u64 data types	2017-08-01 19:11:48 -04:00
video
xen