linux/fs/autofs4
NeilBrown ecc0c469f2 autofs: don't fail mount for transient error
Currently if the autofs kernel module gets an error when writing to the
pipe which links to the daemon, then it marks the whole moutpoint as
catatonic, and it will stop working.

It is possible that the error is transient.  This can happen if the
daemon is slow and more than 16 requests queue up.  If a subsequent
process tries to queue a request, and is then signalled, the write to
the pipe will return -ERESTARTSYS and autofs will take that as total
failure.

So change the code to assess -ERESTARTSYS and -ENOMEM as transient
failures which only abort the current request, not the whole mountpoint.

It isn't a crash or a data corruption, but having autofs mountpoints
suddenly stop working is rather inconvenient.

Ian said:

: And given the problems with a half dozen (or so) user space applications
: consuming large amounts of CPU under heavy mount and umount activity this
: could happen more easily than we expect.

Link: http://lkml.kernel.org/r/87y3norvgp.fsf@notabene.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:02 -08:00
..
Kconfig Fix dead URLs to ftp.kernel.org 2017-03-28 16:16:52 +02:00
Makefile autofs4: add miscellaneous device for ioctls 2008-10-16 11:21:39 -07:00
autofs_i.h autofs: non functional header inclusion cleanup 2017-09-08 18:26:50 -07:00
dev-ioctl.c autofs: use unsigned int/long instead of uint/ulong for ioctl args 2017-09-08 18:26:50 -07:00
expire.c autofs - dont hold spin lock over direct mount expire 2016-12-03 20:51:50 -05:00
init.c autofs4: coding style fixes 2016-03-15 16:55:16 -07:00
inode.c don't open-code file_inode() 2016-12-04 18:29:28 -05:00
root.c autofs: take more care to not update last_used on path walk 2017-02-27 18:43:45 -08:00
symlink.c vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
waitq.c autofs: don't fail mount for transient error 2017-11-17 16:10:02 -08:00