linux-toradex.git/fs/autofs4, branch v4.4.135

autofs: mount point create should honour passed in mode

2018-04-24T07:32:11+00:00

commit 1e6306652ba18723015d1b4967fe9de55f042499 upstream.

The autofs file system mkdir inode operation blindly sets the created
directory mode to S_IFDIR | 0555, ingoring the passed in mode, which can
cause selinux dac_override denials.

But the function also checks if the caller is the daemon (as no-one else
should be able to do anything here) so there's no point in not honouring
the passed in mode, allowing the daemon to set appropriate mode when
required.

Link: http://lkml.kernel.org/r/152361593601.8051.14014139124905996173.stgit@pluto.themaw.net
Signed-off-by: Ian Kent 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

autofs: fix careless error in recent commit

2017-12-20T09:04:51+00:00

commit 302ec300ef8a545a7fc7f667e5fd743b091c2eeb upstream.

Commit ecc0c469f277 ("autofs: don't fail mount for transient error") was
meant to replace an 'if' with a 'switch', but instead added the 'switch'
leaving the case in place.

Link: http://lkml.kernel.org/r/87zi6wstmw.fsf@notabene.neil.brown.name
Fixes: ecc0c469f277 ("autofs: don't fail mount for transient error")
Reported-by: Ben Hutchings 
Signed-off-by: NeilBrown 
Cc: Ian Kent 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

autofs: don't fail mount for transient error

2017-11-30T08:37:20+00:00

commit ecc0c469f27765ed1e2b967be0aa17cee1a60b76 upstream.

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 
Acked-by: Ian Kent 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL

2017-06-29T10:48:50+00:00

commit 9fa4eb8e490a28de40964b1b0e583d8db4c7e57c upstream.

If a positive status is passed with the AUTOFS_DEV_IOCTL_FAIL ioctl,
autofs4_d_automount() will return

   ERR_PTR(status)

with that status to follow_automount(), which will then dereference an
invalid pointer.

So treat a positive status the same as zero, and map to ENOENT.

See comment in systemd src/core/automount.c::automount_send_ready().

Link: http://lkml.kernel.org/r/871sqwczx5.fsf@notabene.neil.brown.name
Signed-off-by: NeilBrown 
Cc: Ian Kent 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

autofs: use dentry flags to block walks during expire

2016-09-30T08:18:37+00:00

commit 7cbdb4a286a60c5d519cb9223fe2134d26870d39 upstream.

Somewhere along the way the autofs expire operation has changed to hold
a spin lock over expired dentry selection.  The autofs indirect mount
expired dentry selection is complicated and quite lengthy so it isn't
appropriate to hold a spin lock over the operation.

Commit 47be61845c77 ("fs/dcache.c: avoid soft-lockup in dput()") added a
might_sleep() to dput() causing a WARN_ONCE() about this usage to be
issued.

But the spin lock doesn't need to be held over this check, the autofs
dentry info.  flags are enough to block walks into dentrys during the
expire.

I've left the direct mount expire as it is (for now) because it is much
simpler and quicker than the indirect mount expire and adding spin lock
release and re-aquires would do nothing more than add overhead.

Fixes: 47be61845c77 ("fs/dcache.c: avoid soft-lockup in dput()")
Link: http://lkml.kernel.org/r/20160912014017.1773.73060.stgit@pluto.themaw.net
Signed-off-by: Ian Kent 
Reported-by: Takashi Iwai 
Tested-by: Takashi Iwai 
Cc: Takashi Iwai 
Cc: NeilBrown 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

autofs races

2016-09-30T08:18:37+00:00

commit ea01a18494b3d7a91b2f1f2a6a5aaef4741bc294 upstream.

* make autofs4_expire_indirect() skip the dentries being in process of
expiry
* do *not* mess with list_move(); making sure that dentry with
AUTOFS_INF_EXPIRING are not picked for expiry is enough.
* do not remove NO_RCU when we set EXPIRING, don't bother with smp_mb()
there.  Clear it at the same time we clear EXPIRING.  Makes a bunch of
tests simpler.
* rename NO_RCU to WANT_EXPIRE, which is what it really is.

Signed-off-by: Al Viro 
Cc: Ian Kent 
Signed-off-by: Greg Kroah-Hartman

make simple_positive() public

2015-06-23T22:02:01+00:00

Signed-off-by: Al Viro

don't pass nameidata to ->follow_link()

2015-05-11T02:20:15+00:00

its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro

new ->follow_link() and ->put_link() calling conventions

2015-05-11T02:19:45+00:00

a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.

Signed-off-by: Al Viro

VFS: normal filesystems (and lustre): d_inode() annotations

2015-04-15T19:06:57+00:00

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells 
Signed-off-by: Al Viro