Commit Graph

283 Commits

Author SHA1 Message Date
Andrey Vagin
5a9294e5c5 autofs: don't get stuck in a loop if vfs_write() returns an error
__vfs_write() returns a negative value in a error case.

Link: http://lkml.kernel.org/r/20160616083108.6278.65815.stgit@pluto.themaw.net
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 17:23:52 -07:00
Al Viro
ea01a18494 autofs races
* 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 <viro@zeniv.linux.org.uk>
2016-06-12 11:24:46 -04:00
Al Viro
4e82901cd6 dcache_{readdir,dir_lseek}() users: switch to ->iterate_shared
no need to lock directory in dcache_dir_lseek(), while we are
at it - per-struct file exclusion is enough.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:32 -04:00
Linus Torvalds
3c2de27d79 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:

 - Preparations of parallel lookups (the remaining main obstacle is the
   need to move security_d_instantiate(); once that becomes safe, the
   rest will be a matter of rather short series local to fs/*.c

 - preadv2/pwritev2 series from Christoph

 - assorted fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
  splice: handle zero nr_pages in splice_to_pipe()
  vfs: show_vfsstat: do not ignore errors from show_devname method
  dcache.c: new helper: __d_add()
  don't bother with __d_instantiate(dentry, NULL)
  untangle fsnotify_d_instantiate() a bit
  uninline d_add()
  replace d_add_unique() with saner primitive
  quota: use lookup_one_len_unlocked()
  cifs_get_root(): use lookup_one_len_unlocked()
  nfs_lookup: don't bother with d_instantiate(dentry, NULL)
  kill dentry_unhash()
  ceph_fill_trace(): don't bother with d_instantiate(dn, NULL)
  autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
  configfs: move d_rehash() into configfs_create() for regular files
  ceph: don't bother with d_rehash() in splice_dentry()
  namei: teach lookup_slow() to skip revalidate
  namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()
  lookup_one_len_unlocked(): use lookup_dcache()
  namei: simplify invalidation logics in lookup_dcache()
  namei: change calling conventions for lookup_{fast,slow} and follow_managed()
  ...
2016-03-19 18:52:29 -07:00
Ian Kent
8a78d59304 autofs4: use pr_xxx() macros directly for logging
Use the standard pr_xxx() log macros directly for log prints instead of
the AUTOFS_XXX() macros.

Signed-off-by: Ian Kent <ikent@redhat.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
90967c87e3 autofs4: change log print macros to not insert newline
Common kernel coding practice is to include the newline of log prints
within the log text rather than hidden away in a macro.

To avoid introducing inconsistencies as changes are made change the log
macros to not include the newline.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
cab49f9ed8 autofs4: make autofs log prints consistent
Use the pr_*() print in AUTOFS_*() macros instead of printks and include
the module name in log message macros.  Also use the AUTOFS_*() macros
everywhere instead of raw printks.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
0266725ad4 autofs4: fix some white space errors
Fix some white space format errors.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
e3cd8067c1 autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()
The return from an ioctl if an invalid ioctl is passed in should be
EINVAL not ENOSYS.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
b3f67a988c autofs4: fix coding style line length in autofs4_wait()
The need for this is questionable but checkpatch.pl complains about the
line length and it's a straightfoward change.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
aa330ddc53 autofs4: fix coding style problem in autofs4_get_set_timeout()
Refactor autofs4_get_set_timeout() to eliminate coding style error.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
e9a7c2f1a5 autofs4: coding style fixes
Try and make the coding style completely consistent throughtout the
autofs module and inline with kernel coding style recommendations.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Stanislav Kinsburskiy
c83aa55d0b autofs: show pipe inode in mount options
This is required for CRIU (Checkpoint Restart In Userspace) to migrate a
mount point when write end in user space is closed.

Below is a brief description of the problem.

To migrate a non-catatonic autofs mount point, one has to restore the
control pipe between kernel and autofs master process.

One of the autofs masters is systemd, which closes pipe write end after
passing it to the kernel with mount call.

To be able to restore the systemd control pipe one has to know which
read pipe end in systemd corresponds to the write pipe end in the
kernel.  The pipe "fd" in mount options is not enough because it was
closed and probably replaced by some other descriptor.

Thus, some other attribute is required to be able to find the read pipe
end.  The best attribute to use to find the correct pipe end is inode
number becuase it's unique for the whole system and can't be reused
while the autofs mount exists.

This attribute can also be used to recognize a situation where an autofs
mount has no master (no process with specified "pgrp" or no file
descriptor with "pipe_ino", specified in autofs mount options).

Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Al Viro
de4acda16e autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-14 00:16:00 -04:00
Al Viro
fceef393a5 switch ->get_link() to delayed_call, kill ->put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-30 13:01:03 -05:00
Al Viro
6b2553918d replace ->follow_link() with new method that could stay in RCU mode
new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 22:41:54 -05:00
Al Viro
dc3f4198ea make simple_positive() public
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:02:01 -04:00
Al Viro
6e77137b36 don't pass nameidata to ->follow_link()
its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:20:15 -04:00
Al Viro
680baacbca new ->follow_link() and ->put_link() calling conventions
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 <viro@zeniv.linux.org.uk>
2015-05-10 22:19:45 -04:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Al Viro
a35fb914ae autofs: switch to __vfs_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:37 -04:00
Al Viro
0a280962dc autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation
X-Coverup: just ask spender
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:43:34 -05:00
David Howells
e36cb0b89c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
Convert the following where appropriate:

 (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).

 (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).

 (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry).  This is actually more
     complicated than it appears as some calls should be converted to
     d_can_lookup() instead.  The difference is whether the directory in
     question is a real dir with a ->lookup op or whether it's a fake dir with
     a ->d_automount op.

In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).

Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer.  In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.

However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.

There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE.  Strictly, this was
intended for special directory entry types that don't have attached inodes.

The following perl+coccinelle script was used:

use strict;

my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
    die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
    print "No matches\n";
    exit(0);
}

my @cocci = (
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISLNK(E->d_inode->i_mode)',
    '+ d_is_symlink(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISDIR(E->d_inode->i_mode)',
    '+ d_is_dir(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISREG(E->d_inode->i_mode)',
    '+ d_is_reg(E)' );

my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);

foreach my $file (@callers) {
    chomp $file;
    print "Processing ", $file, "\n";
    system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
	die "spatch failed";
}

[AV: overlayfs parts skipped]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:38:41 -05:00
Rasmus Villemoes
76bf3f6b1d autofs4: Wrong format for printing dentry
%pD for struct file*, %pd for struct dentry*.

Fixes: a455589f18 ("assorted conversions to %p[dD]")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-20 04:56:45 -05:00
Al Viro
a455589f18 assorted conversions to %p[dD]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:01:20 -05:00
Al Viro
946e51f2bf move d_rcu from overlapping d_child to overlapping d_alias
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-03 15:20:29 -05:00
NeilBrown
ef16cc5909 autofs4: d_manage() should return -EISDIR when appropriate in rcu-walk mode.
If rcu-walk mode we don't *have* to return -EISDIR for non-mount-traps
as we will simply drop into REF-walk and handling DCACHE_NEED_AUTOMOUNT
dentrys the slow way.  But it is better if we do when possible.

In 'oz_mode', use the same condition as ref-walk: if not a mountpoint,
then it must be -EISDIR.

In regular mode there are most tests needed.  Most of them can be
performed without taking any spinlocks.  If we find a directory that
isn't obviously empty, and isn't mounted on, we need to call
'simple_empty()' which does take a spinlock.  If this turned out to hurt
performance, some other approach could be found to signal when a
directory is known to be empty.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Ian Kent <raven@themaw.net>
Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:16 +02:00
NeilBrown
4d885f90e3 autofs4: avoid taking fs_lock during rcu-walk
->fs_lock protects AUTOFS_INF_EXPIRING.  We need to be sure that once
the flag is set, no new references beneath the dentry are taken.  So
rcu-walk currently needs to take fs_lock before checking the flag.  This
hurts performance.

Change the expiry to a two-stage process.  First set AUTOFS_INF_NO_RCU
which forces any path walk into ref-walk mode, then drop the lock and
call synchronize_rcu().  Once that returns we can be sure no rcu-walk is
active beneath the dentry and we can check reference counts again.

Now during an RCU-walk we can test AUTOFS_INF_EXPIRING without taking
the lock as along as we test AUTOFS_INF_NO_RCU too.  If either are set,
we must abort the RCU-walk If neither are set, we know that refcounts
will be tested again after we finish the RCU-walk so we are safe to
continue.

->fs_lock is still taken in d_manage() to check for a non-trap
directory.  That will be resolved in the next patch.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Ian Kent <raven@themaw.net>
Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:16 +02:00
NeilBrown
6ece08e618 autofs4: make "autofs4_can_expire" idempotent.
Have a "test" function change the value it is testing can be confusing,
particularly as a future patch will be calling this function twice.

So move the update for 'last_used' to avoid repeat expiry to the place
where the final determination on what to expire is known.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Ian Kent <raven@themaw.net>
Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:16 +02:00
NeilBrown
a5d1dba143 autofs4: factor should_expire() out of autofs4_expire_indirect.
Future patch will potentially call this twice, so make it separate.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Ian Kent <raven@themaw.net>
Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:16 +02:00
NeilBrown
23bfc2a24e autofs4: allow RCU-walk to walk through autofs4
This series teaches autofs about RCU-walk so that we don't drop straight
into REF-walk when we hit an autofs directory, and so that we avoid
spinlocks as much as possible when performing an RCU-walk.

This is needed so that the benefits of the recent NFS support for
RCU-walk are fully available when NFS filesystems are automounted.

Patches have been carefully reviewed and tested both with test suites
and in production - thanks a lot to Ian Kent for his support there.

This patch (of 6):

Any attempt to look up a pathname that passes though an autofs4 mount is
currently forced out of RCU-walk into REF-walk.

This can significantly hurt performance of many-thread work loads on
many-core systems, especially if the automounted filesystem supports
RCU-walk but doesn't get to benefit from it.

So if autofs4_d_manage is called with rcu_walk set, only fail with -ECHILD
if it is necessary to wait longer than a spinlock.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Ian Kent <raven@themaw.net>
Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:16 +02:00
Ian Kent
b3ca406f27 autofs - remove obsolete d_invalidate() from expire
Biederman's umount-on-rmdir series changes d_invalidate() to sumarily remove
mounts under the passed in dentry regardless of whether they are busy
or not. So calling this in fs/autofs4/expire.c:autofs4_tree_busy() is
definitely the wrong thing to do becuase it will silently umount entries
instead of just cleaning stale dentrys.

But this call shouldn't be needed and testing shows that automounting
continues to function without it.

As Al Viro correctly surmises the original intent of the call was to
perform what shrink_dcache_parent() does.

If at some time in the future I see stale dentries accumulating
following failed mounts I'll revisit the issue and possibly add a
shrink_dcache_parent() call if needed.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:38:52 -04:00
NeilBrown
3b97dd0581 autofs4: comment typo: remove a a doubled word
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:19 -07:00
NeilBrown
bdac38329e autofs4: remove some unused inline functions
{__,}manage_dentry_{set,clear}_{automount,transit}

are 4 unused inline functions.  Discard them.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:19 -07:00
NeilBrown
668128e90b autofs4: don't take spinlock when not needed in autofs4_lookup_expiring
If the expiring_list is empty, we can avoid a costly spinlock in the
rcu-walk path through autofs4_d_manage (once the rest of the path
becomes rcu-walk friendly).

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:19 -07:00
NeilBrown
c312442fe3 autofs4: remove a redundant assignment
The variable 'ino' already exists and already has the correct value.
The d_fsdata of a dentry is never changed after the d_fsdata is
instantiated, so this new assignment cannot be necessary.

It was introduced in commit b5b801779d ("autofs4: Add d_manage()
dentry operation").

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:19 -07:00
NeilBrown
26b7a54a35 autofs4: remove unused autofs4_ispending()
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:18 -07:00
Ian Kent
571ff4731b autofs4: fix false positive compile error
On strict build environments we can see:

  fs/autofs4/inode.c: In function 'autofs4_fill_super':
  fs/autofs4/inode.c:312: error: 'pgrp' may be used uninitialized in this function
  make[2]: *** [fs/autofs4/inode.o] Error 1
  make[1]: *** [fs/autofs4] Error 2
  make: *** [fs] Error 2
  make: *** Waiting for unfinished jobs....

This is due to the use of pgrp_set being used to indicate pgrp has has
been set rather than initializing pgrp itself.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-03 09:21:53 -07:00
Fabian Frederick
3ff6db3287 fs/autofs4/dev-ioctl.c: add __init to autofs_dev_ioctl_init
autofs_dev_ioctl_init is only called by __init init_autofs4_fs

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:21 -07:00
Ian Kent
6b6751f7fe autofs: fix lockref lookup
autofs needs to be able to see private data dentry flags for its dentrys
that are being created but not yet hashed and for its dentrys that have
been rmdir()ed but not yet freed.  It needs to do this so it can block
processes in these states until a status has been returned to indicate
the given operation is complete.

It does this by keeping two lists, active and expring, of dentrys in
this state and uses ->d_release() to keep them stable while it checks
the reference count to determine if they should be used.

But with the recent lockref changes dentrys being freed sometimes don't
transition to a reference count of 0 before being freed so autofs can
occassionally use a dentry that is invalid which can lead to a panic.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:59 -07:00
Sasha Levin
e53d77eb8b autofs4: check dev ioctl size before allocating
There wasn't any check of the size passed from userspace before trying
to allocate the memory required.

This meant that userspace might request more space than allowed,
triggering an OOM.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 16:48:51 -07:00
Ian Kent
8dc51fe5ab autofs: fix symlinks aren't checked for expiry
The autofs4 module doesn't consider symlinks for expire as it did in the
older autofs v3 module (so it's actually a long standing regression).

The user space daemon has focused on the use of bind mounts instead of
symlinks for a long time now and that's why this has not been noticed.
But with the future addition of amd map parsing to automount(8), not to
mention amd itself (of am-utils), symlink expiry will be needed.

The direct and offset mount types can't be symlinks and the tree mounts of
version 4 were always real mounts so only indirect mounts need expire
symlinks.

Since the current users of the autofs4 module haven't reported this as a
problem to date this patch probably isn't a candidate for backport to
stable.

Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:59 -08:00
Rui Xiang
c24930a9bb autofs: use IS_ROOT to replace root dentry checks
Use the helper macro !IS_ROOT to replace parent != dentry->d_parent.  Just
clean up.

Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:59 -08:00
Rui Xiang
da29b75439 autofs: fix the return value of autofs4_fill_super
While kzallocing sbi/ino fails, it should return -ENOMEM.

And it should return the err value from autofs_prepare_pipe.

Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:59 -08:00
Miklos Szeredi
fbff08706d autofs4: translate pids to the right namespace for the daemon
The PID and the TGID of the process triggering the mount are sent to the
daemon.  Currently the global pid values are sent (ones valid in the
initial pid namespace) but this is wrong if the autofs daemon itself is
not running in the initial pid namespace.

So send the pid values that are valid in the namespace of the autofs
daemon.

The namespace to use is taken from the oz_pgrp pid pointer, which was
set at mount time to the mounting process' pid namespace.

If the pid translation fails (the triggering process is in an unrelated
pid namespace) then the automount fails with ENOENT.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:59 -08:00
Sukadev Bhattiprolu
6eaba35b43 autofs4: allow autofs to work outside the initial PID namespace
Enable autofs4 to work in a "container".  oz_pgrp is converted from
pid_t to struct pid and this is stored at mount time based on the
"pgrp=" option or if the option is missing then the current pgrp.

The "pgrp=" option is interpreted in the PID namespace of the current
process.  This option is flawed in that it doesn't carry the namespace
information, so it should be deprecated.  AFAICS the autofs daemon
always sends the current pgrp, which is the default anyway.

The oz_pgrp is also set from the AUTOFS_DEV_IOCTL_SETPIPEFD_CMD ioctl.
This ioctl sets oz_pgrp to the current pgrp.  It is not allowed to
change the pid namespace.

oz_pgrp is used mainly to determine whether the process traversing the
autofs mount tree is the autofs daemon itself or not.  This function now
compares the pid pointers instead of the pid_t values.

One other use of oz_pgrp is in autofs4_show_options.  There is shows the
virtual pid number (i.e.  the one that is valid inside the PID namespace
of the calling process)

For debugging printk convert oz_pgrp to the value in the initial pid
namespace.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:58 -08:00
Al Viro
baa40671d3 autofs4: make freeing sbi rcu-delayed
makes ->d_managed() safety in RCU mode independent from vfsmount_lock

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:43:27 -04:00
Al Viro
72c2d53192 file->f_op is never NULL...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:54 -04:00
Al Viro
606035e76e autofs4: close the races around autofs4_notify_daemon()
Don't drop ->wq_mutex before calling autofs4_notify_daemon() only to regain it
there.  Besides being pointless, that opens a race window where autofs4_wait_release()
could've come and freed wq->name.name.  And do the debugging printk in the "reused an
existing wq" case before dropping ->wq_mutex - the same reason...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Ian Kent <raven@themaw.net>
2013-09-16 19:16:38 -04:00
Ian Kent
ac83871996 autofs4 - fix device ioctl mount lookup
When reconnecting to automounts at startup an autofs ioctl is used
to find the device and inode of existing mounts so they can be used
to open a file descriptor of possibly covered mounts.

At this time the the caller might not yet "own" the mount so it can
trigger calling ->d_automount(). This causes automount to hang when
trying to reconnect to direct or offset mount types.

Consequently kern_path() can't be used but kern_path_mountpoint() can be.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-08 22:07:47 -04:00