24 Jun, 2015
1 commit
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Signed-off-by: Al Viro
11 May, 2015
2 commits
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its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidataSigned-off-by: Al Viro
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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
16 Apr, 2015
1 commit
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that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells
Signed-off-by: Al Viro
12 Apr, 2015
1 commit
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Signed-off-by: Al Viro
23 Feb, 2015
2 commits
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X-Coverup: just ask spender
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro -
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($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
die "Can't grep for S_ISDIR and co. callers";
@callers = ;
close($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
Signed-off-by: Al Viro
20 Feb, 2015
1 commit
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%pD for struct file*, %pd for struct dentry*.
Fixes: a455589f181e ("assorted conversions to %p[dD]")
Signed-off-by: Rasmus Villemoes
Signed-off-by: Al Viro
20 Nov, 2014
1 commit
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Signed-off-by: Al Viro
04 Nov, 2014
1 commit
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Signed-off-by: Al Viro
14 Oct, 2014
5 commits
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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
Reviewed-by: Ian Kent
Tested-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
->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
Reviewed-by: Ian Kent
Tested-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Reviewed-by: Ian Kent
Tested-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Future patch will potentially call this twice, so make it separate.
Signed-off-by: NeilBrown
Reviewed-by: Ian Kent
Tested-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Reviewed-by: Ian Kent
Tested-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Oct, 2014
1 commit
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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
Cc: Al Viro
Cc: Eric W. Biederman
Signed-off-by: Al Viro
09 Aug, 2014
5 commits
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Signed-off-by: NeilBrown
Acked-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
{__,}manage_dentry_{set,clear}_{automount,transit}
are 4 unused inline functions. Discard them.
Signed-off-by: NeilBrown
Acked-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Reviewed-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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 b5b801779d59 ("autofs4: Add d_manage()
dentry operation").Signed-off-by: NeilBrown
Acked-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: NeilBrown
Acked-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2014
1 commit
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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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Jun, 2014
1 commit
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autofs_dev_ioctl_init is only called by __init init_autofs4_fs
Signed-off-by: Fabian Frederick
Acked-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 May, 2014
1 commit
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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
Cc: Al Viro
Cc: Linus Torvalds
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Apr, 2014
1 commit
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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
Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Jan, 2014
5 commits
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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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the helper macro !IS_ROOT to replace parent != dentry->d_parent. Just
clean up.Signed-off-by: Rui Xiang
Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Serge Hallyn
Cc: Eric Biederman
Acked-by: Ian Kent
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Miklos Szeredi
Acked-by: Serge Hallyn
Cc: Eric Biederman
Acked-by: Ian Kent
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Oct, 2013
2 commits
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makes ->d_managed() safety in RCU mode independent from vfsmount_lock
Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
17 Sep, 2013
1 commit
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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
Acked-by: Ian Kent
09 Sep, 2013
1 commit
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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
Cc: Jeff Layton
Cc: Al Viro
Signed-off-by: Al Viro
05 Jul, 2013
1 commit
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Signed-off-by: Al Viro
29 Jun, 2013
1 commit
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new helpers - dir_emit_dot(file, ctx, dentry), dir_emit_dotdot(file, ctx),
dir_emit_dots(file, ctx).Signed-off-by: Al Viro
07 May, 2013
2 commits
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When checking if an autofs mount point is busy it isn't sufficient to
only check if it's a mount point.For example, if the mount of an offset mountpoint in a tree is denied
for this host by its export and the dentry becomes a process working
directory the check incorrectly returns the mount as not in use at
expire.This can happen since the default when mounting within a tree is
nostrict, which means ingnore mount fails on mounts within the tree and
continue. The nostrict option is meant to allow mounting in this case.Signed-off-by: David Jeffery
Signed-off-by: Ian Kent
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds -
Fixed the sparse warning:
fs/autofs4/root.c:411:5: warning: symbol 'autofs4_d_manage' was not declared. Should it be static?"
[ Clearly it should be static as the function is declared static at the
top of root.c. - imk ]Signed-off-by: Claudiu Ghioc
Signed-off-by: Ian Kent
Signed-off-by: Linus Torvalds
04 Mar, 2013
1 commit
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Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.Acked-by: Serge Hallyn
Acked-by: Kees Cook
Reported-by: Kees Cook
Signed-off-by: "Eric W. Biederman"
02 Mar, 2013
1 commit
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smatch analysis:
fs/autofs4/waitq.c:46 autofs4_catatonic_mode() info: redundant null check on wq->name.name calling kfree()
Signed-off-by: Tim Gardner
Signed-off-by: Ian Kent
Cc: autofs@vger.kernel.org
Signed-off-by: Linus Torvalds
