All nfsd security depends on the security checks in fh_verify, and
especially on nfsd_setuser().
It therefore bothers me that the nfsd_setuser call may be made from
three different places, depending on whether the filehandle has already
been mapped to a dentry, and on whether subtreechecking is in force.
Instead, make an unconditional call in fh_verify(), so it's trivial to
verify that the call always occurs.
That leaves us with a redundant nfsd_setuser() call in the subtreecheck
case--it needs the correct user set earlier in order to check execute
permissions on the path to this filehandle--but I'm willing to accept
that minor inefficiency in the subtreecheck case in return for more
straightforward permission checking.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
None of this stuff is used outside nfsd, so move it out of the common
linux include directory.
Actually, probably none of the stuff in include/linux/nfsd/nfsd.h really
belongs there, so later we may remove that file entirely.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
A number of callers (nfsd4_encode_fattr(), at least) don't bother to
release the filehandle returned to fh_compose() if fh_compose() returns
an error. So, modify fh_compose() to release the filehandle before
returning an error.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The file nfsfh.c contains two static variables nfsd_nr_verified and
nfsd_nr_put. These are counters which are incremented as a side
effect of the fh_verify() fh_compose() and fh_put() operations,
i.e. at least twice per NFS call for any non-trivial workload.
Needless to say this makes the cacheline that contains them (and any
other innocent victims) a very hot contention point indeed under high
call-rate workloads on multiprocessor NFS server. It also turns out
that these counters are not used anywhere. They're not reported to
userspace, they're not used in logic, they're not even exported from
the object file (let alone the module). All they do is waste CPU time.
So this patch removes them.
Tests on a 16 CPU Altix A4700 with 2 10gige Myricom cards, configured
separately (no bonding). Workload is 640 client threads doing directory
traverals with random small reads, from server RAM.
Before
======
Kernel profile:
% cumulative self self total
time samples samples calls 1/call 1/call name
6.05 2716.00 2716.00 30406 0.09 1.02 svc_process
4.44 4706.00 1990.00 1975 1.01 1.01 spin_unlock_irqrestore
3.72 6376.00 1670.00 1666 1.00 1.00 svc_export_put
3.41 7907.00 1531.00 1786 0.86 1.02 nfsd_ofcache_lookup
3.25 9363.00 1456.00 10965 0.13 1.01 nfsd_dispatch
3.10 10752.00 1389.00 1376 1.01 1.01 nfsd_cache_lookup
2.57 11907.00 1155.00 4517 0.26 1.03 svc_tcp_recvfrom
...
2.21 15352.00 1003.00 1081 0.93 1.00 nfsd_choose_ofc <----
^^^^
Here the function nfsd_choose_ofc() reads a global variable
which by accident happened to be located in the same cacheline as
nfsd_nr_verified.
Call rate:
nullarbor:~ # pmdumptext nfs3.server.calls
...
Thu Dec 13 00:15:27 184780.663
Thu Dec 13 00:15:28 184885.881
Thu Dec 13 00:15:29 184449.215
Thu Dec 13 00:15:30 184971.058
Thu Dec 13 00:15:31 185036.052
Thu Dec 13 00:15:32 185250.475
Thu Dec 13 00:15:33 184481.319
Thu Dec 13 00:15:34 185225.737
Thu Dec 13 00:15:35 185408.018
Thu Dec 13 00:15:36 185335.764
After
=====
kernel profile:
% cumulative self self total
time samples samples calls 1/call 1/call name
6.33 2813.00 2813.00 29979 0.09 1.01 svc_process
4.66 4883.00 2070.00 2065 1.00 1.00 spin_unlock_irqrestore
4.06 6687.00 1804.00 2182 0.83 1.00 nfsd_ofcache_lookup
3.20 8110.00 1423.00 10932 0.13 1.00 nfsd_dispatch
3.03 9456.00 1346.00 1343 1.00 1.00 nfsd_cache_lookup
2.62 10622.00 1166.00 4645 0.25 1.01 svc_tcp_recvfrom
[...]
0.10 42586.00 44.00 74 0.59 1.00 nfsd_choose_ofc <--- HA!!
^^^^
Call rate:
nullarbor:~ # pmdumptext nfs3.server.calls
...
Thu Dec 13 01:45:28 194677.118
Thu Dec 13 01:45:29 193932.692
Thu Dec 13 01:45:30 194294.364
Thu Dec 13 01:45:31 194971.276
Thu Dec 13 01:45:32 194111.207
Thu Dec 13 01:45:33 194999.635
Thu Dec 13 01:45:34 195312.594
Thu Dec 13 01:45:35 195707.293
Thu Dec 13 01:45:36 194610.353
Thu Dec 13 01:45:37 195913.662
Thu Dec 13 01:45:38 194808.675
i.e. about a 5.3% improvement in call rate.
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Reviewed-by: David Chinner <dgc@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
When determining the fsid_type in fh_compose(), the setting of the FID
via fsid= export option needs to take precedence over using the UUID
device id.
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Inaugurate copy-on-write credentials management. This uses RCU to manage the
credentials pointer in the task_struct with respect to accesses by other tasks.
A process may only modify its own credentials, and so does not need locking to
access or modify its own credentials.
A mutex (cred_replace_mutex) is added to the task_struct to control the effect
of PTRACE_ATTACHED on credential calculations, particularly with respect to
execve().
With this patch, the contents of an active credentials struct may not be
changed directly; rather a new set of credentials must be prepared, modified
and committed using something like the following sequence of events:
struct cred *new = prepare_creds();
int ret = blah(new);
if (ret < 0) {
abort_creds(new);
return ret;
}
return commit_creds(new);
There are some exceptions to this rule: the keyrings pointed to by the active
credentials may be instantiated - keyrings violate the COW rule as managing
COW keyrings is tricky, given that it is possible for a task to directly alter
the keys in a keyring in use by another task.
To help enforce this, various pointers to sets of credentials, such as those in
the task_struct, are declared const. The purpose of this is compile-time
discouragement of altering credentials through those pointers. Once a set of
credentials has been made public through one of these pointers, it may not be
modified, except under special circumstances:
(1) Its reference count may incremented and decremented.
(2) The keyrings to which it points may be modified, but not replaced.
The only safe way to modify anything else is to create a replacement and commit
using the functions described in Documentation/credentials.txt (which will be
added by a later patch).
This patch and the preceding patches have been tested with the LTP SELinux
testsuite.
This patch makes several logical sets of alteration:
(1) execve().
This now prepares and commits credentials in various places in the
security code rather than altering the current creds directly.
(2) Temporary credential overrides.
do_coredump() and sys_faccessat() now prepare their own credentials and
temporarily override the ones currently on the acting thread, whilst
preventing interference from other threads by holding cred_replace_mutex
on the thread being dumped.
This will be replaced in a future patch by something that hands down the
credentials directly to the functions being called, rather than altering
the task's objective credentials.
(3) LSM interface.
A number of functions have been changed, added or removed:
(*) security_capset_check(), ->capset_check()
(*) security_capset_set(), ->capset_set()
Removed in favour of security_capset().
(*) security_capset(), ->capset()
New. This is passed a pointer to the new creds, a pointer to the old
creds and the proposed capability sets. It should fill in the new
creds or return an error. All pointers, barring the pointer to the
new creds, are now const.
(*) security_bprm_apply_creds(), ->bprm_apply_creds()
Changed; now returns a value, which will cause the process to be
killed if it's an error.
(*) security_task_alloc(), ->task_alloc_security()
Removed in favour of security_prepare_creds().
(*) security_cred_free(), ->cred_free()
New. Free security data attached to cred->security.
(*) security_prepare_creds(), ->cred_prepare()
New. Duplicate any security data attached to cred->security.
(*) security_commit_creds(), ->cred_commit()
New. Apply any security effects for the upcoming installation of new
security by commit_creds().
(*) security_task_post_setuid(), ->task_post_setuid()
Removed in favour of security_task_fix_setuid().
(*) security_task_fix_setuid(), ->task_fix_setuid()
Fix up the proposed new credentials for setuid(). This is used by
cap_set_fix_setuid() to implicitly adjust capabilities in line with
setuid() changes. Changes are made to the new credentials, rather
than the task itself as in security_task_post_setuid().
(*) security_task_reparent_to_init(), ->task_reparent_to_init()
Removed. Instead the task being reparented to init is referred
directly to init's credentials.
NOTE! This results in the loss of some state: SELinux's osid no
longer records the sid of the thread that forked it.
(*) security_key_alloc(), ->key_alloc()
(*) security_key_permission(), ->key_permission()
Changed. These now take cred pointers rather than task pointers to
refer to the security context.
(4) sys_capset().
This has been simplified and uses less locking. The LSM functions it
calls have been merged.
(5) reparent_to_kthreadd().
This gives the current thread the same credentials as init by simply using
commit_thread() to point that way.
(6) __sigqueue_alloc() and switch_uid()
__sigqueue_alloc() can't stop the target task from changing its creds
beneath it, so this function gets a reference to the currently applicable
user_struct which it then passes into the sigqueue struct it returns if
successful.
switch_uid() is now called from commit_creds(), and possibly should be
folded into that. commit_creds() should take care of protecting
__sigqueue_alloc().
(7) [sg]et[ug]id() and co and [sg]et_current_groups.
The set functions now all use prepare_creds(), commit_creds() and
abort_creds() to build and check a new set of credentials before applying
it.
security_task_set[ug]id() is called inside the prepared section. This
guarantees that nothing else will affect the creds until we've finished.
The calling of set_dumpable() has been moved into commit_creds().
Much of the functionality of set_user() has been moved into
commit_creds().
The get functions all simply access the data directly.
(8) security_task_prctl() and cap_task_prctl().
security_task_prctl() has been modified to return -ENOSYS if it doesn't
want to handle a function, or otherwise return the return value directly
rather than through an argument.
Additionally, cap_task_prctl() now prepares a new set of credentials, even
if it doesn't end up using it.
(9) Keyrings.
A number of changes have been made to the keyrings code:
(a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have
all been dropped and built in to the credentials functions directly.
They may want separating out again later.
(b) key_alloc() and search_process_keyrings() now take a cred pointer
rather than a task pointer to specify the security context.
(c) copy_creds() gives a new thread within the same thread group a new
thread keyring if its parent had one, otherwise it discards the thread
keyring.
(d) The authorisation key now points directly to the credentials to extend
the search into rather pointing to the task that carries them.
(e) Installing thread, process or session keyrings causes a new set of
credentials to be created, even though it's not strictly necessary for
process or session keyrings (they're shared).
(10) Usermode helper.
The usermode helper code now carries a cred struct pointer in its
subprocess_info struct instead of a new session keyring pointer. This set
of credentials is derived from init_cred and installed on the new process
after it has been cloned.
call_usermodehelper_setup() allocates the new credentials and
call_usermodehelper_freeinfo() discards them if they haven't been used. A
special cred function (prepare_usermodeinfo_creds()) is provided
specifically for call_usermodehelper_setup() to call.
call_usermodehelper_setkeys() adjusts the credentials to sport the
supplied keyring as the new session keyring.
(11) SELinux.
SELinux has a number of changes, in addition to those to support the LSM
interface changes mentioned above:
(a) selinux_setprocattr() no longer does its check for whether the
current ptracer can access processes with the new SID inside the lock
that covers getting the ptracer's SID. Whilst this lock ensures that
the check is done with the ptracer pinned, the result is only valid
until the lock is released, so there's no point doing it inside the
lock.
(12) is_single_threaded().
This function has been extracted from selinux_setprocattr() and put into
a file of its own in the lib/ directory as join_session_keyring() now
wants to use it too.
The code in SELinux just checked to see whether a task shared mm_structs
with other tasks (CLONE_VM), but that isn't good enough. We really want
to know if they're part of the same thread group (CLONE_THREAD).
(13) nfsd.
The NFS server daemon now has to use the COW credentials to set the
credentials it is going to use. It really needs to pass the credentials
down to the functions it calls, but it can't do that until other patches
in this series have been applied.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
Separate the task security context from task_struct. At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.
Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.
With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
RFC 2623 section 2.3.2 permits the server to bypass gss authentication
checks for certain operations that a client may perform when mounting.
In the case of a client that doesn't have some form of credentials
available to it on boot, this allows it to perform the mount unattended.
(Presumably real file access won't be needed until a user with
credentials logs in.)
Being slightly more lenient allows lots of old clients to access
krb5-only exports, with the only loss being a small amount of
information leaked about the root directory of the export.
This affects only v2 and v3; v4 still requires authentication for all
access.
Thanks to Peter Staubach testing against a Solaris client, which
suggesting addition of v3 getattr, to the list, and to Trond for noting
that doing so exposes no additional information.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Thanks to Frank Van Maarseveen for the original problem report: "A
privileged process on an NFS client which drops privileges after using
them to change the current working directory, will experience incorrect
EACCES after an NFS server reboot. This problem can also occur after
memory pressure on the server, particularly when the client side is
quiet for some time."
This occurs because the filehandle points to a directory whose parents
are no longer in the dentry cache, and we're attempting to reconnect the
directory to its parents without adequate permissions to perform lookups
in the parent directories.
We can therefore fix the problem by acquiring the necessary capabilities
before attempting the reconnection. We do this only in the
no_subtree_check case, since the documented behavior of the
subtree_check export option requires the server to check that the user
has lookup permissions on all parents.
The subtree_check case still has a problem, since reconnect_path()
unnecessarily requires both read and lookup permissions on all parent
directories. However, a fix in that case would be more delicate, and
use of subtree_check is already discouraged for other reasons.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Frank van Maarseveen <frankvm@frankvm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Rename nfsd_permission() specific MAY_* flags to NFSD_MAY_* to make it
clear, that these are not used outside nfsd, and to avoid name and
number space conflicts with the VFS.
[comment from hch: rename MAY_READ, MAY_WRITE and MAY_EXEC as well]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Move the code that actually parses the filehandle and looks up the
dentry and export to a separate function. This simplifies the reference
counting a little and moves fh_verify() a little closer to the kernel
ideal of small, minimally-indentended functions. Clean up a few other
minor style sins along the way.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Neil Brown <neilb@suse.de>
This bug was always here, but before my commit 6fa02839bf
("recheck for secure ports in fh_verify"), it could only be triggered by
failure of a kmalloc(). After that commit it could be triggered by a
client making a request from a non-reserved port for access to an export
marked "secure". (Exports are "secure" by default.)
The result is a struct svc_export with a reference count one too low,
resulting in likely oopses next time the export is accessed.
The reference counting here is not straightforward; a later patch will
clean up fh_verify().
Thanks to Lukas Hejtmanek for the bug report and followup.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Lukas Hejtmanek <xhejtman@ics.muni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sorry for the noise, but here's the v3 of this compilation fix :)
There are some places, which declare the char buf[...] on the stack
to push it later into dprintk(). Since the dprintk sometimes (if the
CONFIG_SYSCTL=n) becomes an empty do { } while (0) stub, these buffers
cause gcc to produce appropriate warnings.
Wrap these buffers with RPC_IFDEBUG macro, as Trond proposed, to
compile them out when not needed.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This header is used only in a few places in fs/nfsd, so there seems to
be little point to having it in include/. (Thanks to Robert Day for
pointing this out.)
Cc: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
As with commit 7fc90ec93a ("knfsd: nfsd:
call nfsd_setuser() on fh_compose(), fix nfsd4 permissions problem")
this is a case where we need to redo a security check in fh_verify()
even though the filehandle already has an associated dentry--if the
filehandle was created by fh_compose() in an earlier operation of the
nfsv4 compound, then we may not have done these checks yet.
Without this fix it is possible, for example, to traverse from an export
without the secure ports requirement to one with it in a single
compound, and bypass the secure port check on the new export.
While we're here, fix up some minor style problems and change a printk()
to a dprintk(), to make it harder for random unprivileged users to spam
the logs.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Reviewed-By: NeilBrown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset is a medium scale rewrite of the export operations interface.
The goal is to make the interface less complex, and easier to understand from
the filesystem side, aswell as preparing generic support for exporting of
64bit inode numbers.
This touches all nfs exporting filesystems, and I've done testing on all of
the filesystems I have here locally (xfs, ext2, ext3, reiserfs, jfs)
This patch:
Add a structured fid type so that we don't have to pass an array of u32 values
around everywhere. It's a union of possible layouts.
As a start there's only the u32 array and the traditional 32bit inode format,
but there will be more in one of my next patchset when I start to document the
various filehandle formats we have in lowlevel filesystems better.
Also add an enum that gives the various filehandle types human- readable
names.
Note: Some people might think the struct containing an anonymous union is
ugly, but I didn't want to pass around a raw union type.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fsid_source decided where to get the 'fsid' number to
return for a GETATTR based on the type of filehandle.
It can be from the device, from the fsid, or from the
UUID.
It is possible for the filehandle to be inconsistent
with the export information, so make sure the export information
actually has the info implied by the value returned by
fsid_source.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: "Luiz Fernando N. Capitulino" <lcapitulino@gmail.com>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Our clients (like other clients, as far as I know) use only auth_sys for nlm,
even when using rpcsec_gss for the main nfs operations.
Administrators that want to deny non-kerberos-authenticated locking requests
will need to turn off NFS protocol versions less than 4....
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow readonly access to vary depending on the pseudoflavor, using the flag
passed with each pseudoflavor in the export downcall. The rest of the flags
are ignored for now, though some day we might also allow id squashing to vary
based on the flavor.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the first actual use of the secinfo information by using it to return
nfserr_wrongsec when an export is found that doesn't allow the flavor used on
this request.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want it to be possible for users to restrict exports both by IP address and
by pseudoflavor. The pseudoflavor information has previously been passed
using special auth_domains stored in the rq_client field. After the preceding
patch that stored the pseudoflavor in rq_pflavor, that's now superfluous; so
now we use rq_client for the ip information, as auth_null and auth_unix do.
However, we keep around the special auth_domain in the rq_gssclient field for
backwards compatibility purposes, so we can still do upcalls using the old
"gss/pseudoflavor" auth_domain if upcalls using the unix domain to give us an
appropriate export. This allows us to continue supporting old mountd.
In fact, for this first patch, we always use the "gss/pseudoflavor"
auth_domain (and only it) if it is available; thus rq_client is ignored in the
auth_gss case, and this patch on its own makes no change in behavior; that
will be left to later patches.
Note on idmap: I'm almost tempted to just replace the auth_domain in the idmap
upcall by a dummy value--no version of idmapd has ever used it, and it's
unlikely anyone really wants to perform idmapping differently depending on the
where the client is (they may want to perform *credential* mapping
differently, but that's a different matter--the idmapper just handles id's
used in getattr and setattr). But I'm updating the idmapd code anyway, just
out of general backwards-compatibility paranoia.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Split the callers of exp_get_by_name(), exp_find(), and exp_parent() into
those that are processing requests and those that are doing other stuff (like
looking up filehandles for mountd).
No change in behavior, just a (fairly pointless, on its own) cleanup.
(Note this has the effect of making nfsd_cross_mnt() pass rqstp->rq_client
instead of exp->ex_client into exp_find_by_name(). However, the two should
have the same value at this point.)
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently exp_find(), exp_get_by_name(), and friends, return an export on
success, and on failure return:
errors -EAGAIN (drop this request pending an upcall) or
-ETIMEDOUT (an upcall has timed out), or
return NULL, which can mean either that there was a memory allocation
failure, or that an export was not found, or that a passed-in
export lacks an auth_domain.
Many callers seem to assume that NULL means that an export was not found,
which may lead to bugs in the case of a memory allocation failure.
Modify these functions to distinguish between the two NULL cases by returning
either -ENOENT or -ENOMEM. They now never return NULL. We get to simplify
some code in the process.
We return -ENOENT in the case of a missing auth_domain. This case should
probably be removed (or converted to a bug) after confirming that it can never
happen.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently NFSD calls directly into filesystems through the export_operations
structure. I plan to change this interface in various ways in later patches,
and want to avoid the export of the default operations to NFSD, so this patch
adds two simple exportfs_encode_fh/exportfs_decode_fh helpers for NFSD to call
instead of poking into exportfs guts.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
currently the export_operation structure and helpers related to it are in
fs.h. fs.h is already far too large and there are very few places needing the
export bits, so split them off into a separate header.
[akpm@linux-foundation.org: fix cifs build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a lookup request arrives, nfsd uses information provided by userspace
(mountd) to find the right filesystem.
It then assumes that the same filehandle type as the incoming filehandle can
be used to create an outgoing filehandle.
However if mountd is buggy, or maybe just being creative, the filesystem may
not support that filesystem type, and the kernel could oops, particularly if
'ex_uuid' is NULL but a FSID_UUID* filehandle type is used.
So add some proper checking that the fsid version/type from the incoming
filehandle is actually supportable, and ignore that information if it isn't
supportable.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
not needed and actually breaks build on frv, while we are at it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for using a filesystem UUID to identify and export point in the
filehandle.
For NFSv2, this UUID is xor-ed down to 4 or 8 bytes so that it doesn't take up
too much room. For NFSv3+, we use the full 16 bytes, and possibly also a
64bit inode number for exports beneath the root of a filesystem.
When generating an fsid to return in 'stat' information, use the UUID (hashed
down to size) if it is available and a small 'fsid' was not specifically
provided.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we are using the same version/fsid as a current filehandle, then there is
no need to verify the the numbers are valid for this export, and they must be
(we used them to find this export).
This allows us to simplify the fsid selection code.
Also change "ref_fh_version" and "ref_fh_fsid_type" to "version" and
"fsid_type", as the important thing isn't that they are the version/type of
the reference filehandle, but they are the chosen type for the new filehandle.
And tidy up some indenting.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are loads of places where the RPC server assumes that the rq_addr fields
contains an IPv4 address. Top among these are error and debugging messages
that display the server's IP address.
Let's refactor the address printing into a separate function that's smart
enough to figure out the difference between IPv4 and IPv6 addresses.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Also remove {NFSD,RPC}_PARANOIA as having the defines doesn't really add
anything.
The printks covered by RPC_PARANOIA were triggered by badly formatted
packets and so should be ratelimited.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To avoid tying up server threads when nfsd makes an upcall (to mountd, to get
export options, to idmapd, for nfsv4 name<->id mapping, etc.), we temporarily
"drop" the request and save enough information so that we can revisit it
later.
Certain failures during the deferral process can cause us to really drop the
request and never revisit it.
This is often less than ideal, and is unacceptable in the NFSv4 case--rfc 3530
forbids the server from dropping a request without also closing the
connection.
As a first step, we modify the deferral code to return -ETIMEDOUT (which is
translated to nfserr_jukebox in the v3 and v4 cases, and remains a drop in the
v2 case).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A recent commit (7fc90ec93a) moved the
call to nfsd_setuser out of the 'find a dentry for a filehandle' branch
of fh_verify so that it would always be called.
This had the unfortunately side-effect of moving *after* the call to
decode_fh, so the prober fsuid was not set when nfsd_acceptable was called,
the 'permission' check did the wrong thing.
This patch moves the nfsd_setuser call back where it was, and add as call
in the other branch of the if.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the typical v2/v3 case the only new filehandles used as arguments to
operations are filehandles taken directly off the wire, which don't get
dentries until fh_verify() is called.
But in v4 the filehandles that are arguments to operations were often created
by previous operations (putrootfh, lookup, etc.) using fh_compose, which sets
the dentry in the filehandle without calling nfsd_setuser().
This also means that, for example, if filesystem B is mounted on filesystem A,
and filesystem A is exported without root-squashing, then a client can bypass
the rootsquashing on B using a compound that starts at a filehandle in A,
crosses into B using lookups, and then does stuff in B.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
nfsd tries to return to a client the same sort of filehandle as was used by
the client. This removes some filehandle aliasing issues and means that a
server upgrade followed by a downgrade will not confused clients not restarted
during that time.
However when crossing a mountpoint, the filehandle used for one filesystem
doesn't provide any useful information on what sort of filehandle should be
used on the other, and can provide misleading information. So if the
reference filehandle is on a different filesystem to the one being generated,
ignore it.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is a perfectly valid situation where fh_update gets called on an already
uptodate filehandle - in nfsd_create_v3 where a CREATE_UNCHECKED finds an
existing file and wants to just set the size.
We could possible optimise out the call in that case, but the only harm
involved is that fh_update prints a warning, so it is easier to remove the
warning.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
.. it makes some of the code nicer.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
