Differentiate the objective and real subjective credentials from the effective
subjective credentials on a task by introducing a second credentials pointer
into the task_struct.
task_struct::real_cred then refers to the objective and apparent real
subjective credentials of a task, as perceived by the other tasks in the
system.
task_struct::cred then refers to the effective subjective credentials of a
task, as used by that task when it's actually running. These are not visible
to the other tasks in the system.
__task_cred(task) then refers to the objective/real credentials of the task in
question.
current_cred() refers to the effective subjective credentials of the current
task.
prepare_creds() uses the objective creds as a base and commit_creds() changes
both pointers in the task_struct (indeed commit_creds() requires them to be the
same).
override_creds() and revert_creds() change the subjective creds pointer only,
and the former returns the old subjective creds. These are used by NFSD,
faccessat() and do_coredump(), and will by used by CacheFiles.
In SELinux, current_has_perm() is provided as an alternative to
task_has_perm(). This uses the effective subjective context of current,
whereas task_has_perm() uses the objective/real context of the subject.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
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>
Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.
The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.
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>
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
Commit 8d7c4203 "nfsd: fix failure to set eof in readdir in some
situations" introduced a bug: on a directory in an exported ext3
filesystem with dir_index unset, a READDIR will only return about 250
entries, even if the directory was larger.
Bisected it back to this commit; reverting it fixes the problem.
It turns out that in this case ext3 reads a block at a time, then
returns from readdir, which means we can end up with buf.full==0 but
with more entries in the directory still to be read. Before 8d7c4203
(but after c002a6c797 "Optimise NFS readdir hack slightly"), this would
cause us to return the READDIR result immediately, but with the eof bit
unset. That could cause a performance regression (because the client
would need more roundtrips to the server to read the whole directory),
but no loss in correctness, since the cleared eof bit caused the client
to send another readdir. After 8d7c4203, the setting of the eof bit
made this a correctness problem.
So, move nfserr_eof into the loop and remove the buf.full check so that
we loop until buf.used==0. The following seems to do the right thing
and reduces the network traffic since we don't return a READDIR result
until the buffer is full.
Tested on an empty directory & large directory; eof is properly sent and
there are no more short buffers.
Signed-off-by: Doug Nazar <nazard@dragoninc.ca>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before 14f7dd6320 "[PATCH] Copy XFS
readdir hack into nfsd code", readdir_cd->err was reset to eof before
each call to vfs_readdir; afterwards, it is set only once. Similarly,
c002a6c797 "[PATCH] Optimise NFS readdir
hack slightly", can cause us to exit without nfserr_eof set. Fix this.
This ensures the "eof" bit is set when needed in readdir replies. (The
particular case I saw was an nfsv4 readdir of an empty directory, which
returned with no entries (the protocol requires "." and ".." to be
filtered out), but with eof unset.)
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Avoid calling the underlying ->readdir() again when we reached the end
already; keep going round the loop only if we stopped due to our own
buffer being full.
[AV: tidy the things up a bit, while we are there]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It's not the final state, but it allows moving ->readdir() instances
to passing filldir return value to caller of vfs_readdir().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Some file systems with their own internal locking have problems with the
way that nfsd calls the ->lookup() method from within a filldir function
called from their ->readdir() method. The recursion back into the file
system code can cause deadlock.
XFS has a fairly hackish solution to this which involves doing the
readdir() into a locally-allocated buffer, then going back through it
calling the filldir function afterwards. It's not ideal, but it works.
It's particularly suboptimal because XFS does this for local file
systems too, where it's completely unnecessary.
Copy this hack into the NFS code where it can be used only for NFS
export. In response to feedback, use it unconditionally rather than only
for the affected file systems.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We might as well do all of these at the end. Fix up a couple minor
style nits while we're there.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Drop reference to export key on error. Compile tested.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Fix a memory leak in nfsd_getxattr. nfsd_getxattr should free up memory
that it allocated if vfs_getxattr fails.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The Linux NFS server can be started via a user-space write to
/proc/fs/nfs/threads or to /proc/fs/nfs/portlist. In the first case,
all default listeners are started (both UDP and TCP). In the second,
a listener is started only for one specified transport.
The NFS server has to make sure lockd stays up until the last listener
transport goes away. To support both start-up interfaces, it should
do one lockd_up() for each NFSD listener.
The nfsd_init_socks() function used to do one lockd_up() call for each
svc_create_xprt(). Recently commit
26a4140923 mistakenly changed
nfsd_init_socks() to do only one lockd_up() call even though it still
does two svc_create_xprt() calls.
The end result is a lockd_down() BUG during NFSD shutdown processing
because nfsd_last_threads() does a lockd_down() call for each entry
on the sv_permsocks list, but the start-up code doesn't do a matching
number of lockd_up() calls.
Add a second lockd_up() in nfsd_init_socks() to make sure the number
of lockd_up() calls matches the number of entries on the NFS servers's
sv_permsocks list.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: The svc_addsock() function no longer uses its "proto"
argument, so remove it.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: Now that lockd_up() starts listeners for both transports, the
"proto" argument is no longer needed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Rewrite grace period code to unify management of grace period across
lockd and nfsd. The current code has lockd and nfsd cooperate to
compute a grace period which is satisfactory to them both, and then
individually enforce it. This creates a slight race condition, since
the enforcement is not coordinated. It's also more complicated than
necessary.
Here instead we have lockd and nfsd each inform common code when they
enter the grace period, and when they're ready to leave the grace
period, and allow normal locking only after both of them are ready to
leave.
We also expect the locks_start_grace()/locks_end_grace() interface here
to be simpler to build on for future cluster/high-availability work,
which may require (for example) putting individual filesystems into
grace, or enforcing grace periods across multiple cluster nodes.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
since commit ff7d9756b5
"nfsd: use static memory for callback program and stats"
do_probe_callback uses a static callback program
(NFS4_CALLBACK) rather than the one set in clp->cl_callback.cb_prog
as passed in by the client in setclientid (4.0)
or create_session (4.1).
This patches introduces rpc_create_args.prognumber that allows
overriding program->number when creating rpc_clnt.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Now that cb_stats are static (since commit
ff7d9756b5)
there's no need to clear them.
Initially I thought it might make sense to do
that every callback probing but since the stats
are per-program and they are shared between possibly
several client callback instances, zeroing them out
seems like the wrong thing to do.
Note that that commit also introduced a bug
since stats.program is also being cleared in the process
and it is not restored after the memset as it used to be.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
I had a report from someone building a large NFS server that they were
unable to start more than 585 nfsd threads. It was reported against an
older kernel using the slab allocator, and I tracked it down to the
large allocation in nfsd_racache_init failing.
It appears that the slub allocator handles large allocations better,
but large contiguous allocations can often be problematic. There
doesn't seem to be any reason that the racache has to be allocated as a
single large chunk. This patch breaks this up so that the racache is
built up from separate allocations.
(Thanks also to Takashi Iwai for a bugfix.)
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Takashi Iwai <tiwai@suse.de>
After using the encode_stateid helper the "p" pointer declared
by ENCODE_SEQID_OP_HEAD is warned as unused.
In the single site where it is still needed it can be declared
separately using the ENCODE_HEAD macro.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
nfsd4_encode_open first reservation is currently for 36 + sizeof(stateid_t)
while it writes after the stateid a cinfo (20 bytes) and 5 more 4-bytes
words, for a total of 40 + sizeof(stateid_t).
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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>
Introduce and initialize an address family field in the svc_serv structure.
This field will determine what family to use for the service's listener
sockets and what families are advertised via the local rpcbind daemon.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The array we kmalloc() here is not large enough.
Thanks to Johann Dahm and David Richter for bug report and testing.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: David Richter <richterd@citi.umich.edu>
Tested-by: Johann Dahm <jdahm@umich.edu>
Move the cstate_alloc call so that if it fails, the response is setup to
encode the NFS error. The out label now means that the
nfsd4_compound_state has not been allocated.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
There doesn't seem to be a compelling reason why nfsd4_op_name() is
marked as "inline":
It's only used in a dprintk(), and as long as it has only one caller
non-ancient gcc versions anyway inline it automatically.
This patch fixes the following compile error with gcc 3.4:
...
CC fs/nfsd/nfs4proc.o
nfs4proc.c: In function `nfsd4_proc_compound':
nfs4proc.c:854: sorry, unimplemented: inlining failed in call to
nfs4proc.c:897: sorry, unimplemented: called from here
make[3]: *** [fs/nfsd/nfs4proc.o] Error 1
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
[ Also made it "const char *" - Linus]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Once clp is assigned, it never becomes NULL, so we can make a label for it
in the error handling code. Because the call to path_lookup follows the
call to auth_domain_find, its error handling code should jump to this new
label.
The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r@
expression x,E;
statement S;
position p1,p2,p3;
@@
(
if ((x = auth_domain_find@p1(...)) == NULL || ...) S
|
x = auth_domain_find@p1(...)
... when != x
if (x == NULL || ...) S
)
<...
if@p3 (...) { ... when != auth_domain_put(x)
when != if (x) { ... auth_domain_put(x); ...}
return@p2 ...;
}
...>
(
return x;
|
return 0;
|
x = E
|
E = x
|
auth_domain_put(x)
)
@exists@
position r.p1,r.p2,r.p3;
expression x;
int ret != 0;
statement S;
@@
* x = auth_domain_find@p1(...)
<...
* if@p3 (...)
S
...>
* return@p2 \(NULL\|ret\);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs.h needs path.h, not namei.h; nfs_fs.h doesn't need it at all.
Several places in the tree needed direct include.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Remove the unused mode parameter from vfs_symlink and callers.
Thanks to Tetsuo Handa for noticing.
CC: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Fix nlm_fopen() to return NLM_FAILED (or NLM_LCK_DENIED_NOLOCKS) instead
of NLM_LCK_DENIED. The latter means the lock request failed because of a
conflicting lock (i.e. a temporary error), which is wrong in this case.
Also fix the client to return ENOLCK instead of EAGAIN if a blocking lock
request returns with NLM_LOCK_DENIED.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.27' of git://linux-nfs.org/~bfields/linux: (51 commits)
nfsd: nfs4xdr.c do-while is not a compound statement
nfsd: Use C99 initializers in fs/nfsd/nfs4xdr.c
lockd: Pass "struct sockaddr *" to new failover-by-IP function
lockd: get host reference in nlmsvc_create_block() instead of callers
lockd: minor svclock.c style fixes
lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_lock
lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_testlock
lockd: nlm_release_host() checks for NULL, caller needn't
file lock: reorder struct file_lock to save space on 64 bit builds
nfsd: take file and mnt write in nfs4_upgrade_open
nfsd: document open share bit tracking
nfsd: tabulate nfs4 xdr encoding functions
nfsd: dprint operation names
svcrdma: Change WR context get/put to use the kmem cache
svcrdma: Create a kmem cache for the WR contexts
svcrdma: Add flush_scheduled_work to module exit function
svcrdma: Limit ORD based on client's advertised IRD
svcrdma: Remove unused wait q from svcrdma_xprt structure
svcrdma: Remove unneeded spin locks from __svc_rdma_free
svcrdma: Add dma map count and WARN_ON
...
The WRITEMEM macro produces sparse warnings of the form:
fs/nfsd/nfs4xdr.c:2668:2: warning: do-while statement is not a compound statement
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Thanks to problem report and original patch from Harvey Harrison.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Benny Halevy <bhalevy@panasas.com>
Pass a more generic socket address type to nlmsvc_unlock_all_by_ip() to
allow for future support of IPv6. Also provide additional sanity
checking in failover_unlock_ip() when constructing the server's IP
address.
As an added bonus, provide clean kerneldoc comments on related NLM
interfaces which were recently added.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The cl_chatty flag alows us to control whether a given rpc client leaves
"server X not responding, timed out"
messages in the syslog. Such messages make sense for ordinary nfs
clients (where an unresponsive server means applications on the
mountpoint are probably hanging), but not for the callback client (which
can fail more commonly, with the only result just of disabling some
optimizations).
Previously cl_chatty was removed, do to lack of users; reinstate it, and
use it for the nfsd's callback client.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It's not immediately obvious from the code why we're doing this.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Benny Halevy <bhalevy@panasas.com>
In preparation for minorversion 1
All encoders now return an nfserr status (typically their
nfserr argument). Unsupported ops go through nfsd4_encode_operation
too, so use nfsd4_encode_noop to encode nothing for their reply body.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Have separate vectors of operation decoders for each minorversion.
Obsolete ops in newer minorversions have default implementation returning
nfserr_opnotsupp.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Check minorversion once before decoding any operation and reject with
nfserr_minor_vers_mismatch if != 0 (this still happens in nfsd4_proc_compound).
In this case return a zero length resultdata array as required by RFC3530.
minorversion 1 processing will have its own vector of decoders.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Multiple mnt_want_write() calls in the switch statement looks really
ugly.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
knfsd currently uses 2 signal masks when processing requests. A "loose"
mask (SHUTDOWN_SIGS) that it uses when receiving network requests, and
then a more "strict" mask (ALLOWED_SIGS, which is just SIGKILL) that it
allows when doing the actual operation on the local storage.
This is apparently unnecessarily complicated. The underlying filesystem
should be able to sanely handle a signal in the middle of an operation.
This patch removes the signal mask handling from knfsd altogether. When
knfsd is started as a kthread, all signals are ignored. It then allows
all of the signals in SHUTDOWN_SIGS. There's no need to set the mask
as well.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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>
OCFS2 can return -ERESTARTSYS from write requests (and possibly
elsewhere) if there is a signal pending.
If nfsd is shutdown (by sending a signal to each thread) while there
is still an IO load from the client, each thread could handle one last
request with a signal pending. This can result in -ERESTARTSYS
which is not understood by nfserrno() and so is reflected back to
the client as nfserr_io aka -EIO. This is wrong.
Instead, interpret ERESTARTSYS to mean "try again later" by returning
nfserr_jukebox. The client will resend and - if the server is
restarted - the write will (hopefully) be successful and everyone will
be happy.
The symptom that I narrowed down to this was:
copy a large file via NFS to an OCFS2 filesystem, and restart
the nfs server during the copy.
The 'cp' might get an -EIO, and the file will be corrupted -
presumably holes in the middle where writes appeared to fail.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We need the nfsd_mutex before accessing nfsd_serv->sv_nrthreads or we
can't even guarantee nfsd_serv will still be there.
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Since we no longer make any distinction between shutdown signals with
nfsd, then it becomes easier to just standardize on a particular signal
to use to bring it down (SIGINT, in this case).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This patch is rather large, but I couldn't figure out a way to break it
up that would remain bisectable. It does several things:
- change svc_thread_fn typedef to better match what kthread_create expects
- change svc_pool_map_set_cpumask to be more kthread friendly. Make it
take a task arg and and get rid of the "oldmask"
- have svc_set_num_threads call kthread_create directly
- eliminate __svc_create_thread
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The special handling for SIGHUP in knfsd is a holdover from much
earlier versions of Linux where reloading the export table was
more expensive. That facility is not really needed anymore and
to my knowledge, is seldom-used.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Several of the nfsd filesystem interfaces allow changes to parameters
that don't have any effect on a running nfsd service. They are only ever
checked when nfsd is started. This patch fixes it so that changes to
those procfiles return -EBUSY if nfsd is already running to make it
clear that changes on the fly don't work.
The patch should also close some relatively harmless races between
changing the info in those interfaces and starting nfsd, since these
variables are being moved under the protection of the nfsd_mutex.
Finally, the nfsv4recoverydir file always returns -EINVAL if read. This
patch fixes it to return the recoverydir path as expected.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This removes the BKL from the RPC service creation codepath. The BKL
really isn't adequate for this job since some of this info needs
protection across sleeps.
Also, add some comments to try and clarify how the locking should work
and to make it clear that the BKL isn't necessary as long as there is
adequate locking between tasks when touching the svc_serv fields.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
WRITEMEM zeroes the last word in the destination buffer
for padding purposes, but this must not be done if
no bytes are to be copied, as it would result
in zeroing of the word right before the array.
The current implementation works since it's always called
with non zero nbytes or it follows an encoding of the
string (or opaque) length which, if equal to zero,
can be overwritten with zero.
Nevertheless, it seems safer to check for this case.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We already print each operation of the compound when debugging is turned
on; printing the result could also help with remote debugging.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
These bit operations don't need to be atomic. They're all done under a
single big mutex anyway.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use proc_create() to make sure that ->proc_fops be setup before gluing PDE to
main tree.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Presumably this is left over from earlier drafts of v4, which listed
TIME_METADATA as writeable. It's read-only in rfc 3530, and shouldn't
be modifiable anyway.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The file_lock structure is used both as a heavy-weight representation of
an active lock, with pointers to reference-counted structures, etc., and
as a simple container for parameters that describe a file lock.
The conflicting lock returned from __posix_lock_file is an example of
the latter; so don't call the filesystem or lock manager callbacks when
copying to it. This also saves the need for an unnecessary
locks_init_lock in the nfsv4 server.
Thanks to Trond for pointing out the error.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Add /proc/fs/nfsd/unlock_filesystem, which allows e.g.:
shell> echo /mnt/sfs1 > /proc/fs/nfsd/unlock_filesystem
so that a filesystem can be unmounted before allowing a peer nfsd to
take over nfs service for the filesystem.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/lockd/svcsubs.c | 66 +++++++++++++++++++++++++++++++++++++++-----
fs/nfsd/nfsctl.c | 65 +++++++++++++++++++++++++++++++++++++++++++
include/linux/lockd/lockd.h | 7 ++++
3 files changed, 131 insertions(+), 7 deletions(-)
For high-availability NFS service, we generally need to be able to drop
file locks held on the exported filesystem before moving clients to a
new server. Currently the only way to do that is by shutting down lockd
entirely, which is often undesireable (for example, if you want to
continue exporting other filesystems).
This patch allows the administrator to release all locks held by clients
accessing the client through a given server ip address, by echoing that
address to a new file, /proc/fs/nfsd/unlock_ip, as in:
shell> echo 10.1.1.2 > /proc/fs/nfsd/unlock_ip
The expected sequence of events can be:
1. Tear down the IP address
2. Unexport the path
3. Write IP to /proc/fs/nfsd/unlock_ip to unlock files
4. Signal peer to begin take-over.
For now we only support IPv4 addresses and NFSv2/v3 (NFSv4 locks are not
affected).
Also, if unmounting the filesystem is required, we assume at step 3 that
clients using the given server ip are the only clients holding locks on
the given filesystem; otherwise, an additional patch is required to
allow revoking all locks held by lockd on a given filesystem.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/lockd/svcsubs.c | 66 +++++++++++++++++++++++++++++++++++++++-----
fs/nfsd/nfsctl.c | 65 +++++++++++++++++++++++++++++++++++++++++++
include/linux/lockd/lockd.h | 7 ++++
3 files changed, 131 insertions(+), 7 deletions(-)
Currently, knfsd only clears the setuid bit if the owner of a file is
changed on a SETATTR call, and only clears the setgid bit if the group
is changed. POSIX says this in the spec for chown():
"If the specified file is a regular file, one or more of the
S_IXUSR, S_IXGRP, or S_IXOTH bits of the file mode are set, and the
process does not have appropriate privileges, the set-user-ID
(S_ISUID) and set-group-ID (S_ISGID) bits of the file mode shall
be cleared upon successful return from chown()."
If I'm reading this correctly, then knfsd is doing this wrong. It should
be clearing both the setuid and setgid bit on any SETATTR that changes
the uid or gid. This wasn't really as noticable before, but now that the
ATTR_KILL_S*ID bits are a no-op for the NFS client, it's more evident.
This patch corrects the nfsd_setattr logic so that this occurs. It also
does a bit of cleanup to the function.
There is also one small behavioral change. If a SETATTR call comes in
that changes the uid/gid and the mode, then we now only clear the setgid
bit if the group execute bit isn't set. The setgid bit without a group
execute bit signifies mandatory locking and we likely don't want to
clear the bit in that case. Since there is no call in POSIX that should
generate a SETATTR call like this, then this should rarely happen, but
it's worth noting.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
There's no need to dynamically allocate this memory, and doing so may
create the possibility of races on shutdown of the rpc client. (We've
witnessed it only after adding rpcsec_gss support to the server, after
which the rpc code can send destroys calls that expect to still be able
to access the rpc_stats structure after it has been destroyed.)
Such races are in theory possible if the module containing this "static"
memory is removed very quickly after an rpc client is destroyed, but
we haven't seen that happen.
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>
While lease is correctly checked by supplying the type argument to
vfs_setlease(), it's stored with fl_type uninitialized. This breaks the
logic when checking the type of the lease. The fix is to initialize
fl_type.
The old code still happened to function correctly since F_RDLCK is zero,
and we only implement read delegations currently (nor write
delegations). But that's no excuse for not fixing this.
Signed-off-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/nfsd/vfs.c:991:27: warning: Using plain integer as NULL pointer
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Add extern to nfsd/nfsd.h
fs/nfsd/nfssvc.c:146:5: warning: symbol 'nfsd_nrthreads' was not declared. Should it be static?
fs/nfsd/nfssvc.c:261:5: warning: symbol 'nfsd_nrpools' was not declared. Should it be static?
fs/nfsd/nfssvc.c:269:5: warning: symbol 'nfsd_get_nrthreads' was not declared. Should it be static?
fs/nfsd/nfssvc.c:281:5: warning: symbol 'nfsd_set_nrthreads' was not declared. Should it be static?
fs/nfsd/export.c:1534:23: warning: symbol 'nfs_exports_op' was not declared. Should it be static?
Add include of auth.h
fs/nfsd/auth.c:27:5: warning: symbol 'nfsd_setuser' was not declared. Should it be static?
Make static, move forward declaration closer to where it's needed.
fs/nfsd/nfs4state.c:1877:1: warning: symbol 'laundromat_main' was not declared. Should it be static?
Make static, forward declaration was already marked static.
fs/nfsd/nfs4idmap.c:206:1: warning: symbol 'idtoname_parse' was not declared. Should it be static?
fs/nfsd/vfs.c:1156:1: warning: symbol 'nfsd_create_setattr' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This patch makes the needlessly global nfsd_create_setattr() static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Likewise, distros usually leave CONFIG_NFSD_TCP enabled.
TCP support in the Linux NFS server is stable enough that we can leave it
on always. CONFIG_NFSD_TCP adds about 10 lines of code, and defaults to
"Y" anyway.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The code here is difficult to understand; attempt to clarify somewhat by
pulling out one of the more mystifying conditionals into a separate
function.
While we're here, also add lease_time to the list of attributes that we
don't really need to cross a mountpoint to fetch.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
This adds IPv6 support to the interfaces that are used to express nfsd
exports. All addressed are stored internally as IPv6; backwards
compatibility is maintained using mapped addresses.
Thanks to Bruce Fields, Brian Haley, Neil Brown and Hideaki Joshifuji
for comments
Signed-off-by: Aurelien Charbon <aurelien.charbon@bull.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Brian Haley <brian.haley@hp.com>
Cc: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If we depend on the inodes for writeability, we will not catch the r/o mounts
when implemented.
This patches uses __mnt_want_write(). It does not guarantee that the mount
will stay writeable after the check. But, this is OK for one of the checks
because it is just for a printk().
The other two are probably unnecessary and duplicate existing checks in the
VFS. This won't make them better checks than before, but it will make them
detect r/o mounts.
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This basically audits the callers of xattr_permission(), which calls
permission() and can perform writes to the filesystem.
[AV: add missing parts - removexattr() and nfsd posix acls, plug for a leak
spotted by Miklos]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This also uses the little helper in the NFS code to make an if() a little bit
less ugly. We introduced the helper at the beginning of the series.
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This takes care of all of the direct callers of vfs_mknod().
Since a few of these cases also handle normal file creation
as well, this also covers some calls to vfs_create().
So that we don't have to make three mnt_want/drop_write()
calls inside of the switch statement, we move some of its
logic outside of the switch and into a helper function
suggested by Christoph.
This also encapsulates a fix for mknod(S_IFREG) that Miklos
found.
[AV: merged mkdir handling, added missing nfsd pieces]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Elevate the write count during the vfs_rmdir() and vfs_unlink().
[AV: merged rmdir and unlink parts, added missing pieces in nfsd]
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
