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Author SHA1 Message Date
David Woodhouse
2f9092e102 Fix i_mutex vs. readdir handling in nfsd
Commit 14f7dd63 ("Copy XFS readdir hack into nfsd code") introduced a
bug to generic code which had been extant for a long time in the XFS
version -- it started to call through into lookup_one_len() and hence
into the file systems' ->lookup() methods without i_mutex held on the
directory.

This patch fixes it by locking the directory's i_mutex again before
calling the filldir functions. The original deadlocks which commit
14f7dd63 was designed to avoid are still avoided, because they were due
to fs-internal locking, not i_mutex.

While we're at it, fix the return type of nfsd_buffered_readdir() which
should be a __be32 not an int -- it's an NFS errno, not a Linux errno.
And return nfserrno(-ENOMEM) when allocation fails, not just -ENOMEM.
Sparse would have caught that, if it wasn't so busy bitching about
__cold__.

Commit 05f4f678 ("nfsd4: don't do lookup within readdir in recovery
code") introduced a similar problem with calling lookup_one_len()
without i_mutex, which this patch also addresses. To fix that, it was
necessary to fix the called functions so that they expect i_mutex to be
held; that part was done by J. Bruce Fields.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Umm-I-can-live-with-that-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Tested-by: J. Bruce Fields <bfields@citi.umich.edu>
LKML-Reference: <8036.1237474444@jrobl>
Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:01:16 -04:00
Al Viro
1644ccc8a9 Safer nfsd_cross_mnt()
AFAICS, we have a subtle bug there: if we have crossed mountpoint
*and* it got mount --move'd away, we'll be holding only one
reference to fs containing dentry - exp->ex_path.mnt.  IOW, we
ought to dput() before exp_put().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:01:15 -04:00
Linus Torvalds
a63856252d Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux: (81 commits)
  nfsd41: define nfsd4_set_statp as noop for !CONFIG_NFSD_V4
  nfsd41: define NFSD_DRC_SIZE_SHIFT in set_max_drc
  nfsd41: Documentation/filesystems/nfs41-server.txt
  nfsd41: CREATE_EXCLUSIVE4_1
  nfsd41: SUPPATTR_EXCLCREAT attribute
  nfsd41: support for 3-word long attribute bitmask
  nfsd: dynamically skip encoded fattr bitmap in _nfsd4_verify
  nfsd41: pass writable attrs mask to nfsd4_decode_fattr
  nfsd41: provide support for minor version 1 at rpc level
  nfsd41: control nfsv4.1 svc via /proc/fs/nfsd/versions
  nfsd41: add OPEN4_SHARE_ACCESS_WANT nfs4_stateid bmap
  nfsd41: access_valid
  nfsd41: clientid handling
  nfsd41: check encode size for sessions maxresponse cached
  nfsd41: stateid handling
  nfsd: pass nfsd4_compound_state* to nfs4_preprocess_{state,seq}id_op
  nfsd41: destroy_session operation
  nfsd41: non-page DRC for solo sequence responses
  nfsd41: Add a create session replay cache
  nfsd41: create_session operation
  ...
2009-04-06 13:25:56 -07:00
Linus Torvalds
2c9e15a011 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6: (27 commits)
  ext2: Zero our b_size in ext2_quota_read()
  trivial: fix typos/grammar errors in fs/Kconfig
  quota: Coding style fixes
  quota: Remove superfluous inlines
  quota: Remove uppercase aliases for quota functions.
  nfsd: Use lowercase names of quota functions
  jfs: Use lowercase names of quota functions
  udf: Use lowercase names of quota functions
  ufs: Use lowercase names of quota functions
  reiserfs: Use lowercase names of quota functions
  ext4: Use lowercase names of quota functions
  ext3: Use lowercase names of quota functions
  ext2: Use lowercase names of quota functions
  ramfs: Remove quota call
  vfs: Use lowercase names of quota functions
  quota: Remove dqbuf_t and other cleanups
  quota: Remove NODQUOT macro
  quota: Make global quota locks cacheline aligned
  quota: Move quota files into separate directory
  ext4: quota reservation for delayed allocation
  ...
2009-03-27 14:48:34 -07:00
Jan Kara
90c0af05a5 nfsd: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

CC: bfields@fieldses.org
CC: neilb@suse.de
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:37 +01:00
Sachin S. Prabhu
0953e620de Inconsistent setattr behaviour
There is an inconsistency seen in the behaviour of nfs compared to other local
filesystems on linux when changing owner or group of a directory. If the
directory has SUID/SGID flags set, on changing owner or group on the directory,
the flags are stripped off on nfs. These flags are maintained on other
filesystems such as ext3.

To reproduce on a nfs share or local filesystem, run the following commands
mkdir test; chmod +s+g test; chown user1 test; ls -ld test

On the nfs share, the flags are stripped and the output seen is
drwxr-xr-x 2 user1 root 4096 Feb 23  2009 test

On other local filesystems(ex: ext3), the flags are not stripped and the output
seen is
drwsr-sr-x 2 user1 root 4096 Feb 23 13:57 test

chown_common() called from sys_chown() will only strip the flags if the inode is
not a directory.
static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
{
..
        if (!S_ISDIR(inode->i_mode))
                newattrs.ia_valid |=
                        ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
..
}

See: http://www.opengroup.org/onlinepubs/7990989775/xsh/chown.html

"If the path argument refers to a regular file, the set-user-ID (S_ISUID) and
set-group-ID (S_ISGID) bits of the file mode are cleared upon successful return
from chown(), unless the call is made by a process with appropriate privileges,
in which case it is implementation-dependent whether these bits are altered. If
chown() is successfully invoked on a file that is not a regular file, these
bits may be cleared. These bits are defined in <sys/stat.h>."

The behaviour as it stands does not appear to violate POSIX.  However the
actions performed are inconsistent when comparing ext3 and nfs.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-03-18 17:59:37 -04:00
David Shaw
31dec2538e Short write in nfsd becomes a full write to the client
If a filesystem being written to via NFS returns a short write count
(as opposed to an error) to nfsd, nfsd treats that as a success for
the entire write, rather than the short count that actually succeeded.

For example, given a 8192 byte write, if the underlying filesystem
only writes 4096 bytes, nfsd will ack back to the nfs client that all
8192 bytes were written.  The nfs client does have retry logic for
short writes, but this is never called as the client is told the
complete write succeeded.

There are probably other ways it could happen, but in my case it
happened with a fuse (filesystem in userspace) filesystem which can
rather easily have a partial write.

Here is a patch to properly return the short write count to the
client.

Signed-off-by: David Shaw <dshaw@jabberwocky.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-03-18 17:38:40 -04:00
wengang wang
4ac35c2f79 nfsd(v2/v3): fix the failure of creation from HPUX client
sometimes HPUX nfs client sends a create request to linux nfs server(v2/v3).
the dump of the request is like:
    obj_attributes
        mode: value follows
            set_it: value follows (1)
            mode: 00
        uid: no value
            set_it: no value (0)
        gid: value follows
            set_it: value follows (1)
            gid: 8030
        size: value follows
            set_it: value follows (1)
            size: 0
        atime: don't change
            set_it: don't change (0)
        mtime: don't change
            set_it: don't change (0)

note that mode is 00(havs no rwx privilege even for the owner) and it requires
to set size to 0.

as current nfsd(v2/v3) implementation, the server does mainly 2 steps:
1) creates the file in mode specified by calling vfs_create().
2) sets attributes for the file by calling nfsd_setattr().

at step 2), it finally calls file system specific setattr() function which may
fail when checking permission because changing size needs WRITE privilege but
it has none since mode is 000.

for this case, a new file created, we may simply ignore the request of
setting size to 0, so that WRITE privilege is not needed and the open
succeeds.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
--
 vfs.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-03-18 17:30:50 -04:00
Jonathan Corbet
db1dd4d376 Use f_lock to protect f_flags
Traditionally, changes to struct file->f_flags have been done under BKL
protection, or with no protection at all.  This patch causes all f_flags
changes after file open/creation time to be done under protection of
f_lock.  This allows the removal of some BKL usage and fixes a number of
longstanding (if microscopic) races.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2009-03-16 08:32:27 -06:00
J. Bruce Fields
9a8d248e2d nfsd: fix double-locks of directory mutex
A number of nfsd operations depend on the i_mutex to cover more code
than just the fsync, so the approach of 4c728ef583 "add a vfs_fsync
helper" doesn't work for nfsd.  Revert the parts of those patches that
touch nfsd.

Note: we can't, however, remove the logic from vfs_fsync that was needed
only for the special case of nfsd, because a vfs_fsync(NULL,...) call
can still result indirectly from a stackable filesystem that was called
by nfsd.  (Thanks to Christoph Hellwig for pointing this out.)

Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-07 15:40:45 -05:00
Christoph Hellwig
4c728ef583 add a vfs_fsync helper
Fsync currently has a fdatawrite/fdatawait pair around the method call,
and a mutex_lock/unlock of the inode mutex.  All callers of fsync have
to duplicate this, but we have a few and most of them don't quite get
it right.  This patch adds a new vfs_fsync that takes care of this.
It's a little more complicated as usual as ->fsync might get a NULL file
pointer and just a dentry from nfsd, but otherwise gets afile and we
want to take the mapping and file operations from it when it is there.

Notes on the fsync callers:

 - ecryptfs wasn't calling filemap_fdatawrite / filemap_fdatawait on the
   	lower file
 - coda wasn't calling filemap_fdatawrite / filemap_fdatawait on the host
	file, and returning 0 when ->fsync was missing
 - shm wasn't calling either filemap_fdatawrite / filemap_fdatawait nor
   taking i_mutex.  Now given that shared memory doesn't have disk
   backing not doing anything in fsync seems fine and I left it out of
   the vfs_fsync conversion for now, but in that case we might just
   not pass it through to the lower file at all but just call the no-op
   simple_sync_file directly.

[and now actually export vfs_fsync]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
Al Viro
acfa4380ef inode->i_op is never NULL
We used to have rather schizophrenic set of checks for NULL ->i_op even
though it had been eliminated years ago.  You'd need to go out of your
way to set it to NULL explicitly _and_ a bunch of code would die on
such inodes anyway.  After killing two remaining places that still
did that bogosity, all that crap can go away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
James Morris
2b82892565 Merge branch 'master' into next
Conflicts:
	security/keys/internal.h
	security/keys/process_keys.c
	security/keys/request_key.c

Fixed conflicts above by using the non 'tsk' versions.

Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 11:29:12 +11:00
David Howells
745ca2475a CRED: Pass credentials through dentry_open()
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>
2008-11-14 10:39:22 +11:00
David Howells
5cc0a84076 CRED: Wrap task credential accesses in the NFS daemon
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>
2008-11-14 10:38:58 +11:00
Doug Nazar
b726e923ea Fix nfsd truncation of readdir results
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>
2008-11-09 15:15:50 -05:00
J. Bruce Fields
8d7c4203c6 nfsd: fix failure to set eof in readdir in some situations
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>
2008-10-30 17:16:49 -04:00
Linus Torvalds
5ed487bc2c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (46 commits)
  [PATCH] fs: add a sanity check in d_free
  [PATCH] i_version: remount support
  [patch] vfs: make security_inode_setattr() calling consistent
  [patch 1/3] FS_MBCACHE: don't needlessly make it built-in
  [PATCH] move executable checking into ->permission()
  [PATCH] fs/dcache.c: update comment of d_validate()
  [RFC PATCH] touch_mnt_namespace when the mount flags change
  [PATCH] reiserfs: add missing llseek method
  [PATCH] fix ->llseek for more directories
  [PATCH vfs-2.6 6/6] vfs: add LOOKUP_RENAME_TARGET intent
  [PATCH vfs-2.6 5/6] vfs: remove LOOKUP_PARENT from non LOOKUP_PARENT lookup
  [PATCH vfs-2.6 4/6] vfs: remove unnecessary fsnotify_d_instantiate()
  [PATCH vfs-2.6 3/6] vfs: add __d_instantiate() helper
  [PATCH vfs-2.6 2/6] vfs: add d_ancestor()
  [PATCH vfs-2.6 1/6] vfs: replace parent == dentry->d_parent by IS_ROOT()
  [PATCH] get rid of on-stack dentry in udf
  [PATCH 2/2] anondev: switch to IDA
  [PATCH 1/2] anondev: init IDR statically
  [JFFS2] Use d_splice_alias() not d_add() in jffs2_lookup()
  [PATCH] Optimise NFS readdir hack slightly.
  ...
2008-10-23 10:22:40 -07:00
David Woodhouse
c002a6c797 [PATCH] Optimise NFS readdir hack slightly.
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>
2008-10-23 05:13:11 -04:00
Al Viro
53c9c5c0e3 [PATCH] prepare vfs_readdir() callers to returning filldir result
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>
2008-10-23 05:13:10 -04:00
David Woodhouse
14f7dd6320 [PATCH] Copy XFS readdir hack into nfsd code.
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>
2008-10-23 05:13:05 -04:00
David Woodhouse
2628b76636 [PATCH] Factor out nfsd_do_readdir() into its own function
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23 05:13:04 -04:00
Krishna Kumar
6c6a426fdc nfsd: Fix memory leak in nfsd_getxattr
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>
2008-10-22 14:00:45 -04:00
Jeff Layton
54a66e5480 knfsd: allocate readahead cache in individual chunks
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>
2008-09-29 17:56:59 -04:00
J. Bruce Fields
04716e6621 nfsd: permit unauthenticated stat of export root
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>
2008-09-29 17:56:56 -04:00
Al Viro
f419a2e3b6 [PATCH] kill nameidata passing to permission(), rename to inode_permission()
Incidentally, the name that gives hundreds of false positives on grep
is not a good idea...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:31 -04:00
Miklos Szeredi
db2e747b14 [patch 5/5] vfs: remove mode parameter from vfs_symlink()
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>
2008-07-26 20:53:18 -04:00
Miklos Szeredi
07cad1d2a4 nfsd: clean up mnt_want_write calls
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>
2008-07-01 15:22:03 -04:00
Miklos Szeredi
8837abcab3 nfsd: rename MAY_ flags
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>
2008-06-23 13:02:50 -04:00
Jeff Layton
ca456252db knfsd: clear both setuid and setgid whenever a chown is done
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>
2008-04-23 16:13:43 -04:00
Jeff Layton
dee3209d99 knfsd: get rid of imode variable in nfsd_setattr
...it's not really needed.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-04-23 16:13:43 -04:00
Harvey Harrison
3ba1514815 nfsd: fix sparse warning in vfs.c
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>
2008-04-23 16:13:39 -04:00
Adrian Bunk
f2b0dee2ec make nfsd_create_setattr() static
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>
2008-04-23 16:13:38 -04:00
Dave Hansen
2c463e9548 [PATCH] r/o bind mounts: check mnt instead of superblock directly
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>
2008-04-19 00:29:27 -04:00
Dave Hansen
18f335aff8 [PATCH] r/o bind mounts: elevate write count for xattr_permission() callers
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>
2008-04-19 00:29:15 -04:00
Dave Hansen
9079b1eb17 [PATCH] r/o bind mounts: get write access for vfs_rename() callers
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>
2008-04-19 00:25:34 -04:00
Dave Hansen
75c3f29de7 [PATCH] r/o bind mounts: write counts for link/symlink
[AV: add missing nfsd pieces]

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: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:25:34 -04:00
Dave Hansen
463c319726 [PATCH] r/o bind mounts: get callers of vfs_mknod/create/mkdir()
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>
2008-04-19 00:25:34 -04:00
Dave Hansen
0622753b80 [PATCH] r/o bind mounts: elevate write count for rmdir and unlink.
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>
2008-04-19 00:25:33 -04:00
Jan Blunck
5477549161 Use struct path in struct svc_export
I'm embedding struct path into struct svc_export.

[akpm@linux-foundation.org: coding-style fixes]
[ezk@cs.sunysb.edu: NFSD: fix wrong mnt_writer count in rename]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:17:08 -08:00
J. Bruce Fields
5c002b3bb2 nfsd: allow root to set uid and gid on create
The server silently ignores attempts to set the uid and gid on create.
Based on the comment, this appears to have been done to prevent some
overly-clever IRIX client from causing itself problems.

Perhaps we should remove that hack completely.  For now, at least, it
makes sense to allow root (when no_root_squash is set) to set uid and
gid.

While we're there, since nfsd_create and nfsd_create_v3 share the same
logic, pull that out into a separate function.  And spell out the
individual modifications of ia_valid instead of doing them both at once
inside a conditional.

Thanks to Roger Willcocks <roger@filmlight.ltd.uk> for the bug report
and original patch on which this is based.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01 16:42:07 -05:00
Chuck Lever
5a022fc870 NFSD: Adjust filename length argument of nfsd_lookup
Clean up: adjust the sign of the length argument of nfsd_lookup and
nfsd_lookup_dentry, for consistency with recent changes.  NFSD version
4 callers already pass an unsigned file name length.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01 16:42:03 -05:00
Pavel Emelyanov
ba25f9dcc4 Use helpers to obtain task pid in printks
The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:43 -07:00
Jeff Layton
8a0ce7d99a knfsd: only set ATTR_KILL_S*ID if ATTR_MODE isn't being explicitly set
It's theoretically possible for a single SETATTR call to come in that sets the
mode and the uid/gid.  In that case, don't set the ATTR_KILL_S*ID bits since
that would trip the BUG() in notify_change.  Just fix up the mode to have the
same effect.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:22 -07:00
Serge E. Hallyn
b53767719b Implement file posix capabilities
Implement file posix capabilities.  This allows programs to be given a
subset of root's powers regardless of who runs them, without having to use
setuid and giving the binary all of root's powers.

This version works with Kaigai Kohei's userspace tools, found at
http://www.kaigai.gr.jp/index.php.  For more information on how to use this
patch, Chris Friedhoff has posted a nice page at
http://www.friedhoff.org/fscaps.html.

Changelog:
	Nov 27:
	Incorporate fixes from Andrew Morton
	(security-introduce-file-caps-tweaks and
	security-introduce-file-caps-warning-fix)
	Fix Kconfig dependency.
	Fix change signaling behavior when file caps are not compiled in.

	Nov 13:
	Integrate comments from Alexey: Remove CONFIG_ ifdef from
	capability.h, and use %zd for printing a size_t.

	Nov 13:
	Fix endianness warnings by sparse as suggested by Alexey
	Dobriyan.

	Nov 09:
	Address warnings of unused variables at cap_bprm_set_security
	when file capabilities are disabled, and simultaneously clean
	up the code a little, by pulling the new code into a helper
	function.

	Nov 08:
	For pointers to required userspace tools and how to use
	them, see http://www.friedhoff.org/fscaps.html.

	Nov 07:
	Fix the calculation of the highest bit checked in
	check_cap_sanity().

	Nov 07:
	Allow file caps to be enabled without CONFIG_SECURITY, since
	capabilities are the default.
	Hook cap_task_setscheduler when !CONFIG_SECURITY.
	Move capable(TASK_KILL) to end of cap_task_kill to reduce
	audit messages.

	Nov 05:
	Add secondary calls in selinux/hooks.c to task_setioprio and
	task_setscheduler so that selinux and capabilities with file
	cap support can be stacked.

	Sep 05:
	As Seth Arnold points out, uid checks are out of place
	for capability code.

	Sep 01:
	Define task_setscheduler, task_setioprio, cap_task_kill, and
	task_setnice to make sure a user cannot affect a process in which
	they called a program with some fscaps.

	One remaining question is the note under task_setscheduler: are we
	ok with CAP_SYS_NICE being sufficient to confine a process to a
	cpuset?

	It is a semantic change, as without fsccaps, attach_task doesn't
	allow CAP_SYS_NICE to override the uid equivalence check.  But since
	it uses security_task_setscheduler, which elsewhere is used where
	CAP_SYS_NICE can be used to override the uid equivalence check,
	fixing it might be tough.

	     task_setscheduler
		 note: this also controls cpuset:attach_task.  Are we ok with
		     CAP_SYS_NICE being used to confine to a cpuset?
	     task_setioprio
	     task_setnice
		 sys_setpriority uses this (through set_one_prio) for another
		 process.  Need same checks as setrlimit

	Aug 21:
	Updated secureexec implementation to reflect the fact that
	euid and uid might be the same and nonzero, but the process
	might still have elevated caps.

	Aug 15:
	Handle endianness of xattrs.
	Enforce capability version match between kernel and disk.
	Enforce that no bits beyond the known max capability are
	set, else return -EPERM.
	With this extra processing, it may be worth reconsidering
	doing all the work at bprm_set_security rather than
	d_instantiate.

	Aug 10:
	Always call getxattr at bprm_set_security, rather than
	caching it at d_instantiate.

[morgan@kernel.org: file-caps clean up for linux/capability.h]
[bunk@kernel.org: unexport cap_inode_killpriv]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Andrew Morgan <morgan@kernel.org>
Signed-off-by: Andrew Morgan <morgan@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:07 -07:00
Dave Hansen
a8754beedb r/o bind mounts: create cleanup helper svc_msnfs()
I'm going to be modifying nfsd_rename() shortly to support read-only bind
mounts.  This #ifdef is around the area I'm patching, and it starts to get
really ugly if I just try to add my new code by itself.  Using this little
helper makes things a lot cleaner to use.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:05 -07:00
Linus Torvalds
541010e4b8 Merge branch 'locks' of git://linux-nfs.org/~bfields/linux
* 'locks' of git://linux-nfs.org/~bfields/linux:
  nfsd: remove IS_ISMNDLCK macro
  Rework /proc/locks via seq_files and seq_list helpers
  fs/locks.c: use list_for_each_entry() instead of list_for_each()
  NFS: clean up explicit check for mandatory locks
  AFS: clean up explicit check for mandatory locks
  9PFS: clean up explicit check for mandatory locks
  GFS2: clean up explicit check for mandatory locks
  Cleanup macros for distinguishing mandatory locks
  Documentation: move locks.txt in filesystems/
  locks: add warning about mandatory locking races
  Documentation: move mandatory locking documentation to filesystems/
  locks: Fix potential OOPS in generic_setlease()
  Use list_first_entry in locks_wake_up_blocks
  locks: fix flock_lock_file() comment
  Memory shortage can result in inconsistent flocks state
  locks: kill redundant local variable
  locks: reverse order of posix_locks_conflict() arguments
2007-10-15 16:07:40 -07:00
J. Bruce Fields
5e7fc43642 nfsd: remove IS_ISMNDLCK macro
This macro is only used in one place; in this place it seems simpler to
put open-code it and move the comment to where it's used.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-10-09 18:32:46 -04:00
Pavel Emelyanov
a16877ca9c Cleanup macros for distinguishing mandatory locks
The combination of S_ISGID bit set and S_IXGRP bit unset is used to mark the
inode as "mandatory lockable" and there's a macro for this check called
MANDATORY_LOCK(inode).  However, fs/locks.c and some filesystems still perform
the explicit i_mode checking.  Besides, Andrew pointed out, that this macro is
buggy itself, as it dereferences the inode arg twice.

Convert this macro into static inline function and switch its users to it,
making the code shorter and more readable.

The __mandatory_lock() helper is to be used in places where the IS_MANDLOCK()
for superblock is already known to be true.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-10-09 18:32:46 -04:00
Christoph Hellwig
9c85fca56b nfsd: fix horrible indentation in nfsd_setattr
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by:  Neil Brown <neilb@suse.de>
2007-10-09 18:31:56 -04:00