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remarkable-linux/fs/nfsd/nfsfh.c
David Howells d84f4f992c CRED: Inaugurate COW credentials 
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>
2008-11-14 10:39:23 +11:00

650 lines
16 KiB
C
Raw Blame History

/*
* linux/fs/nfsd/nfsfh.c
*
* NFS server file handle treatment.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
* Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
* Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
* ... and again Southern-Winter 2001 to support export_operations
*/
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/dcache.h>
#include <linux/exportfs.h>
#include <linux/mount.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/nfsd/nfsd.h>
#include "auth.h"
#define NFSDDBG_FACILITY NFSDDBG_FH
static int nfsd_nr_verified;
static int nfsd_nr_put;
/*
* our acceptability function.
* if NOSUBTREECHECK, accept anything
* if not, require that we can walk up to exp->ex_dentry
* doing some checks on the 'x' bits
*/
static int nfsd_acceptable(void *expv, struct dentry *dentry)
{
struct svc_export *exp = expv;
int rv;
struct dentry *tdentry;
struct dentry *parent;
if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
return 1;
tdentry = dget(dentry);
while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
/* make sure parents give x permission to user */
int err;
parent = dget_parent(tdentry);
err = inode_permission(parent->d_inode, MAY_EXEC);
if (err < 0) {
dput(parent);
break;
}
dput(tdentry);
tdentry = parent;
}
if (tdentry != exp->ex_path.dentry)
dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
rv = (tdentry == exp->ex_path.dentry);
dput(tdentry);
return rv;
}
/* Type check. The correct error return for type mismatches does not seem to be
* generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
* comment in the NFSv3 spec says this is incorrect (implementation notes for
* the write call).
*/
static inline __be32
nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
{
/* Type can be negative when creating hardlinks - not to a dir */
if (type > 0 && (mode & S_IFMT) != type) {
if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
return nfserr_symlink;
else if (type == S_IFDIR)
return nfserr_notdir;
else if ((mode & S_IFMT) == S_IFDIR)
return nfserr_isdir;
else
return nfserr_inval;
}
if (type < 0 && (mode & S_IFMT) == -type) {
if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
return nfserr_symlink;
else if (type == -S_IFDIR)
return nfserr_isdir;
else
return nfserr_notdir;
}
return 0;
}
static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
struct svc_export *exp)
{
/* Check if the request originated from a secure port. */
if (!rqstp->rq_secure && EX_SECURE(exp)) {
RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
dprintk(KERN_WARNING
"nfsd: request from insecure port %s!\n",
svc_print_addr(rqstp, buf, sizeof(buf)));
return nfserr_perm;
}
/* Set user creds for this exportpoint */
return nfserrno(nfsd_setuser(rqstp, exp));
}
/*
* Use the given filehandle to look up the corresponding export and
* dentry. On success, the results are used to set fh_export and
* fh_dentry.
*/
static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
{
struct knfsd_fh *fh = &fhp->fh_handle;
struct fid *fid = NULL, sfid;
struct svc_export *exp;
struct dentry *dentry;
int fileid_type;
int data_left = fh->fh_size/4;
__be32 error;
error = nfserr_stale;
if (rqstp->rq_vers > 2)
error = nfserr_badhandle;
if (rqstp->rq_vers == 4 && fh->fh_size == 0)
return nfserr_nofilehandle;
if (fh->fh_version == 1) {
int len;
if (--data_left < 0)
return error;
if (fh->fh_auth_type != 0)
return error;
len = key_len(fh->fh_fsid_type) / 4;
if (len == 0)
return error;
if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
/* deprecated, convert to type 3 */
len = key_len(FSID_ENCODE_DEV)/4;
fh->fh_fsid_type = FSID_ENCODE_DEV;
fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
fh->fh_fsid[1] = fh->fh_fsid[2];
}
data_left -= len;
if (data_left < 0)
return error;
exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
fid = (struct fid *)(fh->fh_auth + len);
} else {
__u32 tfh[2];
dev_t xdev;
ino_t xino;
if (fh->fh_size != NFS_FHSIZE)
return error;
/* assume old filehandle format */
xdev = old_decode_dev(fh->ofh_xdev);
xino = u32_to_ino_t(fh->ofh_xino);
mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
}
error = nfserr_stale;
if (PTR_ERR(exp) == -ENOENT)
return error;
if (IS_ERR(exp))
return nfserrno(PTR_ERR(exp));
if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
/* Elevate privileges so that the lack of 'r' or 'x'
* permission on some parent directory will
* not stop exportfs_decode_fh from being able
* to reconnect a directory into the dentry cache.
* The same problem can affect "SUBTREECHECK" exports,
* but as nfsd_acceptable depends on correct
* access control settings being in effect, we cannot
* fix that case easily.
*/
struct cred *new = prepare_creds();
if (!new)
return nfserrno(-ENOMEM);
new->cap_effective =
cap_raise_nfsd_set(new->cap_effective,
new->cap_permitted);
put_cred(override_creds(new));
put_cred(new);
} else {
error = nfsd_setuser_and_check_port(rqstp, exp);
if (error)
goto out;
}
/*
* Look up the dentry using the NFS file handle.
*/
error = nfserr_stale;
if (rqstp->rq_vers > 2)
error = nfserr_badhandle;
if (fh->fh_version != 1) {
sfid.i32.ino = fh->ofh_ino;
sfid.i32.gen = fh->ofh_generation;
sfid.i32.parent_ino = fh->ofh_dirino;
fid = &sfid;
data_left = 3;
if (fh->ofh_dirino == 0)
fileid_type = FILEID_INO32_GEN;
else
fileid_type = FILEID_INO32_GEN_PARENT;
} else
fileid_type = fh->fh_fileid_type;
if (fileid_type == FILEID_ROOT)
dentry = dget(exp->ex_path.dentry);
else {
dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
data_left, fileid_type,
nfsd_acceptable, exp);
}
if (dentry == NULL)
goto out;
if (IS_ERR(dentry)) {
if (PTR_ERR(dentry) != -EINVAL)
error = nfserrno(PTR_ERR(dentry));
goto out;
}
if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
error = nfsd_setuser_and_check_port(rqstp, exp);
if (error) {
dput(dentry);
goto out;
}
}
if (S_ISDIR(dentry->d_inode->i_mode) &&
(dentry->d_flags & DCACHE_DISCONNECTED)) {
printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
}
fhp->fh_dentry = dentry;
fhp->fh_export = exp;
nfsd_nr_verified++;
return 0;
out:
exp_put(exp);
return error;
}
/*
* Perform sanity checks on the dentry in a client's file handle.
*
* Note that the file handle dentry may need to be freed even after
* an error return.
*
* This is only called at the start of an nfsproc call, so fhp points to
* a svc_fh which is all 0 except for the over-the-wire file handle.
*/
__be32
fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
{
struct svc_export *exp;
struct dentry *dentry;
__be32 error;
dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
if (!fhp->fh_dentry) {
error = nfsd_set_fh_dentry(rqstp, fhp);
if (error)
goto out;
dentry = fhp->fh_dentry;
exp = fhp->fh_export;
} else {
/*
* just rechecking permissions
* (e.g. nfsproc_create calls fh_verify, then nfsd_create
* does as well)
*/
dprintk("nfsd: fh_verify - just checking\n");
dentry = fhp->fh_dentry;
exp = fhp->fh_export;
/*
* Set user creds for this exportpoint; necessary even
* in the "just checking" case because this may be a
* filehandle that was created by fh_compose, and that
* is about to be used in another nfsv4 compound
* operation.
*/
error = nfsd_setuser_and_check_port(rqstp, exp);
if (error)
goto out;
}
error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
if (error)
goto out;
/*
* pseudoflavor restrictions are not enforced on NLM,
* which clients virtually always use auth_sys for,
* even while using RPCSEC_GSS for NFS.
*/
if (access & NFSD_MAY_LOCK)
goto skip_pseudoflavor_check;
/*
* Clients may expect to be able to use auth_sys during mount,
* even if they use gss for everything else; see section 2.3.2
* of rfc 2623.
*/
if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
&& exp->ex_path.dentry == dentry)
goto skip_pseudoflavor_check;
error = check_nfsd_access(exp, rqstp);
if (error)
goto out;
skip_pseudoflavor_check:
/* Finally, check access permissions. */
error = nfsd_permission(rqstp, exp, dentry, access);
if (error) {
dprintk("fh_verify: %s/%s permission failure, "
"acc=%x, error=%d\n",
dentry->d_parent->d_name.name,
dentry->d_name.name,
access, ntohl(error));
}
out:
if (error == nfserr_stale)
nfsdstats.fh_stale++;
return error;
}
/*
* Compose a file handle for an NFS reply.
*
* Note that when first composed, the dentry may not yet have
* an inode. In this case a call to fh_update should be made
* before the fh goes out on the wire ...
*/
static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
struct dentry *dentry)
{
if (dentry != exp->ex_path.dentry) {
struct fid *fid = (struct fid *)
(fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
fhp->fh_handle.fh_fileid_type =
exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
fhp->fh_handle.fh_size += maxsize * 4;
} else {
fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
}
}
/*
* for composing old style file handles
*/
static inline void _fh_update_old(struct dentry *dentry,
struct svc_export *exp,
struct knfsd_fh *fh)
{
fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
fh->ofh_generation = dentry->d_inode->i_generation;
if (S_ISDIR(dentry->d_inode->i_mode) ||
(exp->ex_flags & NFSEXP_NOSUBTREECHECK))
fh->ofh_dirino = 0;
}
__be32
fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
struct svc_fh *ref_fh)
{
/* ref_fh is a reference file handle.
* if it is non-null and for the same filesystem, then we should compose
* a filehandle which is of the same version, where possible.
* Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
* Then create a 32byte filehandle using nfs_fhbase_old
*
*/
u8 version;
u8 fsid_type = 0;
struct inode * inode = dentry->d_inode;
struct dentry *parent = dentry->d_parent;
__u32 *datap;
dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
MAJOR(ex_dev), MINOR(ex_dev),
(long) exp->ex_path.dentry->d_inode->i_ino,
parent->d_name.name, dentry->d_name.name,
(inode ? inode->i_ino : 0));
/* Choose filehandle version and fsid type based on
* the reference filehandle (if it is in the same export)
* or the export options.
*/
retry:
version = 1;
if (ref_fh && ref_fh->fh_export == exp) {
version = ref_fh->fh_handle.fh_version;
fsid_type = ref_fh->fh_handle.fh_fsid_type;
if (ref_fh == fhp)
fh_put(ref_fh);
ref_fh = NULL;
switch (version) {
case 0xca:
fsid_type = FSID_DEV;
break;
case 1:
break;
default:
goto retry;
}
/* Need to check that this type works for this
* export point. As the fsid -> filesystem mapping
* was guided by user-space, there is no guarantee
* that the filesystem actually supports that fsid
* type. If it doesn't we loop around again without
* ref_fh set.
*/
switch(fsid_type) {
case FSID_DEV:
if (!old_valid_dev(ex_dev))
goto retry;
/* FALL THROUGH */
case FSID_MAJOR_MINOR:
case FSID_ENCODE_DEV:
if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
& FS_REQUIRES_DEV))
goto retry;
break;
case FSID_NUM:
if (! (exp->ex_flags & NFSEXP_FSID))
goto retry;
break;
case FSID_UUID8:
case FSID_UUID16:
if (!root_export)
goto retry;
/* fall through */
case FSID_UUID4_INUM:
case FSID_UUID16_INUM:
if (exp->ex_uuid == NULL)
goto retry;
break;
}
} else if (exp->ex_uuid) {
if (fhp->fh_maxsize >= 64) {
if (root_export)
fsid_type = FSID_UUID16;
else
fsid_type = FSID_UUID16_INUM;
} else {
if (root_export)
fsid_type = FSID_UUID8;
else
fsid_type = FSID_UUID4_INUM;
}
} else if (exp->ex_flags & NFSEXP_FSID)
fsid_type = FSID_NUM;
else if (!old_valid_dev(ex_dev))
/* for newer device numbers, we must use a newer fsid format */
fsid_type = FSID_ENCODE_DEV;
else
fsid_type = FSID_DEV;
if (ref_fh == fhp)
fh_put(ref_fh);
if (fhp->fh_locked || fhp->fh_dentry) {
printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
parent->d_name.name, dentry->d_name.name);
}
if (fhp->fh_maxsize < NFS_FHSIZE)
printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
fhp->fh_maxsize,
parent->d_name.name, dentry->d_name.name);
fhp->fh_dentry = dget(dentry); /* our internal copy */
fhp->fh_export = exp;
cache_get(&exp->h);
if (version == 0xca) {
/* old style filehandle please */
memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
fhp->fh_handle.fh_size = NFS_FHSIZE;
fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
fhp->fh_handle.ofh_xino =
ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
if (inode)
_fh_update_old(dentry, exp, &fhp->fh_handle);
} else {
int len;
fhp->fh_handle.fh_version = 1;
fhp->fh_handle.fh_auth_type = 0;
datap = fhp->fh_handle.fh_auth+0;
fhp->fh_handle.fh_fsid_type = fsid_type;
mk_fsid(fsid_type, datap, ex_dev,
exp->ex_path.dentry->d_inode->i_ino,
exp->ex_fsid, exp->ex_uuid);
len = key_len(fsid_type);
datap += len/4;
fhp->fh_handle.fh_size = 4 + len;
if (inode)
_fh_update(fhp, exp, dentry);
if (fhp->fh_handle.fh_fileid_type == 255)
return nfserr_opnotsupp;
}
nfsd_nr_verified++;
return 0;
}
/*
* Update file handle information after changing a dentry.
* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
*/
__be32
fh_update(struct svc_fh *fhp)
{
struct dentry *dentry;
if (!fhp->fh_dentry)
goto out_bad;
dentry = fhp->fh_dentry;
if (!dentry->d_inode)
goto out_negative;
if (fhp->fh_handle.fh_version != 1) {
_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
} else {
if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
goto out;
_fh_update(fhp, fhp->fh_export, dentry);
if (fhp->fh_handle.fh_fileid_type == 255)
return nfserr_opnotsupp;
}
out:
return 0;
out_bad:
printk(KERN_ERR "fh_update: fh not verified!\n");
goto out;
out_negative:
printk(KERN_ERR "fh_update: %s/%s still negative!\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
goto out;
}
/*
* Release a file handle.
*/
void
fh_put(struct svc_fh *fhp)
{
struct dentry * dentry = fhp->fh_dentry;
struct svc_export * exp = fhp->fh_export;
if (dentry) {
fh_unlock(fhp);
fhp->fh_dentry = NULL;
dput(dentry);
#ifdef CONFIG_NFSD_V3
fhp->fh_pre_saved = 0;
fhp->fh_post_saved = 0;
#endif
nfsd_nr_put++;
}
if (exp) {
cache_put(&exp->h, &svc_export_cache);
fhp->fh_export = NULL;
}
return;
}
/*
* Shorthand for dprintk()'s
*/
char * SVCFH_fmt(struct svc_fh *fhp)
{
struct knfsd_fh *fh = &fhp->fh_handle;
static char buf[80];
sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
fh->fh_size,
fh->fh_base.fh_pad[0],
fh->fh_base.fh_pad[1],
fh->fh_base.fh_pad[2],
fh->fh_base.fh_pad[3],
fh->fh_base.fh_pad[4],
fh->fh_base.fh_pad[5]);
return buf;
}
enum fsid_source fsid_source(struct svc_fh *fhp)
{
if (fhp->fh_handle.fh_version != 1)
return FSIDSOURCE_DEV;
switch(fhp->fh_handle.fh_fsid_type) {
case FSID_DEV:
case FSID_ENCODE_DEV:
case FSID_MAJOR_MINOR:
if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
& FS_REQUIRES_DEV)
return FSIDSOURCE_DEV;
break;
case FSID_NUM:
if (fhp->fh_export->ex_flags & NFSEXP_FSID)
return FSIDSOURCE_FSID;
break;
default:
break;
}
/* either a UUID type filehandle, or the filehandle doesn't
* match the export.
*/
if (fhp->fh_export->ex_flags & NFSEXP_FSID)
return FSIDSOURCE_FSID;
if (fhp->fh_export->ex_uuid)
return FSIDSOURCE_UUID;
return FSIDSOURCE_DEV;
}
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