![NeilBrown](/assets/img/avatar_default.png)
.. it makes some of the code nicer. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
533 lines
14 KiB
C
533 lines
14 KiB
C
/*
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* linux/fs/nfsd/nfsfh.c
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*
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* NFS server file handle treatment.
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*
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* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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* Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
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* Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
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* ... and again Southern-Winter 2001 to support export_operations
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*/
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/smp_lock.h>
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#include <linux/fs.h>
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#include <linux/unistd.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/dcache.h>
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#include <linux/mount.h>
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#include <asm/pgtable.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/nfsd/nfsd.h>
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#define NFSDDBG_FACILITY NFSDDBG_FH
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#define NFSD_PARANOIA 1
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/* #define NFSD_DEBUG_VERBOSE 1 */
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static int nfsd_nr_verified;
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static int nfsd_nr_put;
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extern struct export_operations export_op_default;
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#define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)
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/*
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* our acceptability function.
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* if NOSUBTREECHECK, accept anything
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* if not, require that we can walk up to exp->ex_dentry
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* doing some checks on the 'x' bits
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*/
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static int nfsd_acceptable(void *expv, struct dentry *dentry)
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{
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struct svc_export *exp = expv;
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int rv;
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struct dentry *tdentry;
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struct dentry *parent;
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if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
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return 1;
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tdentry = dget(dentry);
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while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
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/* make sure parents give x permission to user */
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int err;
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parent = dget_parent(tdentry);
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err = permission(parent->d_inode, MAY_EXEC, NULL);
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if (err < 0) {
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dput(parent);
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break;
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}
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dput(tdentry);
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tdentry = parent;
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}
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if (tdentry != exp->ex_dentry)
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dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
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rv = (tdentry == exp->ex_dentry);
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dput(tdentry);
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return rv;
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}
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/* Type check. The correct error return for type mismatches does not seem to be
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* generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
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* comment in the NFSv3 spec says this is incorrect (implementation notes for
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* the write call).
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*/
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static inline int
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nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
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{
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/* Type can be negative when creating hardlinks - not to a dir */
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if (type > 0 && (mode & S_IFMT) != type) {
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if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
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return nfserr_symlink;
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else if (type == S_IFDIR)
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return nfserr_notdir;
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else if ((mode & S_IFMT) == S_IFDIR)
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return nfserr_isdir;
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else
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return nfserr_inval;
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}
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if (type < 0 && (mode & S_IFMT) == -type) {
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if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
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return nfserr_symlink;
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else if (type == -S_IFDIR)
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return nfserr_isdir;
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else
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return nfserr_notdir;
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}
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return 0;
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}
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/*
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* Perform sanity checks on the dentry in a client's file handle.
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*
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* Note that the file handle dentry may need to be freed even after
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* an error return.
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*
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* This is only called at the start of an nfsproc call, so fhp points to
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* a svc_fh which is all 0 except for the over-the-wire file handle.
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*/
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u32
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fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
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{
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struct knfsd_fh *fh = &fhp->fh_handle;
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struct svc_export *exp = NULL;
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struct dentry *dentry;
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u32 error = 0;
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dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
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/* keep this filehandle for possible reference when encoding attributes */
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rqstp->rq_reffh = fh;
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if (!fhp->fh_dentry) {
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__u32 *datap=NULL;
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__u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */
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int fileid_type;
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int data_left = fh->fh_size/4;
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error = nfserr_stale;
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if (rqstp->rq_client == NULL)
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goto out;
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if (rqstp->rq_vers > 2)
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error = nfserr_badhandle;
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if (rqstp->rq_vers == 4 && fh->fh_size == 0)
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return nfserr_nofilehandle;
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if (fh->fh_version == 1) {
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int len;
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datap = fh->fh_auth;
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if (--data_left<0) goto out;
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switch (fh->fh_auth_type) {
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case 0: break;
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default: goto out;
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}
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len = key_len(fh->fh_fsid_type) / 4;
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if (len == 0) goto out;
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if (fh->fh_fsid_type == 2) {
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/* deprecated, convert to type 3 */
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len = 3;
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fh->fh_fsid_type = 3;
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fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
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fh->fh_fsid[1] = fh->fh_fsid[2];
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}
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if ((data_left -= len)<0) goto out;
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exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
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datap += len;
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} else {
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dev_t xdev;
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ino_t xino;
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if (fh->fh_size != NFS_FHSIZE)
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goto out;
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/* assume old filehandle format */
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xdev = old_decode_dev(fh->ofh_xdev);
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xino = u32_to_ino_t(fh->ofh_xino);
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mk_fsid_v0(tfh, xdev, xino);
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exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle);
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}
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error = nfserr_dropit;
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if (IS_ERR(exp) && PTR_ERR(exp) == -EAGAIN)
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goto out;
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error = nfserr_stale;
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if (!exp || IS_ERR(exp))
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goto out;
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/* Check if the request originated from a secure port. */
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error = nfserr_perm;
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if (!rqstp->rq_secure && EX_SECURE(exp)) {
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printk(KERN_WARNING
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"nfsd: request from insecure port (%u.%u.%u.%u:%d)!\n",
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NIPQUAD(rqstp->rq_addr.sin_addr.s_addr),
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ntohs(rqstp->rq_addr.sin_port));
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goto out;
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}
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/* Set user creds for this exportpoint */
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error = nfsd_setuser(rqstp, exp);
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if (error) {
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error = nfserrno(error);
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goto out;
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}
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/*
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* Look up the dentry using the NFS file handle.
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*/
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error = nfserr_stale;
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if (rqstp->rq_vers > 2)
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error = nfserr_badhandle;
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if (fh->fh_version != 1) {
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tfh[0] = fh->ofh_ino;
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tfh[1] = fh->ofh_generation;
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tfh[2] = fh->ofh_dirino;
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datap = tfh;
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data_left = 3;
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if (fh->ofh_dirino == 0)
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fileid_type = 1;
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else
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fileid_type = 2;
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} else
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fileid_type = fh->fh_fileid_type;
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if (fileid_type == 0)
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dentry = dget(exp->ex_dentry);
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else {
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struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
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dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
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datap, data_left,
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fileid_type,
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nfsd_acceptable, exp);
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}
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if (dentry == NULL)
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goto out;
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if (IS_ERR(dentry)) {
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if (PTR_ERR(dentry) != -EINVAL)
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error = nfserrno(PTR_ERR(dentry));
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goto out;
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}
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#ifdef NFSD_PARANOIA
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if (S_ISDIR(dentry->d_inode->i_mode) &&
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(dentry->d_flags & DCACHE_DISCONNECTED)) {
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printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
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dentry->d_parent->d_name.name, dentry->d_name.name);
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}
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#endif
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fhp->fh_dentry = dentry;
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fhp->fh_export = exp;
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nfsd_nr_verified++;
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} else {
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/* just rechecking permissions
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* (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
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*/
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dprintk("nfsd: fh_verify - just checking\n");
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dentry = fhp->fh_dentry;
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exp = fhp->fh_export;
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}
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cache_get(&exp->h);
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error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
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if (error)
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goto out;
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/* Finally, check access permissions. */
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error = nfsd_permission(exp, dentry, access);
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#ifdef NFSD_PARANOIA_EXTREME
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if (error) {
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printk("fh_verify: %s/%s permission failure, acc=%x, error=%d\n",
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dentry->d_parent->d_name.name, dentry->d_name.name, access, (error >> 24));
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}
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#endif
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out:
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if (exp && !IS_ERR(exp))
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exp_put(exp);
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if (error == nfserr_stale)
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nfsdstats.fh_stale++;
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return error;
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}
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/*
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* Compose a file handle for an NFS reply.
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*
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* Note that when first composed, the dentry may not yet have
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* an inode. In this case a call to fh_update should be made
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* before the fh goes out on the wire ...
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*/
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static inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
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__u32 *datap, int *maxsize)
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{
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struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
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if (dentry == exp->ex_dentry) {
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*maxsize = 0;
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return 0;
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}
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return CALL(nop,encode_fh)(dentry, datap, maxsize,
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!(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
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}
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/*
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* for composing old style file handles
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*/
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static inline void _fh_update_old(struct dentry *dentry,
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struct svc_export *exp,
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struct knfsd_fh *fh)
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{
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fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
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fh->ofh_generation = dentry->d_inode->i_generation;
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if (S_ISDIR(dentry->d_inode->i_mode) ||
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(exp->ex_flags & NFSEXP_NOSUBTREECHECK))
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fh->ofh_dirino = 0;
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}
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int
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fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry, struct svc_fh *ref_fh)
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{
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/* ref_fh is a reference file handle.
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* if it is non-null, then we should compose a filehandle which is
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* of the same version, where possible.
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* Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
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* Then create a 32byte filehandle using nfs_fhbase_old
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*
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*/
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u8 ref_fh_version = 0;
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u8 ref_fh_fsid_type = 0;
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struct inode * inode = dentry->d_inode;
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struct dentry *parent = dentry->d_parent;
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__u32 *datap;
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dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
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dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
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MAJOR(ex_dev), MINOR(ex_dev),
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(long) exp->ex_dentry->d_inode->i_ino,
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parent->d_name.name, dentry->d_name.name,
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(inode ? inode->i_ino : 0));
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if (ref_fh) {
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ref_fh_version = ref_fh->fh_handle.fh_version;
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if (ref_fh_version == 0xca)
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ref_fh_fsid_type = 0;
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else
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ref_fh_fsid_type = ref_fh->fh_handle.fh_fsid_type;
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if (ref_fh_fsid_type > 3)
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ref_fh_fsid_type = 0;
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/* make sure ref_fh type works for given export */
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if (ref_fh_fsid_type == 1 &&
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!(exp->ex_flags & NFSEXP_FSID)) {
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/* if we don't have an fsid, we cannot provide one... */
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ref_fh_fsid_type = 0;
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}
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} else if (exp->ex_flags & NFSEXP_FSID)
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ref_fh_fsid_type = 1;
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if (!old_valid_dev(ex_dev) && ref_fh_fsid_type == 0) {
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/* for newer device numbers, we must use a newer fsid format */
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ref_fh_version = 1;
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ref_fh_fsid_type = 3;
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}
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if (old_valid_dev(ex_dev) &&
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(ref_fh_fsid_type == 2 || ref_fh_fsid_type == 3))
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/* must use type1 for smaller device numbers */
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ref_fh_fsid_type = 0;
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if (ref_fh == fhp)
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fh_put(ref_fh);
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if (fhp->fh_locked || fhp->fh_dentry) {
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printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
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parent->d_name.name, dentry->d_name.name);
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}
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if (fhp->fh_maxsize < NFS_FHSIZE)
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printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
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fhp->fh_maxsize, parent->d_name.name, dentry->d_name.name);
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fhp->fh_dentry = dget(dentry); /* our internal copy */
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fhp->fh_export = exp;
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cache_get(&exp->h);
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if (ref_fh_version == 0xca) {
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/* old style filehandle please */
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memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
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fhp->fh_handle.fh_size = NFS_FHSIZE;
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fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
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fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
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fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
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fhp->fh_handle.ofh_xino = ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
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fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
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if (inode)
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_fh_update_old(dentry, exp, &fhp->fh_handle);
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} else {
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int len;
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fhp->fh_handle.fh_version = 1;
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fhp->fh_handle.fh_auth_type = 0;
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datap = fhp->fh_handle.fh_auth+0;
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fhp->fh_handle.fh_fsid_type = ref_fh_fsid_type;
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switch (ref_fh_fsid_type) {
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case 0:
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/*
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* fsid_type 0:
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* 2byte major, 2byte minor, 4byte inode
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*/
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mk_fsid_v0(datap, ex_dev,
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exp->ex_dentry->d_inode->i_ino);
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break;
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case 1:
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/* fsid_type 1 == 4 bytes filesystem id */
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mk_fsid_v1(datap, exp->ex_fsid);
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break;
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case 2:
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/*
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* fsid_type 2:
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* 4byte major, 4byte minor, 4byte inode
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*/
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mk_fsid_v2(datap, ex_dev,
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exp->ex_dentry->d_inode->i_ino);
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break;
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case 3:
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/*
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* fsid_type 3:
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* 4byte devicenumber, 4byte inode
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*/
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mk_fsid_v3(datap, ex_dev,
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exp->ex_dentry->d_inode->i_ino);
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break;
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}
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len = key_len(ref_fh_fsid_type);
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datap += len/4;
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fhp->fh_handle.fh_size = 4 + len;
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if (inode) {
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int size = (fhp->fh_maxsize-len-4)/4;
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fhp->fh_handle.fh_fileid_type =
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_fh_update(dentry, exp, datap, &size);
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fhp->fh_handle.fh_size += size*4;
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}
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if (fhp->fh_handle.fh_fileid_type == 255)
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return nfserr_opnotsupp;
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}
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nfsd_nr_verified++;
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return 0;
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}
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/*
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* Update file handle information after changing a dentry.
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* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
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*/
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int
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fh_update(struct svc_fh *fhp)
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{
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struct dentry *dentry;
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__u32 *datap;
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if (!fhp->fh_dentry)
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goto out_bad;
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dentry = fhp->fh_dentry;
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if (!dentry->d_inode)
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goto out_negative;
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if (fhp->fh_handle.fh_version != 1) {
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_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
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} else {
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int size;
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if (fhp->fh_handle.fh_fileid_type != 0)
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goto out_uptodate;
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datap = fhp->fh_handle.fh_auth+
|
|
fhp->fh_handle.fh_size/4 -1;
|
|
size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
|
|
fhp->fh_handle.fh_fileid_type =
|
|
_fh_update(dentry, fhp->fh_export, datap, &size);
|
|
fhp->fh_handle.fh_size += size*4;
|
|
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;
|
|
out_uptodate:
|
|
printk(KERN_ERR "fh_update: %s/%s already up-to-date!\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;
|
|
}
|