static __be32
compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
const char *name, int namlen, u64 ino)
{
struct svc_export *exp;
struct dentry *dparent, *dchild;
__be32 rv = nfserr_noent;
dparent = cd->fh.fh_dentry;
exp = cd->fh.fh_export;
if (isdotent(name, namlen)) {
if (namlen == 2) {
dchild = dget_parent(dparent);
/* filesystem root - cannot return filehandle for ".." */
if (dchild == dparent)
goto out;
} else
dchild = dget(dparent);
} else
dchild = lookup_one_len_unlocked(name, dparent, namlen);
if (IS_ERR(dchild))
return rv;
if (d_mountpoint(dchild))
goto out;
if (d_really_is_negative(dchild))
goto out;
if (dchild->d_inode->i_ino != ino)
goto out;
rv = fh_compose(fhp, exp, dchild, &cd->fh);
out:
dput(dchild);
return rv;
}
static int
nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct dentry_list_arg *dla = arg;
struct list_head *dentries = &dla->dentries;
struct dentry *parent = dla->parent;
struct dentry *dentry;
struct dentry_list *child;
if (name && isdotent(name, namlen))
return 0;
dentry = lookup_one_len(name, parent, namlen);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
child = kmalloc(sizeof(*child), GFP_KERNEL);
if (child == NULL)
return -ENOMEM;
child->dentry = dentry;
list_add(&child->list, dentries);
return 0;
}
static int
encode_entry(struct readdir_cd *cd, const char *name,
int namlen, off_t offset, ino_t ino, unsigned int d_type, int plus)
{
u32 *p = cd->buffer;
int buflen, slen, elen;
if (cd->offset)
xdr_encode_hyper(cd->offset, (u64) offset);
/* nfsd_readdir calls us with name == 0 when it wants us to
* set the last offset entry. */
if (name == 0)
return 0;
/*
dprintk("encode_entry(%.*s @%ld%s)\n",
namlen, name, (long) offset, plus? " plus" : "");
*/
/* truncate filename if too long */
if (namlen > NFS3_MAXNAMLEN)
namlen = NFS3_MAXNAMLEN;
slen = XDR_QUADLEN(namlen);
elen = slen + NFS3_ENTRY_BAGGAGE
+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
if ((buflen = cd->buflen - elen) < 0) {
cd->eob = 1;
return -EINVAL;
}
*p++ = xdr_one; /* mark entry present */
p = xdr_encode_hyper(p, ino); /* file id */
p = xdr_encode_array(p, name, namlen);/* name length & name */
cd->offset = p; /* remember pointer */
p = xdr_encode_hyper(p, NFS_OFFSET_MAX); /* offset of next entry */
/* throw in readdirplus baggage */
if (plus) {
struct svc_fh fh;
struct svc_export *exp;
struct dentry *dparent, *dchild;
dparent = cd->dirfh->fh_dentry;
exp = cd->dirfh->fh_export;
fh_init(&fh, NFS3_FHSIZE);
if (isdotent(name, namlen)) {
dchild = dparent;
if (namlen == 2)
dchild = dchild->d_parent;
dchild = dget(dchild);
} else
dchild = lookup_one_len(name, dparent,namlen);
if (IS_ERR(dchild))
goto noexec;
if (fh_compose(&fh, exp, dchild, cd->dirfh) != 0 || !dchild->d_inode)
goto noexec;
p = encode_post_op_attr(cd->rqstp, p, &fh);
*p++ = xdr_one; /* yes, a file handle follows */
p = encode_fh(p, &fh);
fh_put(&fh);
}
out:
cd->buflen = buflen;
cd->buffer = p;
return 0;
noexec:
*p++ = 0;
*p++ = 0;
goto out;
}
__be32
nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
const char *name, unsigned int len,
struct svc_export **exp_ret, struct dentry **dentry_ret)
{
struct svc_export *exp;
struct dentry *dparent;
struct dentry *dentry;
__be32 err;
int host_err;
dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
/* Obtain dentry and export. */
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
if (err)
return err;
dparent = fhp->fh_dentry;
exp = fhp->fh_export;
exp_get(exp);
/* Lookup the name, but don't follow links */
if (isdotent(name, len)) {
if (len==1)
dentry = dget(dparent);
else if (dparent != exp->ex_path.dentry)
dentry = dget_parent(dparent);
else if (!EX_NOHIDE(exp))
dentry = dget(dparent); /* .. == . just like at / */
else {
/* checking mountpoint crossing is very different when stepping up */
struct svc_export *exp2 = NULL;
struct dentry *dp;
struct vfsmount *mnt = mntget(exp->ex_path.mnt);
dentry = dget(dparent);
while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
;
dp = dget_parent(dentry);
dput(dentry);
dentry = dp;
exp2 = rqst_exp_parent(rqstp, mnt, dentry);
if (PTR_ERR(exp2) == -ENOENT) {
dput(dentry);
dentry = dget(dparent);
} else if (IS_ERR(exp2)) {
host_err = PTR_ERR(exp2);
dput(dentry);
mntput(mnt);
goto out_nfserr;
} else {
exp_put(exp);
exp = exp2;
}
mntput(mnt);
}
} else {
fh_lock(fhp);
dentry = lookup_one_len(name, dparent, len);
host_err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_nfserr;
/*
* check if we have crossed a mount point ...
*/
if (d_mountpoint(dentry)) {
if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
dput(dentry);
goto out_nfserr;
}
}
}
*dentry_ret = dentry;
*exp_ret = exp;
return 0;
out_nfserr:
exp_put(exp);
return nfserrno(host_err);
}
/*
* Look up one component of a pathname.
* N.B. After this call _both_ fhp and resfh need an fh_put
*
* If the lookup would cross a mountpoint, and the mounted filesystem
* is exported to the client with NFSEXP_CROSSMNT, then the lookup is
* accepted as it stands and the mounted directory is
* returned. Otherwise the covered directory is returned.
* NOTE: this mountpoint crossing is not supported properly by all
* clients and is explicitly disallowed for NFSv3
* NeilBrown <*****@*****.**>
*/
int
nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
int len, struct svc_fh *resfh)
{
struct svc_export *exp;
struct dentry *dparent;
struct dentry *dentry;
int err;
dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
/* Obtain dentry and export. */
err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
if (err)
goto out;
dparent = fhp->fh_dentry;
exp = fhp->fh_export;
err = nfserr_acces;
/* Lookup the name, but don't follow links */
if (isdotent(name, len)) {
if (len==1)
dentry = dget(dparent);
else { /* must be ".." */
/* checking mountpoint crossing is very different when stepping up */
if (dparent == exp->ex_dentry) {
if (!EX_CROSSMNT(exp))
dentry = dget(dparent); /* .. == . just like at / */
else
{
struct svc_export *exp2 = NULL;
struct dentry *dp;
struct vfsmount *mnt = mntget(exp->ex_mnt);
dentry = dget(dparent);
while(follow_up(&mnt, &dentry))
;
dp = dget(dentry->d_parent);
dput(dentry);
dentry = dp;
for ( ; exp2 == NULL && dp->d_parent != dp;
dp=dp->d_parent)
exp2 = exp_get(exp->ex_client, dp->d_inode->i_dev, dp->d_inode->i_ino);
if (exp2==NULL) {
dput(dentry);
dentry = dget(dparent);
} else {
exp = exp2;
}
mntput(mnt);
}
} else
dentry = dget(dparent->d_parent);
}
} else {
fh_lock(fhp);
dentry = lookup_one_len(name, dparent, len);
err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_nfserr;
/*
* check if we have crossed a mount point ...
*/
if (d_mountpoint(dentry)) {
struct svc_export *exp2 = NULL;
struct vfsmount *mnt = mntget(exp->ex_mnt);
struct dentry *mounts = dget(dentry);
while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts))
;
exp2 = exp_get(rqstp->rq_client,
mounts->d_inode->i_dev,
mounts->d_inode->i_ino);
if (exp2 && EX_CROSSMNT(exp2)) {
/* successfully crossed mount point */
exp = exp2;
dput(dentry);
dentry = mounts;
} else
dput(mounts);
mntput(mnt);
}
}
/*
* Note: we compose the file handle now, but as the
* dentry may be negative, it may need to be updated.
*/
err = fh_compose(resfh, exp, dentry, fhp);
if (!err && !dentry->d_inode)
err = nfserr_noent;
out:
return err;
out_nfserr:
err = nfserrno(err);
goto out;
}
/*
* Look up one component of a pathname.
* N.B. After this call _both_ fhp and resfh need an fh_put
*
* If the lookup would cross a mountpoint, and the mounted filesystem
* is exported to the client with NFSEXP_NOHIDE, then the lookup is
* accepted as it stands and the mounted directory is
* returned. Otherwise the covered directory is returned.
* NOTE: this mountpoint crossing is not supported properly by all
* clients and is explicitly disallowed for NFSv3
* NeilBrown <*****@*****.**>
*/
int
nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
int len, struct svc_fh *resfh)
{
struct svc_export *exp;
struct dentry *dparent;
struct dentry *dentry;
int err;
dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
/* Obtain dentry and export. */
err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
if (err)
return err;
dparent = fhp->fh_dentry;
exp = fhp->fh_export;
exp_get(exp);
err = nfserr_acces;
/* Lookup the name, but don't follow links */
if (isdotent(name, len)) {
if (len==1)
dentry = dget(dparent);
else if (dparent != exp->ex_dentry) {
dentry = dget_parent(dparent);
} else if (!EX_NOHIDE(exp))
dentry = dget(dparent); /* .. == . just like at / */
else {
/* checking mountpoint crossing is very different when stepping up */
struct svc_export *exp2 = NULL;
struct dentry *dp;
struct vfsmount *mnt = mntget(exp->ex_mnt);
dentry = dget(dparent);
while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
;
dp = dget_parent(dentry);
dput(dentry);
dentry = dp;
exp2 = exp_parent(exp->ex_client, mnt, dentry,
&rqstp->rq_chandle);
if (IS_ERR(exp2)) {
err = PTR_ERR(exp2);
dput(dentry);
mntput(mnt);
goto out_nfserr;
}
if (!exp2) {
dput(dentry);
dentry = dget(dparent);
} else {
exp_put(exp);
exp = exp2;
}
mntput(mnt);
}
} else {
fh_lock(fhp);
dentry = lookup_one_len(name, dparent, len);
err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_nfserr;
/*
* check if we have crossed a mount point ...
*/
if (d_mountpoint(dentry)) {
if ((err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
dput(dentry);
goto out_nfserr;
}
}
}
/*
* Note: we compose the file handle now, but as the
* dentry may be negative, it may need to be updated.
*/
err = fh_compose(resfh, exp, dentry, fhp);
if (!err && !dentry->d_inode)
err = nfserr_noent;
dput(dentry);
out:
exp_put(exp);
return err;
out_nfserr:
err = nfserrno(err);
goto out;
}
/*
* Unlink a file or directory
* N.B. After this call fhp needs an fh_put
*/
int
nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
char *fname, int flen)
{
struct dentry *dentry, *rdentry;
struct inode *dirp;
int err;
/* N.B. We shouldn't need this test ... handled by dentry layer */
err = nfserr_acces;
if (!flen || isdotent(fname, flen))
goto out;
err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE);
if (err)
goto out;
dentry = fhp->fh_dentry;
dirp = dentry->d_inode;
rdentry = lookup_dentry(fname, dget(dentry), 0);
err = PTR_ERR(rdentry);
if (IS_ERR(rdentry))
goto out_nfserr;
if (!rdentry->d_inode) {
dput(rdentry);
err = nfserr_noent;
goto out;
}
if (type != S_IFDIR) {
/* It's UNLINK */
err = fh_lock_parent(fhp, rdentry);
if (err)
goto out;
err = vfs_unlink(dirp, rdentry);
DQUOT_DROP(dirp);
fh_unlock(fhp);
dput(rdentry);
} else {
/* It's RMDIR */
/* See comments in fs/namei.c:do_rmdir */
rdentry->d_count++;
nfsd_double_down(&dirp->i_sem, &rdentry->d_inode->i_sem);
if (!fhp->fh_pre_mtime)
fhp->fh_pre_mtime = dirp->i_mtime;
fhp->fh_locked = 1;
err = -ENOENT;
if (check_parent(dirp, rdentry))
err = vfs_rmdir(dirp, rdentry);
rdentry->d_count--;
DQUOT_DROP(dirp);
if (!fhp->fh_post_version)
fhp->fh_post_version = dirp->i_version;
fhp->fh_locked = 0;
nfsd_double_up(&dirp->i_sem, &rdentry->d_inode->i_sem);
dput(rdentry);
}
if (err)
goto out_nfserr;
if (EX_ISSYNC(fhp->fh_export))
write_inode_now(dirp);
out:
return err;
out_nfserr:
err = nfserrno(-err);
goto out;
}
