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NFSD: Cleanup for nfsd4_path()

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The current code is sort of hackish in that it assumes a referral is always
matched to an export. When we add support for junctions that may not be the
case.
We can replace nfsd4_path() with a function that encodes the components
directly from the dentries. Since nfsd4_path is currently the only user of
the 'ex_pathname' field in struct svc_export, this has the added benefit
of allowing us to get rid of that.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Trond Myklebust
2011-09-12 19:37:06 -04:00
committed by J. Bruce Fields
parent ee626a77d3
commit ed748aacb8
3 changed files with 82 additions and 31 deletions
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108
fs/nfsd/nfs4xdr.c
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@@ -1696,36 +1696,89 @@ static __be32 nfsd4_encode_fs_location4(struct nfsd4_fs_location *location,
}
/*
* Return the path to an export point in the pseudo filesystem namespace
* Returned string is safe to use as long as the caller holds a reference
* to @exp.
* Encode a path in RFC3530 'pathname4' format
*/
static char *nfsd4_path(struct svc_rqst *rqstp, struct svc_export *exp, __be32 *stat)
static __be32 nfsd4_encode_path(const struct path *root,
const struct path *path, __be32 **pp, int *buflen)
{
struct svc_fh tmp_fh;
char *path = NULL, *rootpath;
size_t rootlen;
struct path cur = {
.mnt = path->mnt,
.dentry = path->dentry,
};
__be32 *p = *pp;
struct dentry **components = NULL;
unsigned int ncomponents = 0;
__be32 err = nfserr_jukebox;
fh_init(&tmp_fh, NFS4_FHSIZE);
*stat = exp_pseudoroot(rqstp, &tmp_fh);
if (*stat)
return NULL;
rootpath = tmp_fh.fh_export->ex_pathname;
dprintk("nfsd4_encode_components(");
path = exp->ex_pathname;
rootlen = strlen(rootpath);
if (strncmp(path, rootpath, rootlen)) {
dprintk("nfsd: fs_locations failed;"
"%s is not contained in %s\n", path, rootpath);
*stat = nfserr_notsupp;
path = NULL;
goto out;
path_get(&cur);
/* First walk the path up to the nfsd root, and store the
* dentries/path components in an array.
*/
for (;;) {
if (cur.dentry == root->dentry && cur.mnt == root->mnt)
break;
if (cur.dentry == cur.mnt->mnt_root) {
if (follow_up(&cur))
continue;
goto out_free;
}
if ((ncomponents & 15) == 0) {
struct dentry **new;
new = krealloc(components,
sizeof(*new) * (ncomponents + 16),
GFP_KERNEL);
if (!new)
goto out_free;
components = new;
}
components[ncomponents++] = cur.dentry;
cur.dentry = dget_parent(cur.dentry);
}
path += rootlen;
out:
fh_put(&tmp_fh);
return path;
*buflen -= 4;
if (*buflen < 0)
goto out_free;
WRITE32(ncomponents);
while (ncomponents) {
struct dentry *dentry = components[ncomponents - 1];
unsigned int len = dentry->d_name.len;
*buflen -= 4 + (XDR_QUADLEN(len) << 2);
if (*buflen < 0)
goto out_free;
WRITE32(len);
WRITEMEM(dentry->d_name.name, len);
dprintk("/%s", dentry->d_name.name);
dput(dentry);
ncomponents--;
}
*pp = p;
err = 0;
out_free:
dprintk(")\n");
while (ncomponents)
dput(components[--ncomponents]);
kfree(components);
path_put(&cur);
return err;
}
static __be32 nfsd4_encode_fsloc_fsroot(struct svc_rqst *rqstp,
const struct path *path, __be32 **pp, int *buflen)
{
struct svc_export *exp_ps;
__be32 res;
exp_ps = rqst_find_fsidzero_export(rqstp);
if (IS_ERR(exp_ps))
return nfserrno(PTR_ERR(exp_ps));
res = nfsd4_encode_path(&exp_ps->ex_path, path, pp, buflen);
exp_put(exp_ps);
return res;
}
/*
@@ -1739,11 +1792,8 @@ static __be32 nfsd4_encode_fs_locations(struct svc_rqst *rqstp,
int i;
__be32 *p = *pp;
struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
char *root = nfsd4_path(rqstp, exp, &status);
if (status)
return status;
status = nfsd4_encode_components('/', root, &p, buflen);
status = nfsd4_encode_fsloc_fsroot(rqstp, &exp->ex_path, &p, buflen);
if (status)
return status;
if ((*buflen -= 4) < 0)