From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
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@xxxxxxxxxx>
---
fs/nfsd/export.c | 4 +-
fs/nfsd/nfs4xdr.c | 106 ++++++++++++++++++++++++++++++++-----------
include/linux/nfsd/export.h | 1
3 files changed, 81 insertions(+), 30 deletions(-)
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index f4cc1e2..d9a6611 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1010,7 +1010,7 @@ rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
return exp;
}
-static struct svc_export *find_fsidzero_export(struct svc_rqst *rqstp)
+struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
{
u32 fsidv[2];
@@ -1030,7 +1030,7 @@ exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
struct svc_export *exp;
__be32 rv;
- exp = find_fsidzero_export(rqstp);
+ exp = rqst_find_fsidzero_export(rqstp);
if (IS_ERR(exp))
return nfserrno(PTR_ERR(exp));
rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index c8bf405..f7b068e 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1697,36 +1697,89 @@ 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_resource;
- 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;
+ 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);
+ }
- 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;
+ *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--;
}
- path += rootlen;
-out:
- fh_put(&tmp_fh);
- return path;
+
+ *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;
}
/*
@@ -1740,11 +1793,8 @@ 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)
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index 8a31a20..7ba3fd4 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -137,6 +137,7 @@ struct svc_export * rqst_exp_get_by_name(struct svc_rqst *,
struct path *);
struct svc_export * rqst_exp_parent(struct svc_rqst *,
struct path *);
+struct svc_export * rqst_find_fsidzero_export(struct svc_rqst *);
int exp_rootfh(struct auth_domain *,
char *path, struct knfsd_fh *, int maxsize);
__be32 exp_pseudoroot(struct svc_rqst *, struct svc_fh *);
--
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