Commit 7e54636e authored by Neil Brown's avatar Neil Brown Committed by Linus Torvalds

[PATCH] kNFSd: Allow nfsv4 readdir to return filehandle when a mountpoint is found is a directory

From: "William A.(Andy) Adamson" <andros@citi.umich.edu>

When readdir is enumerating a directory and finds a mountpoint,
it needs to do a bit of extra work to find the filehandle to be
returned in the readdir reply.

It is even possible that finding the filehandle requires an up-call,
so the request might be dropped to be re-tried later.
parent 69408a2f
...@@ -1425,6 +1425,7 @@ nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen, ...@@ -1425,6 +1425,7 @@ nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen,
u32 *p = cd->buffer; u32 *p = cd->buffer;
u32 *attrlenp; u32 *attrlenp;
struct dentry *dentry; struct dentry *dentry;
struct svc_export *exp = cd->rd_fhp->fh_export;
u32 bmval0, bmval1; u32 bmval0, bmval1;
int nfserr = 0; int nfserr = 0;
...@@ -1454,9 +1455,7 @@ nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen, ...@@ -1454,9 +1455,7 @@ nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen,
if ((bmval0 & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_FILEID)) || bmval1) { if ((bmval0 & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_FILEID)) || bmval1) {
/* /*
* "Heavyweight" case: we have no choice except to * "Heavyweight" case: we have no choice except to
* call nfsd4_encode_fattr(). As far as I know, * call nfsd4_encode_fattr().
* only Windows clients will trigger this code
* path.
*/ */
dentry = lookup_one_len(name, cd->rd_fhp->fh_dentry, namlen); dentry = lookup_one_len(name, cd->rd_fhp->fh_dentry, namlen);
if (IS_ERR(dentry)) { if (IS_ERR(dentry)) {
...@@ -1464,10 +1463,25 @@ nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen, ...@@ -1464,10 +1463,25 @@ nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen,
goto error; goto error;
} }
nfserr = nfsd4_encode_fattr(NULL, cd->rd_fhp->fh_export, if (d_mountpoint(dentry)) {
dentry, p, &buflen, cd->rd_bmval); if ((nfserr = nfsd_cross_mnt(cd->rd_rqstp, &dentry,
&exp))) {
/*
* -EAGAIN is the only error returned from
* nfsd_cross_mnt() and it indicates that an
* up-call has been initiated to fill in the export
* options on exp. When the answer comes back,
* this call will be retried.
*/
dput(dentry); dput(dentry);
nfserr = nfserr_dropit;
goto error;
}
}
nfserr = nfsd4_encode_fattr(NULL, exp,
dentry, p, &buflen, cd->rd_bmval);
if (!nfserr) { if (!nfserr) {
p += buflen; p += buflen;
goto out; goto out;
......
...@@ -74,6 +74,46 @@ struct raparms { ...@@ -74,6 +74,46 @@ struct raparms {
static struct raparms * raparml; static struct raparms * raparml;
static struct raparms * raparm_cache; static struct raparms * raparm_cache;
/*
* Called from nfsd_lookup and encode_dirent. Check if we have crossed
* a mount point.
* Returns -EAGAIN leaving *dpp and *expp unchanged,
* or nfs_ok having possibly changed *dpp and *expp
*/
int
nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
struct svc_export **expp)
{
struct svc_export *exp = *expp, *exp2 = NULL;
struct dentry *dentry = *dpp;
struct vfsmount *mnt = mntget(exp->ex_mnt);
struct dentry *mounts = dget(dentry);
int err = nfs_ok;
while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));
exp2 = exp_get_by_name(exp->ex_client, mnt, mounts, &rqstp->rq_chandle);
if (IS_ERR(exp2)) {
err = PTR_ERR(exp2);
dput(mounts);
mntput(mnt);
goto out;
}
if (exp2 && ((exp->ex_flags & NFSEXP_CROSSMNT) || EX_NOHIDE(exp2))) {
/* successfully crossed mount point */
exp_put(exp);
*expp = exp2;
dput(dentry);
*dpp = mounts;
} else {
if (exp2) exp_put(exp2);
dput(mounts);
}
mntput(mnt);
out:
return err;
}
/* /*
* Look up one component of a pathname. * Look up one component of a pathname.
* N.B. After this call _both_ fhp and resfh need an fh_put * N.B. After this call _both_ fhp and resfh need an fh_put
...@@ -154,34 +194,10 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, ...@@ -154,34 +194,10 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
* check if we have crossed a mount point ... * check if we have crossed a mount point ...
*/ */
if (d_mountpoint(dentry)) { if (d_mountpoint(dentry)) {
struct svc_export *exp2 = NULL; if ((err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
struct vfsmount *mnt = mntget(exp->ex_mnt);
struct dentry *mounts = dget(dentry);
while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts))
;
exp2 = exp_get_by_name(exp->ex_client, mnt,
mounts, &rqstp->rq_chandle);
if (IS_ERR(exp2)) {
err = PTR_ERR(exp2);
dput(mounts);
dput(dentry); dput(dentry);
mntput(mnt);
goto out_nfserr; goto out_nfserr;
} }
if (exp2 &&
((exp->ex_flags & NFSEXP_CROSSMNT)
|| EX_NOHIDE(exp2))) {
/* successfully crossed mount point */
exp_put(exp);
exp = exp2;
dput(dentry);
dentry = mounts;
} else {
if (exp2) exp_put(exp2);
dput(mounts);
}
mntput(mnt);
} }
} }
/* /*
......
...@@ -69,6 +69,8 @@ int nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp); ...@@ -69,6 +69,8 @@ int nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp);
int fh_lock_parent(struct svc_fh *, struct dentry *); int fh_lock_parent(struct svc_fh *, struct dentry *);
int nfsd_racache_init(int); int nfsd_racache_init(int);
void nfsd_racache_shutdown(void); void nfsd_racache_shutdown(void);
int nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
struct svc_export **expp);
int nfsd_lookup(struct svc_rqst *, struct svc_fh *, int nfsd_lookup(struct svc_rqst *, struct svc_fh *,
const char *, int, struct svc_fh *); const char *, int, struct svc_fh *);
int nfsd_setattr(struct svc_rqst *, struct svc_fh *, int nfsd_setattr(struct svc_rqst *, struct svc_fh *,
......
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