| Message ID | 20240823181423.20458-6-snitzer@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | nfs/nfsd: add support for localio | expand |
On Fri, Aug 23, 2024 at 02:14:03PM -0400, Mike Snitzer wrote: > From: NeilBrown <neilb@suse.de> > > nfsd_file_acquire_local() can be used to look up a file by filehandle > without having a struct svc_rqst. This can be used by NFS LOCALIO to > allow the NFS client to bypass the NFS protocol to directly access a > file provided by the NFS server which is running in the same kernel. > > In nfsd_file_do_acquire() care is taken to always use fh_verify() if > rqstp is not NULL (as is the case for non-LOCALIO callers). Otherwise > the non-LOCALIO callers will not supply the correct and required > arguments to __fh_verify (e.g. nfs_vers is 0, gssclient isn't passed). > > Also, use GC for nfsd_file returned by nfsd_file_acquire_local. GC > offers performance improvements if/when a file is reopened before > launderette cleans it from the filecache's LRU. > > Suggested-by: Jeff Layton <jlayton@kernel.org> # use filecache's GC > Signed-off-by: NeilBrown <neilb@suse.de> > Co-developed-by: Mike Snitzer <snitzer@kernel.org> > Signed-off-by: Mike Snitzer <snitzer@kernel.org> > --- > fs/nfsd/filecache.c | 63 ++++++++++++++++++++++++++++++++++++++++----- > fs/nfsd/filecache.h | 4 +++ > fs/nfsd/nfsfh.c | 2 +- > fs/nfsd/nfsfh.h | 5 ++++ > 4 files changed, 66 insertions(+), 8 deletions(-) > > diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c > index 9e9d246f993c..94ecb9ed0ed1 100644 > --- a/fs/nfsd/filecache.c > +++ b/fs/nfsd/filecache.c > @@ -982,12 +982,14 @@ nfsd_file_is_cached(struct inode *inode) > } > > static __be32 > -nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, > +nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net, > + struct svc_cred *cred, int nfs_vers, > + struct auth_domain *client, > + struct svc_fh *fhp, > unsigned int may_flags, struct file *file, > struct nfsd_file **pnf, bool want_gc) > { > unsigned char need = may_flags & NFSD_FILE_MAY_MASK; > - struct net *net = SVC_NET(rqstp); > struct nfsd_file *new, *nf; > bool stale_retry = true; > bool open_retry = true; > @@ -996,8 +998,13 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, > int ret; > > retry: > - status = fh_verify(rqstp, fhp, S_IFREG, > - may_flags|NFSD_MAY_OWNER_OVERRIDE); > + if (rqstp) { > + status = fh_verify(rqstp, fhp, S_IFREG, > + may_flags|NFSD_MAY_OWNER_OVERRIDE); > + } else { > + status = __fh_verify(NULL, net, cred, nfs_vers, client, NULL, fhp, > + S_IFREG, may_flags|NFSD_MAY_OWNER_OVERRIDE); > + } > if (status != nfs_ok) > return status; > inode = d_inode(fhp->fh_dentry); > @@ -1143,7 +1150,8 @@ __be32 > nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp, > unsigned int may_flags, struct nfsd_file **pnf) > { > - return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, true); > + return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, 0, NULL, > + fhp, may_flags, NULL, pnf, true); > } > > /** > @@ -1167,7 +1175,47 @@ __be32 > nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, > unsigned int may_flags, struct nfsd_file **pnf) > { > - return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, false); > + return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, 0, NULL, > + fhp, may_flags, NULL, pnf, false); > +} > + > +/** > + * nfsd_file_acquire_local - Get a struct nfsd_file with an open file for localio > + * @net: The network namespace in which to perform a lookup > + * @cred: the user credential with which to validate access > + * @nfs_vers: NFS version number to assume for request > + * @client: the auth_domain for LOCALIO lookup > + * @fhp: the NFS filehandle of the file to be opened > + * @may_flags: NFSD_MAY_ settings for the file > + * @pnf: OUT: new or found "struct nfsd_file" object > + * > + * This file lookup interface provide access to a file given the > + * filehandle and credential. No connection-based authorisation > + * is performed and in that way it is quite different to other > + * file access mediated by nfsd. It allows a kernel module such as the NFS > + * client to reach across network and filesystem namespaces to access > + * a file. The security implications of this should be carefully > + * considered before use. > + * > + * The nfsd_file object returned by this API is reference-counted > + * and garbage-collected. The object is retained for a few > + * seconds after the final nfsd_file_put() in case the caller > + * wants to re-use it. > + * > + * Return values: > + * %nfs_ok - @pnf points to an nfsd_file with its reference > + * count boosted. > + * > + * On error, an nfsstat value in network byte order is returned. > + */ > +__be32 > +nfsd_file_acquire_local(struct net *net, struct svc_cred *cred, > + int nfs_vers, struct auth_domain *client, > + struct svc_fh *fhp, > + unsigned int may_flags, struct nfsd_file **pnf) > +{ > + return nfsd_file_do_acquire(NULL, net, cred, nfs_vers, client, > + fhp, may_flags, NULL, pnf, true); > } > > /** > @@ -1193,7 +1241,8 @@ nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp, > unsigned int may_flags, struct file *file, > struct nfsd_file **pnf) > { > - return nfsd_file_do_acquire(rqstp, fhp, may_flags, file, pnf, false); > + return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, 0, NULL, > + fhp, may_flags, file, pnf, false); > } > > /* > diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h > index 3fbec24eea6c..6dab41f8541e 100644 > --- a/fs/nfsd/filecache.h > +++ b/fs/nfsd/filecache.h > @@ -66,5 +66,9 @@ __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, > __be32 nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp, > unsigned int may_flags, struct file *file, > struct nfsd_file **nfp); > +__be32 nfsd_file_acquire_local(struct net *net, struct svc_cred *cred, > + int nfs_vers, struct auth_domain *client, > + struct svc_fh *fhp, > + unsigned int may_flags, struct nfsd_file **pnf); > int nfsd_file_cache_stats_show(struct seq_file *m, void *v); > #endif /* _FS_NFSD_FILECACHE_H */ > diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c > index 19e173187ab9..3635c0390cab 100644 > --- a/fs/nfsd/nfsfh.c > +++ b/fs/nfsd/nfsfh.c > @@ -300,7 +300,7 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct net *net, > return error; > } > __fh_verify() becomes a public API here, so it now needs the kdoc comment (removed in 4/N) restored. Consider not removing that comment in 4/N. > -static __be32 > +__be32 > __fh_verify(struct svc_rqst *rqstp, > struct net *net, struct svc_cred *cred, > int nfs_vers, struct auth_domain *client, > diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h > index 8d46e203d139..1429bee0ac1c 100644 > --- a/fs/nfsd/nfsfh.h > +++ b/fs/nfsd/nfsfh.h > @@ -217,6 +217,11 @@ extern char * SVCFH_fmt(struct svc_fh *fhp); > * Function prototypes > */ > __be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int); > +__be32 __fh_verify(struct svc_rqst *rqstp, > + struct net *net, struct svc_cred *cred, > + int nfs_vers, struct auth_domain *client, > + struct auth_domain *gssclient, > + struct svc_fh *fhp, umode_t type, int access); > __be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *); > __be32 fh_update(struct svc_fh *); > void fh_put(struct svc_fh *); > -- > 2.44.0 > >
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 9e9d246f993c..94ecb9ed0ed1 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -982,12 +982,14 @@ nfsd_file_is_cached(struct inode *inode) } static __be32 -nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, +nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net, + struct svc_cred *cred, int nfs_vers, + struct auth_domain *client, + struct svc_fh *fhp, unsigned int may_flags, struct file *file, struct nfsd_file **pnf, bool want_gc) { unsigned char need = may_flags & NFSD_FILE_MAY_MASK; - struct net *net = SVC_NET(rqstp); struct nfsd_file *new, *nf; bool stale_retry = true; bool open_retry = true; @@ -996,8 +998,13 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, int ret; retry: - status = fh_verify(rqstp, fhp, S_IFREG, - may_flags|NFSD_MAY_OWNER_OVERRIDE); + if (rqstp) { + status = fh_verify(rqstp, fhp, S_IFREG, + may_flags|NFSD_MAY_OWNER_OVERRIDE); + } else { + status = __fh_verify(NULL, net, cred, nfs_vers, client, NULL, fhp, + S_IFREG, may_flags|NFSD_MAY_OWNER_OVERRIDE); + } if (status != nfs_ok) return status; inode = d_inode(fhp->fh_dentry); @@ -1143,7 +1150,8 @@ __be32 nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp, unsigned int may_flags, struct nfsd_file **pnf) { - return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, true); + return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, 0, NULL, + fhp, may_flags, NULL, pnf, true); } /** @@ -1167,7 +1175,47 @@ __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, unsigned int may_flags, struct nfsd_file **pnf) { - return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, false); + return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, 0, NULL, + fhp, may_flags, NULL, pnf, false); +} + +/** + * nfsd_file_acquire_local - Get a struct nfsd_file with an open file for localio + * @net: The network namespace in which to perform a lookup + * @cred: the user credential with which to validate access + * @nfs_vers: NFS version number to assume for request + * @client: the auth_domain for LOCALIO lookup + * @fhp: the NFS filehandle of the file to be opened + * @may_flags: NFSD_MAY_ settings for the file + * @pnf: OUT: new or found "struct nfsd_file" object + * + * This file lookup interface provide access to a file given the + * filehandle and credential. No connection-based authorisation + * is performed and in that way it is quite different to other + * file access mediated by nfsd. It allows a kernel module such as the NFS + * client to reach across network and filesystem namespaces to access + * a file. The security implications of this should be carefully + * considered before use. + * + * The nfsd_file object returned by this API is reference-counted + * and garbage-collected. The object is retained for a few + * seconds after the final nfsd_file_put() in case the caller + * wants to re-use it. + * + * Return values: + * %nfs_ok - @pnf points to an nfsd_file with its reference + * count boosted. + * + * On error, an nfsstat value in network byte order is returned. + */ +__be32 +nfsd_file_acquire_local(struct net *net, struct svc_cred *cred, + int nfs_vers, struct auth_domain *client, + struct svc_fh *fhp, + unsigned int may_flags, struct nfsd_file **pnf) +{ + return nfsd_file_do_acquire(NULL, net, cred, nfs_vers, client, + fhp, may_flags, NULL, pnf, true); } /** @@ -1193,7 +1241,8 @@ nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp, unsigned int may_flags, struct file *file, struct nfsd_file **pnf) { - return nfsd_file_do_acquire(rqstp, fhp, may_flags, file, pnf, false); + return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, 0, NULL, + fhp, may_flags, file, pnf, false); } /* diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index 3fbec24eea6c..6dab41f8541e 100644 --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -66,5 +66,9 @@ __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, __be32 nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp, unsigned int may_flags, struct file *file, struct nfsd_file **nfp); +__be32 nfsd_file_acquire_local(struct net *net, struct svc_cred *cred, + int nfs_vers, struct auth_domain *client, + struct svc_fh *fhp, + unsigned int may_flags, struct nfsd_file **pnf); int nfsd_file_cache_stats_show(struct seq_file *m, void *v); #endif /* _FS_NFSD_FILECACHE_H */ diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index 19e173187ab9..3635c0390cab 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -300,7 +300,7 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct net *net, return error; } -static __be32 +__be32 __fh_verify(struct svc_rqst *rqstp, struct net *net, struct svc_cred *cred, int nfs_vers, struct auth_domain *client, diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h index 8d46e203d139..1429bee0ac1c 100644 --- a/fs/nfsd/nfsfh.h +++ b/fs/nfsd/nfsfh.h @@ -217,6 +217,11 @@ extern char * SVCFH_fmt(struct svc_fh *fhp); * Function prototypes */ __be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int); +__be32 __fh_verify(struct svc_rqst *rqstp, + struct net *net, struct svc_cred *cred, + int nfs_vers, struct auth_domain *client, + struct auth_domain *gssclient, + struct svc_fh *fhp, umode_t type, int access); __be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *); __be32 fh_update(struct svc_fh *); void fh_put(struct svc_fh *);