knfsd: nfsd4: make readonly access depend on pseudoflavor

Allow readonly access to vary depending on the pseudoflavor, using the flag
passed with each pseudoflavor in the export downcall.  The rest of the flags
are ignored for now, though some day we might also allow id squashing to vary
based on the flavor.

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 24 insertions, 10 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index d5fe392b14fb..8d2b49914843 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -255,7 +255,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
                 goto out;
 
         /* Finally, check access permissions. */
-        error = nfsd_permission(exp, dentry, access);
+        error = nfsd_permission(rqstp, exp, dentry, access);
 
         if (error) {
                 dprintk("fh_verify: %s/%s permission failure, "
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index b2c7147aa921..977a71f64e19 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -278,7 +278,8 @@ nfsd_proc_create(struct svc_rqst *rqstp, struct nfsd_createargs *argp,
                                          *   echo thing > device-special-file-or-pipe
                                          * by doing a CREATE with type==0
                                          */
-                                        nfserr = nfsd_permission(newfhp->fh_export,
+                                        nfserr = nfsd_permission(rqstp,
+                                                                 newfhp->fh_export,
                                                                  newfhp->fh_dentry,
                                                                  MAY_WRITE|MAY_LOCAL_ACCESS);
                                         if (nfserr && nfserr != nfserr_rofs)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 8e109e586a74..e90f4a8a1d01 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -328,7 +328,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
         /* The size case is special. It changes the file as well as the attributes.  */
         if (iap->ia_valid & ATTR_SIZE) {
                 if (iap->ia_size < inode->i_size) {
-                        err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
+                        err = nfsd_permission(rqstp, fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
                         if (err)
                                 goto out;
                 }
@@ -616,7 +616,7 @@ nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *suppor
 
                         sresult |= map->access;
 
-                        err2 = nfsd_permission(export, dentry, map->how);
+                        err2 = nfsd_permission(rqstp, export, dentry, map->how);
                         switch (err2) {
                         case nfs_ok:
                                 result |= map->access;
@@ -1043,7 +1043,7 @@ nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
         __be32          err;
 
         if (file) {
-                err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
+                err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
                                 MAY_READ|MAY_OWNER_OVERRIDE);
                 if (err)
                         goto out;
@@ -1072,7 +1072,7 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
         __be32                  err = 0;
 
         if (file) {
-                err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
+                err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
                                 MAY_WRITE|MAY_OWNER_OVERRIDE);
                 if (err)
                         goto out;
@@ -1801,7 +1801,8 @@ nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat)
  * Check for a user's access permissions to this inode.
  */
 __be32
-nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc)
+nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
+                                        struct dentry *dentry, int acc)
 {
         struct inode    *inode = dentry->d_inode;
         int             err;
@@ -1832,7 +1833,7 @@ nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc)
          */
         if (!(acc & MAY_LOCAL_ACCESS))
                 if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
-                        if (EX_RDONLY(exp) || IS_RDONLY(inode))
+                        if (EX_RDONLY(exp, rqstp) || IS_RDONLY(inode))
                                 return nfserr_rofs;
                         if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
                                 return nfserr_perm;
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index 424be41130ba..a01f775cb944 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -112,10 +112,21 @@ struct svc_expkey {
 
 #define EX_SECURE(exp)          (!((exp)->ex_flags & NFSEXP_INSECURE_PORT))
 #define EX_ISSYNC(exp)          (!((exp)->ex_flags & NFSEXP_ASYNC))
-#define EX_RDONLY(exp)          ((exp)->ex_flags & NFSEXP_READONLY)
 #define EX_NOHIDE(exp)          ((exp)->ex_flags & NFSEXP_NOHIDE)
 #define EX_WGATHER(exp)         ((exp)->ex_flags & NFSEXP_GATHERED_WRITES)
 
+static inline int EX_RDONLY(struct svc_export *exp, struct svc_rqst *rqstp)
+{
+        struct exp_flavor_info *f;
+        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+
+        for (f = exp->ex_flavors; f < end; f++) {
+                if (f->pseudoflavor == rqstp->rq_flavor)
+                        return f->flags & NFSEXP_READONLY;
+        }
+        return exp->ex_flags & NFSEXP_READONLY;
+}
+
 __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp);
 
 /*
diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
index 62499c2f0918..54ef1a18a56c 100644
--- a/include/linux/nfsd/nfsd.h
+++ b/include/linux/nfsd/nfsd.h
@@ -119,7 +119,8 @@ __be32		nfsd_statfs(struct svc_rqst *, struct svc_fh *,
                                 struct kstatfs *);
 
 int             nfsd_notify_change(struct inode *, struct iattr *);
-__be32          nfsd_permission(struct svc_export *, struct dentry *, int);
+__be32          nfsd_permission(struct svc_rqst *, struct svc_export *,
+                                struct dentry *, int);
 int             nfsd_sync_dir(struct dentry *dp);
 
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)