NFSv4: Save the owner/group name string when doing open

...so that we can do the uid/gid mapping outside the asynchronous RPC
context.
This fixes a bug in the current NFSv4 atomic open code where the client
isn't able to determine what the true uid/gid fields of the file are,
(because the asynchronous nature of the OPEN call denies it the ability
to do an upcall) and so fills them with default values, marking the
inode as needing revalidation.
Unfortunately, in some cases, the VFS will do some additional sanity
checks on the file, and may override the server's decision to allow
the open because it sees the wrong owner/group fields.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 47 insertions, 59 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index dcaf69309d8e..95e92e438407 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2298,7 +2298,7 @@ static void nfs4_xdr_enc_open(struct rpc_rqst *req, struct xdr_stream *xdr,
         encode_getfh(xdr, &hdr);
         encode_getfattr(xdr, args->bitmask, &hdr);
         encode_restorefh(xdr, &hdr);
-        encode_getfattr(xdr, args->bitmask, &hdr);
+        encode_getfattr(xdr, args->dir_bitmask, &hdr);
         encode_nops(&hdr);
 }
 
@@ -3792,7 +3792,8 @@ out_overflow:
 }
 
 static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap,
-                const struct nfs_server *server, uint32_t *uid, int may_sleep)
+                const struct nfs_server *server, uint32_t *uid,
+                struct nfs4_string *owner_name)
 {
         uint32_t len;
         __be32 *p;
@@ -3809,8 +3810,12 @@ static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap,
                 p = xdr_inline_decode(xdr, len);
                 if (unlikely(!p))
                         goto out_overflow;
-                if (!may_sleep) {
-                        /* do nothing */
+                if (owner_name != NULL) {
+                        owner_name->data = kmemdup(p, len, GFP_NOWAIT);
+                        if (owner_name->data != NULL) {
+                                owner_name->len = len;
+                                ret = NFS_ATTR_FATTR_OWNER_NAME;
+                        }
                 } else if (len < XDR_MAX_NETOBJ) {
                         if (nfs_map_name_to_uid(server, (char *)p, len, uid) == 0)
                                 ret = NFS_ATTR_FATTR_OWNER;
@@ -3830,7 +3835,8 @@ out_overflow:
 }
 
 static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap,
-                const struct nfs_server *server, uint32_t *gid, int may_sleep)
+                const struct nfs_server *server, uint32_t *gid,
+                struct nfs4_string *group_name)
 {
         uint32_t len;
         __be32 *p;
@@ -3847,8 +3853,12 @@ static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap,
                 p = xdr_inline_decode(xdr, len);
                 if (unlikely(!p))
                         goto out_overflow;
-                if (!may_sleep) {
-                        /* do nothing */
+                if (group_name != NULL) {
+                        group_name->data = kmemdup(p, len, GFP_NOWAIT);
+                        if (group_name->data != NULL) {
+                                group_name->len = len;
+                                ret = NFS_ATTR_FATTR_GROUP_NAME;
+                        }
                 } else if (len < XDR_MAX_NETOBJ) {
                         if (nfs_map_group_to_gid(server, (char *)p, len, gid) == 0)
                                 ret = NFS_ATTR_FATTR_GROUP;
@@ -4285,7 +4295,7 @@ xdr_error:
 
 static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap,
                 struct nfs_fattr *fattr, struct nfs_fh *fh,
-                const struct nfs_server *server, int may_sleep)
+                const struct nfs_server *server)
 {
         int status;
         umode_t fmode = 0;
@@ -4352,12 +4362,12 @@ static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap,
                 goto xdr_error;
         fattr->valid |= status;
 
-        status = decode_attr_owner(xdr, bitmap, server, &fattr->uid, may_sleep);
+        status = decode_attr_owner(xdr, bitmap, server, &fattr->uid, fattr->owner_name);
         if (status < 0)
                 goto xdr_error;
         fattr->valid |= status;
 
-        status = decode_attr_group(xdr, bitmap, server, &fattr->gid, may_sleep);
+        status = decode_attr_group(xdr, bitmap, server, &fattr->gid, fattr->group_name);
         if (status < 0)
                 goto xdr_error;
         fattr->valid |= status;
@@ -4398,7 +4408,7 @@ xdr_error:
 }
 
 static int decode_getfattr_generic(struct xdr_stream *xdr, struct nfs_fattr *fattr,
-                struct nfs_fh *fh, const struct nfs_server *server, int may_sleep)
+                struct nfs_fh *fh, const struct nfs_server *server)
 {
         __be32 *savep;
         uint32_t attrlen,
@@ -4417,7 +4427,7 @@ static int decode_getfattr_generic(struct xdr_stream *xdr, struct nfs_fattr *fat
         if (status < 0)
                 goto xdr_error;
 
-        status = decode_getfattr_attrs(xdr, bitmap, fattr, fh, server, may_sleep);
+        status = decode_getfattr_attrs(xdr, bitmap, fattr, fh, server);
         if (status < 0)
                 goto xdr_error;
 
@@ -4428,9 +4438,9 @@ xdr_error:
 }
 
 static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
-                const struct nfs_server *server, int may_sleep)
+                const struct nfs_server *server)
 {
-        return decode_getfattr_generic(xdr, fattr, NULL, server, may_sleep);
+        return decode_getfattr_generic(xdr, fattr, NULL, server);
 }
 
 /*
@@ -5711,8 +5721,7 @@ static int nfs4_xdr_dec_open_downgrade(struct rpc_rqst *rqstp,
         status = decode_open_downgrade(xdr, res);
         if (status != 0)
                 goto out;
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -5738,8 +5747,7 @@ static int nfs4_xdr_dec_access(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         status = decode_access(xdr, res);
         if (status != 0)
                 goto out;
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -5768,8 +5776,7 @@ static int nfs4_xdr_dec_lookup(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         status = decode_getfh(xdr, res->fh);
         if (status)
                 goto out;
-        status = decode_getfattr(xdr, res->fattr, res->server
-                        ,!RPC_IS_ASYNC(rqstp->rq_task));
+        status = decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -5795,8 +5802,7 @@ static int nfs4_xdr_dec_lookup_root(struct rpc_rqst *rqstp,
                 goto out;
         status = decode_getfh(xdr, res->fh);
         if (status == 0)
-                status = decode_getfattr(xdr, res->fattr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task));
+                status = decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -5822,8 +5828,7 @@ static int nfs4_xdr_dec_remove(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         status = decode_remove(xdr, &res->cinfo);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->dir_attr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->dir_attr, res->server);
 out:
         return status;
 }
@@ -5856,14 +5861,12 @@ static int nfs4_xdr_dec_rename(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         if (status)
                 goto out;
         /* Current FH is target directory */
-        if (decode_getfattr(xdr, res->new_fattr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task)) != 0)
+        if (decode_getfattr(xdr, res->new_fattr, res->server))
                 goto out;
         status = decode_restorefh(xdr);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->old_fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->old_fattr, res->server);
 out:
         return status;
 }
@@ -5899,14 +5902,12 @@ static int nfs4_xdr_dec_link(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
          * Note order: OP_LINK leaves the directory as the current
          *             filehandle.
          */
-        if (decode_getfattr(xdr, res->dir_attr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task)) != 0)
+        if (decode_getfattr(xdr, res->dir_attr, res->server))
                 goto out;
         status = decode_restorefh(xdr);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -5938,14 +5939,12 @@ static int nfs4_xdr_dec_create(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         status = decode_getfh(xdr, res->fh);
         if (status)
                 goto out;
-        if (decode_getfattr(xdr, res->fattr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task)) != 0)
+        if (decode_getfattr(xdr, res->fattr, res->server))
                 goto out;
         status = decode_restorefh(xdr);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->dir_fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->dir_fattr, res->server);
 out:
         return status;
 }
@@ -5977,8 +5976,7 @@ static int nfs4_xdr_dec_getattr(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         status = decode_putfh(xdr);
         if (status)
                 goto out;
-        status = decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        status = decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -6076,8 +6074,7 @@ static int nfs4_xdr_dec_close(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
          *      an ESTALE error. Shouldn't be a problem,
          *      though, since fattr->valid will remain unset.
          */
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -6108,13 +6105,11 @@ static int nfs4_xdr_dec_open(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
                 goto out;
         if (decode_getfh(xdr, &res->fh) != 0)
                 goto out;
-        if (decode_getfattr(xdr, res->f_attr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task)) != 0)
+        if (decode_getfattr(xdr, res->f_attr, res->server) != 0)
                 goto out;
         if (decode_restorefh(xdr) != 0)
                 goto out;
-        decode_getfattr(xdr, res->dir_attr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->dir_attr, res->server);
 out:
         return status;
 }
@@ -6162,8 +6157,7 @@ static int nfs4_xdr_dec_open_noattr(struct rpc_rqst *rqstp,
         status = decode_open(xdr, res);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->f_attr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->f_attr, res->server);
 out:
         return status;
 }
@@ -6190,8 +6184,7 @@ static int nfs4_xdr_dec_setattr(struct rpc_rqst *rqstp,
         status = decode_setattr(xdr);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -6371,8 +6364,7 @@ static int nfs4_xdr_dec_write(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         if (status)
                 goto out;
         if (res->fattr)
-                decode_getfattr(xdr, res->fattr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task));
+                decode_getfattr(xdr, res->fattr, res->server);
         if (!status)
                 status = res->count;
 out:
@@ -6401,8 +6393,7 @@ static int nfs4_xdr_dec_commit(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
         if (status)
                 goto out;
         if (res->fattr)
-                decode_getfattr(xdr, res->fattr, res->server,
-                                !RPC_IS_ASYNC(rqstp->rq_task));
+                decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -6561,8 +6552,7 @@ static int nfs4_xdr_dec_delegreturn(struct rpc_rqst *rqstp,
         status = decode_delegreturn(xdr);
         if (status != 0)
                 goto out;
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -6591,8 +6581,7 @@ static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req,
                 goto out;
         xdr_enter_page(xdr, PAGE_SIZE);
         status = decode_getfattr(xdr, &res->fs_locations->fattr,
-                                 res->fs_locations->server,
-                                 !RPC_IS_ASYNC(req->rq_task));
+                                 res->fs_locations->server);
 out:
         return status;
 }
@@ -6841,8 +6830,7 @@ static int nfs4_xdr_dec_layoutcommit(struct rpc_rqst *rqstp,
         status = decode_layoutcommit(xdr, rqstp, res);
         if (status)
                 goto out;
-        decode_getfattr(xdr, res->fattr, res->server,
-                        !RPC_IS_ASYNC(rqstp->rq_task));
+        decode_getfattr(xdr, res->fattr, res->server);
 out:
         return status;
 }
@@ -6973,7 +6961,7 @@ int nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
                 goto out_overflow;
 
         if (decode_getfattr_attrs(xdr, bitmap, entry->fattr, entry->fh,
-                                        entry->server, 1) < 0)
+                                        entry->server) < 0)
                 goto out_overflow;
         if (entry->fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
                 entry->ino = entry->fattr->mounted_on_fileid;