nfsd: take struct file setup fully into nfs4_preprocess_stateid_op

This patch changes nfs4_preprocess_stateid_op so it always returns
a valid struct file if it has been asked for that.  For that we
now allocate a temporary struct file for special stateids, and check
permissions if we got the file structure from the stateid.  This
ensures that all callers will get their handling of special stateids
right, and avoids code duplication.

There is a little wart in here because the read code needs to know
if we allocated a file structure so that it can copy around the
read-ahead parameters.  In the long run we should probably aim to
cache full file structures used with special stateids instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 15 insertions, 24 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 864e2003e8de..5aa7c4e7fc8c 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -760,8 +760,6 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 {
 	__be32 status;
 
-	/* no need to check permission - this will be done in nfsd_read() */
-
 	read->rd_filp = NULL;
 	if (read->rd_offset >= OFFSET_MAX)
 		return nfserr_inval;
@@ -778,9 +776,9 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
 	/* check stateid */
-	if ((status = nfs4_preprocess_stateid_op(SVC_NET(rqstp),
-						 cstate, &read->rd_stateid,
-						 RD_STATE, &read->rd_filp))) {
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &read->rd_stateid,
+			RD_STATE, &read->rd_filp, &read->rd_tmp_file);
+	if (status) {
 		dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
 		goto out;
 	}
@@ -924,8 +922,8 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	int err;
 
 	if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
-		status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
-			&setattr->sa_stateid, WR_STATE, NULL);
+		status = nfs4_preprocess_stateid_op(rqstp, cstate,
+			&setattr->sa_stateid, WR_STATE, NULL, NULL);
 		if (status) {
 			dprintk("NFSD: nfsd4_setattr: couldn't process stateid!\n");
 			return status;
@@ -986,13 +984,11 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	unsigned long cnt;
 	int nvecs;
 
-	/* no need to check permission - this will be done in nfsd_write() */
-
 	if (write->wr_offset >= OFFSET_MAX)
 		return nfserr_inval;
 
-	status = nfs4_preprocess_stateid_op(SVC_NET(rqstp),
-					cstate, stateid, WR_STATE, &filp);
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, stateid, WR_STATE,
+			&filp, NULL);
 	if (status) {
 		dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
 		return status;
@@ -1005,11 +1001,10 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	nvecs = fill_in_write_vector(rqstp->rq_vec, write);
 	WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));
 
-	status =  nfsd_write(rqstp, &cstate->current_fh, filp,
-			     write->wr_offset, rqstp->rq_vec, nvecs,
-			     &cnt, &write->wr_how_written);
-	if (filp)
-		fput(filp);
+	status = nfsd_vfs_write(rqstp, &cstate->current_fh, filp,
+				write->wr_offset, rqstp->rq_vec, nvecs, &cnt,
+				&write->wr_how_written);
+	fput(filp);
 
 	write->wr_bytes_written = cnt;
 
@@ -1023,15 +1018,13 @@ nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	__be32 status = nfserr_notsupp;
 	struct file *file;
 
-	status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
+	status = nfs4_preprocess_stateid_op(rqstp, cstate,
 					    &fallocate->falloc_stateid,
-					    WR_STATE, &file);
+					    WR_STATE, &file, NULL);
 	if (status != nfs_ok) {
 		dprintk("NFSD: nfsd4_fallocate: couldn't process stateid!\n");
 		return status;
 	}
-	if (!file)
-		return nfserr_bad_stateid;
 
 	status = nfsd4_vfs_fallocate(rqstp, &cstate->current_fh, file,
 				     fallocate->falloc_offset,
@@ -1064,15 +1057,13 @@ nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	__be32 status;
 	struct file *file;
 
-	status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
+	status = nfs4_preprocess_stateid_op(rqstp, cstate,
 					    &seek->seek_stateid,
-					    RD_STATE, &file);
+					    RD_STATE, &file, NULL);
 	if (status) {
 		dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n");
 		return status;
 	}
-	if (!file)
-		return nfserr_bad_stateid;
 
 	switch (seek->seek_whence) {
 	case NFS4_CONTENT_DATA: