nfsd: fix file access refcount leak when nfsd4_truncate fails

nfsd4_process_open2 will currently will get access to the file, and then
call nfsd4_truncate to (possibly) truncate it. If that operation fails
though, then the access references will never be released as the
nfs4_ol_stateid is never initialized.

Fix by moving the nfsd4_truncate call into nfs4_get_vfs_file, ensuring
that the refcounts are properly put if the truncate fails.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8242385..c473bd6 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3046,6 +3046,21 @@ static inline int nfs4_access_to_access(u32 nfs4_access)
        return flags;
 }
 
+static inline __be32
+nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
+               struct nfsd4_open *open)
+{
+       struct iattr iattr = {
+               .ia_valid = ATTR_SIZE,
+               .ia_size = 0,
+       };
+       if (!open->op_truncate)
+               return 0;
+       if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
+               return nfserr_inval;
+       return nfsd_setattr(rqstp, fh, &iattr, 0, (time_t)0);
+}
+
 static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
                struct svc_fh *cur_fh, struct nfsd4_open *open)
 {
@@ -3057,53 +3072,39 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
                status = nfsd_open(rqstp, cur_fh, S_IFREG, access,
                        &fp->fi_fds[oflag]);
                if (status)
-                       return status;
+                       goto out;
        }
        nfs4_file_get_access(fp, oflag);
 
+       status = nfsd4_truncate(rqstp, cur_fh, open);
+       if (status)
+               goto out_put_access;
+
        return nfs_ok;
-}
 
-static inline __be32
-nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
-               struct nfsd4_open *open)
-{
-       struct iattr iattr = {
-               .ia_valid = ATTR_SIZE,
-               .ia_size = 0,
-       };
-       if (!open->op_truncate)
-               return 0;
-       if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
-               return nfserr_inval;
-       return nfsd_setattr(rqstp, fh, &iattr, 0, (time_t)0);
+out_put_access:
+       nfs4_file_put_access(fp, oflag);
+out:
+       return status;
 }
 
 static __be32
 nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open)
 {
        u32 op_share_access = open->op_share_access;
-       bool new_access;
        __be32 status;
 
-       new_access = !test_access(op_share_access, stp);
-       if (new_access) {
+       if (!test_access(op_share_access, stp))
                status = nfs4_get_vfs_file(rqstp, fp, cur_fh, open);
-               if (status)
-                       return status;
-       }
-       status = nfsd4_truncate(rqstp, cur_fh, open);
-       if (status) {
-               if (new_access) {
-                       int oflag = nfs4_access_to_omode(op_share_access);
-                       nfs4_file_put_access(fp, oflag);
-               }
+       else
+               status = nfsd4_truncate(rqstp, cur_fh, open);
+
+       if (status)
                return status;
-       }
+
        /* remember the open */
        set_access(op_share_access, stp);
        set_deny(open->op_share_deny, stp);
-
        return nfs_ok;
 }
 
@@ -3354,9 +3355,6 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
                status = nfs4_get_vfs_file(rqstp, fp, current_fh, open);
                if (status)
                        goto out;
-               status = nfsd4_truncate(rqstp, current_fh, open);
-               if (status)
-                       goto out;
                stp = open->op_stp;
                open->op_stp = NULL;
                init_open_stateid(stp, fp, open);