[PATCH 3.18 27/47] nfsd: work around a gcc-5.1 warning

From: Greg Kroah-Hartman
Date: Fri Apr 28 2017 - 04:43:19 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd@xxxxxxxx>

commit 6ac75368e1a658903cf57b2bbf66e60d34f55558 upstream.

gcc-5.0 warns about a potential uninitialized variable use in nfsd:

fs/nfsd/nfs4state.c: In function 'nfsd4_process_open2':
fs/nfsd/nfs4state.c:3781:3: warning: 'old_deny_bmap' may be used uninitialized in this function [-Wmaybe-uninitialized]
reset_union_bmap_deny(old_deny_bmap, stp);
^
fs/nfsd/nfs4state.c:3760:16: note: 'old_deny_bmap' was declared here
unsigned char old_deny_bmap;
^

This is a false positive, the code path that is warned about cannot
actually be reached.

This adds an initialization for the variable to make the warning go
away.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/nfsd/nfs4state.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3757,7 +3757,7 @@ 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)
{
__be32 status;
- unsigned char old_deny_bmap;
+ unsigned char old_deny_bmap = stp->st_deny_bmap;

if (!test_access(open->op_share_access, stp))
return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open);
@@ -3766,7 +3766,6 @@ nfs4_upgrade_open(struct svc_rqst *rqstp
spin_lock(&fp->fi_lock);
status = nfs4_file_check_deny(fp, open->op_share_deny);
if (status == nfs_ok) {
- old_deny_bmap = stp->st_deny_bmap;
set_deny(open->op_share_deny, stp);
fp->fi_share_deny |=
(open->op_share_deny & NFS4_SHARE_DENY_BOTH);