fs/nfs/nfs42xdr.c:1131 decode_read_plus() warn: missing error code? 'status'

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   44c026a73be8038f03dbdeef028b642880cf1511
commit: d3b00a802c845a6021148ce2e669b5a0b5729959 NFS: Replace the READ_PLUS decoding code
config: microblaze-randconfig-m041-20230522 (https://download.01.org/0day-ci/archive/20230522/202305222209.6l5VM2lL-lkp@xxxxxxxxx/config)
compiler: microblaze-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
| Closes: https://lore.kernel.org/r/202305222209.6l5VM2lL-lkp@xxxxxxxxx/

New smatch warnings:
fs/nfs/nfs42xdr.c:1131 decode_read_plus() warn: missing error code? 'status'

Old smatch warnings:
fs/nfs/nfs4xdr.c:1194 encode_attrs() error: we previously assumed 'umask' could be null (see line 1103)

vim +/status +1131 fs/nfs/nfs42xdr.c

c567552612ece7 Anna Schumaker  2014-05-28  1108  static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
c567552612ece7 Anna Schumaker  2014-05-28  1109  {
82f98c8b116bd7 Trond Myklebust 2020-12-08  1110  	struct nfs_pgio_header *hdr =
82f98c8b116bd7 Trond Myklebust 2020-12-08  1111  		container_of(res, struct nfs_pgio_header, res);
82f98c8b116bd7 Trond Myklebust 2020-12-08  1112  	struct nfs_pgio_args *args = &hdr->args;
d3b00a802c845a Anna Schumaker  2022-07-21  1113  	uint32_t segments;
d3b00a802c845a Anna Schumaker  2022-07-21  1114  	struct read_plus_segment *segs;
bff049a3b5001e Anna Schumaker  2020-04-01  1115  	int status, i;
d3b00a802c845a Anna Schumaker  2022-07-21  1116  	char scratch_buf[16];
c567552612ece7 Anna Schumaker  2014-05-28  1117  	__be32 *p;
c567552612ece7 Anna Schumaker  2014-05-28  1118  
c567552612ece7 Anna Schumaker  2014-05-28  1119  	status = decode_op_hdr(xdr, OP_READ_PLUS);
c567552612ece7 Anna Schumaker  2014-05-28  1120  	if (status)
c567552612ece7 Anna Schumaker  2014-05-28  1121  		return status;
c567552612ece7 Anna Schumaker  2014-05-28  1122  
c567552612ece7 Anna Schumaker  2014-05-28  1123  	p = xdr_inline_decode(xdr, 4 + 4);
c567552612ece7 Anna Schumaker  2014-05-28  1124  	if (unlikely(!p))
c567552612ece7 Anna Schumaker  2014-05-28  1125  		return -EIO;
c567552612ece7 Anna Schumaker  2014-05-28  1126  
1ee6310119a5b4 Trond Myklebust 2020-12-08  1127  	res->count = 0;
d3b00a802c845a Anna Schumaker  2022-07-21  1128  	res->eof = be32_to_cpup(p++);
c567552612ece7 Anna Schumaker  2014-05-28  1129  	segments = be32_to_cpup(p++);
c567552612ece7 Anna Schumaker  2014-05-28  1130  	if (segments == 0)
d3b00a802c845a Anna Schumaker  2022-07-21 @1131  		return status;

This looks like intentional?  It's probably better to to do a literal
"return 0;"  Makes the static checkers happy.

c567552612ece7 Anna Schumaker  2014-05-28  1132  
d3b00a802c845a Anna Schumaker  2022-07-21  1133  	segs = kmalloc_array(segments, sizeof(*segs), GFP_KERNEL);
d3b00a802c845a Anna Schumaker  2022-07-21  1134  	if (!segs)
d3b00a802c845a Anna Schumaker  2022-07-21  1135  		return -ENOMEM;
c567552612ece7 Anna Schumaker  2014-05-28  1136  
d3b00a802c845a Anna Schumaker  2022-07-21  1137  	xdr_set_scratch_buffer(xdr, &scratch_buf, 32);
d3b00a802c845a Anna Schumaker  2022-07-21  1138  	status = -EIO;

This assignment is not used.

d3b00a802c845a Anna Schumaker  2022-07-21  1139  	for (i = 0; i < segments; i++) {
d3b00a802c845a Anna Schumaker  2022-07-21  1140  		status = decode_read_plus_segment(xdr, &segs[i]);
bff049a3b5001e Anna Schumaker  2020-04-01  1141  		if (status < 0)
d3b00a802c845a Anna Schumaker  2022-07-21  1142  			goto out;
bff049a3b5001e Anna Schumaker  2020-04-01  1143  	}
c567552612ece7 Anna Schumaker  2014-05-28  1144  
d3b00a802c845a Anna Schumaker  2022-07-21  1145  	xdr_set_pagelen(xdr, xdr_align_size(args->count));
d3b00a802c845a Anna Schumaker  2022-07-21  1146  	for (i = segments; i > 0; i--)
d3b00a802c845a Anna Schumaker  2022-07-21 @1147  		res->count += process_read_plus_segment(xdr, args, res, &segs[i-1]);
d3b00a802c845a Anna Schumaker  2022-07-21  1148  	status = 0;
d3b00a802c845a Anna Schumaker  2022-07-21  1149  
c567552612ece7 Anna Schumaker  2014-05-28  1150  out:
d3b00a802c845a Anna Schumaker  2022-07-21  1151  	kfree(segs);
d3b00a802c845a Anna Schumaker  2022-07-21  1152  	return status;
c567552612ece7 Anna Schumaker  2014-05-28  1153  }

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