[PATCH 5/5] 9p: remove dead stores (variable set again without being read)

From: Dominique Martinet
Date: Thu Apr 27 2023 - 07:24:27 EST

Next message: Mark Rutland: "Re: [External] Re: [PATCH] firmware: added a firmware information passing method FFI"
Previous message: Dominique Martinet: "[PATCH 3/5] 9p: virtio: make sure 'offs' is initialized in zc_request"
In reply to: Dominique Martinet: "[PATCH 3/5] 9p: virtio: make sure 'offs' is initialized in zc_request"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

The 9p code for some reason used to initialize variables outside of the
declaration, e.g. instead of just initializing the variable like this:

int retval = 0

We would be doing this:

int retval;
retval = 0;

This is perfectly fine and the compiler will just optimize dead stores
anyway, but scan-build seems to think this is a problem and there are
many of these warnings making the output of scan-build full of such
warnings:
fs/9p/vfs_inode.c:916:2: warning: Value stored to 'retval' is never read [deadcode.DeadStores]
retval = 0;
^ ~

I have no strong opinion here, but if we want to regularily run
scan-build we should fix these just to silence the messages.

I've confirmed these all are indeed ok to remove.

Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
---
fs/9p/vfs_inode.c | 6 ------
fs/9p/vfs_inode_dotl.c | 1 -
net/9p/client.c | 46 ++++++++++++----------------------------------
3 files changed, 12 insertions(+), 41 deletions(-)

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 54dfe4f10f43..82589d1d9bbe 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -164,7 +164,6 @@ int v9fs_uflags2omode(int uflags, int extended)
{
int ret;

- ret = 0;
switch (uflags&3) {
default:
case O_RDONLY:
@@ -604,7 +603,6 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,

p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);

- err = 0;
name = dentry->d_name.name;
dfid = v9fs_parent_fid(dentry);
if (IS_ERR(dfid)) {
@@ -816,8 +814,6 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
if (!(flags & O_CREAT) || d_really_is_positive(dentry))
return finish_no_open(file, res);

- err = 0;
-
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode);
p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
@@ -913,7 +909,6 @@ v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
return -EINVAL;

p9_debug(P9_DEBUG_VFS, "\n");
- retval = 0;
old_inode = d_inode(old_dentry);
new_inode = d_inode(new_dentry);
v9ses = v9fs_inode2v9ses(old_inode);
@@ -1067,7 +1062,6 @@ static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
if (retval)
return retval;

- retval = -EPERM;
v9ses = v9fs_dentry2v9ses(dentry);
if (iattr->ia_valid & ATTR_FILE) {
fid = iattr->ia_file->private_data;
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index f9371b5b70ea..df7023af17cf 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -367,7 +367,6 @@ static int v9fs_vfs_mkdir_dotl(struct mnt_idmap *idmap,
struct posix_acl *dacl = NULL, *pacl = NULL;

p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
- err = 0;
v9ses = v9fs_inode2v9ses(dir);

omode |= S_IFDIR;
diff --git a/net/9p/client.c b/net/9p/client.c
index a3340268ec8d..86bbc7147fc1 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -904,7 +904,7 @@ EXPORT_SYMBOL(do_trace_9p_fid_put);

static int p9_client_version(struct p9_client *c)
{
- int err = 0;
+ int err;
struct p9_req_t *req;
char *version = NULL;
int msize;
@@ -975,7 +975,6 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
struct p9_client *clnt;
char *client_id;

- err = 0;
clnt = kmalloc(sizeof(*clnt), GFP_KERNEL);
if (!clnt)
return ERR_PTR(-ENOMEM);
@@ -1094,7 +1093,7 @@ struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
const char *uname, kuid_t n_uname,
const char *aname)
{
- int err = 0;
+ int err;
struct p9_req_t *req;
struct p9_fid *fid;
struct p9_qid qid;
@@ -1147,7 +1146,6 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
struct p9_req_t *req;
u16 nwqids, count;

- err = 0;
wqids = NULL;
clnt = oldfid->clnt;
if (clone) {
@@ -1224,7 +1222,6 @@ int p9_client_open(struct p9_fid *fid, int mode)
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
- err = 0;

if (fid->mode != -1)
return -EINVAL;
@@ -1262,7 +1259,7 @@ EXPORT_SYMBOL(p9_client_open);
int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags,
u32 mode, kgid_t gid, struct p9_qid *qid)
{
- int err = 0;
+ int err;
struct p9_client *clnt;
struct p9_req_t *req;
int iounit;
@@ -1314,7 +1311,6 @@ int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,

p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
fid->fid, name, perm, mode);
- err = 0;
clnt = fid->clnt;

if (fid->mode != -1)
@@ -1350,7 +1346,7 @@ EXPORT_SYMBOL(p9_client_fcreate);
int p9_client_symlink(struct p9_fid *dfid, const char *name,
const char *symtgt, kgid_t gid, struct p9_qid *qid)
{
- int err = 0;
+ int err;
struct p9_client *clnt;
struct p9_req_t *req;

@@ -1402,13 +1398,12 @@ EXPORT_SYMBOL(p9_client_link);

int p9_client_fsync(struct p9_fid *fid, int datasync)
{
- int err;
+ int err = 0;
struct p9_client *clnt;
struct p9_req_t *req;

p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
fid->fid, datasync);
- err = 0;
clnt = fid->clnt;

req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
@@ -1428,7 +1423,7 @@ EXPORT_SYMBOL(p9_client_fsync);

int p9_client_clunk(struct p9_fid *fid)
{
- int err;
+ int err = 0;
struct p9_client *clnt;
struct p9_req_t *req;
int retries = 0;
@@ -1436,7 +1431,6 @@ int p9_client_clunk(struct p9_fid *fid)
again:
p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n",
fid->fid, retries);
- err = 0;
clnt = fid->clnt;

req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
@@ -1465,12 +1459,11 @@ EXPORT_SYMBOL(p9_client_clunk);

int p9_client_remove(struct p9_fid *fid)
{
- int err;
+ int err = 0;
struct p9_client *clnt;
struct p9_req_t *req;

p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
- err = 0;
clnt = fid->clnt;

req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
@@ -1680,7 +1673,6 @@ struct p9_wstat *p9_client_stat(struct p9_fid *fid)
if (!ret)
return ERR_PTR(-ENOMEM);

- err = 0;
clnt = fid->clnt;

req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
@@ -1733,7 +1725,6 @@ struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
if (!ret)
return ERR_PTR(-ENOMEM);

- err = 0;
clnt = fid->clnt;

req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
@@ -1812,11 +1803,10 @@ static int p9_client_statsize(struct p9_wstat *wst, int proto_version)

int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
{
- int err;
+ int err = 0;
struct p9_req_t *req;
struct p9_client *clnt;

- err = 0;
clnt = fid->clnt;
wst->size = p9_client_statsize(wst, clnt->proto_version);
p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n",
@@ -1851,11 +1841,10 @@ EXPORT_SYMBOL(p9_client_wstat);

int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
{
- int err;
+ int err = 0;
struct p9_req_t *req;
struct p9_client *clnt;

- err = 0;
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
p9_debug(P9_DEBUG_9P, " valid=%x mode=%x uid=%d gid=%d size=%lld\n",
@@ -1887,7 +1876,6 @@ int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
struct p9_req_t *req;
struct p9_client *clnt;

- err = 0;
clnt = fid->clnt;

p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
@@ -1921,11 +1909,10 @@ EXPORT_SYMBOL(p9_client_statfs);
int p9_client_rename(struct p9_fid *fid,
struct p9_fid *newdirfid, const char *name)
{
- int err;
+ int err = 0;
struct p9_req_t *req;
struct p9_client *clnt;

- err = 0;
clnt = fid->clnt;

p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
@@ -1949,11 +1936,10 @@ EXPORT_SYMBOL(p9_client_rename);
int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
struct p9_fid *newdirfid, const char *new_name)
{
- int err;
+ int err = 0;
struct p9_req_t *req;
struct p9_client *clnt;

- err = 0;
clnt = olddirfid->clnt;

p9_debug(P9_DEBUG_9P,
@@ -1986,7 +1972,6 @@ struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
struct p9_client *clnt;
struct p9_fid *attr_fid;

- err = 0;
clnt = file_fid->clnt;
attr_fid = p9_fid_create(clnt);
if (!attr_fid) {
@@ -2027,14 +2012,13 @@ EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
u64 attr_size, int flags)
{
- int err;
+ int err = 0;
struct p9_req_t *req;
struct p9_client *clnt;

p9_debug(P9_DEBUG_9P,
">>> TXATTRCREATE fid %d name %s size %llu flag %d\n",
fid->fid, name, attr_size, flags);
- err = 0;
clnt = fid->clnt;
req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
fid->fid, name, attr_size, flags);
@@ -2063,7 +2047,6 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
fid->fid, offset, count);

- err = 0;
clnt = fid->clnt;

rsize = fid->iounit;
@@ -2122,7 +2105,6 @@ int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
struct p9_client *clnt;
struct p9_req_t *req;

- err = 0;
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P,
">>> TMKNOD fid %d name %s mode %d major %d minor %d\n",
@@ -2153,7 +2135,6 @@ int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
struct p9_client *clnt;
struct p9_req_t *req;

- err = 0;
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
fid->fid, name, mode, from_kgid(&init_user_ns, gid));
@@ -2182,7 +2163,6 @@ int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
struct p9_client *clnt;
struct p9_req_t *req;

- err = 0;
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P,
">>> TLOCK fid %d type %i flags %d start %lld length %lld proc_id %d client_id %s\n",
@@ -2214,7 +2194,6 @@ int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
struct p9_client *clnt;
struct p9_req_t *req;

- err = 0;
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P,
">>> TGETLOCK fid %d, type %i start %lld length %lld proc_id %d client_id %s\n",
@@ -2251,7 +2230,6 @@ int p9_client_readlink(struct p9_fid *fid, char **target)
struct p9_client *clnt;
struct p9_req_t *req;

- err = 0;
clnt = fid->clnt;
p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);

--
2.39.2

Next message: Mark Rutland: "Re: [External] Re: [PATCH] firmware: added a firmware information passing method FFI"
Previous message: Dominique Martinet: "[PATCH 3/5] 9p: virtio: make sure 'offs' is initialized in zc_request"
In reply to: Dominique Martinet: "[PATCH 3/5] 9p: virtio: make sure 'offs' is initialized in zc_request"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]