multiple xlators: strncpy()->sprintf(), reduce strlen()'s

xlators/cluster/afr/src/afr-common.c
xlators/cluster/dht/src/dht-common.c
xlators/cluster/dht/src/dht-rebalance.c
xlators/cluster/stripe/src/stripe-helpers.c

strncpy may not be very efficient for short strings copied into
a large buffer: If the length of src is less than n,
strncpy() writes additional null bytes to dest to ensure
that a total of n bytes are written.

Instead, use snprintf().
Also:
- save the result of strlen() and re-use it when possible.
- move from strlen to SLEN (sizeof() ) for const strings.

Compile-tested only!

Change-Id: Icdf79dd3d9f9ff120e4720ff2b8bd016df575c38
updates: bz#1193929
Signed-off-by: Yaniv Kaul <ykaul@redhat.com>

4 files changed, 30 insertions, 33 deletions

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index 641485b1ed0..3a32ebc31a4 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -2178,7 +2178,7 @@ afr_is_xattr_ignorable (char *key)
 {
         int i = 0;
 
-        if (!strncmp (key, AFR_XATTR_PREFIX, strlen(AFR_XATTR_PREFIX)))
+        if (!strncmp (key, AFR_XATTR_PREFIX, SLEN (AFR_XATTR_PREFIX)))
                 return _gf_true;
         for (i = 0; afr_ignore_xattrs[i]; i++) {
                 if (!strcmp (key, afr_ignore_xattrs[i]))
@@ -6212,7 +6212,6 @@ afr_get_heal_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
         dict_t         *dict              = NULL;
         int             ret               = -1;
         int             op_errno          = 0;
-        int             size              = 0;
         inode_t        *inode             = NULL;
         char           *substr            = NULL;
         char           *status            = NULL;
@@ -6229,21 +6228,18 @@ afr_get_heal_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
         }
 
         if (pending) {
-                size = strlen ("-pending") + 1;
                 gf_asprintf (&substr, "-pending");
                 if (!substr)
                         goto out;
         }
 
         if (ret == -EIO) {
-                size += strlen ("split-brain") + 1;
                 ret = gf_asprintf (&status, "split-brain%s",
                                    substr? substr : "");
                 if (ret < 0)
                         goto out;
                 dict = afr_set_heal_info (status);
         } else if (ret == -EAGAIN) {
-                size += strlen ("possibly-healing") + 1;
                 ret = gf_asprintf (&status, "possibly-healing%s",
                                    substr? substr : "");
                 if (ret < 0)
@@ -6258,7 +6254,6 @@ afr_get_heal_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
                     !metadata_selfheal) {
                         dict = afr_set_heal_info ("no-heal");
                 } else {
-                        size += strlen ("heal") + 1;
                         ret = gf_asprintf (&status, "heal%s",
                                            substr? substr : "");
                         if (ret < 0)
@@ -6275,7 +6270,6 @@ afr_get_heal_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
                  */
                 if (data_selfheal || entry_selfheal ||
                     metadata_selfheal) {
-                        size += strlen ("heal") + 1;
                         ret = gf_asprintf (&status, "heal%s",
                                            substr? substr : "");
                         if (ret < 0)
@@ -6409,13 +6403,13 @@ afr_get_split_brain_status (void *opaque)
         }
 
         /* Calculation for string length :
-        * (child_count X length of child-name) + strlen ("    Choices :")
+        * (child_count X length of child-name) + SLEN ("    Choices :")
         * child-name consists of :
         * a) 251 = max characters for volname according to GD_VOLUME_NAME_MAX
         * b) strlen ("-client-00,") assuming 16 replicas
         */
-        choices = alloca0 (priv->child_count * (251 + sizeof("-client-00,")) +
-                           sizeof("    Choices:"));
+        choices = alloca0 (priv->child_count * (256 + SLEN ("-client-00,")) +
+                           SLEN ("    Choices:"));
 
         ret = afr_is_split_brain (frame, this, inode, loc->gfid, &d_spb,
                                   &m_spb);
@@ -6717,6 +6711,7 @@ afr_serialize_xattrs_with_delimiter (call_frame_t *frame, xlator_t *this,
         char          *xattr     = NULL;
         int            i         = 0;
         int            len       = 0;
+        size_t         str_len   = 0;
         int            ret       = -1;
 
         priv = this->private;
@@ -6724,8 +6719,9 @@ afr_serialize_xattrs_with_delimiter (call_frame_t *frame, xlator_t *this,
 
         for (i = 0; i < priv->child_count; i++) {
                 if (!local->replies[i].valid || local->replies[i].op_ret) {
-                        buf = strncat (buf, default_str, strlen (default_str));
-                        len += strlen (default_str);
+                        str_len = strlen (default_str);
+                        buf = strncat (buf, default_str, str_len);
+                        len += str_len;
                         buf[len++] = delimiter;
                         buf[len] = '\0';
                 } else {
@@ -6738,8 +6734,9 @@ afr_serialize_xattrs_with_delimiter (call_frame_t *frame, xlator_t *this,
                                         "%d", i);
                                 goto out;
                         }
-                        buf = strncat (buf, xattr, strlen (xattr));
-                        len += strlen (xattr);
+                        str_len = strlen (xattr);
+                        buf = strncat (buf, xattr, str_len);
+                        len += str_len;
                         buf[len++] = delimiter;
                         buf[len] = '\0';
                 }
diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index c7c7fbf22ba..69555a22e5e 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -428,7 +428,7 @@ dht_aggregate (dict_t *this, char *key, data_t *value, void *data)
                 goto out;
         } else {
                 /* compare user xattrs only */
-                if (!strncmp (key, "user.", strlen ("user."))) {
+                if (!strncmp (key, "user.", SLEN ("user."))) {
                         ret = dict_lookup (dst, key, &dict_data);
                         if (!ret && dict_data && value) {
                                 ret = is_data_equal (dict_data, value);
@@ -4379,7 +4379,7 @@ dht_vgetxattr_alloc_and_fill (dht_local_t *local, dict_t *xattr, xlator_t *this,
         local->alloc_len += strlen(value);
 
         if (!local->xattr_val) {
-                local->alloc_len += sizeof (DHT_PATHINFO_HEADER) + 10;
+                local->alloc_len += (SLEN (DHT_PATHINFO_HEADER) + 10);
                 local->xattr_val = GF_MALLOC (local->alloc_len,
                                               gf_common_mt_char);
                 if (!local->xattr_val) {
@@ -5189,8 +5189,9 @@ dht_getxattr (call_frame_t *frame, xlator_t *this,
         if (!DHT_IS_DIR(layout))
                 goto no_dht_is_dir;
 
-        if (strncmp (key, GF_XATTR_GET_REAL_FILENAME_KEY,
-                     strlen (GF_XATTR_GET_REAL_FILENAME_KEY)) == 0) {
+        if ((strncmp (key, GF_XATTR_GET_REAL_FILENAME_KEY,
+                      SLEN (GF_XATTR_GET_REAL_FILENAME_KEY)) == 0)
+            && DHT_IS_DIR(layout)) {
                 dht_getxattr_get_real_filename (frame, this, loc, key, xdata);
                 return 0;
         }
@@ -5442,7 +5443,7 @@ dht_fgetxattr (call_frame_t *frame, xlator_t *this,
         if ((fd->inode->ia_type == IA_IFDIR)
             && key
             && (strncmp (key, GF_XATTR_LOCKINFO_KEY,
-                         strlen (GF_XATTR_LOCKINFO_KEY)) != 0)) {
+                         SLEN (GF_XATTR_LOCKINFO_KEY)) != 0)) {
                 local->call_cnt = conf->subvolume_cnt;
                 cnt             = conf->subvolume_cnt;
                 ret = dht_inode_ctx_mdsvol_get (fd->inode, this, &mds_subvol);
@@ -6165,7 +6166,7 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
                         goto err;
                 }
 
-                memcpy (value, tmp->data, ((tmp->len < 4095) ? tmp->len : 4095));
+                memcpy (value, tmp->data, min (tmp->len, 4095));
                 local->key = gf_strdup (value);
                 local->call_cnt = conf->subvolume_cnt;
 
@@ -6214,7 +6215,7 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
         tmp = dict_get (xattr, "distribute.directory-spread-count");
         if (tmp) {
                 /* Setxattr value is packed as 'binary', not string */
-                memcpy (value, tmp->data, ((tmp->len < 4095)?tmp->len:4095));
+                memcpy (value, tmp->data, min (tmp->len, 4095));
                 ret = gf_string2uint32 (value, &dir_spread);
                 if (!ret && ((dir_spread <= conf->subvolume_cnt) &&
                              (dir_spread > 0))) {
@@ -11422,7 +11423,6 @@ dht_log_new_layout_for_dir_selfheal (xlator_t *this, loc_t *loc,
         int                                i = 0;
         gf_loglevel_t             log_level = gf_log_get_loglevel();
         int                              ret = 0;
-        int                   max_string_len = 0;
 
         if (log_level < GF_LOG_INFO)
                 return;
@@ -11439,9 +11439,7 @@ dht_log_new_layout_for_dir_selfheal (xlator_t *this, loc_t *loc,
         if (!loc->path)
                 return;
 
-        max_string_len = sizeof (string);
-
-        ret = snprintf (string, max_string_len, "Setting layout of %s with ",
+        ret = snprintf (string, sizeof (string), "Setting layout of %s with ",
                         loc->path);
 
         if (ret < 0)
@@ -11461,7 +11459,7 @@ dht_log_new_layout_for_dir_selfheal (xlator_t *this, loc_t *loc,
 
         for (i = 0; i < layout->cnt; i++) {
 
-                ret  = snprintf (string, max_string_len,
+                ret  = snprintf (string, sizeof (string),
                                  "[Subvol_name: %s, Err: %d , Start: "
                                  "%"PRIu32 " , Stop: %"PRIu32 " , Hash: %"
                                  PRIu32 " ], ",
diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c
index ed61880c8e4..9983429acec 100644
--- a/xlators/cluster/dht/src/dht-rebalance.c
+++ b/xlators/cluster/dht/src/dht-rebalance.c
@@ -147,12 +147,12 @@ dht_send_rebalance_event (xlator_t *this, int cmd, gf_defrag_status_t status)
                 volname = defrag->tier_conf.volname;
         } else {
                 /* DHT volume */
-                len = strlen (this->name);
+                len = strlen (this->name) - strlen (suffix);
                 tmpstr = gf_strdup (this->name);
                 if (tmpstr) {
-                        ptr = tmpstr + (len - strlen (suffix));
+                        ptr = tmpstr + len;
                         if (!strcmp (ptr, suffix)) {
-                                tmpstr[len - strlen (suffix)] = '\0';
+                                tmpstr[len] = '\0';
                                 volname = tmpstr;
                         }
                 }
diff --git a/xlators/cluster/stripe/src/stripe-helpers.c b/xlators/cluster/stripe/src/stripe-helpers.c
index 71ab608118f..59dfdfad979 100644
--- a/xlators/cluster/stripe/src/stripe-helpers.c
+++ b/xlators/cluster/stripe/src/stripe-helpers.c
@@ -253,6 +253,7 @@ stripe_fill_pathinfo_xattr (xlator_t *this, stripe_local_t *local,
         int      ret             = -1;
         int32_t  padding         = 0;
         int32_t  tlen            = 0;
+        int      len             = 0;
         char stripe_size_str[20] = {0,};
         char    *pathinfo_serz   = NULL;
 
@@ -261,12 +262,13 @@ stripe_fill_pathinfo_xattr (xlator_t *this, stripe_local_t *local,
                 goto out;
         }
 
-        (void) snprintf (stripe_size_str, sizeof (stripe_size_str), "%"PRId64,
+        len = snprintf (stripe_size_str, sizeof (stripe_size_str), "%"PRId64,
                          (long long) (local->fctx) ? local->fctx->stripe_size : 0);
-
+        if (len < 0 || len >= sizeof (stripe_size_str))
+                goto out;
         /* extra bytes for decorations (brackets and <>'s) */
-        padding = strlen (this->name) + strlen (STRIPE_PATHINFO_HEADER)
-                + strlen (stripe_size_str) + 7;
+        padding = strlen (this->name) + SLEN (STRIPE_PATHINFO_HEADER)
+                  + len + 7;
         local->xattr_total_len += (padding + 2);
 
         pathinfo_serz = GF_MALLOC (local->xattr_total_len,