libbb: shrink recursive_action() by reducing memory pressure

function                                             old     new   delta
recursive_action1                                      -     316    +316
file_action_grep                                     161     164      +3
add_to_prg_cache_if_socket                           202     205      +3
depmod_main                                          509     511      +2
writeFileToTarball                                   488     489      +1
parse_module                                         281     282      +1
fileAction                                           207     208      +1
act                                                  189     190      +1
add_to_dirlist                                        65      64      -1
writeTarFile                                         196     194      -2
uuidcache_init                                        47      45      -2
uuidcache_check_device                               109     107      -2
true_action                                            8       6      -2
run_parts_main                                       310     308      -2
netstat_main                                         534     532      -2
lsusb_main                                            29      27      -2
lspci_main                                            45      43      -2
initial_scan                                         138     136      -2
grep_main                                            845     843      -2
find_main                                            482     480      -2
config_file_action                                   437     435      -2
chmod_main                                           142     140      -2
dirAction                                             14      10      -4
diff_main                                           1544    1540      -4
chown_main                                           154     148      -6
skip_dir                                             136     129      -7
dir_act                                              191     184      -7
recursive_action                                     453      69    -384
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 7/20 up/down: 328/-439)        Total: -111 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

4 files changed, 24 insertions, 31 deletions

diff --git a/util-linux/lspci.c b/util-linux/lspci.c
index 2f0b5fab9..c22cbcc1e 100644
--- a/util-linux/lspci.c
+++ b/util-linux/lspci.c
@@ -37,11 +37,9 @@ enum {
 /*
  * PCI_SLOT_NAME PCI_CLASS: PCI_VID:PCI_DID [PCI_SUBSYS_VID:PCI_SUBSYS_DID] [DRIVER]
  */
-static int FAST_FUNC fileAction(
+static int FAST_FUNC fileAction(struct recursive_state *state UNUSED_PARAM,
                 const char *fileName,
-                struct stat *statbuf UNUSED_PARAM,
-                void *userData UNUSED_PARAM,
-                int depth UNUSED_PARAM)
+                struct stat *statbuf UNUSED_PARAM)
 {
         parser_t *parser;
         char *tokens[3];
@@ -117,8 +115,7 @@ int lspci_main(int argc UNUSED_PARAM, char **argv)
                         ACTION_RECURSE,
                         fileAction,
                         NULL, /* dirAction */
-                        NULL, /* userData */
-                        0 /* depth */);
-
+                        NULL /* userData */
+        );
         return EXIT_SUCCESS;
 }
diff --git a/util-linux/lsusb.c b/util-linux/lsusb.c
index 64a00eee2..9abb748ce 100644
--- a/util-linux/lsusb.c
+++ b/util-linux/lsusb.c
@@ -24,11 +24,9 @@
 
 #include "libbb.h"
 
-static int FAST_FUNC fileAction(
+static int FAST_FUNC fileAction(struct recursive_state *state UNUSED_PARAM,
                 const char *fileName,
-                struct stat *statbuf UNUSED_PARAM,
-                void *userData UNUSED_PARAM,
-                int depth UNUSED_PARAM)
+                struct stat *statbuf UNUSED_PARAM)
 {
         parser_t *parser;
         char *tokens[4];
@@ -80,8 +78,8 @@ int lsusb_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                         ACTION_RECURSE,
                         fileAction,
                         NULL, /* dirAction */
-                        NULL, /* userData */
-                        0 /* depth */);
+                        NULL /* userData */
+        );
 
         return EXIT_SUCCESS;
 }
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index f42bebc20..59dbcf0cd 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -845,13 +845,12 @@ static ssize_t readlink2(char *buf, size_t bufsize)
 /* File callback for /sys/ traversal.
  * We act only on "/sys/.../dev" (pseudo)file
  */
-static int FAST_FUNC fileAction(const char *fileName,
-                struct stat *statbuf UNUSED_PARAM,
-                void *userData,
-                int depth UNUSED_PARAM)
+static int FAST_FUNC fileAction(struct recursive_state *state,
+                const char *fileName,
+                struct stat *statbuf UNUSED_PARAM)
 {
         size_t len = strlen(fileName) - 4; /* can't underflow */
-        char *path = userData;  /* char array[PATH_MAX + SCRATCH_SIZE] */
+        char *path = state->userData;   /* char array[PATH_MAX + SCRATCH_SIZE] */
         char subsys[PATH_MAX];
         int res;
 
@@ -888,12 +887,11 @@ static int FAST_FUNC fileAction(const char *fileName,
 }
 
 /* Directory callback for /sys/ traversal */
-static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
-                struct stat *statbuf UNUSED_PARAM,
-                void *userData UNUSED_PARAM,
-                int depth)
+static int FAST_FUNC dirAction(struct recursive_state *state,
+                const char *fileName UNUSED_PARAM,
+                struct stat *statbuf UNUSED_PARAM)
 {
-        return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
+        return (state->depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
 }
 
 /* For the full gory details, see linux/Documentation/firmware_class/README
@@ -1149,7 +1147,7 @@ static void initial_scan(char *temp)
         /* Create all devices from /sys/dev hierarchy */
         recursive_action("/sys/dev",
                          ACTION_RECURSE | ACTION_FOLLOWLINKS,
-                         fileAction, dirAction, temp, 0);
+                         fileAction, dirAction, temp);
 }
 
 #if ENABLE_FEATURE_MDEV_DAEMON
diff --git a/util-linux/volume_id/get_devname.c b/util-linux/volume_id/get_devname.c
index 34f5d119f..00cfb2826 100644
--- a/util-linux/volume_id/get_devname.c
+++ b/util-linux/volume_id/get_devname.c
@@ -102,10 +102,9 @@ uuidcache_addentry(char *device, /*int major, int minor,*/ char *label, char *uu
  * add a cache entry for this device.
  * If device node does not exist, it will be temporarily created. */
 static int FAST_FUNC
-uuidcache_check_device(const char *device,
-                struct stat *statbuf,
-                void *userData UNUSED_PARAM,
-                int depth UNUSED_PARAM)
+uuidcache_check_device(struct recursive_state *state UNUSED_PARAM,
+                const char *device,
+                struct stat *statbuf)
 {
         /* note: this check rejects links to devices, among other nodes */
         if (!S_ISBLK(statbuf->st_mode)
@@ -145,12 +144,13 @@ uuidcache_init(int scan_devices)
          * This is unacceptably complex. Let's just scan /dev.
          * (Maybe add scanning of /sys/block/XXX/dev for devices
          * somehow not having their /dev/XXX entries created?) */
-        if (scan_devices)
+        if (scan_devices) {
                 recursive_action("/dev", ACTION_RECURSE,
                         uuidcache_check_device, /* file_action */
                         NULL, /* dir_action */
-                        NULL, /* userData */
-                        0 /* depth */);
+                        NULL /* userData */
+                );
+        }
 
         return uuidCache;
 }