Include custom partitions in dumpcache tool

Currently dumpcache use whitelist to include only standard partitions
and also print duplicated entries with symbolic link which makes the
total summary inaccurate.
This patch use blacklist "rootfs/devfs/tmpfs/procfs" to support more
partitions and skip symbolic links.

Test: manual - took a dumpcache
Bug: 31756965
Change-Id: I6038de9a2f3be11179cb30b4c4c6d2e7cd43aaa6

1 files changed, 35 insertions, 19 deletions

diff --git a/pagecache/dumpcache.c b/pagecache/dumpcache.c
index eb11bba5..4503a6e6 100644
--- a/pagecache/dumpcache.c
+++ b/pagecache/dumpcache.c
@@ -9,6 +9,7 @@
 
 #include <ctype.h>
 #include <stddef.h>
+#include <mntent.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 
@@ -72,12 +73,12 @@ static struct file_info *get_file_info(const char* fpath, size_t file_size) {
 }
 
 static int store_num_cached(const char* fpath, const struct stat *sb) {
-    int fd;
+    int fd, ret = -1;
     fd = open (fpath, O_RDONLY);
 
     if (fd == -1) {
-        printf("Could not open file.");
-        return -1;
+        fprintf(stderr, "Could not open file: %s\n", fpath);
+        return ret;
     }
 
     void* mapped_addr = mmap(NULL, sb->st_size, PROT_NONE, MAP_SHARED, fd, 0);
@@ -86,25 +87,28 @@ static int store_num_cached(const char* fpath, const struct stat *sb) {
         // Calculate bit-vector size
         size_t num_file_pages = (sb->st_size + g_page_size - 1) / g_page_size;
         unsigned char* mincore_data = calloc(1, num_file_pages);
-        int ret = mincore(mapped_addr, sb->st_size, mincore_data);
-        int num_cached = 0;
-        unsigned int page = 0;
-        for (page = 0; page < num_file_pages; page++) {
-           if (mincore_data[page]) num_cached++;
-        }
-        if (num_cached > 0) {
-            struct file_info *info = get_file_info(fpath, sb->st_size);
-            info->num_cached_pages += num_cached;
-            g_total_cached += num_cached;
+        ret = mincore(mapped_addr, sb->st_size, mincore_data);
+        if (!ret) {
+            int num_cached = 0;
+            unsigned int page = 0;
+            for (page = 0; page < num_file_pages; page++) {
+                if (mincore_data[page]) num_cached++;
+            }
+            if (num_cached > 0) {
+                struct file_info *info = get_file_info(fpath, sb->st_size);
+                info->num_cached_pages += num_cached;
+                g_total_cached += num_cached;
+            }
         }
         munmap(mapped_addr, sb->st_size);
     }
 
     close(fd);
-    return 0;
+    return ret;
 }
 
-static int scan_entry(const char *fpath, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
+static int scan_entry(const char *fpath, const struct stat *sb, int typeflag,
+                      struct FTW * __attribute__((unused))ftwbuf) {
     if (typeflag == FTW_F) {
         store_num_cached(fpath, sb);
     }
@@ -130,10 +134,22 @@ int main()
     g_files = malloc(INITIAL_NUM_FILES * sizeof(struct file_info*));
     g_files_size = INITIAL_NUM_FILES;
 
-    // Walk filesystem trees
-    nftw("/system/", &scan_entry, MAX_NUM_FD, 0);
-    nftw("/vendor/", &scan_entry, MAX_NUM_FD, 0);
-    nftw("/data/", &scan_entry, MAX_NUM_FD, 0);
+    // Walk filesystem trees through procfs except rootfs/devfs/sysfs/procfs
+    FILE* fp = setmntent("/proc/mounts", "r");
+    if (fp == NULL) {
+        fprintf(stderr, "Error opening /proc/mounts\n");
+        return -errno;
+    }
+    struct mntent* mentry;
+    while ((mentry = getmntent(fp)) != NULL) {
+        if (strcmp(mentry->mnt_type, "rootfs") != 0 &&
+            strncmp("/dev", mentry->mnt_dir, strlen("/dev")) != 0 &&
+            strncmp("/sys", mentry->mnt_dir, strlen("/sys")) != 0 &&
+            strncmp("/proc", mentry->mnt_dir, strlen("/proc")) != 0) {
+            nftw(mentry->mnt_dir, &scan_entry, MAX_NUM_FD, FTW_MOUNT | FTW_PHYS | FTW_DEPTH);
+        }
+    }
+    endmntent(fp);
 
     // Sort entries
     qsort(g_files, g_num_files, sizeof(g_files[0]), &cmpfiles);