AOSP: misc: use scandir with alphasort instead of readdir for consistency

During the image generation, When using the e2fsdroid with src_dir,
then dir files are listed with readdir, which will not guarantee
the order across the machines/fielsystems. So instead using the
scandir with alphasort option to list the files in sorted order.

Bug: 122874817

Change-Id: I4b946c737319252b82c74a0e10360843503862a1
From AOSP commit: 4cbe059b48b46d6657e24e4cdef543da7537dba3

Reported-by: Yasuhiro Kubota <yasuhiro.1.kubota@sony.com>
Tested-by: Yasuhiro Kubota <yasuhiro.1.kubota@sony.com>
Signed-off-by: Vikram Dattu Thota <vikram.dattu@sony.com>
Signed-off-by: Takuya Ogawa <takuya.ogawa@sony.com>
Signed-off-by: Yoshitaka Seto <yoshitaka.seto@sony.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/misc/create_inode.c b/misc/create_inode.c
index b288935d79f4f288638ac5d54b27a6824a2fbe61..0091b7237f414ca15d5670ba7aacaf17c4fd5c48 100644 (file)
--- a/misc/create_inode.c
+++ b/misc/create_inode.c
@@ -19,6 +19,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <limits.h> /* for PATH_MAX */
+#include <dirent.h> /* for scandir() and alphasort() */
 #if defined HAVE_SYS_XATTR_H
 #include <sys/xattr.h>
 #elif defined HAVE_ATTR_XATTR_H
@@ -717,7 +718,69 @@ static errcode_t path_append(struct file_info *target, const char *file)
        return 0;
 }
 
-/* Copy files from source_dir to fs */
+#ifdef _WIN32
+static int scandir(const char *dir_name, struct dirent ***name_list,
+                  int (*filter)(const struct dirent*),
+                  int (*compar)(const struct dirent**, const struct dirent**)) {
+       DIR *dir;
+       struct dirent *dent;
+       struct dirent **temp_list = NULL;
+       size_t temp_list_size = 0; // unit: num of dirent
+       size_t num_dent = 0;
+
+       dir = opendir(dir_name);
+       if (dir == NULL) {
+               return -1;
+       }
+
+       while ((dent = readdir(dir))) {
+               if (filter != NULL && !(*filter)(dent))
+                       continue;
+
+               // re-allocate the list
+               if (num_dent == temp_list_size) {
+                       size_t new_list_size = temp_list_size + 32;
+                       struct dirent **new_list = (struct dirent**)realloc(
+                               temp_list, new_list_size * sizeof(struct dirent*));
+                       if (new_list == NULL) {
+                               goto out;
+                       }
+                       temp_list_size = new_list_size;
+                       temp_list = new_list;
+               }
+               // add the copy of dirent to the list
+               temp_list[num_dent] = (struct dirent*)malloc((dent->d_reclen + 3) & ~3);
+               memcpy(temp_list[num_dent], dent, dent->d_reclen);
+               num_dent++;
+       }
+
+       if (compar != NULL) {
+               qsort(temp_list, num_dent, sizeof(struct dirent*),
+                     (int (*)(const void*, const void*))compar);
+       }
+
+        // release the temp list
+       *name_list = temp_list;
+       temp_list = NULL;
+
+out:
+       if (temp_list != NULL) {
+               while (num_dent > 0) {
+                       free(temp_list[--num_dent]);
+               }
+               free(temp_list);
+               num_dent = -1;
+       }
+       closedir(dir);
+       return num_dent;
+}
+
+static int alphasort(const struct dirent **a, const struct dirent **b) {
+       return strcoll((*a)->d_name, (*b)->d_name);
+}
+#endif
+
+/* Copy files from source_dir to fs in alphabetical order */
 static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
                               const char *source_dir, ext2_ino_t root,
                               struct hdlinks_s *hdlinks,
@@ -725,8 +788,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
                               struct fs_ops_callbacks *fs_callbacks)
 {
        const char      *name;
-       DIR             *dh;
-       struct dirent   *dent;
+       struct dirent   **dent;
        struct stat     st;
        char            *ln_target = NULL;
        unsigned int    save_inode;
@@ -735,6 +797,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
        int             read_cnt;
        int             hdlink;
        size_t          cur_dir_path_len;
+       int             i, num_dents;
 
        if (chdir(source_dir) < 0) {
                retval = errno;
@@ -744,24 +807,25 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
                return retval;
        }
 
-       if (!(dh = opendir("."))) {
+       num_dents = scandir(".", &dent, NULL, alphasort);
+
+       if (num_dents < 0) {
                retval = errno;
                com_err(__func__, retval,
-                       _("while opening directory \"%s\""), source_dir);
+                       _("while scanning directory \"%s\""), source_dir);
                return retval;
        }
 
-       while ((dent = readdir(dh))) {
-               if ((!strcmp(dent->d_name, ".")) ||
-                   (!strcmp(dent->d_name, "..")))
+       for (i = 0; i < num_dents; free(dent[i]), i++) {
+               name = dent[i]->d_name;
+               if ((!strcmp(name, ".")) || (!strcmp(name, "..")))
                        continue;
-               if (lstat(dent->d_name, &st)) {
+               if (lstat(name, &st)) {
                        retval = errno;
                        com_err(__func__, retval, _("while lstat \"%s\""),
-                               dent->d_name);
+                               name);
                        goto out;
                }
-               name = dent->d_name;
 
                /* Check for hardlinks */
                save_inode = 0;
@@ -953,7 +1017,8 @@ find_lnf:
        }
 
 out:
-       closedir(dh);
+       for (; i < num_dents; free(dent[i]), i++);
+       free(dent);
        return retval;
 }