make copy_file() a bit easier to understand, and smaller
authorDenis Vlasenko <vda.linux@googlemail.com>
Sat, 25 Aug 2007 21:14:55 +0000 (21:14 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Sat, 25 Aug 2007 21:14:55 +0000 (21:14 -0000)
function                                             old     new   delta
copy_file                                           1565    1447    -118
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-118)           Total: -118 bytes
   text    data     bss     dec     hex filename
 770938    1063   10788  782789   bf1c5 busybox_old
 770814    1063   10788  782665   bf149 busybox_unstripped

coreutils/cp.c
coreutils/libcoreutils/cp_mv_stat.c
libbb/copy_file.c
libbb/inode_hash.c

index 5b575819c2e1974ca7d272c873d265457100bde7..76dc566b3832b6e007d8fc2463b1b827b5ff39ca 100644 (file)
@@ -69,7 +69,6 @@ int cp_main(int argc, char **argv)
        if (argc == 2) {
                s_flags = cp_mv_stat2(*argv, &source_stat,
                                      (flags & FILEUTILS_DEREFERENCE) ? stat : lstat);
-               /* TODO: does coreutils cp exit? "cp BAD GOOD dir"... */
                if (s_flags < 0)
                        return EXIT_FAILURE;
                d_flags = cp_mv_stat(last, &dest_stat);
index 2e4f25e2184ddfb4fa11e08dacfbf41dcfc24f97..43583d48b094b36f7ab26413bb6305853c65a780 100644 (file)
@@ -31,7 +31,8 @@ int cp_mv_stat2(const char *fn, struct stat *fn_stat, stat_func sf)
                        return -1;
                }
                return 0;
-       } else if (S_ISDIR(fn_stat->st_mode)) {
+       }
+       if (S_ISDIR(fn_stat->st_mode)) {
                return 3;
        }
        return 1;
index 8a7db77e68c9acc57e65f053aaa3894c9e4f081d..a86e497f06203a52b7a0a34cebea6cd4f5f10f18 100644 (file)
@@ -60,9 +60,11 @@ static int ask_and_unlink(const char *dest, int flags)
  */
 int copy_file(const char *source, const char *dest, int flags)
 {
+       /* This is a recursive function, try to minimize stack usage */
+       /* NB: each struct stat is ~100 bytes */
        struct stat source_stat;
        struct stat dest_stat;
-       int status = 0;
+       signed char retval = 0;
        signed char dest_exists = 0;
        signed char ovr;
 
@@ -120,7 +122,7 @@ int copy_file(const char *source, const char *dest, int flags)
                        return -1;
                }
 
-               /* Create DEST */
+               /* Create DEST */
                if (dest_exists) {
                        if (!S_ISDIR(dest_stat.st_mode)) {
                                bb_error_msg("target '%s' is not a directory", dest);
@@ -133,22 +135,21 @@ int copy_file(const char *source, const char *dest, int flags)
                        mode = source_stat.st_mode;
                        if (!(flags & FILEUTILS_PRESERVE_STATUS))
                                mode = source_stat.st_mode & ~saved_umask;
+                       /* Allow owner to access new dir (at least for now) */
                        mode |= S_IRWXU;
-
                        if (mkdir(dest, mode) < 0) {
                                umask(saved_umask);
                                bb_perror_msg("cannot create directory '%s'", dest);
                                return -1;
                        }
-
                        umask(saved_umask);
                }
 
-               /* Recursively copy files in SOURCE */
+               /* Recursively copy files in SOURCE */
                dp = opendir(source);
                if (dp == NULL) {
-                       status = -1;
-                       goto preserve_status;
+                       retval = -1;
+                       goto preserve_mode_ugid_time;
                }
 
                while ((d = readdir(dp)) != NULL) {
@@ -159,7 +160,7 @@ int copy_file(const char *source, const char *dest, int flags)
                                continue;
                        new_dest = concat_path_file(dest, d->d_name);
                        if (copy_file(new_source, new_dest, flags) < 0)
-                               status = -1;
+                               retval = -1;
                        free(new_source);
                        free(new_dest);
                }
@@ -169,10 +170,12 @@ int copy_file(const char *source, const char *dest, int flags)
                 && chmod(dest, source_stat.st_mode & ~saved_umask) < 0
                ) {
                        bb_perror_msg("cannot change permissions of '%s'", dest);
-                       status = -1;
+                       retval = -1;
                }
+               goto preserve_mode_ugid_time;
+       }
 
-       } else if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
+       if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
                int (*lf)(const char *oldpath, const char *newpath);
  make_links:
                // Hmm... maybe
@@ -188,39 +191,40 @@ int copy_file(const char *source, const char *dest, int flags)
                                return -1;
                        }
                }
+               /* _Not_ jumping to preserve_mode_ugid_time:
+                * hard/softlinks don't have those */
                return 0;
+       }
 
-       } else if (S_ISREG(source_stat.st_mode)
+       if (S_ISREG(source_stat.st_mode)
         /* Huh? DEREF uses stat, which never returns links! */
         /* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */
        ) {
                int src_fd;
                int dst_fd;
-               if (ENABLE_FEATURE_PRESERVE_HARDLINKS) {
+
+               if (ENABLE_FEATURE_PRESERVE_HARDLINKS && !FLAGS_DEREF) {
                        char *link_target;
 
-                       if (!FLAGS_DEREF) {
-                               link_target = is_in_ino_dev_hashtable(&source_stat);
-                               if (link_target) {
+                       link_target = is_in_ino_dev_hashtable(&source_stat);
+                       if (link_target) {
+                               if (link(link_target, dest) < 0) {
+                                       ovr = ask_and_unlink(dest, flags);
+                                       if (ovr <= 0)
+                                               return ovr;
                                        if (link(link_target, dest) < 0) {
-                                               ovr = ask_and_unlink(dest, flags);
-                                               if (ovr <= 0)
-                                                       return ovr;
-                                               if (link(link_target, dest) < 0) {
-                                                       bb_perror_msg("cannot create link '%s'", dest);
-                                                       return -1;
-                                               }
+                                               bb_perror_msg("cannot create link '%s'", dest);
+                                               return -1;
                                        }
-                                       return 0;
                                }
+                               return 0;
                        }
                        add_to_ino_dev_hashtable(&source_stat, dest);
                }
 
                src_fd = open_or_warn(source, O_RDONLY);
-               if (src_fd < 0) {
+               if (src_fd < 0)
                        return -1;
-               }
 
 #if DO_POSIX_CP  /* POSIX way (a security problem versus symlink attacks!): */
                dst_fd = open(dest, (flags & FILEUTILS_INTERACTIVE)
@@ -264,61 +268,56 @@ int copy_file(const char *source, const char *dest, int flags)
                }
 #endif
                if (bb_copyfd_eof(src_fd, dst_fd) == -1)
-                       status = -1;
+                       retval = -1;
                if (close(dst_fd) < 0) {
                        bb_perror_msg("cannot close '%s'", dest);
-                       status = -1;
+                       retval = -1;
                }
                if (close(src_fd) < 0) {
                        bb_perror_msg("cannot close '%s'", source);
-                       status = -1;
+                       retval = -1;
                }
+               goto preserve_mode_ugid_time;
+       }
 
-       } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode)
-        || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode)
-        || S_ISLNK(source_stat.st_mode)
-       ) {
-               // We are lazy here, a bit lax with races...
-               if (dest_exists) {
-                       errno = EEXIST;
-                       ovr = ask_and_unlink(dest, flags);
-                       if (ovr <= 0)
-                               return ovr;
-               }
-               if (S_ISFIFO(source_stat.st_mode)) {
-                       if (mkfifo(dest, source_stat.st_mode) < 0) {
-                               bb_perror_msg("cannot create fifo '%s'", dest);
-                               return -1;
-                       }
-               } else if (S_ISLNK(source_stat.st_mode)) {
-                       char *lpath;
+       /* Source is a symlink or a special file */
+       /* We are lazy here, a bit lax with races... */
+       if (dest_exists) {
+               errno = EEXIST;
+               ovr = ask_and_unlink(dest, flags);
+               if (ovr <= 0)
+                       return ovr;
+       }
+       if (S_ISLNK(source_stat.st_mode)) {
+               char *lpath;
 
-                       lpath = xmalloc_readlink_or_warn(source);
-                       if (lpath && symlink(lpath, dest) < 0) {
-                               bb_perror_msg("cannot create symlink '%s'", dest);
-                               free(lpath);
-                               return -1;
-                       }
+               lpath = xmalloc_readlink_or_warn(source);
+               if (lpath && symlink(lpath, dest) < 0) {
+                       bb_perror_msg("cannot create symlink '%s'", dest);
                        free(lpath);
-
-                       if (flags & FILEUTILS_PRESERVE_STATUS)
-                               if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
-                                       bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
-
-                       return 0;
-
-               } else {
-                       if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
-                               bb_perror_msg("cannot create '%s'", dest);
-                               return -1;
-                       }
+                       return -1;
+               }
+               free(lpath);
+               if (flags & FILEUTILS_PRESERVE_STATUS)
+                       if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
+                               bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
+               /* _Not_ jumping to preserve_mode_ugid_time:
+                * symlinks don't have those */
+               return 0;
+       }
+       if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode)
+        || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode)
+       ) {
+               if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
+                       bb_perror_msg("cannot create '%s'", dest);
+                       return -1;
                }
        } else {
-               bb_error_msg("internal error: unrecognized file type");
+               bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode);
                return -1;
        }
 
- preserve_status:
+ preserve_mode_ugid_time:
 
        if (flags & FILEUTILS_PRESERVE_STATUS
        /* Cannot happen: */
@@ -338,5 +337,5 @@ int copy_file(const char *source, const char *dest, int flags)
                        bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
        }
 
-       return status;
+       return retval;
 }
index 69e39af63632cc935426236668bc39f3b738e09b..9cca74bcb4ab9eadfdede8a6e50944042f612a39 100644 (file)
@@ -84,6 +84,4 @@ void reset_ino_dev_hashtable(void)
        free(ino_dev_hashtable);
        ino_dev_hashtable = NULL;
 }
-#else
-void reset_ino_dev_hashtable(void);
 #endif