Make cp and mv optionally preserve hard links.

git-svn-id: svn://busybox.net/trunk/busybox@3894 69ca8d6d-28ef-0310-b511-8ec308f3f277

3 files changed, 31 insertions, 2 deletions

diff --git a/libbb/Makefile b/libbb/Makefile
index ef8fef4b7..879be2452 100644
--- a/libbb/Makefile
+++ b/libbb/Makefile
@@ -45,7 +45,7 @@ obj-y += ask_confirmation.o chomp.o concat_path_file.o copy_file.o \
         xgetcwd.o xreadlink.o xregcomp.o interface.o remove_file.o last_char_is.o \
         copyfd.o vherror_msg.o herror_msg.o herror_msg_and_die.o xgethostbyname.o \
         dirname.o make_directory.o create_icmp_socket.o u_signal_names.o arith.o \
-        simplify_path.o inet_common.o $(LIBBB_MOBJS) $(LIBBB_AROBJS)
+        simplify_path.o inet_common.o inode_hash.o $(LIBBB_MOBJS) $(LIBBB_AROBJS)
 
 
 # Hand off to toplevel Rules.mak
diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index 29778f2a4..ea05c9b8e 100644
--- a/libbb/copy_file.c
+++ b/libbb/copy_file.c
@@ -30,7 +30,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "libbb.h"
+#include "busybox.h"
 
 int copy_file(const char *source, const char *dest, int flags)
 {
@@ -131,6 +131,19 @@ int copy_file(const char *source, const char *dest, int flags)
                 }
         } else if (S_ISREG(source_stat.st_mode)) {
                 FILE *sfp, *dfp=NULL;
+#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
+                char *link_name;
+
+                if (!(flags & FILEUTILS_DEREFERENCE) &&
+                                is_in_ino_dev_hashtable(&source_stat, &link_name)) {
+                        if (link(link_name, dest) < 0) {
+                                perror_msg("unable to link `%s'", dest);
+                                return -1;
+                        }
+
+                        return 0;
+                }
+#endif
 
                 if ((sfp = fopen(source, "r")) == NULL) {
                         perror_msg("unable to open `%s'", source);
@@ -212,12 +225,21 @@ int copy_file(const char *source, const char *dest, int flags)
                         if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
                                 perror_msg("unable to preserve ownership of `%s'", dest);
 #endif
+
+#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
+                add_to_ino_dev_hashtable(&source_stat, dest);
+#endif
+
                 return 0;
         } else {
                 error_msg("internal error: unrecognized file type");
                 return -1;
         }
 
+#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
+        add_to_ino_dev_hashtable(&source_stat, dest);
+#endif
+
 end:
 
         if (flags & FILEUTILS_PRESERVE_STATUS) {
diff --git a/libbb/inode_hash.c b/libbb/inode_hash.c
index 52c54cdc1..36484e6ae 100644
--- a/libbb/inode_hash.c
+++ b/libbb/inode_hash.c
@@ -29,6 +29,13 @@
 #define HASH_SIZE       311             /* Should be prime */
 #define hash_inode(i)   ((i) % HASH_SIZE)
 
+typedef struct ino_dev_hash_bucket_struct {
+  struct ino_dev_hash_bucket_struct *next;
+  ino_t ino;
+  dev_t dev;
+  char name[1];
+} ino_dev_hashtable_bucket_t;
+
 static ino_dev_hashtable_bucket_t *ino_dev_hashtable[HASH_SIZE];
 
 /*