From f167e4503d08561054e75deb2ff123be2b30afa5 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 22 Oct 2015 13:30:34 +0200 Subject: tar: shrink hardlink name handling code function old new delta data_extract_all 1069 1040 -29 Signed-off-by: Denys Vlasenko --- archival/libarchive/data_extract_all.c | 43 ++++++++++++++-------------------- 1 file changed, 17 insertions(+), 26 deletions(-) (limited to 'archival') diff --git a/archival/libarchive/data_extract_all.c b/archival/libarchive/data_extract_all.c index bd51d2ad3..cf821c9de 100644 --- a/archival/libarchive/data_extract_all.c +++ b/archival/libarchive/data_extract_all.c @@ -12,12 +12,11 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) file_header_t *file_header = archive_handle->file_header; int dst_fd; int res; + char *hard_link; #if ENABLE_FEATURE_TAR_LONG_OPTIONS char *dst_name; - char *dst_link; #else # define dst_name (file_header->name) -# define dst_link (file_header->link_target) #endif #if ENABLE_FEATURE_TAR_SELINUX @@ -31,9 +30,14 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) } #endif + /* Hard links are encoded as regular files of size 0 + * with a nonempty link field */ + hard_link = NULL; + if (S_ISREG(file_header->mode) && file_header->size == 0) + hard_link = file_header->link_target; + #if ENABLE_FEATURE_TAR_LONG_OPTIONS dst_name = file_header->name; - dst_link = file_header->link_target; if (archive_handle->tar__strip_components) { unsigned n = archive_handle->tar__strip_components; do { @@ -47,21 +51,18 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) * Link target is shortened only for hardlinks: * softlinks restored unchanged. */ - if (S_ISREG(file_header->mode) - && file_header->size == 0 - && dst_link - ) { + if (hard_link) { // GNU tar 1.26 does not check that we reached end of link name: // if "dir/hardlink" is hardlinked to "file", // tar xvf a.tar --strip-components=1 says: // tar: hardlink: Cannot hard link to '': No such file or directory // and continues processing. We silently skip such entries. - dst_link = strchr(dst_link, '/'); - if (!dst_link || dst_link[1] == '\0') { + hard_link = strchr(hard_link, '/'); + if (!hard_link || hard_link[1] == '\0') { data_skip(archive_handle); return; } - dst_link++; + hard_link++; } } while (--n != 0); } @@ -79,12 +80,7 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) if (archive_handle->ah_flags & ARCHIVE_UNLINK_OLD) { /* Remove the entry if it exists */ if (!S_ISDIR(file_header->mode)) { - /* Is it hardlink? - * We encode hard links as regular files of size 0 with a symlink */ - if (S_ISREG(file_header->mode) - && file_header->size == 0 - && dst_link - ) { + if (hard_link) { /* Ugly special case: * tar cf t.tar hardlink1 hardlink2 hardlink1 * results in this tarball structure: @@ -92,7 +88,7 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) * hardlink2 -> hardlink1 * hardlink1 -> hardlink1 <== !!! */ - if (strcmp(dst_link, dst_name) == 0) + if (strcmp(hard_link, dst_name) == 0) goto ret; } /* Proceed with deleting */ @@ -128,19 +124,14 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) } } - /* Handle hard links separately - * We encode hard links as regular files of size 0 with a symlink */ - if (S_ISREG(file_header->mode) - && file_header->size == 0 - && dst_link - ) { - /* Hard link */ - res = link(dst_link, dst_name); + /* Handle hard links separately */ + if (hard_link) { + res = link(hard_link, dst_name); if (res != 0 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) { bb_perror_msg("can't create %slink " "from %s to %s", "hard", dst_name, - dst_link); + hard_link); } /* Hardlinks have no separate mode/ownership, skip chown/chmod */ goto ret; -- cgit v1.2.3