From 37ddfb0b7eb41cc3f58bce686d389b1e965e9ccf Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Mon, 23 Aug 2010 19:12:25 -0700 Subject: [PATCH] tar: handle files that occur multiple times but have link count 1 This patch was inspired by the following patch that addressed a similar problem in GNU coreutils du: http://git.savannah.gnu.org/gitweb/?p=coreutils.git;h=efe53cc72b599979ea292754ecfe8abf7c839d22 * src/common.h (name_count): New decl. * src/create.c (trivial_link_count): New static var. (create_archive): Initialize it. (dump_hard_link, file_count_links): Use it, so that files with link count 1 are handled correctly when they are found multiple times. * src/names.c (allocated_entries): Renamed from allocated_names, since the identifier's name was misleading. All uses changed. (entries): Renamed from names. All uses changed. (scanned): Renamed from name_index. All uses changed. (name_count): New var. (name_add_name): Increment it. * tests/link04.at: New file. * tests/testsuite.at: Add it. * tests/Makefile.am (TESTSUITE_AT): Likewise. --- src/common.h | 1 + src/create.c | 13 +++++++++-- src/names.c | 26 +++++++++++---------- tests/Makefile.am | 1 + tests/link04.at | 58 ++++++++++++++++++++++++++++++++++++++++++++++ tests/testsuite.at | 1 + 6 files changed, 86 insertions(+), 14 deletions(-) create mode 100644 tests/link04.at diff --git a/src/common.h b/src/common.h index 24227f4..9d0b779 100644 --- a/src/common.h +++ b/src/common.h @@ -636,6 +636,7 @@ int set_file_atime (int fd, char const *file, /* Module names.c. */ +extern size_t name_count; extern struct name *gnu_list_name; void gid_to_gname (gid_t gid, char **gname); diff --git a/src/create.c b/src/create.c index ce7d966..0a6bacf 100644 --- a/src/create.c +++ b/src/create.c @@ -1265,6 +1265,12 @@ dump_dir (int fd, struct tar_stat_info *st, bool top_level, return true; } + +/* Number of links a file can have without having to be entered into + the link table. Typically this is 1, but in trickier circumstances + it is 0. */ +static nlink_t trivial_link_count; + /* Main functions of this module. */ @@ -1273,6 +1279,8 @@ create_archive (void) { struct name const *p; + trivial_link_count = name_count <= 1 && ! dereference_option; + open_archive (ACCESS_WRITE); buffer_write_global_xheader (); @@ -1380,7 +1388,8 @@ static Hash_table *link_table; static bool dump_hard_link (struct tar_stat_info *st) { - if (link_table && (st->stat.st_nlink > 1 || remove_files_option)) + if (link_table + && (trivial_link_count < st->stat.st_nlink || remove_files_option)) { struct link lp; struct link *duplicate; @@ -1427,7 +1436,7 @@ file_count_links (struct tar_stat_info *st) { if (hard_dereference_option) return; - if (st->stat.st_nlink > 1) + if (trivial_link_count < st->stat.st_nlink) { struct link *duplicate; char *linkname = NULL; diff --git a/src/names.c b/src/names.c index f1e5ab1..d2f14b0 100644 --- a/src/names.c +++ b/src/names.c @@ -226,19 +226,20 @@ struct name_elt /* A name_array element. */ }; static struct name_elt *name_array; /* store an array of names */ -static size_t allocated_names; /* how big is the array? */ -static size_t names; /* how many entries does it have? */ -static size_t name_index; /* how many of the entries have we scanned? */ +static size_t allocated_entries; /* how big is the array? */ +static size_t entries; /* how many entries does it have? */ +static size_t scanned; /* how many of the entries have we scanned? */ +size_t name_count; /* how many of the entries are names? */ /* Check the size of name_array, reallocating it as necessary. */ static void check_name_alloc (void) { - if (names == allocated_names) + if (entries == allocated_entries) { - if (allocated_names == 0) - allocated_names = 10; /* Set initial allocation */ - name_array = x2nrealloc (name_array, &allocated_names, + if (allocated_entries == 0) + allocated_entries = 10; /* Set initial allocation */ + name_array = x2nrealloc (name_array, &allocated_entries, sizeof (name_array[0])); } } @@ -251,17 +252,18 @@ name_add_name (const char *name, int matching_flags) struct name_elt *ep; check_name_alloc (); - ep = &name_array[names++]; + ep = &name_array[entries++]; if (prev_flags != matching_flags) { ep->type = NELT_FMASK; ep->v.matching_flags = matching_flags; prev_flags = matching_flags; check_name_alloc (); - ep = &name_array[names++]; + ep = &name_array[entries++]; } ep->type = NELT_NAME; ep->v.name = name; + name_count++; } /* Add to name_array a chdir request for the directory NAME */ @@ -270,7 +272,7 @@ name_add_dir (const char *name) { struct name_elt *ep; check_name_alloc (); - ep = &name_array[names++]; + ep = &name_array[entries++]; ep->type = NELT_CHDIR; ep->v.name = name; } @@ -314,12 +316,12 @@ name_next_elt (int change_dirs) const char *source; char *cursor; - while (name_index != names) + while (scanned != entries) { struct name_elt *ep; size_t source_len; - ep = &name_array[name_index++]; + ep = &name_array[scanned++]; if (ep->type == NELT_FMASK) { matching_flags = ep->v.matching_flags; diff --git a/tests/Makefile.am b/tests/Makefile.am index 01b0bae..e2e338a 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -97,6 +97,7 @@ TESTSUITE_AT = \ link01.at\ link02.at\ link03.at\ + link04.at\ listed01.at\ listed02.at\ listed03.at\ diff --git a/tests/link04.at b/tests/link04.at new file mode 100644 index 0000000..a950476 --- /dev/null +++ b/tests/link04.at @@ -0,0 +1,58 @@ +# Process this file with autom4te to create testsuite. -*- Autotest -*- + +# Test suite for GNU tar. +# Copyright (C) 2010 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +# 02110-1301, USA. + +# written by Paul Eggert + +AT_SETUP([link count is 1 but multiple occurrences]) +AT_KEYWORDS([hardlinks link04]) + +AT_TAR_CHECK([ +mkdir dir +echo TEST > dir/file +ln -s file dir/symlink || AT_SKIP_TEST + +tar cf archive dir dir +tar tvf archive | sed ' + s,.*[[0-9]] dir/,dir/, +' | sort + +echo == + +tar chf archive dir +tar tvf archive | sed ' + s,.*[[0-9]] dir/,dir/, + s,file,FOO,g + s,symlink,FOO,g +' | sort +], +[0], +[dir/ +dir/ +dir/file +dir/file link to dir/file +dir/symlink -> file +dir/symlink link to dir/symlink +== +dir/ +dir/FOO +dir/FOO link to dir/FOO +]) + +AT_CLEANUP diff --git a/tests/testsuite.at b/tests/testsuite.at index 1048a0a..d8b9b09 100644 --- a/tests/testsuite.at +++ b/tests/testsuite.at @@ -184,6 +184,7 @@ m4_include([ignfail.at]) m4_include([link01.at]) m4_include([link02.at]) m4_include([link03.at]) +m4_include([link04.at]) m4_include([longv7.at]) m4_include([long01.at]) -- 2.45.2