git/bundle.c
Michael Haggerty e54c347c1c create_bundle(): duplicate file descriptor to avoid closing it twice
write_pack_data() passes bundle_fd to start_command() to be used as
the stdout of pack-objects. But start_command() closes its stdout if
it is > 1. This is a problem if bundle_fd is the fd of a lock_file,
because commit_lock_file() will also try to close the fd.

So the old code suppressed commit_lock_file()'s usual behavior of
closing the file descriptor by setting the lock_file object's fd field
to -1.

But this is not really kosher. Code here shouldn't be mutating fields
within the lock_file object.

Instead, duplicate the file descriptor before passing it to
write_pack_data(). Then that function can close its copy without
closing the copy held in the lock_file object.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 12:57:14 -07:00

483 lines
12 KiB
C

#include "cache.h"
#include "lockfile.h"
#include "bundle.h"
#include "object.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "run-command.h"
#include "refs.h"
#include "argv-array.h"
static const char bundle_signature[] = "# v2 git bundle\n";
static void add_to_ref_list(const unsigned char *sha1, const char *name,
struct ref_list *list)
{
ALLOC_GROW(list->list, list->nr + 1, list->alloc);
hashcpy(list->list[list->nr].sha1, sha1);
list->list[list->nr].name = xstrdup(name);
list->nr++;
}
static int parse_bundle_header(int fd, struct bundle_header *header,
const char *report_path)
{
struct strbuf buf = STRBUF_INIT;
int status = 0;
/* The bundle header begins with the signature */
if (strbuf_getwholeline_fd(&buf, fd, '\n') ||
strcmp(buf.buf, bundle_signature)) {
if (report_path)
error(_("'%s' does not look like a v2 bundle file"),
report_path);
status = -1;
goto abort;
}
/* The bundle header ends with an empty line */
while (!strbuf_getwholeline_fd(&buf, fd, '\n') &&
buf.len && buf.buf[0] != '\n') {
unsigned char sha1[20];
int is_prereq = 0;
if (*buf.buf == '-') {
is_prereq = 1;
strbuf_remove(&buf, 0, 1);
}
strbuf_rtrim(&buf);
/*
* Tip lines have object name, SP, and refname.
* Prerequisites have object name that is optionally
* followed by SP and subject line.
*/
if (get_sha1_hex(buf.buf, sha1) ||
(buf.len > 40 && !isspace(buf.buf[40])) ||
(!is_prereq && buf.len <= 40)) {
if (report_path)
error(_("unrecognized header: %s%s (%d)"),
(is_prereq ? "-" : ""), buf.buf, (int)buf.len);
status = -1;
break;
} else {
if (is_prereq)
add_to_ref_list(sha1, "", &header->prerequisites);
else
add_to_ref_list(sha1, buf.buf + 41, &header->references);
}
}
abort:
if (status) {
close(fd);
fd = -1;
}
strbuf_release(&buf);
return fd;
}
int read_bundle_header(const char *path, struct bundle_header *header)
{
int fd = open(path, O_RDONLY);
if (fd < 0)
return error(_("could not open '%s'"), path);
return parse_bundle_header(fd, header, path);
}
int is_bundle(const char *path, int quiet)
{
struct bundle_header header;
int fd = open(path, O_RDONLY);
if (fd < 0)
return 0;
memset(&header, 0, sizeof(header));
fd = parse_bundle_header(fd, &header, quiet ? NULL : path);
if (fd >= 0)
close(fd);
return (fd >= 0);
}
static int list_refs(struct ref_list *r, int argc, const char **argv)
{
int i;
for (i = 0; i < r->nr; i++) {
if (argc > 1) {
int j;
for (j = 1; j < argc; j++)
if (!strcmp(r->list[i].name, argv[j]))
break;
if (j == argc)
continue;
}
printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
r->list[i].name);
}
return 0;
}
/* Remember to update object flag allocation in object.h */
#define PREREQ_MARK (1u<<16)
int verify_bundle(struct bundle_header *header, int verbose)
{
/*
* Do fast check, then if any prereqs are missing then go line by line
* to be verbose about the errors
*/
struct ref_list *p = &header->prerequisites;
struct rev_info revs;
const char *argv[] = {NULL, "--all", NULL};
struct object_array refs;
struct commit *commit;
int i, ret = 0, req_nr;
const char *message = _("Repository lacks these prerequisite commits:");
init_revisions(&revs, NULL);
for (i = 0; i < p->nr; i++) {
struct ref_list_entry *e = p->list + i;
struct object *o = parse_object(e->sha1);
if (o) {
o->flags |= PREREQ_MARK;
add_pending_object(&revs, o, e->name);
continue;
}
if (++ret == 1)
error("%s", message);
error("%s %s", sha1_to_hex(e->sha1), e->name);
}
if (revs.pending.nr != p->nr)
return ret;
req_nr = revs.pending.nr;
setup_revisions(2, argv, &revs, NULL);
refs = revs.pending;
revs.leak_pending = 1;
if (prepare_revision_walk(&revs))
die(_("revision walk setup failed"));
i = req_nr;
while (i && (commit = get_revision(&revs)))
if (commit->object.flags & PREREQ_MARK)
i--;
for (i = 0; i < req_nr; i++)
if (!(refs.objects[i].item->flags & SHOWN)) {
if (++ret == 1)
error("%s", message);
error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
refs.objects[i].name);
}
clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
free(refs.objects);
if (verbose) {
struct ref_list *r;
r = &header->references;
printf_ln(Q_("The bundle contains this ref:",
"The bundle contains these %d refs:",
r->nr),
r->nr);
list_refs(r, 0, NULL);
r = &header->prerequisites;
if (!r->nr) {
printf_ln(_("The bundle records a complete history."));
} else {
printf_ln(Q_("The bundle requires this ref:",
"The bundle requires these %d refs:",
r->nr),
r->nr);
list_refs(r, 0, NULL);
}
}
return ret;
}
int list_bundle_refs(struct bundle_header *header, int argc, const char **argv)
{
return list_refs(&header->references, argc, argv);
}
static int is_tag_in_date_range(struct object *tag, struct rev_info *revs)
{
unsigned long size;
enum object_type type;
char *buf = NULL, *line, *lineend;
unsigned long date;
int result = 1;
if (revs->max_age == -1 && revs->min_age == -1)
goto out;
buf = read_sha1_file(tag->sha1, &type, &size);
if (!buf)
goto out;
line = memmem(buf, size, "\ntagger ", 8);
if (!line++)
goto out;
lineend = memchr(line, '\n', buf + size - line);
line = memchr(line, '>', lineend ? lineend - line : buf + size - line);
if (!line++)
goto out;
date = strtoul(line, NULL, 10);
result = (revs->max_age == -1 || revs->max_age < date) &&
(revs->min_age == -1 || revs->min_age > date);
out:
free(buf);
return result;
}
/* Write the pack data to bundle_fd, then close it if it is > 1. */
static int write_pack_data(int bundle_fd, struct rev_info *revs)
{
struct child_process pack_objects = CHILD_PROCESS_INIT;
int i;
argv_array_pushl(&pack_objects.args,
"pack-objects", "--all-progress-implied",
"--stdout", "--thin", "--delta-base-offset",
NULL);
pack_objects.in = -1;
pack_objects.out = bundle_fd;
pack_objects.git_cmd = 1;
if (start_command(&pack_objects))
return error(_("Could not spawn pack-objects"));
for (i = 0; i < revs->pending.nr; i++) {
struct object *object = revs->pending.objects[i].item;
if (object->flags & UNINTERESTING)
write_or_die(pack_objects.in, "^", 1);
write_or_die(pack_objects.in, sha1_to_hex(object->sha1), 40);
write_or_die(pack_objects.in, "\n", 1);
}
close(pack_objects.in);
if (finish_command(&pack_objects))
return error(_("pack-objects died"));
return 0;
}
static int compute_and_write_prerequisites(int bundle_fd,
struct rev_info *revs,
int argc, const char **argv)
{
struct child_process rls = CHILD_PROCESS_INIT;
struct strbuf buf = STRBUF_INIT;
FILE *rls_fout;
int i;
argv_array_pushl(&rls.args,
"rev-list", "--boundary", "--pretty=oneline",
NULL);
for (i = 1; i < argc; i++)
argv_array_push(&rls.args, argv[i]);
rls.out = -1;
rls.git_cmd = 1;
if (start_command(&rls))
return -1;
rls_fout = xfdopen(rls.out, "r");
while (strbuf_getwholeline(&buf, rls_fout, '\n') != EOF) {
unsigned char sha1[20];
if (buf.len > 0 && buf.buf[0] == '-') {
write_or_die(bundle_fd, buf.buf, buf.len);
if (!get_sha1_hex(buf.buf + 1, sha1)) {
struct object *object = parse_object_or_die(sha1, buf.buf);
object->flags |= UNINTERESTING;
add_pending_object(revs, object, buf.buf);
}
} else if (!get_sha1_hex(buf.buf, sha1)) {
struct object *object = parse_object_or_die(sha1, buf.buf);
object->flags |= SHOWN;
}
}
strbuf_release(&buf);
fclose(rls_fout);
if (finish_command(&rls))
return error(_("rev-list died"));
return 0;
}
/*
* Write out bundle refs based on the tips already
* parsed into revs.pending. As a side effect, may
* manipulate revs.pending to include additional
* necessary objects (like tags).
*
* Returns the number of refs written, or negative
* on error.
*/
static int write_bundle_refs(int bundle_fd, struct rev_info *revs)
{
int i;
int ref_count = 0;
for (i = 0; i < revs->pending.nr; i++) {
struct object_array_entry *e = revs->pending.objects + i;
unsigned char sha1[20];
char *ref;
const char *display_ref;
int flag;
if (e->item->flags & UNINTERESTING)
continue;
if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
goto skip_write_ref;
if (read_ref_full(e->name, RESOLVE_REF_READING, sha1, &flag))
flag = 0;
display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
if (e->item->type == OBJ_TAG &&
!is_tag_in_date_range(e->item, revs)) {
e->item->flags |= UNINTERESTING;
goto skip_write_ref;
}
/*
* Make sure the refs we wrote out is correct; --max-count and
* other limiting options could have prevented all the tips
* from getting output.
*
* Non commit objects such as tags and blobs do not have
* this issue as they are not affected by those extra
* constraints.
*/
if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
warning(_("ref '%s' is excluded by the rev-list options"),
e->name);
goto skip_write_ref;
}
/*
* If you run "git bundle create bndl v1.0..v2.0", the
* name of the positive ref is "v2.0" but that is the
* commit that is referenced by the tag, and not the tag
* itself.
*/
if (hashcmp(sha1, e->item->sha1)) {
/*
* Is this the positive end of a range expressed
* in terms of a tag (e.g. v2.0 from the range
* "v1.0..v2.0")?
*/
struct commit *one = lookup_commit_reference(sha1);
struct object *obj;
if (e->item == &(one->object)) {
/*
* Need to include e->name as an
* independent ref to the pack-objects
* input, so that the tag is included
* in the output; otherwise we would
* end up triggering "empty bundle"
* error.
*/
obj = parse_object_or_die(sha1, e->name);
obj->flags |= SHOWN;
add_pending_object(revs, obj, e->name);
}
goto skip_write_ref;
}
ref_count++;
write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
write_or_die(bundle_fd, " ", 1);
write_or_die(bundle_fd, display_ref, strlen(display_ref));
write_or_die(bundle_fd, "\n", 1);
skip_write_ref:
free(ref);
}
/* end header */
write_or_die(bundle_fd, "\n", 1);
return ref_count;
}
int create_bundle(struct bundle_header *header, const char *path,
int argc, const char **argv)
{
static struct lock_file lock;
int bundle_fd = -1;
int bundle_to_stdout;
int ref_count = 0;
struct rev_info revs;
bundle_to_stdout = !strcmp(path, "-");
if (bundle_to_stdout)
bundle_fd = 1;
else {
bundle_fd = hold_lock_file_for_update(&lock, path,
LOCK_DIE_ON_ERROR);
/*
* write_pack_data() will close the fd passed to it,
* but commit_lock_file() will also try to close the
* lockfile's fd. So make a copy of the file
* descriptor to avoid trying to close it twice.
*/
bundle_fd = dup(bundle_fd);
if (bundle_fd < 0)
die_errno("unable to dup file descriptor");
}
/* write signature */
write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
/* init revs to list objects for pack-objects later */
save_commit_buffer = 0;
init_revisions(&revs, NULL);
/* write prerequisites */
if (compute_and_write_prerequisites(bundle_fd, &revs, argc, argv))
return -1;
argc = setup_revisions(argc, argv, &revs, NULL);
if (argc > 1)
return error(_("unrecognized argument: %s"), argv[1]);
object_array_remove_duplicates(&revs.pending);
ref_count = write_bundle_refs(bundle_fd, &revs);
if (!ref_count)
die(_("Refusing to create empty bundle."));
else if (ref_count < 0)
return -1;
/* write pack */
if (write_pack_data(bundle_fd, &revs))
return -1;
if (!bundle_to_stdout) {
if (commit_lock_file(&lock))
die_errno(_("cannot create '%s'"), path);
}
return 0;
}
int unbundle(struct bundle_header *header, int bundle_fd, int flags)
{
const char *argv_index_pack[] = {"index-pack",
"--fix-thin", "--stdin", NULL, NULL};
struct child_process ip = CHILD_PROCESS_INIT;
if (flags & BUNDLE_VERBOSE)
argv_index_pack[3] = "-v";
if (verify_bundle(header, 0))
return -1;
ip.argv = argv_index_pack;
ip.in = bundle_fd;
ip.no_stdout = 1;
ip.git_cmd = 1;
if (run_command(&ip))
return error(_("index-pack died"));
return 0;
}