git/server-info.c
René Scharfe fa1912c89a server-info: avoid calling fclose(3) twice in update_info_file()
If an error occurs when or after closing the stream we call fclose(3)
again in the error handler.  The second call can exhibit undefined
behavior, so make sure to call fclose(3) at most once.  Also avoid
calling close(2) after fd has been successfully associated with the
stream, as fclose(3) has become responsible for doing that beyond
this point.

Found with Cppcheck.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-17 17:37:28 -07:00

288 lines
5.7 KiB
C

#include "cache.h"
#include "refs.h"
#include "object.h"
#include "commit.h"
#include "tag.h"
/*
* Create the file "path" by writing to a temporary file and renaming
* it into place. The contents of the file come from "generate", which
* should return non-zero if it encounters an error.
*/
static int update_info_file(char *path, int (*generate)(FILE *))
{
char *tmp = mkpathdup("%s_XXXXXX", path);
int ret = -1;
int fd = -1;
FILE *fp = NULL, *to_close;
safe_create_leading_directories(path);
fd = git_mkstemp_mode(tmp, 0666);
if (fd < 0)
goto out;
to_close = fp = fdopen(fd, "w");
if (!fp)
goto out;
fd = -1;
ret = generate(fp);
if (ret)
goto out;
fp = NULL;
if (fclose(to_close))
goto out;
if (adjust_shared_perm(tmp) < 0)
goto out;
if (rename(tmp, path) < 0)
goto out;
ret = 0;
out:
if (ret) {
error_errno("unable to update %s", path);
if (fp)
fclose(fp);
else if (fd >= 0)
close(fd);
unlink(tmp);
}
free(tmp);
return ret;
}
static int add_info_ref(const char *path, const struct object_id *oid,
int flag, void *cb_data)
{
FILE *fp = cb_data;
struct object *o = parse_object(oid->hash);
if (!o)
return -1;
if (fprintf(fp, "%s %s\n", oid_to_hex(oid), path) < 0)
return -1;
if (o->type == OBJ_TAG) {
o = deref_tag(o, path, 0);
if (o)
if (fprintf(fp, "%s %s^{}\n",
oid_to_hex(&o->oid), path) < 0)
return -1;
}
return 0;
}
static int generate_info_refs(FILE *fp)
{
return for_each_ref(add_info_ref, fp);
}
static int update_info_refs(int force)
{
char *path = git_pathdup("info/refs");
int ret = update_info_file(path, generate_info_refs);
free(path);
return ret;
}
/* packs */
static struct pack_info {
struct packed_git *p;
int old_num;
int new_num;
int nr_alloc;
int nr_heads;
unsigned char (*head)[20];
} **info;
static int num_pack;
static const char *objdir;
static int objdirlen;
static struct pack_info *find_pack_by_name(const char *name)
{
int i;
for (i = 0; i < num_pack; i++) {
struct packed_git *p = info[i]->p;
/* skip "/pack/" after ".git/objects" */
if (!strcmp(p->pack_name + objdirlen + 6, name))
return info[i];
}
return NULL;
}
/* Returns non-zero when we detect that the info in the
* old file is useless.
*/
static int parse_pack_def(const char *line, int old_cnt)
{
struct pack_info *i = find_pack_by_name(line + 2);
if (i) {
i->old_num = old_cnt;
return 0;
}
else {
/* The file describes a pack that is no longer here */
return 1;
}
}
/* Returns non-zero when we detect that the info in the
* old file is useless.
*/
static int read_pack_info_file(const char *infofile)
{
FILE *fp;
char line[1000];
int old_cnt = 0;
fp = fopen(infofile, "r");
if (!fp)
return 1; /* nonexistent is not an error. */
while (fgets(line, sizeof(line), fp)) {
int len = strlen(line);
if (len && line[len-1] == '\n')
line[--len] = 0;
if (!len)
continue;
switch (line[0]) {
case 'P': /* P name */
if (parse_pack_def(line, old_cnt++))
goto out_stale;
break;
case 'D': /* we used to emit D but that was misguided. */
case 'T': /* we used to emit T but nobody uses it. */
goto out_stale;
default:
error("unrecognized: %s", line);
break;
}
}
fclose(fp);
return 0;
out_stale:
fclose(fp);
return 1;
}
static int compare_info(const void *a_, const void *b_)
{
struct pack_info *const *a = a_;
struct pack_info *const *b = b_;
if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
/* Keep the order in the original */
return (*a)->old_num - (*b)->old_num;
else if (0 <= (*a)->old_num)
/* Only A existed in the original so B is obviously newer */
return -1;
else if (0 <= (*b)->old_num)
/* The other way around. */
return 1;
/* then it does not matter but at least keep the comparison stable */
if ((*a)->p == (*b)->p)
return 0;
else if ((*a)->p < (*b)->p)
return -1;
else
return 1;
}
static void init_pack_info(const char *infofile, int force)
{
struct packed_git *p;
int stale;
int i = 0;
objdir = get_object_directory();
objdirlen = strlen(objdir);
prepare_packed_git();
for (p = packed_git; p; p = p->next) {
/* we ignore things on alternate path since they are
* not available to the pullers in general.
*/
if (!p->pack_local)
continue;
i++;
}
num_pack = i;
info = xcalloc(num_pack, sizeof(struct pack_info *));
for (i = 0, p = packed_git; p; p = p->next) {
if (!p->pack_local)
continue;
info[i] = xcalloc(1, sizeof(struct pack_info));
info[i]->p = p;
info[i]->old_num = -1;
i++;
}
if (infofile && !force)
stale = read_pack_info_file(infofile);
else
stale = 1;
for (i = 0; i < num_pack; i++) {
if (stale) {
info[i]->old_num = -1;
info[i]->nr_heads = 0;
}
}
/* renumber them */
QSORT(info, num_pack, compare_info);
for (i = 0; i < num_pack; i++)
info[i]->new_num = i;
}
static void free_pack_info(void)
{
int i;
for (i = 0; i < num_pack; i++)
free(info[i]);
free(info);
}
static int write_pack_info_file(FILE *fp)
{
int i;
for (i = 0; i < num_pack; i++) {
if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
return -1;
}
if (fputc('\n', fp) == EOF)
return -1;
return 0;
}
static int update_info_packs(int force)
{
char *infofile = mkpathdup("%s/info/packs", get_object_directory());
int ret;
init_pack_info(infofile, force);
ret = update_info_file(infofile, write_pack_info_file);
free_pack_info();
free(infofile);
return ret;
}
/* public */
int update_server_info(int force)
{
/* We would add more dumb-server support files later,
* including index of available pack files and their
* intended audiences.
*/
int errs = 0;
errs = errs | update_info_refs(force);
errs = errs | update_info_packs(force);
/* remove leftover rev-cache file if there is any */
unlink_or_warn(git_path("info/rev-cache"));
return errs;
}