[PATCH v3 1/3] lockfile.c: remove PATH_MAX limitation (except in resolve_symlink)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
cache.h | 2 +-
lockfile.c | 56 ++++++++++++++++++++++++++++++++------------------------
2 files changed, 33 insertions(+), 25 deletions(-)
diff --git a/cache.h b/cache.h
index cc46be4..0d8dce7 100644
--- a/cache.h
+++ b/cache.h
@@ -539,7 +539,7 @@ struct lock_file {
int fd;
pid_t owner;
char on_list;
- char filename[PATH_MAX];
+ char *filename;
};
#define LOCK_DIE_ON_ERROR 1
#define LOCK_NODEREF 2
diff --git a/lockfile.c b/lockfile.c
index 8fbcb6a..968b28f 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -7,13 +7,19 @@
static struct lock_file *lock_file_list;
static const char *alternate_index_output;
+static void clear_filename(struct lock_file *lk)
+{
+ free(lk->filename);
+ lk->filename = NULL;
+}
+
static void remove_lock_file(void)
{
pid_t me = getpid();
while (lock_file_list) {
if (lock_file_list->owner == me &&
- lock_file_list->filename[0]) {
+ lock_file_list->filename) {
if (lock_file_list->fd >= 0)
close(lock_file_list->fd);
unlink_or_warn(lock_file_list->filename);
@@ -77,10 +83,16 @@ static char *last_path_elm(char *p)
* Always returns p.
*/
-static char *resolve_symlink(char *p, size_t s)
+static char *resolve_symlink(const char *in)
{
+ static char p[PATH_MAX];
+ size_t s = sizeof(p);
int depth = MAXDEPTH;
+ if (strlen(in) >= sizeof(p))
+ return NULL;
+ strcpy(p, in);
+
while (depth--) {
char link[PATH_MAX];
int link_len = readlink(p, link, sizeof(link));
@@ -124,17 +136,12 @@ static char *resolve_symlink(char *p, size_t s)
static int lock_file(struct lock_file *lk, const char *path, int flags)
{
- /*
- * subtract 5 from size to make sure there's room for adding
- * ".lock" for the lock file name
- */
- static const size_t max_path_len = sizeof(lk->filename) - 5;
-
- if (strlen(path) >= max_path_len)
+ int len;
+ if (!(flags & LOCK_NODEREF) && !(path = resolve_symlink(path)))
return -1;
+ len = strlen(path) + 5; /* .lock */
+ lk->filename = xmallocz(len);
strcpy(lk->filename, path);
- if (!(flags & LOCK_NODEREF))
- resolve_symlink(lk->filename, max_path_len);
strcat(lk->filename, ".lock");
lk->fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
if (0 <= lk->fd) {
@@ -153,7 +160,7 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
lk->filename);
}
else
- lk->filename[0] = 0;
+ clear_filename(lk);
return lk->fd;
}
@@ -231,16 +238,17 @@ int close_lock_file(struct lock_file *lk)
int commit_lock_file(struct lock_file *lk)
{
- char result_file[PATH_MAX];
- size_t i;
- if (lk->fd >= 0 && close_lock_file(lk))
+ char *result_file;
+ if ((lk->fd >= 0 && close_lock_file(lk)) || !lk->filename)
return -1;
- strcpy(result_file, lk->filename);
- i = strlen(result_file) - 5; /* .lock */
- result_file[i] = 0;
- if (rename(lk->filename, result_file))
+ result_file = xmemdupz(lk->filename,
+ strlen(lk->filename) - 5 /* .lock */);
+ if (rename(lk->filename, result_file)) {
+ free(result_file);
return -1;
- lk->filename[0] = 0;
+ }
+ free(result_file);
+ clear_filename(lk);
return 0;
}
@@ -260,11 +268,11 @@ void set_alternate_index_output(const char *name)
int commit_locked_index(struct lock_file *lk)
{
if (alternate_index_output) {
- if (lk->fd >= 0 && close_lock_file(lk))
+ if ((lk->fd >= 0 && close_lock_file(lk)) || !lk->filename)
return -1;
if (rename(lk->filename, alternate_index_output))
return -1;
- lk->filename[0] = 0;
+ clear_filename(lk);
return 0;
}
else
@@ -273,10 +281,10 @@ int commit_locked_index(struct lock_file *lk)
void rollback_lock_file(struct lock_file *lk)
{
- if (lk->filename[0]) {
+ if (lk->filename) {
if (lk->fd >= 0)
close(lk->fd);
unlink_or_warn(lk->filename);
}
- lk->filename[0] = 0;
+ clear_filename(lk);
}
--
2.1.0.rc0.78.gc0d8480
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>