Re: [PATCH v2 1/2] lockfile.c: remove PATH_MAX limitation (except in resolve_symlink)

Signed-off-by: Nguyễn Thái Ngọc Duy <redacted>
---
This helps remove the length check in v1 of the next patch.

cache.h    |  2 +-
lockfile.c | 56 ++++++++++++++++++++++++++++++++------------------------
2 files changed, 33 insertions(+), 25 deletions(-)

diff --git a/cache.h b/cache.h
index 44aa439..9ecb636 100644
--- a/cache.h
+++ b/cache.h

@@ -554,7 +554,7 @@ 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);
}
-- 
1.9.1.346.ga2b5940

--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html