git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v4 1/1] lockfile.c: store absolute path

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Sep 6, 2014, 10:31 UTC
Message-ID
<1409999489-25193-2-git-send-email-mhagger@alum.mit.edu>
In-Reply-To
<1409999489-25193-1-git-send-email-mhagger@alum.mit.edu>
From: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

Locked paths can be saved in a linked list so that if something wrong happens, *.lock are removed. For relative paths, this works fine if we keep cwd the same, which is true 99% of time except:

- update-index and read-tree hold the lock on $GIT_DIR/index really
  early, then later on may call setup_work_tree() to move cwd.
- Suppose a lock is being held (e.g. by "git add") then somewhere
  down the line, somebody calls real_path (e.g. "link_alt_odb_entry"),
  which temporarily moves cwd away and back.

During that time when cwd is moved (either permanently or temporarily) and we decide to die(), attempts to remove relative *.lock will fail, and the next operation will complain that some files are still locked.

Avoid this case by turning relative paths to absolute before storing the path in "filename" field.

Reported-by: Yue Lin Ho <yuelinho777@gmail.com>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Adapted-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 lockfile.c                    | 14 +++++++++++---
 t/t2107-update-index-basic.sh | 15 +++++++++++++++
 2 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/lockfile.c b/lockfile.c
index e54d260..31b63bb 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -172,9 +172,17 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
 		lock_file_list = lk;
 	}
 
-	strbuf_addstr(&lk->filename, path);
-	if (!(flags & LOCK_NODEREF))
-		resolve_symlink(&lk->filename);
+	if (flags & LOCK_NODEREF) {
+		strbuf_add_absolute_path(&lk->filename, path);
+	} else {
+		struct strbuf resolved_path = STRBUF_INIT;
+
+		strbuf_addstr(&resolved_path, path);
+		resolve_symlink(&resolved_path);
+		strbuf_add_absolute_path(&lk->filename, resolved_path.buf);
+		strbuf_release(&resolved_path);
+	}
+
 	strbuf_addstr(&lk->filename, LOCK_SUFFIX);
 	lk->fd = open(lk->filename.buf, O_RDWR | O_CREAT | O_EXCL, 0666);
 	if (lk->fd < 0) {
diff --git a/t/t2107-update-index-basic.sh b/t/t2107-update-index-basic.sh
index 1bafb90..dfe02f4 100755
--- a/t/t2107-update-index-basic.sh
+++ b/t/t2107-update-index-basic.sh
@@ -65,4 +65,19 @@ test_expect_success '--cacheinfo mode,sha1,path (new syntax)' '
 	test_cmp expect actual
 '
 
+test_expect_success '.lock files cleaned up' '
+	mkdir cleanup &&
+	(
+	cd cleanup &&
+	mkdir worktree &&
+	git init repo &&
+	cd repo &&
+	git config core.worktree ../../worktree &&
+	# --refresh triggers late setup_work_tree,
+	# active_cache_changed is zero, rollback_lock_file fails
+	git update-index --refresh &&
+	! test -f .git/index.lock
+	)
+'
+
 test_done
-- 
2.1.0
Previous: Michael HaggertyNext: Duy Nguyen
Message 4 of 9 in “What's cooking in git.git (Aug 2014, #02; Fri, 8)”
  1. Junio C HamanoAug 8, 2014
  2. Duy NguyenAug 8, 2014
  3. 0/1 Use absolute paths of lockfilesMichael Haggerty, Sep 6, 2014
  4. 1/1 lockfile.c: store absolute pathMichael Haggerty, Sep 6, 2014
  5. Duy NguyenSep 6, 2014
  6. Yue Lin HoSep 10, 2014
  7. Yue Lin HoOct 15, 2014
  8. Charles BaileyAug 9, 2014
  9. Jeff KingAug 10, 2014

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.