@matheusbsbs / matheus-bagliano / commits / 33286dcd6d

commit-graph: fix UX issue when .lock file exists

We use the lockfile API to avoid multiple Git processes from writing to the commit-graph file in the .git/objects/info directory. In some cases, this directory may not exist, so we check for its existence. The existing code does the following when acquiring the lock: 1. Try to acquire the lock. 2. If it fails, try to create the .git/object/info directory. 3. Try to acquire the lock, failing if necessary. The problem is that if the lockfile exists, then the mkdir fails, giving an error that doesn't help the user: "fatal: cannot mkdir .git/objects/info: File exists" While technically this honors the lockfile, it does not help the user. Instead, do the following: 1. Check for existence of .git/objects/info; create if necessary. 2. Try to acquire the lock, failing if necessary. The new output looks like: fatal: Unable to create '<dir>/.git/objects/info/commit-graph.lock': File exists. Another git process seems to be running in this repository, e.g. an editor opened by 'git commit'. Please make sure all processes are terminated then try again. If it still fails, a git process may have crashed in this repository earlier: remove the file manually to continue. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Derrick Stolee committed May 10, 2018 at 17:42 UTC 33286dcd6d79eeb81b74f36a324f260275582639

1 file changed +5 -17

commit-graph.c

+5 -17

@@ -1,5 +1,6 @@

1 #include "cache.h"

2 #include "config.h"

3 +#include "dir.h"

4 #include "git-compat-util.h"

5 #include "lockfile.h"

6 #include "pack.h"

@@ -640,7 +641,6 @@ void write_commit_graph(const char *obj_dir,

641 struct hashfile *f;

642 uint32_t i, count_distinct = 0;

643 char *graph_name;

643 - int fd;

644 struct lock_file lk = LOCK_INIT;

645 uint32_t chunk_ids[5];

646 uint64_t chunk_offsets[5];

@@ -754,23 +754,11 @@ void write_commit_graph(const char *obj_dir,

754 compute_generation_numbers(&commits);

755

756 graph_name = get_commit_graph_filename(obj_dir);

757 - fd = hold_lock_file_for_update(&lk, graph_name, 0);

758 -

759 - if (fd < 0) {

760 - struct strbuf folder = STRBUF_INIT;

761 - strbuf_addstr(&folder, graph_name);

762 - strbuf_setlen(&folder, strrchr(folder.buf, '/') - folder.buf);

763 -

764 - if (mkdir(folder.buf, 0777) < 0)

765 - die_errno(_("cannot mkdir %s"), folder.buf);

766 - strbuf_release(&folder);

767 -

768 - fd = hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);

769 -

770 - if (fd < 0)

771 - die_errno("unable to create '%s'", graph_name);

772 - }

757 + if (safe_create_leading_directories(graph_name))

758 + die_errno(_("unable to create leading directories of %s"),

759 + graph_name);

760

761 + hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);

762 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);

763

764 hashwrite_be32(f, GRAPH_SIGNATURE);