From fc71db39e0d75e8a403f36f3fecf4450886cd165 Mon Sep 17 00:00:00 2001
From: Alex Riesen <raa.lkml@gmail.com>
Date: Wed, 29 Apr 2009 23:21:46 +0200
Subject: [PATCH 1/3] Introduce an unlink(2) wrapper which gives warning if
 unlink failed

This seem to be a very common pattern in the current code.

The function prints a generic removal failure message, the file name
which failed and readable errno presentation. The function preserves
errno and always returns the value unlink(2) returned, but prints
no message for ENOENT, as it was the most often filtered out in the
code calling unlink. Besides, removing a file is anyway the purpose of
calling unlink.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-compat-util.h |  6 ++++++
 wrapper.c         | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/git-compat-util.h b/git-compat-util.h
index 1ac16bde5a..c7cf2d5d9c 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -415,4 +415,10 @@ void git_qsort(void *base, size_t nmemb, size_t size,
 #define fstat_is_reliable() 1
 #endif
 
+/*
+ * Preserves errno, prints a message, but gives no warning for ENOENT.
+ * Always returns the return value of unlink(2).
+ */
+int unlink_or_warn(const char *path);
+
 #endif
diff --git a/wrapper.c b/wrapper.c
index d8efb1365a..7eb3218ee9 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -289,3 +289,19 @@ int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
 	safe_create_leading_directories(name);
 	return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 }
+
+int unlink_or_warn(const char *file)
+{
+	int rc = unlink(file);
+
+	if (rc < 0) {
+		int err = errno;
+		if (ENOENT != err) {
+			warning("unable to unlink %s: %s",
+				file, strerror(errno));
+			errno = err;
+		}
+	}
+	return rc;
+}
+

From 691f1a28bf57618d8b44a193b1d28013c858aba6 Mon Sep 17 00:00:00 2001
From: Alex Riesen <raa.lkml@gmail.com>
Date: Wed, 29 Apr 2009 23:22:56 +0200
Subject: [PATCH 2/3] replace direct calls to unlink(2) with unlink_or_warn

This helps to notice when something's going wrong, especially on
systems which lock open files.

I used the following criteria when selecting the code for replacement:
- it was already printing a warning for the unlink failures
- it is in a function which already printing something or is
  called from such a function
- it is in a static function, returning void and the function is only
  called from a builtin main function (cmd_)
- it is in a function which handles emergency exit (signal handlers)
- it is in a function which is obvously cleaning up the lockfiles

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-apply.c        |  4 ++--
 builtin-fetch-pack.c   |  2 +-
 builtin-prune-packed.c |  4 ++--
 builtin-prune.c        |  4 ++--
 builtin-receive-pack.c |  2 +-
 builtin-remote.c       |  4 ++--
 builtin-rerere.c       |  2 +-
 builtin-tag.c          |  2 +-
 builtin-verify-tag.c   |  2 +-
 diff.c                 |  2 +-
 entry.c                |  2 +-
 fast-import.c          |  4 ++--
 http-push.c            | 12 ++++++------
 http-walker.c          | 14 +++++++-------
 ll-merge.c             |  2 +-
 lockfile.c             |  4 ++--
 pack-refs.c            |  2 +-
 refs.c                 | 15 +++++----------
 rerere.c               |  2 +-
 server-info.c          |  2 +-
 sha1_file.c            |  2 +-
 transport.c            |  2 +-
 unpack-trees.c         |  2 +-
 23 files changed, 44 insertions(+), 49 deletions(-)

diff --git a/builtin-apply.c b/builtin-apply.c
index 7b404ef660..8a3771e87e 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -2781,7 +2781,7 @@ static void remove_file(struct patch *patch, int rmdir_empty)
 			if (rmdir(patch->old_name))
 				warning("unable to remove submodule %s",
 					patch->old_name);
-		} else if (!unlink(patch->old_name) && rmdir_empty) {
+		} else if (!unlink_or_warn(patch->old_name) && rmdir_empty) {
 			remove_path(patch->old_name);
 		}
 	}
@@ -2891,7 +2891,7 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
 			if (!try_create_file(newpath, mode, buf, size)) {
 				if (!rename(newpath, path))
 					return;
-				unlink(newpath);
+				unlink_or_warn(newpath);
 				break;
 			}
 			if (errno != EEXIST)
diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 5d134be47c..bd97cfd9bf 100644
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -814,7 +814,7 @@ struct ref *fetch_pack(struct fetch_pack_args *my_args,
 		fd = hold_lock_file_for_update(&lock, shallow,
 					       LOCK_DIE_ON_ERROR);
 		if (!write_shallow_commits(fd, 0)) {
-			unlink(shallow);
+			unlink_or_warn(shallow);
 			rollback_lock_file(&lock);
 		} else {
 			commit_lock_file(&lock);
diff --git a/builtin-prune-packed.c b/builtin-prune-packed.c
index 4942892e9f..00590b1c3c 100644
--- a/builtin-prune-packed.c
+++ b/builtin-prune-packed.c
@@ -28,8 +28,8 @@ static void prune_dir(int i, DIR *dir, char *pathname, int len, int opts)
 		memcpy(pathname + len, de->d_name, 38);
 		if (opts & DRY_RUN)
 			printf("rm -f %s\n", pathname);
-		else if (unlink(pathname) < 0)
-			error("unable to unlink %s", pathname);
+		else
+			unlink_or_warn(pathname);
 		display_progress(progress, i + 1);
 	}
 	pathname[len] = 0;
diff --git a/builtin-prune.c b/builtin-prune.c
index 545e9c1f94..145ba83651 100644
--- a/builtin-prune.c
+++ b/builtin-prune.c
@@ -27,7 +27,7 @@ static int prune_tmp_object(const char *path, const char *filename)
 	}
 	printf("Removing stale temporary file %s\n", fullpath);
 	if (!show_only)
-		unlink(fullpath);
+		unlink_or_warn(fullpath);
 	return 0;
 }
 
@@ -47,7 +47,7 @@ static int prune_object(char *path, const char *filename, const unsigned char *s
 		       (type > 0) ? typename(type) : "unknown");
 	}
 	if (!show_only)
-		unlink(fullpath);
+		unlink_or_warn(fullpath);
 	return 0;
 }
 
diff --git a/builtin-receive-pack.c b/builtin-receive-pack.c
index a970b39505..035b723e50 100644
--- a/builtin-receive-pack.c
+++ b/builtin-receive-pack.c
@@ -702,7 +702,7 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 			unpack_status = unpack();
 		execute_commands(unpack_status);
 		if (pack_lockfile)
-			unlink(pack_lockfile);
+			unlink_or_warn(pack_lockfile);
 		if (report_status)
 			report(unpack_status);
 		run_receive_hook(post_receive_hook);
diff --git a/builtin-remote.c b/builtin-remote.c
index 2ed752cbf1..71abf68404 100644
--- a/builtin-remote.c
+++ b/builtin-remote.c
@@ -525,8 +525,8 @@ static int migrate_file(struct remote *remote)
 		path = git_path("remotes/%s", remote->name);
 	else if (remote->origin == REMOTE_BRANCHES)
 		path = git_path("branches/%s", remote->name);
-	if (path && unlink(path))
-		warning("failed to remove '%s'", path);
+	if (path)
+		unlink_or_warn(path);
 	return 0;
 }
 
diff --git a/builtin-rerere.c b/builtin-rerere.c
index 020af7377b..adfb7b5f48 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -116,7 +116,7 @@ int cmd_rerere(int argc, const char **argv, const char *prefix)
 			if (!has_rerere_resolution(name))
 				unlink_rr_item(name);
 		}
-		unlink(git_path("rr-cache/MERGE_RR"));
+		unlink_or_warn(git_path("rr-cache/MERGE_RR"));
 	} else if (!strcmp(argv[1], "gc"))
 		garbage_collect(&merge_rr);
 	else if (!strcmp(argv[1], "status"))
diff --git a/builtin-tag.c b/builtin-tag.c
index 01e73747d0..e544430094 100644
--- a/builtin-tag.c
+++ b/builtin-tag.c
@@ -338,7 +338,7 @@ static void create_tag(const unsigned char *object, const char *tag,
 		exit(128);
 	}
 	if (path) {
-		unlink(path);
+		unlink_or_warn(path);
 		free(path);
 	}
 }
diff --git a/builtin-verify-tag.c b/builtin-verify-tag.c
index 729a1593e6..7f7fda42f9 100644
--- a/builtin-verify-tag.c
+++ b/builtin-verify-tag.c
@@ -55,7 +55,7 @@ static int run_gpg_verify(const char *buf, unsigned long size, int verbose)
 	close(gpg.in);
 	ret = finish_command(&gpg);
 
-	unlink(path);
+	unlink_or_warn(path);
 
 	return ret;
 }
diff --git a/diff.c b/diff.c
index 3ac71686eb..6802f5ac12 100644
--- a/diff.c
+++ b/diff.c
@@ -189,7 +189,7 @@ static void remove_tempfile(void)
 	int i;
 	for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 		if (diff_temp[i].name == diff_temp[i].tmp_path)
-			unlink(diff_temp[i].name);
+			unlink_or_warn(diff_temp[i].name);
 		diff_temp[i].name = NULL;
 	}
 }
diff --git a/entry.c b/entry.c
index 915514aa5c..cc841edf90 100644
--- a/entry.c
+++ b/entry.c
@@ -35,7 +35,7 @@ static void create_directories(const char *path, int path_len,
 		 */
 		if (mkdir(buf, 0777)) {
 			if (errno == EEXIST && state->force &&
-			    !unlink(buf) && !mkdir(buf, 0777))
+			    !unlink_or_warn(buf) && !mkdir(buf, 0777))
 				continue;
 			die("cannot create directory at %s", buf);
 		}
diff --git a/fast-import.c b/fast-import.c
index 8d959af3b2..6a618e9163 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -931,7 +931,7 @@ static void unkeep_all_packs(void)
 		struct packed_git *p = all_packs[k];
 		snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
 			 get_object_directory(), sha1_to_hex(p->sha1));
-		unlink(name);
+		unlink_or_warn(name);
 	}
 }
 
@@ -981,7 +981,7 @@ static void end_packfile(void)
 	}
 	else {
 		close(old_p->pack_fd);
-		unlink(old_p->pack_name);
+		unlink_or_warn(old_p->pack_name);
 	}
 	free(old_p);
 
diff --git a/http-push.c b/http-push.c
index 5138224cc3..29e8ebfebb 100644
--- a/http-push.c
+++ b/http-push.c
@@ -315,9 +315,9 @@ static void start_fetch_loose(struct transfer_request *request)
 		 "%s.temp", filename);
 
 	snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
-	unlink(prevfile);
+	unlink_or_warn(prevfile);
 	rename(request->tmpfile, prevfile);
-	unlink(request->tmpfile);
+	unlink_or_warn(request->tmpfile);
 
 	if (request->local_fileno != -1)
 		error("fd leakage in start: %d", request->local_fileno);
@@ -372,7 +372,7 @@ static void start_fetch_loose(struct transfer_request *request)
 		} while (prev_read > 0);
 		close(prevlocal);
 	}
-	unlink(prevfile);
+	unlink_or_warn(prevfile);
 
 	/* Reset inflate/SHA1 if there was an error reading the previous temp
 	   file; also rewind to the beginning of the local file. */
@@ -784,7 +784,7 @@ static void finish_request(struct transfer_request *request)
 		    request->http_code != 416) {
 			if (stat(request->tmpfile, &st) == 0) {
 				if (st.st_size == 0)
-					unlink(request->tmpfile);
+					unlink_or_warn(request->tmpfile);
 			}
 		} else {
 			if (request->http_code == 416)
@@ -793,9 +793,9 @@ static void finish_request(struct transfer_request *request)
 			git_inflate_end(&request->stream);
 			git_SHA1_Final(request->real_sha1, &request->c);
 			if (request->zret != Z_STREAM_END) {
-				unlink(request->tmpfile);
+				unlink_or_warn(request->tmpfile);
 			} else if (hashcmp(request->obj->sha1, request->real_sha1)) {
-				unlink(request->tmpfile);
+				unlink_or_warn(request->tmpfile);
 			} else {
 				request->rename =
 					move_temp_to_file(
diff --git a/http-walker.c b/http-walker.c
index c5a3ea3b31..7321ccc9fe 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -111,9 +111,9 @@ static void start_object_request(struct walker *walker,
 	struct walker_data *data = walker->data;
 
 	snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
-	unlink(prevfile);
+	unlink_or_warn(prevfile);
 	rename(obj_req->tmpfile, prevfile);
-	unlink(obj_req->tmpfile);
+	unlink_or_warn(obj_req->tmpfile);
 
 	if (obj_req->local != -1)
 		error("fd leakage in start: %d", obj_req->local);
@@ -177,7 +177,7 @@ static void start_object_request(struct walker *walker,
 		} while (prev_read > 0);
 		close(prevlocal);
 	}
-	unlink(prevfile);
+	unlink_or_warn(prevfile);
 
 	/* Reset inflate/SHA1 if there was an error reading the previous temp
 	   file; also rewind to the beginning of the local file. */
@@ -238,18 +238,18 @@ static void finish_object_request(struct object_request *obj_req)
 	} else if (obj_req->curl_result != CURLE_OK) {
 		if (stat(obj_req->tmpfile, &st) == 0)
 			if (st.st_size == 0)
-				unlink(obj_req->tmpfile);
+				unlink_or_warn(obj_req->tmpfile);
 		return;
 	}
 
 	git_inflate_end(&obj_req->stream);
 	git_SHA1_Final(obj_req->real_sha1, &obj_req->c);
 	if (obj_req->zret != Z_STREAM_END) {
-		unlink(obj_req->tmpfile);
+		unlink_or_warn(obj_req->tmpfile);
 		return;
 	}
 	if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
-		unlink(obj_req->tmpfile);
+		unlink_or_warn(obj_req->tmpfile);
 		return;
 	}
 	obj_req->rename =
@@ -809,7 +809,7 @@ static void abort_object_request(struct object_request *obj_req)
 		close(obj_req->local);
 		obj_req->local = -1;
 	}
-	unlink(obj_req->tmpfile);
+	unlink_or_warn(obj_req->tmpfile);
 	if (obj_req->slot) {
 		release_active_slot(obj_req->slot);
 		obj_req->slot = NULL;
diff --git a/ll-merge.c b/ll-merge.c
index fa2ca5250c..81c02ad053 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -219,7 +219,7 @@ static int ll_ext_merge(const struct ll_merge_driver *fn,
 	close(fd);
  bad:
 	for (i = 0; i < 3; i++)
-		unlink(temp[i]);
+		unlink_or_warn(temp[i]);
 	strbuf_release(&cmd);
 	return status;
 }
diff --git a/lockfile.c b/lockfile.c
index 3dbb2d1ff9..984eb320fc 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -16,7 +16,7 @@ static void remove_lock_file(void)
 		    lock_file_list->filename[0]) {
 			if (lock_file_list->fd >= 0)
 				close(lock_file_list->fd);
-			unlink(lock_file_list->filename);
+			unlink_or_warn(lock_file_list->filename);
 		}
 		lock_file_list = lock_file_list->next;
 	}
@@ -259,7 +259,7 @@ void rollback_lock_file(struct lock_file *lk)
 	if (lk->filename[0]) {
 		if (lk->fd >= 0)
 			close(lk->fd);
-		unlink(lk->filename);
+		unlink_or_warn(lk->filename);
 	}
 	lk->filename[0] = 0;
 }
diff --git a/pack-refs.c b/pack-refs.c
index 2c76fb181f..301fc60eae 100644
--- a/pack-refs.c
+++ b/pack-refs.c
@@ -66,7 +66,7 @@ static void prune_ref(struct ref_to_prune *r)
 	struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
 
 	if (lock) {
-		unlink(git_path("%s", r->name));
+		unlink_or_warn(git_path("%s", r->name));
 		unlock_ref(lock);
 	}
 }
diff --git a/refs.c b/refs.c
index e65a3b4c4e..2b1f0f0e6e 100644
--- a/refs.c
+++ b/refs.c
@@ -1002,12 +1002,10 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 		} else {
 			path = git_path("%s", refname);
 		}
-		err = unlink(path);
-		if (err && errno != ENOENT) {
+		err = unlink_or_warn(path);
+		if (err && errno != ENOENT)
 			ret = 1;
-			error("unlink(%s) failed: %s",
-			      path, strerror(errno));
-		}
+
 		if (!(delopt & REF_NODEREF))
 			lock->lk->filename[i] = '.';
 	}
@@ -1017,10 +1015,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 	 */
 	ret |= repack_without_ref(refname);
 
-	err = unlink(git_path("logs/%s", lock->ref_name));
-	if (err && errno != ENOENT)
-		warning("unlink(%s) failed: %s",
-			git_path("logs/%s", lock->ref_name), strerror(errno));
+	unlink_or_warn(git_path("logs/%s", lock->ref_name));
 	invalidate_cached_refs();
 	unlock_ref(lock);
 	return ret;
@@ -1381,7 +1376,7 @@ int create_symref(const char *ref_target, const char *refs_heads_master,
 	if (adjust_shared_perm(git_HEAD)) {
 		error("Unable to fix permissions on %s", lockpath);
 	error_unlink_return:
-		unlink(lockpath);
+		unlink_or_warn(lockpath);
 	error_free_return:
 		free(git_HEAD);
 		return -1;
diff --git a/rerere.c b/rerere.c
index 713c6e16ac..87360dc23e 100644
--- a/rerere.c
+++ b/rerere.c
@@ -173,7 +173,7 @@ static int handle_file(const char *path,
 		git_SHA1_Final(sha1, &ctx);
 	if (hunk != RR_CONTEXT) {
 		if (output)
-			unlink(output);
+			unlink_or_warn(output);
 		return error("Could not parse conflict hunks in %s", path);
 	}
 	if (wrerror)
diff --git a/server-info.c b/server-info.c
index 66b0d9d878..d096dc7718 100644
--- a/server-info.c
+++ b/server-info.c
@@ -246,7 +246,7 @@ int update_server_info(int force)
 	errs = errs | update_info_packs(force);
 
 	/* remove leftover rev-cache file if there is any */
-	unlink(git_path("info/rev-cache"));
+	unlink_or_warn(git_path("info/rev-cache"));
 
 	return errs;
 }
diff --git a/sha1_file.c b/sha1_file.c
index f708cf4f67..dd474116a8 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2247,7 +2247,7 @@ int move_temp_to_file(const char *tmpfile, const char *filename)
 			goto out;
 		ret = errno;
 	}
-	unlink(tmpfile);
+	unlink_or_warn(tmpfile);
 	if (ret) {
 		if (ret != EEXIST) {
 			return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
diff --git a/transport.c b/transport.c
index 3dfb03c06e..efecb65258 100644
--- a/transport.c
+++ b/transport.c
@@ -1069,7 +1069,7 @@ int transport_fetch_refs(struct transport *transport, const struct ref *refs)
 void transport_unlock_pack(struct transport *transport)
 {
 	if (transport->pack_lockfile) {
-		unlink(transport->pack_lockfile);
+		unlink_or_warn(transport->pack_lockfile);
 		free(transport->pack_lockfile);
 		transport->pack_lockfile = NULL;
 	}
diff --git a/unpack-trees.c b/unpack-trees.c
index e4eb8fa3af..aaacaf1015 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -61,7 +61,7 @@ static void unlink_entry(struct cache_entry *ce)
 {
 	if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
 		return;
-	if (unlink(ce->name))
+	if (unlink_or_warn(ce->name))
 		return;
 	schedule_dir_for_removal(ce->name, ce_namelen(ce));
 }

From f6a5f1bb509a3af182fe568135398f1f2be15e5d Mon Sep 17 00:00:00 2001
From: Alex Riesen <raa.lkml@gmail.com>
Date: Wed, 29 Apr 2009 23:24:52 +0200
Subject: [PATCH 3/3] print unlink(2) errno in copy_or_link_directory

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-clone.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/builtin-clone.c b/builtin-clone.c
index 880373f279..ba286e0160 100644
--- a/builtin-clone.c
+++ b/builtin-clone.c
@@ -228,7 +228,8 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest)
 		}
 
 		if (unlink(dest->buf) && errno != ENOENT)
-			die("failed to unlink %s", dest->buf);
+			die("failed to unlink %s: %s",
+			    dest->buf, strerror(errno));
 		if (!option_no_hardlinks) {
 			if (!link(src->buf, dest->buf))
 				continue;