From 22184497a36a90e541617a51de6671ca5948612c Mon Sep 17 00:00:00 2001 From: Thomas Gummerer Date: Wed, 11 Sep 2019 19:20:25 +0100 Subject: [PATCH 1/3] factor out refresh_and_write_cache function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Getting the lock for the index, refreshing it and then writing it is a pattern that happens more than once throughout the codebase, and isn't trivial to get right. Factor out the refresh_and_write_cache function from builtin/am.c to read-cache.c, so it can be re-used in other places in a subsequent commit. Note that we return different error codes for failing to refresh the cache, and failing to write the index. The current caller only cares about failing to write the index. However for other callers we're going to convert in subsequent patches we will need this distinction. Helped-by: Martin Ågren Helped-by: Johannes Schindelin Signed-off-by: Thomas Gummerer Signed-off-by: Junio C Hamano --- builtin/am.c | 16 ++-------------- cache.h | 18 ++++++++++++++++++ read-cache.c | 21 +++++++++++++++++++++ 3 files changed, 41 insertions(+), 14 deletions(-) diff --git a/builtin/am.c b/builtin/am.c index 1aea657a7f..92e0e70069 100644 --- a/builtin/am.c +++ b/builtin/am.c @@ -1071,19 +1071,6 @@ static const char *msgnum(const struct am_state *state) return sb.buf; } -/** - * Refresh and write index. - */ -static void refresh_and_write_cache(void) -{ - struct lock_file lock_file = LOCK_INIT; - - hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR); - refresh_cache(REFRESH_QUIET); - if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK)) - die(_("unable to write index file")); -} - /** * Dies with a user-friendly message on how to proceed after resolving the * problem. This message can be overridden with state->resolvemsg. @@ -1703,7 +1690,8 @@ static void am_run(struct am_state *state, int resume) unlink(am_path(state, "dirtyindex")); - refresh_and_write_cache(); + if (refresh_and_write_cache(REFRESH_QUIET, 0, 0) < 0) + die(_("unable to write index file")); if (repo_index_has_changes(the_repository, NULL, &sb)) { write_state_bool(state, "dirtyindex", 1); diff --git a/cache.h b/cache.h index b1da1ab08f..68a54f50ac 100644 --- a/cache.h +++ b/cache.h @@ -414,6 +414,7 @@ extern struct index_state the_index; #define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags)) #define chmod_cache_entry(ce, flip) chmod_index_entry(&the_index, (ce), (flip)) #define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL) +#define refresh_and_write_cache(refresh_flags, write_flags, gentle) repo_refresh_and_write_index(the_repository, (refresh_flags), (write_flags), (gentle), NULL, NULL, NULL) #define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options)) #define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options)) #define cache_dir_exists(name, namelen) index_dir_exists(&the_index, (name), (namelen)) @@ -812,6 +813,23 @@ void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, st #define REFRESH_IN_PORCELAIN 0x0020 /* user friendly output, not "needs update" */ #define REFRESH_PROGRESS 0x0040 /* show progress bar if stderr is tty */ int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg); +/* + * Refresh the index and write it to disk. + * + * 'refresh_flags' is passed directly to 'refresh_index()', while + * 'COMMIT_LOCK | write_flags' is passed to 'write_locked_index()', so + * the lockfile is always either committed or rolled back. + * + * If 'gentle' is passed, errors locking the index are ignored. + * + * Return 1 if refreshing the index returns an error, -1 if writing + * the index to disk fails, 0 on success. + * + * Note that if refreshing the index returns an error, we still write + * out the index (unless locking fails). + */ +int repo_refresh_and_write_index(struct repository*, unsigned int refresh_flags, unsigned int write_flags, int gentle, const struct pathspec *, char *seen, const char *header_msg); + struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int); void set_alternate_index_output(const char *); diff --git a/read-cache.c b/read-cache.c index 52ffa8a313..7e646e06c2 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1472,6 +1472,27 @@ static void show_file(const char * fmt, const char * name, int in_porcelain, printf(fmt, name); } +int repo_refresh_and_write_index(struct repository *repo, + unsigned int refresh_flags, + unsigned int write_flags, + int gentle, + const struct pathspec *pathspec, + char *seen, const char *header_msg) +{ + struct lock_file lock_file = LOCK_INIT; + int fd, ret = 0; + + fd = repo_hold_locked_index(repo, &lock_file, 0); + if (!gentle && fd < 0) + return -1; + if (refresh_index(repo->index, refresh_flags, pathspec, seen, header_msg)) + ret = 1; + if (0 <= fd && write_locked_index(repo->index, &lock_file, COMMIT_LOCK | write_flags)) + ret = -1; + return ret; +} + + int refresh_index(struct index_state *istate, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg) From e080b34540296e4671b4d1110ba3c71b5224884a Mon Sep 17 00:00:00 2001 From: Thomas Gummerer Date: Wed, 11 Sep 2019 19:20:26 +0100 Subject: [PATCH 2/3] merge: use refresh_and_write_cache Use the 'refresh_and_write_cache()' convenience function introduced in the last commit, instead of refreshing and writing the index manually in merge.c Signed-off-by: Thomas Gummerer Signed-off-by: Junio C Hamano --- builtin/merge.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/builtin/merge.c b/builtin/merge.c index e2ccbc44e2..83e42fcb10 100644 --- a/builtin/merge.c +++ b/builtin/merge.c @@ -688,16 +688,13 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common, struct commit_list *remoteheads, struct commit *head) { - struct lock_file lock = LOCK_INIT; const char *head_arg = "HEAD"; - hold_locked_index(&lock, LOCK_DIE_ON_ERROR); - refresh_cache(REFRESH_QUIET); - if (write_locked_index(&the_index, &lock, - COMMIT_LOCK | SKIP_IF_UNCHANGED)) + if (refresh_and_write_cache(REFRESH_QUIET, SKIP_IF_UNCHANGED, 0) < 0) return error(_("Unable to write index.")); if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) { + struct lock_file lock = LOCK_INIT; int clean, x; struct commit *result; struct commit_list *reversed = NULL; @@ -860,12 +857,8 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads) { struct object_id result_tree, result_commit; struct commit_list *parents, **pptr = &parents; - struct lock_file lock = LOCK_INIT; - hold_locked_index(&lock, LOCK_DIE_ON_ERROR); - refresh_cache(REFRESH_QUIET); - if (write_locked_index(&the_index, &lock, - COMMIT_LOCK | SKIP_IF_UNCHANGED)) + if (refresh_and_write_cache(REFRESH_QUIET, SKIP_IF_UNCHANGED, 0) < 0) return error(_("Unable to write index.")); write_tree_trivial(&result_tree); From 34933d0eff5d4c91fae6ad6f71a6e6a69a496ced Mon Sep 17 00:00:00 2001 From: Thomas Gummerer Date: Wed, 11 Sep 2019 19:20:27 +0100 Subject: [PATCH 3/3] stash: make sure to write refreshed cache When converting stash into C, calls to 'git update-index --refresh' were replaced with the 'refresh_cache()' function. That is fine as long as the index is only needed in-core, and not re-read from disk. However in many cases we do actually need the refreshed index to be written to disk, for example 'merge_recursive_generic()' discards the in-core index before re-reading it from disk, and in the case of 'apply --quiet', the 'refresh_cache()' we currently have is pointless without writing the index to disk. Always write the index after refreshing it to ensure there are no regressions in this compared to the scripted stash. In the future we can consider avoiding the write where possible after making sure none of the subsequent calls actually need the refreshed cache, and it is not expected to be refreshed after stash exits or it is written somewhere else already. Reported-by: Jeff King Signed-off-by: Thomas Gummerer Signed-off-by: Junio C Hamano --- builtin/stash.c | 11 +++++++---- t/t3903-stash.sh | 16 ++++++++++++++++ 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/builtin/stash.c b/builtin/stash.c index b5a301f24d..ab30d1e920 100644 --- a/builtin/stash.c +++ b/builtin/stash.c @@ -396,7 +396,7 @@ static int do_apply_stash(const char *prefix, struct stash_info *info, const struct object_id *bases[1]; read_cache_preload(NULL); - if (refresh_cache(REFRESH_QUIET)) + if (refresh_and_write_cache(REFRESH_QUIET, 0, 0)) return -1; if (write_cache_as_tree(&c_tree, 0, NULL)) @@ -485,7 +485,7 @@ static int do_apply_stash(const char *prefix, struct stash_info *info, } if (quiet) { - if (refresh_cache(REFRESH_QUIET)) + if (refresh_and_write_cache(REFRESH_QUIET, 0, 0)) warning("could not refresh index"); } else { struct child_process cp = CHILD_PROCESS_INIT; @@ -1129,7 +1129,10 @@ static int do_create_stash(const struct pathspec *ps, struct strbuf *stash_msg_b prepare_fallback_ident("git stash", "git@stash"); read_cache_preload(NULL); - refresh_cache(REFRESH_QUIET); + if (refresh_and_write_cache(REFRESH_QUIET, 0, 0) < 0) { + ret = -1; + goto done; + } if (get_oid("HEAD", &info->b_commit)) { if (!quiet) @@ -1290,7 +1293,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q free(ps_matched); } - if (refresh_cache(REFRESH_QUIET)) { + if (refresh_and_write_cache(REFRESH_QUIET, 0, 0)) { ret = -1; goto done; } diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh index b8e337893f..392954d6dd 100755 --- a/t/t3903-stash.sh +++ b/t/t3903-stash.sh @@ -1241,4 +1241,20 @@ test_expect_success 'stash --keep-index with file deleted in index does not resu test_path_is_missing to-remove ' +test_expect_success 'stash apply should succeed with unmodified file' ' + echo base >file && + git add file && + git commit -m base && + + # now stash a modification + echo modified >file && + git stash && + + # make the file stat dirty + cp file other && + mv other file && + + git stash apply +' + test_done