[PATCH v3 12/12] read_cache: roll back lock in `update_index_if_able()`
- From
- Martin Ågren <martin.agren@gmail.com>
- Date
- Oct 6, 2017, 20:12 UTC
- Message-ID
- <d7e1a460350b084943479a562774d570028afa0e.1507320376.git.martin.agren@gmail.com>
- In-Reply-To
- <cover.1507320376.git.martin.agren@gmail.com>
`update_index_if_able()` used to always commit the lock or roll it back. Commit 03b866477 (read-cache: new API write_locked_index instead of write_index/write_cache, 2014-06-13) stopped rolling it back in case a write was not even attempted. This change in behavior is not motivated in the commit message and appears to be accidental: the `else`-path was removed, although that changed the behavior in case the `if` shortcuts.
Reintroduce the rollback and document this behavior. While at it, move the documentation on this function from the function definition to the function declaration in cache.h.
If `write_locked_index(..., COMMIT_LOCK)` fails, it will roll back the lock for us (see the previous commit).
Noticed-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> --- cache.h | 4 ++++ read-cache.c | 5 ++--- 2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/cache.h b/cache.h index 0e26224b9..8c2493766 100644 --- a/cache.h +++ b/cache.h @@ -734,6 +734,10 @@ extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st); extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg); extern struct cache_entry *refresh_cache_entry(struct cache_entry *, unsigned int); +/* + * Opportunistically update the index but do not complain if we can't. + * The lockfile is always committed or rolled back. + */ extern void update_index_if_able(struct index_state *, struct lock_file *); extern int hold_locked_index(struct lock_file *, int); diff --git a/read-cache.c b/read-cache.c index 0d8d2dede..87188d390 100644 --- a/read-cache.c +++ b/read-cache.c @@ -2176,14 +2176,13 @@ static int has_racy_timestamp(struct index_state *istate) return 0; } -/* - * Opportunistically update the index but do not complain if we can't - */ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile) { if ((istate->cache_changed || has_racy_timestamp(istate)) && verify_index(istate)) write_locked_index(istate, lockfile, COMMIT_LOCK); + else + rollback_lock_file(lockfile); } /*
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