Re: [PATCH v2 2/3] fsmonitor: add assertion that fsmonitor is valid to check_removed

> Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
> ---
>  diff-lib.c  | 18 +++++++++++-------
>  fsmonitor.h | 11 +++++++++++
>  2 files changed, 22 insertions(+), 7 deletions(-)
>
> diff --git a/diff-lib.c b/diff-lib.c
> index 3fb538ad18e9..e5a58c9259cf 100644
> --- a/diff-lib.c
> +++ b/diff-lib.c
> @@ -28,8 +28,9 @@
>   * exists for ce that is a submodule -- it is a submodule that is not
>   * checked out).  Return negative for an error.
>   */
> -static int check_removed(const struct cache_entry *ce, struct stat *st)
> +static int check_removed(const struct index_state *istate, const struct cache_entry *ce, struct stat *st)
>  {
> +	assert(is_fsmonitor_refreshed(istate));
>  	if (!(ce->ce_flags & CE_FSMONITOR_VALID) && lstat(ce->name, st) < 0) {
>  		if (!is_missing_file_error(errno))
>  			return -1;
> @@ -136,7 +137,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
>  			memset(&(dpath->parent[0]), 0,
>  			       sizeof(struct combine_diff_parent)*5);
>  
> -			changed = check_removed(ce, &st);
> +			changed = check_removed(istate, ce, &st);
>  			if (!changed)
>  				wt_mode = ce_mode_from_stat(ce, st.st_mode);
>  			else {
> @@ -216,7 +217,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
>  		} else {
>  			struct stat st;
>  
> -			changed = check_removed(ce, &st);
> +			changed = check_removed(istate, ce, &st);
>  			if (changed) {
>  				if (changed < 0) {
>  					perror(ce->name);
> @@ -278,7 +279,8 @@ static void diff_index_show_file(struct rev_info *revs,
>  		       oid, oid_valid, ce->name, dirty_submodule);
>  }
>  
> -static int get_stat_data(const struct cache_entry *ce,
> +static int get_stat_data(const struct index_state *istate,
> +			 const struct cache_entry *ce,
>  			 const struct object_id **oidp,
>  			 unsigned int *modep,
>  			 int cached, int match_missing,
> @@ -290,7 +292,7 @@ static int get_stat_data(const struct cache_entry *ce,
>  	if (!cached && !ce_uptodate(ce)) {
>  		int changed;
>  		struct stat st;
> -		changed = check_removed(ce, &st);
> +		changed = check_removed(istate, ce, &st);
>  		if (changed < 0)
>  			return -1;
>  		else if (changed) {
> @@ -321,12 +323,13 @@ static void show_new_file(struct rev_info *revs,
>  	const struct object_id *oid;
>  	unsigned int mode;
>  	unsigned dirty_submodule = 0;
> +	struct index_state *istate = revs->diffopt.repo->index;
>  
>  	/*
>  	 * New file in the index: it might actually be different in
>  	 * the working tree.
>  	 */
> -	if (get_stat_data(new_file, &oid, &mode, cached, match_missing,
> +	if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
>  	    &dirty_submodule, &revs->diffopt) < 0)
>  		return;
>  
> @@ -342,8 +345,9 @@ static int show_modified(struct rev_info *revs,
>  	unsigned int mode, oldmode;
>  	const struct object_id *oid;
>  	unsigned dirty_submodule = 0;
> +	struct index_state *istate = revs->diffopt.repo->index;
>  
> -	if (get_stat_data(new_entry, &oid, &mode, cached, match_missing,
> +	if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
>  			  &dirty_submodule, &revs->diffopt) < 0) {
>  		if (report_missing)
>  			diff_index_show_file(revs, "-", old_entry,
> diff --git a/fsmonitor.h b/fsmonitor.h
> index 7f1794b90b00..f20d72631d76 100644
> --- a/fsmonitor.h
> +++ b/fsmonitor.h
> @@ -49,6 +49,17 @@ void refresh_fsmonitor(struct index_state *istate);
>   */
>  int fsmonitor_is_trivial_response(const struct strbuf *query_result);
>  
> +/*
> + * Check if refresh_fsmonitor has been called at least once.
> + * refresh_fsmonitor is idempotent. Returns true if fsmonitor is
> + * not enabled (since the state will be "fresh" w/ CE_FSMONITOR_VALID unset)
> + * This version is useful for assertions
> + */
> +static inline int is_fsmonitor_refreshed(const struct index_state *istate)
> +{
> +	return !core_fsmonitor || istate->fsmonitor_has_run_once;
> +}
> +
>  /*
>   * Set the given cache entries CE_FSMONITOR_VALID bit. This should be
>   * called any time the cache entry has been updated to reflect the