git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH 25/27] fsmonitor: disable if index is sparse

From
Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Date
Jan 25, 2021, 17:42 UTC
Message-ID
<e24570336485ee153ada3289231b707e937524a8.1611596534.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.847.git.1611596533.gitgitgadget@gmail.com>
From: Derrick Stolee <dstolee@microsoft.com>

The FS Monitor feature uses a bitmap over the index entries. This currently interacts poorly with a sparse index. We will revisit this interaction in the future, but for now protect the index by refusing to use the FS Monitor extension at all if the index is sparse.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 fsmonitor.c                              | 21 ++++++++++++++-------
 read-cache.c                             |  3 ++-
 t/t1092-sparse-checkout-compatibility.sh |  8 ++++----
 3 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/fsmonitor.c b/fsmonitor.c
index 7b8cd3975b9..99b26576baa 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -58,6 +58,9 @@ int read_fsmonitor_extension(struct index_state *istate, const void *data,
 	uint64_t timestamp;
 	struct strbuf last_update = STRBUF_INIT;
 
+	if (istate->sparse_index)
+		return 0;
+
 	if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t))
 		return error("corrupt fsmonitor extension (too short)");
 
@@ -98,7 +101,8 @@ void fill_fsmonitor_bitmap(struct index_state *istate)
 {
 	unsigned int i, skipped = 0;
 
-	ensure_full_index(istate);
+	if (istate->sparse_index)
+		return;
 
 	istate->fsmonitor_dirty = ewah_new();
 	for (i = 0; i < istate->cache_nr; i++) {
@@ -161,11 +165,7 @@ static int query_fsmonitor(int version, const char *last_update, struct strbuf *
 
 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
 {
-	int pos;
-
-	ensure_full_index(istate);
-
-	pos = index_name_pos(istate, name, strlen(name));
+	int pos = index_name_pos(istate, name, strlen(name));
 
 	if (pos >= 0) {
 		struct cache_entry *ce = istate->cache[pos];
@@ -190,7 +190,8 @@ void refresh_fsmonitor(struct index_state *istate)
 	char *buf;
 	unsigned int i;
 
-	if (!core_fsmonitor || istate->fsmonitor_has_run_once)
+	if (!core_fsmonitor || istate->fsmonitor_has_run_once ||
+	    istate->sparse_index)
 		return;
 
 	hook_version = fsmonitor_hook_version();
@@ -300,6 +301,9 @@ void add_fsmonitor(struct index_state *istate)
 	unsigned int i;
 	struct strbuf last_update = STRBUF_INIT;
 
+	if (istate->sparse_index)
+		return;
+
 	if (!istate->fsmonitor_last_update) {
 		trace_printf_key(&trace_fsmonitor, "add fsmonitor");
 		istate->cache_changed |= FSMONITOR_CHANGED;
@@ -335,6 +339,9 @@ void tweak_fsmonitor(struct index_state *istate)
 	unsigned int i;
 	int fsmonitor_enabled = git_config_get_fsmonitor();
 
+	if (istate->sparse_index)
+		fsmonitor_enabled = 0;
+
 	if (istate->fsmonitor_dirty) {
 		if (fsmonitor_enabled) {
 			ensure_full_index(istate);
diff --git a/read-cache.c b/read-cache.c
index 8c974829497..96d9b95128a 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3017,7 +3017,8 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 		if (err)
 			return -1;
 	}
-	if (!strip_extensions && istate->fsmonitor_last_update) {
+	if (!strip_extensions && istate->fsmonitor_last_update &&
+	    !istate->sparse_index) {
 		struct strbuf sb = STRBUF_INIT;
 
 		write_fsmonitor_extension(&sb, istate);
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 2e8efe6ab37..1cdf33a4025 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -388,7 +388,7 @@ test_expect_success 'sparse-index is expanded and converted back' '
 	init_repos &&
 
 	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
-		git -C sparse-index -c core.fsmonitor="" reset --hard &&
+		git -C sparse-index reset --hard &&
 	test_region index convert_to_sparse trace2.txt &&
 	test_region index ensure_full_index trace2.txt
 '
@@ -398,19 +398,19 @@ test_expect_success 'sparse-index is not expanded' '
 
 	rm -f trace2.txt &&
 	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
-		git -C sparse-index -c core.fsmonitor="" status -uno &&
+		git -C sparse-index status -uno &&
 	test_region ! index ensure_full_index trace2.txt &&
 
 	rm trace2.txt &&
 	echo >>sparse-index/README.md &&
 	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
-		git -C sparse-index -c core.fsmonitor="" add -A &&
+		git -C sparse-index add -A &&
 	test_region ! index ensure_full_index trace2.txt &&
 
 	rm trace2.txt &&
 	echo >>sparse-index/extra.txt &&
 	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
-		git -C sparse-index -c core.fsmonitor="" add extra.txt &&
+		git -C sparse-index add extra.txt &&
 	test_region ! index ensure_full_index trace2.txt
 '
 

-- 
gitgitgadget
Previous: Elijah NewrenNext: Derrick Stolee via GitGitGadget
Message 48 of 61 in “[RFC] Sparse Index”
  1. 00/27 [RFC] Sparse IndexDerrick Stolee via GitGitGadget, Jan 25, 2021
  2. 02/27 sparse-index: implement ensure_full_index()Derrick Stolee via GitGitGadget, Jan 25, 2021
  3. Elijah NewrenJan 27, 2021
  4. Derrick StoleeJan 27, 2021
  5. Elijah NewrenJan 27, 2021
  6. Junio C HamanoJan 28, 2021
  7. 01/27 sparse-index: add guard to ensure full indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  8. 09/27 sparse-index: convert from full to sparseDerrick Stolee via GitGitGadget, Jan 25, 2021
  9. Elijah NewrenJan 27, 2021
  10. 08/27 sparse-checkout: hold pattern list in indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  11. Elijah NewrenJan 27, 2021
  12. Derrick StoleeJan 28, 2021
  13. 06/27 test-tool: don't force full indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  14. 12/27 sparse-index: check index conversion happensDerrick Stolee via GitGitGadget, Jan 25, 2021
  15. Elijah NewrenJan 27, 2021
  16. 15/27 [RFC-VERSION] *: ensure full indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  17. Elijah NewrenFeb 1, 2021
  18. Derrick StoleeFeb 1, 2021
  19. 26/27 pathspec: stop calling ensure_full_indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  20. Elijah NewrenFeb 1, 2021
  21. Derrick StoleeFeb 2, 2021
  22. 14/27 sparse-checkout: toggle sparse index from builtinDerrick Stolee via GitGitGadget, Jan 25, 2021
  23. Elijah NewrenJan 27, 2021
  24. Derrick StoleeJan 28, 2021
  25. 19/27 status: skip sparse-checkout percentage with sparse-indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  26. 04/27 test-read-cache: print cache entries with --tableDerrick Stolee via GitGitGadget, Jan 25, 2021
  27. Elijah NewrenJan 27, 2021
  28. 16/27 unpack-trees: make sparse awareDerrick Stolee via GitGitGadget, Jan 25, 2021
  29. Elijah NewrenFeb 1, 2021
  30. Derrick StoleeFeb 9, 2021
  31. 03/27 t1092: compare sparse-checkout to sparse-indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  32. Elijah NewrenJan 27, 2021
  33. Derrick StoleeJan 27, 2021
  34. Elijah NewrenJan 27, 2021
  35. 27/27 cache-tree: integrate with sparse directory entriesDerrick Stolee via GitGitGadget, Jan 25, 2021
  36. Elijah NewrenFeb 1, 2021
  37. Derrick StoleeFeb 2, 2021
  38. Elijah NewrenFeb 2, 2021
  39. 18/27 status: use sparse-index throughoutDerrick Stolee via GitGitGadget, Jan 25, 2021
  40. 22/27 add: allow operating on a sparse-only indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  41. Elijah NewrenFeb 1, 2021
  42. 20/27 sparse-index: expand_to_path() trivial implementationDerrick Stolee via GitGitGadget, Jan 25, 2021
  43. 21/27 sparse-index: expand_to_path no-op if path existsDerrick Stolee via GitGitGadget, Jan 25, 2021
  44. Elijah NewrenFeb 1, 2021
  45. 10/27 submodule: sparse-index should not collapse linksDerrick Stolee via GitGitGadget, Jan 25, 2021
  46. 17/27 dir.c: accept a directory as part of cone-mode patternsDerrick Stolee via GitGitGadget, Jan 25, 2021
  47. Elijah NewrenFeb 1, 2021
  48. 25/27 fsmonitor: disable if index is sparseDerrick Stolee via GitGitGadget, Jan 25, 2021
  49. 13/27 sparse-index: create extension for compatibilityDerrick Stolee via GitGitGadget, Jan 25, 2021
  50. Elijah NewrenJan 27, 2021
  51. 07/27 unpack-trees: ensure full indexDerrick Stolee via GitGitGadget, Jan 25, 2021
  52. Elijah NewrenJan 27, 2021
  53. 24/27 dir: use expand_to_path in add_patterns()Derrick Stolee via GitGitGadget, Jan 25, 2021
  54. Elijah NewrenFeb 1, 2021
  55. 05/27 test-tool: read-cache --table --no-statDerrick Stolee via GitGitGadget, Jan 25, 2021
  56. 11/27 unpack-trees: allow sparse directoriesDerrick Stolee via GitGitGadget, Jan 25, 2021
  57. Elijah NewrenJan 27, 2021
  58. 23/27 submodule: die_path_inside_submodule is sparse awareDerrick Stolee via GitGitGadget, Jan 25, 2021
  59. Junio C HamanoJan 25, 2021
  60. Derrick StoleeJan 25, 2021
  61. Elijah NewrenFeb 2, 2021

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.