From 56c6910028a0468761b0cd9ee5c0946ce637b586 Mon Sep 17 00:00:00 2001 From: Kevin Willford Date: Tue, 7 Jan 2020 19:04:28 +0000 Subject: fsmonitor: change last update timestamp on the index_state to opaque token Some file system monitors might not use or take a timestamp for processing and in the case of watchman could have race conditions with using a timestamp. Watchman uses something called a clockid that is used for race free queries to it. The clockid for watchman is simply a string. Change the fsmonitor_last_update from being a uint64_t to a char pointer so that any arbitrary data can be stored in it and passed back to the fsmonitor. Signed-off-by: Kevin Willford Signed-off-by: Junio C Hamano --- fsmonitor.c | 49 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 32 insertions(+), 17 deletions(-) (limited to 'fsmonitor.c') diff --git a/fsmonitor.c b/fsmonitor.c index 868cca01e2..9860587225 100644 --- a/fsmonitor.c +++ b/fsmonitor.c @@ -6,8 +6,9 @@ #include "run-command.h" #include "strbuf.h" -#define INDEX_EXTENSION_VERSION (1) -#define HOOK_INTERFACE_VERSION (1) +#define INDEX_EXTENSION_VERSION1 (1) +#define INDEX_EXTENSION_VERSION2 (2) +#define HOOK_INTERFACE_VERSION (1) struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR); @@ -32,17 +33,26 @@ int read_fsmonitor_extension(struct index_state *istate, const void *data, uint32_t ewah_size; struct ewah_bitmap *fsmonitor_dirty; int ret; + uint64_t timestamp; + struct strbuf last_update = STRBUF_INIT; - if (sz < sizeof(uint32_t) + sizeof(uint64_t) + sizeof(uint32_t)) + if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t)) return error("corrupt fsmonitor extension (too short)"); hdr_version = get_be32(index); index += sizeof(uint32_t); - if (hdr_version != INDEX_EXTENSION_VERSION) + if (hdr_version == INDEX_EXTENSION_VERSION1) { + timestamp = get_be64(index); + strbuf_addf(&last_update, "%"PRIu64"", timestamp); + index += sizeof(uint64_t); + } else if (hdr_version == INDEX_EXTENSION_VERSION2) { + strbuf_addstr(&last_update, index); + index += last_update.len + 1; + } else { return error("bad fsmonitor version %d", hdr_version); + } - istate->fsmonitor_last_update = get_be64(index); - index += sizeof(uint64_t); + istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); ewah_size = get_be32(index); index += sizeof(uint32_t); @@ -79,7 +89,6 @@ void fill_fsmonitor_bitmap(struct index_state *istate) void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) { uint32_t hdr_version; - uint64_t tm; uint32_t ewah_start; uint32_t ewah_size = 0; int fixup = 0; @@ -89,11 +98,12 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); - put_be32(&hdr_version, INDEX_EXTENSION_VERSION); + put_be32(&hdr_version, INDEX_EXTENSION_VERSION2); strbuf_add(sb, &hdr_version, sizeof(uint32_t)); - put_be64(&tm, istate->fsmonitor_last_update); - strbuf_add(sb, &tm, sizeof(uint64_t)); + strbuf_addstr(sb, istate->fsmonitor_last_update); + strbuf_addch(sb, 0); /* Want to keep a NUL */ + fixup = sb->len; strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */ @@ -110,9 +120,9 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) } /* - * Call the query-fsmonitor hook passing the time of the last saved results. + * Call the query-fsmonitor hook passing the last update token of the saved results. */ -static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *query_result) +static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result) { struct child_process cp = CHILD_PROCESS_INIT; @@ -121,7 +131,7 @@ static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *que argv_array_push(&cp.args, core_fsmonitor); argv_array_pushf(&cp.args, "%d", version); - argv_array_pushf(&cp.args, "%" PRIuMAX, (uintmax_t)last_update); + argv_array_pushf(&cp.args, "%s", last_update); cp.use_shell = 1; cp.dir = get_git_work_tree(); @@ -151,6 +161,7 @@ void refresh_fsmonitor(struct index_state *istate) int query_success = 0; size_t bol; /* beginning of line */ uint64_t last_update; + struct strbuf last_update_token = STRBUF_INIT; char *buf; unsigned int i; @@ -164,6 +175,7 @@ void refresh_fsmonitor(struct index_state *istate) * should be inclusive to ensure we don't miss potential changes. */ last_update = getnanotime(); + strbuf_addf(&last_update_token, "%"PRIu64"", last_update); /* * If we have a last update time, call query_fsmonitor for the set of @@ -217,18 +229,21 @@ void refresh_fsmonitor(struct index_state *istate) } strbuf_release(&query_result); - /* Now that we've updated istate, save the last_update time */ - istate->fsmonitor_last_update = last_update; + /* Now that we've updated istate, save the last_update_token */ + FREE_AND_NULL(istate->fsmonitor_last_update); + istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL); } void add_fsmonitor(struct index_state *istate) { unsigned int i; + struct strbuf last_update = STRBUF_INIT; if (!istate->fsmonitor_last_update) { trace_printf_key(&trace_fsmonitor, "add fsmonitor"); istate->cache_changed |= FSMONITOR_CHANGED; - istate->fsmonitor_last_update = getnanotime(); + strbuf_addf(&last_update, "%"PRIu64"", getnanotime()); + istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); /* reset the fsmonitor state */ for (i = 0; i < istate->cache_nr; i++) @@ -250,7 +265,7 @@ void remove_fsmonitor(struct index_state *istate) if (istate->fsmonitor_last_update) { trace_printf_key(&trace_fsmonitor, "remove fsmonitor"); istate->cache_changed |= FSMONITOR_CHANGED; - istate->fsmonitor_last_update = 0; + FREE_AND_NULL(istate->fsmonitor_last_update); } } -- cgit v1.3 From 8da2c57629a16e148b0f94282ac787c1503e4779 Mon Sep 17 00:00:00 2001 From: Kevin Willford Date: Tue, 7 Jan 2020 19:04:29 +0000 Subject: fsmonitor: handle version 2 of the hooks that will use opaque token Some file monitors like watchman will use something other than a timestamp to keep better track of what changes happen in between calls to query the fsmonitor. The clockid in watchman is a string. Now that the index is storing an opaque token for the last update the code needs to be updated to pass that opaque token to a verion 2 of the fsmonitor hook. Because there are repos that already have version 1 of the hook and we want them to continue to work when git is updated, we need to handle both version 1 and version 2 of the hook. In order to do that a config value is being added core.fsmonitorHookVersion to force what version of the hook should be used. When this is not set it will default to -1 and then the code will attempt to call version 2 of the hook first. If that fails it will fallback to trying version 1. Signed-off-by: Kevin Willford Signed-off-by: Junio C Hamano --- fsmonitor.c | 75 ++++++++++++++++++++++++++++++++++++++------- t/t7519-status-fsmonitor.sh | 7 ++++- t/t7519/fsmonitor-all | 1 - t/t7519/fsmonitor-watchman | 3 +- 4 files changed, 71 insertions(+), 15 deletions(-) (limited to 'fsmonitor.c') diff --git a/fsmonitor.c b/fsmonitor.c index 9860587225..932bd9012d 100644 --- a/fsmonitor.c +++ b/fsmonitor.c @@ -8,7 +8,8 @@ #define INDEX_EXTENSION_VERSION1 (1) #define INDEX_EXTENSION_VERSION2 (2) -#define HOOK_INTERFACE_VERSION (1) +#define HOOK_INTERFACE_VERSION1 (1) +#define HOOK_INTERFACE_VERSION2 (2) struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR); @@ -25,6 +26,22 @@ static void fsmonitor_ewah_callback(size_t pos, void *is) ce->ce_flags &= ~CE_FSMONITOR_VALID; } +static int fsmonitor_hook_version(void) +{ + int hook_version; + + if (git_config_get_int("core.fsmonitorhookversion", &hook_version)) + return -1; + + if (hook_version == HOOK_INTERFACE_VERSION1 || + hook_version == HOOK_INTERFACE_VERSION2) + return hook_version; + + warning("Invalid hook version '%i' in core.fsmonitorhookversion. " + "Must be 1 or 2.", hook_version); + return -1; +} + int read_fsmonitor_extension(struct index_state *istate, const void *data, unsigned long sz) { @@ -158,8 +175,8 @@ static void fsmonitor_refresh_callback(struct index_state *istate, const char *n void refresh_fsmonitor(struct index_state *istate) { struct strbuf query_result = STRBUF_INIT; - int query_success = 0; - size_t bol; /* beginning of line */ + int query_success = 0, hook_version = -1; + size_t bol = 0; /* beginning of line */ uint64_t last_update; struct strbuf last_update_token = STRBUF_INIT; char *buf; @@ -167,6 +184,9 @@ void refresh_fsmonitor(struct index_state *istate) if (!core_fsmonitor || istate->fsmonitor_has_run_once) return; + + hook_version = fsmonitor_hook_version(); + istate->fsmonitor_has_run_once = 1; trace_printf_key(&trace_fsmonitor, "refresh fsmonitor"); @@ -175,27 +195,60 @@ void refresh_fsmonitor(struct index_state *istate) * should be inclusive to ensure we don't miss potential changes. */ last_update = getnanotime(); - strbuf_addf(&last_update_token, "%"PRIu64"", last_update); + if (hook_version == HOOK_INTERFACE_VERSION1) + strbuf_addf(&last_update_token, "%"PRIu64"", last_update); /* - * If we have a last update time, call query_fsmonitor for the set of - * changes since that time, else assume everything is possibly dirty + * If we have a last update token, call query_fsmonitor for the set of + * changes since that token, else assume everything is possibly dirty * and check it all. */ if (istate->fsmonitor_last_update) { - query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION, - istate->fsmonitor_last_update, &query_result); + if (hook_version == -1 || hook_version == HOOK_INTERFACE_VERSION2) { + query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION2, + istate->fsmonitor_last_update, &query_result); + + if (query_success) { + if (hook_version < 0) + hook_version = HOOK_INTERFACE_VERSION2; + + /* + * First entry will be the last update token + * Need to use a char * variable because static + * analysis was suggesting to use strbuf_addbuf + * but we don't want to copy the entire strbuf + * only the the chars up to the first NUL + */ + buf = query_result.buf; + strbuf_addstr(&last_update_token, buf); + if (!last_update_token.len) { + warning("Empty last update token."); + query_success = 0; + } else { + bol = last_update_token.len + 1; + } + } else if (hook_version < 0) { + hook_version = HOOK_INTERFACE_VERSION1; + if (!last_update_token.len) + strbuf_addf(&last_update_token, "%"PRIu64"", last_update); + } + } + + if (hook_version == HOOK_INTERFACE_VERSION1) { + query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION1, + istate->fsmonitor_last_update, &query_result); + } + trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor); trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s", core_fsmonitor, query_success ? "success" : "failure"); } /* a fsmonitor process can return '/' to indicate all entries are invalid */ - if (query_success && query_result.buf[0] != '/') { + if (query_success && query_result.buf[bol] != '/') { /* Mark all entries returned by the monitor as dirty */ buf = query_result.buf; - bol = 0; - for (i = 0; i < query_result.len; i++) { + for (i = bol; i < query_result.len; i++) { if (buf[i] != '\0') continue; fsmonitor_refresh_callback(istate, buf + bol); diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh index cf0fda2d5a..fbfdcca000 100755 --- a/t/t7519-status-fsmonitor.sh +++ b/t/t7519-status-fsmonitor.sh @@ -32,11 +32,12 @@ write_integration_script () { echo "$0: exactly 2 arguments expected" exit 2 fi - if test "$1" != 1 + if test "$1" != 2 then echo "Unsupported core.fsmonitor hook version." >&2 exit 1 fi + printf "last_update_token\0" printf "untracked\0" printf "dir1/untracked\0" printf "dir2/untracked\0" @@ -107,6 +108,7 @@ EOF # test that "update-index --fsmonitor-valid" sets the fsmonitor valid bit test_expect_success 'update-index --fsmonitor-valid" sets the fsmonitor valid bit' ' write_script .git/hooks/fsmonitor-test<<-\EOF && + printf "last_update_token\0" EOF git update-index --fsmonitor && git update-index --fsmonitor-valid dir1/modified && @@ -167,6 +169,7 @@ EOF # test that newly added files are marked valid test_expect_success 'newly added files are marked valid' ' write_script .git/hooks/fsmonitor-test<<-\EOF && + printf "last_update_token\0" EOF git add new && git add dir1/new && @@ -207,6 +210,7 @@ EOF # test that *only* files returned by the integration script get flagged as invalid test_expect_success '*only* files returned by the integration script get flagged as invalid' ' write_script .git/hooks/fsmonitor-test<<-\EOF && + printf "last_update_token\0" printf "dir1/modified\0" EOF clean_repo && @@ -276,6 +280,7 @@ do # (if enabled) files unless it is told about them. test_expect_success "status doesn't detect unreported modifications" ' write_script .git/hooks/fsmonitor-test<<-\EOF && + printf "last_update_token\0" :>marker EOF clean_repo && diff --git a/t/t7519/fsmonitor-all b/t/t7519/fsmonitor-all index 691bc94dc2..94ab66bd3d 100755 --- a/t/t7519/fsmonitor-all +++ b/t/t7519/fsmonitor-all @@ -17,7 +17,6 @@ fi if test "$1" != 1 then - echo "Unsupported core.fsmonitor hook version." >&2 exit 1 fi diff --git a/t/t7519/fsmonitor-watchman b/t/t7519/fsmonitor-watchman index d8e7a1e5ba..264b9daf83 100755 --- a/t/t7519/fsmonitor-watchman +++ b/t/t7519/fsmonitor-watchman @@ -26,8 +26,7 @@ if ($version == 1) { # subtract one second to make sure watchman will return all changes $time = int ($time / 1000000000) - 1; } else { - die "Unsupported query-fsmonitor hook version '$version'.\n" . - "Falling back to scanning...\n"; + exit 1; } my $git_work_tree; -- cgit v1.3