diff options
| -rw-r--r-- | Documentation/config/core.txt | 58 | ||||
| -rw-r--r-- | Makefile | 6 | ||||
| -rw-r--r-- | builtin/fast-import.c | 2 | ||||
| -rw-r--r-- | builtin/index-pack.c | 4 | ||||
| -rw-r--r-- | builtin/pack-objects.c | 24 | ||||
| -rw-r--r-- | bulk-checkin.c | 5 | ||||
| -rw-r--r-- | cache.h | 48 | ||||
| -rw-r--r-- | commit-graph.c | 3 | ||||
| -rw-r--r-- | compat/mingw.h | 3 | ||||
| -rw-r--r-- | compat/win32/flush.c | 28 | ||||
| -rw-r--r-- | compat/winansi.c | 5 | ||||
| -rw-r--r-- | config.c | 94 | ||||
| -rw-r--r-- | config.mak.uname | 3 | ||||
| -rw-r--r-- | configure.ac | 8 | ||||
| -rw-r--r-- | contrib/buildsystems/CMakeLists.txt | 16 | ||||
| -rw-r--r-- | csum-file.c | 5 | ||||
| -rw-r--r-- | csum-file.h | 3 | ||||
| -rw-r--r-- | environment.c | 4 | ||||
| -rw-r--r-- | git-compat-util.h | 30 | ||||
| -rw-r--r-- | midx.c | 3 | ||||
| -rw-r--r-- | object-file.c | 13 | ||||
| -rw-r--r-- | pack-bitmap-write.c | 3 | ||||
| -rw-r--r-- | pack-write.c | 13 | ||||
| -rw-r--r-- | read-cache.c | 19 | ||||
| -rw-r--r-- | wrapper.c | 71 | ||||
| -rw-r--r-- | write-or-die.c | 33 |
26 files changed, 444 insertions, 60 deletions
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index c04f62a54a..9a3ad71e9e 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt @@ -547,13 +547,63 @@ core.whitespace:: is relevant for `indent-with-non-tab` and when Git fixes `tab-in-indent` errors. The default tab width is 8. Allowed values are 1 to 63. +core.fsync:: + A comma-separated list of components of the repository that + should be hardened via the core.fsyncMethod when created or + modified. You can disable hardening of any component by + prefixing it with a '-'. Items that are not hardened may be + lost in the event of an unclean system shutdown. Unless you + have special requirements, it is recommended that you leave + this option empty or pick one of `committed`, `added`, + or `all`. ++ +When this configuration is encountered, the set of components starts with +the platform default value, disabled components are removed, and additional +components are added. `none` resets the state so that the platform default +is ignored. ++ +The empty string resets the fsync configuration to the platform +default. The default on most platforms is equivalent to +`core.fsync=committed,-loose-object`, which has good performance, +but risks losing recent work in the event of an unclean system shutdown. ++ +* `none` clears the set of fsynced components. +* `loose-object` hardens objects added to the repo in loose-object form. +* `pack` hardens objects added to the repo in packfile form. +* `pack-metadata` hardens packfile bitmaps and indexes. +* `commit-graph` hardens the commit graph file. +* `index` hardens the index when it is modified. +* `objects` is an aggregate option that is equivalent to + `loose-object,pack`. +* `derived-metadata` is an aggregate option that is equivalent to + `pack-metadata,commit-graph`. +* `committed` is an aggregate option that is currently equivalent to + `objects`. This mode sacrifices some performance to ensure that work + that is committed to the repository with `git commit` or similar commands + is hardened. +* `added` is an aggregate option that is currently equivalent to + `committed,index`. This mode sacrifices additional performance to + ensure that the results of commands like `git add` and similar operations + are hardened. +* `all` is an aggregate option that syncs all individual components above. + +core.fsyncMethod:: + A value indicating the strategy Git will use to harden repository data + using fsync and related primitives. ++ +* `fsync` uses the fsync() system call or platform equivalents. +* `writeout-only` issues pagecache writeback requests, but depending on the + filesystem and storage hardware, data added to the repository may not be + durable in the event of a system crash. This is the default mode on macOS. + core.fsyncObjectFiles:: This boolean will enable 'fsync()' when writing object files. + This setting is deprecated. Use core.fsync instead. + -This is a total waste of time and effort on a filesystem that orders -data writes properly, but can be useful for filesystems that do not use -journalling (traditional UNIX filesystems) or that only journal metadata -and not file contents (OS X's HFS+, or Linux ext3 with "data=writeback"). +This setting affects data added to the Git repository in loose-object +form. When set to true, Git will issue an fsync or similar system call +to flush caches so that loose-objects remain consistent in the face +of a unclean system shutdown. core.preloadIndex:: Enable parallel index preload for operations like 'git diff' @@ -411,6 +411,8 @@ all:: # # Define HAVE_CLOCK_MONOTONIC if your platform has CLOCK_MONOTONIC. # +# Define HAVE_SYNC_FILE_RANGE if your platform has sync_file_range. +# # Define NEEDS_LIBRT if your platform requires linking with librt (glibc version # before 2.17) for clock_gettime and CLOCK_MONOTONIC. # @@ -1897,6 +1899,10 @@ ifdef HAVE_CLOCK_MONOTONIC BASIC_CFLAGS += -DHAVE_CLOCK_MONOTONIC endif +ifdef HAVE_SYNC_FILE_RANGE + BASIC_CFLAGS += -DHAVE_SYNC_FILE_RANGE +endif + ifdef NEEDS_LIBRT EXTLIBS += -lrt endif diff --git a/builtin/fast-import.c b/builtin/fast-import.c index b7105fcad9..f2c036a895 100644 --- a/builtin/fast-import.c +++ b/builtin/fast-import.c @@ -865,7 +865,7 @@ static void end_packfile(void) struct tag *t; close_pack_windows(pack_data); - finalize_hashfile(pack_file, cur_pack_oid.hash, 0); + finalize_hashfile(pack_file, cur_pack_oid.hash, FSYNC_COMPONENT_PACK, 0); fixup_pack_header_footer(pack_data->pack_fd, pack_data->hash, pack_data->pack_name, object_count, cur_pack_oid.hash, pack_size); diff --git a/builtin/index-pack.c b/builtin/index-pack.c index c45273de3b..c5f12f14df 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -1290,7 +1290,7 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha nr_objects - nr_objects_initial); stop_progress_msg(&progress, msg.buf); strbuf_release(&msg); - finalize_hashfile(f, tail_hash, 0); + finalize_hashfile(f, tail_hash, FSYNC_COMPONENT_PACK, 0); hashcpy(read_hash, pack_hash); fixup_pack_header_footer(output_fd, pack_hash, curr_pack, nr_objects, @@ -1512,7 +1512,7 @@ static void final(const char *final_pack_name, const char *curr_pack_name, if (!from_stdin) { close(input_fd); } else { - fsync_or_die(output_fd, curr_pack_name); + fsync_component_or_die(FSYNC_COMPONENT_PACK, output_fd, curr_pack_name); err = close(output_fd); if (err) die_errno(_("error while closing pack file")); diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index 178e611f09..c14fee8e99 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -1199,16 +1199,26 @@ static void write_pack_file(void) display_progress(progress_state, written); } - /* - * Did we write the wrong # entries in the header? - * If so, rewrite it like in fast-import - */ if (pack_to_stdout) { - finalize_hashfile(f, hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE); + /* + * We never fsync when writing to stdout since we may + * not be writing to an actual pack file. For instance, + * the upload-pack code passes a pipe here. Calling + * fsync on a pipe results in unnecessary + * synchronization with the reader on some platforms. + */ + finalize_hashfile(f, hash, FSYNC_COMPONENT_NONE, + CSUM_HASH_IN_STREAM | CSUM_CLOSE); } else if (nr_written == nr_remaining) { - finalize_hashfile(f, hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE); + finalize_hashfile(f, hash, FSYNC_COMPONENT_PACK, + CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE); } else { - int fd = finalize_hashfile(f, hash, 0); + /* + * If we wrote the wrong number of entries in the + * header, rewrite it like in fast-import. + */ + + int fd = finalize_hashfile(f, hash, FSYNC_COMPONENT_PACK, 0); fixup_pack_header_footer(fd, hash, pack_tmp_name, nr_written, hash, offset); close(fd); diff --git a/bulk-checkin.c b/bulk-checkin.c index 8785b2ac80..a2cf9dcbc8 100644 --- a/bulk-checkin.c +++ b/bulk-checkin.c @@ -53,9 +53,10 @@ static void finish_bulk_checkin(struct bulk_checkin_state *state) unlink(state->pack_tmp_name); goto clear_exit; } else if (state->nr_written == 1) { - finalize_hashfile(state->f, hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE); + finalize_hashfile(state->f, hash, FSYNC_COMPONENT_PACK, + CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE); } else { - int fd = finalize_hashfile(state->f, hash, 0); + int fd = finalize_hashfile(state->f, hash, FSYNC_COMPONENT_PACK, 0); fixup_pack_header_footer(fd, hash, state->pack_tmp_name, state->nr_written, hash, state->offset); @@ -993,8 +993,54 @@ void reset_shared_repository(void); extern int read_replace_refs; extern char *git_replace_ref_base; +/* + * These values are used to help identify parts of a repository to fsync. + * FSYNC_COMPONENT_NONE identifies data that will not be a persistent part of the + * repository and so shouldn't be fsynced. + */ +enum fsync_component { + FSYNC_COMPONENT_NONE, + FSYNC_COMPONENT_LOOSE_OBJECT = 1 << 0, + FSYNC_COMPONENT_PACK = 1 << 1, + FSYNC_COMPONENT_PACK_METADATA = 1 << 2, + FSYNC_COMPONENT_COMMIT_GRAPH = 1 << 3, + FSYNC_COMPONENT_INDEX = 1 << 4, +}; + +#define FSYNC_COMPONENTS_OBJECTS (FSYNC_COMPONENT_LOOSE_OBJECT | \ + FSYNC_COMPONENT_PACK) + +#define FSYNC_COMPONENTS_DERIVED_METADATA (FSYNC_COMPONENT_PACK_METADATA | \ + FSYNC_COMPONENT_COMMIT_GRAPH) + +#define FSYNC_COMPONENTS_DEFAULT (FSYNC_COMPONENTS_OBJECTS | \ + FSYNC_COMPONENTS_DERIVED_METADATA | \ + ~FSYNC_COMPONENT_LOOSE_OBJECT) + +#define FSYNC_COMPONENTS_COMMITTED (FSYNC_COMPONENTS_OBJECTS) + +#define FSYNC_COMPONENTS_ADDED (FSYNC_COMPONENTS_COMMITTED | \ + FSYNC_COMPONENT_INDEX) + +#define FSYNC_COMPONENTS_ALL (FSYNC_COMPONENT_LOOSE_OBJECT | \ + FSYNC_COMPONENT_PACK | \ + FSYNC_COMPONENT_PACK_METADATA | \ + FSYNC_COMPONENT_COMMIT_GRAPH | \ + FSYNC_COMPONENT_INDEX) + +/* + * A bitmask indicating which components of the repo should be fsynced. + */ +extern enum fsync_component fsync_components; extern int fsync_object_files; extern int use_fsync; + +enum fsync_method { + FSYNC_METHOD_FSYNC, + FSYNC_METHOD_WRITEOUT_ONLY +}; + +extern enum fsync_method fsync_method; extern int core_preload_index; extern int precomposed_unicode; extern int protect_hfs; @@ -1701,6 +1747,8 @@ int copy_file_with_time(const char *dst, const char *src, int mode); void write_or_die(int fd, const void *buf, size_t count); void fsync_or_die(int fd, const char *); +int fsync_component(enum fsync_component component, int fd); +void fsync_component_or_die(enum fsync_component component, int fd, const char *msg); ssize_t read_in_full(int fd, void *buf, size_t count); ssize_t write_in_full(int fd, const void *buf, size_t count); diff --git a/commit-graph.c b/commit-graph.c index 265c010122..64897f57d9 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -1942,7 +1942,8 @@ static int write_commit_graph_file(struct write_commit_graph_context *ctx) } close_commit_graph(ctx->r->objects); - finalize_hashfile(f, file_hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC); + finalize_hashfile(f, file_hash, FSYNC_COMPONENT_COMMIT_GRAPH, + CSUM_HASH_IN_STREAM | CSUM_FSYNC); free_chunkfile(cf); if (ctx->split) { diff --git a/compat/mingw.h b/compat/mingw.h index c9a52ad64a..6074a3d3ce 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -329,6 +329,9 @@ int mingw_getpagesize(void); #define getpagesize mingw_getpagesize #endif +int win32_fsync_no_flush(int fd); +#define fsync_no_flush win32_fsync_no_flush + struct rlimit { unsigned int rlim_cur; }; diff --git a/compat/win32/flush.c b/compat/win32/flush.c new file mode 100644 index 0000000000..291f90ea94 --- /dev/null +++ b/compat/win32/flush.c @@ -0,0 +1,28 @@ +#include "git-compat-util.h" +#include <winternl.h> +#include "lazyload.h" + +int win32_fsync_no_flush(int fd) +{ + IO_STATUS_BLOCK io_status; + +#define FLUSH_FLAGS_FILE_DATA_ONLY 1 + + DECLARE_PROC_ADDR(ntdll.dll, NTSTATUS, NTAPI, NtFlushBuffersFileEx, + HANDLE FileHandle, ULONG Flags, PVOID Parameters, ULONG ParameterSize, + PIO_STATUS_BLOCK IoStatusBlock); + + if (!INIT_PROC_ADDR(NtFlushBuffersFileEx)) { + errno = ENOSYS; + return -1; + } + + memset(&io_status, 0, sizeof(io_status)); + if (NtFlushBuffersFileEx((HANDLE)_get_osfhandle(fd), FLUSH_FLAGS_FILE_DATA_ONLY, + NULL, 0, &io_status)) { + errno = EINVAL; + return -1; + } + + return 0; +} diff --git a/compat/winansi.c b/compat/winansi.c index 936a80a5f0..3abe8dd5a2 100644 --- a/compat/winansi.c +++ b/compat/winansi.c @@ -4,11 +4,6 @@ #undef NOGDI -/* - * Including the appropriate header file for RtlGenRandom causes MSVC to see a - * redefinition of types in an incompatible way when including headers below. - */ -#undef HAVE_RTLGENRANDOM #include "../git-compat-util.h" #include <wingdi.h> #include <winreg.h> @@ -1323,6 +1323,79 @@ static int git_parse_maybe_bool_text(const char *value) return -1; } +static const struct fsync_component_name { + const char *name; + enum fsync_component component_bits; +} fsync_component_names[] = { + { "loose-object", FSYNC_COMPONENT_LOOSE_OBJECT }, + { "pack", FSYNC_COMPONENT_PACK }, + { "pack-metadata", FSYNC_COMPONENT_PACK_METADATA }, + { "commit-graph", FSYNC_COMPONENT_COMMIT_GRAPH }, + { "index", FSYNC_COMPONENT_INDEX }, + { "objects", FSYNC_COMPONENTS_OBJECTS }, + { "derived-metadata", FSYNC_COMPONENTS_DERIVED_METADATA }, + { "committed", FSYNC_COMPONENTS_COMMITTED }, + { "added", FSYNC_COMPONENTS_ADDED }, + { "all", FSYNC_COMPONENTS_ALL }, +}; + +static enum fsync_component parse_fsync_components(const char *var, const char *string) +{ + enum fsync_component current = FSYNC_COMPONENTS_DEFAULT; + enum fsync_component positive = 0, negative = 0; + + while (string) { + int i; + size_t len; + const char *ep; + int negated = 0; + int found = 0; + + string = string + strspn(string, ", \t\n\r"); + ep = strchrnul(string, ','); + len = ep - string; + if (!strcmp(string, "none")) { + current = FSYNC_COMPONENT_NONE; + goto next_name; + } + + if (*string == '-') { + negated = 1; + string++; + len--; + if (!len) + warning(_("invalid value for variable %s"), var); + } + + if (!len) + break; + + for (i = 0; i < ARRAY_SIZE(fsync_component_names); ++i) { + const struct fsync_component_name *n = &fsync_component_names[i]; + + if (strncmp(n->name, string, len)) + continue; + + found = 1; + if (negated) + negative |= n->component_bits; + else + positive |= n->component_bits; + } + + if (!found) { + char *component = xstrndup(string, len); + warning(_("ignoring unknown core.fsync component '%s'"), component); + free(component); + } + +next_name: + string = ep; + } + + return (current & ~negative) | positive; +} + int git_parse_maybe_bool(const char *value) { int v = git_parse_maybe_bool_text(value); @@ -1600,7 +1673,28 @@ static int git_default_core_config(const char *var, const char *value, void *cb) return 0; } + if (!strcmp(var, "core.fsync")) { + if (!value) + return config_error_nonbool(var); + fsync_components = parse_fsync_components(var, value); + return 0; + } + + if (!strcmp(var, "core.fsyncmethod")) { + if (!value) + return config_error_nonbool(var); + if (!strcmp(value, "fsync")) + fsync_method = FSYNC_METHOD_FSYNC; + else if (!strcmp(value, "writeout-only")) + fsync_method = FSYNC_METHOD_WRITEOUT_ONLY; + else + warning(_("ignoring unknown core.fsyncMethod value '%s'"), value); + + } + if (!strcmp(var, "core.fsyncobjectfiles")) { + if (fsync_object_files < 0) + warning(_("core.fsyncobjectfiles is deprecated; use core.fsync instead")); fsync_object_files = git_config_bool(var, value); return 0; } diff --git a/config.mak.uname b/config.mak.uname index 4352ea39e9..404fff5dd0 100644 --- a/config.mak.uname +++ b/config.mak.uname @@ -57,6 +57,7 @@ ifeq ($(uname_S),Linux) HAVE_CLOCK_MONOTONIC = YesPlease # -lrt is needed for clock_gettime on glibc <= 2.16 NEEDS_LIBRT = YesPlease + HAVE_SYNC_FILE_RANGE = YesPlease HAVE_GETDELIM = YesPlease FREAD_READS_DIRECTORIES = UnfortunatelyYes BASIC_CFLAGS += -DHAVE_SYSINFO @@ -463,6 +464,7 @@ endif CFLAGS = BASIC_CFLAGS = -nologo -I. -Icompat/vcbuild/include -DWIN32 -D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE COMPAT_OBJS = compat/msvc.o compat/winansi.o \ + compat/win32/flush.o \ compat/win32/path-utils.o \ compat/win32/pthread.o compat/win32/syslog.o \ compat/win32/trace2_win32_process_info.o \ @@ -640,6 +642,7 @@ ifeq ($(uname_S),MINGW) COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\" COMPAT_OBJS += compat/mingw.o compat/winansi.o \ compat/win32/trace2_win32_process_info.o \ + compat/win32/flush.o \ compat/win32/path-utils.o \ compat/win32/pthread.o compat/win32/syslog.o \ compat/win32/dirent.o diff --git a/configure.ac b/configure.ac index 5ee25ec95c..6bd6bef1c4 100644 --- a/configure.ac +++ b/configure.ac @@ -1082,6 +1082,14 @@ AC_COMPILE_IFELSE([CLOCK_MONOTONIC_SRC], [AC_MSG_RESULT([no]) HAVE_CLOCK_MONOTONIC=]) GIT_CONF_SUBST([HAVE_CLOCK_MONOTONIC]) + +# +# Define HAVE_SYNC_FILE_RANGE=YesPlease if sync_file_range is available. +GIT_CHECK_FUNC(sync_file_range, + [HAVE_SYNC_FILE_RANGE=YesPlease], + [HAVE_SYNC_FILE_RANGE]) +GIT_CONF_SUBST([HAVE_SYNC_FILE_RANGE]) + # # Define NO_SETITIMER if you don't have setitimer. GIT_CHECK_FUNC(setitimer, diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt index e44232f85d..3a9e624166 100644 --- a/contrib/buildsystems/CMakeLists.txt +++ b/contrib/buildsystems/CMakeLists.txt @@ -261,10 +261,18 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Windows") NOGDI OBJECT_CREATION_MODE=1 __USE_MINGW_ANSI_STDIO=0 USE_NED_ALLOCATOR OVERRIDE_STRDUP MMAP_PREVENTS_DELETE USE_WIN32_MMAP UNICODE _UNICODE HAVE_WPGMPTR ENSURE_MSYSTEM_IS_SET HAVE_RTLGENRANDOM) - list(APPEND compat_SOURCES compat/mingw.c compat/winansi.c compat/win32/path-utils.c - compat/win32/pthread.c compat/win32mmap.c compat/win32/syslog.c - compat/win32/trace2_win32_process_info.c compat/win32/dirent.c - compat/nedmalloc/nedmalloc.c compat/strdup.c) + list(APPEND compat_SOURCES + compat/mingw.c + compat/winansi.c + compat/win32/flush.c + compat/win32/path-utils.c + compat/win32/pthread.c + compat/win32mmap.c + compat/win32/syslog.c + compat/win32/trace2_win32_process_info.c + compat/win32/dirent.c + compat/nedmalloc/nedmalloc.c + compat/strdup.c) set(NO_UNIX_SOCKETS 1) elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux") diff --git a/csum-file.c b/csum-file.c index 26e8a6df44..59ef3398ca 100644 --- a/csum-file.c +++ b/csum-file.c @@ -58,7 +58,8 @@ static void free_hashfile(struct hashfile *f) free(f); } -int finalize_hashfile(struct hashfile *f, unsigned char *result, unsigned int flags) +int finalize_hashfile(struct hashfile *f, unsigned char *result, + enum fsync_component component, unsigned int flags) { int fd; @@ -69,7 +70,7 @@ int finalize_hashfile(struct hashfile *f, unsigned char *result, unsigned int fl if (flags & CSUM_HASH_IN_STREAM) flush(f, f->buffer, the_hash_algo->rawsz); if (flags & CSUM_FSYNC) - fsync_or_die(f->fd, f->name); + fsync_component_or_die(component, f->fd, f->name); if (flags & CSUM_CLOSE) { if (close(f->fd)) die_errno("%s: sha1 file error on close", f->name); diff --git a/csum-file.h b/csum-file.h index 291215b34e..0d29f528fb 100644 --- a/csum-file.h +++ b/csum-file.h @@ -1,6 +1,7 @@ #ifndef CSUM_FILE_H #define CSUM_FILE_H +#include "cache.h" #include "hash.h" struct progress; @@ -38,7 +39,7 @@ int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *); struct hashfile *hashfd(int fd, const char *name); struct hashfile *hashfd_check(const char *name); struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp); -int finalize_hashfile(struct hashfile *, unsigned char *, unsigned int); +int finalize_hashfile(struct hashfile *, unsigned char *, enum fsync_component, unsigned int); void hashwrite(struct hashfile *, const void *, unsigned int); void hashflush(struct hashfile *f); void crc32_begin(struct hashfile *); diff --git a/environment.c b/environment.c index fb55bf6129..f27e235548 100644 --- a/environment.c +++ b/environment.c @@ -42,8 +42,10 @@ const char *git_attributes_file; const char *git_hooks_path; int zlib_compression_level = Z_BEST_SPEED; int pack_compression_level = Z_DEFAULT_COMPRESSION; -int fsync_object_files; +int fsync_object_files = -1; int use_fsync = -1; +enum fsync_method fsync_method = FSYNC_METHOD_DEFAULT; +enum fsync_component fsync_components = FSYNC_COMPONENTS_DEFAULT; size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE; size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT; size_t delta_base_cache_limit = 96 * 1024 * 1024; diff --git a/git-compat-util.h b/git-compat-util.h index e50e2fafae..0892e209a2 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -197,12 +197,6 @@ #endif #include <windows.h> #define GIT_WINDOWS_NATIVE -#ifdef HAVE_RTLGENRANDOM -/* This is required to get access to RtlGenRandom. */ -#define SystemFunction036 NTAPI SystemFunction036 -#include <NTSecAPI.h> -#undef SystemFunction036 -#endif #endif #include <unistd.h> @@ -1263,6 +1257,30 @@ __attribute__((format (printf, 3, 4))) NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...); #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__) +#ifdef __APPLE__ +#define FSYNC_METHOD_DEFAULT FSYNC_METHOD_WRITEOUT_ONLY +#else +#define FSYNC_METHOD_DEFAULT FSYNC_METHOD_FSYNC +#endif + +enum fsync_action { + FSYNC_WRITEOUT_ONLY, + FSYNC_HARDWARE_FLUSH +}; + +/* + * Issues an fsync against the specified file according to the specified mode. + * + * FSYNC_WRITEOUT_ONLY attempts to use interfaces available on some operating + * systems to flush the OS cache without issuing a flush command to the storage + * controller. If those interfaces are unavailable, the function fails with + * ENOSYS. + * + * FSYNC_HARDWARE_FLUSH does an OS writeout and hardware flush to ensure that + * changes are durable. It is not expected to fail. + */ +int git_fsync(int fd, enum fsync_action action); + /* * Preserves errno, prints a message, but gives no warning for ENOENT. * Returns 0 on success, which includes trying to unlink an object that does @@ -1438,7 +1438,8 @@ static int write_midx_internal(const char *object_dir, write_midx_header(f, get_num_chunks(cf), ctx.nr - dropped_packs); write_chunkfile(cf, &ctx); - finalize_hashfile(f, midx_hash, CSUM_FSYNC | CSUM_HASH_IN_STREAM); + finalize_hashfile(f, midx_hash, FSYNC_COMPONENT_PACK_METADATA, + CSUM_FSYNC | CSUM_HASH_IN_STREAM); free_chunkfile(cf); if (flags & MIDX_WRITE_REV_INDEX && diff --git a/object-file.c b/object-file.c index 03bd6a3baf..e3f0bf27ff 100644 --- a/object-file.c +++ b/object-file.c @@ -1849,11 +1849,16 @@ int hash_object_file(const struct git_hash_algo *algo, const void *buf, /* Finalize a file on disk, and close it. */ static void close_loose_object(int fd) { - if (!the_repository->objects->odb->will_destroy) { - if (fsync_object_files) - fsync_or_die(fd, "loose object file"); - } + if (the_repository->objects->odb->will_destroy) + goto out; + if (fsync_object_files > 0) + fsync_or_die(fd, "loose object file"); + else + fsync_component_or_die(FSYNC_COMPONENT_LOOSE_OBJECT, fd, + "loose object file"); + +out: if (close(fd) != 0) die_errno(_("error when closing loose object file")); } diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c index cab3eaa2ac..cf681547f2 100644 --- a/pack-bitmap-write.c +++ b/pack-bitmap-write.c @@ -719,7 +719,8 @@ void bitmap_writer_finish(struct pack_idx_entry **index, if (options & BITMAP_OPT_HASH_CACHE) write_hash_cache(f, index, index_nr); - finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE); + finalize_hashfile(f, NULL, FSYNC_COMPONENT_PACK_METADATA, + CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE); if (adjust_shared_perm(tmp_file.buf)) die_errno("unable to make temporary bitmap file readable"); diff --git a/pack-write.c b/pack-write.c index a5846f3a34..51812cb129 100644 --- a/pack-write.c +++ b/pack-write.c @@ -159,9 +159,9 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec } hashwrite(f, sha1, the_hash_algo->rawsz); - finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_CLOSE | - ((opts->flags & WRITE_IDX_VERIFY) - ? 0 : CSUM_FSYNC)); + finalize_hashfile(f, NULL, FSYNC_COMPONENT_PACK_METADATA, + CSUM_HASH_IN_STREAM | CSUM_CLOSE | + ((opts->flags & WRITE_IDX_VERIFY) ? 0 : CSUM_FSYNC)); return index_name; } @@ -281,8 +281,9 @@ const char *write_rev_file_order(const char *rev_name, if (rev_name && adjust_shared_perm(rev_name) < 0) die(_("failed to make %s readable"), rev_name); - finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_CLOSE | - ((flags & WRITE_IDX_VERIFY) ? 0 : CSUM_FSYNC)); + finalize_hashfile(f, NULL, FSYNC_COMPONENT_PACK_METADATA, + CSUM_HASH_IN_STREAM | CSUM_CLOSE | + ((flags & WRITE_IDX_VERIFY) ? 0 : CSUM_FSYNC)); return rev_name; } @@ -390,7 +391,7 @@ void fixup_pack_header_footer(int pack_fd, the_hash_algo->final_fn(partial_pack_hash, &old_hash_ctx); the_hash_algo->final_fn(new_pack_hash, &new_hash_ctx); write_or_die(pack_fd, new_pack_hash, the_hash_algo->rawsz); - fsync_or_die(pack_fd, pack_name); + fsync_component_or_die(FSYNC_COMPONENT_PACK, pack_fd, pack_name); } char *index_pack_lockfile(int ip_out, int *is_well_formed) diff --git a/read-cache.c b/read-cache.c index 79b9b99ebf..7683b67925 100644 --- a/read-cache.c +++ b/read-cache.c @@ -2842,7 +2842,7 @@ static int record_ieot(void) * rely on it. */ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, - int strip_extensions) + int strip_extensions, unsigned flags) { uint64_t start = getnanotime(); struct hashfile *f; @@ -2856,6 +2856,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; int drop_cache_tree = istate->drop_cache_tree; off_t offset; + int csum_fsync_flag; int ieot_entries = 1; struct index_entry_offset_table *ieot = NULL; int nr, nr_threads; @@ -3089,7 +3090,13 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, return -1; } - finalize_hashfile(f, istate->oid.hash, CSUM_HASH_IN_STREAM); + csum_fsync_flag = 0; + if (!alternate_index_output && (flags & COMMIT_LOCK)) + csum_fsync_flag = CSUM_FSYNC; + + finalize_hashfile(f, istate->oid.hash, FSYNC_COMPONENT_INDEX, + CSUM_HASH_IN_STREAM | csum_fsync_flag); + if (close_tempfile_gently(tempfile)) { error(_("could not close '%s'"), get_tempfile_path(tempfile)); return -1; @@ -3144,7 +3151,7 @@ static int do_write_locked_index(struct index_state *istate, struct lock_file *l */ trace2_region_enter_printf("index", "do_write_index", the_repository, "%s", get_lock_file_path(lock)); - ret = do_write_index(istate, lock->tempfile, 0); + ret = do_write_index(istate, lock->tempfile, 0, flags); trace2_region_leave_printf("index", "do_write_index", the_repository, "%s", get_lock_file_path(lock)); @@ -3238,7 +3245,7 @@ static int clean_shared_index_files(const char *current_hex) } static int write_shared_index(struct index_state *istate, - struct tempfile **temp) + struct tempfile **temp, unsigned flags) { struct split_index *si = istate->split_index; int ret, was_full = !istate->sparse_index; @@ -3248,7 +3255,7 @@ static int write_shared_index(struct index_state *istate, trace2_region_enter_printf("index", "shared/do_write_index", the_repository, "%s", get_tempfile_path(*temp)); - ret = do_write_index(si->base, *temp, 1); + ret = do_write_index(si->base, *temp, 1, flags); trace2_region_leave_printf("index", "shared/do_write_index", the_repository, "%s", get_tempfile_path(*temp)); @@ -3357,7 +3364,7 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock, ret = do_write_locked_index(istate, lock, flags); goto out; } - ret = write_shared_index(istate, &temp); + ret = write_shared_index(istate, &temp, flags); saved_errno = errno; if (is_tempfile_active(temp)) @@ -4,6 +4,13 @@ #include "cache.h" #include "config.h" +#ifdef HAVE_RTLGENRANDOM +/* This is required to get access to RtlGenRandom. */ +#define SystemFunction036 NTAPI SystemFunction036 +#include <NTSecAPI.h> +#undef SystemFunction036 +#endif + static int memory_limit_check(size_t size, int gentle) { static size_t limit = 0; @@ -539,6 +546,70 @@ int xmkstemp_mode(char *filename_template, int mode) return fd; } +/* + * Some platforms return EINTR from fsync. Since fsync is invoked in some + * cases by a wrapper that dies on failure, do not expose EINTR to callers. + */ +static int fsync_loop(int fd) +{ + int err; + + do { + err = fsync(fd); + } while (err < 0 && errno == EINTR); + return err; +} + +int git_fsync(int fd, enum fsync_action action) +{ + switch (action) { + case FSYNC_WRITEOUT_ONLY: + +#ifdef __APPLE__ + /* + * On macOS, fsync just causes filesystem cache writeback but + * does not flush hardware caches. + */ + return fsync_loop(fd); +#endif + +#ifdef HAVE_SYNC_FILE_RANGE + /* + * On linux 2.6.17 and above, sync_file_range is the way to + * issue a writeback without a hardware flush. An offset of + * 0 and size of 0 indicates writeout of the entire file and the + * wait flags ensure that all dirty data is written to the disk + * (potentially in a disk-side cache) before we continue. + */ + + return sync_file_range(fd, 0, 0, SYNC_FILE_RANGE_WAIT_BEFORE | + SYNC_FILE_RANGE_WRITE | + SYNC_FILE_RANGE_WAIT_AFTER); +#endif + +#ifdef fsync_no_flush + return fsync_no_flush(fd); +#endif + + errno = ENOSYS; + return -1; + + case FSYNC_HARDWARE_FLUSH: + /* + * On macOS, a special fcntl is required to really flush the + * caches within the storage controller. As of this writing, + * this is a very expensive operation on Apple SSDs. + */ +#ifdef __APPLE__ + return fcntl(fd, F_FULLFSYNC); +#else + return fsync_loop(fd); +#endif + default: + BUG("unexpected git_fsync(%d) call", action); + } +} + static int warn_if_unremovable(const char *op, const char *file, int rc) { int err; diff --git a/write-or-die.c b/write-or-die.c index a3d5784cec..c4fd91b5b4 100644 --- a/write-or-die.c +++ b/write-or-die.c @@ -56,16 +56,37 @@ void fprintf_or_die(FILE *f, const char *fmt, ...) } } -void fsync_or_die(int fd, const char *msg) +static int maybe_fsync(int fd) { if (use_fsync < 0) use_fsync = git_env_bool("GIT_TEST_FSYNC", 1); if (!use_fsync) - return; - while (fsync(fd) < 0) { - if (errno != EINTR) - die_errno("fsync error on '%s'", msg); - } + return 0; + + if (fsync_method == FSYNC_METHOD_WRITEOUT_ONLY && + git_fsync(fd, FSYNC_WRITEOUT_ONLY) >= 0) + return 0; + + return git_fsync(fd, FSYNC_HARDWARE_FLUSH); +} + +void fsync_or_die(int fd, const char *msg) +{ + if (maybe_fsync(fd) < 0) + die_errno("fsync error on '%s'", msg); +} + +int fsync_component(enum fsync_component component, int fd) +{ + if (fsync_components & component) + return maybe_fsync(fd); + return 0; +} + +void fsync_component_or_die(enum fsync_component component, int fd, const char *msg) +{ + if (fsync_components & component) + fsync_or_die(fd, msg); } void write_or_die(int fd, const void *buf, size_t count) |