Add config option to enable 'fsync()' of object files
As explained in the documentation[*] this is totally useless on filesystems that do ordered/journalled data writes, but it can be a useful safety feature on filesystems like HFS+ that only journal the metadata, not the actual file contents. It defaults to off, although we could presumably in theory some day auto-enable it on a per-filesystem basis. [*] Yes, I updated the docs for the thing. Hell really _has_ frozen over, and the four horsemen are probably just beyond the horizon. EVERYBODY PANIC! Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linus Torvalds committed
Jun 18, 2008 at 15:18 UTC
aafe9fbaf4f1d1f27a6f6e3eb3e246fff81240ef
5 files changed
+17
-1
Documentation/config.txt
+8
@@ -372,6 +372,14 @@ core.whitespace::
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does not trigger if the character before such a carriage-return
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is not a whitespace (not enabled by default).
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+core.fsyncobjectfiles::
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+ This boolean will enable 'fsync()' when writing object files.
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++
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+This is a total waste of time and effort on a filesystem that orders
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+data writes properly, but can be useful for filesystems that do not use
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+journalling (traditional UNIX filesystems) or that only journal metadata
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+and not file contents (OS X's HFS+, or Linux ext3 with "data=writeback").
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+
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alias.*::
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Command aliases for the linkgit:git[1] command wrapper - e.g.
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after defining "alias.last = cat-file commit HEAD", the invocation
cache.h
+1
@@ -435,6 +435,7 @@ extern size_t packed_git_window_size;
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extern size_t packed_git_limit;
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extern size_t delta_base_cache_limit;
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extern int auto_crlf;
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+extern int fsync_object_files;
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enum safe_crlf {
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SAFE_CRLF_FALSE = 0,
config.c
+5
@@ -460,6 +460,11 @@ static int git_default_core_config(const char *var, const char *value)
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return 0;
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}
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+ if (!strcmp(var, "core.fsyncobjectfiles")) {
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+ fsync_object_files = git_config_bool(var, value);
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+ return 0;
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+ }
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+
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/* Add other config variables here and to Documentation/config.txt. */
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return 0;
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}
environment.c
+1
@@ -29,6 +29,7 @@ const char *apply_default_whitespace;
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int zlib_compression_level = Z_BEST_SPEED;
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int core_compression_level;
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int core_compression_seen;
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+int fsync_object_files;
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size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
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size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
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size_t delta_base_cache_limit = 16 * 1024 * 1024;
sha1_file.c
+2
-1
@@ -2083,7 +2083,8 @@ int hash_sha1_file(const void *buf, unsigned long len, const char *type,
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/* Finalize a file on disk, and close it. */
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static void close_sha1_file(int fd)
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{
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- /* For safe-mode, we could fsync_or_die(fd, "sha1 file") here */
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+ if (fsync_object_files)
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+ fsync_or_die(fd, "sha1 file");
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fchmod(fd, 0444);
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if (close(fd) != 0)
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die("unable to write sha1 file");