Permalink
Browse files

Make pack creation always fsync() the result

This means that we can depend on packs always being stable on disk,
simplifying a lot of the object serialization worries.  And unlike loose
objects, serializing pack creation IO isn't going to be a performance
killer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
  • Loading branch information...
1 parent d2b3691 commit 4c81b03e30d13dbc93ea7071438ef2da0acd4189 @torvalds torvalds committed with gitster May 30, 2008
Showing with 24 additions and 6 deletions.
  1. +3 −1 builtin-pack-objects.c
  2. +1 −0 cache.h
  3. +5 −2 csum-file.c
  4. +5 −1 csum-file.h
  5. +1 −1 fast-import.c
  6. +1 −0 index-pack.c
  7. +1 −1 pack-write.c
  8. +7 −0 write_or_die.c
@@ -515,10 +515,12 @@ static void write_pack_file(void)
* If so, rewrite it like in fast-import
*/
if (pack_to_stdout || nr_written == nr_remaining) {
- sha1close(f, sha1, 1);
+ unsigned flags = pack_to_stdout ? CSUM_CLOSE : CSUM_FSYNC;
+ sha1close(f, sha1, flags);
} else {
int fd = sha1close(f, NULL, 0);
fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
+ fsync_or_die(fd, pack_tmp_name);
close(fd);
}
View
@@ -761,6 +761,7 @@ extern ssize_t write_in_full(int fd, const void *buf, size_t count);
extern void write_or_die(int fd, const void *buf, size_t count);
extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
extern int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg);
+extern void fsync_or_die(int fd, const char *);
/* pager.c */
extern void setup_pager(void);
View
@@ -32,21 +32,24 @@ static void sha1flush(struct sha1file *f, unsigned int count)
}
}
-int sha1close(struct sha1file *f, unsigned char *result, int final)
+int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
{
int fd;
unsigned offset = f->offset;
+
if (offset) {
SHA1_Update(&f->ctx, f->buffer, offset);
sha1flush(f, offset);
f->offset = 0;
}
- if (final) {
+ if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
/* write checksum and close fd */
SHA1_Final(f->buffer, &f->ctx);
if (result)
hashcpy(result, f->buffer);
sha1flush(f, 20);
+ if (flags & CSUM_FSYNC)
+ fsync_or_die(f->fd, f->name);
if (close(f->fd))
die("%s: sha1 file error on close (%s)",
f->name, strerror(errno));
View
@@ -16,9 +16,13 @@ struct sha1file {
unsigned char buffer[8192];
};
+/* sha1close flags */
+#define CSUM_CLOSE 1
+#define CSUM_FSYNC 2
+
extern struct sha1file *sha1fd(int fd, const char *name);
extern struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp);
-extern int sha1close(struct sha1file *, unsigned char *, int);
+extern int sha1close(struct sha1file *, unsigned char *, unsigned int);
extern int sha1write(struct sha1file *, void *, unsigned int);
extern void crc32_begin(struct sha1file *);
extern uint32_t crc32_end(struct sha1file *);
View
@@ -890,7 +890,7 @@ static char *create_index(void)
SHA1_Update(&ctx, (*c)->sha1, 20);
}
sha1write(f, pack_data->sha1, sizeof(pack_data->sha1));
- sha1close(f, NULL, 1);
+ sha1close(f, NULL, CSUM_FSYNC);
free(idx);
SHA1_Final(pack_data->sha1, &ctx);
return tmpfile;
View
@@ -694,6 +694,7 @@ 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);
err = close(output_fd);
if (err)
die("error while closing pack file: %s", strerror(errno));
View
@@ -139,7 +139,7 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects,
}
sha1write(f, sha1, 20);
- sha1close(f, NULL, 1);
+ sha1close(f, NULL, CSUM_FSYNC);
SHA1_Final(sha1, &ctx);
return index_name;
}
View
@@ -78,6 +78,13 @@ ssize_t write_in_full(int fd, const void *buf, size_t count)
return total;
}
+void fsync_or_die(int fd, const char *msg)
+{
+ if (fsync(fd) < 0) {
+ die("%s: fsync error (%s)", msg, strerror(errno));
+ }
+}
+
void write_or_die(int fd, const void *buf, size_t count)
{
if (write_in_full(fd, buf, count) < 0) {

0 comments on commit 4c81b03

Please sign in to comment.