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Merge branch 'np/maint-safer-pack' into maint
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* np/maint-safer-pack:
  fixup_pack_header_footer(): use nicely aligned buffer sizes
  index-pack: use fixup_pack_header_footer()'s validation mode
  pack-objects: use fixup_pack_header_footer()'s validation mode
  improve reliability of fixup_pack_header_footer()
  pack-objects: improve returned information from write_one()
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@gitster
gitster committed Sep 10, 2008
2 parents aaefbfa + d35825d commit 9f35e5f
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Showing 6 changed files with 112 additions and 55 deletions.
34 changes: 15 additions & 19 deletions builtin-pack-objects.c
View file
Expand Up @@ -410,35 +410,33 @@ static unsigned long write_object(struct sha1file *f,
return hdrlen + datalen;
}

static off_t write_one(struct sha1file *f,
static int write_one(struct sha1file *f,
struct object_entry *e,
off_t offset)
off_t *offset)
{
unsigned long size;

/* offset is non zero if object is written already. */
if (e->idx.offset || e->preferred_base)
return offset;
return 1;

/* if we are deltified, write out base object first. */
if (e->delta) {
offset = write_one(f, e->delta, offset);
if (!offset)
return 0;
}
if (e->delta && !write_one(f, e->delta, offset))
return 0;

e->idx.offset = offset;
size = write_object(f, e, offset);
e->idx.offset = *offset;
size = write_object(f, e, *offset);
if (!size) {
e->idx.offset = 0;
return 0;
}
written_list[nr_written++] = &e->idx;

/* make sure off_t is sufficiently large not to wrap */
if (offset > offset + size)
if (*offset > *offset + size)
die("pack too large for current definition of off_t");
return offset + size;
*offset += size;
return 1;
}

/* forward declaration for write_pack_file */
Expand All @@ -448,7 +446,7 @@ static void write_pack_file(void)
{
uint32_t i = 0, j;
struct sha1file *f;
off_t offset, offset_one, last_obj_offset = 0;
off_t offset;
struct pack_header hdr;
uint32_t nr_remaining = nr_result;
time_t last_mtime = 0;
Expand Down Expand Up @@ -480,11 +478,8 @@ static void write_pack_file(void)
offset = sizeof(hdr);
nr_written = 0;
for (; i < nr_objects; i++) {
last_obj_offset = offset;
offset_one = write_one(f, objects + i, offset);
if (!offset_one)
if (!write_one(f, objects + i, &offset))
break;
offset = offset_one;
display_progress(progress_state, written);
}

Expand All @@ -497,8 +492,9 @@ static void write_pack_file(void)
} else if (nr_written == nr_remaining) {
sha1close(f, sha1, CSUM_FSYNC);
} else {
int fd = sha1close(f, NULL, 0);
fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
int fd = sha1close(f, sha1, 0);
fixup_pack_header_footer(fd, sha1, pack_tmp_name,
nr_written, sha1, offset);
close(fd);
}

Expand Down
6 changes: 3 additions & 3 deletions csum-file.c
View file
Expand Up @@ -42,11 +42,11 @@ int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
sha1flush(f, offset);
f->offset = 0;
}
SHA1_Final(f->buffer, &f->ctx);
if (result)
hashcpy(result, f->buffer);
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);
Expand Down
3 changes: 2 additions & 1 deletion fast-import.c
View file
Expand Up @@ -951,7 +951,8 @@ static void end_packfile(void)

close_pack_windows(pack_data);
fixup_pack_header_footer(pack_data->pack_fd, pack_data->sha1,
pack_data->pack_name, object_count);
pack_data->pack_name, object_count,
NULL, 0);
close(pack_data->pack_fd);
idx_name = keep_pack(create_index());

Expand Down
44 changes: 26 additions & 18 deletions index-pack.c
View file
Expand Up @@ -654,7 +654,7 @@ static void parse_pack_objects(unsigned char *sha1)
}
}

static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
static int write_compressed(struct sha1file *f, void *in, unsigned int size)
{
z_stream stream;
unsigned long maxsize;
Expand All @@ -674,13 +674,12 @@ static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_c
deflateEnd(&stream);

size = stream.total_out;
write_or_die(fd, out, size);
*obj_crc = crc32(*obj_crc, out, size);
sha1write(f, out, size);
free(out);
return size;
}

static struct object_entry *append_obj_to_pack(
static struct object_entry *append_obj_to_pack(struct sha1file *f,
const unsigned char *sha1, void *buf,
unsigned long size, enum object_type type)
{
Expand All @@ -696,15 +695,15 @@ static struct object_entry *append_obj_to_pack(
s >>= 7;
}
header[n++] = c;
write_or_die(output_fd, header, n);
obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
crc32_begin(f);
sha1write(f, header, n);
obj[0].size = size;
obj[0].hdr_size = n;
obj[0].type = type;
obj[0].real_type = type;
obj[1].idx.offset = obj[0].idx.offset + n;
obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
obj[1].idx.offset += write_compressed(f, buf, size);
obj[0].idx.crc32 = crc32_end(f);
hashcpy(obj->idx.sha1, sha1);
return obj;
}
Expand All @@ -716,7 +715,7 @@ static int delta_pos_compare(const void *_a, const void *_b)
return a->obj_no - b->obj_no;
}

static void fix_unresolved_deltas(int nr_unresolved)
static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
{
struct delta_entry **sorted_by_pos;
int i, n = 0;
Expand Down Expand Up @@ -754,8 +753,8 @@ static void fix_unresolved_deltas(int nr_unresolved)
if (check_sha1_signature(d->base.sha1, base_obj.data,
base_obj.size, typename(type)))
die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
base_obj.obj = append_obj_to_pack(d->base.sha1, base_obj.data,
base_obj.size, type);
base_obj.obj = append_obj_to_pack(f, d->base.sha1,
base_obj.data, base_obj.size, type);
link_base_data(NULL, &base_obj);

find_delta_children(&d->base, &first, &last);
Expand Down Expand Up @@ -875,7 +874,7 @@ int main(int argc, char **argv)
const char *keep_name = NULL, *keep_msg = NULL;
char *index_name_buf = NULL, *keep_name_buf = NULL;
struct pack_idx_entry **idx_objects;
unsigned char sha1[20];
unsigned char pack_sha1[20];
int nongit = 0;

setup_git_directory_gently(&nongit);
Expand Down Expand Up @@ -962,13 +961,15 @@ int main(int argc, char **argv)
parse_pack_header();
objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
parse_pack_objects(sha1);
parse_pack_objects(pack_sha1);
if (nr_deltas == nr_resolved_deltas) {
stop_progress(&progress);
/* Flush remaining pack final 20-byte SHA1. */
flush();
} else {
if (fix_thin_pack) {
struct sha1file *f;
unsigned char read_sha1[20], tail_sha1[20];
char msg[48];
int nr_unresolved = nr_deltas - nr_resolved_deltas;
int nr_objects_initial = nr_objects;
Expand All @@ -977,12 +978,19 @@ int main(int argc, char **argv)
objects = xrealloc(objects,
(nr_objects + nr_unresolved + 1)
* sizeof(*objects));
fix_unresolved_deltas(nr_unresolved);
f = sha1fd(output_fd, curr_pack);
fix_unresolved_deltas(f, nr_unresolved);
sprintf(msg, "completed with %d local objects",
nr_objects - nr_objects_initial);
stop_progress_msg(&progress, msg);
fixup_pack_header_footer(output_fd, sha1,
curr_pack, nr_objects);
sha1close(f, tail_sha1, 0);
hashcpy(read_sha1, pack_sha1);
fixup_pack_header_footer(output_fd, pack_sha1,
curr_pack, nr_objects,
read_sha1, consumed_bytes-20);
if (hashcmp(read_sha1, tail_sha1) != 0)
die("Unexpected tail checksum for %s "
"(disk corruption?)", curr_pack);
}
if (nr_deltas != nr_resolved_deltas)
die("pack has %d unresolved deltas",
Expand All @@ -995,13 +1003,13 @@ int main(int argc, char **argv)
idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
for (i = 0; i < nr_objects; i++)
idx_objects[i] = &objects[i].idx;
curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
curr_index = write_idx_file(index_name, idx_objects, nr_objects, pack_sha1);
free(idx_objects);

final(pack_name, curr_pack,
index_name, curr_index,
keep_name, keep_msg,
sha1);
pack_sha1);
free(objects);
free(index_name_buf);
free(keep_name_buf);
Expand Down
78 changes: 65 additions & 13 deletions pack-write.c
View file
Expand Up @@ -144,41 +144,93 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects,
return index_name;
}

/*
* Update pack header with object_count and compute new SHA1 for pack data
* associated to pack_fd, and write that SHA1 at the end. That new SHA1
* is also returned in new_pack_sha1.
*
* If partial_pack_sha1 is non null, then the SHA1 of the existing pack
* (without the header update) is computed and validated against the
* one provided in partial_pack_sha1. The validation is performed at
* partial_pack_offset bytes in the pack file. The SHA1 of the remaining
* data (i.e. from partial_pack_offset to the end) is then computed and
* returned in partial_pack_sha1.
*
* Note that new_pack_sha1 is updated last, so both new_pack_sha1 and
* partial_pack_sha1 can refer to the same buffer if the caller is not
* interested in the resulting SHA1 of pack data above partial_pack_offset.
*/
void fixup_pack_header_footer(int pack_fd,
unsigned char *pack_file_sha1,
unsigned char *new_pack_sha1,
const char *pack_name,
uint32_t object_count)
uint32_t object_count,
unsigned char *partial_pack_sha1,
off_t partial_pack_offset)
{
static const int buf_sz = 128 * 1024;
SHA_CTX c;
int aligned_sz, buf_sz = 8 * 1024;
SHA_CTX old_sha1_ctx, new_sha1_ctx;
struct pack_header hdr;
char *buf;

SHA1_Init(&old_sha1_ctx);
SHA1_Init(&new_sha1_ctx);

if (lseek(pack_fd, 0, SEEK_SET) != 0)
die("Failed seeking to start: %s", strerror(errno));
die("Failed seeking to start of %s: %s", pack_name, strerror(errno));
if (read_in_full(pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
die("Unable to reread header of %s: %s", pack_name, strerror(errno));
if (lseek(pack_fd, 0, SEEK_SET) != 0)
die("Failed seeking to start: %s", strerror(errno));
die("Failed seeking to start of %s: %s", pack_name, strerror(errno));
SHA1_Update(&old_sha1_ctx, &hdr, sizeof(hdr));
hdr.hdr_entries = htonl(object_count);
SHA1_Update(&new_sha1_ctx, &hdr, sizeof(hdr));
write_or_die(pack_fd, &hdr, sizeof(hdr));

SHA1_Init(&c);
SHA1_Update(&c, &hdr, sizeof(hdr));
partial_pack_offset -= sizeof(hdr);

buf = xmalloc(buf_sz);
aligned_sz = buf_sz - sizeof(hdr);
for (;;) {
ssize_t n = xread(pack_fd, buf, buf_sz);
ssize_t m, n;
m = (partial_pack_sha1 && partial_pack_offset < aligned_sz) ?
partial_pack_offset : aligned_sz;
n = xread(pack_fd, buf, m);
if (!n)
break;
if (n < 0)
die("Failed to checksum %s: %s", pack_name, strerror(errno));
SHA1_Update(&c, buf, n);
SHA1_Update(&new_sha1_ctx, buf, n);

aligned_sz -= n;
if (!aligned_sz)
aligned_sz = buf_sz;

if (!partial_pack_sha1)
continue;

SHA1_Update(&old_sha1_ctx, buf, n);
partial_pack_offset -= n;
if (partial_pack_offset == 0) {
unsigned char sha1[20];
SHA1_Final(sha1, &old_sha1_ctx);
if (hashcmp(sha1, partial_pack_sha1) != 0)
die("Unexpected checksum for %s "
"(disk corruption?)", pack_name);
/*
* Now let's compute the SHA1 of the remainder of the
* pack, which also means making partial_pack_offset
* big enough not to matter anymore.
*/
SHA1_Init(&old_sha1_ctx);
partial_pack_offset = ~partial_pack_offset;
partial_pack_offset -= MSB(partial_pack_offset, 1);
}
}
free(buf);

SHA1_Final(pack_file_sha1, &c);
write_or_die(pack_fd, pack_file_sha1, 20);
if (partial_pack_sha1)
SHA1_Final(partial_pack_sha1, &old_sha1_ctx);
SHA1_Final(new_pack_sha1, &new_sha1_ctx);
write_or_die(pack_fd, new_pack_sha1, 20);
fsync_or_die(pack_fd, pack_name);
}

Expand Down
2 changes: 1 addition & 1 deletion pack.h
View file
Expand Up @@ -58,7 +58,7 @@ struct pack_idx_entry {
extern char *write_idx_file(char *index_name, struct pack_idx_entry **objects, int nr_objects, unsigned char *sha1);
extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
extern int verify_pack(struct packed_git *);
extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t);
extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
extern char *index_pack_lockfile(int fd);

#define PH_ERROR_EOF (-1)
Expand Down

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