]> rtime.felk.cvut.cz Git - git.git/commitdiff
Merge branch 'np/maint-safer-pack' into np/pack
authorJunio C Hamano <gitster@pobox.com>
Wed, 3 Sep 2008 00:05:44 +0000 (17:05 -0700)
committerJunio C Hamano <gitster@pobox.com>
Wed, 3 Sep 2008 00:05:44 +0000 (17:05 -0700)
* 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()

builtin-pack-objects.c
csum-file.c
fast-import.c
index-pack.c
pack-write.c
pack.h

index ef3befe57b3b8298798e51627f076e2a40319cb1..ba2cf00f5ec60bcfcefe120746422f086559a1ae 100644 (file)
@@ -410,25 +410,22 @@ 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;
@@ -436,9 +433,10 @@ static off_t write_one(struct sha1file *f,
        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 */
@@ -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;
@@ -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);
                }
 
@@ -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);
                }
 
index ace64f165e4a01fb99892e9b89e7df791a7f4ca1..28389541a32454f2d988bb02e4268ffe12755bbc 100644 (file)
@@ -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);
index 7089e6f9e6c5fa9142f468e54afe7d33a6d2eec7..d85b3a561f511bfa7db0232c43a8088c0df8ae27 100644 (file)
@@ -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());
 
index 728af7da9c87646a869af5da5444943c0c66f89e..a6e91fe3ba47e3b0837648180bb7d47acd3e7dc7 100644 (file)
@@ -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;
@@ -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)
 {
@@ -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;
 }
@@ -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;
@@ -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);
@@ -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);
@@ -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;
@@ -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",
@@ -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);
index ddcfd37af263a5fe1009473cba879b00f4b6692d..939ed56362d3c29bfc64e8cca91032df9a57961e 100644 (file)
@@ -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);
 }
 
diff --git a/pack.h b/pack.h
index 76e6aa2aad06545e7c44fc2c1e117ea668356ccf..a883334b269c76d8de1395adf2b8f3d0d7e8564f 100644 (file)
--- a/pack.h
+++ b/pack.h
@@ -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)