Make sure objects/pack exists before creating a new pack

In a repository created with git older than f49fb35 (git-init-db: create
"pack" subdirectory under objects, 2005-06-27), objects/pack/ directory is
not created upon initialization.  It was Ok because subdirectories are
created as needed inside directories init-db creates, and back then,
packfiles were recent invention.

After the said commit, new codepaths started relying on the presense of
objects/pack/ directory in the repository.  This was exacerbated with
8b4eb6b (Do not perform cross-directory renames when creating packs,
2008-09-22) that moved the location temporary pack files are created from
objects/ directory to objects/pack/ directory, because moving temporary to
the final location was done carefully with lazy leading directory creation.

Many packfile related operations in such an old repository can fail
mysteriously because of this.

This commit introduces two helper functions to make things work better.

 - odb_mkstemp() is a specialized version of mkstemp() to refactor the
   code and teach it to create leading directories as needed;

 - odb_pack_keep() refactors the code to create a ".keep" file while
   create leading directories as needed.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index fb5e14d56e5b9fec0a054eb9708be41a59ac0f13..7518d536c3d7d827322d335ad87fe26f5853c550 100644 (file)
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -473,9 +473,8 @@ static void write_pack_file(void)
                } else {
                        char tmpname[PATH_MAX];
                        int fd;
-                       snprintf(tmpname, sizeof(tmpname),
-                                "%s/pack/tmp_pack_XXXXXX", get_object_directory());
-                       fd = xmkstemp(tmpname);
+                       fd = odb_mkstemp(tmpname, sizeof(tmpname),
+                                        "pack/tmp_pack_XXXXXX");
                        pack_tmp_name = xstrdup(tmpname);
                        f = sha1fd(fd, pack_tmp_name);
                }

diff --git a/fast-import.c b/fast-import.c
index d58cca58e5fdbe0838e3622148d7b502affeaebf..f0114948ec1a48b5fa8fa848c231e0c37c2e7426 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -815,9 +815,8 @@ static void start_packfile(void)
        struct pack_header hdr;
        int pack_fd;
 
-       snprintf(tmpfile, sizeof(tmpfile),
-               "%s/pack/tmp_pack_XXXXXX", get_object_directory());
-       pack_fd = xmkstemp(tmpfile);
+       pack_fd = odb_mkstemp(tmpfile, sizeof(tmpfile),
+                             "pack/tmp_pack_XXXXXX");
        p = xcalloc(1, sizeof(*p) + strlen(tmpfile) + 2);
        strcpy(p->pack_name, tmpfile);
        p->pack_fd = pack_fd;
@@ -877,9 +876,8 @@ static char *create_index(void)
                c = next;
        }
 
-       snprintf(tmpfile, sizeof(tmpfile),
-               "%s/pack/tmp_idx_XXXXXX", get_object_directory());
-       idx_fd = xmkstemp(tmpfile);
+       idx_fd = odb_mkstemp(tmpfile, sizeof(tmpfile),
+                            "pack/tmp_idx_XXXXXX");
        f = sha1fd(idx_fd, tmpfile);
        sha1write(f, array, 256 * sizeof(int));
        SHA1_Init(&ctx);
@@ -905,9 +903,7 @@ static char *keep_pack(char *curr_index_name)
        chmod(pack_data->pack_name, 0444);
        chmod(curr_index_name, 0444);
 
-       snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
-                get_object_directory(), sha1_to_hex(pack_data->sha1));
-       keep_fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
+       keep_fd = odb_pack_keep(name, sizeof(name), pack_data->sha1);
        if (keep_fd < 0)
                die("cannot create keep file");
        write_or_die(keep_fd, keep_msg, strlen(keep_msg));

diff --git a/git-compat-util.h b/git-compat-util.h
index cf89cdf4598b3796724a85aa707f740245155cdc..758a8808628e1dfb8240ee2fb3f8e4e359cf07f0 100644 (file)
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -294,6 +294,8 @@ extern ssize_t xwrite(int fd, const void *buf, size_t len);
 extern int xdup(int fd);
 extern FILE *xfdopen(int fd, const char *mode);
 extern int xmkstemp(char *template);
+extern int odb_mkstemp(char *template, size_t limit, const char *pattern);
+extern int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1);
 
 static inline size_t xsize_t(off_t len)
 {

diff --git a/index-pack.c b/index-pack.c
index c99a1a152c7ddbb63073461b86179f2be5bf9640..745ac0bfa02aafc00b3379011259a6bfc5a47f7b 100644 (file)
--- a/index-pack.c
+++ b/index-pack.c
@@ -171,9 +171,8 @@ static char *open_pack_file(char *pack_name)
                input_fd = 0;
                if (!pack_name) {
                        static char tmpfile[PATH_MAX];
-                       snprintf(tmpfile, sizeof(tmpfile),
-                                "%s/pack/tmp_pack_XXXXXX", get_object_directory());
-                       output_fd = xmkstemp(tmpfile);
+                       output_fd = odb_mkstemp(tmpfile, sizeof(tmpfile),
+                                               "pack/tmp_pack_XXXXXX");
                        pack_name = xstrdup(tmpfile);
                } else
                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
@@ -795,22 +794,24 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 
        if (keep_msg) {
                int keep_fd, keep_msg_len = strlen(keep_msg);
-               if (!keep_name) {
-                       snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
-                                get_object_directory(), sha1_to_hex(sha1));
-                       keep_name = name;
-               }
-               keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
+
+               if (!keep_name)
+                       keep_fd = odb_pack_keep(name, sizeof(name), sha1);
+               else
+                       keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
+
                if (keep_fd < 0) {
                        if (errno != EEXIST)
-                               die("cannot write keep file");
+                               die("cannot write keep file '%s' (%s)",
+                                   keep_name, strerror(errno));
                } else {
                        if (keep_msg_len > 0) {
                                write_or_die(keep_fd, keep_msg, keep_msg_len);
                                write_or_die(keep_fd, "\n", 1);
                        }
                        if (close(keep_fd) != 0)
-                               die("cannot write keep file");
+                               die("cannot close written keep file '%s' (%s)",
+                                   keep_name, strerror(errno));
                        report = "keep";
                }
        }

diff --git a/pack-write.c b/pack-write.c
index 3621f1dd3258d9dcd63bf5a6738e5d54940ffbbb..e82c02545794fd10d2a81863676005e14069ce21 100644 (file)
--- a/pack-write.c
+++ b/pack-write.c
@@ -44,9 +44,7 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects,
 
        if (!index_name) {
                static char tmpfile[PATH_MAX];
-               snprintf(tmpfile, sizeof(tmpfile),
-                        "%s/pack/tmp_idx_XXXXXX", get_object_directory());
-               fd = xmkstemp(tmpfile);
+               fd = odb_mkstemp(tmpfile, sizeof(tmpfile), "pack/tmp_idx_XXXXXX");
                index_name = xstrdup(tmpfile);
        } else {
                unlink(index_name);
@@ -239,7 +237,7 @@ char *index_pack_lockfile(int ip_out)
        char packname[46];
 
        /*
-        * The first thing we expects from index-pack's output
+        * The first thing we expect from index-pack's output
         * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
         * %40s is the newly created pack SHA1 name.  In the "keep"
         * case, we need it to remove the corresponding .keep file

diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh
index 2852a0326546f50f0cbefb4d5621c889b52f33c9..73d871c7133d8cc392bc4ccea93fed4f750b2edf 100755 (executable)
--- a/t/t5300-pack-object.sh
+++ b/t/t5300-pack-object.sh
@@ -180,6 +180,23 @@ test_expect_success \
 
 unset GIT_OBJECT_DIRECTORY
 
+test_expect_success 'survive missing objects/pack directory' '
+       (
+               rm -fr missing-pack &&
+               mkdir missing-pack &&
+               cd missing-pack &&
+               git init &&
+               GOP=.git/objects/pack
+               rm -fr $GOP &&
+               git index-pack --stdin --keep=test <../test-3-${packname_3}.pack &&
+               test -f $GOP/pack-${packname_3}.pack &&
+               test_cmp $GOP/pack-${packname_3}.pack ../test-3-${packname_3}.pack &&
+               test -f $GOP/pack-${packname_3}.idx &&
+               test_cmp $GOP/pack-${packname_3}.idx ../test-3-${packname_3}.idx &&
+               test -f $GOP/pack-${packname_3}.keep
+       )
+'
+
 test_expect_success \
     'verify pack' \
     'git verify-pack   test-1-${packname_1}.idx \

diff --git a/wrapper.c b/wrapper.c
index 93562f03eef21b26945d2d9bbdc96818f4de6567..231a58f1a9581b2f7e150ffe4e2f908dca3e3e61 100644 (file)
--- a/wrapper.c
+++ b/wrapper.c
@@ -196,3 +196,35 @@ int xmkstemp(char *template)
                die("Unable to create temporary file: %s", strerror(errno));
        return fd;
 }
+
+int odb_mkstemp(char *template, size_t limit, const char *pattern)
+{
+       int fd;
+
+       snprintf(template, limit, "%s/%s",
+                get_object_directory(), pattern);
+       fd = mkstemp(template);
+       if (0 <= fd)
+               return fd;
+
+       /* slow path */
+       safe_create_leading_directories(template);
+       snprintf(template, limit, "%s/%s",
+                get_object_directory(), pattern);
+       return xmkstemp(template);
+}
+
+int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
+{
+       int fd;
+
+       snprintf(name, namesz, "%s/pack/pack-%s.keep",
+                get_object_directory(), sha1_to_hex(sha1));
+       fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
+       if (0 <= fd)
+               return fd;
+
+       /* slow path */
+       safe_create_leading_directories(name);
+       return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
+}