[PATCH] Careful object pulling
This splits out the careful methods for writing a file and placing it in the correct location from the function to write a buffer to the file and makes the various functions used by git-*-pull programs use those functions to write their files.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Index: cache.h
===================================================================
--- 51a882a2dc62e0d3cdc79e0badc61559fb723481/cache.h (mode:100644 sha1:8dd812827604d510038f5d93e3718c43f9d12c30)
+++ 4e31436bacfff09ce673665a1061b41e37ffd661/cache.h (mode:100644 sha1:0d7411c3b86a899cee45627997f4bb7ba0df2ea7)
@@ -134,6 +134,12 @@
extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
extern int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *return_sha1);
+/* Open a file for writing a sha1 file. */
+extern int open_sha1_tmpfile(char tmpfile[PATH_MAX]);
+
+/* Put a sha1 file in the correct place. */
+extern int place_sha1_file(char tmpfile[PATH_MAX], const unsigned char *sha1);
+
extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
/* Read a tree into the cache */
Index: http-pull.c
===================================================================
--- 51a882a2dc62e0d3cdc79e0badc61559fb723481/http-pull.c (mode:100644 sha1:f693aba61b4dcb4b738faf1335ec74aa1545e45d)
+++ 4e31436bacfff09ce673665a1061b41e37ffd661/http-pull.c (mode:100644 sha1:793d8b9e125c1f164f774e2888d26beaa75e1df0)
@@ -52,8 +52,9 @@
char real_sha1[20];
char *url;
char *posn;
+ char tmpname[PATH_MAX];
- local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+ local = open_sha1_tmpfile(tmpname);
if (local < 0)
return error("Couldn't open %s\n", filename);
@@ -88,15 +89,14 @@
inflateEnd(&stream);
SHA1_Final(real_sha1, &c);
if (zret != Z_STREAM_END) {
- unlink(filename);
+ unlink(tmpname);
return error("File %s (%s) corrupt\n", hex, url);
}
if (memcmp(sha1, real_sha1, 20)) {
- unlink(filename);
+ unlink(tmpname);
return error("File %s has bad hash\n", hex);
}
-
- return 0;
+ return place_sha1_file(tmpname, sha1);
}
int main(int argc, char **argv)
Index: sha1_file.c
===================================================================
--- 51a882a2dc62e0d3cdc79e0badc61559fb723481/sha1_file.c (mode:100644 sha1:e6ce455ae90bd430f2128f454bdb6e0575412486)
+++ 4e31436bacfff09ce673665a1061b41e37ffd661/sha1_file.c (mode:100644 sha1:85daa0b0045c3f19e697d1a7aa8ab15ff54eab99)
@@ -276,6 +276,55 @@
}
}
+int open_sha1_tmpfile(char tmpfile[PATH_MAX])
+{
+ int fd;
+
+ snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
+ fd = mkstemp(tmpfile);
+ if (fd < 0) {
+ fprintf(stderr,
+ "unable to create temporary sha1 filename %s: %s",
+ tmpfile, strerror(errno));
+ return -1;
+ }
+ return fd;
+}
+
+int place_sha1_file(char tmpfile[PATH_MAX], const unsigned char *sha1)
+{
+ char *filename = sha1_file_name(sha1);
+ int ret;
+
+ ret = link(tmpfile, filename);
+ if (ret < 0) {
+ ret = errno;
+
+ /*
+ * Coda hack - coda doesn't like cross-directory links,
+ * so we fall back to a rename, which will mean that it
+ * won't be able to check collisions, but that's not a
+ * big deal.
+ *
+ * When this succeeds, we just return 0. We have nothing
+ * left to unlink.
+ */
+ if (ret == EXDEV && !rename(tmpfile, filename))
+ return 0;
+ }
+ unlink(tmpfile);
+ if (ret) {
+ if (ret != EEXIST) {
+ fprintf(stderr,
+ "unable to write sha1 filename %s: %s",
+ filename, strerror(ret));
+ return -1;
+ }
+ /* FIXME!!! Collision check here ? */
+ }
+ return 0;
+}
+
int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)
{
int size;
@@ -286,7 +335,7 @@
char *filename;
static char tmpfile[PATH_MAX];
char hdr[50];
- int fd, hdrlen, ret;
+ int fd, hdrlen;
/* Generate the header */
hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
@@ -316,12 +365,9 @@
return -1;
}
- snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
- fd = mkstemp(tmpfile);
- if (fd < 0) {
- fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
- return -1;
- }
+ fd = open_sha1_tmpfile(tmpfile);
+ if (fd < 0)
+ return fd;
/* Set it up */
memset(&stream, 0, sizeof(stream));
@@ -349,53 +395,28 @@
if (write(fd, compressed, size) != size)
die("unable to write file");
+
fchmod(fd, 0444);
close(fd);
- ret = link(tmpfile, filename);
- if (ret < 0) {
- ret = errno;
-
- /*
- * Coda hack - coda doesn't like cross-directory links,
- * so we fall back to a rename, which will mean that it
- * won't be able to check collisions, but that's not a
- * big deal.
- *
- * When this succeeds, we just return 0. We have nothing
- * left to unlink.
- */
- if (ret == EXDEV && !rename(tmpfile, filename))
- return 0;
- }
- unlink(tmpfile);
- if (ret) {
- if (ret != EEXIST) {
- fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
- return -1;
- }
- /* FIXME!!! Collision check here ? */
- }
-
- return 0;
+ return place_sha1_file(tmpfile, sha1);
}
int write_sha1_from_fd(const unsigned char *sha1, int fd)
{
- char *filename = sha1_file_name(sha1);
-
int local;
z_stream stream;
unsigned char real_sha1[20];
char buf[4096];
char discard[4096];
+ char tmpname[PATH_MAX];
int ret;
SHA_CTX c;
- local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+ local = open_sha1_tmpfile(tmpname);
if (local < 0)
- return error("Couldn't open %s\n", filename);
+ return -1;
memset(&stream, 0, sizeof(stream));
@@ -408,7 +429,7 @@
size = read(fd, buf, 4096);
if (size <= 0) {
close(local);
- unlink(filename);
+ unlink(tmpname);
if (!size)
return error("Connection closed?");
perror("Reading from connection");
@@ -431,15 +452,15 @@
close(local);
SHA1_Final(real_sha1, &c);
if (ret != Z_STREAM_END) {
- unlink(filename);
+ unlink(tmpname);
return error("File %s corrupted", sha1_to_hex(sha1));
}
if (memcmp(sha1, real_sha1, 20)) {
- unlink(filename);
+ unlink(tmpname);
return error("File %s has bad hash\n", sha1_to_hex(sha1));
}
-
- return 0;
+
+ return place_sha1_file(tmpname, sha1);
}
int has_sha1_file(const unsigned char *sha1)
Linus Torvalds
