From: Kay Sievers <kay.sievers@vrfy.org>
To: Junio C Hamano <junkio@cox.net>
Cc: Linus Torvalds <torvalds@osdl.org>, git@vger.kernel.org
Subject: Re: git and symlinks as tracked content
Date: Thu, 5 May 2005 03:20:51 +0200 [thread overview]
Message-ID: <20050505012051.GA26201@vrfy.org> (raw)
In-Reply-To: <7vwtqemvjt.fsf@assigned-by-dhcp.cox.net>
Allow to store and track symlink in the repository. A symlink is stored
the same way as a regular file, but with the appropriate mode bits set.
The symlink target is stored in its own blob object. This will hopefully
make our udev repository fully functional. :)
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
---
On Wed, May 04, 2005 at 04:16:22PM -0700, Junio C Hamano wrote:
> It seems to follow the original suggestion by Linus and looks
> good. Some comments:
>
> * It continues to assume that S_IFREG, S_IFDIR and S_IFLNK have
> the same bit pattern everywhere. In the same spirit as we
> store mode bits in network byte order, it may be a good time
> to introduce something like this:
...
> * read-cache.c:cache_match_stat() needs to know about the
> object type. It was allowed to assume that anything thrown
> at it was a file, but not anymore. How about something like
> this:
Both included and updated.
> * (this is just a minor nit). Since you have st here,
> st.st_size can be used to see how big a buffer you need to
> prepare for readlink() here:
Sounds nice, but is this reliable? I just remember some exotic filesystems
to reported bogus values here.
> * Probably diff.c needs to be made aware of this change.
You already did this. :) Very nice.
Thanks,
Kay
--- a/cache.h
+++ b/cache.h
@@ -86,8 +86,19 @@ struct cache_entry {
#define ce_size(ce) cache_entry_size(ce_namelen(ce))
#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
+#define CE_IFREG 0100000
+#define CE_IFDIR 0040000
+#define CE_IFLNK 0120000
+#define CE_IFMASK 0770000
#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
-#define create_ce_mode(mode) htonl(S_IFREG | ce_permissions(mode))
+static inline unsigned int create_ce_mode(unsigned int mode)
+{
+ if (S_ISREG(mode))
+ return htonl(S_IFREG | ce_permissions(mode));
+ if (S_ISLNK(mode))
+ return htonl(CE_IFLNK);
+ return 0;
+}
#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
@@ -124,6 +135,7 @@ extern int index_fd(unsigned char *sha1,
#define MODE_CHANGED 0x0008
#define INODE_CHANGED 0x0010
#define DATA_CHANGED 0x0020
+#define TYPE_CHANGED 0x0040
/* Return a statically allocated filename matching the sha1 signature */
extern char *sha1_file_name(const unsigned char *sha1);
--- a/check-files.c
+++ b/check-files.c
@@ -28,8 +28,8 @@ static void check_file(const char *path)
die("preparing to update existing file '%s' not in cache", path);
ce = active_cache[pos];
- if (fstat(fd, &st) < 0)
- die("fstat(%s): %s", path, strerror(errno));
+ if (lstat(path, &st) < 0)
+ die("lstat(%s): %s", path, strerror(errno));
changed = cache_match_stat(ce, &st);
if (changed)
--- a/checkout-cache.c
+++ b/checkout-cache.c
@@ -72,23 +72,37 @@ static int write_entry(struct cache_entr
unsigned long size;
long wrote;
char type[20];
+ unsigned int mode;
new = read_sha1_file(ce->sha1, type, &size);
if (!new || strcmp(type, "blob")) {
return error("checkout-cache: unable to read sha1 file of %s (%s)",
path, sha1_to_hex(ce->sha1));
}
- fd = create_file(path, ntohl(ce->ce_mode));
- if (fd < 0) {
+ mode = ntohl(ce->ce_mode);
+ if (S_ISLNK(mode)) {
+ char target[1024];
+ memcpy(target, new, size);
+ target[size] = '\0';
+ if (symlink(target, path)) {
+ free(new);
+ return error("checkout-cache: unable to create link %s (%s)",
+ path, strerror(errno));
+ }
+ free(new);
+ } else {
+ fd = create_file(path, mode);
+ if (fd < 0) {
+ free(new);
+ return error("checkout-cache: unable to create file %s (%s)",
+ path, strerror(errno));
+ }
+ wrote = write(fd, new, size);
+ close(fd);
free(new);
- return error("checkout-cache: unable to create %s (%s)",
- path, strerror(errno));
+ if (wrote != size)
+ return error("checkout-cache: unable to write %s", path);
}
- wrote = write(fd, new, size);
- close(fd);
- free(new);
- if (wrote != size)
- return error("checkout-cache: unable to write %s", path);
return 0;
}
@@ -101,7 +115,7 @@ static int checkout_entry(struct cache_e
memcpy(path, base_dir, len);
strcpy(path + len, ce->name);
- if (!stat(path, &st)) {
+ if (!lstat(path, &st)) {
unsigned changed = cache_match_stat(ce, &st);
if (!changed)
return 0;
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -24,7 +24,7 @@ static int get_stat_data(struct cache_en
static unsigned char no_sha1[20];
int changed;
struct stat st;
- if (stat(ce->name, &st) < 0)
+ if (lstat(ce->name, &st) < 0)
return -1;
changed = cache_match_stat(ce, &st);
if (changed) {
--- a/diff.c
+++ b/diff.c
@@ -165,7 +165,7 @@ static void prepare_temp_file(const char
}
strcpy(temp->hex, sha1_to_hex(null_sha1));
sprintf(temp->mode, "%06o",
- S_IFREG |ce_permissions(st.st_mode));
+ S_IFREG | ce_permissions(st.st_mode));
}
else {
int fd;
--- a/ls-files.c
+++ b/ls-files.c
@@ -199,7 +199,7 @@ static void show_files(void)
struct stat st;
if (excluded(ce->name) != show_ignored)
continue;
- if (!stat(ce->name, &st))
+ if (!lstat(ce->name, &st))
continue;
printf("%s%c", ce->name, line_terminator);
}
--- a/read-cache.c
+++ b/read-cache.c
@@ -13,6 +13,16 @@ int cache_match_stat(struct cache_entry
{
unsigned int changed = 0;
+ switch (ntohl(ce->ce_mode) & CE_IFMASK) {
+ case CE_IFREG:
+ changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
+ break;
+ case CE_IFLNK:
+ changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0;
+ break;
+ default:
+ die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
+ }
if (ce->ce_mtime.sec != htonl(st->st_mtime))
changed |= MTIME_CHANGED;
if (ce->ce_ctime.sec != htonl(st->st_ctime))
--- a/tree.c
+++ b/tree.c
@@ -13,7 +13,10 @@ static int read_one_entry(unsigned char
memset(ce, 0, size);
- ce->ce_mode = create_ce_mode(mode);
+ if (mode & S_IFMT)
+ ce->ce_mode = htonl(mode);
+ else
+ ce->ce_mode = create_ce_mode(mode);
ce->ce_flags = create_ce_flags(baselen + len, stage);
memcpy(ce->name, base, baselen);
memcpy(ce->name + baselen, pathname, len+1);
--- a/update-cache.c
+++ b/update-cache.c
@@ -58,30 +58,37 @@ static int add_file_to_cache(char *path)
struct stat st;
int fd;
- fd = open(path, O_RDONLY);
- if (fd < 0) {
+ if (lstat(path, &st) < 0) {
if (errno == ENOENT || errno == ENOTDIR) {
if (allow_remove)
return remove_file_from_cache(path);
}
return -1;
}
- if (fstat(fd, &st) < 0) {
- close(fd);
- return -1;
- }
namelen = strlen(path);
size = cache_entry_size(namelen);
ce = xmalloc(size);
memset(ce, 0, size);
memcpy(ce->name, path, namelen);
fill_stat_cache_info(ce, &st);
- ce->ce_mode = create_ce_mode(st.st_mode);
+ if (S_ISREG(st.st_mode)) {
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -1;
+ ce->ce_mode = create_ce_mode(st.st_mode);
+ if (index_fd(ce->sha1, fd, &st) < 0)
+ return -1;
+ } else if (S_ISLNK(st.st_mode)) {
+ unsigned int len;
+ char target[1024];
+ ce->ce_mode = htonl(S_IFLNK);
+ len = readlink(path, target, sizeof(target));
+ if (len == -1 || len+1 > sizeof(target))
+ return -1;
+ if (write_sha1_file(target, len, "blob", ce->sha1))
+ return -1;
+ }
ce->ce_flags = htons(namelen);
-
- if (index_fd(ce->sha1, fd, &st) < 0)
- return -1;
-
return add_cache_entry(ce, allow_add);
}
@@ -137,7 +144,7 @@ static struct cache_entry *refresh_entry
struct cache_entry *updated;
int changed, size;
- if (stat(ce->name, &st) < 0)
+ if (lstat(ce->name, &st) < 0)
return ERR_PTR(-errno);
changed = cache_match_stat(ce, &st);
@@ -145,10 +152,10 @@ static struct cache_entry *refresh_entry
return ce;
/*
- * If the mode has changed, there's no point in trying
+ * If the mode or type has changed, there's no point in trying
* to refresh the entry - it's not going to match
*/
- if (changed & MODE_CHANGED)
+ if (changed & (MODE_CHANGED | TYPE_CHANGED))
return ERR_PTR(-EINVAL);
if (compare_data(ce, st.st_size))
next prev parent reply other threads:[~2005-05-05 1:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-03 18:33 git and symlinks as tracked content Kay Sievers
2005-05-03 19:02 ` Linus Torvalds
2005-05-03 19:10 ` Morten Welinder
2005-05-03 19:50 ` H. Peter Anvin
2005-05-03 19:57 ` Andreas Gal
2005-05-03 20:05 ` Linus Torvalds
2005-05-03 20:09 ` Kay Sievers
2005-05-03 21:30 ` Junio C Hamano
2005-05-03 21:51 ` Andreas Gal
2005-05-03 22:44 ` Junio C Hamano
2005-05-04 0:39 ` Sym-links, b/c-special files, pipes, ... Scope Creep Brian O'Mahoney
2005-05-03 22:56 ` git and symlinks as tracked content H. Peter Anvin
2005-05-03 23:16 ` Junio C Hamano
2005-05-03 23:18 ` H. Peter Anvin
2005-05-03 23:42 ` Linus Torvalds
2005-05-03 23:42 ` Junio C Hamano
2005-05-04 15:48 ` David A. Wheeler
2005-05-04 23:03 ` Daniel Barkalow
2005-05-05 6:09 ` Alan Chandler
2005-05-05 9:51 ` read-only git repositories David Lang
2005-05-05 12:39 ` Sean
2005-05-06 3:01 ` read-only git repositories (ancient history) David A. Wheeler
2005-05-05 21:23 ` git and symlinks as tracked content Daniel Barkalow
2005-05-03 20:23 ` Junio C Hamano
2005-05-04 22:35 ` Kay Sievers
2005-05-04 23:16 ` Junio C Hamano
2005-05-05 1:20 ` Kay Sievers [this message]
2005-05-05 2:13 ` Junio C Hamano
2005-05-05 12:38 ` Kay Sievers
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