[PATCH] git and symlinks as tracked content

Allow to store and track symlink in the repository. A symlink is stored
the same way as a regular file, only with the appropriate mode bits set.
The symlink target is therefore stored in a blob object.
This will hopefully make our udev repository fully functional. :)

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/cache.h b/cache.h
index 8dd8128..e6ce731 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -87,7 +87,14 @@ struct cache_entry {
 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 
 #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(S_IFLNK);
+       return htonl(mode);
+}
 
 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 
@@ -124,6 +131,7 @@ extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 #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);

diff --git a/check-files.c b/check-files.c
index 7d16691..bfd5590 100644 (file)
--- 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)

diff --git a/checkout-cache.c b/checkout-cache.c
index a1ef944..367b9c7 100644 (file)
--- a/checkout-cache.c
+++ b/checkout-cache.c
@@ -72,23 +72,41 @@ static int write_entry(struct cache_entry *ce, const char *path)
        unsigned long size;
        long wrote;
        char type[20];
+       char target[1024];
 
        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) {
+       switch (ntohl(ce->ce_mode) & S_IFMT) {
+       case S_IFREG:
+               fd = create_file(path, ntohl(ce->ce_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);
+               if (wrote != size)
+                       return error("checkout-cache: unable to write file %s", path);
+               break;
+       case S_IFLNK:
+               memcpy(target, new, size);
+               target[size] = '\0';
+               if (symlink(target, path)) {
+                       free(new);
+                       return error("checkout-cache: unable to create symlink %s (%s)",
+                               path, strerror(errno));
+               }
+               free(new);
+               break;
+       default:
                free(new);
-               return error("checkout-cache: unable to create %s (%s)",
-                       path, strerror(errno));
+               return error("checkout-cache: unknown file mode for %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 +119,7 @@ static int checkout_entry(struct cache_entry *ce, const char *base_dir)
        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;

diff --git a/diff-cache.c b/diff-cache.c
index 03dd69d..94c5f66 100644 (file)
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -24,7 +24,7 @@ static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned
                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) {

diff --git a/ls-files.c b/ls-files.c
index 8b53f2f..58b5aee 100644 (file)
--- 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);
                }

diff --git a/read-cache.c b/read-cache.c
index 53f1da8..5703f30 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -13,6 +13,16 @@ int cache_match_stat(struct cache_entry *ce, struct stat *st)
 {
        unsigned int changed = 0;
 
+       switch (ntohl(ce->ce_mode) & S_IFMT) {
+       case S_IFREG:
+               changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
+               break;
+       case S_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))

diff --git a/update-cache.c b/update-cache.c
index bb25fa1..05d584e 100644 (file)
--- a/update-cache.c
+++ b/update-cache.c
@@ -57,19 +57,16 @@ static int add_file_to_cache(char *path)
        struct cache_entry *ce;
        struct stat st;
        int fd;
+       unsigned int len;
+       char target[1024];
 
-       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);
@@ -78,10 +75,24 @@ static int add_file_to_cache(char *path)
        fill_stat_cache_info(ce, &st);
        ce->ce_mode = create_ce_mode(st.st_mode);
        ce->ce_flags = htons(namelen);
-
-       if (index_fd(ce->sha1, fd, &st) < 0)
+       switch (st.st_mode & S_IFMT) {
+       case S_IFREG:
+               fd = open(path, O_RDONLY);
+               if (fd < 0)
+                       return -1;
+               if (index_fd(ce->sha1, fd, &st) < 0)
+                       return -1;
+               break;
+       case 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;
+               break;
+       default:
                return -1;
-
+       }
        return add_cache_entry(ce, allow_add);
 }
 
@@ -137,7 +148,7 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
        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 +156,10 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
                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))