[PATCH] usr/gen_init_cpio.c: support for hard links

Extend usr/gen_init_cpio.c "file" entry, adding support for hard links. Previous format: file <name> <location> <mode> <uid> <gid> New format: file <name> <location> <mode> <uid> <gid> [<hard links>] The hard links specification is optional, keeping the previous behaviour. All hard links are defined sequentially in the resulting cpio and the file data is present only in the last link. This is the behaviour of GNU's cpio and is supported by the kernel initramfs extractor. Signed-off-by: Luciano Rocha <strange@nsk.no-ip.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] usr/gen_init_cpio.c: support for hard links
Extend usr/gen_init_cpio.c "file" entry, adding support for hard links. Previous format: file <name> <location> <mode> <uid> <gid> New format: file <name> <location> <mode> <uid> <gid> [<hard links>] The hard links specification is optional, keeping the previous behaviour. All hard links are defined sequentially in the resulting cpio and the file data is present only in the last link. This is the behaviour of GNU's cpio and is supported by the kernel initramfs extractor. Signed-off-by: Luciano Rocha <strange@nsk.no-ip.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Luciano Rocha · Linus Torvalds
1 parent 67d38229df
Showing 1 changed file with 86 additions and 36 deletions Side-by-side Diff
usr/gen_init_cpio.c
@@ -14,6 +14,7 @@
  * Original work by Jeff Garzik
  *
  * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
+ * Hard link support by Luciano Rocha
  */
  
 #define xstr(s) #s
  
  
  
@@ -286,16 +287,19 @@
 	return rc;
 }
  
-/* Not marked static to keep the compiler quiet, as no one uses this yet... */
 static int cpio_mkfile(const char *name, const char *location,
-			unsigned int mode, uid_t uid, gid_t gid)
+			unsigned int mode, uid_t uid, gid_t gid,
+			unsigned int nlinks)
 {
 	char s[256];
 	char *filebuf = NULL;
 	struct stat buf;
+	long size;
 	int file = -1;
 	int retval;
 	int rc = -1;
+	int namesize;
+	int i;
  
 	mode |= S_IFREG;
  
  
@@ -323,29 +327,41 @@
 		goto error;
 	}
  
-	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
-	       "%08X%08X%08X%08X%08X%08X%08X",
-		"070701",		/* magic */
-		ino++,			/* ino */
-		mode,			/* mode */
-		(long) uid,		/* uid */
-		(long) gid,		/* gid */
-		1,			/* nlink */
-		(long) buf.st_mtime,	/* mtime */
-		(int) buf.st_size,	/* filesize */
-		3,			/* major */
-		1,			/* minor */
-		0,			/* rmajor */
-		0,			/* rminor */
-		(unsigned)strlen(name) + 1,/* namesize */
-		0);			/* chksum */
-	push_hdr(s);
-	push_string(name);
-	push_pad();
+	size = 0;
+	for (i = 1; i <= nlinks; i++) {
+		/* data goes on last link */
+		if (i == nlinks) size = buf.st_size;
  
-	fwrite(filebuf, buf.st_size, 1, stdout);
-	offset += buf.st_size;
-	push_pad();
+		namesize = strlen(name) + 1;
+		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
+		       "%08lX%08X%08X%08X%08X%08X%08X",
+			"070701",		/* magic */
+			ino,			/* ino */
+			mode,			/* mode */
+			(long) uid,		/* uid */
+			(long) gid,		/* gid */
+			nlinks,			/* nlink */
+			(long) buf.st_mtime,	/* mtime */
+			size,			/* filesize */
+			3,			/* major */
+			1,			/* minor */
+			0,			/* rmajor */
+			0,			/* rminor */
+			namesize,		/* namesize */
+			0);			/* chksum */
+		push_hdr(s);
+		push_string(name);
+		push_pad();
+
+		if (size) {
+			fwrite(filebuf, size, 1, stdout);
+			offset += size;
+			push_pad();
+		}
+
+		name += namesize;
+	}
+	ino++;
 	rc = 0;
  
 error:
  
  
  
  
@@ -357,18 +373,51 @@
 static int cpio_mkfile_line(const char *line)
 {
 	char name[PATH_MAX + 1];
+	char *dname = NULL; /* malloc'ed buffer for hard links */
 	char location[PATH_MAX + 1];
 	unsigned int mode;
 	int uid;
 	int gid;
+	int nlinks = 1;
+	int end = 0, dname_len = 0;
 	int rc = -1;
  
-	if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, location, &mode, &uid, &gid)) {
+	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
+				"s %o %d %d %n",
+				name, location, &mode, &uid, &gid, &end)) {
 		fprintf(stderr, "Unrecognized file format '%s'", line);
 		goto fail;
 	}
-	rc = cpio_mkfile(name, location, mode, uid, gid);
+	if (end && isgraph(line[end])) {
+		int len;
+		int nend;
+
+		dname = malloc(strlen(line));
+		if (!dname) {
+			fprintf (stderr, "out of memory (%d)\n", dname_len);
+			goto fail;
+		}
+
+		dname_len = strlen(name) + 1;
+		memcpy(dname, name, dname_len);
+
+		do {
+			nend = 0;
+			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
+					name, &nend) < 1)
+				break;
+			len = strlen(name) + 1;
+			memcpy(dname + dname_len, name, len);
+			dname_len += len;
+			nlinks++;
+			end += nend;
+		} while (isgraph(line[end]));
+	} else {
+		dname = name;
+	}
+	rc = cpio_mkfile(dname, location, mode, uid, gid, nlinks);
  fail:
+	if (dname_len) free(dname);
 	return rc;
 }
  
  
@@ -381,22 +430,23 @@
 		"describe the files to be included in the initramfs archive:\n"
 		"\n"
 		"# a comment\n"
-		"file <name> <location> <mode> <uid> <gid>\n"
+		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
 		"dir <name> <mode> <uid> <gid>\n"
 		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
 		"slink <name> <target> <mode> <uid> <gid>\n"
 		"pipe <name> <mode> <uid> <gid>\n"
 		"sock <name> <mode> <uid> <gid>\n"
 		"\n"
-		"<name>      name of the file/dir/nod/etc in the archive\n"
-		"<location>  location of the file in the current filesystem\n"
-		"<target>    link target\n"
-		"<mode>      mode/permissions of the file\n"
-		"<uid>       user id (0=root)\n"
-		"<gid>       group id (0=root)\n"
-		"<dev_type>  device type (b=block, c=character)\n"
-		"<maj>       major number of nod\n"
-		"<min>       minor number of nod\n"
+		"<name>       name of the file/dir/nod/etc in the archive\n"
+		"<location>   location of the file in the current filesystem\n"
+		"<target>     link target\n"
+		"<mode>       mode/permissions of the file\n"
+		"<uid>        user id (0=root)\n"
+		"<gid>        group id (0=root)\n"
+		"<dev_type>   device type (b=block, c=character)\n"
+		"<maj>        major number of nod\n"
+		"<min>        minor number of nod\n"
+		"<hard links> space separated list of other links to file\n"
 		"\n"
 		"example:\n"
 		"# A simple initramfs\n"
...	...	@@ -14,6 +14,7 @@
14	14	* Original work by Jeff Garzik
15	15	*
16	16	* External file lists, symlink, pipe and fifo support by Thayne Harbaugh
	17	+ * Hard link support by Luciano Rocha
17	18	*/
18	19
19	20	#define xstr(s) #s
20	21
21	22
22	23
...	...	@@ -286,16 +287,19 @@
286	287	return rc;
287	288	}
288	289
289		-/* Not marked static to keep the compiler quiet, as no one uses this yet... */
290	290	static int cpio_mkfile(const char name, const char location,
291		- unsigned int mode, uid_t uid, gid_t gid)
	291	+ unsigned int mode, uid_t uid, gid_t gid,
	292	+ unsigned int nlinks)
292	293	{
293	294	char s[256];
294	295	char *filebuf = NULL;
295	296	struct stat buf;
	297	+ long size;
296	298	int file = -1;
297	299	int retval;
298	300	int rc = -1;
	301	+ int namesize;
	302	+ int i;
299	303
300	304	mode \|= S_IFREG;
301	305
302	306
...	...	@@ -323,29 +327,41 @@
323	327	goto error;
324	328	}
325	329
326		- sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
327		- "%08X%08X%08X%08X%08X%08X%08X",
328		- "070701", /* magic */
329		- ino++, /* ino */
330		- mode, /* mode */
331		- (long) uid, /* uid */
332		- (long) gid, /* gid */
333		- 1, /* nlink */
334		- (long) buf.st_mtime, /* mtime */
335		- (int) buf.st_size, /* filesize */
336		- 3, /* major */
337		- 1, /* minor */
338		- 0, /* rmajor */
339		- 0, /* rminor */
340		- (unsigned)strlen(name) + 1,/* namesize */
341		- 0); /* chksum */
342		- push_hdr(s);
343		- push_string(name);
344		- push_pad();
	330	+ size = 0;
	331	+ for (i = 1; i <= nlinks; i++) {
	332	+ /* data goes on last link */
	333	+ if (i == nlinks) size = buf.st_size;
345	334
346		- fwrite(filebuf, buf.st_size, 1, stdout);
347		- offset += buf.st_size;
348		- push_pad();
	335	+ namesize = strlen(name) + 1;
	336	+ sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	337	+ "%08lX%08X%08X%08X%08X%08X%08X",
	338	+ "070701", /* magic */
	339	+ ino, /* ino */
	340	+ mode, /* mode */
	341	+ (long) uid, /* uid */
	342	+ (long) gid, /* gid */
	343	+ nlinks, /* nlink */
	344	+ (long) buf.st_mtime, /* mtime */
	345	+ size, /* filesize */
	346	+ 3, /* major */
	347	+ 1, /* minor */
	348	+ 0, /* rmajor */
	349	+ 0, /* rminor */
	350	+ namesize, /* namesize */
	351	+ 0); /* chksum */
	352	+ push_hdr(s);
	353	+ push_string(name);
	354	+ push_pad();
	355	+
	356	+ if (size) {
	357	+ fwrite(filebuf, size, 1, stdout);
	358	+ offset += size;
	359	+ push_pad();
	360	+ }
	361	+
	362	+ name += namesize;
	363	+ }
	364	+ ino++;
349	365	rc = 0;
350	366
351	367	error:
352	368
353	369
354	370
355	371
...	...	@@ -357,18 +373,51 @@
357	373	static int cpio_mkfile_line(const char *line)
358	374	{
359	375	char name[PATH_MAX + 1];
	376	+ char dname = NULL; / malloc'ed buffer for hard links */
360	377	char location[PATH_MAX + 1];
361	378	unsigned int mode;
362	379	int uid;
363	380	int gid;
	381	+ int nlinks = 1;
	382	+ int end = 0, dname_len = 0;
364	383	int rc = -1;
365	384
366		- if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, location, &mode, &uid, &gid)) {
	385	+ if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
	386	+ "s %o %d %d %n",
	387	+ name, location, &mode, &uid, &gid, &end)) {
367	388	fprintf(stderr, "Unrecognized file format '%s'", line);
368	389	goto fail;
369	390	}
370		- rc = cpio_mkfile(name, location, mode, uid, gid);
	391	+ if (end && isgraph(line[end])) {
	392	+ int len;
	393	+ int nend;
	394	+
	395	+ dname = malloc(strlen(line));
	396	+ if (!dname) {
	397	+ fprintf (stderr, "out of memory (%d)\n", dname_len);
	398	+ goto fail;
	399	+ }
	400	+
	401	+ dname_len = strlen(name) + 1;
	402	+ memcpy(dname, name, dname_len);
	403	+
	404	+ do {
	405	+ nend = 0;
	406	+ if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
	407	+ name, &nend) < 1)
	408	+ break;
	409	+ len = strlen(name) + 1;
	410	+ memcpy(dname + dname_len, name, len);
	411	+ dname_len += len;
	412	+ nlinks++;
	413	+ end += nend;
	414	+ } while (isgraph(line[end]));
	415	+ } else {
	416	+ dname = name;
	417	+ }
	418	+ rc = cpio_mkfile(dname, location, mode, uid, gid, nlinks);
371	419	fail:
	420	+ if (dname_len) free(dname);
372	421	return rc;
373	422	}
374	423
375	424
...	...	@@ -381,22 +430,23 @@
381	430	"describe the files to be included in the initramfs archive:\n"
382	431	"\n"
383	432	"# a comment\n"
384		- "file <name> <location> <mode> <uid> <gid>\n"
	433	+ "file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
385	434	"dir <name> <mode> <uid> <gid>\n"
386	435	"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
387	436	"slink <name> <target> <mode> <uid> <gid>\n"
388	437	"pipe <name> <mode> <uid> <gid>\n"
389	438	"sock <name> <mode> <uid> <gid>\n"
390	439	"\n"
391		- "<name> name of the file/dir/nod/etc in the archive\n"
392		- "<location> location of the file in the current filesystem\n"
393		- "<target> link target\n"
394		- "<mode> mode/permissions of the file\n"
395		- "<uid> user id (0=root)\n"
396		- "<gid> group id (0=root)\n"
397		- "<dev_type> device type (b=block, c=character)\n"
398		- "<maj> major number of nod\n"
399		- "<min> minor number of nod\n"
	440	+ "<name> name of the file/dir/nod/etc in the archive\n"
	441	+ "<location> location of the file in the current filesystem\n"
	442	+ "<target> link target\n"
	443	+ "<mode> mode/permissions of the file\n"
	444	+ "<uid> user id (0=root)\n"
	445	+ "<gid> group id (0=root)\n"
	446	+ "<dev_type> device type (b=block, c=character)\n"
	447	+ "<maj> major number of nod\n"
	448	+ "<min> minor number of nod\n"
	449	+ "<hard links> space separated list of other links to file\n"
400	450	"\n"
401	451	"example:\n"
402	452	"# A simple initramfs\n"