[PATCH] gen_init_cpio symlink, pipe and socket support

This patch makes gen_init_cpio more complete by adding symlink, pipe and
socket support.  It updates scripts/gen_initramfs_list.sh to support the
new types.  The patch applies to the recent mm series that already have the
updated gen_init_cpio and gen_initramfs_list.sh.

From: William Lee Irwin III <wli@holomorphy.com>

The rest of gen_init_cpio.c seems to cast the result of strlen() to handle
this situation, so this patch follows suit while killing off size_t -related
printk() warnings.

Signed-off-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/Documentation/early-userspace/README b/Documentation/early-userspace/README
index 7d56612..77eaa58 100644 (file)
--- a/Documentation/early-userspace/README
+++ b/Documentation/early-userspace/README
@@ -1,7 +1,7 @@
 Early userspace support
 =======================
 
-Last update: 2003-08-21
+Last update: 2004-11-12
 
 
 "Early userspace" is a set of libraries and programs that provide
@@ -17,14 +17,22 @@ It consists of several major infrastructure components:
 - initramfs, a chunk of code that unpacks the compressed cpio image
   midway through the kernel boot process.
 - klibc, a userspace C library, currently packaged separately, that is
-  optimised for correctness and small size.
+  optimized for correctness and small size.
 
 The cpio file format used by initramfs is the "newc" (aka "cpio -c")
-format, and is documented in the file "buffer-format.txt".  If you
-want to generate your own cpio files directly instead of hacking on
-gen_init_cpio, you will need to short-circuit the build process in
-usr/ so that gen_init_cpio does not get run, then simply pop your own
-initramfs_data.cpio.gz file into place.
+format, and is documented in the file "buffer-format.txt".  There are
+three ways to add an early userspace filesystem:
+
+1) Put your gzip'ed cpio in usr/initramfs_data.cpio.gz.
+
+2) Set CONFIG_INITRAMFS_SOURCE to the filename of a gen_init_cpio
+input file.  This provides the most flexibility and allows creation of
+archives with files not owned by the build user.  This means that an
+unprivileged user can create an early userspace with files owned by
+root.
+
+3) Set CONFIG_INITRAMFS_SOURCE to point to a directory containing the
+files for your filesystem.
 
 
 Where's this all leading?

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index f4ed730..12b66b9 100644 (file)
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -363,24 +363,9 @@ config INITRAMFS_SOURCE
        default ""
        help
          This can be set to either a directory containing files, etc to be
-         included in the initramfs archive, or a file containing newline
-         separated entries.
-
-         If it is a file, it should be in the following format:
-           # a comment
-           file <name> <location> <mode> <uid> <gid>
-           dir <name> <mode> <uid> <gid>
-           nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>
-
-         Where:
-           <name>      name of the file/dir/nod in the archive
-           <location>  location of the file in the current filesystem
-           <mode>      mode/permissions of the file
-           <uid>       user id (0=root)
-           <gid>       group id (0=root)
-           <dev_type>  device type (b=block, c=character)
-           <maj>       major number of nod
-           <min>       minor number of nod
+         included in the initramfs archive, or a file containing  entries
+         according to the format described by the "usr/gen_init_cpio"
+         program in the kernel tree.
 
          If you are not sure, leave it blank.
 

diff --git a/scripts/gen_initramfs_list.sh b/scripts/gen_initramfs_list.sh
index 2a697c3..79ccbd7 100644 (file)
--- a/scripts/gen_initramfs_list.sh
+++ b/scripts/gen_initramfs_list.sh
@@ -9,8 +9,6 @@
 #
 # The output is suitable for gen_init_cpio as found in usr/Makefile.
 #
-# TODO:  Add support for symlinks, sockets and pipes when gen_init_cpio
-#        supports them.
 
 simple_initramfs() {
        cat <<-EOF
@@ -25,12 +23,19 @@ simple_initramfs() {
 filetype() {
        local argv1="$1"
 
-       if [ -f "${argv1}" ]; then
+       # symlink test must come before file test
+       if [ -L "${argv1}" ]; then
+               echo "slink"
+       elif [ -f "${argv1}" ]; then
                echo "file"
        elif [ -d "${argv1}" ]; then
                echo "dir"
        elif [ -b "${argv1}" -o -c "${argv1}" ]; then
                echo "nod"
+       elif [ -p "${argv1}" ]; then
+               echo "pipe"
+       elif [ -S "${argv1}" ]; then
+               echo "sock"
        else
                echo "invalid"
        fi
@@ -52,6 +57,8 @@ print_mtime() {
 parse() {
        local location="$1"
        local name="${location/${srcdir}//}"
+       # change '//' into '/'
+       name="${name//\/\///}"
        local mode="$2"
        local uid="$3"
        local gid="$4"
@@ -79,6 +86,11 @@ parse() {
                        fi
                        str="${ftype} ${name} ${str} ${dev_type} ${maj} ${min}"
                        ;;
+               "slink")
+                       local target=$(LC_ALL=C ls -l "${location}" | \
+                                       gawk '{print $11}')
+                       str="${ftype} ${name} ${target} ${str}"
+                       ;;
                *)
                        str="${ftype} ${name} ${str}"
                        ;;

diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c
index 7672fbb..10bb8f8 100644 (file)
--- a/usr/gen_init_cpio.c
+++ b/usr/gen_init_cpio.c
@@ -10,13 +10,19 @@
 #include <ctype.h>
 #include <limits.h>
 
+/*
+ * Original work by Jeff Garzik
+ *
+ * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
+ */
+
 #define xstr(s) #s
 #define str(s) xstr(s)
 
 static unsigned int offset;
 static unsigned int ino = 721;
 
-struct file_type {
+struct file_handler {
        const char *type;
        int (*handler)(const char *line);
 };
@@ -80,7 +86,7 @@ static void cpio_trailer(void)
                0,                      /* minor */
                0,                      /* rmajor */
                0,                      /* rminor */
-               (unsigned)strlen(name) + 1, /* namesize */
+               (unsigned)strlen(name)+1, /* namesize */
                0);                     /* chksum */
        push_hdr(s);
        push_rest(name);
@@ -91,7 +97,55 @@ static void cpio_trailer(void)
        }
 }
 
-static int cpio_mkdir(const char *name, unsigned int mode,
+static int cpio_mkslink(const char *name, const char *target,
+                        unsigned int mode, uid_t uid, gid_t gid)
+{
+       char s[256];
+       time_t mtime = time(NULL);
+
+       sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
+              "%08X%08X%08X%08X%08X%08X%08X",
+               "070701",               /* magic */
+               ino++,                  /* ino */
+               S_IFLNK | mode,         /* mode */
+               (long) uid,             /* uid */
+               (long) gid,             /* gid */
+               1,                      /* nlink */
+               (long) mtime,           /* mtime */
+               (unsigned)strlen(target)+1, /* filesize */
+               3,                      /* major */
+               1,                      /* minor */
+               0,                      /* rmajor */
+               0,                      /* rminor */
+               (unsigned)strlen(name) + 1,/* namesize */
+               0);                     /* chksum */
+       push_hdr(s);
+       push_string(name);
+       push_pad();
+       push_string(target);
+       push_pad();
+       return 0;
+}
+
+static int cpio_mkslink_line(const char *line)
+{
+       char name[PATH_MAX + 1];
+       char target[PATH_MAX + 1];
+       unsigned int mode;
+       int uid;
+       int gid;
+       int rc = -1;
+
+       if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
+               fprintf(stderr, "Unrecognized dir format '%s'", line);
+               goto fail;
+       }
+       rc = cpio_mkslink(name, target, mode, uid, gid);
+ fail:
+       return rc;
+}
+
+static int cpio_mkgeneric(const char *name, unsigned int mode,
                       uid_t uid, gid_t gid)
 {
        char s[256];
@@ -101,7 +155,7 @@ static int cpio_mkdir(const char *name, unsigned int mode,
               "%08X%08X%08X%08X%08X%08X%08X",
                "070701",               /* magic */
                ino++,                  /* ino */
-               S_IFDIR | mode,         /* mode */
+               mode,                   /* mode */
                (long) uid,             /* uid */
                (long) gid,             /* gid */
                2,                      /* nlink */
@@ -118,7 +172,33 @@ static int cpio_mkdir(const char *name, unsigned int mode,
        return 0;
 }
 
-static int cpio_mkdir_line(const char *line)
+enum generic_types {
+       GT_DIR,
+       GT_PIPE,
+       GT_SOCK
+};
+
+struct generic_type {
+       const char *type;
+       mode_t mode;
+};
+
+static struct generic_type generic_type_table[] = {
+       [GT_DIR] = {
+               .type = "dir",
+               .mode = S_IFDIR
+       },
+       [GT_PIPE] = {
+               .type = "pipe",
+               .mode = S_IFIFO
+       },
+       [GT_SOCK] = {
+               .type = "sock",
+               .mode = S_IFSOCK
+       }
+};
+
+static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
 {
        char name[PATH_MAX + 1];
        unsigned int mode;
@@ -127,14 +207,31 @@ static int cpio_mkdir_line(const char *line)
        int rc = -1;
 
        if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
-               fprintf(stderr, "Unrecognized dir format '%s'", line);
+               fprintf(stderr, "Unrecognized %s format '%s'",
+                       line, generic_type_table[gt].type);
                goto fail;
        }
-       rc = cpio_mkdir(name, mode, uid, gid);
+       mode |= generic_type_table[gt].mode;
+       rc = cpio_mkgeneric(name, mode, uid, gid);
  fail:
        return rc;
 }
 
+static int cpio_mkdir_line(const char *line)
+{
+       return cpio_mkgeneric_line(line, GT_DIR);
+}
+
+static int cpio_mkpipe_line(const char *line)
+{
+       return cpio_mkgeneric_line(line, GT_PIPE);
+}
+
+static int cpio_mksock_line(const char *line)
+{
+       return cpio_mkgeneric_line(line, GT_SOCK);
+}
+
 static int cpio_mknod(const char *name, unsigned int mode,
                       uid_t uid, gid_t gid, char dev_type,
                       unsigned int maj, unsigned int min)
@@ -286,12 +383,16 @@ void usage(const char *prog)
                "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>\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 in the archive\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"
@@ -309,7 +410,7 @@ void usage(const char *prog)
                prog);
 }
 
-struct file_type file_type_table[] = {
+struct file_handler file_handler_table[] = {
        {
                .type    = "file",
                .handler = cpio_mkfile_line,
@@ -320,6 +421,15 @@ struct file_type file_type_table[] = {
                .type    = "dir",
                .handler = cpio_mkdir_line,
        }, {
+               .type    = "slink",
+               .handler = cpio_mkslink_line,
+       }, {
+               .type    = "pipe",
+               .handler = cpio_mkpipe_line,
+       }, {
+               .type    = "sock",
+               .handler = cpio_mksock_line,
+       }, {
                .type    = NULL,
                .handler = NULL,
        }
@@ -382,10 +492,10 @@ int main (int argc, char *argv[])
                        ec = -1;
                }
 
-               for (type_idx = 0; file_type_table[type_idx].type; type_idx++) {
+               for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
                        int rc;
-                       if (! strcmp(line, file_type_table[type_idx].type)) {
-                               if ((rc = file_type_table[type_idx].handler(args))) {
+                       if (! strcmp(line, file_handler_table[type_idx].type)) {
+                               if ((rc = file_handler_table[type_idx].handler(args))) {
                                        ec = rc;
                                        fprintf(stderr, " line %d\n", line_nr);
                                }
@@ -393,7 +503,7 @@ int main (int argc, char *argv[])
                        }
                }
 
-               if (NULL == file_type_table[type_idx].type) {
+               if (NULL == file_handler_table[type_idx].type) {
                        fprintf(stderr, "unknown file type line %d: '%s'\n",
                                line_nr, line);
                }