X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=helper%2Fext2.c;h=2fc8036e00eccc850d05766496272ec34501ce0d;hb=cf29103041581a1d71444f978ad4f6ad69b63033;hp=29002218872e0a127aee08e74a2f706d6b011fbe;hpb=f0893a62d46605305ae14baba6cae3eebffc6005;p=febootstrap.git

diff --git a/helper/ext2.c b/helper/ext2.c
index 2900221..2fc8036 100644
--- a/helper/ext2.c
+++ b/helper/ext2.c
@@ -21,26 +21,481 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <limits.h>
 #include <sys/stat.h>
 #include <assert.h>
 
 #include "error.h"
 #include "fts_.h"
+#include "xvasprintf.h"
 
 #include "helper.h"
+#include "ext2internal.h"
+
+ext2_filsys fs;
+
+/* The ext2 image that we build always has a fixed size, and we 'hope'
+ * that the files fit in (otherwise we'll get an error).  Note that
+ * the file is sparsely allocated.
+ *
+ * The downside of allocating a very large initial disk is that the
+ * fixed overhead of ext2 is larger (since ext2 calculates it based on
+ * the size of the disk).  For a 1GB disk the overhead is
+ * approximately 16MB.
+ *
+ * In future, make this configurable, or determine it from the input
+ * files (XXX).
+ */
+#define APPLIANCE_SIZE (1024*1024*1024)
 
 static void
-ext2_start (const char *appliance,
+ext2_start (const char *hostcpu, const char *appliance,
             const char *modpath, const char *initrd)
 {
-  abort ();
+  initialize_ext2_error_table ();
+
+  /* Make the initrd. */
+  ext2_make_initrd (modpath, initrd);
+
+  /* Make the appliance sparse image. */
+  int fd = open (appliance, O_WRONLY | O_CREAT | O_TRUNC | O_NOCTTY, 0644);
+  if (fd == -1)
+    error (EXIT_FAILURE, errno, "open: %s", appliance);
+
+  if (lseek (fd, APPLIANCE_SIZE - 1, SEEK_SET) == -1)
+    error (EXIT_FAILURE, errno, "lseek");
+
+  char c = 0;
+  if (write (fd, &c, 1) != 1)
+    error (EXIT_FAILURE, errno, "write");
+
+  if (close (fd) == -1)
+    error (EXIT_FAILURE, errno, "close");
+
+  /* Run mke2fs on the file.
+   * XXX Quoting, but this string doesn't come from an untrusted source.
+   */
+  char *cmd = xasprintf ("%s -t ext2 -F%s '%s'",
+                         MKE2FS,
+                         verbose >= 2 ? "" : "q",
+                         appliance);
+  int r = system (cmd);
+  if (r == -1 || WEXITSTATUS (r) != 0)
+    error (EXIT_FAILURE, 0, "%s: failed", cmd);
+  free (cmd);
+
+  if (verbose)
+    print_timestamped_message ("finished mke2fs");
+
+  /* Open the filesystem. */
+  errcode_t err =
+    ext2fs_open (appliance, EXT2_FLAG_RW, 0, 0, unix_io_manager, &fs);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_open: %s", error_message (err));
+
+  /* Bitmaps are not loaded by default, so load them.  ext2fs_close will
+   * write out any changes.
+   */
+  err = ext2fs_read_bitmaps (fs);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_read_bitmaps: %s", error_message (err));
+}
+
+static void
+ext2_end (void)
+{
+  /* Write out changes and close. */
+  errcode_t err = ext2fs_close (fs);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_close: %s", error_message (err));
+}
+
+void
+ext2_mkdir (ext2_ino_t dir_ino, const char *dirname, const char *basename,
+            mode_t mode, uid_t uid, gid_t gid,
+            time_t ctime, time_t atime, time_t mtime)
+{
+  errcode_t err;
+
+  mode = LINUX_S_IFDIR | (mode & 0777);
+
+  /* Does the directory exist?  This is legitimate: we just skip
+   * this case.
+   */
+  ext2_ino_t ino;
+  err = ext2fs_namei (fs, EXT2_ROOT_INO, dir_ino, basename, &ino);
+  if (err == 0)
+    return; /* skip */
+
+  /* Otherwise, create it. */
+  err = ext2fs_new_inode (fs, dir_ino, mode, 0, &ino);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_new_inode: %s", error_message (err));
+
+ try_again:
+  err = ext2fs_mkdir (fs, dir_ino, ino, basename);
+  if (err != 0) {
+    /* See: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=217892 */
+    if (err == EXT2_ET_DIR_NO_SPACE) {
+      err = ext2fs_expand_dir (fs, dir_ino);
+      if (err)
+        error (EXIT_FAILURE, 0, "ext2fs_expand_dir: %s/%s: %s",
+               dirname, basename, error_message (err));
+      goto try_again;
+    } else
+      error (EXIT_FAILURE, 0, "ext2fs_mkdir: %s/%s: %s",
+             dirname, basename, error_message (err));
+  }
+
+  /* Copy the final permissions, UID etc. to the inode. */
+  struct ext2_inode inode;
+  err = ext2fs_read_inode (fs, ino, &inode);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_read_inode: %s", error_message (err));
+  inode.i_mode = mode;
+  inode.i_uid = uid;
+  inode.i_gid = gid;
+  inode.i_ctime = ctime;
+  inode.i_atime = atime;
+  inode.i_mtime = mtime;
+  err = ext2fs_write_inode (fs, ino, &inode);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_write_inode: %s", error_message (err));
+}
+
+void
+ext2_empty_inode (ext2_ino_t dir_ino, const char *dirname, const char *basename,
+                  mode_t mode, uid_t uid, gid_t gid,
+                  time_t ctime, time_t atime, time_t mtime,
+                  int major, int minor, int dir_ft, ext2_ino_t *ino_ret)
+{
+  errcode_t err;
+  struct ext2_inode inode;
+  ext2_ino_t ino;
+
+  err = ext2fs_new_inode (fs, dir_ino, mode, 0, &ino);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_new_inode: %s", error_message (err));
+
+  memset (&inode, 0, sizeof inode);
+  inode.i_mode = mode;
+  inode.i_uid = uid;
+  inode.i_gid = gid;
+  inode.i_blocks = 0;
+  inode.i_links_count = 1;
+  inode.i_ctime = ctime;
+  inode.i_atime = atime;
+  inode.i_mtime = mtime;
+  inode.i_size = 0;
+  inode.i_block[0] = (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
+
+  err = ext2fs_write_new_inode (fs, ino, &inode);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_write_inode: %s", error_message (err));
+
+  ext2_link (dir_ino, basename, ino, dir_ft);
+
+  ext2fs_inode_alloc_stats2 (fs, ino, 1, 0);
+
+  if (ino_ret)
+    *ino_ret = ino;
+}
+
+/* You must create the file first with ext2_empty_inode. */
+void
+ext2_write_file (ext2_ino_t ino, const char *buf, size_t size)
+{
+  errcode_t err;
+  ext2_file_t file;
+  err = ext2fs_file_open2 (fs, ino, NULL, EXT2_FILE_WRITE, &file);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_file_open2: %s", error_message (err));
+
+  /* ext2fs_file_write cannot deal with partial writes.  You have
+   * to write the entire file in a single call.
+   */
+  unsigned int written;
+  err = ext2fs_file_write (file, buf, size, &written);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_file_write: %s", error_message (err));
+  if ((size_t) written != size)
+    error (EXIT_FAILURE, 0,
+           "ext2fs_file_write: size = %zu != written = %u\n",
+           size, written);
+
+  err = ext2fs_file_flush (file);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_file_flush: %s", error_message (err));
+  err = ext2fs_file_close (file);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_file_close: %s", error_message (err));
+
+  /* Update the true size in the inode. */
+  struct ext2_inode inode;
+  err = ext2fs_read_inode (fs, ino, &inode);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_read_inode: %s", error_message (err));
+  inode.i_size = size;
+  err = ext2fs_write_inode (fs, ino, &inode);
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_write_inode: %s", error_message (err));
+}
+
+/* This is just a wrapper around ext2fs_link which calls
+ * ext2fs_expand_dir as necessary if the directory fills up.  See
+ * definition of expand_dir in the sources of debugfs.
+ */
+void
+ext2_link (ext2_ino_t dir_ino, const char *basename, ext2_ino_t ino, int dir_ft)
+{
+  errcode_t err;
+
+ again:
+  err = ext2fs_link (fs, dir_ino, basename, ino, dir_ft);
+
+  if (err == EXT2_ET_DIR_NO_SPACE) {
+    err = ext2fs_expand_dir (fs, dir_ino);
+    if (err != 0)
+      error (EXIT_FAILURE, 0, "ext2_link: ext2fs_expand_dir: %s: %s",
+             basename, error_message (err));
+    goto again;
+  }
+
+  if (err != 0)
+    error (EXIT_FAILURE, 0, "ext2fs_link: %s: %s",
+             basename, error_message (err));
+}
+
+static int
+release_block (ext2_filsys fs, blk_t *blocknr,
+                int blockcnt, void *private)
+{
+  blk_t block;
+
+  block = *blocknr;
+  ext2fs_block_alloc_stats (fs, block, -1);
+  return 0;
+}
+
+/* unlink or rmdir path, if it exists. */
+void
+ext2_clean_path (ext2_ino_t dir_ino,
+                 const char *dirname, const char *basename,
+                 int isdir)
+{
+  errcode_t err;
+
+  ext2_ino_t ino;
+  err = ext2fs_lookup (fs, dir_ino, basename, strlen (basename),
+                       NULL, &ino);
+  if (err == EXT2_ET_FILE_NOT_FOUND)
+    return;
+
+  if (!isdir) {
+    struct ext2_inode inode;
+    err = ext2fs_read_inode (fs, ino, &inode);
+    if (err != 0)
+      error (EXIT_FAILURE, 0, "ext2fs_read_inode: %s", error_message (err));
+    inode.i_links_count--;
+    err = ext2fs_write_inode (fs, ino, &inode);
+    if (err != 0)
+      error (EXIT_FAILURE, 0, "ext2fs_write_inode: %s", error_message (err));
+
+    err = ext2fs_unlink (fs, dir_ino, basename, 0, 0);
+    if (err != 0)
+      error (EXIT_FAILURE, 0, "ext2fs_unlink_inode: %s", error_message (err));
+
+    if (inode.i_links_count == 0) {
+      inode.i_dtime = time (NULL);
+      err = ext2fs_write_inode (fs, ino, &inode);
+      if (err != 0)
+        error (EXIT_FAILURE, 0, "ext2fs_write_inode: %s", error_message (err));
+
+      if (ext2fs_inode_has_valid_blocks (&inode)) {
+	int flags = 0;
+	/* From the docs: "BLOCK_FLAG_READ_ONLY is a promise by the
+	 * caller that it will not modify returned block number."
+	 * RHEL 5 does not have this flag, so just omit it if it is
+	 * not defined.
+	 */
+#ifdef BLOCK_FLAG_READ_ONLY
+	flags |= BLOCK_FLAG_READ_ONLY;
+#endif
+        ext2fs_block_iterate (fs, ino, flags, NULL,
+                              release_block, NULL);
+      }
+
+      ext2fs_inode_alloc_stats2 (fs, ino, -1, isdir);
+    }
+  }
+  /* else it's a directory, what to do? XXX */
+}
+
+/* Read in the whole file into memory.  Check the size is still 'size'. */
+static char *
+read_whole_file (const char *filename, size_t size)
+{
+  char *buf = malloc (size);
+  if (buf == NULL)
+    error (EXIT_FAILURE, errno, "malloc");
+
+  int fd = open (filename, O_RDONLY);
+  if (fd == -1)
+    error (EXIT_FAILURE, errno, "open: %s", filename);
+
+  size_t n = 0;
+  char *p = buf;
+
+  while (n < size) {
+    ssize_t r = read (fd, p, size - n);
+    if (r == -1)
+      error (EXIT_FAILURE, errno, "read: %s", filename);
+    if (r == 0)
+      error (EXIT_FAILURE, 0,
+             "error: file has changed size unexpectedly: %s", filename);
+    n += r;
+    p += r;
+  }
+
+  if (close (fd) == -1)
+    error (EXIT_FAILURE, errno, "close: %s", filename);
+
+  return buf;
+}
+
+/* Add a file (or directory etc) from the host. */
+static void
+ext2_file_stat (const char *orig_filename, const struct stat *statbuf)
+{
+  errcode_t err;
+
+  if (verbose >= 2)
+    fprintf (stderr, "ext2_file_stat %s 0%o\n",
+             orig_filename, statbuf->st_mode);
+
+  /* Sanity check the path.  These rules are always true for the paths
+   * passed to us here from the appliance layer.  The assertions just
+   * verify that the rules haven't changed.
+   */
+  size_t n = strlen (orig_filename);
+  assert (n <= PATH_MAX);
+  assert (n > 0);
+  assert (orig_filename[0] == '/'); /* always absolute path */
+  assert (n == 1 || orig_filename[n-1] != '/'); /* no trailing slash */
+
+  /* Don't make the root directory, it always exists.  This simplifies
+   * the code that follows.
+   */
+  if (n == 1) return;
+
+  const char *dirname, *basename;
+  const char *p = strrchr (orig_filename, '/');
+  ext2_ino_t dir_ino;
+  if (orig_filename == p) {     /* "/foo" */
+    dirname = "/";
+    basename = orig_filename+1;
+    dir_ino = EXT2_ROOT_INO;
+  } else {                      /* "/foo/bar" */
+    dirname = strndup (orig_filename, p-orig_filename);
+    basename = p+1;
+
+    /* Look up the parent directory. */
+    err = ext2fs_namei (fs, EXT2_ROOT_INO, EXT2_ROOT_INO, dirname, &dir_ino);
+    if (err != 0)
+      error (EXIT_FAILURE, 0, "ext2: parent directory not found: %s: %s",
+             dirname, error_message (err));
+  }
+
+  ext2_clean_path (dir_ino, dirname, basename, S_ISDIR (statbuf->st_mode));
+
+  int dir_ft;
+
+  /* Create regular file. */
+  if (S_ISREG (statbuf->st_mode)) {
+    /* XXX Hard links get duplicated here. */
+    ext2_ino_t ino;
+    ext2_empty_inode (dir_ino, dirname, basename,
+                      statbuf->st_mode, statbuf->st_uid, statbuf->st_gid,
+                      statbuf->st_ctime, statbuf->st_atime, statbuf->st_mtime,
+                      0, 0, EXT2_FT_REG_FILE, &ino);
+
+    if (statbuf->st_size > 0) {
+      char *buf = read_whole_file (orig_filename, statbuf->st_size);
+      ext2_write_file (ino, buf, statbuf->st_size);
+      free (buf);
+    }
+  }
+  /* Create a symlink. */
+  else if (S_ISLNK (statbuf->st_mode)) {
+    ext2_ino_t ino;
+    ext2_empty_inode (dir_ino, dirname, basename,
+                      statbuf->st_mode, statbuf->st_uid, statbuf->st_gid,
+                      statbuf->st_ctime, statbuf->st_atime, statbuf->st_mtime,
+                      0, 0, EXT2_FT_SYMLINK, &ino);
+
+    char buf[PATH_MAX+1];
+    ssize_t r = readlink (orig_filename, buf, sizeof buf);
+    if (r == -1)
+      error (EXIT_FAILURE, errno, "readlink: %s", orig_filename);
+    ext2_write_file (ino, buf, r);
+  }
+  /* Create directory. */
+  else if (S_ISDIR (statbuf->st_mode))
+    ext2_mkdir (dir_ino, dirname, basename,
+                statbuf->st_mode, statbuf->st_uid, statbuf->st_gid,
+                statbuf->st_ctime, statbuf->st_atime, statbuf->st_mtime);
+  /* Create a special file. */
+  else if (S_ISBLK (statbuf->st_mode)) {
+    dir_ft = EXT2_FT_BLKDEV;
+    goto make_special;
+  }
+  else if (S_ISCHR (statbuf->st_mode)) {
+    dir_ft = EXT2_FT_CHRDEV;
+    goto make_special;
+  } else if (S_ISFIFO (statbuf->st_mode)) {
+    dir_ft = EXT2_FT_FIFO;
+    goto make_special;
+  } else if (S_ISSOCK (statbuf->st_mode)) {
+    dir_ft = EXT2_FT_SOCK;
+  make_special:
+    ext2_empty_inode (dir_ino, dirname, basename,
+                      statbuf->st_mode, statbuf->st_uid, statbuf->st_gid,
+                      statbuf->st_ctime, statbuf->st_atime, statbuf->st_mtime,
+                      major (statbuf->st_rdev), minor (statbuf->st_rdev),
+                      dir_ft, NULL);
+  }
+}
+
+static void
+ext2_file (const char *filename)
+{
+  struct stat statbuf;
+
+  if (lstat (filename, &statbuf) == -1)
+    error (EXIT_FAILURE, errno, "lstat: %s", filename);
+  ext2_file_stat (filename, &statbuf);
+}
+
+/* In theory this could be optimized to avoid a namei lookup, but
+ * it probably wouldn't make much difference.
+ */
+static void
+ext2_fts_entry (FTSENT *entry)
+{
+  if (entry->fts_info & FTS_NS || entry->fts_info & FTS_NSOK)
+    ext2_file (entry->fts_path);
+  else
+    ext2_file_stat (entry->fts_path, entry->fts_statp);
 }
 
 struct writer ext2_writer = {
   .wr_start = ext2_start,
-  /* .wr_end = ,
-  .wr_file = ,
-  .wr_file_stat = ,
-  .wr_fts_entry = ,
-  .wr_cpio_file = , */
+  .wr_end = ext2_end,
+  .wr_file = ext2_file,
+  .wr_file_stat = ext2_file_stat,
+  .wr_fts_entry = ext2_fts_entry,
+  .wr_cpio_file = ext2_cpio_file,
 };