New directory tmpfs, in-core filesystem based on libdiskfs

1 files changed, 288 insertions, 0 deletions

diff --git a/tmpfs/tmpfs.c b/tmpfs/tmpfs.c
new file mode 100644
index 00000000..1df0e04b
--- /dev/null
+++ b/tmpfs/tmpfs.c
@@ -0,0 +1,288 @@
+/* Main program and global state for tmpfs.
+   Copyright (C) 2000 Free Software Foundation, Inc.
+
+This file is part of the GNU Hurd.
+
+The GNU Hurd is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+The GNU Hurd is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with the GNU Hurd; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "tmpfs.h"
+#include <limits.h>
+#include <version.h>
+
+char *diskfs_server_name = "tmpfs";
+char *diskfs_server_version = HURD_VERSION;
+char *diskfs_disk_name = "swap";
+
+/* We ain't got to show you no stinkin' sync'ing.  */
+int diskfs_default_sync_interval = 0;
+
+/* We must supply some claimed limits, though we don't impose any new ones.  */
+int diskfs_link_max = (1ULL << (sizeof (nlink_t) * CHAR_BIT)) - 1;
+int diskfs_name_max = 255;	/* dirent d_namlen limit */
+int diskfs_maxsymlinks = 8;
+
+/* Yeah, baby, we do it all!  */
+int diskfs_shortcut_symlink = 1;
+int diskfs_shortcurt_chrdev = 1;
+int diskfs_shortcurt_blkdev = 1;
+int diskfs_shortcurt_fifo = 1;
+int diskfs_shortcurt_ifsock = 1;
+
+struct node *diskfs_root_node;
+
+
+error_t
+diskfs_set_statfs (struct statfs *st)
+{
+  fsblkcnt_t pages;
+
+  st->f_type = FSTYPE_MEMFS;
+  st->f_fsid = getpid ();
+
+  st->f_bsize = vm_page_size;
+  st->f_blocks = tmpfs_page_limit;
+
+  spin_lock (&diskfs_node_refcnt_lock);
+  st->f_files = num_files;
+  pages = round_page (tmpfs_space_used) / vm_page_size;
+  spin_unlock (&diskfs_node_refcnt_lock);
+
+  st->f_bfree = pages < tmpfs_page_limit ? tmpfs_page_limit - pages : 0;
+  st->f_bavail = st->f_bfree;
+  st->f_ffree = st->f_bavail / sizeof (struct disknode); /* Well, sort of.  */
+
+  return 0;
+}
+
+
+error_t
+diskfs_set_hypermetadata (int wait, int clean)
+{
+  /* All the state always just lives in core, so we have nothing to do.  */
+  return 0;
+}
+
+void
+diskfs_sync_everything (int wait)
+{
+}
+
+error_t
+diskfs_reload_global_state ()
+{
+  return 0;
+}
+
+
+
+/* Parse a command line option.  */
+static error_t
+parse_opt (int key, char *arg, struct argp_state *state)
+{
+  /* We save our parsed values in this structure, hung off STATE->hook.
+     Only after parsing all options successfully will we use these values.  */
+  struct
+  {
+    off_t size;
+  } *values = state->hook;
+
+  switch (key)
+    {
+    case ARGP_KEY_INIT:
+      state->child_inputs[0] = state->input;
+      values = malloc (sizeof *values);
+      if (values == 0)
+	return ENOMEM;
+      state->hook = values;
+      bzero (values, sizeof *values);
+      break;
+
+    case ARGP_KEY_NO_ARGS:
+      argp_error (state, "must supply maximum size");
+      return EINVAL;
+
+    case ARGP_KEY_ARGS:
+      if (state->argv[state->next + 1] != 0)
+	{
+	  argp_error (state, "too many arguments");
+	  return EINVAL;
+	}
+      else
+	{
+	  char *end = NULL;
+	  intmax_t size = strtoimax (state->argv[state->next], 0, &end);
+	  if (end == NULL || end == arg)
+	    {
+	      argp_error (state, "argument must be a number");
+	      return EINVAL;
+	    }
+	  if (size < 0)
+	    {
+	      argp_error (state, "negative size not meaningful");
+	      return EINVAL;
+	    }
+	  switch (*end)
+	    {
+	    case 'g':
+	    case 'G':
+	      size <<= 10;
+	    case 'm':
+	    case 'M':
+	      size <<= 10;
+	    case 'k':
+	    case 'K':
+	      size <<= 10;
+	      break;
+	    }
+	  size = (off_t) size;
+	  if (size < 0)
+	    {
+	      argp_error (state, "size too large");
+	      return EINVAL;
+	    }
+	  values->size = size;
+	}
+      break;
+
+    case ARGP_KEY_SUCCESS:
+      /* All options parse successfully, so implement ours if possible.  */
+      tmpfs_page_limit = values->size / vm_page_size;
+      break;
+
+    default:
+      return ARGP_ERR_UNKNOWN;
+    }
+  return 0;
+}
+
+/* Override the standard diskfs routine so we can add our own output.  */
+error_t
+diskfs_append_args (char **argz, unsigned *argz_len)
+{
+  error_t err;
+
+  /* Get the standard things.  */
+  err = diskfs_append_std_options (argz, argz_len);
+
+  if (!err)
+    {
+      off_t lim = tmpfs_page_limit * vm_page_size;
+      char buf[100], sfx;
+#define S(n, c) if ((lim & ((1 << n) - 1)) == 0) sfx = c, lim >>= n
+      S (30, 'G'); else S (20, 'M'); else S (10, 'K'); else sfx = '\0';
+#undef S
+      snprintf (buf, sizeof buf, "%ld%c", lim, sfx);
+      err = argz_add (argz, argz_len, buf);
+    }
+
+  return err;
+}
+
+/* Add our startup arguments to the standard diskfs set.  */
+static const struct argp_child startup_children[] =
+  {{&diskfs_startup_argp}, {0}};
+static struct argp startup_argp = {0, parse_opt, "MAX-BYTES", "\
+\v\
+MAX-BYTES may be followed by k or K for kilobytes,\n\
+m or M for megabytes, g or G for gigabytes.",
+				   startup_children};
+
+/* Similarly at runtime.  */
+static const struct argp_child runtime_children[] =
+  {{&diskfs_std_runtime_argp}, {0}};
+static struct argp runtime_argp = {0, parse_opt, 0, 0, runtime_children};
+
+struct argp *diskfs_runtime_argp = (struct argp *)&runtime_argp;
+
+
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  mach_port_t bootstrap, realnode, host_priv;
+  struct stat st;
+
+  err = argp_parse (&startup_argp, argc, argv, ARGP_IN_ORDER, NULL, NULL);
+  assert_perror (err);
+
+  task_get_bootstrap_port (mach_task_self (), &bootstrap);
+  if (bootstrap == MACH_PORT_NULL)
+    error (2, 0, "Must be started as a translator");
+
+  /* Get our port to the default pager.  Without that,
+     we have no place to put file contents.  */
+  err = get_privileged_ports (&host_priv, NULL);
+  if (err)
+    error (0, err, "Cannot get host privileged port");
+  else
+    {
+      err = vm_set_default_memory_manager (host, &default_pager);
+      mach_port_deallocate (mach_task_self (), host);
+      if (err)
+	error (0, err, "Cannot get default pager port");
+    }
+  if (default_pager == MACH_PORT_NULL)
+    error (0, 0, "files cannot have contents with no default pager port");
+
+  /* Initialize the diskfs library.  Must come before any other diskfs call. */
+  err = diskfs_init_diskfs ();
+  if (err)
+    error (4, err, "init");
+
+  err = diskfs_alloc_node (0, S_IFDIR, &diskfs_root_node);
+  if (err)
+    error (4, err, "cannot create root directory");
+
+  mutex_lock (&diskfs_root_node->lock);
+
+  diskfs_spawn_first_thread ();
+
+  /* Now that we are all set up to handle requests, and diskfs_root_node is
+     set properly, it is safe to export our fsys control port to the
+     outside world.  */
+  realnode = diskfs_startup_diskfs (bootstrap, 0);
+
+  /* Propagate permissions, owner, etc. from underlying node to
+     the root directory of the new (empty) filesystem.  */
+  err = io_stat (realnode, &st);
+  mach_port_deallocate (mach_task_self (), realnode);
+  if (err)
+    {
+      error (0, err, "cannot stat underlying node");
+      diskfs_root_node->dn_stat.st_mode = S_IFDIR | 0777 | S_ISVTX;
+      diskfs_root_node->dn_set_ctime = 1;
+      diskfs_root_node->dn_set_mtime = 1;
+      diskfs_root_node->dn_set_atime = 1;
+    }
+  else
+    {
+      diskfs_root_node->dn_stat.st_mode = S_IFDIR | (st.st_mode &~ S_IFMT);
+      diskfs_root_node->dn_stat.st_uid = st.st_uid;
+      diskfs_root_node->dn_stat.st_author = st.st_author;
+      diskfs_root_node->dn_stat.st_gid = st.st_gid;
+      diskfs_root_node->dn_stat.st_atime = st.st_atime;
+      diskfs_root_node->dn_stat.st_mtime = st.st_mtime;
+      diskfs_root_node->dn_stat.st_ctime = st.st_ctime;
+      diskfs_root_node->dn_stat.st_flags = st.st_flags;
+    }
+
+  mutex_unlock (&diskfs_root_node->lock);
+
+  /* and so we die, leaving others to do the real work.  */
+  cthread_exit (0);
+  /* NOTREACHED */
+  return 0;
+}