1999-02-27 Roland McGrath <roland@baalperazim.frob.com>

	* def_pager_setup.c (add_paging_file): New arg CHECK_LINUX_SIGNATURE,
	pass down to create_paging_partition.
	* default_pager.c (create_paging_partition): New arg
	CHECK_LINUX_SIGNATURE, pass down new_partition.
	(new_partition): New arg CHECK_LINUX_SIGNATURE: if not < 0,
	check first page of swap for Linux 2.0 or 2.2 signature page and obey
	its bad-block map; if > 0, refuse the partition if no signature found.
	* bootstrap.c (main): Add new boot script functions
	`add-raw-paging-file', `add-linux-paging-file'.  Make those
	and `add-paging-file' all call add_paging_file with new
	LINUX_SIGNATURE arg of -1, 1, and 0, respectively.
	* default_pager.c (create_paging_partition): If new_partition returns
	null, return and do nothing more.

3 files changed, 172 insertions, 14 deletions

diff --git a/serverboot/bootstrap.c b/serverboot/bootstrap.c
index 3fa0f404..5c4a0393 100644
--- a/serverboot/bootstrap.c
+++ b/serverboot/bootstrap.c
@@ -146,12 +146,25 @@ main(argc, argv)
 {
   int doing_default_pager = 0;
   int had_a_partition = 0;
-  int script_paging_file (const struct cmd *cmd, int *val)
+  int script_paging_file (const struct cmd *cmd, int linux_signature)
     {
       if (add_paging_file (bootstrap_master_device_port, cmd->path))
 	printf ("(serverboot): %s: Cannot add paging file\n", cmd->path);
       else
 	had_a_partition = 1;
+      return 0;
+    }
+  int script_add_paging_file (const struct cmd *cmd, int *val)
+    {
+      return script_paging_file (cmd, 0);
+    }
+  int script_add_raw_paging_file (const struct cmd *cmd, int *val)
+    {
+      return script_paging_file (cmd, -1);
+    }
+  int script_add_linux_paging_file (const struct cmd *cmd, int *val)
+    {
+      return script_paging_file (cmd, 1);
     }
   int script_default_pager (const struct cmd *cmd, int *val)
     {
@@ -178,9 +191,9 @@ main(argc, argv)
 	 */
 	if (argv[1][0] != '-')
 	  panic("bootstrap: no flags");
-	
+
 	flag_string = argv[1];
-	    
+
 	/*
 	 * Parse the arguments.
 	 */
@@ -208,13 +221,13 @@ main(argc, argv)
 	else if (argc == 3)
 	  {
 	    root_name = argv[2];
-	    
+
 	    get_privileged_ports (&bootstrap_master_host_port,
 				  &bootstrap_master_device_port);
 	  }
-	
-	    
-	
+
+
+
 
 	printf_init(bootstrap_master_device_port);
 #ifdef pleasenoXXX
@@ -275,7 +288,7 @@ main(argc, argv)
 	    }
 	    break;
 	}
-	
+
 	/*
 	 * If the server boot script name was changed,
 	 * then use the new device name as the root device.
@@ -309,7 +322,12 @@ main(argc, argv)
 	      || boot_script_set_variable ("boot-args", VAL_STR,
 					   (int) flag_string)
 	      || boot_script_define_function ("add-paging-file", VAL_NONE,
-					      &script_paging_file)
+					      &script_add_paging_file)
+	      || boot_script_define_function ("add-raw-paging-file", VAL_NONE,
+					      &script_add_raw_paging_file)
+	      || boot_script_define_function ("add-linux-paging-file",
+					      VAL_NONE,
+					      &script_add_linux_paging_file)
 	      || boot_script_define_function ("default-pager", VAL_NONE,
 					      &script_default_pager)
 	      )
diff --git a/serverboot/def_pager_setup.c b/serverboot/def_pager_setup.c
index fe6b33ab..cd72acea 100644
--- a/serverboot/def_pager_setup.c
+++ b/serverboot/def_pager_setup.c
@@ -35,9 +35,10 @@ extern void *kalloc();
 extern void	create_paging_partition();
 
 kern_return_t
-add_paging_file(master_device_port, file_name)
+add_paging_file(master_device_port, file_name, linux_signature)
 	mach_port_t		master_device_port;
 	char			*file_name;
+	int			linux_signature;
 {
 	register struct file_direct *fdp;
 	register kern_return_t	result;
@@ -68,7 +69,7 @@ add_paging_file(master_device_port, file_name)
 	/*
 	 * Set up the default paging partition
 	 */
-	create_paging_partition(file_name, fdp, isa_file);
+	create_paging_partition(file_name, fdp, isa_file, linux_signature);
 
 	return result;
 }
diff --git a/serverboot/default_pager.c b/serverboot/default_pager.c
index 159cd576..dc1e7ff6 100644
--- a/serverboot/default_pager.c
+++ b/serverboot/default_pager.c
@@ -163,10 +163,14 @@ partition_init()
 }
 
 static partition_t
-new_partition (const char *name, struct file_direct *fdp)
+new_partition (const char *name, struct file_direct *fdp,
+	       int check_linux_signature)
 {
 	register partition_t	part;
 	register vm_size_t	size, bmsize;
+	vm_offset_t raddr;
+	mach_msg_type_number_t rsize;
+	int rc;
 
 	size = atop(fdp->fd_size * fdp->fd_bsize);
 	bmsize = howmany(size, NB_BM) * sizeof(bm_entry_t);
@@ -182,6 +186,138 @@ new_partition (const char *name, struct file_direct *fdp)
 
 	bzero((char *)part->bitmap, bmsize);
 
+	if (check_linux_signature < 0)
+	  return part;
+
+#define LINUX_PAGE_SIZE 4096	/* size of pages in Linux swap partitions */
+	rc = page_read_file_direct(part->file,
+				   0, LINUX_PAGE_SIZE,
+				   &raddr,
+				   &rsize);
+	if (rc)
+	  panic("(default pager): cannot read first page of %s! rc=%#x\n",
+		name, rc);
+	if (rsize != LINUX_PAGE_SIZE)
+	  panic("(default pager): bad read on first page of %s! size=%u\n",
+		name, rsize);
+	if (!memcmp("SWAP-SPACE", (char *) raddr + LINUX_PAGE_SIZE-10, 10))
+	  {
+	    /* The partition's first page has a Linux swap signature.
+	       This means the beginning of the page contains a bitmap
+	       of good pages, and all others are bad.  */
+	    unsigned int i, j, bad;
+	    printf("(default pager): Found Linux 2.0 swap signature in %s...",
+		   name);
+	    part->bitmap[0] |= 1; /* first page unusable */
+	    part->free--;
+	    bad = 0;
+	    memset((char *) raddr + LINUX_PAGE_SIZE-10, 0, 10);
+	    for (i = 0; i < LINUX_PAGE_SIZE / sizeof(bm_entry_t); ++i)
+	      {
+		bm_entry_t bm = ((bm_entry_t *) raddr)[i];
+		if (bm == BM_MASK)
+		  continue;
+		/* There are some zero bits in this word.  */
+		for (j = 0; j < NB_BM; ++j)
+		  if ((bm & (1 << j)) == 0)
+		    {
+		      ++bad;
+		      part->bitmap[i] |= 1 << j;
+		    }
+	      }
+	    part->free -= bad;
+	    printf ("%dk swap-space (excludes %dk marked bad)\n",
+		    part->free * (LINUX_PAGE_SIZE / 1024),
+		    bad * (LINUX_PAGE_SIZE / 1024));
+	    if (part->total_size > 8 * LINUX_PAGE_SIZE)
+	      {
+		unsigned int waste = part->total_size - (8 * LINUX_PAGE_SIZE);
+		part->free -= waste;
+		part->total_size -= waste;
+		printf("\
+(default pager): NOTE: wasting last %dk of %s past Linux max swapfile size\n",
+		       waste * (LINUX_PAGE_SIZE / 1024), name);
+	      }
+	  }
+	else if (!memcmp("SWAPSPACE2",
+			 (char *) raddr + LINUX_PAGE_SIZE-10, 10))
+	  {
+	    struct
+	    {
+	      u_int8_t bootbits[1024];
+	      u_int32_t version;
+	      u_int32_t last_page;
+	      u_int32_t nr_badpages;
+	      u_int32_t padding[125];
+	      u_int32_t badpages[1];
+	    } *hdr = (void *) raddr;
+
+	    printf("\
+(default pager): Found Linux 2.2 swap signature (v%u) in %s...",
+		   name, hdr->version);
+
+	    part->bitmap[0] |= 1; /* first page unusable */
+	    part->free--;
+
+	    switch (hdr->version)
+	      {
+	      default:
+		if (check_linux_signature)
+		  {
+		    printf ("version %u unknown!  SKIPPING %s!\n",
+			    hdr->version,
+			    name);
+		    return 0;
+		  }
+		else
+		printf ("version %u unknown! IGNORING SIGNATURE PAGE!"
+			" %dk swap-space\n",
+			hdr->version,
+			part->free * (LINUX_PAGE_SIZE / 1024));
+		break;
+
+	      case 1:
+		{
+		  unsigned int waste, i;
+		  if (hdr->last_page > part->total_size)
+		    {
+		      printf ("signature says %uk, partition has only %uk! ",
+			    hdr->last_page * (LINUX_PAGE_SIZE / 1024),
+			    part->total_size * (LINUX_PAGE_SIZE / 1024));
+		      waste = 0;
+		    }
+		  else
+		    {
+		      waste = part->total_size - hdr->last_page;
+		      part->total_size = hdr->last_page;
+		    }
+		  for (i = 0; i < hdr->nr_badpages; ++i)
+		    {
+		      const u_int32_t bad = hdr->badpages[i];
+		      part->bitmap[bad / NB_BM] |= 1 << (i % NB_BM);
+		      part->free--;
+		    }
+		  printf ("%uk swap-space",
+			  part->free * (LINUX_PAGE_SIZE / 1024));
+		  if (hdr->nr_badpages != 0)
+		    printf (" (excludes %uk marked bad)",
+			    hdr->nr_badpages * (LINUX_PAGE_SIZE / 1024));
+		  if (waste != 0)
+		    printf (" (excludes %uk pages at end of partition)",
+			    waste * (LINUX_PAGE_SIZE / 1024));
+		  printf ("\n");
+		}
+	      }
+	  }
+	else if (check_linux_signature)
+	  {
+	    part = 0;
+	    printf ("(default pager): "
+		    "Cannot find Linux swap signature page!  SKIPPING %s!",
+		    name);
+	  }
+	vm_deallocate(mach_task_self(), raddr, rsize);
+
 	return part;
 }
 
@@ -192,11 +328,14 @@ new_partition (const char *name, struct file_direct *fdp)
  */
 void
 create_paging_partition(const char *name,
-			struct file_direct *fdp, int isa_file)
+			struct file_direct *fdp, int isa_file,
+			int linux_signature)
 {
 	register partition_t	part;
 
-	part = new_partition (name, fdp);
+	part = new_partition (name, fdp, linux_signature);
+	if (!part)
+	  return;
 
 	mutex_lock(&all_partitions.lock);
 	{