From 6c8d92e33876174fd60b53ddbd05c7a6e98ddf62 Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@gnu.org>
Date: Sat, 27 Feb 1999 23:39:00 +0000
Subject: 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.
---
serverboot/default_pager.c | 145 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 142 insertions(+), 3 deletions(-)
(limited to 'serverboot/default_pager.c')
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);
{
--
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