mirror of
https://github.com/freebsd/freebsd-src
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92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <geom/geom.h>
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#include <geom/geom_dbg.h>
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#include <geom/label/g_label.h>
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/*
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* Taken from
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* https://github.com/util-linux/util-linux/blob/master/include/swapheader.h
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*/
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#define SWAP_VERSION 1
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#define SWAP_UUID_LENGTH 16
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#define SWAP_LABEL_LENGTH 16
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#define SWAP_SIGNATURE "SWAPSPACE2"
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#define SWAP_SIGNATURE_SZ (sizeof(SWAP_SIGNATURE) - 1)
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struct swap_header_v1_2 {
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char bootbits[1024]; /* Space for disklabel etc. */
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uint32_t version;
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uint32_t last_page;
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uint32_t nr_badpages;
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unsigned char uuid[SWAP_UUID_LENGTH];
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char volume_name[SWAP_LABEL_LENGTH];
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uint32_t padding[117];
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uint32_t badpages[1];
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};
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typedef union {
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struct swap_header_v1_2 header;
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struct {
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uint8_t reserved[PAGE_SIZE - SWAP_SIGNATURE_SZ];
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char signature[SWAP_SIGNATURE_SZ];
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} tail;
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} swhdr_t;
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#define sw_version header.version
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#define sw_volume_name header.volume_name
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#define sw_signature tail.signature
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static void
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g_label_swaplinux_taste(struct g_consumer *cp, char *label, size_t size)
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{
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struct g_provider *pp;
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swhdr_t *hdr;
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g_topology_assert_not();
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pp = cp->provider;
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label[0] = '\0';
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KASSERT(pp->sectorsize != 0, ("Tasting a disk with 0 sectorsize"));
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if ((PAGE_SIZE % pp->sectorsize) != 0)
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return;
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hdr = (swhdr_t *)g_read_data(cp, 0, PAGE_SIZE, NULL);
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if (hdr == NULL)
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return;
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/* Check version and magic string */
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if (hdr->sw_version == SWAP_VERSION &&
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!memcmp(hdr->sw_signature, SWAP_SIGNATURE, SWAP_SIGNATURE_SZ))
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G_LABEL_DEBUG(1, "linux swap detected on %s.", pp->name);
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else
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goto exit_free;
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/* Check for volume label */
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if (hdr->sw_volume_name[0] == '\0')
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goto exit_free;
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/* Terminate label */
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hdr->sw_volume_name[sizeof(hdr->sw_volume_name) - 1] = '\0';
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strlcpy(label, hdr->sw_volume_name, size);
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exit_free:
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g_free(hdr);
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}
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struct g_label_desc g_label_swaplinux = {
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.ld_taste = g_label_swaplinux_taste,
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.ld_dirprefix = "swaplinux/",
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.ld_enabled = 1
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};
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G_LABEL_INIT(swaplinux, g_label_swaplinux, "Create device nodes for Linux swap");
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