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-rw-r--r--block/uuid.c509
1 files changed, 509 insertions, 0 deletions
diff --git a/block/uuid.c b/block/uuid.c
new file mode 100644
index 000000000..4610d7b8f
--- /dev/null
+++ b/block/uuid.c
@@ -0,0 +1,509 @@
+#include <linux/blkdev.h>
+#include <linux/ctype.h>
+#include <linux/fs_uuid.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+static int debug_enabled;
+
+#define PRINTK(fmt, args...) do { \
+ if (debug_enabled) \
+ printk(KERN_DEBUG fmt, ## args); \
+ } while(0)
+
+#define PRINT_HEX_DUMP(v1, v2, v3, v4, v5, v6, v7, v8) \
+ do { \
+ if (debug_enabled) \
+ print_hex_dump(v1, v2, v3, v4, v5, v6, v7, v8); \
+ } while(0)
+
+/*
+ * Simple UUID translation
+ */
+
+struct uuid_info {
+ const char *key;
+ const char *name;
+ long bkoff;
+ unsigned sboff;
+ unsigned sig_len;
+ const char *magic;
+ int uuid_offset;
+ int last_mount_offset;
+ int last_mount_size;
+};
+
+/*
+ * Based on libuuid's blkid_magic array. Note that I don't
+ * have uuid offsets for all of these yet - mssing ones are 0x0.
+ * Further information welcome.
+ *
+ * Rearranged by page of fs signature for optimisation.
+ */
+static struct uuid_info uuid_list[] = {
+ { NULL, "oracleasm", 0, 32, 8, "ORCLDISK", 0x0, 0, 0 },
+ { "ntfs", "ntfs", 0, 3, 8, "NTFS ", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0x52, 5, "MSWIN", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0x52, 8, "FAT32 ", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0x36, 5, "MSDOS", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0x36, 8, "FAT16 ", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0x36, 8, "FAT12 ", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0, 1, "\353", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0, 1, "\351", 0x0, 0, 0 },
+ { "vfat", "vfat", 0, 0x1fe, 2, "\125\252", 0x0, 0, 0 },
+ { "xfs", "xfs", 0, 0, 4, "XFSB", 0x20, 0, 0 },
+ { "romfs", "romfs", 0, 0, 8, "-rom1fs-", 0x0, 0, 0 },
+ { "bfs", "bfs", 0, 0, 4, "\316\372\173\033", 0, 0, 0 },
+ { "cramfs", "cramfs", 0, 0, 4, "E=\315\050", 0x0, 0, 0 },
+ { "qnx4", "qnx4", 0, 4, 6, "QNX4FS", 0, 0, 0 },
+ { NULL, "crypt_LUKS", 0, 0, 6, "LUKS\xba\xbe", 0x0, 0, 0 },
+ { "squashfs", "squashfs", 0, 0, 4, "sqsh", 0, 0, 0 },
+ { "squashfs", "squashfs", 0, 0, 4, "hsqs", 0, 0, 0 },
+ { "ocfs", "ocfs", 0, 8, 9, "OracleCFS", 0x0, 0, 0 },
+ { "lvm2pv", "lvm2pv", 0, 0x018, 8, "LVM2 001", 0x0, 0, 0 },
+ { "sysv", "sysv", 0, 0x3f8, 4, "\020~\030\375", 0, 0, 0 },
+ { "ext", "ext", 1, 0x38, 2, "\123\357", 0x468, 0x42c, 4 },
+ { "minix", "minix", 1, 0x10, 2, "\177\023", 0, 0, 0 },
+ { "minix", "minix", 1, 0x10, 2, "\217\023", 0, 0, 0 },
+ { "minix", "minix", 1, 0x10, 2, "\150\044", 0, 0, 0 },
+ { "minix", "minix", 1, 0x10, 2, "\170\044", 0, 0, 0 },
+ { "lvm2pv", "lvm2pv", 1, 0x018, 8, "LVM2 001", 0x0, 0, 0 },
+ { "vxfs", "vxfs", 1, 0, 4, "\365\374\001\245", 0, 0, 0 },
+ { "hfsplus", "hfsplus", 1, 0, 2, "BD", 0x0, 0, 0 },
+ { "hfsplus", "hfsplus", 1, 0, 2, "H+", 0x0, 0, 0 },
+ { "hfsplus", "hfsplus", 1, 0, 2, "HX", 0x0, 0, 0 },
+ { "hfs", "hfs", 1, 0, 2, "BD", 0x0, 0, 0 },
+ { "ocfs2", "ocfs2", 1, 0, 6, "OCFSV2", 0x0, 0, 0 },
+ { "lvm2pv", "lvm2pv", 0, 0x218, 8, "LVM2 001", 0x0, 0, 0 },
+ { "lvm2pv", "lvm2pv", 1, 0x218, 8, "LVM2 001", 0x0, 0, 0 },
+ { "ocfs2", "ocfs2", 2, 0, 6, "OCFSV2", 0x0, 0, 0 },
+ { "swap", "swap", 0, 0xff6, 10, "SWAP-SPACE", 0x40c, 0, 0 },
+ { "swap", "swap", 0, 0xff6, 10, "SWAPSPACE2", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0xff6, 9, "S1SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0xff6, 9, "S2SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0xff6, 9, "ULSUSPEND", 0x40c, 0, 0 },
+ { "ocfs2", "ocfs2", 4, 0, 6, "OCFSV2", 0x0, 0, 0 },
+ { "ocfs2", "ocfs2", 8, 0, 6, "OCFSV2", 0x0, 0, 0 },
+ { "hpfs", "hpfs", 8, 0, 4, "I\350\225\371", 0, 0, 0 },
+ { "reiserfs", "reiserfs", 8, 0x34, 8, "ReIsErFs", 0x10054, 0, 0 },
+ { "reiserfs", "reiserfs", 8, 20, 8, "ReIsErFs", 0x10054, 0, 0 },
+ { "zfs", "zfs", 8, 0, 8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", 0x0, 0, 0 },
+ { "zfs", "zfs", 8, 0, 8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", 0x0, 0, 0 },
+ { "ufs", "ufs", 8, 0x55c, 4, "T\031\001\000", 0, 0, 0 },
+ { "swap", "swap", 0, 0x1ff6, 10, "SWAP-SPACE", 0x40c, 0, 0 },
+ { "swap", "swap", 0, 0x1ff6, 10, "SWAPSPACE2", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x1ff6, 9, "S1SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x1ff6, 9, "S2SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x1ff6, 9, "ULSUSPEND", 0x40c, 0, 0 },
+ { "reiserfs", "reiserfs", 64, 0x34, 9, "ReIsEr2Fs", 0x10054, 0, 0 },
+ { "reiserfs", "reiserfs", 64, 0x34, 9, "ReIsEr3Fs", 0x10054, 0, 0 },
+ { "reiserfs", "reiserfs", 64, 0x34, 8, "ReIsErFs", 0x10054, 0, 0 },
+ { "reiser4", "reiser4", 64, 0, 7, "ReIsEr4", 0x100544, 0, 0 },
+ { "gfs2", "gfs2", 64, 0, 4, "\x01\x16\x19\x70", 0x0, 0, 0 },
+ { "gfs", "gfs", 64, 0, 4, "\x01\x16\x19\x70", 0x0, 0, 0 },
+ { "btrfs", "btrfs", 64, 0x40, 8, "_BHRfS_M", 0x0, 0, 0 },
+ { "swap", "swap", 0, 0x3ff6, 10, "SWAP-SPACE", 0x40c, 0, 0 },
+ { "swap", "swap", 0, 0x3ff6, 10, "SWAPSPACE2", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x3ff6, 9, "S1SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x3ff6, 9, "S2SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x3ff6, 9, "ULSUSPEND", 0x40c, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "BEA01", 0x0, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "BOOT2", 0x0, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "CD001", 0x0, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "CDW02", 0x0, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "NSR02", 0x0, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "NSR03", 0x0, 0, 0 },
+ { "udf", "udf", 32, 1, 5, "TEA01", 0x0, 0, 0 },
+ { "iso9660", "iso9660", 32, 1, 5, "CD001", 0x0, 0, 0 },
+ { "iso9660", "iso9660", 32, 9, 5, "CDROM", 0x0, 0, 0 },
+ { "jfs", "jfs", 32, 0, 4, "JFS1", 0x88, 0, 0 },
+ { "swap", "swap", 0, 0x7ff6, 10, "SWAP-SPACE", 0x40c, 0, 0 },
+ { "swap", "swap", 0, 0x7ff6, 10, "SWAPSPACE2", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x7ff6, 9, "S1SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x7ff6, 9, "S2SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0x7ff6, 9, "ULSUSPEND", 0x40c, 0, 0 },
+ { "swap", "swap", 0, 0xfff6, 10, "SWAP-SPACE", 0x40c, 0, 0 },
+ { "swap", "swap", 0, 0xfff6, 10, "SWAPSPACE2", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0xfff6, 9, "S1SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0xfff6, 9, "S2SUSPEND", 0x40c, 0, 0 },
+ { "swap", "swsuspend", 0, 0xfff6, 9, "ULSUSPEND", 0x40c, 0, 0 },
+ { "zfs", "zfs", 264, 0, 8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", 0x0, 0, 0 },
+ { "zfs", "zfs", 264, 0, 8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", 0x0, 0, 0 },
+ { NULL, NULL, 0, 0, 0, NULL, 0x0, 0, 0 }
+};
+
+static int null_uuid(const char *uuid)
+{
+ int i;
+
+ for (i = 0; i < 16 && !uuid[i]; i++);
+
+ return (i == 16);
+}
+
+
+static void uuid_end_bio(struct bio *bio)
+{
+ struct page *page = bio->bi_io_vec[0].bv_page;
+
+ if (bio->bi_error)
+ SetPageError(page);
+
+ unlock_page(page);
+ bio_put(bio);
+}
+
+
+/**
+ * submit - submit BIO request
+ * @dev: The block device we're using.
+ * @page_num: The page we're reading.
+ *
+ * Based on Patrick Mochell's pmdisk code from long ago: "Straight from the
+ * textbook - allocate and initialize the bio. If we're writing, make sure
+ * the page is marked as dirty. Then submit it and carry on."
+ **/
+static struct page *read_bdev_page(struct block_device *dev, int page_num)
+{
+ struct bio *bio = NULL;
+ struct page *page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+
+ if (!page) {
+ printk(KERN_ERR "Failed to allocate a page for reading data "
+ "in UUID checks.");
+ return NULL;
+ }
+
+ bio = bio_alloc(GFP_NOFS, 1);
+ bio->bi_bdev = dev;
+ bio->bi_iter.bi_sector = page_num << 3;
+ bio->bi_end_io = uuid_end_bio;
+ bio->bi_flags |= (1 << BIO_TOI);
+
+ PRINTK("Submitting bio on device %lx, page %d using bio %p and page %p.\n",
+ (unsigned long) dev->bd_dev, page_num, bio, page);
+
+ if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+ printk(KERN_DEBUG "ERROR: adding page to bio at %d\n",
+ page_num);
+ bio_put(bio);
+ __free_page(page);
+ printk(KERN_DEBUG "read_bdev_page freed page %p (in error "
+ "path).\n", page);
+ return NULL;
+ }
+
+ lock_page(page);
+ submit_bio(READ | REQ_SYNC, bio);
+
+ wait_on_page_locked(page);
+ if (PageError(page)) {
+ __free_page(page);
+ page = NULL;
+ }
+ return page;
+}
+
+int bdev_matches_key(struct block_device *bdev, const char *key)
+{
+ unsigned char *data = NULL;
+ struct page *data_page = NULL;
+
+ int dev_offset, pg_num, pg_off, i;
+ int last_pg_num = -1;
+ int result = 0;
+ char buf[50];
+
+ if (null_uuid(key)) {
+ PRINTK("Refusing to find a NULL key.\n");
+ return 0;
+ }
+
+ if (!bdev->bd_disk) {
+ bdevname(bdev, buf);
+ PRINTK("bdev %s has no bd_disk.\n", buf);
+ return 0;
+ }
+
+ if (!bdev->bd_disk->queue) {
+ bdevname(bdev, buf);
+ PRINTK("bdev %s has no queue.\n", buf);
+ return 0;
+ }
+
+ for (i = 0; uuid_list[i].name; i++) {
+ struct uuid_info *dat = &uuid_list[i];
+
+ if (!dat->key || strcmp(dat->key, key))
+ continue;
+
+ dev_offset = (dat->bkoff << 10) + dat->sboff;
+ pg_num = dev_offset >> 12;
+ pg_off = dev_offset & 0xfff;
+
+ if ((((pg_num + 1) << 3) - 1) > bdev->bd_part->nr_sects >> 1)
+ continue;
+
+ if (pg_num != last_pg_num) {
+ if (data_page) {
+ kunmap(data_page);
+ __free_page(data_page);
+ }
+ data_page = read_bdev_page(bdev, pg_num);
+ if (!data_page)
+ continue;
+ data = kmap(data_page);
+ }
+
+ last_pg_num = pg_num;
+
+ if (strncmp(&data[pg_off], dat->magic, dat->sig_len))
+ continue;
+
+ result = 1;
+ break;
+ }
+
+ if (data_page) {
+ kunmap(data_page);
+ __free_page(data_page);
+ }
+
+ return result;
+}
+
+/*
+ * part_matches_fs_info - Does the given partition match the details given?
+ *
+ * Returns a score saying how good the match is.
+ * 0 = no UUID match.
+ * 1 = UUID but last mount time differs.
+ * 2 = UUID, last mount time but not dev_t
+ * 3 = perfect match
+ *
+ * This lets us cope elegantly with probing resulting in dev_ts changing
+ * from boot to boot, and with the case where a user copies a partition
+ * (UUID is non unique), and we need to check the last mount time of the
+ * correct partition.
+ */
+int part_matches_fs_info(struct hd_struct *part, struct fs_info *seek)
+{
+ struct block_device *bdev;
+ struct fs_info *got;
+ int result = 0;
+ char buf[50];
+
+ if (null_uuid((char *) &seek->uuid)) {
+ PRINTK("Refusing to find a NULL uuid.\n");
+ return 0;
+ }
+
+ bdev = bdget(part_devt(part));
+
+ PRINTK("part_matches fs info considering %x.\n", part_devt(part));
+
+ if (blkdev_get(bdev, FMODE_READ, 0)) {
+ PRINTK("blkdev_get failed.\n");
+ return 0;
+ }
+
+ if (!bdev->bd_disk) {
+ bdevname(bdev, buf);
+ PRINTK("bdev %s has no bd_disk.\n", buf);
+ goto out;
+ }
+
+ if (!bdev->bd_disk->queue) {
+ bdevname(bdev, buf);
+ PRINTK("bdev %s has no queue.\n", buf);
+ goto out;
+ }
+
+ got = fs_info_from_block_dev(bdev);
+
+ if (got && !memcmp(got->uuid, seek->uuid, 16)) {
+ PRINTK(" Have matching UUID.\n");
+ PRINTK(" Got: LMS %d, LM %p.\n", got->last_mount_size, got->last_mount);
+ PRINTK(" Seek: LMS %d, LM %p.\n", seek->last_mount_size, seek->last_mount);
+ result = 1;
+
+ if (got->last_mount_size == seek->last_mount_size &&
+ got->last_mount && seek->last_mount &&
+ !memcmp(got->last_mount, seek->last_mount,
+ got->last_mount_size)) {
+ result = 2;
+
+ PRINTK(" Matching last mount time.\n");
+
+ if (part_devt(part) == seek->dev_t) {
+ result = 3;
+ PRINTK(" Matching dev_t.\n");
+ } else
+ PRINTK("Dev_ts differ (%x vs %x).\n", part_devt(part), seek->dev_t);
+ }
+ }
+
+ PRINTK(" Score for %x is %d.\n", part_devt(part), result);
+ free_fs_info(got);
+out:
+ blkdev_put(bdev, FMODE_READ);
+ return result;
+}
+
+void free_fs_info(struct fs_info *fs_info)
+{
+ if (!fs_info || IS_ERR(fs_info))
+ return;
+
+ if (fs_info->last_mount)
+ kfree(fs_info->last_mount);
+
+ kfree(fs_info);
+}
+
+struct fs_info *fs_info_from_block_dev(struct block_device *bdev)
+{
+ unsigned char *data = NULL;
+ struct page *data_page = NULL;
+
+ int dev_offset, pg_num, pg_off;
+ int uuid_pg_num, uuid_pg_off, i;
+ unsigned char *uuid_data = NULL;
+ struct page *uuid_data_page = NULL;
+
+ int last_pg_num = -1, last_uuid_pg_num = 0;
+ char buf[50];
+ struct fs_info *fs_info = NULL;
+
+ bdevname(bdev, buf);
+
+ PRINTK("uuid_from_block_dev looking for partition type of %s.\n", buf);
+
+ for (i = 0; uuid_list[i].name; i++) {
+ struct uuid_info *dat = &uuid_list[i];
+ dev_offset = (dat->bkoff << 10) + dat->sboff;
+ pg_num = dev_offset >> 12;
+ pg_off = dev_offset & 0xfff;
+ uuid_pg_num = dat->uuid_offset >> 12;
+ uuid_pg_off = dat->uuid_offset & 0xfff;
+
+ if ((((pg_num + 1) << 3) - 1) > bdev->bd_part->nr_sects >> 1)
+ continue;
+
+ /* Ignore partition types with no UUID offset */
+ if (!dat->uuid_offset)
+ continue;
+
+ if (pg_num != last_pg_num) {
+ if (data_page) {
+ kunmap(data_page);
+ __free_page(data_page);
+ }
+ data_page = read_bdev_page(bdev, pg_num);
+ if (!data_page)
+ continue;
+ data = kmap(data_page);
+ }
+
+ last_pg_num = pg_num;
+
+ if (strncmp(&data[pg_off], dat->magic, dat->sig_len))
+ continue;
+
+ PRINTK("This partition looks like %s.\n", dat->name);
+
+ fs_info = kzalloc(sizeof(struct fs_info), GFP_KERNEL);
+
+ if (!fs_info) {
+ PRINTK("Failed to allocate fs_info struct.");
+ fs_info = ERR_PTR(-ENOMEM);
+ break;
+ }
+
+ /* UUID can't be off the end of the disk */
+ if ((uuid_pg_num > bdev->bd_part->nr_sects >> 3) ||
+ !dat->uuid_offset)
+ goto no_uuid;
+
+ if (!uuid_data || uuid_pg_num != last_uuid_pg_num) {
+ /* No need to reread the page from above */
+ if (uuid_pg_num == pg_num && uuid_data)
+ memcpy(uuid_data, data, PAGE_SIZE);
+ else {
+ if (uuid_data_page) {
+ kunmap(uuid_data_page);
+ __free_page(uuid_data_page);
+ }
+ uuid_data_page = read_bdev_page(bdev, uuid_pg_num);
+ if (!uuid_data_page)
+ continue;
+ uuid_data = kmap(uuid_data_page);
+ }
+ }
+
+ last_uuid_pg_num = uuid_pg_num;
+ memcpy(&fs_info->uuid, &uuid_data[uuid_pg_off], 16);
+ fs_info->dev_t = bdev->bd_dev;
+
+no_uuid:
+ PRINT_HEX_DUMP(KERN_EMERG, "fs_info_from_block_dev "
+ "returning uuid ", DUMP_PREFIX_NONE, 16, 1,
+ fs_info->uuid, 16, 0);
+
+ if (dat->last_mount_size) {
+ int pg = dat->last_mount_offset >> 12, sz;
+ int off = dat->last_mount_offset & 0xfff;
+ struct page *last_mount = read_bdev_page(bdev, pg);
+ unsigned char *last_mount_data;
+ char *ptr;
+
+ if (!last_mount) {
+ fs_info = ERR_PTR(-ENOMEM);
+ break;
+ }
+ last_mount_data = kmap(last_mount);
+ sz = dat->last_mount_size;
+ ptr = kmalloc(sz, GFP_KERNEL);
+
+ if (!ptr) {
+ printk(KERN_EMERG "fs_info_from_block_dev "
+ "failed to get memory for last mount "
+ "timestamp.");
+ free_fs_info(fs_info);
+ fs_info = ERR_PTR(-ENOMEM);
+ } else {
+ fs_info->last_mount = ptr;
+ fs_info->last_mount_size = sz;
+ memcpy(ptr, &last_mount_data[off], sz);
+ }
+
+ kunmap(last_mount);
+ __free_page(last_mount);
+ }
+ break;
+ }
+
+ if (data_page) {
+ kunmap(data_page);
+ __free_page(data_page);
+ }
+
+ if (uuid_data_page) {
+ kunmap(uuid_data_page);
+ __free_page(uuid_data_page);
+ }
+
+ return fs_info;
+}
+
+static int __init uuid_debug_setup(char *str)
+{
+ int value;
+
+ if (sscanf(str, "=%d", &value))
+ debug_enabled = value;
+
+ return 1;
+}
+
+__setup("uuid_debug", uuid_debug_setup);
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-11 12:12:03 +0000