OSCL-LXR linux-6.0.1/​block/​partitions/​ldm.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
  *
  * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
  * Copyright (c) 2001-2012 Anton Altaparmakov
  * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  *
  * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads 
  */
 
 #include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/stringify.h>
 #include <linux/kernel.h>
 #include <linux/uuid.h>
 #include <linux/msdos_partition.h>
 
 #include "ldm.h"
 #include "check.h"
 
 /*
  * ldm_debug/info/error/crit - Output an error message
  * @f:    A printf format string containing the message
  * @...:  Variables to substitute into @f
  *
  * ldm_debug() writes a DEBUG level message to the syslog but only if the
  * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
  */
 #ifndef CONFIG_LDM_DEBUG
 #define ldm_debug(...)  do {} while (0)
 #else
 #define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
 #endif
 
 #define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __func__, f, ##a)
 #define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __func__, f, ##a)
 #define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __func__, f, ##a)
 
 static __printf(3, 4)
 void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
 {
     struct va_format vaf;
     va_list args;
 
     va_start (args, fmt);
 
     vaf.fmt = fmt;
     vaf.va = &args;
 
     printk("%s%s(): %pV\n", level, function, &vaf);
 
     va_end(args);
 }
 
 /**
  * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
  * @data:  Raw database PRIVHEAD structure loaded from the device
  * @ph:    In-memory privhead structure in which to return parsed information
  *
  * This parses the LDM database PRIVHEAD structure supplied in @data and
  * sets up the in-memory privhead structure @ph with the obtained information.
  *
  * Return:  'true'   @ph contains the PRIVHEAD data
  *          'false'  @ph contents are undefined
  */
 static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
 {
     bool is_vista = false;
 
     BUG_ON(!data || !ph);
     if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
         ldm_error("Cannot find PRIVHEAD structure. LDM database is"
             " corrupt. Aborting.");
         return false;
     }
     ph->ver_major = get_unaligned_be16(data + 0x000C);
     ph->ver_minor = get_unaligned_be16(data + 0x000E);
     ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
     ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
     ph->config_start = get_unaligned_be64(data + 0x012B);
     ph->config_size = get_unaligned_be64(data + 0x0133);
     /* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
     if (ph->ver_major == 2 && ph->ver_minor == 12)
         is_vista = true;
     if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
         ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
             " Aborting.", ph->ver_major, ph->ver_minor);
         return false;
     }
     ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
             ph->ver_minor, is_vista ? "Vista" : "2000/XP");
     if (ph->config_size != LDM_DB_SIZE) {   /* 1 MiB in sectors. */
         /* Warn the user and continue, carefully. */
         ldm_info("Database is normally %u bytes, it claims to "
             "be %llu bytes.", LDM_DB_SIZE,
             (unsigned long long)ph->config_size);
     }
     if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
             ph->logical_disk_size > ph->config_start)) {
         ldm_error("PRIVHEAD disk size doesn't match real disk size");
         return false;
     }
     if (uuid_parse(data + 0x0030, &ph->disk_id)) {
         ldm_error("PRIVHEAD contains an invalid GUID.");
         return false;
     }
     ldm_debug("Parsed PRIVHEAD successfully.");
     return true;
 }
 
 /**
  * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
  * @data:  Raw database TOCBLOCK structure loaded from the device
  * @toc:   In-memory toc structure in which to return parsed information
  *
  * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
  * in @data and sets up the in-memory tocblock structure @toc with the obtained
  * information.
  *
  * N.B.  The *_start and *_size values returned in @toc are not range-checked.
  *
  * Return:  'true'   @toc contains the TOCBLOCK data
  *          'false'  @toc contents are undefined
  */
 static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
 {
     BUG_ON (!data || !toc);
 
     if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
         ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
         return false;
     }
     strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
     toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
     toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
     toc->bitmap1_size  = get_unaligned_be64(data + 0x36);
 
     if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
             sizeof (toc->bitmap1_name)) != 0) {
         ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
                 TOC_BITMAP1, toc->bitmap1_name);
         return false;
     }
     strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
     toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
     toc->bitmap2_start = get_unaligned_be64(data + 0x50);
     toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
     if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
             sizeof (toc->bitmap2_name)) != 0) {
         ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
                 TOC_BITMAP2, toc->bitmap2_name);
         return false;
     }
     ldm_debug ("Parsed TOCBLOCK successfully.");
     return true;
 }
 
 /**
  * ldm_parse_vmdb - Read the LDM Database VMDB structure
  * @data:  Raw database VMDB structure loaded from the device
  * @vm:    In-memory vmdb structure in which to return parsed information
  *
  * This parses the LDM Database VMDB structure supplied in @data and sets up
  * the in-memory vmdb structure @vm with the obtained information.
  *
  * N.B.  The *_start, *_size and *_seq values will be range-checked later.
  *
  * Return:  'true'   @vm contains VMDB info
  *          'false'  @vm contents are undefined
  */
 static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
 {
     BUG_ON (!data || !vm);
 
     if (MAGIC_VMDB != get_unaligned_be32(data)) {
         ldm_crit ("Cannot find the VMDB, database may be corrupt.");
         return false;
     }
 
     vm->ver_major = get_unaligned_be16(data + 0x12);
     vm->ver_minor = get_unaligned_be16(data + 0x14);
     if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
         ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
             "Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
         return false;
     }
 
     vm->vblk_size     = get_unaligned_be32(data + 0x08);
     if (vm->vblk_size == 0) {
         ldm_error ("Illegal VBLK size");
         return false;
     }
 
     vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
     vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
 
     ldm_debug ("Parsed VMDB successfully.");
     return true;
 }
 
 /**
  * ldm_compare_privheads - Compare two privhead objects
  * @ph1:  First privhead
  * @ph2:  Second privhead
  *
  * This compares the two privhead structures @ph1 and @ph2.
  *
  * Return:  'true'   Identical
  *          'false'  Different
  */
 static bool ldm_compare_privheads (const struct privhead *ph1,
                    const struct privhead *ph2)
 {
     BUG_ON (!ph1 || !ph2);
 
     return ((ph1->ver_major          == ph2->ver_major)     &&
         (ph1->ver_minor          == ph2->ver_minor)     &&
         (ph1->logical_disk_start == ph2->logical_disk_start)    &&
         (ph1->logical_disk_size  == ph2->logical_disk_size) &&
         (ph1->config_start       == ph2->config_start)      &&
         (ph1->config_size        == ph2->config_size)       &&
         uuid_equal(&ph1->disk_id, &ph2->disk_id));
 }
 
 /**
  * ldm_compare_tocblocks - Compare two tocblock objects
  * @toc1:  First toc
  * @toc2:  Second toc
  *
  * This compares the two tocblock structures @toc1 and @toc2.
  *
  * Return:  'true'   Identical
  *          'false'  Different
  */
 static bool ldm_compare_tocblocks (const struct tocblock *toc1,
                    const struct tocblock *toc2)
 {
     BUG_ON (!toc1 || !toc2);
 
     return ((toc1->bitmap1_start == toc2->bitmap1_start)    &&
         (toc1->bitmap1_size  == toc2->bitmap1_size) &&
         (toc1->bitmap2_start == toc2->bitmap2_start)    &&
         (toc1->bitmap2_size  == toc2->bitmap2_size) &&
         !strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
             sizeof (toc1->bitmap1_name))        &&
         !strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
             sizeof (toc1->bitmap2_name)));
 }
 
 /**
  * ldm_validate_privheads - Compare the primary privhead with its backups
  * @state: Partition check state including device holding the LDM Database
  * @ph1:   Memory struct to fill with ph contents
  *
  * Read and compare all three privheads from disk.
  *
  * The privheads on disk show the size and location of the main disk area and
  * the configuration area (the database).  The values are range-checked against
  * @hd, which contains the real size of the disk.
  *
  * Return:  'true'   Success
  *          'false'  Error
  */
 static bool ldm_validate_privheads(struct parsed_partitions *state,
                    struct privhead *ph1)
 {
     static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
     struct privhead *ph[3] = { ph1 };
     Sector sect;
     u8 *data;
     bool result = false;
     long num_sects;
     int i;
 
     BUG_ON (!state || !ph1);
 
     ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
     ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
     if (!ph[1] || !ph[2]) {
         ldm_crit ("Out of memory.");
         goto out;
     }
 
     /* off[1 & 2] are relative to ph[0]->config_start */
     ph[0]->config_start = 0;
 
     /* Read and parse privheads */
     for (i = 0; i < 3; i++) {
         data = read_part_sector(state, ph[0]->config_start + off[i],
                     &sect);
         if (!data) {
             ldm_crit ("Disk read failed.");
             goto out;
         }
         result = ldm_parse_privhead (data, ph[i]);
         put_dev_sector (sect);
         if (!result) {
             ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
             if (i < 2)
                 goto out;   /* Already logged */
             else
                 break;  /* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
         }
     }
 
     num_sects = get_capacity(state->disk);
 
     if ((ph[0]->config_start > num_sects) ||
        ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
         ldm_crit ("Database extends beyond the end of the disk.");
         goto out;
     }
 
     if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
        ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
             > ph[0]->config_start)) {
         ldm_crit ("Disk and database overlap.");
         goto out;
     }
 
     if (!ldm_compare_privheads (ph[0], ph[1])) {
         ldm_crit ("Primary and backup PRIVHEADs don't match.");
         goto out;
     }
     /* FIXME ignore this for now
     if (!ldm_compare_privheads (ph[0], ph[2])) {
         ldm_crit ("Primary and backup PRIVHEADs don't match.");
         goto out;
     }*/
     ldm_debug ("Validated PRIVHEADs successfully.");
     result = true;
 out:
     kfree (ph[1]);
     kfree (ph[2]);
     return result;
 }
 
 /**
  * ldm_validate_tocblocks - Validate the table of contents and its backups
  * @state: Partition check state including device holding the LDM Database
  * @base:  Offset, into @state->disk, of the database
  * @ldb:   Cache of the database structures
  *
  * Find and compare the four tables of contents of the LDM Database stored on
  * @state->disk and return the parsed information into @toc1.
  *
  * The offsets and sizes of the configs are range-checked against a privhead.
  *
  * Return:  'true'   @toc1 contains validated TOCBLOCK info
  *          'false'  @toc1 contents are undefined
  */
 static bool ldm_validate_tocblocks(struct parsed_partitions *state,
                    unsigned long base, struct ldmdb *ldb)
 {
     static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
     struct tocblock *tb[4];
     struct privhead *ph;
     Sector sect;
     u8 *data;
     int i, nr_tbs;
     bool result = false;
 
     BUG_ON(!state || !ldb);
     ph = &ldb->ph;
     tb[0] = &ldb->toc;
     tb[1] = kmalloc_array(3, sizeof(*tb[1]), GFP_KERNEL);
     if (!tb[1]) {
         ldm_crit("Out of memory.");
         goto err;
     }
     tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
     tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
     /*
      * Try to read and parse all four TOCBLOCKs.
      *
      * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
      * skip any that fail as long as we get at least one valid TOCBLOCK.
      */
     for (nr_tbs = i = 0; i < 4; i++) {
         data = read_part_sector(state, base + off[i], &sect);
         if (!data) {
             ldm_error("Disk read failed for TOCBLOCK %d.", i);
             continue;
         }
         if (ldm_parse_tocblock(data, tb[nr_tbs]))
             nr_tbs++;
         put_dev_sector(sect);
     }
     if (!nr_tbs) {
         ldm_crit("Failed to find a valid TOCBLOCK.");
         goto err;
     }
     /* Range check the TOCBLOCK against a privhead. */
     if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
             ((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
             ph->config_size)) {
         ldm_crit("The bitmaps are out of range.  Giving up.");
         goto err;
     }
     /* Compare all loaded TOCBLOCKs. */
     for (i = 1; i < nr_tbs; i++) {
         if (!ldm_compare_tocblocks(tb[0], tb[i])) {
             ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
             goto err;
         }
     }
     ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
     result = true;
 err:
     kfree(tb[1]);
     return result;
 }
 
 /**
  * ldm_validate_vmdb - Read the VMDB and validate it
  * @state: Partition check state including device holding the LDM Database
  * @base:  Offset, into @bdev, of the database
  * @ldb:   Cache of the database structures
  *
  * Find the vmdb of the LDM Database stored on @bdev and return the parsed
  * information in @ldb.
  *
  * Return:  'true'   @ldb contains validated VBDB info
  *          'false'  @ldb contents are undefined
  */
 static bool ldm_validate_vmdb(struct parsed_partitions *state,
                   unsigned long base, struct ldmdb *ldb)
 {
     Sector sect;
     u8 *data;
     bool result = false;
     struct vmdb *vm;
     struct tocblock *toc;
 
     BUG_ON (!state || !ldb);
 
     vm  = &ldb->vm;
     toc = &ldb->toc;
 
     data = read_part_sector(state, base + OFF_VMDB, &sect);
     if (!data) {
         ldm_crit ("Disk read failed.");
         return false;
     }
 
     if (!ldm_parse_vmdb (data, vm))
         goto out;               /* Already logged */
 
     /* Are there uncommitted transactions? */
     if (get_unaligned_be16(data + 0x10) != 0x01) {
         ldm_crit ("Database is not in a consistent state.  Aborting.");
         goto out;
     }
 
     if (vm->vblk_offset != 512)
         ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
 
     /*
      * The last_vblkd_seq can be before the end of the vmdb, just make sure
      * it is not out of bounds.
      */
     if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
         ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
                 "Database is corrupt.  Aborting.");
         goto out;
     }
 
     result = true;
 out:
     put_dev_sector (sect);
     return result;
 }
 
 
 /**
  * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
  * @state: Partition check state including device holding the LDM Database
  *
  * This function provides a weak test to decide whether the device is a dynamic
  * disk or not.  It looks for an MS-DOS-style partition table containing at
  * least one partition of type 0x42 (formerly SFS, now used by Windows for
  * dynamic disks).
  *
  * N.B.  The only possible error can come from the read_part_sector and that is
  *       only likely to happen if the underlying device is strange.  If that IS
  *       the case we should return zero to let someone else try.
  *
  * Return:  'true'   @state->disk is a dynamic disk
  *          'false'  @state->disk is not a dynamic disk, or an error occurred
  */
 static bool ldm_validate_partition_table(struct parsed_partitions *state)
 {
     Sector sect;
     u8 *data;
     struct msdos_partition *p;
     int i;
     bool result = false;
 
     BUG_ON(!state);
 
     data = read_part_sector(state, 0, &sect);
     if (!data) {
         ldm_info ("Disk read failed.");
         return false;
     }
 
     if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
         goto out;
 
     p = (struct msdos_partition *)(data + 0x01BE);
     for (i = 0; i < 4; i++, p++)
         if (p->sys_ind == LDM_PARTITION) {
             result = true;
             break;
         }
 
     if (result)
         ldm_debug ("Found W2K dynamic disk partition type.");
 
 out:
     put_dev_sector (sect);
     return result;
 }
 
 /**
  * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
  * @ldb:  Cache of the database structures
  *
  * The LDM Database contains a list of all partitions on all dynamic disks.
  * The primary PRIVHEAD, at the beginning of the physical disk, tells us
  * the GUID of this disk.  This function searches for the GUID in a linked
  * list of vblk's.
  *
  * Return:  Pointer, A matching vblk was found
  *          NULL,    No match, or an error
  */
 static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
 {
     struct list_head *item;
 
     BUG_ON (!ldb);
 
     list_for_each (item, &ldb->v_disk) {
         struct vblk *v = list_entry (item, struct vblk, list);
         if (uuid_equal(&v->vblk.disk.disk_id, &ldb->ph.disk_id))
             return v;
     }
 
     return NULL;
 }
 
 /**
  * ldm_create_data_partitions - Create data partitions for this device
  * @pp:   List of the partitions parsed so far
  * @ldb:  Cache of the database structures
  *
  * The database contains ALL the partitions for ALL disk groups, so we need to
  * filter out this specific disk. Using the disk's object id, we can find all
  * the partitions in the database that belong to this disk.
  *
  * Add each partition in our database, to the parsed_partitions structure.
  *
  * N.B.  This function creates the partitions in the order it finds partition
  *       objects in the linked list.
  *
  * Return:  'true'   Partition created
  *          'false'  Error, probably a range checking problem
  */
 static bool ldm_create_data_partitions (struct parsed_partitions *pp,
                     const struct ldmdb *ldb)
 {
     struct list_head *item;
     struct vblk *vb;
     struct vblk *disk;
     struct vblk_part *part;
     int part_num = 1;
 
     BUG_ON (!pp || !ldb);
 
     disk = ldm_get_disk_objid (ldb);
     if (!disk) {
         ldm_crit ("Can't find the ID of this disk in the database.");
         return false;
     }
 
     strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
 
     /* Create the data partitions */
     list_for_each (item, &ldb->v_part) {
         vb = list_entry (item, struct vblk, list);
         part = &vb->vblk.part;
 
         if (part->disk_id != disk->obj_id)
             continue;
 
         put_partition (pp, part_num, ldb->ph.logical_disk_start +
                 part->start, part->size);
         part_num++;
     }
 
     strlcat(pp->pp_buf, "\n", PAGE_SIZE);
     return true;
 }
 
 
 /**
  * ldm_relative - Calculate the next relative offset
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @base:    Size of the previous fixed width fields
  * @offset:  Cumulative size of the previous variable-width fields
  *
  * Because many of the VBLK fields are variable-width, it's necessary
  * to calculate each offset based on the previous one and the length
  * of the field it pointed to.
  *
  * Return:  -1 Error, the calculated offset exceeded the size of the buffer
  *           n OK, a range-checked offset into buffer
  */
 static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
 {
 
     base += offset;
     if (!buffer || offset < 0 || base > buflen) {
         if (!buffer)
             ldm_error("!buffer");
         if (offset < 0)
             ldm_error("offset (%d) < 0", offset);
         if (base > buflen)
             ldm_error("base (%d) > buflen (%d)", base, buflen);
         return -1;
     }
     if (base + buffer[base] >= buflen) {
         ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
                 buffer[base], buflen);
         return -1;
     }
     return buffer[base] + offset + 1;
 }
 
 /**
  * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
  * @block:  Pointer to the variable-width number to convert
  *
  * Large numbers in the LDM Database are often stored in a packed format.  Each
  * number is prefixed by a one byte width marker.  All numbers in the database
  * are stored in big-endian byte order.  This function reads one of these
  * numbers and returns the result
  *
  * N.B.  This function DOES NOT perform any range checking, though the most
  *       it will read is eight bytes.
  *
  * Return:  n A number
  *          0 Zero, or an error occurred
  */
 static u64 ldm_get_vnum (const u8 *block)
 {
     u64 tmp = 0;
     u8 length;
 
     BUG_ON (!block);
 
     length = *block++;
 
     if (length && length <= 8)
         while (length--)
             tmp = (tmp << 8) | *block++;
     else
         ldm_error ("Illegal length %d.", length);
 
     return tmp;
 }
 
 /**
  * ldm_get_vstr - Read a length-prefixed string into a buffer
  * @block:   Pointer to the length marker
  * @buffer:  Location to copy string to
  * @buflen:  Size of the output buffer
  *
  * Many of the strings in the LDM Database are not NULL terminated.  Instead
  * they are prefixed by a one byte length marker.  This function copies one of
  * these strings into a buffer.
  *
  * N.B.  This function DOES NOT perform any range checking on the input.
  *       If the buffer is too small, the output will be truncated.
  *
  * Return:  0, Error and @buffer contents are undefined
  *          n, String length in characters (excluding NULL)
  *          buflen-1, String was truncated.
  */
 static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
 {
     int length;
 
     BUG_ON (!block || !buffer);
 
     length = block[0];
     if (length >= buflen) {
         ldm_error ("Truncating string %d -> %d.", length, buflen);
         length = buflen - 1;
     }
     memcpy (buffer, block + 1, length);
     buffer[length] = 0;
     return length;
 }
 
 
 /**
  * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Component object (version 3) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Component VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
 {
     int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
     struct vblk_comp *comp;
 
     BUG_ON (!buffer || !vb);
 
     r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
     r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
     r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
     r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
     r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
 
     if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
         r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
         r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
         len = r_cols;
     } else {
         r_stripe = 0;
         len = r_parent;
     }
     if (len < 0)
         return false;
 
     len += VBLK_SIZE_CMP3;
     if (len != get_unaligned_be32(buffer + 0x14))
         return false;
 
     comp = &vb->vblk.comp;
     ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
         sizeof (comp->state));
     comp->type      = buffer[0x18 + r_vstate];
     comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
     comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
     comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
 
     return true;
 }
 
 /**
  * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Disk Group VBLK
  *          'false'  @vb contents are not defined
  */
 static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
 {
     int r_objid, r_name, r_diskid, r_id1, r_id2, len;
     struct vblk_dgrp *dgrp;
 
     BUG_ON (!buffer || !vb);
 
     r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
     r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
     r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
 
     if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
         r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
         r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
         len = r_id2;
     } else
         len = r_diskid;
     if (len < 0)
         return false;
 
     len += VBLK_SIZE_DGR3;
     if (len != get_unaligned_be32(buffer + 0x14))
         return false;
 
     dgrp = &vb->vblk.dgrp;
     ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
         sizeof (dgrp->disk_id));
     return true;
 }
 
 /**
  * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Disk Group VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
 {
     char buf[64];
     int r_objid, r_name, r_id1, r_id2, len;
 
     BUG_ON (!buffer || !vb);
 
     r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
     r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 
     if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
         r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
         r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
         len = r_id2;
     } else
         len = r_name;
     if (len < 0)
         return false;
 
     len += VBLK_SIZE_DGR4;
     if (len != get_unaligned_be32(buffer + 0x14))
         return false;
 
     ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
     return true;
 }
 
 /**
  * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Disk object (version 3) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Disk VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
 {
     int r_objid, r_name, r_diskid, r_altname, len;
     struct vblk_disk *disk;
 
     BUG_ON (!buffer || !vb);
 
     r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
     r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
     r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
     r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
     len = r_altname;
     if (len < 0)
         return false;
 
     len += VBLK_SIZE_DSK3;
     if (len != get_unaligned_be32(buffer + 0x14))
         return false;
 
     disk = &vb->vblk.disk;
     ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
         sizeof (disk->alt_name));
     if (uuid_parse(buffer + 0x19 + r_name, &disk->disk_id))
         return false;
 
     return true;
 }
 
 /**
  * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Disk object (version 4) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Disk VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
 {
     int r_objid, r_name, len;
     struct vblk_disk *disk;
 
     BUG_ON (!buffer || !vb);
 
     r_objid = ldm_relative (buffer, buflen, 0x18, 0);
     r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
     len     = r_name;
     if (len < 0)
         return false;
 
     len += VBLK_SIZE_DSK4;
     if (len != get_unaligned_be32(buffer + 0x14))
         return false;
 
     disk = &vb->vblk.disk;
     import_uuid(&disk->disk_id, buffer + 0x18 + r_name);
     return true;
 }
 
 /**
  * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Partition object (version 3) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Partition VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
 {
     int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
     struct vblk_part *part;
 
     BUG_ON(!buffer || !vb);
     r_objid = ldm_relative(buffer, buflen, 0x18, 0);
     if (r_objid < 0) {
         ldm_error("r_objid %d < 0", r_objid);
         return false;
     }
     r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
     if (r_name < 0) {
         ldm_error("r_name %d < 0", r_name);
         return false;
     }
     r_size = ldm_relative(buffer, buflen, 0x34, r_name);
     if (r_size < 0) {
         ldm_error("r_size %d < 0", r_size);
         return false;
     }
     r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
     if (r_parent < 0) {
         ldm_error("r_parent %d < 0", r_parent);
         return false;
     }
     r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
     if (r_diskid < 0) {
         ldm_error("r_diskid %d < 0", r_diskid);
         return false;
     }
     if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
         r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
         if (r_index < 0) {
             ldm_error("r_index %d < 0", r_index);
             return false;
         }
         len = r_index;
     } else
         len = r_diskid;
     if (len < 0) {
         ldm_error("len %d < 0", len);
         return false;
     }
     len += VBLK_SIZE_PRT3;
     if (len > get_unaligned_be32(buffer + 0x14)) {
         ldm_error("len %d > BE32(buffer + 0x14) %d", len,
                 get_unaligned_be32(buffer + 0x14));
         return false;
     }
     part = &vb->vblk.part;
     part->start = get_unaligned_be64(buffer + 0x24 + r_name);
     part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
     part->size = ldm_get_vnum(buffer + 0x34 + r_name);
     part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
     part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
     if (vb->flags & VBLK_FLAG_PART_INDEX)
         part->partnum = buffer[0x35 + r_diskid];
     else
         part->partnum = 0;
     return true;
 }
 
 /**
  * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
  * @buffer:  Block of data being worked on
  * @buflen:  Size of the block of data
  * @vb:      In-memory vblk in which to return information
  *
  * Read a raw VBLK Volume object (version 5) into a vblk structure.
  *
  * Return:  'true'   @vb contains a Volume VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
 {
     int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
     int r_id1, r_id2, r_size2, r_drive, len;
     struct vblk_volu *volu;
 
     BUG_ON(!buffer || !vb);
     r_objid = ldm_relative(buffer, buflen, 0x18, 0);
     if (r_objid < 0) {
         ldm_error("r_objid %d < 0", r_objid);
         return false;
     }
     r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
     if (r_name < 0) {
         ldm_error("r_name %d < 0", r_name);
         return false;
     }
     r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
     if (r_vtype < 0) {
         ldm_error("r_vtype %d < 0", r_vtype);
         return false;
     }
     r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
     if (r_disable_drive_letter < 0) {
         ldm_error("r_disable_drive_letter %d < 0",
                 r_disable_drive_letter);
         return false;
     }
     r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
     if (r_child < 0) {
         ldm_error("r_child %d < 0", r_child);
         return false;
     }
     r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
     if (r_size < 0) {
         ldm_error("r_size %d < 0", r_size);
         return false;
     }
     if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
         r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
         if (r_id1 < 0) {
             ldm_error("r_id1 %d < 0", r_id1);
             return false;
         }
     } else
         r_id1 = r_size;
     if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
         r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
         if (r_id2 < 0) {
             ldm_error("r_id2 %d < 0", r_id2);
             return false;
         }
     } else
         r_id2 = r_id1;
     if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
         r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
         if (r_size2 < 0) {
             ldm_error("r_size2 %d < 0", r_size2);
             return false;
         }
     } else
         r_size2 = r_id2;
     if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
         r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
         if (r_drive < 0) {
             ldm_error("r_drive %d < 0", r_drive);
             return false;
         }
     } else
         r_drive = r_size2;
     len = r_drive;
     if (len < 0) {
         ldm_error("len %d < 0", len);
         return false;
     }
     len += VBLK_SIZE_VOL5;
     if (len > get_unaligned_be32(buffer + 0x14)) {
         ldm_error("len %d > BE32(buffer + 0x14) %d", len,
                 get_unaligned_be32(buffer + 0x14));
         return false;
     }
     volu = &vb->vblk.volu;
     ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
             sizeof(volu->volume_type));
     memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
             sizeof(volu->volume_state));
     volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
     volu->partition_type = buffer[0x41 + r_size];
     memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
     if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
         ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
                 sizeof(volu->drive_hint));
     }
     return true;
 }
 
 /**
  * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
  * @buf:  Block of data being worked on
  * @len:  Size of the block of data
  * @vb:   In-memory vblk in which to return information
  *
  * Read a raw VBLK object into a vblk structure.  This function just reads the
  * information common to all VBLK types, then delegates the rest of the work to
  * helper functions: ldm_parse_*.
  *
  * Return:  'true'   @vb contains a VBLK
  *          'false'  @vb contents are not defined
  */
 static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
 {
     bool result = false;
     int r_objid;
 
     BUG_ON (!buf || !vb);
 
     r_objid = ldm_relative (buf, len, 0x18, 0);
     if (r_objid < 0) {
         ldm_error ("VBLK header is corrupt.");
         return false;
     }
 
     vb->flags  = buf[0x12];
     vb->type   = buf[0x13];
     vb->obj_id = ldm_get_vnum (buf + 0x18);
     ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
 
     switch (vb->type) {
         case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
         case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
         case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
         case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
         case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
         case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
         case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
     }
 
     if (result)
         ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
              (unsigned long long) vb->obj_id, vb->type);
     else
         ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
             (unsigned long long) vb->obj_id, vb->type);
 
     return result;
 }
 
 
 /**
  * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
  * @data:  Raw VBLK to add to the database
  * @len:   Size of the raw VBLK
  * @ldb:   Cache of the database structures
  *
  * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
  *
  * N.B.  This function does not check the validity of the VBLKs.
  *
  * Return:  'true'   The VBLK was added
  *          'false'  An error occurred
  */
 static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
 {
     struct vblk *vb;
     struct list_head *item;
 
     BUG_ON (!data || !ldb);
 
     vb = kmalloc (sizeof (*vb), GFP_KERNEL);
     if (!vb) {
         ldm_crit ("Out of memory.");
         return false;
     }
 
     if (!ldm_parse_vblk (data, len, vb)) {
         kfree(vb);
         return false;           /* Already logged */
     }
 
     /* Put vblk into the correct list. */
     switch (vb->type) {
     case VBLK_DGR3:
     case VBLK_DGR4:
         list_add (&vb->list, &ldb->v_dgrp);
         break;
     case VBLK_DSK3:
     case VBLK_DSK4:
         list_add (&vb->list, &ldb->v_disk);
         break;
     case VBLK_VOL5:
         list_add (&vb->list, &ldb->v_volu);
         break;
     case VBLK_CMP3:
         list_add (&vb->list, &ldb->v_comp);
         break;
     case VBLK_PRT3:
         /* Sort by the partition's start sector. */
         list_for_each (item, &ldb->v_part) {
             struct vblk *v = list_entry (item, struct vblk, list);
             if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
                 (v->vblk.part.start > vb->vblk.part.start)) {
                 list_add_tail (&vb->list, &v->list);
                 return true;
             }
         }
         list_add_tail (&vb->list, &ldb->v_part);
         break;
     }
     return true;
 }
 
 /**
  * ldm_frag_add - Add a VBLK fragment to a list
  * @data:   Raw fragment to be added to the list
  * @size:   Size of the raw fragment
  * @frags:  Linked list of VBLK fragments
  *
  * Fragmented VBLKs may not be consecutive in the database, so they are placed
  * in a list so they can be pieced together later.
  *
  * Return:  'true'   Success, the VBLK was added to the list
  *          'false'  Error, a problem occurred
  */
 static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
 {
     struct frag *f;
     struct list_head *item;
     int rec, num, group;
 
     BUG_ON (!data || !frags);
 
     if (size < 2 * VBLK_SIZE_HEAD) {
         ldm_error("Value of size is too small.");
         return false;
     }
 
     group = get_unaligned_be32(data + 0x08);
     rec   = get_unaligned_be16(data + 0x0C);
     num   = get_unaligned_be16(data + 0x0E);
     if ((num < 1) || (num > 4)) {
         ldm_error ("A VBLK claims to have %d parts.", num);
         return false;
     }
     if (rec >= num) {
         ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
         return false;
     }
 
     list_for_each (item, frags) {
         f = list_entry (item, struct frag, list);
         if (f->group == group)
             goto found;
     }
 
     f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
     if (!f) {
         ldm_crit ("Out of memory.");
         return false;
     }
 
     f->group = group;
     f->num   = num;
     f->rec   = rec;
     f->map   = 0xFF << num;
 
     list_add_tail (&f->list, frags);
 found:
     if (rec >= f->num) {
         ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
         return false;
     }
     if (f->map & (1 << rec)) {
         ldm_error ("Duplicate VBLK, part %d.", rec);
         f->map &= 0x7F;         /* Mark the group as broken */
         return false;
     }
     f->map |= (1 << rec);
     if (!rec)
         memcpy(f->data, data, VBLK_SIZE_HEAD);
     data += VBLK_SIZE_HEAD;
     size -= VBLK_SIZE_HEAD;
     memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
     return true;
 }
 
 /**
  * ldm_frag_free - Free a linked list of VBLK fragments
  * @list:  Linked list of fragments
  *
  * Free a linked list of VBLK fragments
  *
  * Return:  none
  */
 static void ldm_frag_free (struct list_head *list)
 {
     struct list_head *item, *tmp;
 
     BUG_ON (!list);
 
     list_for_each_safe (item, tmp, list)
         kfree (list_entry (item, struct frag, list));
 }
 
 /**
  * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
  * @frags:  Linked list of VBLK fragments
  * @ldb:    Cache of the database structures
  *
  * Now that all the fragmented VBLKs have been collected, they must be added to
  * the database for later use.
  *
  * Return:  'true'   All the fragments we added successfully
  *          'false'  One or more of the fragments we invalid
  */
 static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
 {
     struct frag *f;
     struct list_head *item;
 
     BUG_ON (!frags || !ldb);
 
     list_for_each (item, frags) {
         f = list_entry (item, struct frag, list);
 
         if (f->map != 0xFF) {
             ldm_error ("VBLK group %d is incomplete (0x%02x).",
                 f->group, f->map);
             return false;
         }
 
         if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
             return false;       /* Already logged */
     }
     return true;
 }
 
 /**
  * ldm_get_vblks - Read the on-disk database of VBLKs into memory
  * @state: Partition check state including device holding the LDM Database
  * @base:  Offset, into @state->disk, of the database
  * @ldb:   Cache of the database structures
  *
  * To use the information from the VBLKs, they need to be read from the disk,
  * unpacked and validated.  We cache them in @ldb according to their type.
  *
  * Return:  'true'   All the VBLKs were read successfully
  *          'false'  An error occurred
  */
 static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
               struct ldmdb *ldb)
 {
     int size, perbuf, skip, finish, s, v, recs;
     u8 *data = NULL;
     Sector sect;
     bool result = false;
     LIST_HEAD (frags);
 
     BUG_ON(!state || !ldb);
 
     size   = ldb->vm.vblk_size;
     perbuf = 512 / size;
     skip   = ldb->vm.vblk_offset >> 9;      /* Bytes to sectors */
     finish = (size * ldb->vm.last_vblk_seq) >> 9;
 
     for (s = skip; s < finish; s++) {       /* For each sector */
         data = read_part_sector(state, base + OFF_VMDB + s, &sect);
         if (!data) {
             ldm_crit ("Disk read failed.");
             goto out;
         }
 
         for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
             if (MAGIC_VBLK != get_unaligned_be32(data)) {
                 ldm_error ("Expected to find a VBLK.");
                 goto out;
             }
 
             recs = get_unaligned_be16(data + 0x0E); /* Number of records */
             if (recs == 1) {
                 if (!ldm_ldmdb_add (data, size, ldb))
                     goto out;   /* Already logged */
             } else if (recs > 1) {
                 if (!ldm_frag_add (data, size, &frags))
                     goto out;   /* Already logged */
             }
             /* else Record is not in use, ignore it. */
         }
         put_dev_sector (sect);
         data = NULL;
     }
 
     result = ldm_frag_commit (&frags, ldb); /* Failures, already logged */
 out:
     if (data)
         put_dev_sector (sect);
     ldm_frag_free (&frags);
 
     return result;
 }
 
 /**
  * ldm_free_vblks - Free a linked list of vblk's
  * @lh:  Head of a linked list of struct vblk
  *
  * Free a list of vblk's and free the memory used to maintain the list.
  *
  * Return:  none
  */
 static void ldm_free_vblks (struct list_head *lh)
 {
     struct list_head *item, *tmp;
 
     BUG_ON (!lh);
 
     list_for_each_safe (item, tmp, lh)
         kfree (list_entry (item, struct vblk, list));
 }
 
 
 /**
  * ldm_partition - Find out whether a device is a dynamic disk and handle it
  * @state: Partition check state including device holding the LDM Database
  *
  * This determines whether the device @bdev is a dynamic disk and if so creates
  * the partitions necessary in the gendisk structure pointed to by @hd.
  *
  * We create a dummy device 1, which contains the LDM database, and then create
  * each partition described by the LDM database in sequence as devices 2+. For
  * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
  * and so on: the actual data containing partitions.
  *
  * Return:  1 Success, @state->disk is a dynamic disk and we handled it
  *          0 Success, @state->disk is not a dynamic disk
  *         -1 An error occurred before enough information had been read
  *            Or @state->disk is a dynamic disk, but it may be corrupted
  */
 int ldm_partition(struct parsed_partitions *state)
 {
     struct ldmdb  *ldb;
     unsigned long base;
     int result = -1;
 
     BUG_ON(!state);
 
     /* Look for signs of a Dynamic Disk */
     if (!ldm_validate_partition_table(state))
         return 0;
 
     ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
     if (!ldb) {
         ldm_crit ("Out of memory.");
         goto out;
     }
 
     /* Parse and check privheads. */
     if (!ldm_validate_privheads(state, &ldb->ph))
         goto out;       /* Already logged */
 
     /* All further references are relative to base (database start). */
     base = ldb->ph.config_start;
 
     /* Parse and check tocs and vmdb. */
     if (!ldm_validate_tocblocks(state, base, ldb) ||
         !ldm_validate_vmdb(state, base, ldb))
             goto out;       /* Already logged */
 
     /* Initialize vblk lists in ldmdb struct */
     INIT_LIST_HEAD (&ldb->v_dgrp);
     INIT_LIST_HEAD (&ldb->v_disk);
     INIT_LIST_HEAD (&ldb->v_volu);
     INIT_LIST_HEAD (&ldb->v_comp);
     INIT_LIST_HEAD (&ldb->v_part);
 
     if (!ldm_get_vblks(state, base, ldb)) {
         ldm_crit ("Failed to read the VBLKs from the database.");
         goto cleanup;
     }
 
     /* Finally, create the data partition devices. */
     if (ldm_create_data_partitions(state, ldb)) {
         ldm_debug ("Parsed LDM database successfully.");
         result = 1;
     }
     /* else Already logged */
 
 cleanup:
     ldm_free_vblks (&ldb->v_dgrp);
     ldm_free_vblks (&ldb->v_disk);
     ldm_free_vblks (&ldb->v_volu);
     ldm_free_vblks (&ldb->v_comp);
     ldm_free_vblks (&ldb->v_part);
 out:
     kfree (ldb);
     return result;
 }

This page was automatically generated by the 2.1.0 LXR engine. The LXR team