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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] lomount: Major rewrite: handle large files and GPT partition.
# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID fa143f374f3deac2c63b4f9585bb7e89d2d9614b
# Parent ef8d08aa2072b187a865f0827dc152fcc7afaf1d
lomount: Major rewrite: handle large files and GPT partition.
Signed-off-by: Tristan Gingold <tristan.gingold@xxxxxxxx>
---
tools/misc/lomount/lomount.c | 430 ++++++++++++++++++++++++++++---------------
1 files changed, 282 insertions(+), 148 deletions(-)
diff -r ef8d08aa2072 -r fa143f374f3d tools/misc/lomount/lomount.c
--- a/tools/misc/lomount/lomount.c Fri Jul 14 12:00:02 2006 +0100
+++ b/tools/misc/lomount/lomount.c Fri Jul 14 13:53:59 2006 +0100
@@ -4,6 +4,9 @@
* Copyright (c) 2004 Jim Brown
* Copyright (c) 2004 Brad Watson
* Copyright (c) 2004 Mulyadi Santosa
+ * Major rewrite by Tristan Gingold:
+ * - Handle GPT partitions
+ * - Handle large files
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
deal
@@ -41,6 +44,8 @@ enum
ERR_MOUNT // Other failure of mount command
};
+#define _LARGEFILE_SOURCE
+#define _FILE_OFFSET_BITS 64
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
@@ -63,22 +68,69 @@ struct pentry
unsigned char end_head;
unsigned int end_cylinder;
unsigned char end_sector;
- unsigned long start_sector_abs;
- unsigned long no_of_sectors_abs;
+ unsigned long long start_sector_abs;
+ unsigned long long no_of_sectors_abs;
};
-int loadptable(const char *diskimage, struct pentry parttbl[], struct pentry
**exttbl, int * valid)
+static void
+disp_entry (struct pentry *p)
+{
+ printf ("%10llu - %10llu: %02x %x\n",
+ SECSIZE * p->start_sector_abs,
+ SECSIZE * (p->start_sector_abs + p->no_of_sectors_abs - 1),
+ p->system,
+ p->bootable);
+}
+
+static unsigned long
+read_le4 (unsigned char *p)
+{
+ return (unsigned long) p[0]
+ | ((unsigned long) p[1] << 8)
+ | ((unsigned long) p[2] << 16)
+ | ((unsigned long) p[3] << 24);
+}
+
+static unsigned long long
+read_le8 (unsigned char *p)
+{
+ return (unsigned long long) p[0]
+ | ((unsigned long long) p[1] << 8)
+ | ((unsigned long long) p[2] << 16)
+ | ((unsigned long long) p[3] << 24)
+ | ((unsigned long long) p[4] << 32)
+ | ((unsigned long long) p[5] << 40)
+ | ((unsigned long long) p[6] << 48)
+ | ((unsigned long long) p[7] << 56);
+}
+
+/* Return true if the partition table is a GPT protective MBR. */
+static int
+check_gpt (struct pentry *part, int nbr_part)
+{
+ if (nbr_part != 4)
+ return 0;
+ if (part[0].system == 0xee
+ && part[1].no_of_sectors_abs == 0
+ && part[2].no_of_sectors_abs == 0
+ && part[3].no_of_sectors_abs == 0)
+ return 1;
+ return 0;
+}
+
+static int
+load_gpt (const char *diskimage, struct pentry *parttbl[])
{
FILE *fd;
size_t size;
- int fail = 1;
- int i, total_known_sectors = 0;
- unsigned char *pi;
- unsigned char data [SECSIZE];
- unsigned long extent = 0, old_extent = 0, e_count = 1;
- struct pentry exttbls[4];
-
- *valid = 0;
+ int fail = -1;
+ unsigned char data[SECSIZE];
+ unsigned long long entries_lba;
+ unsigned long entry_size;
+ struct pentry *part;
+ int nbr_part;
+ unsigned long long off;
+ int i;
fd = fopen(diskimage, "r");
if (fd == NULL)
@@ -86,108 +138,72 @@ int loadptable(const char *diskimage, st
perror(diskimage);
goto done;
}
+ fseeko (fd, SECSIZE, SEEK_SET);
size = fread (&data, 1, sizeof(data), fd);
if (size < (size_t)sizeof(data))
{
- fprintf(stderr, "Could not read the entire first sector of
%s.\n", diskimage);
- goto done;
- }
- for (i = 0; i < 4; i++)
- {
- pi = &data [446 + 16 * i];
- parttbl [i].bootable = *pi;
- parttbl [i].start_head = *(pi + 1);
- parttbl [i].start_cylinder = *(pi + 3) | ((*(pi + 2) << 2) &
0x300);
- parttbl [i].start_sector = *(pi + 2) & 0x3f;
- parttbl [i].system = *(pi + 4);
- parttbl [i].end_head = *(pi + 5);
- parttbl [i].end_cylinder = *(pi + 7) | ((*(pi + 6) << 2) &
0x300);
- parttbl [i].end_sector = *(pi + 6) & 0x3f;
- parttbl [i].start_sector_abs =
- (unsigned long) *(pi + 8) | ((unsigned long) *(pi + 9)
<< 8) | ((unsigned long) *(pi + 10) << 16) | ((unsigned long) *(pi + 11) << 24);
- parttbl [i].no_of_sectors_abs =
- (unsigned long) *(pi + 12) | ((unsigned long) *(pi +
13) << 8) | ((unsigned long) *(pi + 14) << 16) | ((unsigned long) *(pi + 15) <<
24);
- if (parttbl[i].system == 0xF || parttbl[i].system == 0x5)
- {
- extent = parttbl[i].start_sector_abs * SECSIZE;
- /* save the location of the "real" extended partition */
- old_extent = extent;
- }
- }
- *valid = (data [510] == 0x55 && data [511] == 0xaa) ? 1 : 0;
- for (i = 0; i < 4; i++)
- {
- total_known_sectors += parttbl[i].no_of_sectors_abs;
- }
- /* Extended Partition layout format was obtained from
- http://wigner.cped.ornl.gov/the-gang/att-0520/03-Partition.htm */
+ fprintf(stderr, "Could not read the GPT header of %s.\n",
+ diskimage);
+ goto done;
+ }
+
+ if (memcmp (data, "EFI PART", 8) != 0)
+ {
+ fprintf (stderr, "Bad GPT signature\n");
+ goto done;
+ }
+
+ entries_lba = read_le8 (&data[72]);
+ nbr_part = read_le4 (&data[80]);
+ entry_size = read_le4 (&data[84]);
+
#ifdef DEBUG
- if (extent != 0)
- {
- printf("extended partition detected at offset %ld\n", extent);
- }
+ fprintf(stderr, "lba entries: %lu, nbr_part: %u, entry_size: %lu\n",
+ entries_lba, nbr_part, entry_size);
#endif
- while (extent != 0)
- {
-/* according to realloc(3) passing NULL as pointer is same as calling malloc()
*/
- exttbl[0] = realloc(exttbl[0], e_count * sizeof(struct pentry));
- fseek(fd, extent, SEEK_SET);
- size = fread (&data, 1, sizeof(data), fd);
- if (size < (size_t)sizeof(data))
- {
- fprintf(stderr, "Could not read extended partition of
%s.", diskimage);
+ part = malloc (nbr_part * sizeof (struct pentry));
+ if (part == NULL)
+ {
+ fprintf(stderr,"Cannot allocate memory\n");
+ goto done;
+ }
+ memset (part, 0, nbr_part * sizeof (struct pentry));
+ *parttbl = part;
+
+ off = entries_lba * SECSIZE;
+ for (i = 0; i < nbr_part; i++)
+ {
+ static const char unused_guid[16] = {0};
+ fseeko (fd, off, SEEK_SET);
+ size = fread (&data, 1, 128, fd);
+ if (size < 128)
+ {
+ fprintf(stderr, "Could not read a GPT entry of %s.\n",
+ diskimage);
goto done;
}
- /* only first 2 entrys are used in extented partition tables */
- for (i = 0; i < 2; i++)
- {
- pi = &data [446 + 16 * i];
- exttbls [i].bootable = *pi;
- exttbls [i].start_head = *(pi + 1);
- exttbls [i].start_cylinder = *(pi + 3) | ((*(pi + 2) <<
2) & 0x300);
- exttbls [i].start_sector = *(pi + 2) & 0x3f;
- exttbls [i].system = *(pi + 4);
- exttbls [i].end_head = *(pi + 5);
- exttbls [i].end_cylinder = *(pi + 7) | ((*(pi + 6) <<
2) & 0x300);
- exttbls [i].end_sector = *(pi + 6) & 0x3f;
- exttbls [i].start_sector_abs =
- (unsigned long) *(pi + 8) | ((unsigned long)
*(pi + 9) << 8) | ((unsigned long) *(pi + 10) << 16) | ((unsigned long) *(pi +
11) << 24);
- exttbls [i].no_of_sectors_abs =
- (unsigned long) *(pi + 12) | ((unsigned long)
*(pi + 13) << 8) | ((unsigned long) *(pi + 14) << 16) | ((unsigned long) *(pi +
15) << 24);
- if (i == 0)
- {
- //memmove((void *)exttbl[e_count-1], (void
*)exttbls[i], sizeof(struct pentry));
- //memmove() seems broken!
- exttbl[0][e_count-1].bootable = exttbls
[i].bootable;
- exttbl[0][e_count-1].start_head = exttbls
[i].start_head;
- exttbl[0][e_count-1].start_cylinder = exttbls
[i].start_cylinder;
- exttbl[0][e_count-1].start_sector = exttbls
[i].start_sector;
- exttbl[0][e_count-1].system = exttbls
[i].system;
- exttbl[0][e_count-1].end_head = exttbls
[i].end_head;
- exttbl[0][e_count-1].end_cylinder = exttbls
[i].end_cylinder;
- exttbl[0][e_count-1].end_sector = exttbls
[i].end_sector;
- exttbl[0][e_count-1].start_sector_abs = exttbls
[i].start_sector_abs;
- exttbl[0][e_count-1].no_of_sectors_abs =
exttbls [i].no_of_sectors_abs;
- /* adjust for start of image instead of start of ext
partition */
- exttbl[0][e_count-1].start_sector_abs +=
(extent/SECSIZE);
+ if (memcmp (&data[0], unused_guid, 16) == 0)
+ {
+ part[i].start_sector_abs = 0;
+ part[i].no_of_sectors_abs = 0;
+ }
+ else
+ {
+ part[i].start_sector_abs = read_le8 (&data[32]);
+ part[i].no_of_sectors_abs = read_le8 (&data[40]);
#ifdef DEBUG
- printf("extent %ld start_sector_abs %ld\n",
extent, exttbl[0][e_count-1].start_sector_abs);
+ fprintf (stderr, "%d: %llu - %llu\n", i,
+ part[i].start_sector_abs,
+ part[i].no_of_sectors_abs);
#endif
- //else if (parttbl[i].system == 0x5)
- }
- else if (i == 1)
- {
- extent = (exttbls[i].start_sector_abs *
SECSIZE);
- if (extent)
- extent += old_extent;
- }
- }
- e_count ++;
- }
-#ifdef DEBUG
- printf("e_count = %ld\n", e_count);
-#endif
- fail = 0;
+ /* Convert end to a number. */
+ part[i].no_of_sectors_abs -=
+ part[i].start_sector_abs - 1;
+ }
+ off += entry_size;
+ }
+
+ fail = nbr_part;
done:
if (fd)
@@ -195,10 +211,115 @@ done:
return fail;
}
+/* Read an MBR entry. */
+static void
+read_mbr_record (unsigned char pi[16], struct pentry *res)
+{
+ res->bootable = *pi;
+ res->start_head = *(pi + 1);
+ res->start_cylinder = *(pi + 3) | ((*(pi + 2) << 2) & 0x300);
+ res->start_sector = *(pi + 2) & 0x3f;
+ res->system = *(pi + 4);
+ res->end_head = *(pi + 5);
+ res->end_cylinder = *(pi + 7) | ((*(pi + 6) << 2) & 0x300);
+ res->end_sector = *(pi + 6) & 0x3f;
+ res->start_sector_abs = read_le4 (&pi[8]);
+ res->no_of_sectors_abs = read_le4 (&pi[12]);
+}
+
+/* Returns the number of partitions, -1 in case of failure. */
+int load_mbr(const char *diskimage, struct pentry *parttbl[])
+{
+ FILE *fd;
+ size_t size;
+ int fail = -1;
+ int nbr_part;
+ int i;
+ unsigned char *pi;
+ unsigned char data [SECSIZE];
+ unsigned long long extent;
+ struct pentry *part;
+
+ nbr_part = 0;
+
+ fd = fopen(diskimage, "r");
+ if (fd == NULL)
+ {
+ perror(diskimage);
+ goto done;
+ }
+ size = fread (&data, 1, sizeof(data), fd);
+ if (size < (size_t)sizeof(data))
+ {
+ fprintf(stderr, "Could not read the entire first sector of
%s.\n", diskimage);
+ goto done;
+ }
+
+ if (data [510] != 0x55 || data [511] != 0xaa)
+ {
+ fprintf(stderr,"MBR signature mismatch (invalid partition
table?)\n");
+ goto done;
+ }
+
+ /* There is at most 4*4 + 4 = 20 entries, also there should be only
+ one extended partition. */
+ part = malloc (20 * sizeof (struct pentry));
+ if (part == NULL)
+ {
+ fprintf(stderr,"Cannot allocate memory\n");
+ goto done;
+ }
+ *parttbl = part;
+
+ /* Read MBR. */
+ nbr_part = 4;
+ for (i = 0; i < 4; i++)
+ {
+ pi = &data [446 + 16 * i];
+ read_mbr_record (pi, &part[i]);
+ }
+
+ /* Read extended partitions. */
+ for (i = 0; i < 4; i++)
+ {
+ if (part[i].system == 0xF || part[i].system == 0x5)
+ {
+ int j;
+
+ extent = part[i].start_sector_abs * SECSIZE;
+
+ fseeko (fd, extent, SEEK_SET);
+ size = fread (&data, 1, sizeof(data), fd);
+ if (size < (size_t)sizeof(data))
+ {
+ fprintf(stderr, "Could not read extended
partition of %s.", diskimage);
+ goto done;
+ }
+
+ for (j = 0; j < 4; j++)
+ {
+ int n;
+ pi = &data [446 + 16 * j];
+ n = nbr_part + j;
+ read_mbr_record (pi, &part[n]);
+ }
+
+ nbr_part += 4;
+ }
+ }
+
+ fail = nbr_part;
+
+done:
+ if (fd)
+ fclose(fd);
+ return fail;
+}
+
void usage(void)
{
- fprintf(stderr, "You must specify at least -diskimage and
-partition.\n");
- fprintf(stderr, "All other arguments are passed through to 'mount'.\n");
+ fprintf(stderr, "Usage: lomount [-verbose] [OPTIONS] -diskimage FILE
-partition NUM [OPTIONS]\n");
+ fprintf(stderr, "All OPTIONS are passed through to 'mount'.\n");
fprintf(stderr, "ex. lomount -t fs-type -diskimage hda.img -partition 1
/mnt\n");
exit(ERR_USAGE);
}
@@ -206,14 +327,17 @@ int main(int argc, char ** argv)
int main(int argc, char ** argv)
{
int status;
- struct pentry perttbl [4];
- struct pentry *exttbl[1], *parttbl;
+ int nbr_part;
+ struct pentry *parttbl;
char buf[BUF], argv2[BUF];
- const char * diskimage = 0;
- int partition = 0, sec, num = 0, pnum = 0, i, valid;
+ const char * diskimage = NULL;
+ int partition = 0;
+ unsigned long long sec, num, pnum;
+ int i;
size_t argv2_len = sizeof(argv2);
+ int verbose = 0;
+
argv2[0] = '\0';
- exttbl[0] = NULL;
for (i = 1; i < argc; i ++)
{
@@ -230,6 +354,10 @@ int main(int argc, char ** argv)
usage();
i++;
partition = atoi(argv[i]);
+ }
+ else if (strcmp(argv[i], "-verbose")==0)
+ {
+ verbose++;
}
else
{
@@ -241,59 +369,65 @@ int main(int argc, char ** argv)
len -= (len+1);
}
}
- if (! diskimage || partition < 1)
+ if (! diskimage || partition < 0)
usage();
- if (loadptable(diskimage, perttbl, exttbl, &valid))
+ nbr_part = load_mbr(diskimage, &parttbl);
+ if (check_gpt (parttbl, nbr_part)) {
+ free (parttbl);
+ nbr_part = load_gpt (diskimage, &parttbl);
+ }
+ if (nbr_part < 0)
return ERR_PART_PARSE;
- if (!valid)
- {
- fprintf(stderr, "Warning: disk image does not appear to
describe a valid partition table.\n");
+ if (partition == 0)
+ {
+ printf("Please specify a partition number. Table is:\n");
+ printf("Num Start - End OS Bootable\n");
+ for (i = 0; i < nbr_part; i++)
+ {
+ if (parttbl[i].no_of_sectors_abs != 0)
+ {
+ printf ("%2d: ", i + 1);
+ disp_entry (&parttbl[i]);
+ }
+ }
+ if (partition == 0)
+ return 0;
}
/* NOTE: need to make sure this always rounds down */
//sec = total_known_sectors / sizeof_diskimage;
-/* The above doesn't work unless the disk image is completely filled by
-partitions ... unused space will thrown off the sector size. The calculation
-assumes the disk image is completely filled, and that the few sectors used
-to store the partition table/MBR are few enough that the calculated value is
-off by (larger than) a value less than one. */
+ /* The above doesn't work unless the disk image is completely
+ filled by partitions ... unused space will thrown off the
+ sector size. The calculation assumes the disk image is
+ completely filled, and that the few sectors used to store
+ the partition table/MBR are few enough that the calculated
+ value is off by (larger than) a value less than one. */
sec = 512; /* TODO: calculate real sector size */
#ifdef DEBUG
printf("sec: %d\n", sec);
#endif
- if (partition > 4)
- {
- if (exttbl[0] == NULL)
- {
- fprintf(stderr, "No extended partitions were found in
%s.\n", diskimage);
- return ERR_NO_EPART;
- }
- parttbl = exttbl[0];
- if (parttbl[partition-5].no_of_sectors_abs == 0)
- {
- fprintf(stderr, "Partition %d was not found in %s.\n",
partition, diskimage);
- return ERR_NO_PART;
- }
- partition -= 4;
- }
- else
- {
- parttbl = perttbl;
- if (parttbl[partition-1].no_of_sectors_abs == 0)
- {
- fprintf(stderr, "Partition %d was not found in %s.\n",
partition, diskimage);
- return ERR_NO_PART;
- }
+ if (partition > nbr_part)
+ {
+ fprintf(stderr, "Bad partition number\n");
+ return ERR_NO_EPART;
}
num = parttbl[partition-1].start_sector_abs;
+ if (num == 0)
+ {
+ fprintf(stderr, "Partition %d was not found in %s.\n",
+ partition, diskimage);
+ return ERR_NO_PART;
+ }
+
pnum = sec * num;
#ifdef DEBUG
printf("offset = %d\n", pnum);
#endif
- snprintf(buf, sizeof(buf), "mount -oloop,offset=%d %s %s", pnum,
diskimage, argv2);
-#ifdef DEBUG
- printf("%s\n", buf);
-#endif
+ snprintf(buf, sizeof(buf), "mount -oloop,offset=%lld %s %s",
+ pnum, diskimage, argv2);
+ if (verbose)
+ printf("%s\n", buf);
+
status = system(buf);
if (WIFEXITED(status))
status = WEXITSTATUS(status);
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