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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [fs/] [partitions/] [efi.c] - Rev 1765
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/************************************************************ * EFI GUID Partition Table handling * Per Intel EFI Specification v1.02 * http://developer.intel.com/technology/efi/efi.htm * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com> * Copyright 2000,2001,2002 Dell Computer Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * * TODO: * * Changelog: * Wed Mar 27 2002 Matt Domsch <Matt_Domsch@dell.com> * - Ported to 2.5.7-pre1 and 2.4.18 * - Applied patch to avoid fault in alternate header handling * - cleaned up find_valid_gpt * - On-disk structure and copy in memory is *always* LE now - * swab fields as needed * - remove print_gpt_header() * - only use first max_p partition entries, to keep the kernel minor number * and partition numbers tied. * - 2.4.18 patch needs own crc32() function - there's no official * lib/crc32.c in 2.4.x. * * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com> * - Removed __PRIPTR_PREFIX - not being used * * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com> * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied * * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com> * - Added compare_gpts(). * - moved le_efi_guid_to_cpus() back into this file. GPT is the only * thing that keeps EFI GUIDs on disk. * - Changed gpt structure names and members to be simpler and more Linux-like. * * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com> * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck * * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com> * - Changed function comments to DocBook style per Andreas Dilger suggestion. * * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com> * - Change read_lba() to use the page cache per Al Viro's work. * - print u64s properly on all architectures * - fixed debug_printk(), now Dprintk() * * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com> * - Style cleanups * - made most functions static * - Endianness addition * - remove test for second alternate header, as it's not per spec, * and is unnecessary. There's now a method to read/write the last * sector of an odd-sized disk from user space. No tools have ever * been released which used this code, so it's effectively dead. * - Per Asit Mallick of Intel, added a test for a valid PMBR. * - Added kernel command line option 'gpt' to override valid PMBR test. * * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com> * - added devfs volume UUID support (/dev/volumes/uuids) for * mounting file systems by the partition GUID. * * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com> * - Moved crc32() to linux/lib, added efi_crc32(). * * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com> * - Replaced Intel's CRC32 function with an equivalent * non-license-restricted version. * * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com> * - Fixed the last_lba() call to return the proper last block * * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com> * - Thanks to Andries Brouwer for his debugging assistance. * - Code works, detects all the partitions. * ************************************************************/ #include <linux/config.h> #include <linux/fs.h> #include <linux/genhd.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/string.h> #include <linux/blk.h> #include <linux/blkpg.h> #include <linux/slab.h> #include <linux/smp_lock.h> #include <linux/init.h> #include <linux/crc32.h> #include <asm/system.h> #include <asm/byteorder.h> #include "check.h" #include "efi.h" #if CONFIG_BLK_DEV_MD extern void md_autodetect_dev(kdev_t dev); #endif /* Handle printing of 64-bit values */ /* Borrowed from /usr/include/inttypes.h */ # if BITS_PER_LONG == 64 # define __PRI64_PREFIX "l" # else # define __PRI64_PREFIX "ll" # endif # define PRIx64 __PRI64_PREFIX "x" #undef EFI_DEBUG #ifdef EFI_DEBUG #define Dprintk(x...) printk(KERN_DEBUG x) #else #define Dprintk(x...) #endif /* This allows a kernel command line option 'gpt' to override * the test for invalid PMBR. Not __initdata because reloading * the partition tables happens after init too. */ static int force_gpt; static int __init force_gpt_fn(char *str) { force_gpt = 1; return 1; } __setup("gpt", force_gpt_fn); /** * efi_crc32() - EFI version of crc32 function * @buf: buffer to calculate crc32 of * @len - length of buf * * Description: Returns EFI-style CRC32 value for @buf * * This function uses the little endian Ethernet polynomial * but seeds the function with ~0, and xor's with ~0 at the end. * Note, the EFI Specification, v1.02, has a reference to * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). */ static inline u32 efi_crc32(const void *buf, unsigned long len) { return (crc32(~0L, buf, len) ^ ~0L); } /** * is_pmbr_valid(): test Protective MBR for validity * @mbr: pointer to a legacy mbr structure * * Description: Returns 1 if PMBR is valid, 0 otherwise. * Validity depends on two things: * 1) MSDOS signature is in the last two bytes of the MBR * 2) One partition of type 0xEE is found */ static int is_pmbr_valid(legacy_mbr *mbr) { int i, found = 0, signature = 0; if (!mbr) return 0; signature = (le16_to_cpu(mbr->signature) == MSDOS_MBR_SIGNATURE); for (i = 0; signature && i < 4; i++) { if (mbr->partition_record[i].sys_ind == EFI_PMBR_OSTYPE_EFI_GPT) { found = 1; break; } } return (signature && found); } /** * last_lba(): return number of last logical block of device * @hd: gendisk with partition list * @bdev: block device * * Description: Returns last LBA value on success, 0 on error. * This is stored (by sd and ide-geometry) in * the part[0] entry for this disk, and is the number of * physical sectors available on the disk. */ static u64 last_lba(struct gendisk *hd, struct block_device *bdev) { if (!hd || !hd->part || !bdev) return 0; return hd->part[MINOR(to_kdev_t(bdev->bd_dev))].nr_sects - 1; } /** * read_lba(): Read bytes from disk, starting at given LBA * @hd * @bdev * @lba * @buffer * @size_t * * Description: Reads @count bytes from @bdev into @buffer. * Returns number of bytes read on success, 0 on error. */ static size_t read_lba(struct gendisk *hd, struct block_device *bdev, u64 lba, u8 * buffer, size_t count) { size_t totalreadcount = 0, bytesread = 0; unsigned long blocksize; int i; Sector sect; unsigned char *data = NULL; if (!hd || !bdev || !buffer || !count) return 0; blocksize = get_hardsect_size(to_kdev_t(bdev->bd_dev)); if (!blocksize) blocksize = 512; for (i = 0; count > 0; i++) { data = read_dev_sector(bdev, lba, §); if (!data) return totalreadcount; bytesread = PAGE_CACHE_SIZE - (data - (unsigned char *) page_address(sect.v)); bytesread = min(bytesread, count); memcpy(buffer, data, bytesread); put_dev_sector(sect); buffer += bytesread; totalreadcount += bytesread; count -= bytesread; lba += (bytesread / blocksize); } return totalreadcount; } /** * alloc_read_gpt_entries(): reads partition entries from disk * @hd * @bdev * @gpt - GPT header * * Description: Returns ptes on success, NULL on error. * Allocates space for PTEs based on information found in @gpt. * Notes: remember to free pte when you're done! */ static gpt_entry * alloc_read_gpt_entries(struct gendisk *hd, struct block_device *bdev, gpt_header *gpt) { size_t count; gpt_entry *pte; if (!hd || !bdev || !gpt) return NULL; count = le32_to_cpu(gpt->num_partition_entries) * le32_to_cpu(gpt->sizeof_partition_entry); if (!count) return NULL; pte = kmalloc(count, GFP_KERNEL); if (!pte) return NULL; memset(pte, 0, count); if (read_lba(hd, bdev, le64_to_cpu(gpt->partition_entry_lba), (u8 *) pte, count) < count) { kfree(pte); pte=NULL; return NULL; } return pte; } /** * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk * @hd * @bdev * @lba is the Logical Block Address of the partition table * * Description: returns GPT header on success, NULL on error. Allocates * and fills a GPT header starting at @ from @bdev. * Note: remember to free gpt when finished with it. */ static gpt_header * alloc_read_gpt_header(struct gendisk *hd, struct block_device *bdev, u64 lba) { gpt_header *gpt; if (!hd || !bdev) return NULL; gpt = kmalloc(sizeof (gpt_header), GFP_KERNEL); if (!gpt) return NULL; memset(gpt, 0, sizeof (gpt_header)); if (read_lba(hd, bdev, lba, (u8 *) gpt, sizeof (gpt_header)) < sizeof (gpt_header)) { kfree(gpt); gpt=NULL; return NULL; } return gpt; } /** * is_gpt_valid() - tests one GPT header and PTEs for validity * @hd * @bdev * @lba is the logical block address of the GPT header to test * @gpt is a GPT header ptr, filled on return. * @ptes is a PTEs ptr, filled on return. * * Description: returns 1 if valid, 0 on error. * If valid, returns pointers to newly allocated GPT header and PTEs. */ static int is_gpt_valid(struct gendisk *hd, struct block_device *bdev, u64 lba, gpt_header **gpt, gpt_entry **ptes) { u32 crc, origcrc; if (!hd || !bdev || !gpt || !ptes) return 0; if (!(*gpt = alloc_read_gpt_header(hd, bdev, lba))) return 0; /* Check the GUID Partition Table signature */ if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { Dprintk("GUID Partition Table Header signature is wrong: %" PRIx64 " != %" PRIx64 "\n", le64_to_cpu((*gpt)->signature), GPT_HEADER_SIGNATURE); kfree(*gpt); *gpt = NULL; return 0; } /* Check the GUID Partition Table CRC */ origcrc = le32_to_cpu((*gpt)->header_crc32); (*gpt)->header_crc32 = 0; crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); if (crc != origcrc) { Dprintk ("GUID Partition Table Header CRC is wrong: %x != %x\n", crc, origcrc); kfree(*gpt); *gpt = NULL; return 0; } (*gpt)->header_crc32 = cpu_to_le32(origcrc); /* Check that the my_lba entry points to the LBA that contains * the GUID Partition Table */ if (le64_to_cpu((*gpt)->my_lba) != lba) { Dprintk("GPT my_lba incorrect: %" PRIx64 " != %" PRIx64 "\n", le64_to_cpu((*gpt)->my_lba), lba); kfree(*gpt); *gpt = NULL; return 0; } if (!(*ptes = alloc_read_gpt_entries(hd, bdev, *gpt))) { kfree(*gpt); *gpt = NULL; return 0; } /* Check the GUID Partition Entry Array CRC */ crc = efi_crc32((const unsigned char *) (*ptes), le32_to_cpu((*gpt)->num_partition_entries) * le32_to_cpu((*gpt)->sizeof_partition_entry)); if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { Dprintk("GUID Partitition Entry Array CRC check failed.\n"); kfree(*gpt); *gpt = NULL; kfree(*ptes); *ptes = NULL; return 0; } /* We're done, all's well */ return 1; } /** * compare_gpts() - Search disk for valid GPT headers and PTEs * @pgpt is the primary GPT header * @agpt is the alternate GPT header * @lastlba is the last LBA number * Description: Returns nothing. Sanity checks pgpt and agpt fields * and prints warnings on discrepancies. * */ static void compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) { int error_found = 0; if (!pgpt || !agpt) return; if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { printk(KERN_WARNING "GPT:Primary header LBA != Alt. header alternate_lba\n"); printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", le64_to_cpu(pgpt->my_lba), le64_to_cpu(agpt->alternate_lba)); error_found++; } if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { printk(KERN_WARNING "GPT:Primary header alternate_lba != Alt. header my_lba\n"); printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", le64_to_cpu(pgpt->alternate_lba), le64_to_cpu(agpt->my_lba)); error_found++; } if (le64_to_cpu(pgpt->first_usable_lba) != le64_to_cpu(agpt->first_usable_lba)) { printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n"); printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", le64_to_cpu(pgpt->first_usable_lba), le64_to_cpu(agpt->first_usable_lba)); error_found++; } if (le64_to_cpu(pgpt->last_usable_lba) != le64_to_cpu(agpt->last_usable_lba)) { printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n"); printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", le64_to_cpu(pgpt->last_usable_lba), le64_to_cpu(agpt->last_usable_lba)); error_found++; } if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { printk(KERN_WARNING "GPT:disk_guids don't match.\n"); error_found++; } if (le32_to_cpu(pgpt->num_partition_entries) != le32_to_cpu(agpt->num_partition_entries)) { printk(KERN_WARNING "GPT:num_partition_entries don't match: " "0x%x != 0x%x\n", le32_to_cpu(pgpt->num_partition_entries), le32_to_cpu(agpt->num_partition_entries)); error_found++; } if (le32_to_cpu(pgpt->sizeof_partition_entry) != le32_to_cpu(agpt->sizeof_partition_entry)) { printk(KERN_WARNING "GPT:sizeof_partition_entry values don't match: " "0x%x != 0x%x\n", le32_to_cpu(pgpt->sizeof_partition_entry), le32_to_cpu(agpt->sizeof_partition_entry)); error_found++; } if (le32_to_cpu(pgpt->partition_entry_array_crc32) != le32_to_cpu(agpt->partition_entry_array_crc32)) { printk(KERN_WARNING "GPT:partition_entry_array_crc32 values don't match: " "0x%x != 0x%x\n", le32_to_cpu(pgpt->partition_entry_array_crc32), le32_to_cpu(agpt->partition_entry_array_crc32)); error_found++; } if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { printk(KERN_WARNING "GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", le64_to_cpu(pgpt->alternate_lba), lastlba); error_found++; } if (le64_to_cpu(agpt->my_lba) != lastlba) { printk(KERN_WARNING "GPT:Alternate GPT header not at the end of the disk.\n"); printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", le64_to_cpu(agpt->my_lba), lastlba); error_found++; } if (error_found) printk(KERN_WARNING "GPT: Use GNU Parted to correct GPT errors.\n"); return; } /** * find_valid_gpt() - Search disk for valid GPT headers and PTEs * @hd * @bdev * @gpt is a GPT header ptr, filled on return. * @ptes is a PTEs ptr, filled on return. * Description: Returns 1 if valid, 0 on error. * If valid, returns pointers to newly allocated GPT header and PTEs. * Validity depends on finding either the Primary GPT header and PTEs valid, * or the Alternate GPT header and PTEs valid, and the PMBR valid. */ static int find_valid_gpt(struct gendisk *hd, struct block_device *bdev, gpt_header **gpt, gpt_entry **ptes) { int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; gpt_header *pgpt = NULL, *agpt = NULL; gpt_entry *pptes = NULL, *aptes = NULL; legacy_mbr *legacymbr = NULL; u64 lastlba; if (!hd || !bdev || !gpt || !ptes) return 0; lastlba = last_lba(hd, bdev); good_pgpt = is_gpt_valid(hd, bdev, GPT_PRIMARY_PARTITION_TABLE_LBA, &pgpt, &pptes); if (good_pgpt) { good_agpt = is_gpt_valid(hd, bdev, le64_to_cpu(pgpt->alternate_lba), &agpt, &aptes); if (!good_agpt) { good_agpt = is_gpt_valid(hd, bdev, lastlba, &agpt, &aptes); } } else { good_agpt = is_gpt_valid(hd, bdev, lastlba, &agpt, &aptes); } /* The obviously unsuccessful case */ if (!good_pgpt && !good_agpt) { goto fail; } /* This will be added to the EFI Spec. per Intel after v1.02. */ legacymbr = kmalloc(sizeof (*legacymbr), GFP_KERNEL); if (legacymbr) { memset(legacymbr, 0, sizeof (*legacymbr)); read_lba(hd, bdev, 0, (u8 *) legacymbr, sizeof (*legacymbr)); good_pmbr = is_pmbr_valid(legacymbr); kfree(legacymbr); legacymbr=NULL; } /* Failure due to bad PMBR */ if ((good_pgpt || good_agpt) && !good_pmbr && !force_gpt) { printk(KERN_WARNING " Warning: Disk has a valid GPT signature " "but invalid PMBR.\n"); printk(KERN_WARNING " Assuming this disk is *not* a GPT disk anymore.\n"); printk(KERN_WARNING " Use gpt kernel option to override. " "Use GNU Parted to correct disk.\n"); goto fail; } /* Would fail due to bad PMBR, but force GPT anyhow */ if ((good_pgpt || good_agpt) && !good_pmbr && force_gpt) { printk(KERN_WARNING " Warning: Disk has a valid GPT signature but " "invalid PMBR.\n"); printk(KERN_WARNING " Use GNU Parted to correct disk.\n"); printk(KERN_WARNING " gpt option taken, disk treated as GPT.\n"); } compare_gpts(pgpt, agpt, lastlba); /* The good cases */ if (good_pgpt && (good_pmbr || force_gpt)) { *gpt = pgpt; *ptes = pptes; if (agpt) { kfree(agpt); agpt = NULL; } if (aptes) { kfree(aptes); aptes = NULL; } if (!good_agpt) { printk(KERN_WARNING "Alternate GPT is invalid, " "using primary GPT.\n"); } return 1; } else if (good_agpt && (good_pmbr || force_gpt)) { *gpt = agpt; *ptes = aptes; if (pgpt) { kfree(pgpt); pgpt = NULL; } if (pptes) { kfree(pptes); pptes = NULL; } printk(KERN_WARNING "Primary GPT is invalid, using alternate GPT.\n"); return 1; } fail: if (pgpt) { kfree(pgpt); pgpt=NULL; } if (agpt) { kfree(agpt); agpt=NULL; } if (pptes) { kfree(pptes); pptes=NULL; } if (aptes) { kfree(aptes); aptes=NULL; } *gpt = NULL; *ptes = NULL; return 0; } /** * add_gpt_partitions(struct gendisk *hd, struct block_device *bdev, * @hd * @bdev * * Description: Create devices for each entry in the GUID Partition Table * Entries. * * We do not create a Linux partition for GPT, but * only for the actual data partitions. * Returns: * -1 if unable to read the partition table * 0 if this isn't our partition table * 1 if successful * */ static int add_gpt_partitions(struct gendisk *hd, struct block_device *bdev, int nextminor) { gpt_header *gpt = NULL; gpt_entry *ptes = NULL; u32 i; int max_p; if (!hd || !bdev) return -1; if (!find_valid_gpt(hd, bdev, &gpt, &ptes) || !gpt || !ptes) { if (gpt) { kfree(gpt); gpt = NULL; } if (ptes) { kfree(ptes); ptes = NULL; } return 0; } Dprintk("GUID Partition Table is valid! Yea!\n"); max_p = (1 << hd->minor_shift) - 1; for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < max_p; i++) { if (!efi_guidcmp(ptes[i].partition_type_guid, NULL_GUID)) continue; add_gd_partition(hd, nextminor+i, le64_to_cpu(ptes[i].starting_lba), (le64_to_cpu(ptes[i].ending_lba) - le64_to_cpu(ptes[i].starting_lba) + 1)); /* If there's this is a RAID volume, tell md */ #if CONFIG_BLK_DEV_MD if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) { md_autodetect_dev(MKDEV (MAJOR(to_kdev_t(bdev->bd_dev)), nextminor+i)); } #endif } kfree(ptes); ptes=NULL; kfree(gpt); gpt=NULL; printk("\n"); return 1; } /** * efi_partition(): EFI GPT partition handling entry function * @hd * @bdev * @first_sector: unused * @first_part_minor: minor number assigned to first GPT partition found * * Description: called from check.c, if the disk contains GPT * partitions, sets up partition entries in the kernel. * * If the first block on the disk is a legacy MBR, * it will get handled by msdos_partition(). * If it's a Protective MBR, we'll handle it here. * * set_blocksize() calls are necessary to be able to read * a disk with an odd number of 512-byte sectors, as the * default BLOCK_SIZE of 1024 bytes won't let that last * sector be read otherwise. * * Returns: * -1 if unable to read the partition table * 0 if this isn't our partitoin table * 1 if successful */ int efi_partition(struct gendisk *hd, struct block_device *bdev, unsigned long first_sector, int first_part_minor) { kdev_t dev = to_kdev_t(bdev->bd_dev); int hardblocksize = get_hardsect_size(dev); int orig_blksize_size = BLOCK_SIZE; int rc = 0; /* Need to change the block size that the block layer uses */ if (blksize_size[MAJOR(dev)]) { orig_blksize_size = blksize_size[MAJOR(dev)][MINOR(dev)]; } if (orig_blksize_size != hardblocksize) set_blocksize(dev, hardblocksize); rc = add_gpt_partitions(hd, bdev, first_part_minor); /* change back */ if (orig_blksize_size != hardblocksize) set_blocksize(dev, orig_blksize_size); return rc; }