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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241// SPDX-License-Identifier: GPL-2.0/* * linux/fs/hfsplus/wrapper.c * * Copyright (C) 2001 * Brad Boyer (flar@allandria.com) * (C) 2003 Ardis Technologies <roman@ardistech.com> * * Handling of HFS wrappers around HFS+ volumes */
#include <linux/fs.h>#include <linux/blkdev.h>#include <linux/cdrom.h>#include <linux/unaligned.h>
#include "hfsplus_fs.h"#include "hfsplus_raw.h"
struct hfsplus_wd { u32 ablk_size; u16 ablk_start; u16 embed_start; u16 embed_count;};
/** * hfsplus_submit_bio - Perform block I/O * @sb: super block of volume for I/O * @sector: block to read or write, for blocks of HFSPLUS_SECTOR_SIZE bytes * @buf: buffer for I/O * @data: output pointer for location of requested data * @opf: I/O operation type and flags * * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads * @data will return a pointer to the start of the requested sector, * which may not be the same location as @buf. * * If @sector is not aligned to the bdev logical block size it will * be rounded down. For writes this means that @buf should contain data * that starts at the rounded-down address. As long as the data was * read using hfsplus_submit_bio() and the same buffer is used things * will work correctly. * * Returns: %0 on success else -errno code */int hfsplus_submit_bio(struct super_block *sb, sector_t sector, void *buf, void **data, blk_opf_t opf){ u64 io_size = hfsplus_min_io_size(sb); loff_t start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT; int offset = start & (io_size - 1);
if ((opf & REQ_OP_MASK) != REQ_OP_WRITE && data) *data = (u8 *)buf + offset;
/* * Align sector to hardware sector size and find offset. We assume that * io_size is a power of two, which _should_ be true. */ sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1); return bdev_rw_virt(sb->s_bdev, sector, buf, io_size, opf);}
static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd){ u32 extent; u16 attrib; __be16 sig;
sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG); if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) && sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) return 0;
attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB)); if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) || !(attrib & HFSP_WRAP_ATTRIB_SPARED)) return 0;
wd->ablk_size = be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE)); if (wd->ablk_size < HFSPLUS_SECTOR_SIZE) return 0; if (wd->ablk_size % HFSPLUS_SECTOR_SIZE) return 0; wd->ablk_start = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT); wd->embed_start = (extent >> 16) & 0xFFFF; wd->embed_count = extent & 0xFFFF;
return 1;}
static int hfsplus_get_last_session(struct super_block *sb, sector_t *start, sector_t *size){ struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
/* default values */ *start = 0; *size = bdev_nr_sectors(sb->s_bdev);
if (HFSPLUS_SB(sb)->session >= 0) { struct cdrom_tocentry te;
if (!cdi) return -EINVAL;
te.cdte_track = HFSPLUS_SB(sb)->session; te.cdte_format = CDROM_LBA; if (cdrom_read_tocentry(cdi, &te) || (te.cdte_ctrl & CDROM_DATA_TRACK) != 4) { pr_err("invalid session number or type of track\n"); return -EINVAL; } *start = (sector_t)te.cdte_addr.lba << 2; } else if (cdi) { struct cdrom_multisession ms_info;
ms_info.addr_format = CDROM_LBA; if (cdrom_multisession(cdi, &ms_info) == 0 && ms_info.xa_flag) *start = (sector_t)ms_info.addr.lba << 2; }
return 0;}
/* Find the volume header and fill in some minimum bits in superblock *//* Takes in super block, returns true if good data read */int hfsplus_read_wrapper(struct super_block *sb){ struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); struct hfsplus_wd wd; sector_t part_start, part_size; u32 blocksize; int error = 0;
error = -EINVAL; blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE); if (!blocksize) goto out;
sbi->min_io_size = blocksize;
if (hfsplus_get_last_session(sb, &part_start, &part_size)) goto out;
error = -ENOMEM; sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); if (!sbi->s_vhdr_buf) goto out; sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); if (!sbi->s_backup_vhdr_buf) goto out_free_vhdr;
reread: error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, sbi->s_vhdr_buf, (void **)&sbi->s_vhdr, REQ_OP_READ); if (error) goto out_free_backup_vhdr;
error = -EINVAL; switch (sbi->s_vhdr->signature) { case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX): set_bit(HFSPLUS_SB_HFSX, &sbi->flags); fallthrough; case cpu_to_be16(HFSPLUS_VOLHEAD_SIG): break; case cpu_to_be16(HFSP_WRAP_MAGIC): if (!hfsplus_read_mdb(sbi->s_vhdr, &wd)) goto out_free_backup_vhdr; wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT; part_start += (sector_t)wd.ablk_start + (sector_t)wd.embed_start * wd.ablk_size; part_size = (sector_t)wd.embed_count * wd.ablk_size; goto reread; default: /* * Check for a partition block. * * (should do this only for cdrom/loop though) */ if (hfs_part_find(sb, &part_start, &part_size)) goto out_free_backup_vhdr; goto reread; }
error = hfsplus_submit_bio(sb, part_start + part_size - 2, sbi->s_backup_vhdr_buf, (void **)&sbi->s_backup_vhdr, REQ_OP_READ); if (error) goto out_free_backup_vhdr;
error = -EINVAL; if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) { pr_warn("invalid secondary volume header\n"); goto out_free_backup_vhdr; }
blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
/* * Block size must be at least as large as a sector and a multiple of 2. */ if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize)) goto out_free_backup_vhdr; sbi->alloc_blksz = blocksize; sbi->alloc_blksz_shift = ilog2(blocksize); blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE);
/* * Align block size to block offset. */ while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1)) blocksize >>= 1;
if (sb_set_blocksize(sb, blocksize) != blocksize) { pr_err("unable to set blocksize to %u!\n", blocksize); goto out_free_backup_vhdr; }
sbi->blockoffset = part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT); sbi->part_start = part_start; sbi->sect_count = part_size; sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits; return 0;
out_free_backup_vhdr: kfree(sbi->s_backup_vhdr_buf);out_free_vhdr: kfree(sbi->s_vhdr_buf);out: return error;}