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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /fs/adfs/map.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'fs/adfs/map.c')
| -rw-r--r-- | fs/adfs/map.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/fs/adfs/map.c b/fs/adfs/map.c new file mode 100644 index 000000000..9d535a2ca --- /dev/null +++ b/fs/adfs/map.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/adfs/map.c + * + * Copyright (C) 1997-2002 Russell King + */ +#include <linux/slab.h> +#include <linux/statfs.h> +#include <linux/unaligned.h> +#include "adfs.h" + +/* + * The ADFS map is basically a set of sectors. Each sector is called a + * zone which contains a bitstream made up of variable sized fragments. + * Each bit refers to a set of bytes in the filesystem, defined by + * log2bpmb. This may be larger or smaller than the sector size, but + * the overall size it describes will always be a round number of + * sectors. A fragment id is always idlen bits long. + * + * < idlen > < n > <1> + * +---------+-------//---------+---+ + * | frag id | 0000....000000 | 1 | + * +---------+-------//---------+---+ + * + * The physical disk space used by a fragment is taken from the start of + * the fragment id up to and including the '1' bit - ie, idlen + n + 1 + * bits. + * + * A fragment id can be repeated multiple times in the whole map for + * large or fragmented files. The first map zone a fragment starts in + * is given by fragment id / ids_per_zone - this allows objects to start + * from any zone on the disk. + * + * Free space is described by a linked list of fragments. Each free + * fragment describes free space in the same way as the other fragments, + * however, the frag id specifies an offset (in map bits) from the end + * of this fragment to the start of the next free fragment. + * + * Objects stored on the disk are allocated object ids (we use these as + * our inode numbers.) Object ids contain a fragment id and an optional + * offset. This allows a directory fragment to contain small files + * associated with that directory. + */ + +/* + * For the future... + */ +static DEFINE_RWLOCK(adfs_map_lock); + +/* + * This is fun. We need to load up to 19 bits from the map at an + * arbitrary bit alignment. (We're limited to 19 bits by F+ version 2). + */ +#define GET_FRAG_ID(_map,_start,_idmask) \ + ({ \ + unsigned char *_m = _map + (_start >> 3); \ + u32 _frag = get_unaligned_le32(_m); \ + _frag >>= (_start & 7); \ + _frag & _idmask; \ + }) + +/* + * return the map bit offset of the fragment frag_id in the zone dm. + * Note that the loop is optimised for best asm code - look at the + * output of: + * gcc -D__KERNEL__ -O2 -I../../include -o - -S map.c + */ +static int lookup_zone(const struct adfs_discmap *dm, const unsigned int idlen, + const u32 frag_id, unsigned int *offset) +{ + const unsigned int endbit = dm->dm_endbit; + const u32 idmask = (1 << idlen) - 1; + unsigned char *map = dm->dm_bh->b_data; + unsigned int start = dm->dm_startbit; + unsigned int freelink, fragend; + u32 frag; + + frag = GET_FRAG_ID(map, 8, idmask & 0x7fff); + freelink = frag ? 8 + frag : 0; + + do { + frag = GET_FRAG_ID(map, start, idmask); + + fragend = find_next_bit_le(map, endbit, start + idlen); + if (fragend >= endbit) + goto error; + + if (start == freelink) { + freelink += frag & 0x7fff; + } else if (frag == frag_id) { + unsigned int length = fragend + 1 - start; + + if (*offset < length) + return start + *offset; + *offset -= length; + } + + start = fragend + 1; + } while (start < endbit); + return -1; + +error: + printk(KERN_ERR "adfs: oversized fragment 0x%x at 0x%x-0x%x\n", + frag, start, fragend); + return -1; +} + +/* + * Scan the free space map, for this zone, calculating the total + * number of map bits in each free space fragment. + * + * Note: idmask is limited to 15 bits [3.2] + */ +static unsigned int +scan_free_map(struct adfs_sb_info *asb, struct adfs_discmap *dm) +{ + const unsigned int endbit = dm->dm_endbit; + const unsigned int idlen = asb->s_idlen; + const unsigned int frag_idlen = idlen <= 15 ? idlen : 15; + const u32 idmask = (1 << frag_idlen) - 1; + unsigned char *map = dm->dm_bh->b_data; + unsigned int start = 8, fragend; + u32 frag; + unsigned long total = 0; + + /* + * get fragment id + */ + frag = GET_FRAG_ID(map, start, idmask); + + /* + * If the freelink is null, then no free fragments + * exist in this zone. + */ + if (frag == 0) + return 0; + + do { + start += frag; + + frag = GET_FRAG_ID(map, start, idmask); + + fragend = find_next_bit_le(map, endbit, start + idlen); + if (fragend >= endbit) + goto error; + + total += fragend + 1 - start; + } while (frag >= idlen + 1); + + if (frag != 0) + printk(KERN_ERR "adfs: undersized free fragment\n"); + + return total; +error: + printk(KERN_ERR "adfs: oversized free fragment\n"); + return 0; +} + +static int scan_map(struct adfs_sb_info *asb, unsigned int zone, + const u32 frag_id, unsigned int mapoff) +{ + const unsigned int idlen = asb->s_idlen; + struct adfs_discmap *dm, *dm_end; + int result; + + dm = asb->s_map + zone; + zone = asb->s_map_size; + dm_end = asb->s_map + zone; + + do { + result = lookup_zone(dm, idlen, frag_id, &mapoff); + + if (result != -1) + goto found; + + dm ++; + if (dm == dm_end) + dm = asb->s_map; + } while (--zone > 0); + + return -1; +found: + result -= dm->dm_startbit; + result += dm->dm_startblk; + + return result; +} + +/* + * calculate the amount of free blocks in the map. + * + * n=1 + * total_free = E(free_in_zone_n) + * nzones + */ +void adfs_map_statfs(struct super_block *sb, struct kstatfs *buf) +{ + struct adfs_sb_info *asb = ADFS_SB(sb); + struct adfs_discrecord *dr = adfs_map_discrecord(asb->s_map); + struct adfs_discmap *dm; + unsigned int total = 0; + unsigned int zone; + + dm = asb->s_map; + zone = asb->s_map_size; + + do { + total += scan_free_map(asb, dm++); + } while (--zone > 0); + + buf->f_blocks = adfs_disc_size(dr) >> sb->s_blocksize_bits; + buf->f_files = asb->s_ids_per_zone * asb->s_map_size; + buf->f_bavail = + buf->f_bfree = signed_asl(total, asb->s_map2blk); +} + +int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset) +{ + struct adfs_sb_info *asb = ADFS_SB(sb); + unsigned int zone, mapoff; + int result; + + /* + * map & root fragment is special - it starts in the center of the + * disk. The other fragments start at zone (frag / ids_per_zone) + */ + if (frag_id == ADFS_ROOT_FRAG) + zone = asb->s_map_size >> 1; + else + zone = frag_id / asb->s_ids_per_zone; + + if (zone >= asb->s_map_size) + goto bad_fragment; + + /* Convert sector offset to map offset */ + mapoff = signed_asl(offset, -asb->s_map2blk); + + read_lock(&adfs_map_lock); + result = scan_map(asb, zone, frag_id, mapoff); + read_unlock(&adfs_map_lock); + + if (result > 0) { + unsigned int secoff; + + /* Calculate sector offset into map block */ + secoff = offset - signed_asl(mapoff, asb->s_map2blk); + return secoff + signed_asl(result, asb->s_map2blk); + } + + adfs_error(sb, "fragment 0x%04x at offset %d not found in map", + frag_id, offset); + return 0; + +bad_fragment: + adfs_error(sb, "invalid fragment 0x%04x (zone = %d, max = %d)", + frag_id, zone, asb->s_map_size); + return 0; +} + +static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map) +{ + unsigned int v0, v1, v2, v3; + int i; + + v0 = v1 = v2 = v3 = 0; + for (i = sb->s_blocksize - 4; i; i -= 4) { + v0 += map[i] + (v3 >> 8); + v3 &= 0xff; + v1 += map[i + 1] + (v0 >> 8); + v0 &= 0xff; + v2 += map[i + 2] + (v1 >> 8); + v1 &= 0xff; + v3 += map[i + 3] + (v2 >> 8); + v2 &= 0xff; + } + v0 += v3 >> 8; + v1 += map[1] + (v0 >> 8); + v2 += map[2] + (v1 >> 8); + v3 += map[3] + (v2 >> 8); + + return v0 ^ v1 ^ v2 ^ v3; +} + +static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm) +{ + unsigned char crosscheck = 0, zonecheck = 1; + int i; + + for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) { + unsigned char *map; + + map = dm[i].dm_bh->b_data; + + if (adfs_calczonecheck(sb, map) != map[0]) { + adfs_error(sb, "zone %d fails zonecheck", i); + zonecheck = 0; + } + crosscheck ^= map[3]; + } + if (crosscheck != 0xff) + adfs_error(sb, "crosscheck != 0xff"); + return crosscheck == 0xff && zonecheck; +} + +/* + * Layout the map - the first zone contains a copy of the disc record, + * and the last zone must be limited to the size of the filesystem. + */ +static void adfs_map_layout(struct adfs_discmap *dm, unsigned int nzones, + struct adfs_discrecord *dr) +{ + unsigned int zone, zone_size; + u64 size; + + zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); + + dm[0].dm_bh = NULL; + dm[0].dm_startblk = 0; + dm[0].dm_startbit = 32 + ADFS_DR_SIZE_BITS; + dm[0].dm_endbit = 32 + zone_size; + + for (zone = 1; zone < nzones; zone++) { + dm[zone].dm_bh = NULL; + dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; + dm[zone].dm_startbit = 32; + dm[zone].dm_endbit = 32 + zone_size; + } + + size = adfs_disc_size(dr) >> dr->log2bpmb; + size -= (nzones - 1) * zone_size - ADFS_DR_SIZE_BITS; + dm[nzones - 1].dm_endbit = 32 + size; +} + +static int adfs_map_read(struct adfs_discmap *dm, struct super_block *sb, + unsigned int map_addr, unsigned int nzones) +{ + unsigned int zone; + + for (zone = 0; zone < nzones; zone++) { + dm[zone].dm_bh = sb_bread(sb, map_addr + zone); + if (!dm[zone].dm_bh) + return -EIO; + } + + return 0; +} + +static void adfs_map_relse(struct adfs_discmap *dm, unsigned int nzones) +{ + unsigned int zone; + + for (zone = 0; zone < nzones; zone++) + brelse(dm[zone].dm_bh); +} + +struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) +{ + struct adfs_sb_info *asb = ADFS_SB(sb); + struct adfs_discmap *dm; + unsigned int map_addr, zone_size, nzones; + int ret; + + nzones = dr->nzones | dr->nzones_high << 8; + zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); + + asb->s_idlen = dr->idlen; + asb->s_map_size = nzones; + asb->s_map2blk = dr->log2bpmb - dr->log2secsize; + asb->s_log2sharesize = dr->log2sharesize; + asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); + + map_addr = (nzones >> 1) * zone_size - + ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); + map_addr = signed_asl(map_addr, asb->s_map2blk); + + dm = kmalloc_objs(*dm, nzones); + if (dm == NULL) { + adfs_error(sb, "not enough memory"); + return ERR_PTR(-ENOMEM); + } + + adfs_map_layout(dm, nzones, dr); + + ret = adfs_map_read(dm, sb, map_addr, nzones); + if (ret) { + adfs_error(sb, "unable to read map"); + goto error_free; + } + + if (adfs_checkmap(sb, dm)) + return dm; + + adfs_error(sb, "map corrupted"); + +error_free: + adfs_map_relse(dm, nzones); + kfree(dm); + return ERR_PTR(-EIO); +} + +void adfs_free_map(struct super_block *sb) +{ + struct adfs_sb_info *asb = ADFS_SB(sb); + + adfs_map_relse(asb->s_map, asb->s_map_size); + kfree(asb->s_map); +} |
