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Diffstat (limited to 'fs/adfs/map.c')
-rw-r--r--fs/adfs/map.c247
1 files changed, 186 insertions, 61 deletions
diff --git a/fs/adfs/map.c b/fs/adfs/map.c
index f44d12cef5be..a81de80c45c1 100644
--- a/fs/adfs/map.c
+++ b/fs/adfs/map.c
@@ -4,6 +4,8 @@
*
* Copyright (C) 1997-2002 Russell King
*/
+#include <linux/slab.h>
+#include <linux/statfs.h>
#include <asm/unaligned.h>
#include "adfs.h"
@@ -66,54 +68,41 @@ static DEFINE_RWLOCK(adfs_map_lock);
static int lookup_zone(const struct adfs_discmap *dm, const unsigned int idlen,
const u32 frag_id, unsigned int *offset)
{
- const unsigned int mapsize = dm->dm_endbit;
+ const unsigned int endbit = dm->dm_endbit;
const u32 idmask = (1 << idlen) - 1;
- unsigned char *map = dm->dm_bh->b_data + 4;
+ unsigned char *map = dm->dm_bh->b_data;
unsigned int start = dm->dm_startbit;
- unsigned int mapptr;
+ 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);
- mapptr = start + idlen;
-
- /*
- * find end of fragment
- */
- {
- __le32 *_map = (__le32 *)map;
- u32 v = le32_to_cpu(_map[mapptr >> 5]) >> (mapptr & 31);
- while (v == 0) {
- mapptr = (mapptr & ~31) + 32;
- if (mapptr >= mapsize)
- goto error;
- v = le32_to_cpu(_map[mapptr >> 5]);
- }
-
- mapptr += 1 + ffz(~v);
+
+ 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;
}
- if (frag == frag_id)
- goto found;
-again:
- start = mapptr;
- } while (mapptr < mapsize);
+ 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, mapptr);
+ frag, start, fragend);
return -1;
-
-found:
- {
- int length = mapptr - start;
- if (*offset >= length) {
- *offset -= length;
- goto again;
- }
- }
- return start + *offset;
}
/*
@@ -125,12 +114,12 @@ found:
static unsigned int
scan_free_map(struct adfs_sb_info *asb, struct adfs_discmap *dm)
{
- const unsigned int mapsize = dm->dm_endbit + 32;
+ 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, mapptr;
+ unsigned int start = 8, fragend;
u32 frag;
unsigned long total = 0;
@@ -149,29 +138,13 @@ scan_free_map(struct adfs_sb_info *asb, struct adfs_discmap *dm)
do {
start += frag;
- /*
- * get fragment id
- */
frag = GET_FRAG_ID(map, start, idmask);
- mapptr = start + idlen;
-
- /*
- * find end of fragment
- */
- {
- __le32 *_map = (__le32 *)map;
- u32 v = le32_to_cpu(_map[mapptr >> 5]) >> (mapptr & 31);
- while (v == 0) {
- mapptr = (mapptr & ~31) + 32;
- if (mapptr >= mapsize)
- goto error;
- v = le32_to_cpu(_map[mapptr >> 5]);
- }
-
- mapptr += 1 + ffz(~v);
- }
- total += mapptr - start;
+ 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)
@@ -220,10 +193,10 @@ found:
* total_free = E(free_in_zone_n)
* nzones
*/
-unsigned int
-adfs_map_free(struct super_block *sb)
+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;
@@ -235,7 +208,10 @@ adfs_map_free(struct super_block *sb)
total += scan_free_map(asb, dm++);
} while (--zone > 0);
- return signed_asl(total, asb->s_map2blk);
+ 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)
@@ -280,3 +256,152 @@ bad_fragment:
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_array(nzones, sizeof(*dm), GFP_KERNEL);
+ 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);
+}
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-25 11:46:35 +0300