hpfs: support hotfixes
When the OS/2 driver hits a disk write error, it writes the sector to
another location and adds the sector mapping to the hotfix map.
This patch makes the hpfs driver understand the hotfix map and remap
accesses accoring to it.
Signed-off-by: Mikulas Patocka <mikulas@twibright.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
index 8057fe4..f626114 100644
--- a/fs/hpfs/buffer.c
+++ b/fs/hpfs/buffer.c
@@ -10,6 +10,30 @@
#include <linux/blkdev.h>
#include "hpfs_fn.h"
+secno hpfs_search_hotfix_map(struct super_block *s, secno sec)
+{
+ unsigned i;
+ struct hpfs_sb_info *sbi = hpfs_sb(s);
+ for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
+ if (sbi->hotfix_from[i] == sec) {
+ return sbi->hotfix_to[i];
+ }
+ }
+ return sec;
+}
+
+unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n)
+{
+ unsigned i;
+ struct hpfs_sb_info *sbi = hpfs_sb(s);
+ for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
+ if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) {
+ n = sbi->hotfix_from[i] - sec;
+ }
+ }
+ return n;
+}
+
void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
{
struct buffer_head *bh;
@@ -18,6 +42,9 @@
if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size))
return;
+ if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n))
+ return;
+
bh = sb_find_get_block(s, secno);
if (bh) {
if (buffer_uptodate(bh)) {
@@ -51,7 +78,7 @@
cond_resched();
- *bhp = bh = sb_bread(s, secno);
+ *bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno));
if (bh != NULL)
return bh->b_data;
else {
@@ -71,7 +98,7 @@
cond_resched();
- if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
+ if ((*bhp = bh = sb_getblk(s, hpfs_search_hotfix_map(s, secno))) != NULL) {
if (!buffer_uptodate(bh)) wait_on_buffer(bh);
set_buffer_uptodate(bh);
return bh->b_data;
@@ -99,10 +126,10 @@
hpfs_prefetch_sectors(s, secno, 4 + ahead);
- if (!(qbh->bh[0] = sb_bread(s, secno + 0))) goto bail0;
- if (!(qbh->bh[1] = sb_bread(s, secno + 1))) goto bail1;
- if (!(qbh->bh[2] = sb_bread(s, secno + 2))) goto bail2;
- if (!(qbh->bh[3] = sb_bread(s, secno + 3))) goto bail3;
+ if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0;
+ if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1;
+ if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2;
+ if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3;
if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&