v4.19.13 snapshot.
diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
new file mode 100644
index 0000000..e285d6b
--- /dev/null
+++ b/fs/hpfs/buffer.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/hpfs/buffer.c
+ *
+ * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ * general buffer i/o
+ */
+#include <linux/sched.h>
+#include <linux/slab.h>
+#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;
+ struct blk_plug plug;
+
+ 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)) {
+ brelse(bh);
+ return;
+ }
+ brelse(bh);
+ };
+
+ blk_start_plug(&plug);
+ while (n > 0) {
+ if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
+ break;
+ sb_breadahead(s, secno);
+ secno++;
+ n--;
+ }
+ blk_finish_plug(&plug);
+}
+
+/* Map a sector into a buffer and return pointers to it and to the buffer. */
+
+void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
+ int ahead)
+{
+ struct buffer_head *bh;
+
+ hpfs_lock_assert(s);
+
+ hpfs_prefetch_sectors(s, secno, ahead);
+
+ cond_resched();
+
+ *bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno));
+ if (bh != NULL)
+ return bh->b_data;
+ else {
+ pr_err("%s(): read error\n", __func__);
+ return NULL;
+ }
+}
+
+/* Like hpfs_map_sector but don't read anything */
+
+void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
+{
+ struct buffer_head *bh;
+ /*return hpfs_map_sector(s, secno, bhp, 0);*/
+
+ hpfs_lock_assert(s);
+
+ cond_resched();
+
+ 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;
+ } else {
+ pr_err("%s(): getblk failed\n", __func__);
+ return NULL;
+ }
+}
+
+/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
+
+void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
+ int ahead)
+{
+ char *data;
+
+ hpfs_lock_assert(s);
+
+ cond_resched();
+
+ if (secno & 3) {
+ pr_err("%s(): unaligned read\n", __func__);
+ return NULL;
+ }
+
+ hpfs_prefetch_sectors(s, secno, 4 + ahead);
+
+ 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) &&
+ likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
+ return qbh->data = qbh->bh[0]->b_data;
+ }
+
+ qbh->data = data = kmalloc(2048, GFP_NOFS);
+ if (!data) {
+ pr_err("%s(): out of memory\n", __func__);
+ goto bail4;
+ }
+
+ memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
+ memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
+ memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
+ memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
+
+ return data;
+
+ bail4:
+ brelse(qbh->bh[3]);
+ bail3:
+ brelse(qbh->bh[2]);
+ bail2:
+ brelse(qbh->bh[1]);
+ bail1:
+ brelse(qbh->bh[0]);
+ bail0:
+ return NULL;
+}
+
+/* Don't read sectors */
+
+void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
+ struct quad_buffer_head *qbh)
+{
+ cond_resched();
+
+ hpfs_lock_assert(s);
+
+ if (secno & 3) {
+ pr_err("%s(): unaligned read\n", __func__);
+ return NULL;
+ }
+
+ if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0;
+ if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1;
+ if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2;
+ if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) 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) &&
+ likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
+ return qbh->data = qbh->bh[0]->b_data;
+ }
+
+ if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
+ pr_err("%s(): out of memory\n", __func__);
+ goto bail4;
+ }
+ return qbh->data;
+
+bail4:
+ brelse(qbh->bh[3]);
+bail3:
+ brelse(qbh->bh[2]);
+bail2:
+ brelse(qbh->bh[1]);
+bail1:
+ brelse(qbh->bh[0]);
+bail0:
+ return NULL;
+}
+
+
+void hpfs_brelse4(struct quad_buffer_head *qbh)
+{
+ if (unlikely(qbh->data != qbh->bh[0]->b_data))
+ kfree(qbh->data);
+ brelse(qbh->bh[0]);
+ brelse(qbh->bh[1]);
+ brelse(qbh->bh[2]);
+ brelse(qbh->bh[3]);
+}
+
+void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
+{
+ if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
+ memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
+ memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512);
+ memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
+ memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
+ }
+ mark_buffer_dirty(qbh->bh[0]);
+ mark_buffer_dirty(qbh->bh[1]);
+ mark_buffer_dirty(qbh->bh[2]);
+ mark_buffer_dirty(qbh->bh[3]);
+}