Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / hpfs / buffer.c

diff --git a/kernel/fs/hpfs/buffer.c b/kernel/fs/hpfs/buffer.c
new file mode 100644 (file)
index 0000000..8057fe4
--- /dev/null
+++ b/kernel/fs/hpfs/buffer.c
@@ -0,0 +1,204 @@
+/*
+ *  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"
+
+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;
+
+       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, 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, 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 (!(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 (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]);
+}