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-rw-r--r--fs/hpfs/buffer.c175
1 files changed, 175 insertions, 0 deletions
diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
new file mode 100644
index 0000000..2807aa8
--- /dev/null
+++ b/fs/hpfs/buffer.c
@@ -0,0 +1,175 @@
+/*
+ * linux/fs/hpfs/buffer.c
+ *
+ * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ * general buffer i/o
+ */
+
+#include "hpfs_fn.h"
+
+void hpfs_lock_creation(struct super_block *s)
+{
+#ifdef DEBUG_LOCKS
+ printk("lock creation\n");
+#endif
+ down(&hpfs_sb(s)->hpfs_creation_de);
+}
+
+void hpfs_unlock_creation(struct super_block *s)
+{
+#ifdef DEBUG_LOCKS
+ printk("unlock creation\n");
+#endif
+ up(&hpfs_sb(s)->hpfs_creation_de);
+}
+
+/* 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;
+
+ cond_resched();
+
+ *bhp = bh = sb_bread(s, secno);
+ if (bh != NULL)
+ return bh->b_data;
+ else {
+ printk("HPFS: hpfs_map_sector: read error\n");
+ 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);*/
+
+ 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 {
+ printk("HPFS: hpfs_get_sector: getblk failed\n");
+ 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)
+{
+ struct buffer_head *bh;
+ char *data;
+
+ cond_resched();
+
+ if (secno & 3) {
+ printk("HPFS: hpfs_map_4sectors: unaligned read\n");
+ return NULL;
+ }
+
+ qbh->data = data = (char *)kmalloc(2048, GFP_NOFS);
+ if (!data) {
+ printk("HPFS: hpfs_map_4sectors: out of memory\n");
+ goto bail;
+ }
+
+ qbh->bh[0] = bh = sb_bread(s, secno);
+ if (!bh)
+ goto bail0;
+ memcpy(data, bh->b_data, 512);
+
+ qbh->bh[1] = bh = sb_bread(s, secno + 1);
+ if (!bh)
+ goto bail1;
+ memcpy(data + 512, bh->b_data, 512);
+
+ qbh->bh[2] = bh = sb_bread(s, secno + 2);
+ if (!bh)
+ goto bail2;
+ memcpy(data + 2 * 512, bh->b_data, 512);
+
+ qbh->bh[3] = bh = sb_bread(s, secno + 3);
+ if (!bh)
+ goto bail3;
+ memcpy(data + 3 * 512, bh->b_data, 512);
+
+ return data;
+
+ bail3:
+ brelse(qbh->bh[2]);
+ bail2:
+ brelse(qbh->bh[1]);
+ bail1:
+ brelse(qbh->bh[0]);
+ bail0:
+ kfree(data);
+ printk("HPFS: hpfs_map_4sectors: read error\n");
+ bail:
+ return NULL;
+}
+
+/* Don't read sectors */
+
+void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
+ struct quad_buffer_head *qbh)
+{
+ cond_resched();
+
+ if (secno & 3) {
+ printk("HPFS: hpfs_get_4sectors: unaligned read\n");
+ return NULL;
+ }
+
+ /*return hpfs_map_4sectors(s, secno, qbh, 0);*/
+ if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
+ printk("HPFS: hpfs_get_4sectors: out of memory\n");
+ return NULL;
+ }
+ if (!(hpfs_get_sector(s, secno, &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;
+ memcpy(qbh->data, qbh->bh[0]->b_data, 512);
+ memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
+ memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
+ memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
+ return qbh->data;
+
+ 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)
+{
+ brelse(qbh->bh[3]);
+ brelse(qbh->bh[2]);
+ brelse(qbh->bh[1]);
+ brelse(qbh->bh[0]);
+ kfree(qbh->data);
+}
+
+void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
+{
+ PRINTK(("hpfs_mark_4buffers_dirty\n"));
+ memcpy(qbh->bh[0]->b_data, qbh->data, 512);
+ memcpy(qbh->bh[1]->b_data, qbh->data + 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]);
+}
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