From: Alan Cox <alan@linux.intel.com>
Date: Sun, 21 May 2017 21:16:41 +0000 (+0100)
Subject: blkdev: allow for 16bit block counts
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=b771268a119530b711d9523644b3e619e1d1a403;p=FUZIX.git

blkdev: allow for 16bit block counts

On a 32bit system we can end up writing more than 256 blocks in a run when
we swap so blkdev needs to use 16bits for the block counter.

(We could make this a typedef for 8 v 16bit but it's not clear it matters
 enough)
---

diff --git a/Kernel/dev/blkdev.c b/Kernel/dev/blkdev.c
index 74fc3a0e..d78463d7 100644
--- a/Kernel/dev/blkdev.c
+++ b/Kernel/dev/blkdev.c
@@ -74,7 +74,8 @@ int blkdev_open(uint8_t minor, uint16_t flags)
 
 static int blkdev_transfer(uint8_t minor, uint8_t rawflag)
 {
-    uint8_t partition, n, count=0;
+    uint8_t partition, n;
+    uint16_t count = 0;
 
     /* we trust that blkdev_open() has already verified that this minor number is valid */
     blk_op.blkdev = &blkdev_table[minor >> 4];
diff --git a/Kernel/dev/blkdev.h b/Kernel/dev/blkdev.h
index e7098297..89c6320c 100644
--- a/Kernel/dev/blkdev.h
+++ b/Kernel/dev/blkdev.h
@@ -27,7 +27,7 @@ struct blkparam {
     uint8_t swap_page;                      /* page to pass to map_swap */
     blkdev_t *blkdev;                       /* active block device */
     uint32_t lba;                           /* LBA for first sectors to transfer */
-    uint8_t nblock;                         /* number of sectors to transfer */
+    uint16_t nblock;                        /* number of sectors to transfer */
     bool is_read;                           /* true: read sectors, false: write sectors */
 };
 /* macros that inline assembler code can use to access blkparam fields */