lkml.org 
[lkml]   [2008]   [Apr]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 15/48] [GFS2] Add consts to various bits of rgrp.c
Date
From: Steven Whitehouse <swhiteho@redhat.com>

There are a couple of routines which scan bitmaps where we can
mark the bitmaps const, plus a couple of call sites that can
be updated too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index da60ce8..5fd8710 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -126,23 +126,24 @@ static unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
* Return: the block number (bitmap buffer scope) that was found
*/

-static u32 gfs2_bitfit(unsigned char *buffer, unsigned int buflen, u32 goal,
- unsigned char old_state)
+static u32 gfs2_bitfit(const u8 *buffer, unsigned int buflen, u32 goal,
+ u8 old_state)
{
- unsigned char *byte;
+ const u8 *byte;
u32 blk = goal;
unsigned int bit, bitlong;
- unsigned long *plong, plong55;
+ const unsigned long *plong;
+#if BITS_PER_LONG == 32
+ const unsigned long plong55 = 0x55555555;
+#else
+ const unsigned long plong55 = 0x5555555555555555;
+#endif

byte = buffer + (goal / GFS2_NBBY);
- plong = (unsigned long *)(buffer + (goal / GFS2_NBBY));
+ plong = (const unsigned long *)(buffer + (goal / GFS2_NBBY));
bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE;
bitlong = bit;
-#if BITS_PER_LONG == 32
- plong55 = 0x55555555;
-#else
- plong55 = 0x5555555555555555;
-#endif
+
while (byte < buffer + buflen) {

if (bitlong == 0 && old_state == 0 && *plong == plong55) {
@@ -179,14 +180,14 @@ static u32 gfs2_bitfit(unsigned char *buffer, unsigned int buflen, u32 goal,
* Returns: The number of bits
*/

-static u32 gfs2_bitcount(struct gfs2_rgrpd *rgd, unsigned char *buffer,
- unsigned int buflen, unsigned char state)
+static u32 gfs2_bitcount(struct gfs2_rgrpd *rgd, const u8 *buffer,
+ unsigned int buflen, u8 state)
{
- unsigned char *byte = buffer;
- unsigned char *end = buffer + buflen;
- unsigned char state1 = state << 2;
- unsigned char state2 = state << 4;
- unsigned char state3 = state << 6;
+ const u8 *byte = buffer;
+ const u8 *end = buffer + buflen;
+ const u8 state1 = state << 2;
+ const u8 state2 = state << 4;
+ const u8 state3 = state << 6;
u32 count = 0;

for (; byte < end; byte++) {
@@ -1327,12 +1328,11 @@ static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,
for (x = 0; x <= length; x++) {
/* The GFS2_BLKST_UNLINKED state doesn't apply to the clone
bitmaps, so we must search the originals for that. */
+ const u8 *buffer = bi->bi_bh->b_data + bi->bi_offset;
if (old_state != GFS2_BLKST_UNLINKED && bi->bi_clone)
- blk = gfs2_bitfit(bi->bi_clone + bi->bi_offset,
- bi->bi_len, goal, old_state);
- else
- blk = gfs2_bitfit(bi->bi_bh->b_data + bi->bi_offset,
- bi->bi_len, goal, old_state);
+ buffer = bi->bi_clone + bi->bi_offset;
+
+ blk = gfs2_bitfit(buffer, bi->bi_len, goal, old_state);
if (blk != BFITNOENT)
break;

--
1.5.1.2


\
 
 \ /
  Last update: 2008-04-17 11:43    [W:0.370 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site