GFS2: Streamline alloc calculations for writes
This patch removes some unused code, and make the calculation
of the number of blocks required conditional in order to reduce
the number of times this (potentially expensive) calculation
is done.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 789f28c..11ffc56 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1231,35 +1231,6 @@
}
/**
- * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file
- * @ip: the file
- * @len: the number of bytes to be written to the file
- * @data_blocks: returns the number of data blocks required
- * @ind_blocks: returns the number of indirect blocks required
- *
- */
-
-void gfs2_write_calc_reserv(struct gfs2_inode *ip, unsigned int len,
- unsigned int *data_blocks, unsigned int *ind_blocks)
-{
- struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
- unsigned int tmp;
-
- if (gfs2_is_dir(ip)) {
- *data_blocks = DIV_ROUND_UP(len, sdp->sd_jbsize) + 2;
- *ind_blocks = 3 * (sdp->sd_max_jheight - 1);
- } else {
- *data_blocks = (len >> sdp->sd_sb.sb_bsize_shift) + 3;
- *ind_blocks = 3 * (sdp->sd_max_height - 1);
- }
-
- for (tmp = *data_blocks; tmp > sdp->sd_diptrs;) {
- tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
- *ind_blocks += tmp;
- }
-}
-
-/**
* gfs2_write_alloc_required - figure out if a write will require an allocation
* @ip: the file being written to
* @offset: the offset to write to
@@ -1276,6 +1247,7 @@
struct buffer_head bh;
unsigned int shift;
u64 lblock, lblock_stop, size;
+ u64 end_of_file;
*alloc_required = 0;
@@ -1291,19 +1263,12 @@
*alloc_required = 1;
shift = sdp->sd_sb.sb_bsize_shift;
- if (gfs2_is_dir(ip)) {
- unsigned int bsize = sdp->sd_jbsize;
- lblock = offset;
- do_div(lblock, bsize);
- lblock_stop = offset + len + bsize - 1;
- do_div(lblock_stop, bsize);
- } else {
- u64 end_of_file = (ip->i_disksize + sdp->sd_sb.sb_bsize - 1) >> shift;
- lblock = offset >> shift;
- lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
- if (lblock_stop > end_of_file)
- return 0;
- }
+ BUG_ON(gfs2_is_dir(ip));
+ end_of_file = (ip->i_disksize + sdp->sd_sb.sb_bsize - 1) >> shift;
+ lblock = offset >> shift;
+ lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
+ if (lblock_stop > end_of_file)
+ return 0;
size = (lblock_stop - lblock) << shift;
do {