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Old 04-17-2008, 08:38 AM
 
Default Speed up gfs2_write_alloc_required, deprecate gfs2_extent_map

From: Steven Whitehouse <swhiteho@redhat.com>

This patch removes the call to gfs2_extent_map from gfs2_write_alloc_required,
instead we call gfs2_block_map directly. This results in fewer overall calls
to gfs2_block_map in the multi-block case.

Also, gfs2_extent_map is marked as deprecated so that people know that its
going away as soon as all the callers have been converted.

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

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index e9456eb..a25444a 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -548,6 +548,9 @@ out_fail:
return error;
}

+/*
+ * Deprecated: do not use in new code
+ */
int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)
{
struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 };
@@ -1197,10 +1200,9 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
unsigned int len, int *alloc_required)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
- u64 lblock, lblock_stop, dblock;
- u32 extlen;
- int new = 0;
- int error = 0;
+ struct buffer_head bh;
+ unsigned int shift;
+ u64 lblock, lblock_stop, size;

*alloc_required = 0;

@@ -1214,6 +1216,8 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
return 0;
}

+ *alloc_required = 1;
+ shift = sdp->sd_sb.sb_bsize_shift;
if (gfs2_is_dir(ip)) {
unsigned int bsize = sdp->sd_jbsize;
lblock = offset;
@@ -1221,27 +1225,25 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
lblock_stop = offset + len + bsize - 1;
do_div(lblock_stop, bsize);
} else {
- unsigned int shift = sdp->sd_sb.sb_bsize_shift;
u64 end_of_file = (ip->i_di.di_size + 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) {
- *alloc_required = 1;
+ if (lblock_stop > end_of_file)
return 0;
- }
}

- for (; lblock < lblock_stop; lblock += extlen) {
- error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
- if (error)
- return error;
-
- if (!dblock) {
- *alloc_required = 1;
+ size = (lblock_stop - lblock) << shift;
+ do {
+ bh.b_state = 0;
+ bh.b_size = size;
+ gfs2_block_map(&ip->i_inode, lblock, &bh, 0);
+ if (!buffer_mapped(&bh))
return 0;
- }
- }
+ size -= bh.b_size;
+ lblock += (bh.b_size >> ip->i_inode.i_blkbits);
+ } while(size > 0);

+ *alloc_required = 0;
return 0;
}

--
1.5.1.2
 

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