[PATCH] v9fs: zero copy implementation
Performance enhancement reducing the number of copies in the data and
stat paths.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 3893dd3..ae6d032 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -37,8 +37,8 @@
#include "debug.h"
#include "v9fs.h"
#include "9p.h"
-#include "v9fs_vfs.h"
#include "conv.h"
+#include "v9fs_vfs.h"
#include "fid.h"
/**
@@ -77,17 +77,13 @@
unsigned int i, n, s;
int fid = -1;
int ret = 0;
- struct v9fs_stat *mi = NULL;
+ struct v9fs_stat stat;
int over = 0;
dprintk(DEBUG_VFS, "name %s\n", filp->f_dentry->d_name.name);
fid = file->fid;
- mi = kmalloc(v9ses->maxdata, GFP_KERNEL);
- if (!mi)
- return -ENOMEM;
-
if (file->rdir_fcall && (filp->f_pos != file->rdir_pos)) {
kfree(file->rdir_fcall);
file->rdir_fcall = NULL;
@@ -99,18 +95,18 @@
while (i < n) {
s = v9fs_deserialize_stat(
file->rdir_fcall->params.rread.data + i,
- n - i, mi, v9ses->maxdata, v9ses->extended);
+ n - i, &stat, v9ses->extended);
if (s == 0) {
dprintk(DEBUG_ERROR,
- "error while deserializing mistat\n");
+ "error while deserializing stat\n");
ret = -EIO;
goto FreeStructs;
}
- over = filldir(dirent, mi->name, strlen(mi->name),
- filp->f_pos, v9fs_qid2ino(&mi->qid),
- dt_type(mi));
+ over = filldir(dirent, stat.name.str, stat.name.len,
+ filp->f_pos, v9fs_qid2ino(&stat.qid),
+ dt_type(&stat));
if (over) {
file->rdir_fpos = i;
@@ -130,7 +126,7 @@
while (!over) {
ret = v9fs_t_read(v9ses, fid, filp->f_pos,
- v9ses->maxdata-V9FS_IOHDRSZ, &fcall);
+ v9ses->maxdata-V9FS_IOHDRSZ, &fcall);
if (ret < 0) {
dprintk(DEBUG_ERROR, "error while reading: %d: %p\n",
ret, fcall);
@@ -142,17 +138,17 @@
i = 0;
while (i < n) {
s = v9fs_deserialize_stat(fcall->params.rread.data + i,
- n - i, mi, v9ses->maxdata, v9ses->extended);
+ n - i, &stat, v9ses->extended);
if (s == 0) {
dprintk(DEBUG_ERROR,
- "error while deserializing mistat\n");
+ "error while deserializing stat\n");
return -EIO;
}
- over = filldir(dirent, mi->name, strlen(mi->name),
- filp->f_pos, v9fs_qid2ino(&mi->qid),
- dt_type(mi));
+ over = filldir(dirent, stat.name.str, stat.name.len,
+ filp->f_pos, v9fs_qid2ino(&stat.qid),
+ dt_type(&stat));
if (over) {
file->rdir_fcall = fcall;
@@ -171,7 +167,6 @@
FreeStructs:
kfree(fcall);
- kfree(mi);
return ret;
}