Fwd: jffs2 & new linux zlib

[Clive Davies]

What, no comments at all? Shall I just check this in then? - it works for me.

Clive

----------  Forwarded Message  ----------

Subject: jffs2 & new linux zlib
Date: Tue, 19 Feb 2002 14:24:30 +0000
From: Clive Davies <cdavies at altera.com>
To: linux-mtd at lists.infradead.org

In testing jffs2 in linux 2.5.4-rmk1 I've found that kmalloc cannot allocate
objects of the size returned by zlib_deflate_workspacesize() and
zlib_inflate_workspacesize(). The patch below uses vmalloc to sucessfully
allocate the memory, however I'm not sure that this is the best approach.,
maybe it would be better to try and reduce the size of the deflate_workspace
& inflate workspace in zlib? (This might be a ridiculous idea, I haven't a
clue how zlib works) Any suggestions?

--- linux_2.5.4-rmk1/fs/jffs2/compr_zlib.c	Mon Feb 11 01:50:06 2002
+++ linux/fs/jffs2/compr_zlib.c	Tue Feb 19 13:33:24 2002
@@ -80,8 +80,7 @@ int zlib_compress(unsigned char *data_in
 		return -1;

 #ifdef __KERNEL__
-	strm.workspace = kmalloc(zlib_deflate_workspacesize(),
-				 GFP_KERNEL);
+	strm.workspace = vmalloc(zlib_deflate_workspacesize());
 	if (strm.workspace == NULL) {
 		printk(KERN_WARNING "deflateInit alloc of workspace failed\n");
 		return -1;
@@ -123,7 +122,7 @@ int zlib_compress(unsigned char *data_in

 	}
 	zlib_deflateEnd(&strm);
-	kfree(strm.workspace);
+	vfree(strm.workspace);

 	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", strm.total_in,
strm.total_out));

@@ -137,7 +136,7 @@ int zlib_compress(unsigned char *data_in

  out_err:
 	zlib_deflateEnd(&strm);
-	kfree(strm.workspace);
+	vfree(strm.workspace);
 	return -1;
 }

@@ -148,8 +147,7 @@ void zlib_decompress(unsigned char *data
 	int ret;

 #ifdef __KERNEL__
-	strm.workspace = kmalloc(zlib_inflate_workspacesize(),
-				 GFP_KERNEL);
+	strm.workspace = vmalloc(zlib_inflate_workspacesize());
 	if (strm.workspace == NULL) {
 		printk(KERN_WARNING "inflateInit alloc of workspace failed\n");
 		return;
@@ -177,5 +175,5 @@ void zlib_decompress(unsigned char *data
 		printk(KERN_NOTICE "inflate returned %d\n", ret);
 	}
 	zlib_inflateEnd(&strm);
-	kfree(strm.workspace);
+	vfree(strm.workspace);
 }

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