On Tue, 2012-02-07 at 14:44 -0500, Trond Myklebust wrote:
> One way to easily shrink the size of that allocation is to convert the
> ih_name string into a pointer, and have the downcall allocate the
> storage for that string dynamically...
Like so....
8<-----------------------------------------------------------------------
>From 5221c8415957604507cd7408a695241096bcb3ad Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Date: Tue, 7 Feb 2012 14:59:05 -0500
Subject: [PATCH] NFSv4: Reduce the footprint of the idmapper
Instead of pre-allocating the storage for all the strings, we can
significantly reduce the size of that table by doing the allocation
when we do the downcall.
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
fs/nfs/idmap.c | 16 +++++++++++++---
1 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 5a5566f..fff7948 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -362,7 +362,7 @@ struct idmap_hashent {
unsigned long ih_expires;
__u32 ih_id;
size_t ih_namelen;
- char ih_name[IDMAP_NAMESZ];
+ const char *ih_name;
};
struct idmap_hashtable {
@@ -482,12 +482,17 @@ void
nfs_idmap_delete(struct nfs_client *clp)
{
struct idmap *idmap = clp->cl_idmap;
+ int i;
if (!idmap)
return;
nfs_idmap_unregister(clp, idmap->idmap_pipe);
rpc_destroy_pipe_data(idmap->idmap_pipe);
clp->cl_idmap = NULL;
+ for (i = 0; i < ARRAY_SIZE(idmap->idmap_user_hash.h_entries); i++)
+ kfree(idmap->idmap_user_hash.h_entries[i].ih_name);
+ for (i = 0; i < ARRAY_SIZE(idmap->idmap_group_hash.h_entries); i++)
+ kfree(idmap->idmap_group_hash.h_entries[i].ih_name);
kfree(idmap);
}
@@ -634,9 +639,14 @@ static void
idmap_update_entry(struct idmap_hashent *he, const char *name,
size_t namelen, __u32 id)
{
+ char *str = kmalloc(namelen + 1, GFP_KERNEL);
+ if (str == NULL)
+ return;
+ kfree(he->ih_name);
he->ih_id = id;
- memcpy(he->ih_name, name, namelen);
- he->ih_name[namelen] = '\0';
+ memcpy(str, name, namelen);
+ str[namelen] = '\0';
+ he->ih_name = str;
he->ih_namelen = namelen;
he->ih_expires = jiffies + nfs_idmap_cache_timeout;
}
--
1.7.7.6
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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