2014-11-05 14:37:55

by Peng Tao

[permalink] [raw]
Subject: [PATCH v2] nfs: fix pnfs direct write memory leak

For pNFS direct writes, layout driver may dynamically allocate ds_cinfo.buckets.
So we need to take care to free them when freeing dreq.

Ideally this needs to be done inside layout driver where ds_cinfo.buckets
are allocated. But buckets are attached to dreq and reused across LD IO iterations.
So I feel it's OK to free them in the generic layer.

Cc: [email protected] [v3.4+]
Signed-off-by: Peng Tao <[email protected]>
---
fs/nfs/direct.c | 1 +
include/linux/nfs_xdr.h | 9 +++++++++
2 files changed, 10 insertions(+)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 20cffc8..10bf072 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -266,6 +266,7 @@ static void nfs_direct_req_free(struct kref *kref)
{
struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref);

+ nfs_free_pnfs_ds_cinfo(&dreq->ds_cinfo);
if (dreq->l_ctx != NULL)
nfs_put_lock_context(dreq->l_ctx);
if (dreq->ctx != NULL)
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 983876f..10dee95 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1224,11 +1224,20 @@ struct nfs41_free_stateid_res {
unsigned int status;
};

+static inline void
+nfs_free_pnfs_ds_cinfo(struct pnfs_ds_commit_info *cinfo)
+{
+ kfree(cinfo->buckets);
+}
+
#else

struct pnfs_ds_commit_info {
};

+static inline void
+nfs_free_pnfs_ds_cinfo(struct pnfs_ds_commit_info *cinfo) {}
+
#endif /* CONFIG_NFS_V4_1 */

#ifdef CONFIG_NFS_V4_2
--
1.9.1