2008-06-12 19:33:58

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 01/37] NFS: Fix a preemption count leak in nfs_update_request

The commit 2785259631697ebb0749a3782cca206e2e542939 (nfs: use GFP_NOFS
preloads for radix-tree insertion) appears to have introduced a bug:
We only want to call radix_tree_preload() once after creating a request.
Calling it every time we loop after we created the request, will cause
preemption count leaks.

Signed-off-by: Trond Myklebust <[email protected]>
Cc: Nick Piggin <[email protected]>
---

fs/nfs/write.c | 11 ++++-------
1 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 6d8ace3..c2dd219 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -584,13 +584,6 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
/* Loop over all inode entries and see if we find
* A request for the page we wish to update
*/
- if (new) {
- if (radix_tree_preload(GFP_NOFS)) {
- nfs_release_request(new);
- return ERR_PTR(-ENOMEM);
- }
- }
-
spin_lock(&inode->i_lock);
req = nfs_page_find_request_locked(page);
if (req) {
@@ -630,6 +623,10 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
new = nfs_create_request(ctx, inode, page, offset, bytes);
if (IS_ERR(new))
return new;
+ if (radix_tree_preload(GFP_NOFS)) {
+ nfs_release_request(new);
+ return ERR_PTR(-ENOMEM);
+ }
}

/* We have a request for our page.