Add a lockless check for whether or not the page might be carrying
an existing writeback before we grab the inode->i_lock.
Reported-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/write.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 1d447e37f472..06e150c4e315 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -190,9 +190,11 @@ static struct nfs_page *nfs_page_find_head_request(struct page *page)
struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *req = NULL;
- spin_lock(&inode->i_lock);
- req = nfs_page_find_head_request_locked(NFS_I(inode), page);
- spin_unlock(&inode->i_lock);
+ if (PagePrivate(page) || PageSwapCache(page)) {
+ spin_lock(&inode->i_lock);
+ req = nfs_page_find_head_request_locked(NFS_I(inode), page);
+ spin_unlock(&inode->i_lock);
+ }
return req;
}
--
2.13.3
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