From bc4866b6e0b44f8ea0df22a16e5927714beb4983 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 4 Oct 2010 17:59:08 -0400 Subject: [PATCH] NFS: Don't SIGBUS if nfs_vm_page_mkwrite races with a cache invalidation In the case where we lock the page, and then find out that the page has been thrown out of the page cache, we should just return VM_FAULT_NOPAGE. This is what block_page_mkwrite() does in these situations. Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- fs/nfs/file.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 59cbe1ba0511..39672b731736 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -551,7 +551,7 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) struct file *filp = vma->vm_file; struct dentry *dentry = filp->f_path.dentry; unsigned pagelen; - int ret = -EINVAL; + int ret = VM_FAULT_NOPAGE; struct address_space *mapping; dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n", @@ -567,21 +567,20 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) if (mapping != dentry->d_inode->i_mapping) goto out_unlock; - ret = 0; pagelen = nfs_page_length(page); if (pagelen == 0) goto out_unlock; - ret = nfs_flush_incompatible(filp, page); - if (ret != 0) - goto out_unlock; + ret = VM_FAULT_LOCKED; + if (nfs_flush_incompatible(filp, page) == 0 && + nfs_updatepage(filp, page, 0, pagelen) == 0) + goto out; - ret = nfs_updatepage(filp, page, 0, pagelen); + ret = VM_FAULT_SIGBUS; out_unlock: - if (!ret) - return VM_FAULT_LOCKED; unlock_page(page); - return VM_FAULT_SIGBUS; +out: + return ret; } static const struct vm_operations_struct nfs_file_vm_ops = {