NFS: Fix double d_drop in nfs_instantiate() error path
If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning. But some callers already do a d_drop in the case
of an error return. Make certain we do only one d_drop in all error paths.
This issue was introduced because over time, the symlink proc API diverged
slightly from the create/mkdir/mknod proc API. To prevent other coding
mistakes of this type, change the symlink proc API to be more like
create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
routines so it is used in exactly the same way for create, mkdir, mknod,
and symlink.
Test plan:
Connectathon, all versions of NFS.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 084e8cb..affd3ae 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1147,23 +1147,20 @@
struct inode *dir = dentry->d_parent->d_inode;
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
if (error)
- goto out_err;
+ return error;
}
if (!(fattr->valid & NFS_ATTR_FATTR)) {
struct nfs_server *server = NFS_SB(dentry->d_sb);
error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
if (error < 0)
- goto out_err;
+ return error;
}
inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
error = PTR_ERR(inode);
if (IS_ERR(inode))
- goto out_err;
+ return error;
d_instantiate(dentry, inode);
return 0;
-out_err:
- d_drop(dentry);
- return error;
}
/*
@@ -1448,8 +1445,6 @@
nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
struct iattr attr;
- struct nfs_fattr sym_attr;
- struct nfs_fh sym_fh;
struct qstr qsymname;
int error;
@@ -1473,12 +1468,9 @@
lock_kernel();
nfs_begin_data_update(dir);
- error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
- &attr, &sym_fh, &sym_attr);
+ error = NFS_PROTO(dir)->symlink(dir, dentry, &qsymname, &attr);
nfs_end_data_update(dir);
if (!error)
- error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
- else
d_drop(dentry);
unlock_kernel();
return error;