[PATCH] NFSv4: Fix up races in nfs4_proc_setattr()
If we do not hold a valid stateid that is open for writes, there is little
point in doing an extra open of the file, as the RFC does not appear to
mandate this...
Make setattr use the correct stateid if we're holding mandatory byte
range locks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 91e7fe8..af80b59 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -756,11 +756,10 @@
fattr->valid = 0;
- if (state != NULL)
+ if (state != NULL) {
msg.rpc_cred = state->owner->so_cred;
- if (sattr->ia_valid & ATTR_SIZE)
- nfs4_copy_stateid(&arg.stateid, state, NULL);
- else
+ nfs4_copy_stateid(&arg.stateid, state, current->files);
+ } else
memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));
return rpc_call_sync(server->client, &msg, 0);
@@ -1124,47 +1123,31 @@
nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
struct iattr *sattr)
{
- struct inode * inode = dentry->d_inode;
- int size_change = sattr->ia_valid & ATTR_SIZE;
- struct nfs4_state *state = NULL;
- int need_iput = 0;
+ struct rpc_cred *cred;
+ struct inode *inode = dentry->d_inode;
+ struct nfs4_state *state;
int status;
fattr->valid = 0;
- if (size_change) {
- struct rpc_cred *cred = rpcauth_lookupcred(NFS_SERVER(inode)->client->cl_auth, 0);
- if (IS_ERR(cred))
- return PTR_ERR(cred);
+ cred = rpcauth_lookupcred(NFS_SERVER(inode)->client->cl_auth, 0);
+ if (IS_ERR(cred))
+ return PTR_ERR(cred);
+ /* Search for an existing WRITE delegation first */
+ state = nfs4_open_delegated(inode, FMODE_WRITE, cred);
+ if (!IS_ERR(state)) {
+ /* NB: nfs4_open_delegated() bumps the inode->i_count */
+ iput(inode);
+ } else {
+ /* Search for an existing open(O_WRITE) stateid */
state = nfs4_find_state(inode, cred, FMODE_WRITE);
- if (state == NULL) {
- state = nfs4_open_delegated(dentry->d_inode,
- FMODE_WRITE, cred);
- if (IS_ERR(state))
- state = nfs4_do_open(dentry->d_parent->d_inode,
- dentry, FMODE_WRITE,
- NULL, cred);
- need_iput = 1;
- }
- put_rpccred(cred);
- if (IS_ERR(state))
- return PTR_ERR(state);
-
- if (state->inode != inode) {
- printk(KERN_WARNING "nfs: raced in setattr (%p != %p), returning -EIO\n", inode, state->inode);
- status = -EIO;
- goto out;
- }
}
+
status = nfs4_do_setattr(NFS_SERVER(inode), fattr,
NFS_FH(inode), sattr, state);
-out:
- if (state) {
- inode = state->inode;
+ if (state != NULL)
nfs4_close_state(state, FMODE_WRITE);
- if (need_iput)
- iput(inode);
- }
+ put_rpccred(cred);
return status;
}