NFSv4: Fix problem with OPEN_DOWNGRADE
RFC 3530 states that for OPEN_DOWNGRADE "The share_access and share_deny
bits specified must be exactly equal to the union of the share_access and
share_deny bits specified for some subset of the OPENs in effect for
current openowner on the current file.
Setattr is currently violating the NFSv4 rules for OPEN_DOWNGRADE in that
it may cause a downgrade from OPEN4_SHARE_ACCESS_BOTH to
OPEN4_SHARE_ACCESS_WRITE despite the fact that there exists no open file
with O_WRONLY access mode.
Fix the problem by replacing nfs4_find_state() with a modified version of
nfs_find_open_context().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 02fddd0..9e492c2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -214,7 +214,7 @@
struct inode *inode = state->inode;
open_flags &= (FMODE_READ|FMODE_WRITE);
- /* Protect against nfs4_find_state() */
+ /* Protect against nfs4_find_state_byowner() */
spin_lock(&state->owner->so_lock);
spin_lock(&inode->i_lock);
memcpy(&state->stateid, stateid, sizeof(state->stateid));
@@ -1274,7 +1274,8 @@
{
struct rpc_cred *cred;
struct inode *inode = dentry->d_inode;
- struct nfs4_state *state;
+ struct nfs_open_context *ctx;
+ struct nfs4_state *state = NULL;
int status;
nfs_fattr_init(fattr);
@@ -1282,22 +1283,18 @@
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);
- }
+
+ /* Search for an existing open(O_WRITE) file */
+ ctx = nfs_find_open_context(inode, cred, FMODE_WRITE);
+ if (ctx != NULL)
+ state = ctx->state;
status = nfs4_do_setattr(NFS_SERVER(inode), fattr,
NFS_FH(inode), sattr, state);
if (status == 0)
nfs_setattr_update_inode(inode, sattr);
- if (state != NULL)
- nfs4_close_state(state, FMODE_WRITE);
+ if (ctx != NULL)
+ put_nfs_open_context(ctx);
put_rpccred(cred);
return status;
}