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/inode.c b/fs/nfs/inode.c
index fc0f12b..24d2fbf 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1009,13 +1009,18 @@
spin_unlock(&inode->i_lock);
}
-struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode)
+/*
+ * Given an inode, search for an open context with the desired characteristics
+ */
+struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, int mode)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_open_context *pos, *ctx = NULL;
spin_lock(&inode->i_lock);
list_for_each_entry(pos, &nfsi->open_files, list) {
+ if (cred != NULL && pos->cred != cred)
+ continue;
if ((pos->mode & mode) == mode) {
ctx = get_nfs_open_context(pos);
break;
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 5396902..b7f262d 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -247,7 +247,6 @@
extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
extern void nfs4_put_open_state(struct nfs4_state *);
extern void nfs4_close_state(struct nfs4_state *, mode_t);
-extern struct nfs4_state *nfs4_find_state(struct inode *, struct rpc_cred *, mode_t mode);
extern void nfs4_state_set_mode_locked(struct nfs4_state *, mode_t);
extern void nfs4_schedule_state_recovery(struct nfs4_client *);
extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
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;
}
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 959374d..81d964b 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -384,28 +384,6 @@
}
static struct nfs4_state *
-__nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
-{
- struct nfs_inode *nfsi = NFS_I(inode);
- struct nfs4_state *state;
-
- mode &= (FMODE_READ|FMODE_WRITE);
- list_for_each_entry(state, &nfsi->open_states, inode_states) {
- if (state->owner->so_cred != cred)
- continue;
- if ((state->state & mode) != mode)
- continue;
- atomic_inc(&state->count);
- if (mode & FMODE_READ)
- state->nreaders++;
- if (mode & FMODE_WRITE)
- state->nwriters++;
- return state;
- }
- return NULL;
-}
-
-static struct nfs4_state *
__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
{
struct nfs_inode *nfsi = NFS_I(inode);
@@ -423,17 +401,6 @@
return NULL;
}
-struct nfs4_state *
-nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
-{
- struct nfs4_state *state;
-
- spin_lock(&inode->i_lock);
- state = __nfs4_find_state(inode, cred, mode);
- spin_unlock(&inode->i_lock);
- return state;
-}
-
static void
nfs4_free_open_state(struct nfs4_state *state)
{
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 43b03b1..5f20eaf 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -507,7 +507,7 @@
goto out_error;
if (file == NULL) {
- ctx = nfs_find_open_context(inode, FMODE_READ);
+ ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (ctx == NULL)
return -EBADF;
} else
@@ -576,7 +576,7 @@
nr_pages);
if (filp == NULL) {
- desc.ctx = nfs_find_open_context(inode, FMODE_READ);
+ desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (desc.ctx == NULL)
return -EBADF;
} else
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 819a65f..1bdbd4f 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -294,7 +294,7 @@
if (page->index >= end_index+1 || !offset)
goto out;
do_it:
- ctx = nfs_find_open_context(inode, FMODE_WRITE);
+ ctx = nfs_find_open_context(inode, NULL, FMODE_WRITE);
if (ctx == NULL) {
err = -EBADF;
goto out;
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 325fe7a..12787a9 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -316,7 +316,7 @@
extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
extern void put_nfs_open_context(struct nfs_open_context *ctx);
extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
-extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode);
+extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, int mode);
extern void nfs_file_clear_open_context(struct file *filp);
/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */