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NFSv4: Fix problem with OPEN_DOWNGRADE

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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>
This commit is contained in:
Trond Myklebust 2005-11-04 15:33:38 -05:00
parent 4cecb76ff8
commit d530838bfa
7 changed files with 20 additions and 52 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
fs/nfs/inode.c
View file

@ -1009,13 +1009,18 @@ void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
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;

1
fs/nfs/nfs4_fs.h
View file

@ -247,7 +247,6 @@ extern void nfs4_drop_state_owner(struct nfs4_state_owner *);
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);

23
fs/nfs/nfs4proc.c
View file

@ -214,7 +214,7 @@ static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid,
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 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
{
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 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
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;
}

33
fs/nfs/nfs4state.c
View file

@ -383,28 +383,6 @@ nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
state->state = mode;
}
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)
{
@ -423,17 +401,6 @@ __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
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)
{

4
fs/nfs/read.c
View file

@ -507,7 +507,7 @@ int nfs_readpage(struct file *file, struct page *page)
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 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
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

2
fs/nfs/write.c
View file

@ -294,7 +294,7 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
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;

2
include/linux/nfs_fs.h
View file

@ -316,7 +316,7 @@ extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, st
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. */