[PATCH 08/21] nfs: clean up ->create in nfs_rpc_ops

From: Miklos Szeredi
Date: Tue Jun 05 2012 - 09:14:36 EST


From: Miklos Szeredi <mszeredi@xxxxxxx>

Don't pass nfs_open_context() to ->create(). Only the NFS4 implementation
needed that and only because it wanted to return an open file using open
intents. That task has been replaced by ->atomic_open so it is not necessary
anymore to pass the context to the create rpc operation.

Despite nfs4_proc_create apparently being okay with a NULL context it Oopses
somewhere down the call chain. So allocate a context here.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
CC: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
fs/nfs/dir.c | 42 ++----------------------------------------
fs/nfs/nfs3proc.c | 2 +-
fs/nfs/nfs4proc.c | 37 ++++++++++---------------------------
fs/nfs/proc.c | 2 +-
include/linux/nfs_xdr.h | 2 +-
5 files changed, 15 insertions(+), 70 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 0d8c712..45015d3 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -114,10 +114,8 @@ const struct inode_operations nfs3_dir_inode_operations = {
static struct file *nfs_atomic_open(struct inode *, struct dentry *,
struct opendata *, unsigned, umode_t,
bool *);
-static int nfs4_create(struct inode *dir, struct dentry *dentry,
- umode_t mode, struct nameidata *nd);
const struct inode_operations nfs4_dir_inode_operations = {
- .create = nfs4_create,
+ .create = nfs_create,
.lookup = nfs_lookup,
.atomic_open = nfs_atomic_open,
.link = nfs_link,
@@ -1582,42 +1580,6 @@ no_open:
return nfs_lookup_revalidate(dentry, nd);
}

-static int nfs4_create(struct inode *dir, struct dentry *dentry,
- umode_t mode, struct nameidata *nd)
-{
- struct nfs_open_context *ctx = NULL;
- struct iattr attr;
- int error;
- int open_flags = O_CREAT|O_EXCL;
-
- dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
- dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
-
- attr.ia_mode = mode;
- attr.ia_valid = ATTR_MODE;
-
- if (nd)
- open_flags = nd->intent.open.flags;
-
- ctx = create_nfs_open_context(dentry, open_flags);
- error = PTR_ERR(ctx);
- if (IS_ERR(ctx))
- goto out_err_drop;
-
- error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
- if (error != 0)
- goto out_put_ctx;
-
- put_nfs_open_context(ctx);
-
- return 0;
-out_put_ctx:
- put_nfs_open_context(ctx);
-out_err_drop:
- d_drop(dentry);
- return error;
-}
-
#endif /* CONFIG_NFSV4 */

/*
@@ -1684,7 +1646,7 @@ static int nfs_create(struct inode *dir, struct dentry *dentry,
if (nd)
open_flags = nd->intent.open.flags;

- error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL);
+ error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
if (error != 0)
goto out_err;
return 0;
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 2292a0f..3187e24 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -314,7 +314,7 @@ static void nfs3_free_createdata(struct nfs3_createdata *data)
*/
static int
nfs3_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
- int flags, struct nfs_open_context *ctx)
+ int flags)
{
struct nfs3_createdata *data;
umode_t mode = sattr->ia_mode;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d48dbef..267be3c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2779,37 +2779,22 @@ static int nfs4_proc_readlink(struct inode *inode, struct page *page,
}

/*
- * Got race?
- * We will need to arrange for the VFS layer to provide an atomic open.
- * Until then, this create/open method is prone to inefficiency and race
- * conditions due to the lookup, create, and open VFS calls from sys_open()
- * placed on the wire.
- *
- * Given the above sorry state of affairs, I'm simply sending an OPEN.
- * The file will be opened again in the subsequent VFS open call
- * (nfs4_proc_file_open).
- *
- * The open for read will just hang around to be used by any process that
- * opens the file O_RDONLY. This will all be resolved with the VFS changes.
+ * This is just for mknod. open(O_CREAT) will always do ->open_context().
*/
-
static int
nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
- int flags, struct nfs_open_context *ctx)
+ int flags)
{
- struct dentry *de = dentry;
+ struct nfs_open_context *ctx;
struct nfs4_state *state;
- struct rpc_cred *cred = NULL;
- fmode_t fmode = 0;
int status = 0;

- if (ctx != NULL) {
- cred = ctx->cred;
- de = ctx->dentry;
- fmode = ctx->mode;
- }
+ ctx = alloc_nfs_open_context(dentry, FMODE_READ);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
sattr->ia_mode &= ~current_umask();
- state = nfs4_do_open(dir, de, fmode, flags, sattr, cred, NULL);
+ state = nfs4_do_open(dir, dentry, ctx->mode, flags, sattr, ctx->cred, NULL);
d_drop(dentry);
if (IS_ERR(state)) {
status = PTR_ERR(state);
@@ -2817,11 +2802,9 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
}
d_add(dentry, igrab(state->inode));
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
- if (ctx != NULL)
- ctx->state = state;
- else
- nfs4_close_sync(state, fmode);
+ ctx->state = state;
out:
+ put_nfs_open_context(ctx);
return status;
}

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index a706b6b..81a0a42 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -259,7 +259,7 @@ static void nfs_free_createdata(const struct nfs_createdata *data)

static int
nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
- int flags, struct nfs_open_context *ctx)
+ int flags)
{
struct nfs_createdata *data;
struct rpc_message msg = {
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index d1a7bf5..660c0f5 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1371,7 +1371,7 @@ struct nfs_rpc_ops {
int (*readlink)(struct inode *, struct page *, unsigned int,
unsigned int);
int (*create) (struct inode *, struct dentry *,
- struct iattr *, int, struct nfs_open_context *);
+ struct iattr *, int);
int (*remove) (struct inode *, struct qstr *);
void (*unlink_setup) (struct rpc_message *, struct inode *dir);
void (*unlink_rpc_prepare) (struct rpc_task *, struct nfs_unlinkdata *);
--
1.7.7

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