Commit b243874f authored by ChenXiaoSong's avatar ChenXiaoSong Committed by Trond Myklebust
Browse files

NFSv4: fix open failure with O_ACCMODE flag 



open() with O_ACCMODE|O_DIRECT flags secondly will fail.

Reproducer:
  1. mount -t nfs -o vers=4.2 $server_ip:/ /mnt/
  2. fd = open("/mnt/file", O_ACCMODE|O_DIRECT|O_CREAT)
  3. close(fd)
  4. fd = open("/mnt/file", O_ACCMODE|O_DIRECT)

Server nfsd4_decode_share_access() will fail with error nfserr_bad_xdr when
client use incorrect share access mode of 0.

Fix this by using NFS4_SHARE_ACCESS_BOTH share access mode in client,
just like firstly opening.

Fixes: ce4ef7c0 ("NFS: Split out NFS v4 file operations")
Signed-off-by: default avatarChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent ab0fc21b

fs/nfs/dir.c

+0 −10
Original line number Diff line number Diff line
@@ -1991,16 +1991,6 @@ const struct dentry_operations nfs4_dentry_operations = { 
};

EXPORT_SYMBOL_GPL(nfs4_dentry_operations);



static fmode_t flags_to_mode(int flags)

{

	fmode_t res = (__force fmode_t)flags & FMODE_EXEC;

	if ((flags & O_ACCMODE) != O_WRONLY)

		res |= FMODE_READ;

	if ((flags & O_ACCMODE) != O_RDONLY)

		res |= FMODE_WRITE;

	return res;

}



static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp)

{

	return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp);

fs/nfs/internal.h

+10 −0
Original line number Diff line number Diff line
@@ -42,6 +42,16 @@ static inline bool nfs_lookup_is_soft_revalidate(const struct dentry *dentry) 
	return true;

}



static inline fmode_t flags_to_mode(int flags)

{

	fmode_t res = (__force fmode_t)flags & FMODE_EXEC;

	if ((flags & O_ACCMODE) != O_WRONLY)

		res |= FMODE_READ;

	if ((flags & O_ACCMODE) != O_RDONLY)

		res |= FMODE_WRITE;

	return res;

}



/*

 * Note: RFC 1813 doesn't limit the number of auth flavors that

 * a server can return, so make something up.

fs/nfs/nfs4file.c

+4 −2
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ nfs4_file_open(struct inode *inode, struct file *filp) 
	struct dentry *parent = NULL;

	struct inode *dir;

	unsigned openflags = filp->f_flags;

	fmode_t f_mode;

	struct iattr attr;

	int err;
@@ -50,8 +51,9 @@ nfs4_file_open(struct inode *inode, struct file *filp) 
	if (err)

		return err;



	f_mode = filp->f_mode;

	if ((openflags & O_ACCMODE) == 3)

		openflags--;

		f_mode |= flags_to_mode(openflags);



	/* We can't create new files here */

	openflags &= ~(O_CREAT|O_EXCL);
@@ -59,7 +61,7 @@ nfs4_file_open(struct inode *inode, struct file *filp) 
	parent = dget_parent(dentry);

	dir = d_inode(parent);



	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);

	ctx = alloc_nfs_open_context(file_dentry(filp), f_mode, filp);

	err = PTR_ERR(ctx);

	if (IS_ERR(ctx))

		goto out;