From: ChenXiaoSong <chenxiaosong2@huawei.com>
Date: Tue, 29 Mar 2022 19:32:08 +0800
Subject: [PATCH] NFSv4: fix open failure with O_ACCMODE flag
Git-commit: b243874f6f9568b2daf1a00e9222cacdc15e159c
Patch-mainline: v5.18
References: git-fixes
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: ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: NeilBrown <neilb@suse.com>
---
fs/nfs/dir.c | 10 ----------
fs/nfs/internal.h | 10 ++++++++++
fs/nfs/nfs4file.c | 6 ++++--
3 files changed, 14 insertions(+), 12 deletions(-)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1847,16 +1847,6 @@ const struct dentry_operations nfs4_dent
};
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);
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -42,6 +42,16 @@ static inline bool nfs_lookup_is_soft_re
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.
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -32,6 +32,7 @@ nfs4_file_open(struct inode *inode, stru
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, stru
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, stru
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;