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NFSv4: fix open failure with O_ACCMODE flag

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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: ce4ef7c0a8 ("NFS: Split out NFS v4 file operations")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
ChenXiaoSong 2022-03-29 19:32:08 +08:00 committed by Trond Myklebust
parent ab0fc21bc7
commit b243874f6f
3 changed files with 14 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
fs/nfs/dir.c
View File

@ -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);

10
fs/nfs/internal.h
View File

@ -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.

6
fs/nfs/nfs4file.c
View File

@ -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;