Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  posix_acl: de-union a_refcount and a_rcu
  nfs_atomic_open(): prevent parallel nfs_lookup() on a negative hashed
  Use the right predicate in ->atomic_open() instances
This commit is contained in:
Linus Torvalds 2016-07-12 16:49:01 +09:00
commit 08d27eb206
8 changed files with 34 additions and 14 deletions

View file

@ -853,7 +853,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
struct p9_fid *fid, *inode_fid;
struct dentry *res = NULL;
if (d_unhashed(dentry)) {
if (d_in_lookup(dentry)) {
res = v9fs_vfs_lookup(dir, dentry, 0);
if (IS_ERR(res))
return PTR_ERR(res);

View file

@ -254,7 +254,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
struct posix_acl *pacl = NULL, *dacl = NULL;
struct dentry *res = NULL;
if (d_unhashed(dentry)) {
if (d_in_lookup(dentry)) {
res = v9fs_vfs_lookup(dir, dentry, 0);
if (IS_ERR(res))
return PTR_ERR(res);

View file

@ -394,7 +394,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
if (d_unhashed(dentry)) {
if (d_in_lookup(dentry)) {
dn = ceph_finish_lookup(req, dentry, err);
if (IS_ERR(dn))
err = PTR_ERR(dn);

View file

@ -445,7 +445,7 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
* Check for hashed negative dentry. We have already revalidated
* the dentry and it is fine. No need to perform another lookup.
*/
if (!d_unhashed(direntry))
if (!d_in_lookup(direntry))
return -ENOENT;
res = cifs_lookup(inode, direntry, 0);

View file

@ -480,7 +480,7 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
struct fuse_conn *fc = get_fuse_conn(dir);
struct dentry *res = NULL;
if (d_unhashed(entry)) {
if (d_in_lookup(entry)) {
res = fuse_lookup(dir, entry, 0);
if (IS_ERR(res))
return PTR_ERR(res);

View file

@ -1189,7 +1189,7 @@ static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
struct dentry *d;
bool excl = !!(flags & O_EXCL);
if (!d_unhashed(dentry))
if (!d_in_lookup(dentry))
goto skip_lookup;
d = __gfs2_lookup(dir, dentry, file, opened);

View file

@ -1485,11 +1485,13 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
struct file *file, unsigned open_flags,
umode_t mode, int *opened)
{
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
struct nfs_open_context *ctx;
struct dentry *res;
struct iattr attr = { .ia_valid = ATTR_OPEN };
struct inode *inode;
unsigned int lookup_flags = 0;
bool switched = false;
int err;
/* Expect a negative dentry */
@ -1504,7 +1506,7 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
/* NFS only supports OPEN on regular files */
if ((open_flags & O_DIRECTORY)) {
if (!d_unhashed(dentry)) {
if (!d_in_lookup(dentry)) {
/*
* Hashed negative dentry with O_DIRECTORY: dentry was
* revalidated and is fine, no need to perform lookup
@ -1528,6 +1530,17 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
attr.ia_size = 0;
}
if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) {
d_drop(dentry);
switched = true;
dentry = d_alloc_parallel(dentry->d_parent,
&dentry->d_name, &wq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
if (unlikely(!d_in_lookup(dentry)))
return finish_no_open(file, dentry);
}
ctx = create_nfs_open_context(dentry, open_flags);
err = PTR_ERR(ctx);
if (IS_ERR(ctx))
@ -1563,14 +1576,23 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
put_nfs_open_context(ctx);
out:
if (unlikely(switched)) {
d_lookup_done(dentry);
dput(dentry);
}
return err;
no_open:
res = nfs_lookup(dir, dentry, lookup_flags);
err = PTR_ERR(res);
if (switched) {
d_lookup_done(dentry);
if (!res)
res = dentry;
else
dput(dentry);
}
if (IS_ERR(res))
goto out;
return PTR_ERR(res);
return finish_no_open(file, res);
}
EXPORT_SYMBOL_GPL(nfs_atomic_open);

View file

@ -43,10 +43,8 @@ struct posix_acl_entry {
};
struct posix_acl {
union {
atomic_t a_refcount;
struct rcu_head a_rcu;
};
atomic_t a_refcount;
struct rcu_head a_rcu;
unsigned int a_count;
struct posix_acl_entry a_entries[0];
};