Commit d93aa9d8 authored by Al Viro's avatar Al Viro

new wrapper: alloc_file_pseudo()

takes inode, vfsmount, name, O_... flags and file_operations and
either returns a new struct file (in which case inode reference we
held is consumed) or returns ERR_PTR(), in which case no refcounts
are altered.

converted aio_private_file() and sock_alloc_file() to it
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent dbae8f2c
......@@ -215,9 +215,7 @@ static const struct address_space_operations aio_ctx_aops;
static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
{
struct qstr this = QSTR_INIT("[aio]", 5);
struct file *file;
struct path path;
struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
if (IS_ERR(inode))
return ERR_CAST(inode);
......@@ -226,27 +224,17 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
inode->i_mapping->private_data = ctx;
inode->i_size = PAGE_SIZE * nr_pages;
path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
if (!path.dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
path.mnt = mntget(aio_mnt);
d_instantiate(path.dentry, inode);
file = alloc_file(&path, O_RDWR, &aio_ring_fops);
file = alloc_file_pseudo(inode, aio_mnt, "[aio]",
O_RDWR, &aio_ring_fops);
if (IS_ERR(file))
path_put(&path);
iput(inode);
return file;
}
static struct dentry *aio_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
static const struct dentry_operations ops = {
.d_dname = simple_dname,
};
struct dentry *root = mount_pseudo(fs_type, "aio:", NULL, &ops,
struct dentry *root = mount_pseudo(fs_type, "aio:", NULL, NULL,
AIO_RING_MAGIC);
if (!IS_ERR(root))
......
......@@ -184,6 +184,33 @@ struct file *alloc_file(const struct path *path, int flags,
}
EXPORT_SYMBOL(alloc_file);
struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
const char *name, int flags,
const struct file_operations *fops)
{
static const struct dentry_operations anon_ops = {
.d_dname = simple_dname
};
struct qstr this = QSTR_INIT(name, strlen(name));
struct path path;
struct file *file;
path.dentry = d_alloc_pseudo(mnt->mnt_sb, &this);
if (!path.dentry)
return ERR_PTR(-ENOMEM);
if (!mnt->mnt_sb->s_d_op)
d_set_d_op(path.dentry, &anon_ops);
path.mnt = mntget(mnt);
d_instantiate(path.dentry, inode);
file = alloc_file(&path, flags, fops);
if (IS_ERR(file)) {
ihold(inode);
path_put(&path);
}
return file;
}
EXPORT_SYMBOL(alloc_file_pseudo);
/* the real guts of fput() - releasing the last reference to file
*/
static void __fput(struct file *file)
......
......@@ -17,9 +17,12 @@ extern void fput(struct file *);
struct file_operations;
struct vfsmount;
struct dentry;
struct inode;
struct path;
extern struct file *alloc_file(const struct path *, int flags,
const struct file_operations *fop);
extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
const char *, int flags, const struct file_operations *);
static inline void fput_light(struct file *file, int fput_needed)
{
......
......@@ -391,33 +391,15 @@ static struct file_system_type sock_fs_type = {
struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
{
struct qstr name = { .name = "" };
struct path path;
struct file *file;
if (dname) {
name.name = dname;
name.len = strlen(name.name);
} else if (sock->sk) {
name.name = sock->sk->sk_prot_creator->name;
name.len = strlen(name.name);
}
path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
if (unlikely(!path.dentry)) {
sock_release(sock);
return ERR_PTR(-ENOMEM);
}
path.mnt = mntget(sock_mnt);
d_instantiate(path.dentry, SOCK_INODE(sock));
if (!dname)
dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
file = alloc_file(&path, O_RDWR | (flags & O_NONBLOCK),
&socket_file_ops);
file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
O_RDWR | (flags & O_NONBLOCK),
&socket_file_ops);
if (IS_ERR(file)) {
/* drop dentry, keep inode for a bit */
ihold(d_inode(path.dentry));
path_put(&path);
/* ... and now kill it properly */
sock_release(sock);
return file;
}
......
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