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Commit d93aa9d8 authored by Al Viro's avatar Al Viro
Browse files

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

fs/aio.c

+4 −16
Original line number Diff line number Diff line
@@ -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))

fs/file_table.c

+27 −0
Original line number Diff line number Diff line
@@ -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)

include/linux/file.h

+3 −0
Original line number Diff line number Diff line
@@ -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)

{

net/socket.c

+5 −23
Original line number Diff line number Diff line
@@ -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),

	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;

	}