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Commit 71ad7490 authored by Benjamin LaHaise's avatar Benjamin LaHaise Committed by Al Viro
Browse files

rework aio migrate pages to use aio fs 



Don't abuse anon_inodes.c to host private files needed by aio;
we can bloody well declare a mini-fs of our own instead of
patching up what anon_inodes can create for us.

Tested-by: default avatarBenjamin LaHaise <bcrl@kvack.org>
Acked-by: default avatarBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 6987843f

fs/aio.c

+57 −6
Original line number Diff line number Diff line
@@ -36,10 +36,10 @@ 
#include <linux/eventfd.h>

#include <linux/blkdev.h>

#include <linux/compat.h>

#include <linux/anon_inodes.h>

#include <linux/migrate.h>

#include <linux/ramfs.h>

#include <linux/percpu-refcount.h>

#include <linux/mount.h>



#include <asm/kmap_types.h>

#include <asm/uaccess.h>
@@ -152,12 +152,67 @@ unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio request 
static struct kmem_cache	*kiocb_cachep;

static struct kmem_cache	*kioctx_cachep;



static struct vfsmount *aio_mnt;



static const struct file_operations aio_ring_fops;

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 (!inode)

		return ERR_PTR(-ENOMEM);



	inode->i_mapping->a_ops = &aio_ctx_aops;

	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, FMODE_READ | FMODE_WRITE, &aio_ring_fops);

	if (IS_ERR(file)) {

		path_put(&path);

		return file;

	}



	file->f_flags = O_RDWR;

	file->private_data = ctx;

	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,

	};

	return mount_pseudo(fs_type, "aio:", NULL, &ops, 0xa10a10a1);

}



/* aio_setup

 *	Creates the slab caches used by the aio routines, panic on

 *	failure as this is done early during the boot sequence.

 */

static int __init aio_setup(void)

{

	static struct file_system_type aio_fs = {

		.name		= "aio",

		.mount		= aio_mount,

		.kill_sb	= kill_anon_super,

	};

	aio_mnt = kern_mount(&aio_fs);

	if (IS_ERR(aio_mnt))

		panic("Failed to create aio fs mount.");



	kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);

	kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
@@ -283,16 +338,12 @@ static int aio_setup_ring(struct kioctx *ctx) 
	if (nr_pages < 0)

		return -EINVAL;



	file = anon_inode_getfile_private("[aio]", &aio_ring_fops, ctx, O_RDWR);

	file = aio_private_file(ctx, nr_pages);

	if (IS_ERR(file)) {

		ctx->aio_ring_file = NULL;

		return -EAGAIN;

	}



	file->f_inode->i_mapping->a_ops = &aio_ctx_aops;

	file->f_inode->i_mapping->private_data = ctx;

	file->f_inode->i_size = PAGE_SIZE * (loff_t)nr_pages;



	for (i = 0; i < nr_pages; i++) {

		struct page *page;

		page = find_or_create_page(file->f_inode->i_mapping,