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: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Benjamin LaHaise 2013-09-17 10:18:25 -04:00 коммит произвёл Al Viro
Родитель 6987843ff7
Коммит 71ad7490c1
1 изменённых файлов: 57 добавлений и 6 удалений

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@ -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,