mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-13 22:14:20 +08:00
a05aea98d4
To help make the move of sysctls out of kernel/sysctl.c not incur a size penalty sysctl has been changed to allow us to not require the sentinel, the final empty element on the sysctl array. Joel Granados has been doing all this work. On the v6.6 kernel we got the major infrastructure changes required to support this. For v6.7 we had all arch/ and drivers/ modified to remove the sentinel. For v6.8-rc1 we get a few more updates for fs/ directory only. The kernel/ directory is left but we'll save that for v6.9-rc1 as those patches are still being reviewed. After that we then can expect also the removal of the no longer needed check for procname == NULL. Let us recap the purpose of this work: - this helps reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array - the extra 64-byte penalty is no longer inncurred now when we move sysctls out from kernel/sysctl.c to their own files Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to see further work by Thomas Weißschuh with the constificatin of the struct ctl_table. Due to Joel Granados's work, and to help bring in new blood, I have suggested for him to become a maintainer and he's accepted. So for v6.9-rc1 I look forward to seeing him sent you a pull request for further sysctl changes. This also removes Iurii Zaikin as a maintainer as he has moved on to other projects and has had no time to help at all. -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEENnNq2KuOejlQLZofziMdCjCSiKcFAmWdWDESHG1jZ3JvZkBr ZXJuZWwub3JnAAoJEM4jHQowkoinjJAP/jTNNoyzWisvrrvmXqR5txFGLOE+wW6x Xv9avuiM+DTHsH/wK8CkXEivwDqYNAZEHU7NEcolS5bJX/ddSRwN9b5aSVlCrUdX Ab4rXmpeSCNFp9zNszWJsDuBKIqjvsKw7qGleGtgZ2qAUHbbH30VROLWCggaee50 wU3icDLdwkasxrcMXy4Sq5dT5wYC4j/QelqBGIkYPT14Arl1im5zqPZ95gmO/s/6 mdicTAmq+hhAUfUBJBXRKtsvxY6CItxe55Q4fjpncLUJLHUw+VPVNoBKFWJlBwlh LO3liKFfakPSkil4/en+/+zuMByd0JBkIzIJa+Kk5kjpbHRhK0RkmU4+Y5G5spWN jjLfiv6RxInNaZ8EWQBMfjE95A7PmYDQ4TOH08+OvzdDIi6B0BB5tBGQpG9BnyXk YsLg1Uo4CwE/vn1/a9w0rhadjUInvmAryhb/uSJYFz/lmApLm2JUpY3/KstwGetb z+HmLstJb24Djkr6pH8DcjhzRBHeWQ5p0b4/6B+v1HqAUuEhdbyw1F2GrDywyF3R h/UOAaKLm1+ffdA246o9TejKiDU96qEzzXMaCzPKyestaRZuiyuYEMDhYbvtsMV5 zIdMJj5HQ+U1KHDv4IN99DEj7+/vjE3f4Sjo+POFpQeQ8/d+fxpFNqXVv449dgnb 6xEkkxsR0ElM =2qBt -----END PGP SIGNATURE----- Merge tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "To help make the move of sysctls out of kernel/sysctl.c not incur a size penalty sysctl has been changed to allow us to not require the sentinel, the final empty element on the sysctl array. Joel Granados has been doing all this work. In the v6.6 kernel we got the major infrastructure changes required to support this. For v6.7 we had all arch/ and drivers/ modified to remove the sentinel. For v6.8-rc1 we get a few more updates for fs/ directory only. The kernel/ directory is left but we'll save that for v6.9-rc1 as those patches are still being reviewed. After that we then can expect also the removal of the no longer needed check for procname == NULL. Let us recap the purpose of this work: - this helps reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array - the extra 64-byte penalty is no longer inncurred now when we move sysctls out from kernel/sysctl.c to their own files Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to see further work by Thomas Weißschuh with the constificatin of the struct ctl_table. Due to Joel Granados's work, and to help bring in new blood, I have suggested for him to become a maintainer and he's accepted. So for v6.9-rc1 I look forward to seeing him sent you a pull request for further sysctl changes. This also removes Iurii Zaikin as a maintainer as he has moved on to other projects and has had no time to help at all" * tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: remove struct ctl_path sysctl: delete unused define SYSCTL_PERM_EMPTY_DIR coda: Remove the now superfluous sentinel elements from ctl_table array sysctl: Remove the now superfluous sentinel elements from ctl_table array fs: Remove the now superfluous sentinel elements from ctl_table array cachefiles: Remove the now superfluous sentinel element from ctl_table array sysclt: Clarify the results of selftest run sysctl: Add a selftest for handling empty dirs sysctl: Fix out of bounds access for empty sysctl registers MAINTAINERS: Add Joel Granados as co-maintainer for proc sysctl MAINTAINERS: remove Iurii Zaikin from proc sysctl
2441 lines
62 KiB
C
2441 lines
62 KiB
C
/*
|
|
* An async IO implementation for Linux
|
|
* Written by Benjamin LaHaise <bcrl@kvack.org>
|
|
*
|
|
* Implements an efficient asynchronous io interface.
|
|
*
|
|
* Copyright 2000, 2001, 2002 Red Hat, Inc. All Rights Reserved.
|
|
* Copyright 2018 Christoph Hellwig.
|
|
*
|
|
* See ../COPYING for licensing terms.
|
|
*/
|
|
#define pr_fmt(fmt) "%s: " fmt, __func__
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/time.h>
|
|
#include <linux/aio_abi.h>
|
|
#include <linux/export.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/refcount.h>
|
|
#include <linux/uio.h>
|
|
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/file.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/aio.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/security.h>
|
|
#include <linux/eventfd.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/migrate.h>
|
|
#include <linux/ramfs.h>
|
|
#include <linux/percpu-refcount.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pseudo_fs.h>
|
|
|
|
#include <linux/uaccess.h>
|
|
#include <linux/nospec.h>
|
|
|
|
#include "internal.h"
|
|
|
|
#define KIOCB_KEY 0
|
|
|
|
#define AIO_RING_MAGIC 0xa10a10a1
|
|
#define AIO_RING_COMPAT_FEATURES 1
|
|
#define AIO_RING_INCOMPAT_FEATURES 0
|
|
struct aio_ring {
|
|
unsigned id; /* kernel internal index number */
|
|
unsigned nr; /* number of io_events */
|
|
unsigned head; /* Written to by userland or under ring_lock
|
|
* mutex by aio_read_events_ring(). */
|
|
unsigned tail;
|
|
|
|
unsigned magic;
|
|
unsigned compat_features;
|
|
unsigned incompat_features;
|
|
unsigned header_length; /* size of aio_ring */
|
|
|
|
|
|
struct io_event io_events[];
|
|
}; /* 128 bytes + ring size */
|
|
|
|
/*
|
|
* Plugging is meant to work with larger batches of IOs. If we don't
|
|
* have more than the below, then don't bother setting up a plug.
|
|
*/
|
|
#define AIO_PLUG_THRESHOLD 2
|
|
|
|
#define AIO_RING_PAGES 8
|
|
|
|
struct kioctx_table {
|
|
struct rcu_head rcu;
|
|
unsigned nr;
|
|
struct kioctx __rcu *table[] __counted_by(nr);
|
|
};
|
|
|
|
struct kioctx_cpu {
|
|
unsigned reqs_available;
|
|
};
|
|
|
|
struct ctx_rq_wait {
|
|
struct completion comp;
|
|
atomic_t count;
|
|
};
|
|
|
|
struct kioctx {
|
|
struct percpu_ref users;
|
|
atomic_t dead;
|
|
|
|
struct percpu_ref reqs;
|
|
|
|
unsigned long user_id;
|
|
|
|
struct __percpu kioctx_cpu *cpu;
|
|
|
|
/*
|
|
* For percpu reqs_available, number of slots we move to/from global
|
|
* counter at a time:
|
|
*/
|
|
unsigned req_batch;
|
|
/*
|
|
* This is what userspace passed to io_setup(), it's not used for
|
|
* anything but counting against the global max_reqs quota.
|
|
*
|
|
* The real limit is nr_events - 1, which will be larger (see
|
|
* aio_setup_ring())
|
|
*/
|
|
unsigned max_reqs;
|
|
|
|
/* Size of ringbuffer, in units of struct io_event */
|
|
unsigned nr_events;
|
|
|
|
unsigned long mmap_base;
|
|
unsigned long mmap_size;
|
|
|
|
struct page **ring_pages;
|
|
long nr_pages;
|
|
|
|
struct rcu_work free_rwork; /* see free_ioctx() */
|
|
|
|
/*
|
|
* signals when all in-flight requests are done
|
|
*/
|
|
struct ctx_rq_wait *rq_wait;
|
|
|
|
struct {
|
|
/*
|
|
* This counts the number of available slots in the ringbuffer,
|
|
* so we avoid overflowing it: it's decremented (if positive)
|
|
* when allocating a kiocb and incremented when the resulting
|
|
* io_event is pulled off the ringbuffer.
|
|
*
|
|
* We batch accesses to it with a percpu version.
|
|
*/
|
|
atomic_t reqs_available;
|
|
} ____cacheline_aligned_in_smp;
|
|
|
|
struct {
|
|
spinlock_t ctx_lock;
|
|
struct list_head active_reqs; /* used for cancellation */
|
|
} ____cacheline_aligned_in_smp;
|
|
|
|
struct {
|
|
struct mutex ring_lock;
|
|
wait_queue_head_t wait;
|
|
} ____cacheline_aligned_in_smp;
|
|
|
|
struct {
|
|
unsigned tail;
|
|
unsigned completed_events;
|
|
spinlock_t completion_lock;
|
|
} ____cacheline_aligned_in_smp;
|
|
|
|
struct page *internal_pages[AIO_RING_PAGES];
|
|
struct file *aio_ring_file;
|
|
|
|
unsigned id;
|
|
};
|
|
|
|
/*
|
|
* First field must be the file pointer in all the
|
|
* iocb unions! See also 'struct kiocb' in <linux/fs.h>
|
|
*/
|
|
struct fsync_iocb {
|
|
struct file *file;
|
|
struct work_struct work;
|
|
bool datasync;
|
|
struct cred *creds;
|
|
};
|
|
|
|
struct poll_iocb {
|
|
struct file *file;
|
|
struct wait_queue_head *head;
|
|
__poll_t events;
|
|
bool cancelled;
|
|
bool work_scheduled;
|
|
bool work_need_resched;
|
|
struct wait_queue_entry wait;
|
|
struct work_struct work;
|
|
};
|
|
|
|
/*
|
|
* NOTE! Each of the iocb union members has the file pointer
|
|
* as the first entry in their struct definition. So you can
|
|
* access the file pointer through any of the sub-structs,
|
|
* or directly as just 'ki_filp' in this struct.
|
|
*/
|
|
struct aio_kiocb {
|
|
union {
|
|
struct file *ki_filp;
|
|
struct kiocb rw;
|
|
struct fsync_iocb fsync;
|
|
struct poll_iocb poll;
|
|
};
|
|
|
|
struct kioctx *ki_ctx;
|
|
kiocb_cancel_fn *ki_cancel;
|
|
|
|
struct io_event ki_res;
|
|
|
|
struct list_head ki_list; /* the aio core uses this
|
|
* for cancellation */
|
|
refcount_t ki_refcnt;
|
|
|
|
/*
|
|
* If the aio_resfd field of the userspace iocb is not zero,
|
|
* this is the underlying eventfd context to deliver events to.
|
|
*/
|
|
struct eventfd_ctx *ki_eventfd;
|
|
};
|
|
|
|
/*------ sysctl variables----*/
|
|
static DEFINE_SPINLOCK(aio_nr_lock);
|
|
static unsigned long aio_nr; /* current system wide number of aio requests */
|
|
static unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
|
|
/*----end sysctl variables---*/
|
|
#ifdef CONFIG_SYSCTL
|
|
static struct ctl_table aio_sysctls[] = {
|
|
{
|
|
.procname = "aio-nr",
|
|
.data = &aio_nr,
|
|
.maxlen = sizeof(aio_nr),
|
|
.mode = 0444,
|
|
.proc_handler = proc_doulongvec_minmax,
|
|
},
|
|
{
|
|
.procname = "aio-max-nr",
|
|
.data = &aio_max_nr,
|
|
.maxlen = sizeof(aio_max_nr),
|
|
.mode = 0644,
|
|
.proc_handler = proc_doulongvec_minmax,
|
|
},
|
|
};
|
|
|
|
static void __init aio_sysctl_init(void)
|
|
{
|
|
register_sysctl_init("fs", aio_sysctls);
|
|
}
|
|
#else
|
|
#define aio_sysctl_init() do { } while (0)
|
|
#endif
|
|
|
|
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 file *file;
|
|
struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
|
|
if (IS_ERR(inode))
|
|
return ERR_CAST(inode);
|
|
|
|
inode->i_mapping->a_ops = &aio_ctx_aops;
|
|
inode->i_mapping->i_private_data = ctx;
|
|
inode->i_size = PAGE_SIZE * nr_pages;
|
|
|
|
file = alloc_file_pseudo(inode, aio_mnt, "[aio]",
|
|
O_RDWR, &aio_ring_fops);
|
|
if (IS_ERR(file))
|
|
iput(inode);
|
|
return file;
|
|
}
|
|
|
|
static int aio_init_fs_context(struct fs_context *fc)
|
|
{
|
|
if (!init_pseudo(fc, AIO_RING_MAGIC))
|
|
return -ENOMEM;
|
|
fc->s_iflags |= SB_I_NOEXEC;
|
|
return 0;
|
|
}
|
|
|
|
/* 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",
|
|
.init_fs_context = aio_init_fs_context,
|
|
.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(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
|
|
kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
|
|
aio_sysctl_init();
|
|
return 0;
|
|
}
|
|
__initcall(aio_setup);
|
|
|
|
static void put_aio_ring_file(struct kioctx *ctx)
|
|
{
|
|
struct file *aio_ring_file = ctx->aio_ring_file;
|
|
struct address_space *i_mapping;
|
|
|
|
if (aio_ring_file) {
|
|
truncate_setsize(file_inode(aio_ring_file), 0);
|
|
|
|
/* Prevent further access to the kioctx from migratepages */
|
|
i_mapping = aio_ring_file->f_mapping;
|
|
spin_lock(&i_mapping->i_private_lock);
|
|
i_mapping->i_private_data = NULL;
|
|
ctx->aio_ring_file = NULL;
|
|
spin_unlock(&i_mapping->i_private_lock);
|
|
|
|
fput(aio_ring_file);
|
|
}
|
|
}
|
|
|
|
static void aio_free_ring(struct kioctx *ctx)
|
|
{
|
|
int i;
|
|
|
|
/* Disconnect the kiotx from the ring file. This prevents future
|
|
* accesses to the kioctx from page migration.
|
|
*/
|
|
put_aio_ring_file(ctx);
|
|
|
|
for (i = 0; i < ctx->nr_pages; i++) {
|
|
struct page *page;
|
|
pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
|
|
page_count(ctx->ring_pages[i]));
|
|
page = ctx->ring_pages[i];
|
|
if (!page)
|
|
continue;
|
|
ctx->ring_pages[i] = NULL;
|
|
put_page(page);
|
|
}
|
|
|
|
if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
|
|
kfree(ctx->ring_pages);
|
|
ctx->ring_pages = NULL;
|
|
}
|
|
}
|
|
|
|
static int aio_ring_mremap(struct vm_area_struct *vma)
|
|
{
|
|
struct file *file = vma->vm_file;
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
struct kioctx_table *table;
|
|
int i, res = -EINVAL;
|
|
|
|
spin_lock(&mm->ioctx_lock);
|
|
rcu_read_lock();
|
|
table = rcu_dereference(mm->ioctx_table);
|
|
if (!table)
|
|
goto out_unlock;
|
|
|
|
for (i = 0; i < table->nr; i++) {
|
|
struct kioctx *ctx;
|
|
|
|
ctx = rcu_dereference(table->table[i]);
|
|
if (ctx && ctx->aio_ring_file == file) {
|
|
if (!atomic_read(&ctx->dead)) {
|
|
ctx->user_id = ctx->mmap_base = vma->vm_start;
|
|
res = 0;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
out_unlock:
|
|
rcu_read_unlock();
|
|
spin_unlock(&mm->ioctx_lock);
|
|
return res;
|
|
}
|
|
|
|
static const struct vm_operations_struct aio_ring_vm_ops = {
|
|
.mremap = aio_ring_mremap,
|
|
#if IS_ENABLED(CONFIG_MMU)
|
|
.fault = filemap_fault,
|
|
.map_pages = filemap_map_pages,
|
|
.page_mkwrite = filemap_page_mkwrite,
|
|
#endif
|
|
};
|
|
|
|
static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
vm_flags_set(vma, VM_DONTEXPAND);
|
|
vma->vm_ops = &aio_ring_vm_ops;
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations aio_ring_fops = {
|
|
.mmap = aio_ring_mmap,
|
|
};
|
|
|
|
#if IS_ENABLED(CONFIG_MIGRATION)
|
|
static int aio_migrate_folio(struct address_space *mapping, struct folio *dst,
|
|
struct folio *src, enum migrate_mode mode)
|
|
{
|
|
struct kioctx *ctx;
|
|
unsigned long flags;
|
|
pgoff_t idx;
|
|
int rc;
|
|
|
|
/*
|
|
* We cannot support the _NO_COPY case here, because copy needs to
|
|
* happen under the ctx->completion_lock. That does not work with the
|
|
* migration workflow of MIGRATE_SYNC_NO_COPY.
|
|
*/
|
|
if (mode == MIGRATE_SYNC_NO_COPY)
|
|
return -EINVAL;
|
|
|
|
rc = 0;
|
|
|
|
/* mapping->i_private_lock here protects against the kioctx teardown. */
|
|
spin_lock(&mapping->i_private_lock);
|
|
ctx = mapping->i_private_data;
|
|
if (!ctx) {
|
|
rc = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* The ring_lock mutex. The prevents aio_read_events() from writing
|
|
* to the ring's head, and prevents page migration from mucking in
|
|
* a partially initialized kiotx.
|
|
*/
|
|
if (!mutex_trylock(&ctx->ring_lock)) {
|
|
rc = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
idx = src->index;
|
|
if (idx < (pgoff_t)ctx->nr_pages) {
|
|
/* Make sure the old folio hasn't already been changed */
|
|
if (ctx->ring_pages[idx] != &src->page)
|
|
rc = -EAGAIN;
|
|
} else
|
|
rc = -EINVAL;
|
|
|
|
if (rc != 0)
|
|
goto out_unlock;
|
|
|
|
/* Writeback must be complete */
|
|
BUG_ON(folio_test_writeback(src));
|
|
folio_get(dst);
|
|
|
|
rc = folio_migrate_mapping(mapping, dst, src, 1);
|
|
if (rc != MIGRATEPAGE_SUCCESS) {
|
|
folio_put(dst);
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* Take completion_lock to prevent other writes to the ring buffer
|
|
* while the old folio is copied to the new. This prevents new
|
|
* events from being lost.
|
|
*/
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
folio_migrate_copy(dst, src);
|
|
BUG_ON(ctx->ring_pages[idx] != &src->page);
|
|
ctx->ring_pages[idx] = &dst->page;
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
/* The old folio is no longer accessible. */
|
|
folio_put(src);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&ctx->ring_lock);
|
|
out:
|
|
spin_unlock(&mapping->i_private_lock);
|
|
return rc;
|
|
}
|
|
#else
|
|
#define aio_migrate_folio NULL
|
|
#endif
|
|
|
|
static const struct address_space_operations aio_ctx_aops = {
|
|
.dirty_folio = noop_dirty_folio,
|
|
.migrate_folio = aio_migrate_folio,
|
|
};
|
|
|
|
static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
|
|
{
|
|
struct aio_ring *ring;
|
|
struct mm_struct *mm = current->mm;
|
|
unsigned long size, unused;
|
|
int nr_pages;
|
|
int i;
|
|
struct file *file;
|
|
|
|
/* Compensate for the ring buffer's head/tail overlap entry */
|
|
nr_events += 2; /* 1 is required, 2 for good luck */
|
|
|
|
size = sizeof(struct aio_ring);
|
|
size += sizeof(struct io_event) * nr_events;
|
|
|
|
nr_pages = PFN_UP(size);
|
|
if (nr_pages < 0)
|
|
return -EINVAL;
|
|
|
|
file = aio_private_file(ctx, nr_pages);
|
|
if (IS_ERR(file)) {
|
|
ctx->aio_ring_file = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ctx->aio_ring_file = file;
|
|
nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
|
|
/ sizeof(struct io_event);
|
|
|
|
ctx->ring_pages = ctx->internal_pages;
|
|
if (nr_pages > AIO_RING_PAGES) {
|
|
ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
|
|
GFP_KERNEL);
|
|
if (!ctx->ring_pages) {
|
|
put_aio_ring_file(ctx);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page;
|
|
page = find_or_create_page(file->f_mapping,
|
|
i, GFP_USER | __GFP_ZERO);
|
|
if (!page)
|
|
break;
|
|
pr_debug("pid(%d) page[%d]->count=%d\n",
|
|
current->pid, i, page_count(page));
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
|
|
ctx->ring_pages[i] = page;
|
|
}
|
|
ctx->nr_pages = i;
|
|
|
|
if (unlikely(i != nr_pages)) {
|
|
aio_free_ring(ctx);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ctx->mmap_size = nr_pages * PAGE_SIZE;
|
|
pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
|
|
|
|
if (mmap_write_lock_killable(mm)) {
|
|
ctx->mmap_size = 0;
|
|
aio_free_ring(ctx);
|
|
return -EINTR;
|
|
}
|
|
|
|
ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size,
|
|
PROT_READ | PROT_WRITE,
|
|
MAP_SHARED, 0, 0, &unused, NULL);
|
|
mmap_write_unlock(mm);
|
|
if (IS_ERR((void *)ctx->mmap_base)) {
|
|
ctx->mmap_size = 0;
|
|
aio_free_ring(ctx);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
|
|
|
|
ctx->user_id = ctx->mmap_base;
|
|
ctx->nr_events = nr_events; /* trusted copy */
|
|
|
|
ring = page_address(ctx->ring_pages[0]);
|
|
ring->nr = nr_events; /* user copy */
|
|
ring->id = ~0U;
|
|
ring->head = ring->tail = 0;
|
|
ring->magic = AIO_RING_MAGIC;
|
|
ring->compat_features = AIO_RING_COMPAT_FEATURES;
|
|
ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
|
|
ring->header_length = sizeof(struct aio_ring);
|
|
flush_dcache_page(ctx->ring_pages[0]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
|
|
#define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
|
|
#define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
|
|
|
|
void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
|
|
{
|
|
struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw);
|
|
struct kioctx *ctx = req->ki_ctx;
|
|
unsigned long flags;
|
|
|
|
if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
|
|
return;
|
|
|
|
spin_lock_irqsave(&ctx->ctx_lock, flags);
|
|
list_add_tail(&req->ki_list, &ctx->active_reqs);
|
|
req->ki_cancel = cancel;
|
|
spin_unlock_irqrestore(&ctx->ctx_lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(kiocb_set_cancel_fn);
|
|
|
|
/*
|
|
* free_ioctx() should be RCU delayed to synchronize against the RCU
|
|
* protected lookup_ioctx() and also needs process context to call
|
|
* aio_free_ring(). Use rcu_work.
|
|
*/
|
|
static void free_ioctx(struct work_struct *work)
|
|
{
|
|
struct kioctx *ctx = container_of(to_rcu_work(work), struct kioctx,
|
|
free_rwork);
|
|
pr_debug("freeing %p\n", ctx);
|
|
|
|
aio_free_ring(ctx);
|
|
free_percpu(ctx->cpu);
|
|
percpu_ref_exit(&ctx->reqs);
|
|
percpu_ref_exit(&ctx->users);
|
|
kmem_cache_free(kioctx_cachep, ctx);
|
|
}
|
|
|
|
static void free_ioctx_reqs(struct percpu_ref *ref)
|
|
{
|
|
struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
|
|
|
|
/* At this point we know that there are no any in-flight requests */
|
|
if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
|
|
complete(&ctx->rq_wait->comp);
|
|
|
|
/* Synchronize against RCU protected table->table[] dereferences */
|
|
INIT_RCU_WORK(&ctx->free_rwork, free_ioctx);
|
|
queue_rcu_work(system_wq, &ctx->free_rwork);
|
|
}
|
|
|
|
/*
|
|
* When this function runs, the kioctx has been removed from the "hash table"
|
|
* and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
|
|
* now it's safe to cancel any that need to be.
|
|
*/
|
|
static void free_ioctx_users(struct percpu_ref *ref)
|
|
{
|
|
struct kioctx *ctx = container_of(ref, struct kioctx, users);
|
|
struct aio_kiocb *req;
|
|
|
|
spin_lock_irq(&ctx->ctx_lock);
|
|
|
|
while (!list_empty(&ctx->active_reqs)) {
|
|
req = list_first_entry(&ctx->active_reqs,
|
|
struct aio_kiocb, ki_list);
|
|
req->ki_cancel(&req->rw);
|
|
list_del_init(&req->ki_list);
|
|
}
|
|
|
|
spin_unlock_irq(&ctx->ctx_lock);
|
|
|
|
percpu_ref_kill(&ctx->reqs);
|
|
percpu_ref_put(&ctx->reqs);
|
|
}
|
|
|
|
static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
|
|
{
|
|
unsigned i, new_nr;
|
|
struct kioctx_table *table, *old;
|
|
struct aio_ring *ring;
|
|
|
|
spin_lock(&mm->ioctx_lock);
|
|
table = rcu_dereference_raw(mm->ioctx_table);
|
|
|
|
while (1) {
|
|
if (table)
|
|
for (i = 0; i < table->nr; i++)
|
|
if (!rcu_access_pointer(table->table[i])) {
|
|
ctx->id = i;
|
|
rcu_assign_pointer(table->table[i], ctx);
|
|
spin_unlock(&mm->ioctx_lock);
|
|
|
|
/* While kioctx setup is in progress,
|
|
* we are protected from page migration
|
|
* changes ring_pages by ->ring_lock.
|
|
*/
|
|
ring = page_address(ctx->ring_pages[0]);
|
|
ring->id = ctx->id;
|
|
return 0;
|
|
}
|
|
|
|
new_nr = (table ? table->nr : 1) * 4;
|
|
spin_unlock(&mm->ioctx_lock);
|
|
|
|
table = kzalloc(struct_size(table, table, new_nr), GFP_KERNEL);
|
|
if (!table)
|
|
return -ENOMEM;
|
|
|
|
table->nr = new_nr;
|
|
|
|
spin_lock(&mm->ioctx_lock);
|
|
old = rcu_dereference_raw(mm->ioctx_table);
|
|
|
|
if (!old) {
|
|
rcu_assign_pointer(mm->ioctx_table, table);
|
|
} else if (table->nr > old->nr) {
|
|
memcpy(table->table, old->table,
|
|
old->nr * sizeof(struct kioctx *));
|
|
|
|
rcu_assign_pointer(mm->ioctx_table, table);
|
|
kfree_rcu(old, rcu);
|
|
} else {
|
|
kfree(table);
|
|
table = old;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void aio_nr_sub(unsigned nr)
|
|
{
|
|
spin_lock(&aio_nr_lock);
|
|
if (WARN_ON(aio_nr - nr > aio_nr))
|
|
aio_nr = 0;
|
|
else
|
|
aio_nr -= nr;
|
|
spin_unlock(&aio_nr_lock);
|
|
}
|
|
|
|
/* ioctx_alloc
|
|
* Allocates and initializes an ioctx. Returns an ERR_PTR if it failed.
|
|
*/
|
|
static struct kioctx *ioctx_alloc(unsigned nr_events)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct kioctx *ctx;
|
|
int err = -ENOMEM;
|
|
|
|
/*
|
|
* Store the original nr_events -- what userspace passed to io_setup(),
|
|
* for counting against the global limit -- before it changes.
|
|
*/
|
|
unsigned int max_reqs = nr_events;
|
|
|
|
/*
|
|
* We keep track of the number of available ringbuffer slots, to prevent
|
|
* overflow (reqs_available), and we also use percpu counters for this.
|
|
*
|
|
* So since up to half the slots might be on other cpu's percpu counters
|
|
* and unavailable, double nr_events so userspace sees what they
|
|
* expected: additionally, we move req_batch slots to/from percpu
|
|
* counters at a time, so make sure that isn't 0:
|
|
*/
|
|
nr_events = max(nr_events, num_possible_cpus() * 4);
|
|
nr_events *= 2;
|
|
|
|
/* Prevent overflows */
|
|
if (nr_events > (0x10000000U / sizeof(struct io_event))) {
|
|
pr_debug("ENOMEM: nr_events too high\n");
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
if (!nr_events || (unsigned long)max_reqs > aio_max_nr)
|
|
return ERR_PTR(-EAGAIN);
|
|
|
|
ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
|
|
if (!ctx)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
ctx->max_reqs = max_reqs;
|
|
|
|
spin_lock_init(&ctx->ctx_lock);
|
|
spin_lock_init(&ctx->completion_lock);
|
|
mutex_init(&ctx->ring_lock);
|
|
/* Protect against page migration throughout kiotx setup by keeping
|
|
* the ring_lock mutex held until setup is complete. */
|
|
mutex_lock(&ctx->ring_lock);
|
|
init_waitqueue_head(&ctx->wait);
|
|
|
|
INIT_LIST_HEAD(&ctx->active_reqs);
|
|
|
|
if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL))
|
|
goto err;
|
|
|
|
if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL))
|
|
goto err;
|
|
|
|
ctx->cpu = alloc_percpu(struct kioctx_cpu);
|
|
if (!ctx->cpu)
|
|
goto err;
|
|
|
|
err = aio_setup_ring(ctx, nr_events);
|
|
if (err < 0)
|
|
goto err;
|
|
|
|
atomic_set(&ctx->reqs_available, ctx->nr_events - 1);
|
|
ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4);
|
|
if (ctx->req_batch < 1)
|
|
ctx->req_batch = 1;
|
|
|
|
/* limit the number of system wide aios */
|
|
spin_lock(&aio_nr_lock);
|
|
if (aio_nr + ctx->max_reqs > aio_max_nr ||
|
|
aio_nr + ctx->max_reqs < aio_nr) {
|
|
spin_unlock(&aio_nr_lock);
|
|
err = -EAGAIN;
|
|
goto err_ctx;
|
|
}
|
|
aio_nr += ctx->max_reqs;
|
|
spin_unlock(&aio_nr_lock);
|
|
|
|
percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */
|
|
percpu_ref_get(&ctx->reqs); /* free_ioctx_users() will drop this */
|
|
|
|
err = ioctx_add_table(ctx, mm);
|
|
if (err)
|
|
goto err_cleanup;
|
|
|
|
/* Release the ring_lock mutex now that all setup is complete. */
|
|
mutex_unlock(&ctx->ring_lock);
|
|
|
|
pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
|
|
ctx, ctx->user_id, mm, ctx->nr_events);
|
|
return ctx;
|
|
|
|
err_cleanup:
|
|
aio_nr_sub(ctx->max_reqs);
|
|
err_ctx:
|
|
atomic_set(&ctx->dead, 1);
|
|
if (ctx->mmap_size)
|
|
vm_munmap(ctx->mmap_base, ctx->mmap_size);
|
|
aio_free_ring(ctx);
|
|
err:
|
|
mutex_unlock(&ctx->ring_lock);
|
|
free_percpu(ctx->cpu);
|
|
percpu_ref_exit(&ctx->reqs);
|
|
percpu_ref_exit(&ctx->users);
|
|
kmem_cache_free(kioctx_cachep, ctx);
|
|
pr_debug("error allocating ioctx %d\n", err);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/* kill_ioctx
|
|
* Cancels all outstanding aio requests on an aio context. Used
|
|
* when the processes owning a context have all exited to encourage
|
|
* the rapid destruction of the kioctx.
|
|
*/
|
|
static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
|
|
struct ctx_rq_wait *wait)
|
|
{
|
|
struct kioctx_table *table;
|
|
|
|
spin_lock(&mm->ioctx_lock);
|
|
if (atomic_xchg(&ctx->dead, 1)) {
|
|
spin_unlock(&mm->ioctx_lock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
table = rcu_dereference_raw(mm->ioctx_table);
|
|
WARN_ON(ctx != rcu_access_pointer(table->table[ctx->id]));
|
|
RCU_INIT_POINTER(table->table[ctx->id], NULL);
|
|
spin_unlock(&mm->ioctx_lock);
|
|
|
|
/* free_ioctx_reqs() will do the necessary RCU synchronization */
|
|
wake_up_all(&ctx->wait);
|
|
|
|
/*
|
|
* It'd be more correct to do this in free_ioctx(), after all
|
|
* the outstanding kiocbs have finished - but by then io_destroy
|
|
* has already returned, so io_setup() could potentially return
|
|
* -EAGAIN with no ioctxs actually in use (as far as userspace
|
|
* could tell).
|
|
*/
|
|
aio_nr_sub(ctx->max_reqs);
|
|
|
|
if (ctx->mmap_size)
|
|
vm_munmap(ctx->mmap_base, ctx->mmap_size);
|
|
|
|
ctx->rq_wait = wait;
|
|
percpu_ref_kill(&ctx->users);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* exit_aio: called when the last user of mm goes away. At this point, there is
|
|
* no way for any new requests to be submited or any of the io_* syscalls to be
|
|
* called on the context.
|
|
*
|
|
* There may be outstanding kiocbs, but free_ioctx() will explicitly wait on
|
|
* them.
|
|
*/
|
|
void exit_aio(struct mm_struct *mm)
|
|
{
|
|
struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
|
|
struct ctx_rq_wait wait;
|
|
int i, skipped;
|
|
|
|
if (!table)
|
|
return;
|
|
|
|
atomic_set(&wait.count, table->nr);
|
|
init_completion(&wait.comp);
|
|
|
|
skipped = 0;
|
|
for (i = 0; i < table->nr; ++i) {
|
|
struct kioctx *ctx =
|
|
rcu_dereference_protected(table->table[i], true);
|
|
|
|
if (!ctx) {
|
|
skipped++;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* We don't need to bother with munmap() here - exit_mmap(mm)
|
|
* is coming and it'll unmap everything. And we simply can't,
|
|
* this is not necessarily our ->mm.
|
|
* Since kill_ioctx() uses non-zero ->mmap_size as indicator
|
|
* that it needs to unmap the area, just set it to 0.
|
|
*/
|
|
ctx->mmap_size = 0;
|
|
kill_ioctx(mm, ctx, &wait);
|
|
}
|
|
|
|
if (!atomic_sub_and_test(skipped, &wait.count)) {
|
|
/* Wait until all IO for the context are done. */
|
|
wait_for_completion(&wait.comp);
|
|
}
|
|
|
|
RCU_INIT_POINTER(mm->ioctx_table, NULL);
|
|
kfree(table);
|
|
}
|
|
|
|
static void put_reqs_available(struct kioctx *ctx, unsigned nr)
|
|
{
|
|
struct kioctx_cpu *kcpu;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
kcpu = this_cpu_ptr(ctx->cpu);
|
|
kcpu->reqs_available += nr;
|
|
|
|
while (kcpu->reqs_available >= ctx->req_batch * 2) {
|
|
kcpu->reqs_available -= ctx->req_batch;
|
|
atomic_add(ctx->req_batch, &ctx->reqs_available);
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static bool __get_reqs_available(struct kioctx *ctx)
|
|
{
|
|
struct kioctx_cpu *kcpu;
|
|
bool ret = false;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
kcpu = this_cpu_ptr(ctx->cpu);
|
|
if (!kcpu->reqs_available) {
|
|
int avail = atomic_read(&ctx->reqs_available);
|
|
|
|
do {
|
|
if (avail < ctx->req_batch)
|
|
goto out;
|
|
} while (!atomic_try_cmpxchg(&ctx->reqs_available,
|
|
&avail, avail - ctx->req_batch));
|
|
|
|
kcpu->reqs_available += ctx->req_batch;
|
|
}
|
|
|
|
ret = true;
|
|
kcpu->reqs_available--;
|
|
out:
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
}
|
|
|
|
/* refill_reqs_available
|
|
* Updates the reqs_available reference counts used for tracking the
|
|
* number of free slots in the completion ring. This can be called
|
|
* from aio_complete() (to optimistically update reqs_available) or
|
|
* from aio_get_req() (the we're out of events case). It must be
|
|
* called holding ctx->completion_lock.
|
|
*/
|
|
static void refill_reqs_available(struct kioctx *ctx, unsigned head,
|
|
unsigned tail)
|
|
{
|
|
unsigned events_in_ring, completed;
|
|
|
|
/* Clamp head since userland can write to it. */
|
|
head %= ctx->nr_events;
|
|
if (head <= tail)
|
|
events_in_ring = tail - head;
|
|
else
|
|
events_in_ring = ctx->nr_events - (head - tail);
|
|
|
|
completed = ctx->completed_events;
|
|
if (events_in_ring < completed)
|
|
completed -= events_in_ring;
|
|
else
|
|
completed = 0;
|
|
|
|
if (!completed)
|
|
return;
|
|
|
|
ctx->completed_events -= completed;
|
|
put_reqs_available(ctx, completed);
|
|
}
|
|
|
|
/* user_refill_reqs_available
|
|
* Called to refill reqs_available when aio_get_req() encounters an
|
|
* out of space in the completion ring.
|
|
*/
|
|
static void user_refill_reqs_available(struct kioctx *ctx)
|
|
{
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
if (ctx->completed_events) {
|
|
struct aio_ring *ring;
|
|
unsigned head;
|
|
|
|
/* Access of ring->head may race with aio_read_events_ring()
|
|
* here, but that's okay since whether we read the old version
|
|
* or the new version, and either will be valid. The important
|
|
* part is that head cannot pass tail since we prevent
|
|
* aio_complete() from updating tail by holding
|
|
* ctx->completion_lock. Even if head is invalid, the check
|
|
* against ctx->completed_events below will make sure we do the
|
|
* safe/right thing.
|
|
*/
|
|
ring = page_address(ctx->ring_pages[0]);
|
|
head = ring->head;
|
|
|
|
refill_reqs_available(ctx, head, ctx->tail);
|
|
}
|
|
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
}
|
|
|
|
static bool get_reqs_available(struct kioctx *ctx)
|
|
{
|
|
if (__get_reqs_available(ctx))
|
|
return true;
|
|
user_refill_reqs_available(ctx);
|
|
return __get_reqs_available(ctx);
|
|
}
|
|
|
|
/* aio_get_req
|
|
* Allocate a slot for an aio request.
|
|
* Returns NULL if no requests are free.
|
|
*
|
|
* The refcount is initialized to 2 - one for the async op completion,
|
|
* one for the synchronous code that does this.
|
|
*/
|
|
static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
|
|
{
|
|
struct aio_kiocb *req;
|
|
|
|
req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
|
|
if (unlikely(!req))
|
|
return NULL;
|
|
|
|
if (unlikely(!get_reqs_available(ctx))) {
|
|
kmem_cache_free(kiocb_cachep, req);
|
|
return NULL;
|
|
}
|
|
|
|
percpu_ref_get(&ctx->reqs);
|
|
req->ki_ctx = ctx;
|
|
INIT_LIST_HEAD(&req->ki_list);
|
|
refcount_set(&req->ki_refcnt, 2);
|
|
req->ki_eventfd = NULL;
|
|
return req;
|
|
}
|
|
|
|
static struct kioctx *lookup_ioctx(unsigned long ctx_id)
|
|
{
|
|
struct aio_ring __user *ring = (void __user *)ctx_id;
|
|
struct mm_struct *mm = current->mm;
|
|
struct kioctx *ctx, *ret = NULL;
|
|
struct kioctx_table *table;
|
|
unsigned id;
|
|
|
|
if (get_user(id, &ring->id))
|
|
return NULL;
|
|
|
|
rcu_read_lock();
|
|
table = rcu_dereference(mm->ioctx_table);
|
|
|
|
if (!table || id >= table->nr)
|
|
goto out;
|
|
|
|
id = array_index_nospec(id, table->nr);
|
|
ctx = rcu_dereference(table->table[id]);
|
|
if (ctx && ctx->user_id == ctx_id) {
|
|
if (percpu_ref_tryget_live(&ctx->users))
|
|
ret = ctx;
|
|
}
|
|
out:
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
static inline void iocb_destroy(struct aio_kiocb *iocb)
|
|
{
|
|
if (iocb->ki_eventfd)
|
|
eventfd_ctx_put(iocb->ki_eventfd);
|
|
if (iocb->ki_filp)
|
|
fput(iocb->ki_filp);
|
|
percpu_ref_put(&iocb->ki_ctx->reqs);
|
|
kmem_cache_free(kiocb_cachep, iocb);
|
|
}
|
|
|
|
struct aio_waiter {
|
|
struct wait_queue_entry w;
|
|
size_t min_nr;
|
|
};
|
|
|
|
/* aio_complete
|
|
* Called when the io request on the given iocb is complete.
|
|
*/
|
|
static void aio_complete(struct aio_kiocb *iocb)
|
|
{
|
|
struct kioctx *ctx = iocb->ki_ctx;
|
|
struct aio_ring *ring;
|
|
struct io_event *ev_page, *event;
|
|
unsigned tail, pos, head, avail;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Add a completion event to the ring buffer. Must be done holding
|
|
* ctx->completion_lock to prevent other code from messing with the tail
|
|
* pointer since we might be called from irq context.
|
|
*/
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
|
|
tail = ctx->tail;
|
|
pos = tail + AIO_EVENTS_OFFSET;
|
|
|
|
if (++tail >= ctx->nr_events)
|
|
tail = 0;
|
|
|
|
ev_page = page_address(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
|
|
event = ev_page + pos % AIO_EVENTS_PER_PAGE;
|
|
|
|
*event = iocb->ki_res;
|
|
|
|
flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
|
|
|
|
pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb,
|
|
(void __user *)(unsigned long)iocb->ki_res.obj,
|
|
iocb->ki_res.data, iocb->ki_res.res, iocb->ki_res.res2);
|
|
|
|
/* after flagging the request as done, we
|
|
* must never even look at it again
|
|
*/
|
|
smp_wmb(); /* make event visible before updating tail */
|
|
|
|
ctx->tail = tail;
|
|
|
|
ring = page_address(ctx->ring_pages[0]);
|
|
head = ring->head;
|
|
ring->tail = tail;
|
|
flush_dcache_page(ctx->ring_pages[0]);
|
|
|
|
ctx->completed_events++;
|
|
if (ctx->completed_events > 1)
|
|
refill_reqs_available(ctx, head, tail);
|
|
|
|
avail = tail > head
|
|
? tail - head
|
|
: tail + ctx->nr_events - head;
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
pr_debug("added to ring %p at [%u]\n", iocb, tail);
|
|
|
|
/*
|
|
* Check if the user asked us to deliver the result through an
|
|
* eventfd. The eventfd_signal() function is safe to be called
|
|
* from IRQ context.
|
|
*/
|
|
if (iocb->ki_eventfd)
|
|
eventfd_signal(iocb->ki_eventfd);
|
|
|
|
/*
|
|
* We have to order our ring_info tail store above and test
|
|
* of the wait list below outside the wait lock. This is
|
|
* like in wake_up_bit() where clearing a bit has to be
|
|
* ordered with the unlocked test.
|
|
*/
|
|
smp_mb();
|
|
|
|
if (waitqueue_active(&ctx->wait)) {
|
|
struct aio_waiter *curr, *next;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->wait.lock, flags);
|
|
list_for_each_entry_safe(curr, next, &ctx->wait.head, w.entry)
|
|
if (avail >= curr->min_nr) {
|
|
list_del_init_careful(&curr->w.entry);
|
|
wake_up_process(curr->w.private);
|
|
}
|
|
spin_unlock_irqrestore(&ctx->wait.lock, flags);
|
|
}
|
|
}
|
|
|
|
static inline void iocb_put(struct aio_kiocb *iocb)
|
|
{
|
|
if (refcount_dec_and_test(&iocb->ki_refcnt)) {
|
|
aio_complete(iocb);
|
|
iocb_destroy(iocb);
|
|
}
|
|
}
|
|
|
|
/* aio_read_events_ring
|
|
* Pull an event off of the ioctx's event ring. Returns the number of
|
|
* events fetched
|
|
*/
|
|
static long aio_read_events_ring(struct kioctx *ctx,
|
|
struct io_event __user *event, long nr)
|
|
{
|
|
struct aio_ring *ring;
|
|
unsigned head, tail, pos;
|
|
long ret = 0;
|
|
int copy_ret;
|
|
|
|
/*
|
|
* The mutex can block and wake us up and that will cause
|
|
* wait_event_interruptible_hrtimeout() to schedule without sleeping
|
|
* and repeat. This should be rare enough that it doesn't cause
|
|
* peformance issues. See the comment in read_events() for more detail.
|
|
*/
|
|
sched_annotate_sleep();
|
|
mutex_lock(&ctx->ring_lock);
|
|
|
|
/* Access to ->ring_pages here is protected by ctx->ring_lock. */
|
|
ring = page_address(ctx->ring_pages[0]);
|
|
head = ring->head;
|
|
tail = ring->tail;
|
|
|
|
/*
|
|
* Ensure that once we've read the current tail pointer, that
|
|
* we also see the events that were stored up to the tail.
|
|
*/
|
|
smp_rmb();
|
|
|
|
pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events);
|
|
|
|
if (head == tail)
|
|
goto out;
|
|
|
|
head %= ctx->nr_events;
|
|
tail %= ctx->nr_events;
|
|
|
|
while (ret < nr) {
|
|
long avail;
|
|
struct io_event *ev;
|
|
struct page *page;
|
|
|
|
avail = (head <= tail ? tail : ctx->nr_events) - head;
|
|
if (head == tail)
|
|
break;
|
|
|
|
pos = head + AIO_EVENTS_OFFSET;
|
|
page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
|
|
pos %= AIO_EVENTS_PER_PAGE;
|
|
|
|
avail = min(avail, nr - ret);
|
|
avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - pos);
|
|
|
|
ev = page_address(page);
|
|
copy_ret = copy_to_user(event + ret, ev + pos,
|
|
sizeof(*ev) * avail);
|
|
|
|
if (unlikely(copy_ret)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
ret += avail;
|
|
head += avail;
|
|
head %= ctx->nr_events;
|
|
}
|
|
|
|
ring = page_address(ctx->ring_pages[0]);
|
|
ring->head = head;
|
|
flush_dcache_page(ctx->ring_pages[0]);
|
|
|
|
pr_debug("%li h%u t%u\n", ret, head, tail);
|
|
out:
|
|
mutex_unlock(&ctx->ring_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
|
|
struct io_event __user *event, long *i)
|
|
{
|
|
long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
|
|
|
|
if (ret > 0)
|
|
*i += ret;
|
|
|
|
if (unlikely(atomic_read(&ctx->dead)))
|
|
ret = -EINVAL;
|
|
|
|
if (!*i)
|
|
*i = ret;
|
|
|
|
return ret < 0 || *i >= min_nr;
|
|
}
|
|
|
|
static long read_events(struct kioctx *ctx, long min_nr, long nr,
|
|
struct io_event __user *event,
|
|
ktime_t until)
|
|
{
|
|
struct hrtimer_sleeper t;
|
|
struct aio_waiter w;
|
|
long ret = 0, ret2 = 0;
|
|
|
|
/*
|
|
* Note that aio_read_events() is being called as the conditional - i.e.
|
|
* we're calling it after prepare_to_wait() has set task state to
|
|
* TASK_INTERRUPTIBLE.
|
|
*
|
|
* But aio_read_events() can block, and if it blocks it's going to flip
|
|
* the task state back to TASK_RUNNING.
|
|
*
|
|
* This should be ok, provided it doesn't flip the state back to
|
|
* TASK_RUNNING and return 0 too much - that causes us to spin. That
|
|
* will only happen if the mutex_lock() call blocks, and we then find
|
|
* the ringbuffer empty. So in practice we should be ok, but it's
|
|
* something to be aware of when touching this code.
|
|
*/
|
|
aio_read_events(ctx, min_nr, nr, event, &ret);
|
|
if (until == 0 || ret < 0 || ret >= min_nr)
|
|
return ret;
|
|
|
|
hrtimer_init_sleeper_on_stack(&t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
if (until != KTIME_MAX) {
|
|
hrtimer_set_expires_range_ns(&t.timer, until, current->timer_slack_ns);
|
|
hrtimer_sleeper_start_expires(&t, HRTIMER_MODE_REL);
|
|
}
|
|
|
|
init_wait(&w.w);
|
|
|
|
while (1) {
|
|
unsigned long nr_got = ret;
|
|
|
|
w.min_nr = min_nr - ret;
|
|
|
|
ret2 = prepare_to_wait_event(&ctx->wait, &w.w, TASK_INTERRUPTIBLE);
|
|
if (!ret2 && !t.task)
|
|
ret2 = -ETIME;
|
|
|
|
if (aio_read_events(ctx, min_nr, nr, event, &ret) || ret2)
|
|
break;
|
|
|
|
if (nr_got == ret)
|
|
schedule();
|
|
}
|
|
|
|
finish_wait(&ctx->wait, &w.w);
|
|
hrtimer_cancel(&t.timer);
|
|
destroy_hrtimer_on_stack(&t.timer);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* sys_io_setup:
|
|
* Create an aio_context capable of receiving at least nr_events.
|
|
* ctxp must not point to an aio_context that already exists, and
|
|
* must be initialized to 0 prior to the call. On successful
|
|
* creation of the aio_context, *ctxp is filled in with the resulting
|
|
* handle. May fail with -EINVAL if *ctxp is not initialized,
|
|
* if the specified nr_events exceeds internal limits. May fail
|
|
* with -EAGAIN if the specified nr_events exceeds the user's limit
|
|
* of available events. May fail with -ENOMEM if insufficient kernel
|
|
* resources are available. May fail with -EFAULT if an invalid
|
|
* pointer is passed for ctxp. Will fail with -ENOSYS if not
|
|
* implemented.
|
|
*/
|
|
SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
|
|
{
|
|
struct kioctx *ioctx = NULL;
|
|
unsigned long ctx;
|
|
long ret;
|
|
|
|
ret = get_user(ctx, ctxp);
|
|
if (unlikely(ret))
|
|
goto out;
|
|
|
|
ret = -EINVAL;
|
|
if (unlikely(ctx || nr_events == 0)) {
|
|
pr_debug("EINVAL: ctx %lu nr_events %u\n",
|
|
ctx, nr_events);
|
|
goto out;
|
|
}
|
|
|
|
ioctx = ioctx_alloc(nr_events);
|
|
ret = PTR_ERR(ioctx);
|
|
if (!IS_ERR(ioctx)) {
|
|
ret = put_user(ioctx->user_id, ctxp);
|
|
if (ret)
|
|
kill_ioctx(current->mm, ioctx, NULL);
|
|
percpu_ref_put(&ioctx->users);
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
|
|
{
|
|
struct kioctx *ioctx = NULL;
|
|
unsigned long ctx;
|
|
long ret;
|
|
|
|
ret = get_user(ctx, ctx32p);
|
|
if (unlikely(ret))
|
|
goto out;
|
|
|
|
ret = -EINVAL;
|
|
if (unlikely(ctx || nr_events == 0)) {
|
|
pr_debug("EINVAL: ctx %lu nr_events %u\n",
|
|
ctx, nr_events);
|
|
goto out;
|
|
}
|
|
|
|
ioctx = ioctx_alloc(nr_events);
|
|
ret = PTR_ERR(ioctx);
|
|
if (!IS_ERR(ioctx)) {
|
|
/* truncating is ok because it's a user address */
|
|
ret = put_user((u32)ioctx->user_id, ctx32p);
|
|
if (ret)
|
|
kill_ioctx(current->mm, ioctx, NULL);
|
|
percpu_ref_put(&ioctx->users);
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
/* sys_io_destroy:
|
|
* Destroy the aio_context specified. May cancel any outstanding
|
|
* AIOs and block on completion. Will fail with -ENOSYS if not
|
|
* implemented. May fail with -EINVAL if the context pointed to
|
|
* is invalid.
|
|
*/
|
|
SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
|
|
{
|
|
struct kioctx *ioctx = lookup_ioctx(ctx);
|
|
if (likely(NULL != ioctx)) {
|
|
struct ctx_rq_wait wait;
|
|
int ret;
|
|
|
|
init_completion(&wait.comp);
|
|
atomic_set(&wait.count, 1);
|
|
|
|
/* Pass requests_done to kill_ioctx() where it can be set
|
|
* in a thread-safe way. If we try to set it here then we have
|
|
* a race condition if two io_destroy() called simultaneously.
|
|
*/
|
|
ret = kill_ioctx(current->mm, ioctx, &wait);
|
|
percpu_ref_put(&ioctx->users);
|
|
|
|
/* Wait until all IO for the context are done. Otherwise kernel
|
|
* keep using user-space buffers even if user thinks the context
|
|
* is destroyed.
|
|
*/
|
|
if (!ret)
|
|
wait_for_completion(&wait.comp);
|
|
|
|
return ret;
|
|
}
|
|
pr_debug("EINVAL: invalid context id\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void aio_remove_iocb(struct aio_kiocb *iocb)
|
|
{
|
|
struct kioctx *ctx = iocb->ki_ctx;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->ctx_lock, flags);
|
|
list_del(&iocb->ki_list);
|
|
spin_unlock_irqrestore(&ctx->ctx_lock, flags);
|
|
}
|
|
|
|
static void aio_complete_rw(struct kiocb *kiocb, long res)
|
|
{
|
|
struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, rw);
|
|
|
|
if (!list_empty_careful(&iocb->ki_list))
|
|
aio_remove_iocb(iocb);
|
|
|
|
if (kiocb->ki_flags & IOCB_WRITE) {
|
|
struct inode *inode = file_inode(kiocb->ki_filp);
|
|
|
|
if (S_ISREG(inode->i_mode))
|
|
kiocb_end_write(kiocb);
|
|
}
|
|
|
|
iocb->ki_res.res = res;
|
|
iocb->ki_res.res2 = 0;
|
|
iocb_put(iocb);
|
|
}
|
|
|
|
static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
|
|
{
|
|
int ret;
|
|
|
|
req->ki_complete = aio_complete_rw;
|
|
req->private = NULL;
|
|
req->ki_pos = iocb->aio_offset;
|
|
req->ki_flags = req->ki_filp->f_iocb_flags;
|
|
if (iocb->aio_flags & IOCB_FLAG_RESFD)
|
|
req->ki_flags |= IOCB_EVENTFD;
|
|
if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
|
|
/*
|
|
* If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then
|
|
* aio_reqprio is interpreted as an I/O scheduling
|
|
* class and priority.
|
|
*/
|
|
ret = ioprio_check_cap(iocb->aio_reqprio);
|
|
if (ret) {
|
|
pr_debug("aio ioprio check cap error: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
req->ki_ioprio = iocb->aio_reqprio;
|
|
} else
|
|
req->ki_ioprio = get_current_ioprio();
|
|
|
|
ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
req->ki_flags &= ~IOCB_HIPRI; /* no one is going to poll for this I/O */
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
|
|
struct iovec **iovec, bool vectored, bool compat,
|
|
struct iov_iter *iter)
|
|
{
|
|
void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
|
|
size_t len = iocb->aio_nbytes;
|
|
|
|
if (!vectored) {
|
|
ssize_t ret = import_ubuf(rw, buf, len, iter);
|
|
*iovec = NULL;
|
|
return ret;
|
|
}
|
|
|
|
return __import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter, compat);
|
|
}
|
|
|
|
static inline void aio_rw_done(struct kiocb *req, ssize_t ret)
|
|
{
|
|
switch (ret) {
|
|
case -EIOCBQUEUED:
|
|
break;
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTART_RESTARTBLOCK:
|
|
/*
|
|
* There's no easy way to restart the syscall since other AIO's
|
|
* may be already running. Just fail this IO with EINTR.
|
|
*/
|
|
ret = -EINTR;
|
|
fallthrough;
|
|
default:
|
|
req->ki_complete(req, ret);
|
|
}
|
|
}
|
|
|
|
static int aio_read(struct kiocb *req, const struct iocb *iocb,
|
|
bool vectored, bool compat)
|
|
{
|
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
|
|
struct iov_iter iter;
|
|
struct file *file;
|
|
int ret;
|
|
|
|
ret = aio_prep_rw(req, iocb);
|
|
if (ret)
|
|
return ret;
|
|
file = req->ki_filp;
|
|
if (unlikely(!(file->f_mode & FMODE_READ)))
|
|
return -EBADF;
|
|
if (unlikely(!file->f_op->read_iter))
|
|
return -EINVAL;
|
|
|
|
ret = aio_setup_rw(ITER_DEST, iocb, &iovec, vectored, compat, &iter);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
|
|
if (!ret)
|
|
aio_rw_done(req, call_read_iter(file, req, &iter));
|
|
kfree(iovec);
|
|
return ret;
|
|
}
|
|
|
|
static int aio_write(struct kiocb *req, const struct iocb *iocb,
|
|
bool vectored, bool compat)
|
|
{
|
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
|
|
struct iov_iter iter;
|
|
struct file *file;
|
|
int ret;
|
|
|
|
ret = aio_prep_rw(req, iocb);
|
|
if (ret)
|
|
return ret;
|
|
file = req->ki_filp;
|
|
|
|
if (unlikely(!(file->f_mode & FMODE_WRITE)))
|
|
return -EBADF;
|
|
if (unlikely(!file->f_op->write_iter))
|
|
return -EINVAL;
|
|
|
|
ret = aio_setup_rw(ITER_SOURCE, iocb, &iovec, vectored, compat, &iter);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
|
|
if (!ret) {
|
|
if (S_ISREG(file_inode(file)->i_mode))
|
|
kiocb_start_write(req);
|
|
req->ki_flags |= IOCB_WRITE;
|
|
aio_rw_done(req, call_write_iter(file, req, &iter));
|
|
}
|
|
kfree(iovec);
|
|
return ret;
|
|
}
|
|
|
|
static void aio_fsync_work(struct work_struct *work)
|
|
{
|
|
struct aio_kiocb *iocb = container_of(work, struct aio_kiocb, fsync.work);
|
|
const struct cred *old_cred = override_creds(iocb->fsync.creds);
|
|
|
|
iocb->ki_res.res = vfs_fsync(iocb->fsync.file, iocb->fsync.datasync);
|
|
revert_creds(old_cred);
|
|
put_cred(iocb->fsync.creds);
|
|
iocb_put(iocb);
|
|
}
|
|
|
|
static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
|
|
bool datasync)
|
|
{
|
|
if (unlikely(iocb->aio_buf || iocb->aio_offset || iocb->aio_nbytes ||
|
|
iocb->aio_rw_flags))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(!req->file->f_op->fsync))
|
|
return -EINVAL;
|
|
|
|
req->creds = prepare_creds();
|
|
if (!req->creds)
|
|
return -ENOMEM;
|
|
|
|
req->datasync = datasync;
|
|
INIT_WORK(&req->work, aio_fsync_work);
|
|
schedule_work(&req->work);
|
|
return 0;
|
|
}
|
|
|
|
static void aio_poll_put_work(struct work_struct *work)
|
|
{
|
|
struct poll_iocb *req = container_of(work, struct poll_iocb, work);
|
|
struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
|
|
|
|
iocb_put(iocb);
|
|
}
|
|
|
|
/*
|
|
* Safely lock the waitqueue which the request is on, synchronizing with the
|
|
* case where the ->poll() provider decides to free its waitqueue early.
|
|
*
|
|
* Returns true on success, meaning that req->head->lock was locked, req->wait
|
|
* is on req->head, and an RCU read lock was taken. Returns false if the
|
|
* request was already removed from its waitqueue (which might no longer exist).
|
|
*/
|
|
static bool poll_iocb_lock_wq(struct poll_iocb *req)
|
|
{
|
|
wait_queue_head_t *head;
|
|
|
|
/*
|
|
* While we hold the waitqueue lock and the waitqueue is nonempty,
|
|
* wake_up_pollfree() will wait for us. However, taking the waitqueue
|
|
* lock in the first place can race with the waitqueue being freed.
|
|
*
|
|
* We solve this as eventpoll does: by taking advantage of the fact that
|
|
* all users of wake_up_pollfree() will RCU-delay the actual free. If
|
|
* we enter rcu_read_lock() and see that the pointer to the queue is
|
|
* non-NULL, we can then lock it without the memory being freed out from
|
|
* under us, then check whether the request is still on the queue.
|
|
*
|
|
* Keep holding rcu_read_lock() as long as we hold the queue lock, in
|
|
* case the caller deletes the entry from the queue, leaving it empty.
|
|
* In that case, only RCU prevents the queue memory from being freed.
|
|
*/
|
|
rcu_read_lock();
|
|
head = smp_load_acquire(&req->head);
|
|
if (head) {
|
|
spin_lock(&head->lock);
|
|
if (!list_empty(&req->wait.entry))
|
|
return true;
|
|
spin_unlock(&head->lock);
|
|
}
|
|
rcu_read_unlock();
|
|
return false;
|
|
}
|
|
|
|
static void poll_iocb_unlock_wq(struct poll_iocb *req)
|
|
{
|
|
spin_unlock(&req->head->lock);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void aio_poll_complete_work(struct work_struct *work)
|
|
{
|
|
struct poll_iocb *req = container_of(work, struct poll_iocb, work);
|
|
struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
|
|
struct poll_table_struct pt = { ._key = req->events };
|
|
struct kioctx *ctx = iocb->ki_ctx;
|
|
__poll_t mask = 0;
|
|
|
|
if (!READ_ONCE(req->cancelled))
|
|
mask = vfs_poll(req->file, &pt) & req->events;
|
|
|
|
/*
|
|
* Note that ->ki_cancel callers also delete iocb from active_reqs after
|
|
* calling ->ki_cancel. We need the ctx_lock roundtrip here to
|
|
* synchronize with them. In the cancellation case the list_del_init
|
|
* itself is not actually needed, but harmless so we keep it in to
|
|
* avoid further branches in the fast path.
|
|
*/
|
|
spin_lock_irq(&ctx->ctx_lock);
|
|
if (poll_iocb_lock_wq(req)) {
|
|
if (!mask && !READ_ONCE(req->cancelled)) {
|
|
/*
|
|
* The request isn't actually ready to be completed yet.
|
|
* Reschedule completion if another wakeup came in.
|
|
*/
|
|
if (req->work_need_resched) {
|
|
schedule_work(&req->work);
|
|
req->work_need_resched = false;
|
|
} else {
|
|
req->work_scheduled = false;
|
|
}
|
|
poll_iocb_unlock_wq(req);
|
|
spin_unlock_irq(&ctx->ctx_lock);
|
|
return;
|
|
}
|
|
list_del_init(&req->wait.entry);
|
|
poll_iocb_unlock_wq(req);
|
|
} /* else, POLLFREE has freed the waitqueue, so we must complete */
|
|
list_del_init(&iocb->ki_list);
|
|
iocb->ki_res.res = mangle_poll(mask);
|
|
spin_unlock_irq(&ctx->ctx_lock);
|
|
|
|
iocb_put(iocb);
|
|
}
|
|
|
|
/* assumes we are called with irqs disabled */
|
|
static int aio_poll_cancel(struct kiocb *iocb)
|
|
{
|
|
struct aio_kiocb *aiocb = container_of(iocb, struct aio_kiocb, rw);
|
|
struct poll_iocb *req = &aiocb->poll;
|
|
|
|
if (poll_iocb_lock_wq(req)) {
|
|
WRITE_ONCE(req->cancelled, true);
|
|
if (!req->work_scheduled) {
|
|
schedule_work(&aiocb->poll.work);
|
|
req->work_scheduled = true;
|
|
}
|
|
poll_iocb_unlock_wq(req);
|
|
} /* else, the request was force-cancelled by POLLFREE already */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
|
|
void *key)
|
|
{
|
|
struct poll_iocb *req = container_of(wait, struct poll_iocb, wait);
|
|
struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
|
|
__poll_t mask = key_to_poll(key);
|
|
unsigned long flags;
|
|
|
|
/* for instances that support it check for an event match first: */
|
|
if (mask && !(mask & req->events))
|
|
return 0;
|
|
|
|
/*
|
|
* Complete the request inline if possible. This requires that three
|
|
* conditions be met:
|
|
* 1. An event mask must have been passed. If a plain wakeup was done
|
|
* instead, then mask == 0 and we have to call vfs_poll() to get
|
|
* the events, so inline completion isn't possible.
|
|
* 2. The completion work must not have already been scheduled.
|
|
* 3. ctx_lock must not be busy. We have to use trylock because we
|
|
* already hold the waitqueue lock, so this inverts the normal
|
|
* locking order. Use irqsave/irqrestore because not all
|
|
* filesystems (e.g. fuse) call this function with IRQs disabled,
|
|
* yet IRQs have to be disabled before ctx_lock is obtained.
|
|
*/
|
|
if (mask && !req->work_scheduled &&
|
|
spin_trylock_irqsave(&iocb->ki_ctx->ctx_lock, flags)) {
|
|
struct kioctx *ctx = iocb->ki_ctx;
|
|
|
|
list_del_init(&req->wait.entry);
|
|
list_del(&iocb->ki_list);
|
|
iocb->ki_res.res = mangle_poll(mask);
|
|
if (iocb->ki_eventfd && !eventfd_signal_allowed()) {
|
|
iocb = NULL;
|
|
INIT_WORK(&req->work, aio_poll_put_work);
|
|
schedule_work(&req->work);
|
|
}
|
|
spin_unlock_irqrestore(&ctx->ctx_lock, flags);
|
|
if (iocb)
|
|
iocb_put(iocb);
|
|
} else {
|
|
/*
|
|
* Schedule the completion work if needed. If it was already
|
|
* scheduled, record that another wakeup came in.
|
|
*
|
|
* Don't remove the request from the waitqueue here, as it might
|
|
* not actually be complete yet (we won't know until vfs_poll()
|
|
* is called), and we must not miss any wakeups. POLLFREE is an
|
|
* exception to this; see below.
|
|
*/
|
|
if (req->work_scheduled) {
|
|
req->work_need_resched = true;
|
|
} else {
|
|
schedule_work(&req->work);
|
|
req->work_scheduled = true;
|
|
}
|
|
|
|
/*
|
|
* If the waitqueue is being freed early but we can't complete
|
|
* the request inline, we have to tear down the request as best
|
|
* we can. That means immediately removing the request from its
|
|
* waitqueue and preventing all further accesses to the
|
|
* waitqueue via the request. We also need to schedule the
|
|
* completion work (done above). Also mark the request as
|
|
* cancelled, to potentially skip an unneeded call to ->poll().
|
|
*/
|
|
if (mask & POLLFREE) {
|
|
WRITE_ONCE(req->cancelled, true);
|
|
list_del_init(&req->wait.entry);
|
|
|
|
/*
|
|
* Careful: this *must* be the last step, since as soon
|
|
* as req->head is NULL'ed out, the request can be
|
|
* completed and freed, since aio_poll_complete_work()
|
|
* will no longer need to take the waitqueue lock.
|
|
*/
|
|
smp_store_release(&req->head, NULL);
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
struct aio_poll_table {
|
|
struct poll_table_struct pt;
|
|
struct aio_kiocb *iocb;
|
|
bool queued;
|
|
int error;
|
|
};
|
|
|
|
static void
|
|
aio_poll_queue_proc(struct file *file, struct wait_queue_head *head,
|
|
struct poll_table_struct *p)
|
|
{
|
|
struct aio_poll_table *pt = container_of(p, struct aio_poll_table, pt);
|
|
|
|
/* multiple wait queues per file are not supported */
|
|
if (unlikely(pt->queued)) {
|
|
pt->error = -EINVAL;
|
|
return;
|
|
}
|
|
|
|
pt->queued = true;
|
|
pt->error = 0;
|
|
pt->iocb->poll.head = head;
|
|
add_wait_queue(head, &pt->iocb->poll.wait);
|
|
}
|
|
|
|
static int aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)
|
|
{
|
|
struct kioctx *ctx = aiocb->ki_ctx;
|
|
struct poll_iocb *req = &aiocb->poll;
|
|
struct aio_poll_table apt;
|
|
bool cancel = false;
|
|
__poll_t mask;
|
|
|
|
/* reject any unknown events outside the normal event mask. */
|
|
if ((u16)iocb->aio_buf != iocb->aio_buf)
|
|
return -EINVAL;
|
|
/* reject fields that are not defined for poll */
|
|
if (iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags)
|
|
return -EINVAL;
|
|
|
|
INIT_WORK(&req->work, aio_poll_complete_work);
|
|
req->events = demangle_poll(iocb->aio_buf) | EPOLLERR | EPOLLHUP;
|
|
|
|
req->head = NULL;
|
|
req->cancelled = false;
|
|
req->work_scheduled = false;
|
|
req->work_need_resched = false;
|
|
|
|
apt.pt._qproc = aio_poll_queue_proc;
|
|
apt.pt._key = req->events;
|
|
apt.iocb = aiocb;
|
|
apt.queued = false;
|
|
apt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */
|
|
|
|
/* initialized the list so that we can do list_empty checks */
|
|
INIT_LIST_HEAD(&req->wait.entry);
|
|
init_waitqueue_func_entry(&req->wait, aio_poll_wake);
|
|
|
|
mask = vfs_poll(req->file, &apt.pt) & req->events;
|
|
spin_lock_irq(&ctx->ctx_lock);
|
|
if (likely(apt.queued)) {
|
|
bool on_queue = poll_iocb_lock_wq(req);
|
|
|
|
if (!on_queue || req->work_scheduled) {
|
|
/*
|
|
* aio_poll_wake() already either scheduled the async
|
|
* completion work, or completed the request inline.
|
|
*/
|
|
if (apt.error) /* unsupported case: multiple queues */
|
|
cancel = true;
|
|
apt.error = 0;
|
|
mask = 0;
|
|
}
|
|
if (mask || apt.error) {
|
|
/* Steal to complete synchronously. */
|
|
list_del_init(&req->wait.entry);
|
|
} else if (cancel) {
|
|
/* Cancel if possible (may be too late though). */
|
|
WRITE_ONCE(req->cancelled, true);
|
|
} else if (on_queue) {
|
|
/*
|
|
* Actually waiting for an event, so add the request to
|
|
* active_reqs so that it can be cancelled if needed.
|
|
*/
|
|
list_add_tail(&aiocb->ki_list, &ctx->active_reqs);
|
|
aiocb->ki_cancel = aio_poll_cancel;
|
|
}
|
|
if (on_queue)
|
|
poll_iocb_unlock_wq(req);
|
|
}
|
|
if (mask) { /* no async, we'd stolen it */
|
|
aiocb->ki_res.res = mangle_poll(mask);
|
|
apt.error = 0;
|
|
}
|
|
spin_unlock_irq(&ctx->ctx_lock);
|
|
if (mask)
|
|
iocb_put(aiocb);
|
|
return apt.error;
|
|
}
|
|
|
|
static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
|
|
struct iocb __user *user_iocb, struct aio_kiocb *req,
|
|
bool compat)
|
|
{
|
|
req->ki_filp = fget(iocb->aio_fildes);
|
|
if (unlikely(!req->ki_filp))
|
|
return -EBADF;
|
|
|
|
if (iocb->aio_flags & IOCB_FLAG_RESFD) {
|
|
struct eventfd_ctx *eventfd;
|
|
/*
|
|
* If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
|
|
* instance of the file* now. The file descriptor must be
|
|
* an eventfd() fd, and will be signaled for each completed
|
|
* event using the eventfd_signal() function.
|
|
*/
|
|
eventfd = eventfd_ctx_fdget(iocb->aio_resfd);
|
|
if (IS_ERR(eventfd))
|
|
return PTR_ERR(eventfd);
|
|
|
|
req->ki_eventfd = eventfd;
|
|
}
|
|
|
|
if (unlikely(put_user(KIOCB_KEY, &user_iocb->aio_key))) {
|
|
pr_debug("EFAULT: aio_key\n");
|
|
return -EFAULT;
|
|
}
|
|
|
|
req->ki_res.obj = (u64)(unsigned long)user_iocb;
|
|
req->ki_res.data = iocb->aio_data;
|
|
req->ki_res.res = 0;
|
|
req->ki_res.res2 = 0;
|
|
|
|
switch (iocb->aio_lio_opcode) {
|
|
case IOCB_CMD_PREAD:
|
|
return aio_read(&req->rw, iocb, false, compat);
|
|
case IOCB_CMD_PWRITE:
|
|
return aio_write(&req->rw, iocb, false, compat);
|
|
case IOCB_CMD_PREADV:
|
|
return aio_read(&req->rw, iocb, true, compat);
|
|
case IOCB_CMD_PWRITEV:
|
|
return aio_write(&req->rw, iocb, true, compat);
|
|
case IOCB_CMD_FSYNC:
|
|
return aio_fsync(&req->fsync, iocb, false);
|
|
case IOCB_CMD_FDSYNC:
|
|
return aio_fsync(&req->fsync, iocb, true);
|
|
case IOCB_CMD_POLL:
|
|
return aio_poll(req, iocb);
|
|
default:
|
|
pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
|
|
bool compat)
|
|
{
|
|
struct aio_kiocb *req;
|
|
struct iocb iocb;
|
|
int err;
|
|
|
|
if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb))))
|
|
return -EFAULT;
|
|
|
|
/* enforce forwards compatibility on users */
|
|
if (unlikely(iocb.aio_reserved2)) {
|
|
pr_debug("EINVAL: reserve field set\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* prevent overflows */
|
|
if (unlikely(
|
|
(iocb.aio_buf != (unsigned long)iocb.aio_buf) ||
|
|
(iocb.aio_nbytes != (size_t)iocb.aio_nbytes) ||
|
|
((ssize_t)iocb.aio_nbytes < 0)
|
|
)) {
|
|
pr_debug("EINVAL: overflow check\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
req = aio_get_req(ctx);
|
|
if (unlikely(!req))
|
|
return -EAGAIN;
|
|
|
|
err = __io_submit_one(ctx, &iocb, user_iocb, req, compat);
|
|
|
|
/* Done with the synchronous reference */
|
|
iocb_put(req);
|
|
|
|
/*
|
|
* If err is 0, we'd either done aio_complete() ourselves or have
|
|
* arranged for that to be done asynchronously. Anything non-zero
|
|
* means that we need to destroy req ourselves.
|
|
*/
|
|
if (unlikely(err)) {
|
|
iocb_destroy(req);
|
|
put_reqs_available(ctx, 1);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/* sys_io_submit:
|
|
* Queue the nr iocbs pointed to by iocbpp for processing. Returns
|
|
* the number of iocbs queued. May return -EINVAL if the aio_context
|
|
* specified by ctx_id is invalid, if nr is < 0, if the iocb at
|
|
* *iocbpp[0] is not properly initialized, if the operation specified
|
|
* is invalid for the file descriptor in the iocb. May fail with
|
|
* -EFAULT if any of the data structures point to invalid data. May
|
|
* fail with -EBADF if the file descriptor specified in the first
|
|
* iocb is invalid. May fail with -EAGAIN if insufficient resources
|
|
* are available to queue any iocbs. Will return 0 if nr is 0. Will
|
|
* fail with -ENOSYS if not implemented.
|
|
*/
|
|
SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
|
|
struct iocb __user * __user *, iocbpp)
|
|
{
|
|
struct kioctx *ctx;
|
|
long ret = 0;
|
|
int i = 0;
|
|
struct blk_plug plug;
|
|
|
|
if (unlikely(nr < 0))
|
|
return -EINVAL;
|
|
|
|
ctx = lookup_ioctx(ctx_id);
|
|
if (unlikely(!ctx)) {
|
|
pr_debug("EINVAL: invalid context id\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nr > ctx->nr_events)
|
|
nr = ctx->nr_events;
|
|
|
|
if (nr > AIO_PLUG_THRESHOLD)
|
|
blk_start_plug(&plug);
|
|
for (i = 0; i < nr; i++) {
|
|
struct iocb __user *user_iocb;
|
|
|
|
if (unlikely(get_user(user_iocb, iocbpp + i))) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
ret = io_submit_one(ctx, user_iocb, false);
|
|
if (ret)
|
|
break;
|
|
}
|
|
if (nr > AIO_PLUG_THRESHOLD)
|
|
blk_finish_plug(&plug);
|
|
|
|
percpu_ref_put(&ctx->users);
|
|
return i ? i : ret;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
|
|
int, nr, compat_uptr_t __user *, iocbpp)
|
|
{
|
|
struct kioctx *ctx;
|
|
long ret = 0;
|
|
int i = 0;
|
|
struct blk_plug plug;
|
|
|
|
if (unlikely(nr < 0))
|
|
return -EINVAL;
|
|
|
|
ctx = lookup_ioctx(ctx_id);
|
|
if (unlikely(!ctx)) {
|
|
pr_debug("EINVAL: invalid context id\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nr > ctx->nr_events)
|
|
nr = ctx->nr_events;
|
|
|
|
if (nr > AIO_PLUG_THRESHOLD)
|
|
blk_start_plug(&plug);
|
|
for (i = 0; i < nr; i++) {
|
|
compat_uptr_t user_iocb;
|
|
|
|
if (unlikely(get_user(user_iocb, iocbpp + i))) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
ret = io_submit_one(ctx, compat_ptr(user_iocb), true);
|
|
if (ret)
|
|
break;
|
|
}
|
|
if (nr > AIO_PLUG_THRESHOLD)
|
|
blk_finish_plug(&plug);
|
|
|
|
percpu_ref_put(&ctx->users);
|
|
return i ? i : ret;
|
|
}
|
|
#endif
|
|
|
|
/* sys_io_cancel:
|
|
* Attempts to cancel an iocb previously passed to io_submit. If
|
|
* the operation is successfully cancelled, the resulting event is
|
|
* copied into the memory pointed to by result without being placed
|
|
* into the completion queue and 0 is returned. May fail with
|
|
* -EFAULT if any of the data structures pointed to are invalid.
|
|
* May fail with -EINVAL if aio_context specified by ctx_id is
|
|
* invalid. May fail with -EAGAIN if the iocb specified was not
|
|
* cancelled. Will fail with -ENOSYS if not implemented.
|
|
*/
|
|
SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
|
|
struct io_event __user *, result)
|
|
{
|
|
struct kioctx *ctx;
|
|
struct aio_kiocb *kiocb;
|
|
int ret = -EINVAL;
|
|
u32 key;
|
|
u64 obj = (u64)(unsigned long)iocb;
|
|
|
|
if (unlikely(get_user(key, &iocb->aio_key)))
|
|
return -EFAULT;
|
|
if (unlikely(key != KIOCB_KEY))
|
|
return -EINVAL;
|
|
|
|
ctx = lookup_ioctx(ctx_id);
|
|
if (unlikely(!ctx))
|
|
return -EINVAL;
|
|
|
|
spin_lock_irq(&ctx->ctx_lock);
|
|
/* TODO: use a hash or array, this sucks. */
|
|
list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) {
|
|
if (kiocb->ki_res.obj == obj) {
|
|
ret = kiocb->ki_cancel(&kiocb->rw);
|
|
list_del_init(&kiocb->ki_list);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock_irq(&ctx->ctx_lock);
|
|
|
|
if (!ret) {
|
|
/*
|
|
* The result argument is no longer used - the io_event is
|
|
* always delivered via the ring buffer. -EINPROGRESS indicates
|
|
* cancellation is progress:
|
|
*/
|
|
ret = -EINPROGRESS;
|
|
}
|
|
|
|
percpu_ref_put(&ctx->users);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static long do_io_getevents(aio_context_t ctx_id,
|
|
long min_nr,
|
|
long nr,
|
|
struct io_event __user *events,
|
|
struct timespec64 *ts)
|
|
{
|
|
ktime_t until = ts ? timespec64_to_ktime(*ts) : KTIME_MAX;
|
|
struct kioctx *ioctx = lookup_ioctx(ctx_id);
|
|
long ret = -EINVAL;
|
|
|
|
if (likely(ioctx)) {
|
|
if (likely(min_nr <= nr && min_nr >= 0))
|
|
ret = read_events(ioctx, min_nr, nr, events, until);
|
|
percpu_ref_put(&ioctx->users);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* io_getevents:
|
|
* Attempts to read at least min_nr events and up to nr events from
|
|
* the completion queue for the aio_context specified by ctx_id. If
|
|
* it succeeds, the number of read events is returned. May fail with
|
|
* -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is
|
|
* out of range, if timeout is out of range. May fail with -EFAULT
|
|
* if any of the memory specified is invalid. May return 0 or
|
|
* < min_nr if the timeout specified by timeout has elapsed
|
|
* before sufficient events are available, where timeout == NULL
|
|
* specifies an infinite timeout. Note that the timeout pointed to by
|
|
* timeout is relative. Will fail with -ENOSYS if not implemented.
|
|
*/
|
|
#ifdef CONFIG_64BIT
|
|
|
|
SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
|
|
long, min_nr,
|
|
long, nr,
|
|
struct io_event __user *, events,
|
|
struct __kernel_timespec __user *, timeout)
|
|
{
|
|
struct timespec64 ts;
|
|
int ret;
|
|
|
|
if (timeout && unlikely(get_timespec64(&ts, timeout)))
|
|
return -EFAULT;
|
|
|
|
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
|
|
if (!ret && signal_pending(current))
|
|
ret = -EINTR;
|
|
return ret;
|
|
}
|
|
|
|
#endif
|
|
|
|
struct __aio_sigset {
|
|
const sigset_t __user *sigmask;
|
|
size_t sigsetsize;
|
|
};
|
|
|
|
SYSCALL_DEFINE6(io_pgetevents,
|
|
aio_context_t, ctx_id,
|
|
long, min_nr,
|
|
long, nr,
|
|
struct io_event __user *, events,
|
|
struct __kernel_timespec __user *, timeout,
|
|
const struct __aio_sigset __user *, usig)
|
|
{
|
|
struct __aio_sigset ksig = { NULL, };
|
|
struct timespec64 ts;
|
|
bool interrupted;
|
|
int ret;
|
|
|
|
if (timeout && unlikely(get_timespec64(&ts, timeout)))
|
|
return -EFAULT;
|
|
|
|
if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
|
|
return -EFAULT;
|
|
|
|
ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
|
|
|
|
interrupted = signal_pending(current);
|
|
restore_saved_sigmask_unless(interrupted);
|
|
if (interrupted && !ret)
|
|
ret = -ERESTARTNOHAND;
|
|
|
|
return ret;
|
|
}
|
|
|
|
#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
|
|
|
|
SYSCALL_DEFINE6(io_pgetevents_time32,
|
|
aio_context_t, ctx_id,
|
|
long, min_nr,
|
|
long, nr,
|
|
struct io_event __user *, events,
|
|
struct old_timespec32 __user *, timeout,
|
|
const struct __aio_sigset __user *, usig)
|
|
{
|
|
struct __aio_sigset ksig = { NULL, };
|
|
struct timespec64 ts;
|
|
bool interrupted;
|
|
int ret;
|
|
|
|
if (timeout && unlikely(get_old_timespec32(&ts, timeout)))
|
|
return -EFAULT;
|
|
|
|
if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
|
|
return -EFAULT;
|
|
|
|
|
|
ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
|
|
|
|
interrupted = signal_pending(current);
|
|
restore_saved_sigmask_unless(interrupted);
|
|
if (interrupted && !ret)
|
|
ret = -ERESTARTNOHAND;
|
|
|
|
return ret;
|
|
}
|
|
|
|
#endif
|
|
|
|
#if defined(CONFIG_COMPAT_32BIT_TIME)
|
|
|
|
SYSCALL_DEFINE5(io_getevents_time32, __u32, ctx_id,
|
|
__s32, min_nr,
|
|
__s32, nr,
|
|
struct io_event __user *, events,
|
|
struct old_timespec32 __user *, timeout)
|
|
{
|
|
struct timespec64 t;
|
|
int ret;
|
|
|
|
if (timeout && get_old_timespec32(&t, timeout))
|
|
return -EFAULT;
|
|
|
|
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
|
|
if (!ret && signal_pending(current))
|
|
ret = -EINTR;
|
|
return ret;
|
|
}
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
struct __compat_aio_sigset {
|
|
compat_uptr_t sigmask;
|
|
compat_size_t sigsetsize;
|
|
};
|
|
|
|
#if defined(CONFIG_COMPAT_32BIT_TIME)
|
|
|
|
COMPAT_SYSCALL_DEFINE6(io_pgetevents,
|
|
compat_aio_context_t, ctx_id,
|
|
compat_long_t, min_nr,
|
|
compat_long_t, nr,
|
|
struct io_event __user *, events,
|
|
struct old_timespec32 __user *, timeout,
|
|
const struct __compat_aio_sigset __user *, usig)
|
|
{
|
|
struct __compat_aio_sigset ksig = { 0, };
|
|
struct timespec64 t;
|
|
bool interrupted;
|
|
int ret;
|
|
|
|
if (timeout && get_old_timespec32(&t, timeout))
|
|
return -EFAULT;
|
|
|
|
if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
|
|
return -EFAULT;
|
|
|
|
ret = set_compat_user_sigmask(compat_ptr(ksig.sigmask), ksig.sigsetsize);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
|
|
|
|
interrupted = signal_pending(current);
|
|
restore_saved_sigmask_unless(interrupted);
|
|
if (interrupted && !ret)
|
|
ret = -ERESTARTNOHAND;
|
|
|
|
return ret;
|
|
}
|
|
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64,
|
|
compat_aio_context_t, ctx_id,
|
|
compat_long_t, min_nr,
|
|
compat_long_t, nr,
|
|
struct io_event __user *, events,
|
|
struct __kernel_timespec __user *, timeout,
|
|
const struct __compat_aio_sigset __user *, usig)
|
|
{
|
|
struct __compat_aio_sigset ksig = { 0, };
|
|
struct timespec64 t;
|
|
bool interrupted;
|
|
int ret;
|
|
|
|
if (timeout && get_timespec64(&t, timeout))
|
|
return -EFAULT;
|
|
|
|
if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
|
|
return -EFAULT;
|
|
|
|
ret = set_compat_user_sigmask(compat_ptr(ksig.sigmask), ksig.sigsetsize);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
|
|
|
|
interrupted = signal_pending(current);
|
|
restore_saved_sigmask_unless(interrupted);
|
|
if (interrupted && !ret)
|
|
ret = -ERESTARTNOHAND;
|
|
|
|
return ret;
|
|
}
|
|
#endif
|