aio: percpu ioctx refcount
This just converts the ioctx refcount to the new generic dynamic percpu refcount code. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
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parent
e1bdd5f27a
commit
723be6e39d
66
fs/aio.c
66
fs/aio.c
@ -39,6 +39,7 @@
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#include <linux/anon_inodes.h>
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#include <linux/migrate.h>
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#include <linux/ramfs.h>
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#include <linux/percpu-refcount.h>
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#include <asm/kmap_types.h>
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#include <asm/uaccess.h>
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@ -70,7 +71,7 @@ struct kioctx_cpu {
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};
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struct kioctx {
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atomic_t users;
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struct percpu_ref users;
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atomic_t dead;
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/* This needs improving */
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@ -103,7 +104,7 @@ struct kioctx {
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long nr_pages;
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struct rcu_head rcu_head;
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struct work_struct rcu_work;
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struct work_struct free_work;
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struct {
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/*
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@ -403,8 +404,9 @@ static void free_ioctx_rcu(struct rcu_head *head)
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* and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
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* now it's safe to cancel any that need to be.
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*/
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static void free_ioctx(struct kioctx *ctx)
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static void free_ioctx(struct work_struct *work)
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{
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struct kioctx *ctx = container_of(work, struct kioctx, free_work);
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struct aio_ring *ring;
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struct io_event res;
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struct kiocb *req;
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@ -462,10 +464,12 @@ static void free_ioctx(struct kioctx *ctx)
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call_rcu(&ctx->rcu_head, free_ioctx_rcu);
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}
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static void put_ioctx(struct kioctx *ctx)
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static void free_ioctx_ref(struct percpu_ref *ref)
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{
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if (unlikely(atomic_dec_and_test(&ctx->users)))
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free_ioctx(ctx);
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struct kioctx *ctx = container_of(ref, struct kioctx, users);
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INIT_WORK(&ctx->free_work, free_ioctx);
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schedule_work(&ctx->free_work);
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}
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/* ioctx_alloc
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@ -505,8 +509,9 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
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ctx->max_reqs = nr_events;
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atomic_set(&ctx->users, 2);
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atomic_set(&ctx->dead, 0);
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if (percpu_ref_init(&ctx->users, free_ioctx_ref))
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goto out_freectx;
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spin_lock_init(&ctx->ctx_lock);
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spin_lock_init(&ctx->completion_lock);
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mutex_init(&ctx->ring_lock);
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@ -516,7 +521,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
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ctx->cpu = alloc_percpu(struct kioctx_cpu);
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if (!ctx->cpu)
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goto out_freectx;
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goto out_freeref;
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if (aio_setup_ring(ctx) < 0)
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goto out_freepcpu;
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@ -535,6 +540,8 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
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aio_nr += ctx->max_reqs;
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spin_unlock(&aio_nr_lock);
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percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */
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/* now link into global list. */
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spin_lock(&mm->ioctx_lock);
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hlist_add_head_rcu(&ctx->list, &mm->ioctx_list);
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@ -549,6 +556,8 @@ out_cleanup:
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aio_free_ring(ctx);
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out_freepcpu:
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free_percpu(ctx->cpu);
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out_freeref:
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free_percpu(ctx->users.pcpu_count);
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out_freectx:
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if (ctx->aio_ring_file)
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fput(ctx->aio_ring_file);
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@ -557,22 +566,6 @@ out_freectx:
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return ERR_PTR(err);
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}
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static void kill_ioctx_work(struct work_struct *work)
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{
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struct kioctx *ctx = container_of(work, struct kioctx, rcu_work);
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wake_up_all(&ctx->wait);
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put_ioctx(ctx);
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}
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static void kill_ioctx_rcu(struct rcu_head *head)
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{
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struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
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INIT_WORK(&ctx->rcu_work, kill_ioctx_work);
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schedule_work(&ctx->rcu_work);
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}
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/* kill_ioctx
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* Cancels all outstanding aio requests on an aio context. Used
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* when the processes owning a context have all exited to encourage
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@ -582,6 +575,8 @@ static void kill_ioctx(struct kioctx *ctx)
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{
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if (!atomic_xchg(&ctx->dead, 1)) {
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hlist_del_rcu(&ctx->list);
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/* percpu_ref_kill() will do the necessary call_rcu() */
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wake_up_all(&ctx->wait);
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/*
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* It'd be more correct to do this in free_ioctx(), after all
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@ -598,8 +593,7 @@ static void kill_ioctx(struct kioctx *ctx)
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if (ctx->mmap_size)
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vm_munmap(ctx->mmap_base, ctx->mmap_size);
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/* Between hlist_del_rcu() and dropping the initial ref */
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call_rcu(&ctx->rcu_head, kill_ioctx_rcu);
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percpu_ref_kill(&ctx->users);
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}
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}
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@ -633,12 +627,6 @@ void exit_aio(struct mm_struct *mm)
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struct hlist_node *n;
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hlist_for_each_entry_safe(ctx, n, &mm->ioctx_list, list) {
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if (1 != atomic_read(&ctx->users))
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printk(KERN_DEBUG
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"exit_aio:ioctx still alive: %d %d %d\n",
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atomic_read(&ctx->users),
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atomic_read(&ctx->dead),
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atomic_read(&ctx->reqs_available));
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/*
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* We don't need to bother with munmap() here -
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* exit_mmap(mm) is coming and it'll unmap everything.
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@ -757,7 +745,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
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hlist_for_each_entry_rcu(ctx, &mm->ioctx_list, list) {
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if (ctx->user_id == ctx_id) {
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atomic_inc(&ctx->users);
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percpu_ref_get(&ctx->users);
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ret = ctx;
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break;
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}
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@ -1054,7 +1042,7 @@ SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
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ret = put_user(ioctx->user_id, ctxp);
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if (ret)
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kill_ioctx(ioctx);
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put_ioctx(ioctx);
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percpu_ref_put(&ioctx->users);
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}
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out:
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@ -1072,7 +1060,7 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
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struct kioctx *ioctx = lookup_ioctx(ctx);
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if (likely(NULL != ioctx)) {
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kill_ioctx(ioctx);
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put_ioctx(ioctx);
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percpu_ref_put(&ioctx->users);
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return 0;
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}
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pr_debug("EINVAL: io_destroy: invalid context id\n");
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@ -1394,7 +1382,7 @@ long do_io_submit(aio_context_t ctx_id, long nr,
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}
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blk_finish_plug(&plug);
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put_ioctx(ctx);
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percpu_ref_put(&ctx->users);
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return i ? i : ret;
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}
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@ -1483,7 +1471,7 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
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ret = -EFAULT;
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}
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put_ioctx(ctx);
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percpu_ref_put(&ctx->users);
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return ret;
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}
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@ -1512,7 +1500,7 @@ SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
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if (likely(ioctx)) {
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if (likely(min_nr <= nr && min_nr >= 0))
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ret = read_events(ioctx, min_nr, nr, events, timeout);
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put_ioctx(ioctx);
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percpu_ref_put(&ioctx->users);
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}
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return ret;
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}
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