Merge git://git.kvack.org/~bcrl/aio-next
Pull aio updates from Ben LaHaise. * git://git.kvack.org/~bcrl/aio-next: aio: use iovec array rather than the single one aio: fix some comments aio: use the macro rather than the inline magic number aio: remove the needless registration of ring file's private_data aio: remove no longer needed preempt_disable() aio: kill the misleading rcu read locks in ioctx_add_table() and kill_ioctx() aio: change exit_aio() to load mm->ioctx_table once and avoid rcu_read_lock()
This commit is contained in:
Linus Torvalds
Коммит
da06df548e
86
fs/aio.c
86
fs/aio.c
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@ -192,7 +192,6 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
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}
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file->f_flags = O_RDWR;
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file->private_data = ctx;
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return file;
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}
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@ -202,7 +201,7 @@ static struct dentry *aio_mount(struct file_system_type *fs_type,
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static const struct dentry_operations ops = {
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.d_dname = simple_dname,
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};
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return mount_pseudo(fs_type, "aio:", NULL, &ops, 0xa10a10a1);
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return mount_pseudo(fs_type, "aio:", NULL, &ops, AIO_RING_MAGIC);
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}
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/* aio_setup
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@ -556,8 +555,7 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
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struct aio_ring *ring;
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spin_lock(&mm->ioctx_lock);
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rcu_read_lock();
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table = rcu_dereference(mm->ioctx_table);
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table = rcu_dereference_raw(mm->ioctx_table);
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while (1) {
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if (table)
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@ -565,7 +563,6 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
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if (!table->table[i]) {
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ctx->id = i;
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table->table[i] = ctx;
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rcu_read_unlock();
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spin_unlock(&mm->ioctx_lock);
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/* While kioctx setup is in progress,
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@ -579,8 +576,6 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
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}
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new_nr = (table ? table->nr : 1) * 4;
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rcu_read_unlock();
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spin_unlock(&mm->ioctx_lock);
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table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) *
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@ -591,8 +586,7 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
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table->nr = new_nr;
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spin_lock(&mm->ioctx_lock);
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rcu_read_lock();
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old = rcu_dereference(mm->ioctx_table);
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old = rcu_dereference_raw(mm->ioctx_table);
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if (!old) {
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rcu_assign_pointer(mm->ioctx_table, table);
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@ -739,12 +733,9 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
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spin_lock(&mm->ioctx_lock);
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rcu_read_lock();
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table = rcu_dereference(mm->ioctx_table);
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table = rcu_dereference_raw(mm->ioctx_table);
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WARN_ON(ctx != table->table[ctx->id]);
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table->table[ctx->id] = NULL;
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rcu_read_unlock();
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spin_unlock(&mm->ioctx_lock);
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/* percpu_ref_kill() will do the necessary call_rcu() */
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@ -793,40 +784,30 @@ EXPORT_SYMBOL(wait_on_sync_kiocb);
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*/
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void exit_aio(struct mm_struct *mm)
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{
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struct kioctx_table *table;
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struct kioctx *ctx;
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unsigned i = 0;
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struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
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int i;
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while (1) {
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rcu_read_lock();
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table = rcu_dereference(mm->ioctx_table);
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if (!table)
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return;
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do {
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if (!table || i >= table->nr) {
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rcu_read_unlock();
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rcu_assign_pointer(mm->ioctx_table, NULL);
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if (table)
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kfree(table);
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return;
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}
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ctx = table->table[i++];
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} while (!ctx);
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rcu_read_unlock();
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for (i = 0; i < table->nr; ++i) {
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struct kioctx *ctx = table->table[i];
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if (!ctx)
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continue;
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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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* Since aio_free_ring() uses non-zero ->mmap_size
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* as indicator that it needs to unmap the area,
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* just set it to 0; aio_free_ring() is the only
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* place that uses ->mmap_size, so it's safe.
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* We don't need to bother with munmap() here - exit_mmap(mm)
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* is coming and it'll unmap everything. And we simply can't,
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* this is not necessarily our ->mm.
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* Since kill_ioctx() uses non-zero ->mmap_size as indicator
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* that it needs to unmap the area, just set it to 0.
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*/
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ctx->mmap_size = 0;
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kill_ioctx(mm, ctx, NULL);
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}
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RCU_INIT_POINTER(mm->ioctx_table, NULL);
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kfree(table);
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}
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static void put_reqs_available(struct kioctx *ctx, unsigned nr)
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@ -834,10 +815,8 @@ static void put_reqs_available(struct kioctx *ctx, unsigned nr)
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struct kioctx_cpu *kcpu;
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unsigned long flags;
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preempt_disable();
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kcpu = this_cpu_ptr(ctx->cpu);
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local_irq_save(flags);
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kcpu = this_cpu_ptr(ctx->cpu);
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kcpu->reqs_available += nr;
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while (kcpu->reqs_available >= ctx->req_batch * 2) {
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@ -846,7 +825,6 @@ static void put_reqs_available(struct kioctx *ctx, unsigned nr)
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}
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local_irq_restore(flags);
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preempt_enable();
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}
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static bool get_reqs_available(struct kioctx *ctx)
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@ -855,10 +833,8 @@ static bool get_reqs_available(struct kioctx *ctx)
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bool ret = false;
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unsigned long flags;
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preempt_disable();
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kcpu = this_cpu_ptr(ctx->cpu);
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local_irq_save(flags);
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kcpu = this_cpu_ptr(ctx->cpu);
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if (!kcpu->reqs_available) {
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int old, avail = atomic_read(&ctx->reqs_available);
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@ -878,7 +854,6 @@ static bool get_reqs_available(struct kioctx *ctx)
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kcpu->reqs_available--;
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out:
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local_irq_restore(flags);
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preempt_enable();
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return ret;
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}
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@ -1047,7 +1022,7 @@ void aio_complete(struct kiocb *iocb, long res, long res2)
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}
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EXPORT_SYMBOL(aio_complete);
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/* aio_read_events
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/* aio_read_events_ring
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* Pull an event off of the ioctx's event ring. Returns the number of
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* events fetched
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*/
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@ -1270,12 +1245,12 @@ static ssize_t aio_setup_vectored_rw(struct kiocb *kiocb,
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if (compat)
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ret = compat_rw_copy_check_uvector(rw,
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(struct compat_iovec __user *)buf,
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*nr_segs, 1, *iovec, iovec);
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*nr_segs, UIO_FASTIOV, *iovec, iovec);
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else
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#endif
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ret = rw_copy_check_uvector(rw,
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(struct iovec __user *)buf,
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*nr_segs, 1, *iovec, iovec);
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*nr_segs, UIO_FASTIOV, *iovec, iovec);
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if (ret < 0)
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return ret;
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@ -1299,9 +1274,8 @@ static ssize_t aio_setup_single_vector(struct kiocb *kiocb,
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}
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/*
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* aio_setup_iocb:
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* Performs the initial checks and aio retry method
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* setup for the kiocb at the time of io submission.
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* aio_run_iocb:
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* Performs the initial checks and io submission.
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*/
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static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
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char __user *buf, bool compat)
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@ -1313,7 +1287,7 @@ static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
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fmode_t mode;
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aio_rw_op *rw_op;
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rw_iter_op *iter_op;
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struct iovec inline_vec, *iovec = &inline_vec;
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struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
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struct iov_iter iter;
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switch (opcode) {
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@ -1348,7 +1322,7 @@ rw_common:
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if (!ret)
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ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes);
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if (ret < 0) {
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if (iovec != &inline_vec)
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if (iovec != inline_vecs)
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kfree(iovec);
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return ret;
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}
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@ -1395,7 +1369,7 @@ rw_common:
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return -EINVAL;
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}
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if (iovec != &inline_vec)
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if (iovec != inline_vecs)
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kfree(iovec);
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if (ret != -EIOCBQUEUED) {
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