[PATCH V3 rdma-next 3/4] RDMA/uverbs: Hoist the common process of disassociate_ucontext into ib core

From: Wei Hu (Xavier)
Date: Sat May 26 2018 - 04:09:52 EST


This patch hoisted the common process of disassociate_ucontext
callback function into ib core code, and these code are common
to ervery ib_device driver.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx>
---
drivers/infiniband/core/uverbs_main.c | 45 ++++++++++++++++++++++++++++++++++-
drivers/infiniband/hw/mlx4/main.c | 34 --------------------------
drivers/infiniband/hw/mlx5/main.c | 34 --------------------------
3 files changed, 44 insertions(+), 69 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 4445d8e..a0a1c70 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -41,6 +41,8 @@
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/task.h>
#include <linux/file.h>
#include <linux/cdev.h>
#include <linux/anon_inodes.h>
@@ -1090,6 +1092,47 @@ static void ib_uverbs_add_one(struct ib_device *device)
return;
}

+static void ib_uverbs_disassociate_ucontext(struct ib_ucontext *ibcontext)
+{
+ struct ib_device *ib_dev = ibcontext->device;
+ struct task_struct *owning_process = NULL;
+ struct mm_struct *owning_mm = NULL;
+
+ owning_process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
+ if (!owning_process)
+ return;
+
+ owning_mm = get_task_mm(owning_process);
+ if (!owning_mm) {
+ pr_info("no mm, disassociate ucontext is pending task termination\n");
+ while (1) {
+ put_task_struct(owning_process);
+ usleep_range(1000, 2000);
+ owning_process = get_pid_task(ibcontext->tgid,
+ PIDTYPE_PID);
+ if (!owning_process ||
+ owning_process->state == TASK_DEAD) {
+ pr_info("disassociate ucontext done, task was terminated\n");
+ /* in case task was dead need to release the
+ * task struct.
+ */
+ if (owning_process)
+ put_task_struct(owning_process);
+ return;
+ }
+ }
+ }
+
+ /* need to protect from a race on closing the vma as part of
+ * mlx5_ib_vma_close.
+ */
+ down_write(&owning_mm->mmap_sem);
+ ib_dev->disassociate_ucontext(ibcontext);
+ up_write(&owning_mm->mmap_sem);
+ mmput(owning_mm);
+ put_task_struct(owning_process);
+}
+
static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
struct ib_device *ib_dev)
{
@@ -1130,7 +1173,7 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
* (e.g mmput).
*/
ib_uverbs_event_handler(&file->event_handler, &event);
- ib_dev->disassociate_ucontext(ucontext);
+ ib_uverbs_disassociate_ucontext(ucontext);
mutex_lock(&file->cleanup_mutex);
ib_uverbs_cleanup_ucontext(file, ucontext, true);
mutex_unlock(&file->cleanup_mutex);
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index bf12394..59aed45 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -1189,40 +1189,10 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
int ret = 0;
struct vm_area_struct *vma;
struct mlx4_ib_ucontext *context = to_mucontext(ibcontext);
- struct task_struct *owning_process = NULL;
- struct mm_struct *owning_mm = NULL;
-
- owning_process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
- if (!owning_process)
- return;
-
- owning_mm = get_task_mm(owning_process);
- if (!owning_mm) {
- pr_info("no mm, disassociate ucontext is pending task termination\n");
- while (1) {
- /* make sure that task is dead before returning, it may
- * prevent a rare case of module down in parallel to a
- * call to mlx4_ib_vma_close.
- */
- put_task_struct(owning_process);
- usleep_range(1000, 2000);
- owning_process = get_pid_task(ibcontext->tgid,
- PIDTYPE_PID);
- if (!owning_process ||
- owning_process->state == TASK_DEAD) {
- pr_info("disassociate ucontext done, task was terminated\n");
- /* in case task was dead need to release the task struct */
- if (owning_process)
- put_task_struct(owning_process);
- return;
- }
- }
- }

/* need to protect from a race on closing the vma as part of
* mlx4_ib_vma_close().
*/
- down_write(&owning_mm->mmap_sem);
for (i = 0; i < HW_BAR_COUNT; i++) {
vma = context->hw_bar_info[i].vma;
if (!vma)
@@ -1241,10 +1211,6 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
/* context going to be destroyed, should not access ops any more */
context->hw_bar_info[i].vma->vm_ops = NULL;
}
-
- up_write(&owning_mm->mmap_sem);
- mmput(owning_mm);
- put_task_struct(owning_process);
}

static void mlx4_ib_set_vma_data(struct vm_area_struct *vma,
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index f3e7d7c..136d64f 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1965,38 +1965,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
struct vm_area_struct *vma;
struct mlx5_ib_vma_private_data *vma_private, *n;
struct mlx5_ib_ucontext *context = to_mucontext(ibcontext);
- struct task_struct *owning_process = NULL;
- struct mm_struct *owning_mm = NULL;

- owning_process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
- if (!owning_process)
- return;
-
- owning_mm = get_task_mm(owning_process);
- if (!owning_mm) {
- pr_info("no mm, disassociate ucontext is pending task termination\n");
- while (1) {
- put_task_struct(owning_process);
- usleep_range(1000, 2000);
- owning_process = get_pid_task(ibcontext->tgid,
- PIDTYPE_PID);
- if (!owning_process ||
- owning_process->state == TASK_DEAD) {
- pr_info("disassociate ucontext done, task was terminated\n");
- /* in case task was dead need to release the
- * task struct.
- */
- if (owning_process)
- put_task_struct(owning_process);
- return;
- }
- }
- }
-
- /* need to protect from a race on closing the vma as part of
- * mlx5_ib_vma_close.
- */
- down_write(&owning_mm->mmap_sem);
mutex_lock(&context->vma_private_list_mutex);
list_for_each_entry_safe(vma_private, n, &context->vma_private_list,
list) {
@@ -2013,9 +1982,6 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
kfree(vma_private);
}
mutex_unlock(&context->vma_private_list_mutex);
- up_write(&owning_mm->mmap_sem);
- mmput(owning_mm);
- put_task_struct(owning_process);
}

static inline char *mmap_cmd2str(enum mlx5_ib_mmap_cmd cmd)
--
1.9.1