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-rw-r--r--drivers/infiniband/core/ucma.c92
-rw-r--r--include/rdma/rdma_user_cm.h13
2 files changed, 104 insertions, 1 deletions
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 90d675ad9ec..15937eb38aa 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -31,6 +31,7 @@
*/
#include <linux/completion.h>
+#include <linux/file.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/idr.h>
@@ -991,6 +992,96 @@ out:
return ret;
}
+static void ucma_lock_files(struct ucma_file *file1, struct ucma_file *file2)
+{
+ /* Acquire mutex's based on pointer comparison to prevent deadlock. */
+ if (file1 < file2) {
+ mutex_lock(&file1->mut);
+ mutex_lock(&file2->mut);
+ } else {
+ mutex_lock(&file2->mut);
+ mutex_lock(&file1->mut);
+ }
+}
+
+static void ucma_unlock_files(struct ucma_file *file1, struct ucma_file *file2)
+{
+ if (file1 < file2) {
+ mutex_unlock(&file2->mut);
+ mutex_unlock(&file1->mut);
+ } else {
+ mutex_unlock(&file1->mut);
+ mutex_unlock(&file2->mut);
+ }
+}
+
+static void ucma_move_events(struct ucma_context *ctx, struct ucma_file *file)
+{
+ struct ucma_event *uevent, *tmp;
+
+ list_for_each_entry_safe(uevent, tmp, &ctx->file->event_list, list)
+ if (uevent->ctx == ctx)
+ list_move_tail(&uevent->list, &file->event_list);
+}
+
+static ssize_t ucma_migrate_id(struct ucma_file *new_file,
+ const char __user *inbuf,
+ int in_len, int out_len)
+{
+ struct rdma_ucm_migrate_id cmd;
+ struct rdma_ucm_migrate_resp resp;
+ struct ucma_context *ctx;
+ struct file *filp;
+ struct ucma_file *cur_file;
+ int ret = 0;
+
+ if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+ return -EFAULT;
+
+ /* Get current fd to protect against it being closed */
+ filp = fget(cmd.fd);
+ if (!filp)
+ return -ENOENT;
+
+ /* Validate current fd and prevent destruction of id. */
+ ctx = ucma_get_ctx(filp->private_data, cmd.id);
+ if (IS_ERR(ctx)) {
+ ret = PTR_ERR(ctx);
+ goto file_put;
+ }
+
+ cur_file = ctx->file;
+ if (cur_file == new_file) {
+ resp.events_reported = ctx->events_reported;
+ goto response;
+ }
+
+ /*
+ * Migrate events between fd's, maintaining order, and avoiding new
+ * events being added before existing events.
+ */
+ ucma_lock_files(cur_file, new_file);
+ mutex_lock(&mut);
+
+ list_move_tail(&ctx->list, &new_file->ctx_list);
+ ucma_move_events(ctx, new_file);
+ ctx->file = new_file;
+ resp.events_reported = ctx->events_reported;
+
+ mutex_unlock(&mut);
+ ucma_unlock_files(cur_file, new_file);
+
+response:
+ if (copy_to_user((void __user *)(unsigned long)cmd.response,
+ &resp, sizeof(resp)))
+ ret = -EFAULT;
+
+ ucma_put_ctx(ctx);
+file_put:
+ fput(filp);
+ return ret;
+}
+
static ssize_t (*ucma_cmd_table[])(struct ucma_file *file,
const char __user *inbuf,
int in_len, int out_len) = {
@@ -1012,6 +1103,7 @@ static ssize_t (*ucma_cmd_table[])(struct ucma_file *file,
[RDMA_USER_CM_CMD_NOTIFY] = ucma_notify,
[RDMA_USER_CM_CMD_JOIN_MCAST] = ucma_join_multicast,
[RDMA_USER_CM_CMD_LEAVE_MCAST] = ucma_leave_multicast,
+ [RDMA_USER_CM_CMD_MIGRATE_ID] = ucma_migrate_id
};
static ssize_t ucma_write(struct file *filp, const char __user *buf,
diff --git a/include/rdma/rdma_user_cm.h b/include/rdma/rdma_user_cm.h
index 9749c1b34d0..c55705460b8 100644
--- a/include/rdma/rdma_user_cm.h
+++ b/include/rdma/rdma_user_cm.h
@@ -60,7 +60,8 @@ enum {
RDMA_USER_CM_CMD_SET_OPTION,
RDMA_USER_CM_CMD_NOTIFY,
RDMA_USER_CM_CMD_JOIN_MCAST,
- RDMA_USER_CM_CMD_LEAVE_MCAST
+ RDMA_USER_CM_CMD_LEAVE_MCAST,
+ RDMA_USER_CM_CMD_MIGRATE_ID
};
/*
@@ -230,4 +231,14 @@ struct rdma_ucm_set_option {
__u32 optlen;
};
+struct rdma_ucm_migrate_id {
+ __u64 response;
+ __u32 id;
+ __u32 fd;
+};
+
+struct rdma_ucm_migrate_resp {
+ __u32 events_reported;
+};
+
#endif /* RDMA_USER_CM_H */