diff options
| -rw-r--r-- | drivers/infiniband/core/ucma.c | 92 | ||||
| -rw-r--r-- | include/rdma/rdma_user_cm.h | 13 |
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 */ |