RDMA/ucma: Remove unnecessary locking of file->ctx_list in close

During the file_operations release function it is already not possible
that write() can be running concurrently, remove the extra locking
around the ctx_list.

Link: https://lore.kernel.org/r/20200818120526.702120-3-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Jason Gunthorpe 2020-08-18 15:05:14 +03:00
parent ca2968c1ef
commit 07e266a775

View File

@ -1824,12 +1824,17 @@ static int ucma_close(struct inode *inode, struct file *filp)
struct ucma_file *file = filp->private_data;
struct ucma_context *ctx, *tmp;
mutex_lock(&file->mut);
/*
* ctx_list can only be mutated under the write(), which is no longer
* possible, so no locking needed.
*/
list_for_each_entry_safe(ctx, tmp, &file->ctx_list, list) {
xa_erase(&ctx_table, ctx->id);
mutex_lock(&file->mut);
ctx->destroying = 1;
mutex_unlock(&file->mut);
xa_erase(&ctx_table, ctx->id);
flush_workqueue(file->close_wq);
/* At that step once ctx was marked as destroying and workqueue
* was flushed we are safe from any inflights handlers that
@ -1849,9 +1854,7 @@ static int ucma_close(struct inode *inode, struct file *filp)
}
ucma_free_ctx(ctx);
mutex_lock(&file->mut);
}
mutex_unlock(&file->mut);
destroy_workqueue(file->close_wq);
kfree(file);
return 0;