[LU-13783] Support for linux kernel version 5.8

Duplicate — Tue, 5 Jul 2022 22:13:35 +0000

Now that Linux 5.8 is in the stablization phase it makes sense to support compiling against it.

There are several changes that we need to adjust for. Some are easy, some require more work.

Linux 5.8:

removes the fmr_pool API.
doesn't use mmap_sem directly any more - use "mmap_read_lock()" and similar
kernel_setsockopt() has gone - need to use more direct access.
rdma_reject() needs a new "reason for reject" arg
NR_UNSTABLE_NFS has gone. Use NR_WRITEBACK instead
'dummy_context' in fscrypt has changed to "get_dummy_context", and fscrypt_dummy_context is now fsctype_get_dummy_context
unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()

Also:

__vmalloc() now only has 2 args.
FIELD_SIZEOF is gone, use sizeof_field
blkcipher is gone,, use skcipher
cached rb_tree changes
sysctl handlers like proc_doinvec now take a kernel pointer rather than a __user pointer

Whamcloud Community JIRA