Re: [PATCH bpf-next v7 5/7] bpf: Implement bpf_local_storage for inodes

On 31.07.20 21:02, Martin KaFai Lau wrote:

On Fri, Jul 31, 2020 at 02:08:55PM +0200, KP Singh wrote:
[ ... ]

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+const struct bpf_map_ops inode_storage_map_ops = {

[...]

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btf  dump file /sys/kernel/btf/vmlinux | grep "STRUCT 'inode'"
"[915] STRUCT 'inode' size=984 vlen=48

So it seems like btf_id[0] and btf_id[1] are set to the BTF ID
for inode. Now I think this might just be a coincidence as
the next helper (bpf_inode_storage_delete) 
also has a BTF argument of type inode.

It seems the next BTF_ID_LIST(bpf_inode_storage_delete_btf_ids)
is not needed because they are the same.  I think one
BTF_ID_LIST(bpf_inode_btf_ids) can be used for both helpers.

Cool, yeah. I have fixed it and also for sock helpers. Will
send a new series out.

- KP

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and sure enough if I call:

bpf_inode_storage_delete from my selftests program, 
it does not load:

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./test_progs -t test_local_storage
[   20.577223] btf_ids[0]=0
[   20.577702] btf_ids[1]=915

Thanks for noticing this! 

- KP

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+
+const struct bpf_func_proto bpf_inode_storage_get_proto = {
+	.func		= bpf_inode_storage_get,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg4_type	= ARG_ANYTHING,
+	.btf_id		= bpf_inode_storage_get_btf_ids,
+};
+
+BTF_ID_LIST(bpf_inode_storage_delete_btf_ids)
+BTF_ID(struct, inode)
+
+const struct bpf_func_proto bpf_inode_storage_delete_proto = {
+	.func		= bpf_inode_storage_delete,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.btf_id		= bpf_inode_storage_delete_btf_ids,
+};