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Revision 3f9400981691f6845e5c22b962500742b80a5484 authored by Jeff Layton on 31 March 2015, 16:03:28 UTC, committed by Trond Myklebust on 23 April 2015, 18:42:27 UTC 
sunrpc: make debugfs file creation failure non-fatal
 
v2: gracefully handle the case where some dentry pointers end up NULL
    and be more dilligent about zeroing out dentry pointers

We currently have a problem that SELinux policy is being enforced when
creating debugfs files. If a debugfs file is created as a side effect of
doing some syscall, then that creation can fail if the SELinux policy
for that process prevents it.

This seems wrong. We don't do that for files under /proc, for instance,
so Bruce has proposed a patch to fix that.

While discussing that patch however, Greg K.H. stated:

    "No kernel code should care / fail if a debugfs function fails, so
     please fix up the sunrpc code first."

This patch converts all of the sunrpc debugfs setup code to be void
return functins, and the callers to not look for errors from those
functions.

This should allow rpc_clnt and rpc_xprt creation to work, even if the
kernel fails to create debugfs files for some reason.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
1 parent 5d05e54
Raw File
lz4.c 
/*
 * Cryptographic API.
 *
 * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>

struct lz4_ctx {
	void *lz4_comp_mem;
};

static int lz4_init(struct crypto_tfm *tfm)
{
	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);

	ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS);
	if (!ctx->lz4_comp_mem)
		return -ENOMEM;

	return 0;
}

static void lz4_exit(struct crypto_tfm *tfm)
{
	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
	vfree(ctx->lz4_comp_mem);
}

static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
			    unsigned int slen, u8 *dst, unsigned int *dlen)
{
	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
	size_t tmp_len = *dlen;
	int err;

	err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem);

	if (err < 0)
		return -EINVAL;

	*dlen = tmp_len;
	return 0;
}

static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
			      unsigned int slen, u8 *dst, unsigned int *dlen)
{
	int err;
	size_t tmp_len = *dlen;
	size_t __slen = slen;

	err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len);
	if (err < 0)
		return -EINVAL;

	*dlen = tmp_len;
	return err;
}

static struct crypto_alg alg_lz4 = {
	.cra_name		= "lz4",
	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
	.cra_ctxsize		= sizeof(struct lz4_ctx),
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(alg_lz4.cra_list),
	.cra_init		= lz4_init,
	.cra_exit		= lz4_exit,
	.cra_u			= { .compress = {
	.coa_compress		= lz4_compress_crypto,
	.coa_decompress		= lz4_decompress_crypto } }
};

static int __init lz4_mod_init(void)
{
	return crypto_register_alg(&alg_lz4);
}

static void __exit lz4_mod_fini(void)
{
	crypto_unregister_alg(&alg_lz4);
}

module_init(lz4_mod_init);
module_exit(lz4_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZ4 Compression Algorithm");
MODULE_ALIAS_CRYPTO("lz4");
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