From: Johannes Thumshirn <jthumshirn@suse.de>
To: dsterba@suse.cz, Linux BTRFS Mailinglist <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH 14/17] btrfs: directly call into crypto framework for checsumming
Date: Mon, 13 May 2019 15:01:11 +0200 [thread overview]
Message-ID: <20190513130111.GD18838@x250.microfocus.com> (raw)
In-Reply-To: <20190513130003.GD20156@suse.cz>
On Mon, May 13, 2019 at 03:00:03PM +0200, David Sterba wrote:
> On Fri, May 10, 2019 at 01:15:44PM +0200, Johannes Thumshirn wrote:
> > Currently btrfs_csum_data() relied on the crc32c() wrapper around the crypto
> > framework for calculating the CRCs.
> >
> > As we have our own crypto_shash structure in the fs_info now, we can
> > directly call into the crypto framework without going trough the wrapper.
> >
> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> > ---
> > fs/btrfs/disk-io.c | 28 ++++++++++++++++++++++++++--
> > 1 file changed, 26 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> > index fb0b06b7b9f6..0c9ac7b45ce8 100644
> > --- a/fs/btrfs/disk-io.c
> > +++ b/fs/btrfs/disk-io.c
> > @@ -253,12 +253,36 @@ struct extent_map *btree_get_extent(struct btrfs_inode *inode,
> > u32 btrfs_csum_data(struct btrfs_fs_info *fs_info, const char *data,
> > u32 seed, size_t len)
> > {
> > - return crc32c(seed, data, len);
> > + SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
> > + u32 *ctx = (u32 *)shash_desc_ctx(shash);
> > + u32 retval;
> > + int err;
> > +
> > + shash->tfm = fs_info->csum_shash;
> > + shash->flags = 0;
> > + *ctx = seed;
> > +
> > + err = crypto_shash_update(shash, data, len);
> > + ASSERT(err);
> > +
> > + retval = *ctx;
> > + barrier_data(ctx);
> > +
> > + return retval;
>
> I unfortunatelly had a dive into the crypto API calls and since then I'm
> biased against using it (too much indirection and extra memory
> references). So my idea of this function is:
>
> switch (fs_info->csum_type) {
> case CRC32:
> ... calculate crc32c;
> break;
> case SHA256:
> ... calculate sha56;
> break;
> }
>
> with direct calls to the hash primitives rather than thravelling trough
> the shash.
well at least the crc3c2() call we use does nothing else (from
lib/libcrc32c.c):
u32 crc32c(u32 crc, const void *address, unsigned int length)
{
SHASH_DESC_ON_STACK(shash, tfm);
u32 ret, *ctx = (u32 *)shash_desc_ctx(shash);
int err;
shash->tfm = tfm;
shash->flags = 0;
*ctx = crc;
err = crypto_shash_update(shash, address, length);
BUG_ON(err);
ret = *ctx;
barrier_data(ctx);
return ret;
}
EXPORT_SYMBOL(crc32c);
--
Johannes Thumshirn SUSE Labs Filesystems
jthumshirn@suse.de +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
next prev parent reply other threads:[~2019-05-13 13:01 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 11:15 [PATCH 00/17] Add support for SHA-256 checksums Johannes Thumshirn
2019-05-10 11:15 ` [PATCH 01/17] btrfs: use btrfs_csum_data() instead of directly calling crc32c Johannes Thumshirn
2019-05-10 16:16 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 02/17] btrfs: resurrect btrfs_crc32c() Johannes Thumshirn
2019-05-10 16:16 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 03/17] btrfs: use btrfs_crc32c() instead of btrfs_extref_hash() Johannes Thumshirn
2019-05-10 13:03 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 04/17] btrfs: use btrfs_crc32c() instead of btrfs_name_hash() Johannes Thumshirn
2019-05-10 12:56 ` Chris Mason
2019-05-13 7:04 ` Johannes Thumshirn
2019-05-10 11:15 ` [PATCH 05/17] btrfs: don't assume ordered sums to be 4 bytes Johannes Thumshirn
2019-05-10 13:25 ` Nikolay Borisov
2019-05-10 13:27 ` Nikolay Borisov
2019-05-13 7:06 ` Johannes Thumshirn
2019-05-10 11:15 ` [PATCH 06/17] btrfs: dont assume compressed_bio " Johannes Thumshirn
2019-05-10 11:15 ` [PATCH 07/17] btrfs: use btrfs_crc32c{,_final}() in for free space cache Johannes Thumshirn
2019-05-10 13:27 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 08/17] btrfs: format checksums according to type for printing Johannes Thumshirn
2019-05-10 13:28 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 09/17] btrfs: add common checksum type validation Johannes Thumshirn
2019-05-10 13:37 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 10/17] btrfs: check for supported superblock checksum type before checksum validation Johannes Thumshirn
2019-05-10 13:37 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 11/17] btrfs: Simplify btrfs_check_super_csum() and get rid of size assumptions Johannes Thumshirn
2019-05-10 13:41 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 12/17] btrfs: add boilerplate code for directly including the crypto framework Johannes Thumshirn
2019-05-10 16:28 ` Nikolay Borisov
2019-05-10 11:15 ` [PATCH 13/17] btrfs: pass in an fs_info to btrfs_csum_{data,final}() Johannes Thumshirn
2019-05-10 11:15 ` [PATCH 14/17] btrfs: directly call into crypto framework for checsumming Johannes Thumshirn
2019-05-10 13:45 ` Chris Mason
2019-05-10 13:54 ` Chris Mason
2019-05-13 7:17 ` Johannes Thumshirn
2019-05-13 13:55 ` Chris Mason
2019-05-14 12:46 ` Johannes Thumshirn
2019-05-13 13:00 ` David Sterba
2019-05-13 13:01 ` Johannes Thumshirn [this message]
2019-05-13 14:30 ` David Sterba
2019-05-10 11:15 ` [PATCH 15/17] btrfs: remove assumption about csum type form btrfs_csum_{data,final}() Johannes Thumshirn
2019-05-13 12:56 ` David Sterba
2019-05-10 11:15 ` [PATCH 16/17] btrfs: remove assumption about csum type form btrfs_print_data_csum_error() Johannes Thumshirn
2019-05-10 11:15 ` [PATCH 17/17] btrfs: add sha256 as another checksum algorithm Johannes Thumshirn
2019-05-10 12:30 ` Nikolay Borisov
2019-05-13 7:11 ` Johannes Thumshirn
2019-05-13 12:54 ` David Sterba
2019-05-13 12:55 ` Johannes Thumshirn
2019-05-15 1:45 ` Jeff Mahoney
2019-05-13 12:55 ` David Sterba
2019-05-13 12:58 ` Johannes Thumshirn
2019-05-15 17:27 ` [PATCH 00/17] Add support for SHA-256 checksums David Sterba
2019-05-16 6:30 ` Paul Jones
2019-05-16 8:16 ` Nikolay Borisov
2019-05-16 8:20 ` Johannes Thumshirn
2019-05-17 18:36 ` Diego Calleja
2019-05-17 19:07 ` Johannes Thumshirn
2019-05-18 0:38 ` Adam Borowski
2019-05-20 7:47 ` Johannes Thumshirn
2019-05-20 11:34 ` Austin S. Hemmelgarn
2019-05-20 11:57 ` Johannes Thumshirn
2019-05-20 11:42 ` Austin S. Hemmelgarn
2019-05-30 12:21 ` David Sterba
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