Re: [PATCH] crypto: allow to assign gfp_t for __crypto_alloc_tfm

From: Jaegeuk Kim
Date: Tue May 19 2015 - 03:13:30 EST


On Tue, May 19, 2015 at 02:59:29PM +0800, Herbert Xu wrote:
> On Mon, May 18, 2015 at 11:58:12PM -0700, Jaegeuk Kim wrote:
> >
> > > So where does the key get generated? The crypto tfm should be
> > > allocated when you generate the key.
> >
> > In fs/ext4/crypto.c,
> >
> > - writepage
> > - ext4_encrypt
> > - ext4_get_crypto_ctx
> > - crypto_alloc_ablkcipher
> > - ext4_page_crypto
> > - crypto_ablkcipher_setkey
> > - ablkcipher_request_alloc(GFP_NOFS)
> > - ablkcipher_request_set_crypt(PAGE_CACHE_SIZE)
> > - crypto_ablkcipher_encrypt
> >
> > - end_io
> > - crypto_free_tfm
>
> No that's where you set the key, not where you generate the key.

The key generation is done by ext4_generate_encryption_key in
fs/ext4/crypto_key.c.
And, ext4_file_mmap and ext4_file_open trigger it.

> --
> Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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