litmus-rt.git - The LITMUS^RT kernel.

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author	Heinz Mauelshagen <hjm@redhat.com>	2006-12-08 05:41:01 -0500
committer	Linus Torvalds <torvalds@woody.osdl.org>	2006-12-08 11:29:08 -0500
commit	f00b16ad665a9b489d46f612679181f3f914917b (patch)
tree	fc39bc1e04e063f8c5eda29f79d33a3194bb56fc /drivers/md
parent	5cd307c5655c0b76d563b5f3f911742a32746841 (diff)

[PATCH] dm io: fix bi_max_vecs

The existing code allocates an extra slot in bi_io_vec[] and uses it to store the region number. This patch hides the extra slot from bio_add_page() so the region number can't get overwritten. Also remove a hard-coded SECTOR_SHIFT and fix a typo in a comment. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Milan Broz <mbroz@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Diffstat (limited to 'drivers/md')

-rw-r--r--

drivers/md/dm-io.c

1 files changed, 9 insertions, 6 deletions

  *---------------------------------------------------------------*/
 static inline void bio_set_region(struct bio *bio, unsigned region)
 {
-        bio->bi_io_vec[bio->bi_max_vecs - 1].bv_len = region;
+        bio->bi_io_vec[bio->bi_max_vecs].bv_len = region;
 }
 static inline unsigned bio_get_region(struct bio *bio)
 {
-        return bio->bi_io_vec[bio->bi_max_vecs - 1].bv_len;
+        return bio->bi_io_vec[bio->bi_max_vecs].bv_len;
 }
 /*-----------------------------------------------------------------
                 zero_fill_bio(bio);
         dec_count(io, bio_get_region(bio), error);
+        bio->bi_max_vecs++;
         bio_put(bio);
         return 0;
         while (remaining) {
                 /*
-                 * Allocate a suitably sized bio, we add an extra
+                 * Allocate a suitably sized-bio: we add an extra
-                 * bvec for bio_get/set_region().
+                 * bvec for bio_get/set_region() and decrement bi_max_vecs
+                 * to hide it from bio_add_page().
                  */
-                num_bvecs = (remaining / (PAGE_SIZE >> 9)) + 2;
+                num_bvecs = (remaining / (PAGE_SIZE >> SECTOR_SHIFT)) + 2;
                 bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, _bios);
                 bio->bi_sector = where->sector + (where->count - remaining);
                 bio->bi_bdev = where->bdev;
                 bio->bi_end_io = endio;
                 bio->bi_private = io;
                 bio->bi_destructor = dm_bio_destructor;
+                bio->bi_max_vecs--;
                 bio_set_region(bio, region);
                 /*
         }
         /*
-         * Drop the extra refence that we were holding to avoid
+         * Drop the extra reference that we were holding to avoid
          * the io being completed too early.
          */
         dec_count(io, 0, 0);

/* LRW: as defined by Cyril Guyot in * http://grouper.ieee.org/groups/1619/email/pdf00017.pdf * * Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org> * * Based om ecb.c * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. */ /* This implementation is checked against the test vectors in the above * document and by a test vector provided by Ken Buchanan at * http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html * * The test vectors are included in the testing module tcrypt.[ch] */ #include <crypto/algapi.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/scatterlist.h> #include <linux/slab.h> #include <crypto/b128ops.h> #include <crypto/gf128mul.h> struct priv { struct crypto_cipher *child; /* optimizes multiplying a random (non incrementing, as at the * start of a new sector) value with key2, we could also have * used 4k optimization tables or no optimization at all. In the * latter case we would have to store key2 here */ struct gf128mul_64k *table; /* stores: * key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 }, * key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 } * key2*{ 0,0,...1,1,1,1,1 }, etc * needed for optimized multiplication of incrementing values * with key2 */ be128 mulinc[128]; }; static inline void setbit128_bbe(void *b, int bit) { __set_bit(bit ^ (0x80 - #ifdef __BIG_ENDIAN BITS_PER_LONG #else BITS_PER_BYTE #endif ), b); } static int setkey(struct crypto_tfm *parent, const u8 *key, unsigned int keylen) { struct priv *ctx = crypto_tfm_ctx(parent); struct crypto_cipher *child = ctx->child; int err, i; be128 tmp = { 0 }; int bsize = crypto_cipher_blocksize(child); crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) & CRYPTO_TFM_REQ_MASK); if ((err = crypto_cipher_setkey(child, key, keylen - bsize))) return err; crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) & CRYPTO_TFM_RES_MASK); if (ctx->table) gf128mul_free_64k(ctx->table); /* initialize multiplication table for Key2 */ ctx->table = gf128mul_init_64k_bbe((be128 *)(key + keylen - bsize)); if (!ctx->table) return -ENOMEM; /* initialize optimization table */ for (i = 0; i < 128; i++) { setbit128_bbe(&tmp, i); ctx->mulinc[i] = tmp; gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table); } return 0; } struct sinfo { be128 t; struct crypto_tfm *tfm; void (*fn)(struct crypto_tfm *, u8 *, const u8 *); }; static inline void inc(be128 *iv) { be64_add_cpu(&iv->b, 1); if (!iv->b) be64_add_cpu(&iv->a, 1); } static inline void lrw_round(struct sinfo *s, void *dst, const void *src) { be128_xor(dst, &s->t, src); /* PP <- T xor P */ s->fn(s->tfm, dst, dst); /* CC <- E(Key2,PP) */ be128_xor(dst, dst, &s->t); /* C <- T xor CC */ } /* this returns the number of consequative 1 bits starting * from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */ static inline int get_index128(be128 *block) { int x; __be32 *p = (__be32 *) block; for (p += 3, x = 0; x < 128; p--, x += 32) { u32 val = be32_to_cpup(p); if (!~val) continue; return x + ffz(val); } return x; } static int crypt(struct blkcipher_desc *d, struct blkcipher_walk *w, struct priv *ctx, void (*fn)(struct crypto_tfm *, u8 *, const u8 *)) { int err; unsigned int avail; const int bs = crypto_cipher_blocksize(ctx->child); struct sinfo s = { .tfm = crypto_cipher_tfm(ctx->child), .fn = fn }; be128 *iv; u8 *wsrc; u8 *wdst; err = blkcipher_walk_virt(d, w); if (!(avail = w->nbytes)) return err; wsrc = w->src.virt.addr; wdst = w->dst.virt.addr; /* calculate first value of T */ iv = (be128 *)w->iv; s.t = *iv; /* T <- I*Key2 */ gf128mul_64k_bbe(&s.t, ctx->table); goto first; for (;;) { do { /* T <- I*Key2, using the optimization * discussed in the specification */ be128_xor(&s.t, &s.t, &ctx->mulinc[get_index128(iv)]); inc(iv); first: lrw_round(&s, wdst, wsrc); wsrc += bs; wdst += bs; } while ((avail -= bs) >= bs); err = blkcipher_walk_done(d, w, avail); if (!(avail = w->nbytes)) break; wsrc = w->src.virt.addr; wdst = w->dst.virt.addr; } return err; } static int encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { struct priv *ctx = crypto_blkcipher_ctx(desc->tfm); struct blkcipher_walk w; blkcipher_walk_init(&w, dst, src, nbytes); return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->child)->cia_encrypt); } static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { struct priv *ctx = crypto_blkcipher_ctx(desc->tfm); struct blkcipher_walk w; blkcipher_walk_init(&w, dst, src, nbytes); return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->child)->cia_decrypt); } static int init_tfm(struct crypto_tfm *tfm) { struct crypto_cipher *cipher; struct crypto_instance *inst = (void *)tfm->__crt_alg; struct crypto_spawn *spawn = crypto_instance_ctx(inst); struct priv *ctx = crypto_tfm_ctx(tfm); u32 *flags = &tfm->crt_flags; cipher = crypto_spawn_cipher(spawn); if (IS_ERR(cipher)) return PTR_ERR(cipher); if (crypto_cipher_blocksize(cipher) != 16) { *flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; return -EINVAL; } ctx->child = cipher; return 0; } static void exit_tfm(struct crypto_tfm *tfm) { struct priv *ctx = crypto_tfm_ctx(tfm); if (ctx->table) gf128mul_free_64k(ctx->table); crypto_free_cipher(ctx->child); } static struct crypto_instance *alloc(struct rtattr **tb) { struct crypto_instance *inst; struct crypto_alg *alg; int err; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER); if (err) return ERR_PTR(err); alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, CRYPTO_ALG_TYPE_MASK); if (IS_ERR(alg)) return ERR_CAST(alg); inst = crypto_alloc_instance("lrw", alg); if (IS_ERR(inst)) goto out_put_alg; inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER; inst->alg.cra_priority = alg->cra_priority; inst->alg.cra_blocksize = alg->cra_blocksize; if (alg->cra_alignmask < 7) inst->alg.cra_alignmask = 7; else inst->alg.cra_alignmask = alg->cra_alignmask; inst->alg.cra_type = &crypto_blkcipher_type; if (!(alg->cra_blocksize % 4)) inst->alg.cra_alignmask |= 3; inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize; inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize + alg->cra_blocksize; inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize + alg->cra_blocksize; inst->alg.cra_ctxsize = sizeof(struct priv); inst->alg.cra_init = init_tfm; inst->alg.cra_exit = exit_tfm; inst->alg.cra_blkcipher.setkey = setkey; inst->alg.cra_blkcipher.encrypt = encrypt; inst->alg.cra_blkcipher.decrypt = decrypt; out_put_alg: crypto_mod_put(alg); return inst; } static void free(struct crypto_instance *inst) { crypto_drop_spawn(crypto_instance_ctx(inst)); kfree(inst); } static struct crypto_template crypto_tmpl = { .name = "lrw", .alloc = alloc, .free = free, .module = THIS_MODULE, }; static int __init crypto_module_init(void) { return crypto_register_template(&crypto_tmpl); } static void __exit crypto_module_exit(void) { crypto_unregister_template(&crypto_tmpl); } module_init(crypto_module_init); module_exit(crypto_module_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("LRW block cipher mode");


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