aboutsummaryrefslogtreecommitdiff
path: root/drivers/md/dm-crypt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c506
1 files changed, 316 insertions, 190 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index bdbd34993a8..655d816760e 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1,6 +1,7 @@
/*
* Copyright (C) 2003 Christophe Saout <christophe@saout.de>
* Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
+ * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
@@ -22,17 +23,19 @@
#include "dm.h"
#define DM_MSG_PREFIX "crypt"
+#define MESG_STR(x) x, sizeof(x)
/*
* per bio private data
*/
struct crypt_io {
struct dm_target *target;
- struct bio *bio;
+ struct bio *base_bio;
struct bio *first_clone;
struct work_struct work;
atomic_t pending;
int error;
+ int post_process;
};
/*
@@ -63,6 +66,7 @@ struct crypt_iv_operations {
* Crypt: maps a linear range of a block device
* and encrypts / decrypts at the same time.
*/
+enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
struct crypt_config {
struct dm_dev *dev;
sector_t start;
@@ -73,6 +77,7 @@ struct crypt_config {
*/
mempool_t *io_pool;
mempool_t *page_pool;
+ struct bio_set *bs;
/*
* crypto related data
@@ -86,11 +91,12 @@ struct crypt_config {
char cipher[CRYPTO_MAX_ALG_NAME];
char chainmode[CRYPTO_MAX_ALG_NAME];
struct crypto_blkcipher *tfm;
+ unsigned long flags;
unsigned int key_size;
u8 key[0];
};
-#define MIN_IOS 256
+#define MIN_IOS 16
#define MIN_POOL_PAGES 32
#define MIN_BIO_PAGES 8
@@ -306,6 +312,14 @@ static int crypt_convert(struct crypt_config *cc,
return r;
}
+ static void dm_crypt_bio_destructor(struct bio *bio)
+ {
+ struct crypt_io *io = bio->bi_private;
+ struct crypt_config *cc = io->target->private;
+
+ bio_free(bio, cc->bs);
+ }
+
/*
* Generate a new unfragmented bio with the given size
* This should never violate the device limitations
@@ -315,34 +329,33 @@ static struct bio *
crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
struct bio *base_bio, unsigned int *bio_vec_idx)
{
- struct bio *bio;
+ struct bio *clone;
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
unsigned int i;
- /*
- * Use __GFP_NOMEMALLOC to tell the VM to act less aggressively and
- * to fail earlier. This is not necessary but increases throughput.
- * FIXME: Is this really intelligent?
- */
- if (base_bio)
- bio = bio_clone(base_bio, GFP_NOIO|__GFP_NOMEMALLOC);
- else
- bio = bio_alloc(GFP_NOIO|__GFP_NOMEMALLOC, nr_iovecs);
- if (!bio)
+ if (base_bio) {
+ clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);
+ __bio_clone(clone, base_bio);
+ } else
+ clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
+
+ if (!clone)
return NULL;
+ clone->bi_destructor = dm_crypt_bio_destructor;
+
/* if the last bio was not complete, continue where that one ended */
- bio->bi_idx = *bio_vec_idx;
- bio->bi_vcnt = *bio_vec_idx;
- bio->bi_size = 0;
- bio->bi_flags &= ~(1 << BIO_SEG_VALID);
+ clone->bi_idx = *bio_vec_idx;
+ clone->bi_vcnt = *bio_vec_idx;
+ clone->bi_size = 0;
+ clone->bi_flags &= ~(1 << BIO_SEG_VALID);
- /* bio->bi_idx pages have already been allocated */
- size -= bio->bi_idx * PAGE_SIZE;
+ /* clone->bi_idx pages have already been allocated */
+ size -= clone->bi_idx * PAGE_SIZE;
- for(i = bio->bi_idx; i < nr_iovecs; i++) {
- struct bio_vec *bv = bio_iovec_idx(bio, i);
+ for (i = clone->bi_idx; i < nr_iovecs; i++) {
+ struct bio_vec *bv = bio_iovec_idx(clone, i);
bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
if (!bv->bv_page)
@@ -353,7 +366,7 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
* return a partially allocated bio, the caller will then try
* to allocate additional bios while submitting this partial bio
*/
- if ((i - bio->bi_idx) == (MIN_BIO_PAGES - 1))
+ if ((i - clone->bi_idx) == (MIN_BIO_PAGES - 1))
gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
bv->bv_offset = 0;
@@ -362,13 +375,13 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
else
bv->bv_len = size;
- bio->bi_size += bv->bv_len;
- bio->bi_vcnt++;
+ clone->bi_size += bv->bv_len;
+ clone->bi_vcnt++;
size -= bv->bv_len;
}
- if (!bio->bi_size) {
- bio_put(bio);
+ if (!clone->bi_size) {
+ bio_put(clone);
return NULL;
}
@@ -376,13 +389,13 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
* Remember the last bio_vec allocated to be able
* to correctly continue after the splitting.
*/
- *bio_vec_idx = bio->bi_vcnt;
+ *bio_vec_idx = clone->bi_vcnt;
- return bio;
+ return clone;
}
static void crypt_free_buffer_pages(struct crypt_config *cc,
- struct bio *bio, unsigned int bytes)
+ struct bio *clone, unsigned int bytes)
{
unsigned int i, start, end;
struct bio_vec *bv;
@@ -396,19 +409,19 @@ static void crypt_free_buffer_pages(struct crypt_config *cc,
* A fix to the bi_idx issue in the kernel is in the works, so
* we will hopefully be able to revert to the cleaner solution soon.
*/
- i = bio->bi_vcnt - 1;
- bv = bio_iovec_idx(bio, i);
- end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - bio->bi_size;
+ i = clone->bi_vcnt - 1;
+ bv = bio_iovec_idx(clone, i);
+ end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - clone->bi_size;
start = end - bytes;
start >>= PAGE_SHIFT;
- if (!bio->bi_size)
- end = bio->bi_vcnt;
+ if (!clone->bi_size)
+ end = clone->bi_vcnt;
else
end >>= PAGE_SHIFT;
- for(i = start; i < end; i++) {
- bv = bio_iovec_idx(bio, i);
+ for (i = start; i < end; i++) {
+ bv = bio_iovec_idx(clone, i);
BUG_ON(!bv->bv_page);
mempool_free(bv->bv_page, cc->page_pool);
bv->bv_page = NULL;
@@ -432,7 +445,7 @@ static void dec_pending(struct crypt_io *io, int error)
if (io->first_clone)
bio_put(io->first_clone);
- bio_endio(io->bio, io->bio->bi_size, io->error);
+ bio_endio(io->base_bio, io->base_bio->bi_size, io->error);
mempool_free(io, cc->io_pool);
}
@@ -441,29 +454,179 @@ static void dec_pending(struct crypt_io *io, int error)
* kcryptd:
*
* Needed because it would be very unwise to do decryption in an
- * interrupt context, so bios returning from read requests get
- * queued here.
+ * interrupt context.
*/
static struct workqueue_struct *_kcryptd_workqueue;
+static void kcryptd_do_work(void *data);
-static void kcryptd_do_work(void *data)
+static void kcryptd_queue_io(struct crypt_io *io)
{
- struct crypt_io *io = (struct crypt_io *) data;
- struct crypt_config *cc = (struct crypt_config *) io->target->private;
+ INIT_WORK(&io->work, kcryptd_do_work, io);
+ queue_work(_kcryptd_workqueue, &io->work);
+}
+
+static int crypt_endio(struct bio *clone, unsigned int done, int error)
+{
+ struct crypt_io *io = clone->bi_private;
+ struct crypt_config *cc = io->target->private;
+ unsigned read_io = bio_data_dir(clone) == READ;
+
+ /*
+ * free the processed pages, even if
+ * it's only a partially completed write
+ */
+ if (!read_io)
+ crypt_free_buffer_pages(cc, clone, done);
+
+ /* keep going - not finished yet */
+ if (unlikely(clone->bi_size))
+ return 1;
+
+ if (!read_io)
+ goto out;
+
+ if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
+ error = -EIO;
+ goto out;
+ }
+
+ bio_put(clone);
+ io->post_process = 1;
+ kcryptd_queue_io(io);
+ return 0;
+
+out:
+ bio_put(clone);
+ dec_pending(io, error);
+ return error;
+}
+
+static void clone_init(struct crypt_io *io, struct bio *clone)
+{
+ struct crypt_config *cc = io->target->private;
+
+ clone->bi_private = io;
+ clone->bi_end_io = crypt_endio;
+ clone->bi_bdev = cc->dev->bdev;
+ clone->bi_rw = io->base_bio->bi_rw;
+}
+
+static void process_read(struct crypt_io *io)
+{
+ struct crypt_config *cc = io->target->private;
+ struct bio *base_bio = io->base_bio;
+ struct bio *clone;
+ sector_t sector = base_bio->bi_sector - io->target->begin;
+
+ atomic_inc(&io->pending);
+
+ /*
+ * The block layer might modify the bvec array, so always
+ * copy the required bvecs because we need the original
+ * one in order to decrypt the whole bio data *afterwards*.
+ */
+ clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
+ if (unlikely(!clone)) {
+ dec_pending(io, -ENOMEM);
+ return;
+ }
+
+ clone_init(io, clone);
+ clone->bi_destructor = dm_crypt_bio_destructor;
+ clone->bi_idx = 0;
+ clone->bi_vcnt = bio_segments(base_bio);
+ clone->bi_size = base_bio->bi_size;
+ clone->bi_sector = cc->start + sector;
+ memcpy(clone->bi_io_vec, bio_iovec(base_bio),
+ sizeof(struct bio_vec) * clone->bi_vcnt);
+
+ generic_make_request(clone);
+}
+
+static void process_write(struct crypt_io *io)
+{
+ struct crypt_config *cc = io->target->private;
+ struct bio *base_bio = io->base_bio;
+ struct bio *clone;
struct convert_context ctx;
- int r;
+ unsigned remaining = base_bio->bi_size;
+ sector_t sector = base_bio->bi_sector - io->target->begin;
+ unsigned bvec_idx = 0;
+
+ atomic_inc(&io->pending);
+
+ crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
+
+ /*
+ * The allocated buffers can be smaller than the whole bio,
+ * so repeat the whole process until all the data can be handled.
+ */
+ while (remaining) {
+ clone = crypt_alloc_buffer(cc, base_bio->bi_size,
+ io->first_clone, &bvec_idx);
+ if (unlikely(!clone)) {
+ dec_pending(io, -ENOMEM);
+ return;
+ }
+
+ ctx.bio_out = clone;
+
+ if (unlikely(crypt_convert(cc, &ctx) < 0)) {
+ crypt_free_buffer_pages(cc, clone, clone->bi_size);
+ bio_put(clone);
+ dec_pending(io, -EIO);
+ return;
+ }
+
+ clone_init(io, clone);
+ clone->bi_sector = cc->start + sector;
+
+ if (!io->first_clone) {
+ /*
+ * hold a reference to the first clone, because it
+ * holds the bio_vec array and that can't be freed
+ * before all other clones are released
+ */
+ bio_get(clone);
+ io->first_clone = clone;
+ }
+
+ remaining -= clone->bi_size;
+ sector += bio_sectors(clone);
+
+ /* prevent bio_put of first_clone */
+ if (remaining)
+ atomic_inc(&io->pending);
- crypt_convert_init(cc, &ctx, io->bio, io->bio,
- io->bio->bi_sector - io->target->begin, 0);
- r = crypt_convert(cc, &ctx);
+ generic_make_request(clone);
- dec_pending(io, r);
+ /* out of memory -> run queues */
+ if (remaining)
+ blk_congestion_wait(bio_data_dir(clone), HZ/100);
+ }
}
-static void kcryptd_queue_io(struct crypt_io *io)
+static void process_read_endio(struct crypt_io *io)
{
- INIT_WORK(&io->work, kcryptd_do_work, io);
- queue_work(_kcryptd_workqueue, &io->work);
+ struct crypt_config *cc = io->target->private;
+ struct convert_context ctx;
+
+ crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,
+ io->base_bio->bi_sector - io->target->begin, 0);
+
+ dec_pending(io, crypt_convert(cc, &ctx));
+}
+
+static void kcryptd_do_work(void *data)
+{
+ struct crypt_io *io = data;
+
+ if (io->post_process)
+ process_read_endio(io);
+ else if (bio_data_dir(io->base_bio) == READ)
+ process_read(io);
+ else
+ process_write(io);
}
/*
@@ -477,7 +640,7 @@ static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
buffer[2] = '\0';
- for(i = 0; i < size; i++) {
+ for (i = 0; i < size; i++) {
buffer[0] = *hex++;
buffer[1] = *hex++;
@@ -500,13 +663,38 @@ static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
{
unsigned int i;
- for(i = 0; i < size; i++) {
+ for (i = 0; i < size; i++) {
sprintf(hex, "%02x", *key);
hex += 2;
key++;
}
}
+static int crypt_set_key(struct crypt_config *cc, char *key)
+{
+ unsigned key_size = strlen(key) >> 1;
+
+ if (cc->key_size && cc->key_size != key_size)
+ return -EINVAL;
+
+ cc->key_size = key_size; /* initial settings */
+
+ if ((!key_size && strcmp(key, "-")) ||
+ (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
+ return -EINVAL;
+
+ set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
+
+ return 0;
+}
+
+static int crypt_wipe_key(struct crypt_config *cc)
+{
+ clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
+ memset(&cc->key, 0, cc->key_size * sizeof(u8));
+ return 0;
+}
+
/*
* Construct an encryption mapping:
* <cipher> <key> <iv_offset> <dev_path> <start>
@@ -539,16 +727,14 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
key_size = strlen(argv[1]) >> 1;
- cc = kmalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
+ cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
if (cc == NULL) {
ti->error =
"Cannot allocate transparent encryption context";
return -ENOMEM;
}
- cc->key_size = key_size;
- if ((!key_size && strcmp(argv[1], "-") != 0) ||
- (key_size && crypt_decode_key(cc->key, argv[1], key_size) < 0)) {
+ if (crypt_set_key(cc, argv[1])) {
ti->error = "Error decoding key";
goto bad1;
}
@@ -626,6 +812,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad4;
}
+ cc->bs = bioset_create(MIN_IOS, MIN_IOS, 4);
+ if (!cc->bs) {
+ ti->error = "Cannot allocate crypt bioset";
+ goto bad_bs;
+ }
+
if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
ti->error = "Error setting key";
goto bad5;
@@ -665,6 +857,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
return 0;
bad5:
+ bioset_free(cc->bs);
+bad_bs:
mempool_destroy(cc->page_pool);
bad4:
mempool_destroy(cc->io_pool);
@@ -684,6 +878,7 @@ static void crypt_dtr(struct dm_target *ti)
{
struct crypt_config *cc = (struct crypt_config *) ti->private;
+ bioset_free(cc->bs);
mempool_destroy(cc->page_pool);
mempool_destroy(cc->io_pool);
@@ -698,147 +893,21 @@ static void crypt_dtr(struct dm_target *ti)
kfree(cc);
}
-static int crypt_endio(struct bio *bio, unsigned int done, int error)
-{
- struct crypt_io *io = (struct crypt_io *) bio->bi_private;
- struct crypt_config *cc = (struct crypt_config *) io->target->private;
-
- if (bio_data_dir(bio) == WRITE) {
- /*
- * free the processed pages, even if
- * it's only a partially completed write
- */
- crypt_free_buffer_pages(cc, bio, done);
- }
-
- if (bio->bi_size)
- return 1;
-
- bio_put(bio);
-
- /*
- * successful reads are decrypted by the worker thread
- */
- if ((bio_data_dir(bio) == READ)
- && bio_flagged(bio, BIO_UPTODATE)) {
- kcryptd_queue_io(io);
- return 0;
- }
-
- dec_pending(io, error);
- return error;
-}
-
-static inline struct bio *
-crypt_clone(struct crypt_config *cc, struct crypt_io *io, struct bio *bio,
- sector_t sector, unsigned int *bvec_idx,
- struct convert_context *ctx)
-{
- struct bio *clone;
-
- if (bio_data_dir(bio) == WRITE) {
- clone = crypt_alloc_buffer(cc, bio->bi_size,
- io->first_clone, bvec_idx);
- if (clone) {
- ctx->bio_out = clone;
- if (crypt_convert(cc, ctx) < 0) {
- crypt_free_buffer_pages(cc, clone,
- clone->bi_size);
- bio_put(clone);
- return NULL;
- }
- }
- } else {
- /*
- * The block layer might modify the bvec array, so always
- * copy the required bvecs because we need the original
- * one in order to decrypt the whole bio data *afterwards*.
- */
- clone = bio_alloc(GFP_NOIO, bio_segments(bio));
- if (clone) {
- clone->bi_idx = 0;
- clone->bi_vcnt = bio_segments(bio);
- clone->bi_size = bio->bi_size;
- memcpy(clone->bi_io_vec, bio_iovec(bio),
- sizeof(struct bio_vec) * clone->bi_vcnt);
- }
- }
-
- if (!clone)
- return NULL;
-
- clone->bi_private = io;
- clone->bi_end_io = crypt_endio;
- clone->bi_bdev = cc->dev->bdev;
- clone->bi_sector = cc->start + sector;
- clone->bi_rw = bio->bi_rw;
-
- return clone;
-}
-
static int crypt_map(struct dm_target *ti, struct bio *bio,
union map_info *map_context)
{
- struct crypt_config *cc = (struct crypt_config *) ti->private;
- struct crypt_io *io = mempool_alloc(cc->io_pool, GFP_NOIO);
- struct convert_context ctx;
- struct bio *clone;
- unsigned int remaining = bio->bi_size;
- sector_t sector = bio->bi_sector - ti->begin;
- unsigned int bvec_idx = 0;
+ struct crypt_config *cc = ti->private;
+ struct crypt_io *io;
+ io = mempool_alloc(cc->io_pool, GFP_NOIO);
io->target = ti;
- io->bio = bio;
+ io->base_bio = bio;
io->first_clone = NULL;
- io->error = 0;
- atomic_set(&io->pending, 1); /* hold a reference */
-
- if (bio_data_dir(bio) == WRITE)
- crypt_convert_init(cc, &ctx, NULL, bio, sector, 1);
-
- /*
- * The allocated buffers can be smaller than the whole bio,
- * so repeat the whole process until all the data can be handled.
- */
- while (remaining) {
- clone = crypt_clone(cc, io, bio, sector, &bvec_idx, &ctx);
- if (!clone)
- goto cleanup;
-
- if (!io->first_clone) {
- /*
- * hold a reference to the first clone, because it
- * holds the bio_vec array and that can't be freed
- * before all other clones are released
- */
- bio_get(clone);
- io->first_clone = clone;
- }
- atomic_inc(&io->pending);
+ io->error = io->post_process = 0;
+ atomic_set(&io->pending, 0);
+ kcryptd_queue_io(io);
- remaining -= clone->bi_size;
- sector += bio_sectors(clone);
-
- generic_make_request(clone);
-
- /* out of memory -> run queues */
- if (remaining)
- blk_congestion_wait(bio_data_dir(clone), HZ/100);
- }
-
- /* drop reference, clones could have returned before we reach this */
- dec_pending(io, 0);
return 0;
-
-cleanup:
- if (io->first_clone) {
- dec_pending(io, -ENOMEM);
- return 0;
- }
-
- /* if no bio has been dispatched yet, we can directly return the error */
- mempool_free(io, cc->io_pool);
- return -ENOMEM;
}
static int crypt_status(struct dm_target *ti, status_type_t type,
@@ -883,14 +952,71 @@ static int crypt_status(struct dm_target *ti, status_type_t type,
return 0;
}
+static void crypt_postsuspend(struct dm_target *ti)
+{
+ struct crypt_config *cc = ti->private;
+
+ set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
+}
+
+static int crypt_preresume(struct dm_target *ti)
+{
+ struct crypt_config *cc = ti->private;
+
+ if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
+ DMERR("aborting resume - crypt key is not set.");
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
+static void crypt_resume(struct dm_target *ti)
+{
+ struct crypt_config *cc = ti->private;
+
+ clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
+}
+
+/* Message interface
+ * key set <key>
+ * key wipe
+ */
+static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
+{
+ struct crypt_config *cc = ti->private;
+
+ if (argc < 2)
+ goto error;
+
+ if (!strnicmp(argv[0], MESG_STR("key"))) {
+ if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
+ DMWARN("not suspended during key manipulation.");
+ return -EINVAL;
+ }
+ if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
+ return crypt_set_key(cc, argv[2]);
+ if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
+ return crypt_wipe_key(cc);
+ }
+
+error:
+ DMWARN("unrecognised message received.");
+ return -EINVAL;
+}
+
static struct target_type crypt_target = {
.name = "crypt",
- .version= {1, 1, 0},
+ .version= {1, 3, 0},
.module = THIS_MODULE,
.ctr = crypt_ctr,
.dtr = crypt_dtr,
.map = crypt_map,
.status = crypt_status,
+ .postsuspend = crypt_postsuspend,
+ .preresume = crypt_preresume,
+ .resume = crypt_resume,
+ .message = crypt_message,
};
static int __init dm_crypt_init(void)