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dm integrity: various small changes and cleanups
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Some coding style changes.

Fix a bug that the array test_tag has insufficient size if the digest
size of internal has is bigger than the tag size.

The function __fls is undefined for zero argument, this patch fixes
undefined behavior if the user sets zero interleave_sectors.

Fix the limit of optional arguments to 8.

Don't allocate crypt_data on the stack to avoid a BUG with debug kernel.

Rename all optional argument names to have underscores rather than
dashes.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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Mikulas Patocka authored and Mike Snitzer committed Apr 24, 2017
1 parent e2460f2 commit 56b67a4
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20 changes: 10 additions & 10 deletions Documentation/device-mapper/dm-integrity.txt
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,35 +69,35 @@ Target arguments:

Additional arguments:

journal-sectors:number
journal_sectors:number
The size of journal, this argument is used only if formatting the
device. If the device is already formatted, the value from the
superblock is used.

interleave-sectors:number
interleave_sectors:number
The number of interleaved sectors. This values is rounded down to
a power of two. If the device is already formatted, the value from
the superblock is used.

buffer-sectors:number
buffer_sectors:number
The number of sectors in one buffer. The value is rounded down to
a power of two.

The tag area is accessed using buffers, the buffer size is
configurable. The large buffer size means that the I/O size will
be larger, but there could be less I/Os issued.

journal-watermark:number
journal_watermark:number
The journal watermark in percents. When the size of the journal
exceeds this watermark, the thread that flushes the journal will
be started.

commit-time:number
commit_time:number
Commit time in milliseconds. When this time passes, the journal is
written. The journal is also written immediatelly if the FLUSH
request is received.

internal-hash:algorithm(:key) (the key is optional)
internal_hash:algorithm(:key) (the key is optional)
Use internal hash or crc.
When this argument is used, the dm-integrity target won't accept
integrity tags from the upper target, but it will automatically
Expand All @@ -113,7 +113,7 @@ internal-hash:algorithm(:key) (the key is optional)
from an upper layer target, such as dm-crypt. The upper layer
target should check the validity of the integrity tags.

journal-crypt:algorithm(:key) (the key is optional)
journal_crypt:algorithm(:key) (the key is optional)
Encrypt the journal using given algorithm to make sure that the
attacker can't read the journal. You can use a block cipher here
(such as "cbc(aes)") or a stream cipher (for example "chacha20",
Expand All @@ -125,7 +125,7 @@ journal-crypt:algorithm(:key) (the key is optional)
the size of files that were written. To protect against this
situation, you can encrypt the journal.

journal-mac:algorithm(:key) (the key is optional)
journal_mac:algorithm(:key) (the key is optional)
Protect sector numbers in the journal from accidental or malicious
modification. To protect against accidental modification, use a
crc algorithm, to protect against malicious modification, use a
Expand All @@ -137,7 +137,7 @@ journal-mac:algorithm(:key) (the key is optional)
this stage.


The journal mode (D/J), buffer-sectors, journal-watermark, commit-time can
The journal mode (D/J), buffer_sectors, journal_watermark, commit_time can
be changed when reloading the target (load an inactive table and swap the
tables with suspend and resume). The other arguments should not be changed
when reloading the target because the layout of disk data depend on them
Expand All @@ -158,7 +158,7 @@ The layout of the formatted block device:
provides (i.e. the size of the device minus the size of all
metadata and padding). The user of this target should not send
bios that access data beyond the "provided data sectors" limit.
* flags - a flag is set if journal-mac is used
* flags - a flag is set if journal_mac is used
* journal
The journal is divided into sections, each section contains:
* metadata area (4kiB), it contains journal entries
Expand Down
116 changes: 62 additions & 54 deletions drivers/md/dm-integrity.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,8 +27,8 @@
#define DEFAULT_JOURNAL_WATERMARK 50
#define DEFAULT_SYNC_MSEC 10000
#define DEFAULT_MAX_JOURNAL_SECTORS 131072
#define MIN_INTERLEAVE_SECTORS 3
#define MAX_INTERLEAVE_SECTORS 31
#define MIN_LOG2_INTERLEAVE_SECTORS 3
#define MAX_LOG2_INTERLEAVE_SECTORS 31
#define METADATA_WORKQUEUE_MAX_ACTIVE 16

/*
Expand Down Expand Up @@ -414,7 +414,7 @@ static void page_list_location(struct dm_integrity_c *ic, unsigned section, unsi
{
unsigned sector;

access_journal_check(ic, section, offset, false, "access_journal");
access_journal_check(ic, section, offset, false, "page_list_location");

sector = section * ic->journal_section_sectors + offset;

Expand Down Expand Up @@ -1211,7 +1211,7 @@ static void integrity_metadata(struct work_struct *w)
unsigned digest_size = crypto_shash_digestsize(ic->internal_hash);
struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
char *checksums;
unsigned extra_space = digest_size > ic->tag_size ? digest_size - ic->tag_size : 0;
unsigned extra_space = unlikely(digest_size > ic->tag_size) ? digest_size - ic->tag_size : 0;
char checksums_onstack[ic->tag_size + extra_space];
unsigned sectors_to_process = dio->range.n_sectors;
sector_t sector = dio->range.logical_sector;
Expand Down Expand Up @@ -1820,7 +1820,7 @@ static void do_journal_write(struct dm_integrity_c *ic, unsigned write_start,
unlikely(from_replay) &&
#endif
ic->internal_hash) {
unsigned char test_tag[ic->tag_size];
char test_tag[max(crypto_shash_digestsize(ic->internal_hash), ic->tag_size)];

integrity_sector_checksum(ic, sec + (l - j),
(char *)access_journal_data(ic, i, l), test_tag);
Expand Down Expand Up @@ -2135,11 +2135,11 @@ static void dm_integrity_status(struct dm_target *ti, status_type_t type,
arg_count += !!ic->journal_mac_alg.alg_string;
DMEMIT("%s %llu %u %c %u", ic->dev->name, (unsigned long long)ic->start,
ic->tag_size, ic->mode, arg_count);
DMEMIT(" journal-sectors:%u", ic->initial_sectors - SB_SECTORS);
DMEMIT(" interleave-sectors:%u", 1U << ic->sb->log2_interleave_sectors);
DMEMIT(" buffer-sectors:%u", 1U << ic->log2_buffer_sectors);
DMEMIT(" journal-watermark:%u", (unsigned)watermark_percentage);
DMEMIT(" commit-time:%u", ic->autocommit_msec);
DMEMIT(" journal_sectors:%u", ic->initial_sectors - SB_SECTORS);
DMEMIT(" interleave_sectors:%u", 1U << ic->sb->log2_interleave_sectors);
DMEMIT(" buffer_sectors:%u", 1U << ic->log2_buffer_sectors);
DMEMIT(" journal_watermark:%u", (unsigned)watermark_percentage);
DMEMIT(" commit_time:%u", ic->autocommit_msec);

#define EMIT_ALG(a, n) \
do { \
Expand All @@ -2149,9 +2149,9 @@ static void dm_integrity_status(struct dm_target *ti, status_type_t type,
DMEMIT(":%s", ic->a.key_string);\
} \
} while (0)
EMIT_ALG(internal_hash_alg, "internal-hash");
EMIT_ALG(journal_crypt_alg, "journal-crypt");
EMIT_ALG(journal_mac_alg, "journal-mac");
EMIT_ALG(internal_hash_alg, "internal_hash");
EMIT_ALG(journal_crypt_alg, "journal_crypt");
EMIT_ALG(journal_mac_alg, "journal_mac");
break;
}
}
Expand Down Expand Up @@ -2213,6 +2213,7 @@ static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sec
unsigned journal_sections;
int test_bit;

memset(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT);
memcpy(ic->sb->magic, SB_MAGIC, 8);
ic->sb->version = SB_VERSION;
ic->sb->integrity_tag_size = cpu_to_le16(ic->tag_size);
Expand All @@ -2225,9 +2226,11 @@ static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sec
journal_sections = 1;
ic->sb->journal_sections = cpu_to_le32(journal_sections);

if (!interleave_sectors)
interleave_sectors = DEFAULT_INTERLEAVE_SECTORS;
ic->sb->log2_interleave_sectors = __fls(interleave_sectors);
ic->sb->log2_interleave_sectors = max((__u8)MIN_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
ic->sb->log2_interleave_sectors = min((__u8)MAX_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
ic->sb->log2_interleave_sectors = max((__u8)MIN_LOG2_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
ic->sb->log2_interleave_sectors = min((__u8)MAX_LOG2_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);

ic->provided_data_sectors = 0;
for (test_bit = fls64(ic->device_sectors) - 1; test_bit >= 3; test_bit--) {
Expand All @@ -2238,7 +2241,7 @@ static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sec
ic->provided_data_sectors = prev_data_sectors;
}

if (!le64_to_cpu(ic->provided_data_sectors))
if (!ic->provided_data_sectors)
return -EINVAL;

ic->sb->provided_data_sectors = cpu_to_le64(ic->provided_data_sectors);
Expand Down Expand Up @@ -2444,6 +2447,12 @@ static int create_journal(struct dm_integrity_c *ic, char **error)
int r = 0;
unsigned i;
__u64 journal_pages, journal_desc_size, journal_tree_size;
unsigned char *crypt_data = NULL;

ic->commit_ids[0] = cpu_to_le64(0x1111111111111111ULL);
ic->commit_ids[1] = cpu_to_le64(0x2222222222222222ULL);
ic->commit_ids[2] = cpu_to_le64(0x3333333333333333ULL);
ic->commit_ids[3] = cpu_to_le64(0x4444444444444444ULL);

journal_pages = roundup((__u64)ic->journal_sections * ic->journal_section_sectors,
PAGE_SIZE >> SECTOR_SHIFT) >> (PAGE_SHIFT - SECTOR_SHIFT);
Expand Down Expand Up @@ -2541,7 +2550,13 @@ static int create_journal(struct dm_integrity_c *ic, char **error)
SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt);
unsigned char iv[ivsize];
unsigned crypt_len = roundup(ivsize, blocksize);
unsigned char crypt_data[crypt_len];

crypt_data = kmalloc(crypt_len, GFP_KERNEL);
if (!crypt_data) {
*error = "Unable to allocate crypt data";
r = -ENOMEM;
goto bad;
}

skcipher_request_set_tfm(req, ic->journal_crypt);

Expand Down Expand Up @@ -2630,38 +2645,38 @@ static int create_journal(struct dm_integrity_c *ic, char **error)
r = -ENOMEM;
}
bad:
kfree(crypt_data);
return r;
}

/*
* Construct a integrity mapping: <dev_path> <offset> <tag_size>
* Construct a integrity mapping
*
* Arguments:
* device
* offset from the start of the device
* tag size
* D - direct writes, J - journal writes
* D - direct writes, J - journal writes, R - recovery mode
* number of optional arguments
* optional arguments:
* journal-sectors
* interleave-sectors
* buffer-sectors
* journal-watermark
* commit-time
* internal-hash
* journal-crypt
* journal-mac
* journal_sectors
* interleave_sectors
* buffer_sectors
* journal_watermark
* commit_time
* internal_hash
* journal_crypt
* journal_mac
*/
static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
{
struct dm_integrity_c *ic;
char dummy;
int r;
unsigned i;
unsigned extra_args;
struct dm_arg_set as;
static struct dm_arg _args[] = {
{0, 7, "Invalid number of feature args"},
{0, 8, "Invalid number of feature args"},
};
unsigned journal_sectors, interleave_sectors, buffer_sectors, journal_watermark, sync_msec;
bool should_write_sb;
Expand All @@ -2683,11 +2698,6 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->private = ic;
ti->per_io_data_size = sizeof(struct dm_integrity_io);

ic->commit_ids[0] = cpu_to_le64(0x1111111111111111ULL);
ic->commit_ids[1] = cpu_to_le64(0x2222222222222222ULL);
ic->commit_ids[2] = cpu_to_le64(0x3333333333333333ULL);
ic->commit_ids[3] = cpu_to_le64(0x4444444444444444ULL);

ic->in_progress = RB_ROOT;
init_waitqueue_head(&ic->endio_wait);
bio_list_init(&ic->flush_bio_list);
Expand Down Expand Up @@ -2718,7 +2728,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
if (!strcmp(argv[3], "J") || !strcmp(argv[3], "D") || !strcmp(argv[3], "R"))
ic->mode = argv[3][0];
else {
ti->error = "Invalid mode (expecting J or D)";
ti->error = "Invalid mode (expecting J, D, R)";
r = -EINVAL;
goto bad;
}
Expand Down Expand Up @@ -2746,29 +2756,29 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->error = "Not enough feature arguments";
goto bad;
}
if (sscanf(opt_string, "journal-sectors:%u%c", &val, &dummy) == 1)
if (sscanf(opt_string, "journal_sectors:%u%c", &val, &dummy) == 1)
journal_sectors = val;
else if (sscanf(opt_string, "interleave-sectors:%u%c", &val, &dummy) == 1)
else if (sscanf(opt_string, "interleave_sectors:%u%c", &val, &dummy) == 1)
interleave_sectors = val;
else if (sscanf(opt_string, "buffer-sectors:%u%c", &val, &dummy) == 1)
else if (sscanf(opt_string, "buffer_sectors:%u%c", &val, &dummy) == 1)
buffer_sectors = val;
else if (sscanf(opt_string, "journal-watermark:%u%c", &val, &dummy) == 1 && val <= 100)
else if (sscanf(opt_string, "journal_watermark:%u%c", &val, &dummy) == 1 && val <= 100)
journal_watermark = val;
else if (sscanf(opt_string, "commit-time:%u%c", &val, &dummy) == 1)
else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1)
sync_msec = val;
else if (!memcmp(opt_string, "internal-hash:", strlen("internal-hash:"))) {
else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
"Invalid internal-hash argument");
"Invalid internal_hash argument");
if (r)
goto bad;
} else if (!memcmp(opt_string, "journal-crypt:", strlen("journal-crypt:"))) {
} else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
"Invalid journal-crypt argument");
"Invalid journal_crypt argument");
if (r)
goto bad;
} else if (!memcmp(opt_string, "journal-mac:", strlen("journal-mac:"))) {
} else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
r = get_alg_and_key(opt_string, &ic->journal_mac_alg, &ti->error,
"Invalid journal-mac argument");
"Invalid journal_mac argument");
if (r)
goto bad;
} else {
Expand Down Expand Up @@ -2877,12 +2887,10 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
should_write_sb = false;
if (memcmp(ic->sb->magic, SB_MAGIC, 8)) {
if (ic->mode != 'R') {
for (i = 0; i < 512; i += 8) {
if (*(__u64 *)((__u8 *)ic->sb + i)) {
r = -EINVAL;
ti->error = "The device is not initialized";
goto bad;
}
if (memchr_inv(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT)) {
r = -EINVAL;
ti->error = "The device is not initialized";
goto bad;
}
}

Expand All @@ -2906,8 +2914,8 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
goto bad;
}
/* make sure that ti->max_io_len doesn't overflow */
if (ic->sb->log2_interleave_sectors < MIN_INTERLEAVE_SECTORS ||
ic->sb->log2_interleave_sectors > MAX_INTERLEAVE_SECTORS) {
if (ic->sb->log2_interleave_sectors < MIN_LOG2_INTERLEAVE_SECTORS ||
ic->sb->log2_interleave_sectors > MAX_LOG2_INTERLEAVE_SECTORS) {
r = -EINVAL;
ti->error = "Invalid interleave_sectors in the superblock";
goto bad;
Expand Down

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