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FreeBSD: Code cleanup in zio_crypt

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Address some unused value and control flow issues flagged by Coverity.

Unreachable code is pruned and unused values are avoided.
Some scattered sections are reordered for coherence.

We can assume kmem_alloc(n, KM_SLEEP) doesn't fail, so there is no need
to check if it returned NULL.  The allocated memory doesn't need to be
zeroed, other than the last iovec (the MAC).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10884
This commit is contained in:
Ryan Moeller 2020-09-03 21:15:32 +00:00 committed by Brian Behlendorf
parent 863e38453e
commit fa1912e80f
1 changed files with 76 additions and 145 deletions
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221
module/os/freebsd/zfs/zio_crypt.c
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@ -1234,8 +1234,7 @@ zio_crypt_do_indirect_mac_checksum_abd(boolean_t generate, abd_t *abd,
* accommodate some of the drivers, the authbuf needs to be logically before
* the data. This means that we need to copy the source to the destination,
* and set up an extra iovec_t at the beginning to handle the authbuf.
* It also means we'll only return one uio_t, which we do via the clumsy
* ifdef in the function declaration.
* It also means we'll only return one uio_t.
*/
/* ARGSUSED */
@ -1245,52 +1244,46 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
uio_t *out_uio, uint_t *enc_len, uint8_t **authbuf, uint_t *auth_len,
boolean_t *no_crypt)
{
int ret;
uint64_t txtype, lr_len;
uint_t nr_src, nr_dst, crypt_len;
uint_t aad_len = 0, nr_iovecs = 0, total_len = 0;
iovec_t *src_iovecs = NULL, *dst_iovecs = NULL;
uint8_t *aadbuf = zio_buf_alloc(datalen);
uint8_t *src, *dst, *slrp, *dlrp, *blkend, *aadp;
iovec_t *dst_iovecs;
zil_chain_t *zilc;
lr_t *lr;
uint8_t *aadbuf = zio_buf_alloc(datalen);
uint64_t txtype, lr_len;
uint_t crypt_len, nr_iovecs, vec;
uint_t aad_len = 0, total_len = 0;
/* cipherbuf always needs an extra iovec for the MAC */
if (encrypt) {
src = plainbuf;
dst = cipherbuf;
nr_src = 0;
nr_dst = 1;
} else {
src = cipherbuf;
dst = plainbuf;
nr_src = 1;
nr_dst = 0;
}
/*
* We need at least two iovecs -- one for the AAD,
* one for the MAC.
*/
bcopy(src, dst, datalen);
nr_dst = 2;
/* find the start and end record of the log block */
/* Find the start and end record of the log block. */
zilc = (zil_chain_t *)src;
slrp = src + sizeof (zil_chain_t);
aadp = aadbuf;
blkend = src + ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
/* calculate the number of encrypted iovecs we will need */
/*
* Calculate the number of encrypted iovecs we will need.
*/
/* We need at least two iovecs -- one for the AAD, one for the MAC. */
nr_iovecs = 2;
for (; slrp < blkend; slrp += lr_len) {
lr = (lr_t *)slrp;
if (!byteswap) {
txtype = lr->lrc_txtype;
lr_len = lr->lrc_reclen;
} else {
if (byteswap) {
txtype = BSWAP_64(lr->lrc_txtype);
lr_len = BSWAP_64(lr->lrc_reclen);
} else {
txtype = lr->lrc_txtype;
lr_len = lr->lrc_reclen;
}
nr_iovecs++;
@ -1298,27 +1291,7 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
nr_iovecs++;
}
nr_src = 0;
nr_dst += nr_iovecs;
/* allocate the iovec arrays */
if (nr_src != 0) {
src_iovecs = kmem_alloc(nr_src * sizeof (iovec_t), KM_SLEEP);
if (src_iovecs == NULL) {
ret = SET_ERROR(ENOMEM);
goto error;
}
bzero(src_iovecs, nr_src * sizeof (iovec_t));
}
if (nr_dst != 0) {
dst_iovecs = kmem_alloc(nr_dst * sizeof (iovec_t), KM_SLEEP);
if (dst_iovecs == NULL) {
ret = SET_ERROR(ENOMEM);
goto error;
}
bzero(dst_iovecs, nr_dst * sizeof (iovec_t));
}
dst_iovecs = kmem_alloc(nr_iovecs * sizeof (iovec_t), KM_SLEEP);
/*
* Copy the plain zil header over and authenticate everything except
@ -1326,18 +1299,20 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
* the embedded checksum will not have been calculated yet, so we don't
* authenticate that.
*/
bcopy(src, dst, sizeof (zil_chain_t));
bcopy(src, aadp, sizeof (zil_chain_t) - sizeof (zio_eck_t));
aadp += sizeof (zil_chain_t) - sizeof (zio_eck_t);
aad_len += sizeof (zil_chain_t) - sizeof (zio_eck_t);
/* loop over records again, filling in iovecs */
/* The first one will contain the authbuf */
nr_iovecs = 1;
slrp = src + sizeof (zil_chain_t);
dlrp = dst + sizeof (zil_chain_t);
/*
* Loop over records again, filling in iovecs.
*/
/* The first iovec will contain the authbuf. */
vec = 1;
for (; slrp < blkend; slrp += lr_len, dlrp += lr_len) {
lr = (lr_t *)slrp;
@ -1355,8 +1330,6 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
aadp += sizeof (lr_t);
aad_len += sizeof (lr_t);
ASSERT3P(dst_iovecs, !=, NULL);
/*
* If this is a TX_WRITE record we want to encrypt everything
* except the bp if exists. If the bp does exist we want to
@ -1365,9 +1338,9 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
if (txtype == TX_WRITE) {
crypt_len = sizeof (lr_write_t) -
sizeof (lr_t) - sizeof (blkptr_t);
dst_iovecs[nr_iovecs].iov_base = (char *)dlrp +
dst_iovecs[vec].iov_base = (char *)dlrp +
sizeof (lr_t);
dst_iovecs[nr_iovecs].iov_len = crypt_len;
dst_iovecs[vec].iov_len = crypt_len;
/* copy the bp now since it will not be encrypted */
bcopy(slrp + sizeof (lr_write_t) - sizeof (blkptr_t),
@ -1377,56 +1350,45 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
aadp, sizeof (blkptr_t));
aadp += sizeof (blkptr_t);
aad_len += sizeof (blkptr_t);
nr_iovecs++;
vec++;
total_len += crypt_len;
if (lr_len != sizeof (lr_write_t)) {
crypt_len = lr_len - sizeof (lr_write_t);
dst_iovecs[nr_iovecs].iov_base = (char *)
dst_iovecs[vec].iov_base = (char *)
dlrp + sizeof (lr_write_t);
dst_iovecs[nr_iovecs].iov_len = crypt_len;
nr_iovecs++;
dst_iovecs[vec].iov_len = crypt_len;
vec++;
total_len += crypt_len;
}
} else {
crypt_len = lr_len - sizeof (lr_t);
dst_iovecs[nr_iovecs].iov_base = (char *)dlrp +
dst_iovecs[vec].iov_base = (char *)dlrp +
sizeof (lr_t);
dst_iovecs[nr_iovecs].iov_len = crypt_len;
nr_iovecs++;
dst_iovecs[vec].iov_len = crypt_len;
vec++;
total_len += crypt_len;
}
}
*no_crypt = (nr_iovecs == 0);
/* The last iovec will contain the MAC. */
ASSERT3U(vec, ==, nr_iovecs - 1);
/* AAD */
dst_iovecs[0].iov_base = aadbuf;
dst_iovecs[0].iov_len = aad_len;
/* MAC */
dst_iovecs[vec].iov_base = 0;
dst_iovecs[vec].iov_len = 0;
*no_crypt = (vec == 1);
*enc_len = total_len;
*authbuf = aadbuf;
*auth_len = aad_len;
dst_iovecs[0].iov_base = aadbuf;
dst_iovecs[0].iov_len = aad_len;
out_uio->uio_iov = dst_iovecs;
out_uio->uio_iovcnt = nr_dst;
out_uio->uio_iovcnt = nr_iovecs;
return (0);
error:
zio_buf_free(aadbuf, datalen);
if (src_iovecs != NULL)
kmem_free(src_iovecs, nr_src * sizeof (iovec_t));
if (dst_iovecs != NULL)
kmem_free(dst_iovecs, nr_dst * sizeof (iovec_t));
*enc_len = 0;
*authbuf = NULL;
*auth_len = 0;
*no_crypt = B_FALSE;
puio->uio_iov = NULL;
puio->uio_iovcnt = 0;
out_uio->uio_iov = NULL;
out_uio->uio_iovcnt = 0;
return (ret);
}
/*
@ -1438,29 +1400,22 @@ zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
uio_t *puio, uio_t *out_uio, uint_t *enc_len, uint8_t **authbuf,
uint_t *auth_len, boolean_t *no_crypt)
{
int ret;
uint_t nr_src, nr_dst, crypt_len;
uint_t aad_len = 0, nr_iovecs = 0, total_len = 0;
uint_t i, j, max_dnp = datalen >> DNODE_SHIFT;
iovec_t *src_iovecs = NULL, *dst_iovecs = NULL;
uint8_t *aadbuf = zio_buf_alloc(datalen);
uint8_t *src, *dst, *aadp;
dnode_phys_t *dnp, *adnp, *sdnp, *ddnp;
uint8_t *aadbuf = zio_buf_alloc(datalen);
iovec_t *dst_iovecs;
uint_t nr_iovecs, crypt_len, vec;
uint_t aad_len = 0, total_len = 0;
uint_t i, j, max_dnp = datalen >> DNODE_SHIFT;
if (encrypt) {
src = plainbuf;
dst = cipherbuf;
nr_src = 0;
nr_dst = 1;
} else {
src = cipherbuf;
dst = plainbuf;
nr_src = 1;
nr_dst = 0;
}
bcopy(src, dst, datalen);
nr_dst = 2;
sdnp = (dnode_phys_t *)src;
ddnp = (dnode_phys_t *)dst;
@ -1470,6 +1425,10 @@ zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
* Count the number of iovecs we will need to do the encryption by
* counting the number of bonus buffers that need to be encrypted.
*/
/* We need at least two iovecs -- one for the AAD, one for the MAC. */
nr_iovecs = 2;
for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
/*
* This block may still be byteswapped. However, all of the
@ -1484,34 +1443,17 @@ zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
}
}
nr_src = 0;
nr_dst += nr_iovecs;
if (nr_src != 0) {
src_iovecs = kmem_alloc(nr_src * sizeof (iovec_t), KM_SLEEP);
if (src_iovecs == NULL) {
ret = SET_ERROR(ENOMEM);
goto error;
}
bzero(src_iovecs, nr_src * sizeof (iovec_t));
}
if (nr_dst != 0) {
dst_iovecs = kmem_alloc(nr_dst * sizeof (iovec_t), KM_SLEEP);
if (dst_iovecs == NULL) {
ret = SET_ERROR(ENOMEM);
goto error;
}
bzero(dst_iovecs, nr_dst * sizeof (iovec_t));
}
nr_iovecs = 1;
dst_iovecs = kmem_alloc(nr_iovecs * sizeof (iovec_t), KM_SLEEP);
/*
* Iterate through the dnodes again, this time filling in the uios
* we allocated earlier. We also concatenate any data we want to
* authenticate onto aadbuf.
*/
/* The first iovec will contain the authbuf. */
vec = 1;
for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
dnp = &sdnp[i];
@ -1565,12 +1507,10 @@ zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
if (dnp->dn_type != DMU_OT_NONE &&
DMU_OT_IS_ENCRYPTED(dnp->dn_bonustype) &&
dnp->dn_bonuslen != 0) {
ASSERT3U(nr_iovecs, <, nr_dst);
ASSERT3P(dst_iovecs, !=, NULL);
dst_iovecs[nr_iovecs].iov_base = DN_BONUS(&ddnp[i]);
dst_iovecs[nr_iovecs].iov_len = crypt_len;
dst_iovecs[vec].iov_base = DN_BONUS(&ddnp[i]);
dst_iovecs[vec].iov_len = crypt_len;
nr_iovecs++;
vec++;
total_len += crypt_len;
} else {
bcopy(DN_BONUS(dnp), DN_BONUS(&ddnp[i]), crypt_len);
@ -1580,33 +1520,24 @@ zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
}
}
*no_crypt = (nr_iovecs == 0);
/* The last iovec will contain the MAC. */
ASSERT3U(vec, ==, nr_iovecs - 1);
/* AAD */
dst_iovecs[0].iov_base = aadbuf;
dst_iovecs[0].iov_len = aad_len;
/* MAC */
dst_iovecs[vec].iov_base = 0;
dst_iovecs[vec].iov_len = 0;
*no_crypt = (vec == 1);
*enc_len = total_len;
*authbuf = aadbuf;
*auth_len = aad_len;
dst_iovecs[0].iov_base = aadbuf;
dst_iovecs[0].iov_len = aad_len;
out_uio->uio_iov = dst_iovecs;
out_uio->uio_iovcnt = nr_dst;
out_uio->uio_iovcnt = nr_iovecs;
return (0);
error:
zio_buf_free(aadbuf, datalen);
if (src_iovecs != NULL)
kmem_free(src_iovecs, nr_src * sizeof (iovec_t));
if (dst_iovecs != NULL)
kmem_free(dst_iovecs, nr_dst * sizeof (iovec_t));
*enc_len = 0;
*authbuf = NULL;
*auth_len = 0;
*no_crypt = B_FALSE;
out_uio->uio_iov = NULL;
out_uio->uio_iovcnt = 0;
return (ret);
}
/* ARGSUSED */