OpenSolaris_b135/uts/common/io/lofi.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* lofi (loopback file) driver - allows you to attach a file to a device,
* which can then be accessed through that device. The simple model is that
* you tell lofi to open a file, and then use the block device you get as
* you would any block device. lofi translates access to the block device
* into I/O on the underlying file. This is mostly useful for
* mounting images of filesystems.
*
* lofi is controlled through /dev/lofictl - this is the only device exported
* during attach, and is minor number 0. lofiadm communicates with lofi through
* ioctls on this device. When a file is attached to lofi, block and character
* devices are exported in /dev/lofi and /dev/rlofi. Currently, these devices
* are identified by their minor number, and the minor number is also used
* as the name in /dev/lofi. If we ever decide to support virtual disks,
* we'll have to divide the minor number space to identify fdisk partitions
* and slices, and the name will then be the minor number shifted down a
* few bits. Minor devices are tracked with state structures handled with
* ddi_soft_state(9F) for simplicity.
*
* A file attached to lofi is opened when attached and not closed until
* explicitly detached from lofi. This seems more sensible than deferring
* the open until the /dev/lofi device is opened, for a number of reasons.
* One is that any failure is likely to be noticed by the person (or script)
* running lofiadm. Another is that it would be a security problem if the
* file was replaced by another one after being added but before being opened.
*
* The only hard part about lofi is the ioctls. In order to support things
* like 'newfs' on a lofi device, it needs to support certain disk ioctls.
* So it has to fake disk geometry and partition information. More may need
* to be faked if your favorite utility doesn't work and you think it should
* (fdformat doesn't work because it really wants to know the type of floppy
* controller to talk to, and that didn't seem easy to fake. Or possibly even
* necessary, since we have mkfs_pcfs now).
*
* Normally, a lofi device cannot be detached if it is open (i.e. busy). To
* support simulation of hotplug events, an optional force flag is provided.
* If a lofi device is open when a force detach is requested, then the
* underlying file is closed and any subsequent operations return EIO. When the
* device is closed for the last time, it will be cleaned up at that time. In
* addition, the DKIOCSTATE ioctl will return DKIO_DEV_GONE when the device is
* detached but not removed.
*
* Known problems:
*
* UFS logging. Mounting a UFS filesystem image "logging"
* works for basic copy testing but wedges during a build of ON through
* that image. Some deadlock in lufs holding the log mutex and then
* getting stuck on a buf. So for now, don't do that.
*
* Direct I/O. Since the filesystem data is being cached in the buffer
* cache, _and_ again in the underlying filesystem, it's tempting to
* enable direct I/O on the underlying file. Don't, because that deadlocks.
* I think to fix the cache-twice problem we might need filesystem support.
*
* lofi on itself. The simple lock strategy (lofi_lock) precludes this
* because you'll be in lofi_ioctl, holding the lock when you open the
* file, which, if it's lofi, will grab lofi_lock. We prevent this for
* now, though not using ddi_soft_state(9F) would make it possible to
* do. Though it would still be silly.
*
* Interesting things to do:
*
* Allow multiple files for each device. A poor-man's metadisk, basically.
*
* Pass-through ioctls on block devices. You can (though it's not
* documented), give lofi a block device as a file name. Then we shouldn't
* need to fake a geometry, however, it may be relevant if you're replacing
* metadisk, or using lofi to get crypto.
* It makes sense to do lofiadm -c aes -a /dev/dsk/c0t0d0s4 /dev/lofi/1
* and then in /etc/vfstab have an entry for /dev/lofi/1 as /export/home.
* In fact this even makes sense if you have lofi "above" metadisk.
*
* Encryption:
* Each lofi device can have its own symmetric key and cipher.
* They are passed to us by lofiadm(1m) in the correct format for use
* with the misc/kcf crypto_* routines.
*
* Each block has its own IV, that is calculated in lofi_blk_mech(), based
* on the "master" key held in the lsp and the block number of the buffer.
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/sysmacros.h>
#include <sys/uio.h>
#include <sys/kmem.h>
#include <sys/cred.h>
#include <sys/mman.h>
#include <sys/errno.h>
#include <sys/aio_req.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/modctl.h>
#include <sys/conf.h>
#include <sys/debug.h>
#include <sys/vnode.h>
#include <sys/lofi.h>
#include <sys/fcntl.h>
#include <sys/pathname.h>
#include <sys/filio.h>
#include <sys/fdio.h>
#include <sys/open.h>
#include <sys/disp.h>
#include <vm/seg_map.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/zmod.h>
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <LzmaDec.h>
/*
* The basis for CRYOFF is derived from usr/src/uts/common/sys/fs/ufs_fs.h.
* Crypto metadata, if it exists, is located at the end of the boot block
* (BBOFF + BBSIZE, which is SBOFF). The super block and everything after
* is offset by the size of the crypto metadata which is handled by
* lsp->ls_crypto_offset.
*/
#define CRYOFF ((off_t)8192)
#define NBLOCKS_PROP_NAME "Nblocks"
#define SIZE_PROP_NAME "Size"
#define SETUP_C_DATA(cd, buf, len) \
(cd).cd_format = CRYPTO_DATA_RAW; \
(cd).cd_offset = 0; \
(cd).cd_miscdata = NULL; \
(cd).cd_length = (len); \
(cd).cd_raw.iov_base = (buf); \
(cd).cd_raw.iov_len = (len);
#define UIO_CHECK(uio) \
if (((uio)->uio_loffset % DEV_BSIZE) != 0 || \
((uio)->uio_resid % DEV_BSIZE) != 0) { \
return (EINVAL); \
}
static dev_info_t *lofi_dip = NULL;
static void *lofi_statep = NULL;
static kmutex_t lofi_lock; /* state lock */
/*
* Because lofi_taskq_nthreads limits the actual swamping of the device, the
* maxalloc parameter (lofi_taskq_maxalloc) should be tuned conservatively
* high. If we want to be assured that the underlying device is always busy,
* we must be sure that the number of bytes enqueued when the number of
* enqueued tasks exceeds maxalloc is sufficient to keep the device busy for
* the duration of the sleep time in taskq_ent_alloc(). That is, lofi should
* set maxalloc to be the maximum throughput (in bytes per second) of the
* underlying device divided by the minimum I/O size. We assume a realistic
* maximum throughput of one hundred megabytes per second; we set maxalloc on
* the lofi task queue to be 104857600 divided by DEV_BSIZE.
*/
static int lofi_taskq_maxalloc = 104857600 / DEV_BSIZE;
static int lofi_taskq_nthreads = 4; /* # of taskq threads per device */
uint32_t lofi_max_files = LOFI_MAX_FILES;
const char lofi_crypto_magic[6] = LOFI_CRYPTO_MAGIC;
/*
* To avoid decompressing data in a compressed segment multiple times
* when accessing small parts of a segment's data, we cache and reuse
* the uncompressed segment's data.
*
* A single cached segment is sufficient to avoid lots of duplicate
* segment decompress operations. A small cache size also reduces the
* memory footprint.
*
* lofi_max_comp_cache is the maximum number of decompressed data segments
* cached for each compressed lofi image. It can be set to 0 to disable
* caching.
*/
uint32_t lofi_max_comp_cache = 1;
static int gzip_decompress(void *src, size_t srclen, void *dst,
size_t *destlen, int level);
static int lzma_decompress(void *src, size_t srclen, void *dst,
size_t *dstlen, int level);
lofi_compress_info_t lofi_compress_table[LOFI_COMPRESS_FUNCTIONS] = {
{gzip_decompress, NULL, 6, "gzip"}, /* default */
{gzip_decompress, NULL, 6, "gzip-6"},
{gzip_decompress, NULL, 9, "gzip-9"},
{lzma_decompress, NULL, 0, "lzma"}
};
/*ARGSUSED*/
static void
*SzAlloc(void *p, size_t size)
{
return (kmem_alloc(size, KM_SLEEP));
}
/*ARGSUSED*/
static void
SzFree(void *p, void *address, size_t size)
{
kmem_free(address, size);
}
static ISzAlloc g_Alloc = { SzAlloc, SzFree };
/*
* Free data referenced by the linked list of cached uncompressed
* segments.
*/
static void
lofi_free_comp_cache(struct lofi_state *lsp)
{
struct lofi_comp_cache *lc;
while ((lc = list_remove_head(&lsp->ls_comp_cache)) != NULL) {
kmem_free(lc->lc_data, lsp->ls_uncomp_seg_sz);
kmem_free(lc, sizeof (struct lofi_comp_cache));
lsp->ls_comp_cache_count--;
}
ASSERT(lsp->ls_comp_cache_count == 0);
}
static int
lofi_busy(void)
{
minor_t minor;
/*
* We need to make sure no mappings exist - mod_remove won't
* help because the device isn't open.
*/
mutex_enter(&lofi_lock);
for (minor = 1; minor <= lofi_max_files; minor++) {
if (ddi_get_soft_state(lofi_statep, minor) != NULL) {
mutex_exit(&lofi_lock);
return (EBUSY);
}
}
mutex_exit(&lofi_lock);
return (0);
}
static int
is_opened(struct lofi_state *lsp)
{
ASSERT(mutex_owned(&lofi_lock));
return (lsp->ls_chr_open || lsp->ls_blk_open || lsp->ls_lyr_open_count);
}
static int
mark_opened(struct lofi_state *lsp, int otyp)
{
ASSERT(mutex_owned(&lofi_lock));
switch (otyp) {
case OTYP_CHR:
lsp->ls_chr_open = 1;
break;
case OTYP_BLK:
lsp->ls_blk_open = 1;
break;
case OTYP_LYR:
lsp->ls_lyr_open_count++;
break;
default:
return (-1);
}
return (0);
}
static void
mark_closed(struct lofi_state *lsp, int otyp)
{
ASSERT(mutex_owned(&lofi_lock));
switch (otyp) {
case OTYP_CHR:
lsp->ls_chr_open = 0;
break;
case OTYP_BLK:
lsp->ls_blk_open = 0;
break;
case OTYP_LYR:
lsp->ls_lyr_open_count--;
break;
default:
break;
}
}
static void
lofi_free_crypto(struct lofi_state *lsp)
{
ASSERT(mutex_owned(&lofi_lock));
if (lsp->ls_crypto_enabled) {
/*
* Clean up the crypto state so that it doesn't hang around
* in memory after we are done with it.
*/
bzero(lsp->ls_key.ck_data,
CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
kmem_free(lsp->ls_key.ck_data,
CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
lsp->ls_key.ck_data = NULL;
lsp->ls_key.ck_length = 0;
if (lsp->ls_mech.cm_param != NULL) {
kmem_free(lsp->ls_mech.cm_param,
lsp->ls_mech.cm_param_len);
lsp->ls_mech.cm_param = NULL;
lsp->ls_mech.cm_param_len = 0;
}
if (lsp->ls_iv_mech.cm_param != NULL) {
kmem_free(lsp->ls_iv_mech.cm_param,
lsp->ls_iv_mech.cm_param_len);
lsp->ls_iv_mech.cm_param = NULL;
lsp->ls_iv_mech.cm_param_len = 0;
}
mutex_destroy(&lsp->ls_crypto_lock);
}
}
static void
lofi_free_handle(dev_t dev, minor_t minor, struct lofi_state *lsp,
cred_t *credp)
{
dev_t newdev;
char namebuf[50];
ASSERT(mutex_owned(&lofi_lock));
lofi_free_crypto(lsp);
if (lsp->ls_vp) {
(void) VOP_CLOSE(lsp->ls_vp, lsp->ls_openflag,
1, 0, credp, NULL);
VN_RELE(lsp->ls_vp);
lsp->ls_vp = NULL;
}
newdev = makedevice(getmajor(dev), minor);
(void) ddi_prop_remove(newdev, lofi_dip, SIZE_PROP_NAME);
(void) ddi_prop_remove(newdev, lofi_dip, NBLOCKS_PROP_NAME);
(void) snprintf(namebuf, sizeof (namebuf), "%d", minor);
ddi_remove_minor_node(lofi_dip, namebuf);
(void) snprintf(namebuf, sizeof (namebuf), "%d,raw", minor);
ddi_remove_minor_node(lofi_dip, namebuf);
kmem_free(lsp->ls_filename, lsp->ls_filename_sz);
taskq_destroy(lsp->ls_taskq);
if (lsp->ls_kstat) {
kstat_delete(lsp->ls_kstat);
mutex_destroy(&lsp->ls_kstat_lock);
}
/*
* Free cached decompressed segment data
*/
lofi_free_comp_cache(lsp);
list_destroy(&lsp->ls_comp_cache);
mutex_destroy(&lsp->ls_comp_cache_lock);
if (lsp->ls_uncomp_seg_sz > 0) {
kmem_free(lsp->ls_comp_index_data, lsp->ls_comp_index_data_sz);
lsp->ls_uncomp_seg_sz = 0;
}
mutex_destroy(&lsp->ls_vp_lock);
ddi_soft_state_free(lofi_statep, minor);
}
/*ARGSUSED*/
static int
lofi_open(dev_t *devp, int flag, int otyp, struct cred *credp)
{
minor_t minor;
struct lofi_state *lsp;
mutex_enter(&lofi_lock);
minor = getminor(*devp);
if (minor == 0) {
/* master control device */
/* must be opened exclusively */
if (((flag & FEXCL) != FEXCL) || (otyp != OTYP_CHR)) {
mutex_exit(&lofi_lock);
return (EINVAL);
}
lsp = ddi_get_soft_state(lofi_statep, 0);
if (lsp == NULL) {
mutex_exit(&lofi_lock);
return (ENXIO);
}
if (is_opened(lsp)) {
mutex_exit(&lofi_lock);
return (EBUSY);
}
(void) mark_opened(lsp, OTYP_CHR);
mutex_exit(&lofi_lock);
return (0);
}
/* otherwise, the mapping should already exist */
lsp = ddi_get_soft_state(lofi_statep, minor);
if (lsp == NULL) {
mutex_exit(&lofi_lock);
return (EINVAL);
}
if (lsp->ls_vp == NULL) {
mutex_exit(&lofi_lock);
return (ENXIO);
}
if (mark_opened(lsp, otyp) == -1) {
mutex_exit(&lofi_lock);
return (EINVAL);
}
mutex_exit(&lofi_lock);
return (0);
}
/*ARGSUSED*/
static int
lofi_close(dev_t dev, int flag, int otyp, struct cred *credp)
{
minor_t minor;
struct lofi_state *lsp;
mutex_enter(&lofi_lock);
minor = getminor(dev);
lsp = ddi_get_soft_state(lofi_statep, minor);
if (lsp == NULL) {
mutex_exit(&lofi_lock);
return (EINVAL);
}
mark_closed(lsp, otyp);
/*
* If we forcibly closed the underlying device (li_force), or
* asked for cleanup (li_cleanup), finish up if we're the last
* out of the door.
*/
if (minor != 0 && !is_opened(lsp) &&
(lsp->ls_cleanup || lsp->ls_vp == NULL))
lofi_free_handle(dev, minor, lsp, credp);
mutex_exit(&lofi_lock);
return (0);
}
/*
* Sets the mechanism's initialization vector (IV) if one is needed.
* The IV is computed from the data block number. lsp->ls_mech is
* altered so that:
* lsp->ls_mech.cm_param_len is set to the IV len.
* lsp->ls_mech.cm_param is set to the IV.
*/
static int
lofi_blk_mech(struct lofi_state *lsp, longlong_t lblkno)
{
int ret;
crypto_data_t cdata;
char *iv;
size_t iv_len;
size_t min;
void *data;
size_t datasz;
ASSERT(mutex_owned(&lsp->ls_crypto_lock));
if (lsp == NULL)
return (CRYPTO_DEVICE_ERROR);
/* lsp->ls_mech.cm_param{_len} has already been set for static iv */
if (lsp->ls_iv_type == IVM_NONE) {
return (CRYPTO_SUCCESS);
}
/*
* if kmem already alloced from previous call and it's the same size
* we need now, just recycle it; allocate new kmem only if we have to
*/
if (lsp->ls_mech.cm_param == NULL ||
lsp->ls_mech.cm_param_len != lsp->ls_iv_len) {
iv_len = lsp->ls_iv_len;
iv = kmem_zalloc(iv_len, KM_SLEEP);
} else {
iv_len = lsp->ls_mech.cm_param_len;
iv = lsp->ls_mech.cm_param;
bzero(iv, iv_len);
}
switch (lsp->ls_iv_type) {
case IVM_ENC_BLKNO:
/* iv is not static, lblkno changes each time */
data = &lblkno;
datasz = sizeof (lblkno);
break;
default:
data = 0;
datasz = 0;
break;
}
/*
* write blkno into the iv buffer padded on the left in case
* blkno ever grows bigger than its current longlong_t size
* or a variation other than blkno is used for the iv data
*/
min = MIN(datasz, iv_len);
bcopy(data, iv + (iv_len - min), min);
/* encrypt the data in-place to get the IV */
SETUP_C_DATA(cdata, iv, iv_len);
ret = crypto_encrypt(&lsp->ls_iv_mech, &cdata, &lsp->ls_key,
NULL, NULL, NULL);
if (ret != CRYPTO_SUCCESS) {
cmn_err(CE_WARN, "failed to create iv for block %lld: (0x%x)",
lblkno, ret);
if (lsp->ls_mech.cm_param != iv)
kmem_free(iv, iv_len);
return (ret);
}
/* clean up the iv from the last computation */
if (lsp->ls_mech.cm_param != NULL && lsp->ls_mech.cm_param != iv)
kmem_free(lsp->ls_mech.cm_param, lsp->ls_mech.cm_param_len);
lsp->ls_mech.cm_param_len = iv_len;
lsp->ls_mech.cm_param = iv;
return (CRYPTO_SUCCESS);
}
/*
* Performs encryption and decryption of a chunk of data of size "len",
* one DEV_BSIZE block at a time. "len" is assumed to be a multiple of
* DEV_BSIZE.
*/
static int
lofi_crypto(struct lofi_state *lsp, struct buf *bp, caddr_t plaintext,
caddr_t ciphertext, size_t len, boolean_t op_encrypt)
{
crypto_data_t cdata;
crypto_data_t wdata;
int ret;
longlong_t lblkno = bp->b_lblkno;
mutex_enter(&lsp->ls_crypto_lock);
/*
* though we could encrypt/decrypt entire "len" chunk of data, we need
* to break it into DEV_BSIZE pieces to capture blkno incrementing
*/
SETUP_C_DATA(cdata, plaintext, len);
cdata.cd_length = DEV_BSIZE;
if (ciphertext != NULL) { /* not in-place crypto */
SETUP_C_DATA(wdata, ciphertext, len);
wdata.cd_length = DEV_BSIZE;
}
do {
ret = lofi_blk_mech(lsp, lblkno);
if (ret != CRYPTO_SUCCESS)
continue;
if (op_encrypt) {
ret = crypto_encrypt(&lsp->ls_mech, &cdata,
&lsp->ls_key, NULL,
((ciphertext != NULL) ? &wdata : NULL), NULL);
} else {
ret = crypto_decrypt(&lsp->ls_mech, &cdata,
&lsp->ls_key, NULL,
((ciphertext != NULL) ? &wdata : NULL), NULL);
}
cdata.cd_offset += DEV_BSIZE;
if (ciphertext != NULL)
wdata.cd_offset += DEV_BSIZE;
lblkno++;
} while (ret == CRYPTO_SUCCESS && cdata.cd_offset < len);
mutex_exit(&lsp->ls_crypto_lock);
if (ret != CRYPTO_SUCCESS) {
cmn_err(CE_WARN, "%s failed for block %lld: (0x%x)",
op_encrypt ? "crypto_encrypt()" : "crypto_decrypt()",
lblkno, ret);
}
return (ret);
}
#define RDWR_RAW 1
#define RDWR_BCOPY 2
static int
lofi_rdwr(caddr_t bufaddr, offset_t offset, struct buf *bp,
struct lofi_state *lsp, size_t len, int method, caddr_t bcopy_locn)
{
ssize_t resid;
int isread;
int error;
/*
* Handles reads/writes for both plain and encrypted lofi
* Note: offset is already shifted by lsp->ls_crypto_offset
* when it gets here.
*/
isread = bp->b_flags & B_READ;
if (isread) {
if (method == RDWR_BCOPY) {
/* DO NOT update bp->b_resid for bcopy */
bcopy(bcopy_locn, bufaddr, len);
error = 0;
} else { /* RDWR_RAW */
error = vn_rdwr(UIO_READ, lsp->ls_vp, bufaddr, len,
offset, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred,
&resid);
bp->b_resid = resid;
}
if (lsp->ls_crypto_enabled && error == 0) {
if (lofi_crypto(lsp, bp, bufaddr, NULL, len,
B_FALSE) != CRYPTO_SUCCESS) {
/*
* XXX: original code didn't set residual
* back to len because no error was expected
* from bcopy() if encryption is not enabled
*/
if (method != RDWR_BCOPY)
bp->b_resid = len;
error = EIO;
}
}
return (error);
} else {
void *iobuf = bufaddr;
if (lsp->ls_crypto_enabled) {
/* don't do in-place crypto to keep bufaddr intact */
iobuf = kmem_alloc(len, KM_SLEEP);
if (lofi_crypto(lsp, bp, bufaddr, iobuf, len,
B_TRUE) != CRYPTO_SUCCESS) {
kmem_free(iobuf, len);
if (method != RDWR_BCOPY)
bp->b_resid = len;
return (EIO);
}
}
if (method == RDWR_BCOPY) {
/* DO NOT update bp->b_resid for bcopy */
bcopy(iobuf, bcopy_locn, len);
error = 0;
} else { /* RDWR_RAW */
error = vn_rdwr(UIO_WRITE, lsp->ls_vp, iobuf, len,
offset, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred,
&resid);
bp->b_resid = resid;
}
if (lsp->ls_crypto_enabled) {
kmem_free(iobuf, len);
}
return (error);
}
}
static int
lofi_mapped_rdwr(caddr_t bufaddr, offset_t offset, struct buf *bp,
struct lofi_state *lsp)
{
int error;
offset_t alignedoffset, mapoffset;
size_t xfersize;
int isread;
int smflags;
caddr_t mapaddr;
size_t len;
enum seg_rw srw;
int save_error;
/*
* Note: offset is already shifted by lsp->ls_crypto_offset
* when it gets here.
*/
if (lsp->ls_crypto_enabled)
ASSERT(lsp->ls_vp_comp_size == lsp->ls_vp_size);
/*
* segmap always gives us an 8K (MAXBSIZE) chunk, aligned on
* an 8K boundary, but the buf transfer address may not be
* aligned on more than a 512-byte boundary (we don't enforce
* that even though we could). This matters since the initial
* part of the transfer may not start at offset 0 within the
* segmap'd chunk. So we have to compensate for that with
* 'mapoffset'. Subsequent chunks always start off at the
* beginning, and the last is capped by b_resid
*
* Visually, where "|" represents page map boundaries:
* alignedoffset (mapaddr begins at this segmap boundary)
* | offset (from beginning of file)
* | | len
* v v v
* ===|====X========|====...======|========X====|====
* /-------------...---------------/
* ^ bp->b_bcount/bp->b_resid at start
* /----/--------/----...------/--------/
* ^ ^ ^ ^ ^
* | | | | nth xfersize (<= MAXBSIZE)
* | | 2nd thru n-1st xfersize (= MAXBSIZE)
* | 1st xfersize (<= MAXBSIZE)
* mapoffset (offset into 1st segmap, non-0 1st time, 0 thereafter)
*
* Notes: "alignedoffset" is "offset" rounded down to nearest
* MAXBSIZE boundary. "len" is next page boundary of size
* PAGESIZE after "alignedoffset".
*/
mapoffset = offset & MAXBOFFSET;
alignedoffset = offset - mapoffset;
bp->b_resid = bp->b_bcount;
isread = bp->b_flags & B_READ;
srw = isread ? S_READ : S_WRITE;
do {
xfersize = MIN(lsp->ls_vp_comp_size - offset,
MIN(MAXBSIZE - mapoffset, bp->b_resid));
len = roundup(mapoffset + xfersize, PAGESIZE);
mapaddr = segmap_getmapflt(segkmap, lsp->ls_vp,
alignedoffset, MAXBSIZE, 1, srw);
/*
* Now fault in the pages. This lets us check
* for errors before we reference mapaddr and
* try to resolve the fault in bcopy (which would
* panic instead). And this can easily happen,
* particularly if you've lofi'd a file over NFS
* and someone deletes the file on the server.
*/
error = segmap_fault(kas.a_hat, segkmap, mapaddr,
len, F_SOFTLOCK, srw);
if (error) {
(void) segmap_release(segkmap, mapaddr, 0);
if (FC_CODE(error) == FC_OBJERR)
error = FC_ERRNO(error);
else
error = EIO;
break;
}
/* error may be non-zero for encrypted lofi */
error = lofi_rdwr(bufaddr, 0, bp, lsp, xfersize,
RDWR_BCOPY, mapaddr + mapoffset);
if (error == 0) {
bp->b_resid -= xfersize;
bufaddr += xfersize;
offset += xfersize;
}
smflags = 0;
if (isread) {
smflags |= SM_FREE;
/*
* If we're reading an entire page starting
* at a page boundary, there's a good chance
* we won't need it again. Put it on the
* head of the freelist.
*/
if (mapoffset == 0 && xfersize == MAXBSIZE)
smflags |= SM_DONTNEED;
} else {
if (error == 0) /* write back good pages */
smflags |= SM_WRITE;
}
(void) segmap_fault(kas.a_hat, segkmap, mapaddr,
len, F_SOFTUNLOCK, srw);
save_error = segmap_release(segkmap, mapaddr, smflags);
if (error == 0)
error = save_error;
/* only the first map may start partial */
mapoffset = 0;
alignedoffset += MAXBSIZE;
} while ((error == 0) && (bp->b_resid > 0) &&
(offset < lsp->ls_vp_comp_size));
return (error);
}
/*
* Check if segment seg_index is present in the decompressed segment
* data cache.
*
* Returns a pointer to the decompressed segment data cache entry if
* found, and NULL when decompressed data for this segment is not yet
* cached.
*/
static struct lofi_comp_cache *
lofi_find_comp_data(struct lofi_state *lsp, uint64_t seg_index)
{
struct lofi_comp_cache *lc;
ASSERT(mutex_owned(&lsp->ls_comp_cache_lock));
for (lc = list_head(&lsp->ls_comp_cache); lc != NULL;
lc = list_next(&lsp->ls_comp_cache, lc)) {
if (lc->lc_index == seg_index) {
/*
* Decompressed segment data was found in the
* cache.
*
* The cache uses an LRU replacement strategy;
* move the entry to head of list.
*/
list_remove(&lsp->ls_comp_cache, lc);
list_insert_head(&lsp->ls_comp_cache, lc);
return (lc);
}
}
return (NULL);
}
/*
* Add the data for a decompressed segment at segment index
* seg_index to the cache of the decompressed segments.
*
* Returns a pointer to the cache element structure in case
* the data was added to the cache; returns NULL when the data
* wasn't cached.
*/
static struct lofi_comp_cache *
lofi_add_comp_data(struct lofi_state *lsp, uint64_t seg_index,
uchar_t *data)
{
struct lofi_comp_cache *lc;
ASSERT(mutex_owned(&lsp->ls_comp_cache_lock));
while (lsp->ls_comp_cache_count > lofi_max_comp_cache) {
lc = list_remove_tail(&lsp->ls_comp_cache);
ASSERT(lc != NULL);
kmem_free(lc->lc_data, lsp->ls_uncomp_seg_sz);
kmem_free(lc, sizeof (struct lofi_comp_cache));
lsp->ls_comp_cache_count--;
}
/*
* Do not cache when disabled by tunable variable
*/
if (lofi_max_comp_cache == 0)
return (NULL);
/*
* When the cache has not yet reached the maximum allowed
* number of segments, allocate a new cache element.
* Otherwise the cache is full; reuse the last list element
* (LRU) for caching the decompressed segment data.
*
* The cache element for the new decompressed segment data is
* added to the head of the list.
*/
if (lsp->ls_comp_cache_count < lofi_max_comp_cache) {
lc = kmem_alloc(sizeof (struct lofi_comp_cache), KM_SLEEP);
lc->lc_data = NULL;
list_insert_head(&lsp->ls_comp_cache, lc);
lsp->ls_comp_cache_count++;
} else {
lc = list_remove_tail(&lsp->ls_comp_cache);
if (lc == NULL)
return (NULL);
list_insert_head(&lsp->ls_comp_cache, lc);
}
/*
* Free old uncompressed segment data when reusing a cache
* entry.
*/
if (lc->lc_data != NULL)
kmem_free(lc->lc_data, lsp->ls_uncomp_seg_sz);
lc->lc_data = data;
lc->lc_index = seg_index;
return (lc);
}
/*ARGSUSED*/
static int
gzip_decompress(void *src, size_t srclen, void *dst,
size_t *dstlen, int level)
{
ASSERT(*dstlen >= srclen);
if (z_uncompress(dst, dstlen, src, srclen) != Z_OK)
return (-1);
return (0);
}
#define LZMA_HEADER_SIZE (LZMA_PROPS_SIZE + 8)
/*ARGSUSED*/
static int
lzma_decompress(void *src, size_t srclen, void *dst,
size_t *dstlen, int level)
{
size_t insizepure;
void *actual_src;
ELzmaStatus status;
insizepure = srclen - LZMA_HEADER_SIZE;
actual_src = (void *)((Byte *)src + LZMA_HEADER_SIZE);
if (LzmaDecode((Byte *)dst, (size_t *)dstlen,
(const Byte *)actual_src, &insizepure,
(const Byte *)src, LZMA_PROPS_SIZE, LZMA_FINISH_ANY, &status,
&g_Alloc) != SZ_OK) {
return (-1);
}
return (0);
}
/*
* This is basically what strategy used to be before we found we
* needed task queues.
*/
static void
lofi_strategy_task(void *arg)
{
struct buf *bp = (struct buf *)arg;
int error;
struct lofi_state *lsp;
offset_t offset;
caddr_t bufaddr;
size_t len;
size_t xfersize;
boolean_t bufinited = B_FALSE;
lsp = ddi_get_soft_state(lofi_statep, getminor(bp->b_edev));
if (lsp == NULL) {
error = ENXIO;
goto errout;
}
if (lsp->ls_kstat) {
mutex_enter(lsp->ls_kstat->ks_lock);
kstat_waitq_to_runq(KSTAT_IO_PTR(lsp->ls_kstat));
mutex_exit(lsp->ls_kstat->ks_lock);
}
bp_mapin(bp);
bufaddr = bp->b_un.b_addr;
offset = bp->b_lblkno * DEV_BSIZE; /* offset within file */
if (lsp->ls_crypto_enabled) {
/* encrypted data really begins after crypto header */
offset += lsp->ls_crypto_offset;
}
len = bp->b_bcount;
bufinited = B_TRUE;
if (lsp->ls_vp == NULL || lsp->ls_vp_closereq) {
error = EIO;
goto errout;
}
/*
* We used to always use vn_rdwr here, but we cannot do that because
* we might decide to read or write from the the underlying
* file during this call, which would be a deadlock because
* we have the rw_lock. So instead we page, unless it's not
* mapable or it's a character device or it's an encrypted lofi.
*/
if ((lsp->ls_vp->v_flag & VNOMAP) || (lsp->ls_vp->v_type == VCHR) ||
lsp->ls_crypto_enabled) {
error = lofi_rdwr(bufaddr, offset, bp, lsp, len, RDWR_RAW,
NULL);
} else if (lsp->ls_uncomp_seg_sz == 0) {
error = lofi_mapped_rdwr(bufaddr, offset, bp, lsp);
} else {
uchar_t *compressed_seg = NULL, *cmpbuf;
uchar_t *uncompressed_seg = NULL;
lofi_compress_info_t *li;
size_t oblkcount;
ulong_t seglen;
uint64_t sblkno, eblkno, cmpbytes;
uint64_t uncompressed_seg_index;
struct lofi_comp_cache *lc;
offset_t sblkoff, eblkoff;
u_offset_t salign, ealign;
u_offset_t sdiff;
uint32_t comp_data_sz;
uint64_t i;
/*
* From here on we're dealing primarily with compressed files
*/
ASSERT(!lsp->ls_crypto_enabled);
/*
* Compressed files can only be read from and
* not written to
*/
if (!(bp->b_flags & B_READ)) {
bp->b_resid = bp->b_bcount;
error = EROFS;
goto done;
}
ASSERT(lsp->ls_comp_algorithm_index >= 0);
li = &lofi_compress_table[lsp->ls_comp_algorithm_index];
/*
* Compute starting and ending compressed segment numbers
* We use only bitwise operations avoiding division and
* modulus because we enforce the compression segment size
* to a power of 2
*/
sblkno = offset >> lsp->ls_comp_seg_shift;
sblkoff = offset & (lsp->ls_uncomp_seg_sz - 1);
eblkno = (offset + bp->b_bcount) >> lsp->ls_comp_seg_shift;
eblkoff = (offset + bp->b_bcount) & (lsp->ls_uncomp_seg_sz - 1);
/*
* Check the decompressed segment cache.
*
* The cache is used only when the requested data
* is within a segment. Requests that cross
* segment boundaries bypass the cache.
*/
if (sblkno == eblkno ||
(sblkno + 1 == eblkno && eblkoff == 0)) {
/*
* Request doesn't cross a segment boundary,
* now check the cache.
*/
mutex_enter(&lsp->ls_comp_cache_lock);
lc = lofi_find_comp_data(lsp, sblkno);
if (lc != NULL) {
/*
* We've found the decompressed segment
* data in the cache; reuse it.
*/
bcopy(lc->lc_data + sblkoff, bufaddr,
bp->b_bcount);
mutex_exit(&lsp->ls_comp_cache_lock);
bp->b_resid = 0;
error = 0;
goto done;
}
mutex_exit(&lsp->ls_comp_cache_lock);
}
/*
* Align start offset to block boundary for segmap
*/
salign = lsp->ls_comp_seg_index[sblkno];
sdiff = salign & (DEV_BSIZE - 1);
salign -= sdiff;
if (eblkno >= (lsp->ls_comp_index_sz - 1)) {
/*
* We're dealing with the last segment of
* the compressed file -- the size of this
* segment *may not* be the same as the
* segment size for the file
*/
eblkoff = (offset + bp->b_bcount) &
(lsp->ls_uncomp_last_seg_sz - 1);
ealign = lsp->ls_vp_comp_size;
} else {
ealign = lsp->ls_comp_seg_index[eblkno + 1];
}
/*
* Preserve original request paramaters
*/
oblkcount = bp->b_bcount;
/*
* Assign the calculated parameters
*/
comp_data_sz = ealign - salign;
bp->b_bcount = comp_data_sz;
/*
* Allocate fixed size memory blocks to hold compressed
* segments and one uncompressed segment since we
* uncompress segments one at a time
*/
compressed_seg = kmem_alloc(bp->b_bcount, KM_SLEEP);
uncompressed_seg = kmem_alloc(lsp->ls_uncomp_seg_sz, KM_SLEEP);
/*
* Map in the calculated number of blocks
*/
error = lofi_mapped_rdwr((caddr_t)compressed_seg, salign,
bp, lsp);
bp->b_bcount = oblkcount;
bp->b_resid = oblkcount;
if (error != 0)
goto done;
/*
* We have the compressed blocks, now uncompress them
*/
cmpbuf = compressed_seg + sdiff;
for (i = sblkno; i <= eblkno; i++) {
ASSERT(i < lsp->ls_comp_index_sz - 1);
/*
* The last segment is special in that it is
* most likely not going to be the same
* (uncompressed) size as the other segments.
*/
if (i == (lsp->ls_comp_index_sz - 2)) {
seglen = lsp->ls_uncomp_last_seg_sz;
} else {
seglen = lsp->ls_uncomp_seg_sz;
}
/*
* Each of the segment index entries contains
* the starting block number for that segment.
* The number of compressed bytes in a segment
* is thus the difference between the starting
* block number of this segment and the starting
* block number of the next segment.
*/
cmpbytes = lsp->ls_comp_seg_index[i + 1] -
lsp->ls_comp_seg_index[i];
/*
* The first byte in a compressed segment is a flag
* that indicates whether this segment is compressed
* at all
*/
if (*cmpbuf == UNCOMPRESSED) {
bcopy((cmpbuf + SEGHDR), uncompressed_seg,
(cmpbytes - SEGHDR));
} else {
if (li->l_decompress((cmpbuf + SEGHDR),
(cmpbytes - SEGHDR), uncompressed_seg,
&seglen, li->l_level) != 0) {
error = EIO;
goto done;
}
}
uncompressed_seg_index = i;
/*
* Determine how much uncompressed data we
* have to copy and copy it
*/
xfersize = lsp->ls_uncomp_seg_sz - sblkoff;
if (i == eblkno)
xfersize -= (lsp->ls_uncomp_seg_sz - eblkoff);
bcopy((uncompressed_seg + sblkoff), bufaddr, xfersize);
cmpbuf += cmpbytes;
bufaddr += xfersize;
bp->b_resid -= xfersize;
sblkoff = 0;
if (bp->b_resid == 0)
break;
}
/*
* Add the data for the last decopressed segment to
* the cache.
*
* In case the uncompressed segment data was added to (and
* is referenced by) the cache, make sure we don't free it
* here.
*/
mutex_enter(&lsp->ls_comp_cache_lock);
if ((lc = lofi_add_comp_data(lsp, uncompressed_seg_index,
uncompressed_seg)) != NULL) {
uncompressed_seg = NULL;
}
mutex_exit(&lsp->ls_comp_cache_lock);
done:
if (compressed_seg != NULL)
kmem_free(compressed_seg, comp_data_sz);
if (uncompressed_seg != NULL)
kmem_free(uncompressed_seg, lsp->ls_uncomp_seg_sz);
} /* end of handling compressed files */
errout:
if (bufinited && lsp->ls_kstat) {
size_t n_done = bp->b_bcount - bp->b_resid;
kstat_io_t *kioptr;
mutex_enter(lsp->ls_kstat->ks_lock);
kioptr = KSTAT_IO_PTR(lsp->ls_kstat);
if (bp->b_flags & B_READ) {
kioptr->nread += n_done;
kioptr->reads++;
} else {
kioptr->nwritten += n_done;
kioptr->writes++;
}
kstat_runq_exit(kioptr);
mutex_exit(lsp->ls_kstat->ks_lock);
}
mutex_enter(&lsp->ls_vp_lock);
if (--lsp->ls_vp_iocount == 0)
cv_broadcast(&lsp->ls_vp_cv);
mutex_exit(&lsp->ls_vp_lock);
bioerror(bp, error);
biodone(bp);
}
static int
lofi_strategy(struct buf *bp)
{
struct lofi_state *lsp;
offset_t offset;
/*
* We cannot just do I/O here, because the current thread
* _might_ end up back in here because the underlying filesystem
* wants a buffer, which eventually gets into bio_recycle and
* might call into lofi to write out a delayed-write buffer.
* This is bad if the filesystem above lofi is the same as below.
*
* We could come up with a complex strategy using threads to
* do the I/O asynchronously, or we could use task queues. task
* queues were incredibly easy so they win.
*/
lsp = ddi_get_soft_state(lofi_statep, getminor(bp->b_edev));
if (lsp == NULL) {
bioerror(bp, ENXIO);
biodone(bp);
return (0);
}
mutex_enter(&lsp->ls_vp_lock);
if (lsp->ls_vp == NULL || lsp->ls_vp_closereq) {
bioerror(bp, EIO);
biodone(bp);
mutex_exit(&lsp->ls_vp_lock);
return (0);
}
offset = bp->b_lblkno * DEV_BSIZE; /* offset within file */
if (lsp->ls_crypto_enabled) {
/* encrypted data really begins after crypto header */
offset += lsp->ls_crypto_offset;
}
if (offset == lsp->ls_vp_size) {
/* EOF */
if ((bp->b_flags & B_READ) != 0) {
bp->b_resid = bp->b_bcount;
bioerror(bp, 0);
} else {
/* writes should fail */
bioerror(bp, ENXIO);
}
biodone(bp);
mutex_exit(&lsp->ls_vp_lock);
return (0);
}
if (offset > lsp->ls_vp_size) {
bioerror(bp, ENXIO);
biodone(bp);
mutex_exit(&lsp->ls_vp_lock);
return (0);
}
lsp->ls_vp_iocount++;
mutex_exit(&lsp->ls_vp_lock);
if (lsp->ls_kstat) {
mutex_enter(lsp->ls_kstat->ks_lock);
kstat_waitq_enter(KSTAT_IO_PTR(lsp->ls_kstat));
mutex_exit(lsp->ls_kstat->ks_lock);
}
(void) taskq_dispatch(lsp->ls_taskq, lofi_strategy_task, bp, KM_SLEEP);
return (0);
}
/*ARGSUSED2*/
static int
lofi_read(dev_t dev, struct uio *uio, struct cred *credp)
{
if (getminor(dev) == 0)
return (EINVAL);
UIO_CHECK(uio);
return (physio(lofi_strategy, NULL, dev, B_READ, minphys, uio));
}
/*ARGSUSED2*/
static int
lofi_write(dev_t dev, struct uio *uio, struct cred *credp)
{
if (getminor(dev) == 0)
return (EINVAL);
UIO_CHECK(uio);
return (physio(lofi_strategy, NULL, dev, B_WRITE, minphys, uio));
}
/*ARGSUSED2*/
static int
lofi_aread(dev_t dev, struct aio_req *aio, struct cred *credp)
{
if (getminor(dev) == 0)
return (EINVAL);
UIO_CHECK(aio->aio_uio);
return (aphysio(lofi_strategy, anocancel, dev, B_READ, minphys, aio));
}
/*ARGSUSED2*/
static int
lofi_awrite(dev_t dev, struct aio_req *aio, struct cred *credp)
{
if (getminor(dev) == 0)
return (EINVAL);
UIO_CHECK(aio->aio_uio);
return (aphysio(lofi_strategy, anocancel, dev, B_WRITE, minphys, aio));
}
/*ARGSUSED*/
static int
lofi_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
*result = lofi_dip;
return (DDI_SUCCESS);
case DDI_INFO_DEVT2INSTANCE:
*result = 0;
return (DDI_SUCCESS);
}
return (DDI_FAILURE);
}
static int
lofi_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
int error;
if (cmd != DDI_ATTACH)
return (DDI_FAILURE);
error = ddi_soft_state_zalloc(lofi_statep, 0);
if (error == DDI_FAILURE) {
return (DDI_FAILURE);
}
error = ddi_create_minor_node(dip, LOFI_CTL_NODE, S_IFCHR, 0,
DDI_PSEUDO, NULL);
if (error == DDI_FAILURE) {
ddi_soft_state_free(lofi_statep, 0);
return (DDI_FAILURE);
}
/* driver handles kernel-issued IOCTLs */
if (ddi_prop_create(DDI_DEV_T_NONE, dip, DDI_PROP_CANSLEEP,
DDI_KERNEL_IOCTL, NULL, 0) != DDI_PROP_SUCCESS) {
ddi_remove_minor_node(dip, NULL);
ddi_soft_state_free(lofi_statep, 0);
return (DDI_FAILURE);
}
lofi_dip = dip;
ddi_report_dev(dip);
return (DDI_SUCCESS);
}
static int
lofi_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
if (cmd != DDI_DETACH)
return (DDI_FAILURE);
if (lofi_busy())
return (DDI_FAILURE);
lofi_dip = NULL;
ddi_remove_minor_node(dip, NULL);
ddi_prop_remove_all(dip);
ddi_soft_state_free(lofi_statep, 0);
return (DDI_SUCCESS);
}
/*
* With addition of encryption, be careful that encryption key is wiped before
* kernel memory structures are freed, and also that key is not accidentally
* passed out into userland structures.
*/
static void
free_lofi_ioctl(struct lofi_ioctl *klip)
{
/* Make sure this encryption key doesn't stick around */
bzero(klip->li_key, sizeof (klip->li_key));
kmem_free(klip, sizeof (struct lofi_ioctl));
}
/*
* These two just simplify the rest of the ioctls that need to copyin/out
* the lofi_ioctl structure.
*/
struct lofi_ioctl *
copy_in_lofi_ioctl(const struct lofi_ioctl *ulip, int flag)
{
struct lofi_ioctl *klip;
int error;
klip = kmem_alloc(sizeof (struct lofi_ioctl), KM_SLEEP);
error = ddi_copyin(ulip, klip, sizeof (struct lofi_ioctl), flag);
if (error) {
free_lofi_ioctl(klip);
return (NULL);
}
/* make sure filename is always null-terminated */
klip->li_filename[MAXPATHLEN-1] = '\0';
/* validate minor number */
if (klip->li_minor > lofi_max_files) {
free_lofi_ioctl(klip);
cmn_err(CE_WARN, "attempt to map more than lofi_max_files (%d)",
lofi_max_files);
return (NULL);
}
return (klip);
}
int
copy_out_lofi_ioctl(const struct lofi_ioctl *klip, struct lofi_ioctl *ulip,
int flag)
{
int error;
/*
* NOTE: Do NOT copy the crypto_key_t "back" to userland.
* This ensures that an attacker can't trivially find the
* key for a mapping just by issuing the ioctl.
*
* It can still be found by poking around in kmem with mdb(1),
* but there is no point in making it easy when the info isn't
* of any use in this direction anyway.
*
* Either way we don't actually have the raw key stored in
* a form that we can get it anyway, since we just used it
* to create a ctx template and didn't keep "the original".
*/
error = ddi_copyout(klip, ulip, sizeof (struct lofi_ioctl), flag);
if (error)
return (EFAULT);
return (0);
}
/*
* Return the minor number 'filename' is mapped to, if it is.
*/
static int
file_to_minor(char *filename)
{
minor_t minor;
struct lofi_state *lsp;
ASSERT(mutex_owned(&lofi_lock));
for (minor = 1; minor <= lofi_max_files; minor++) {
lsp = ddi_get_soft_state(lofi_statep, minor);
if (lsp == NULL)
continue;
if (strcmp(lsp->ls_filename, filename) == 0)
return (minor);
}
return (0);
}
/*
* lofiadm does some validation, but since Joe Random (or crashme) could
* do our ioctls, we need to do some validation too.
*/
static int
valid_filename(const char *filename)
{
static char *blkprefix = "/dev/" LOFI_BLOCK_NAME "/";
static char *charprefix = "/dev/" LOFI_CHAR_NAME "/";
/* must be absolute path */
if (filename[0] != '/')
return (0);
/* must not be lofi */
if (strncmp(filename, blkprefix, strlen(blkprefix)) == 0)
return (0);
if (strncmp(filename, charprefix, strlen(charprefix)) == 0)
return (0);
return (1);
}
/*
* Fakes up a disk geometry, and one big partition, based on the size
* of the file. This is needed because we allow newfs'ing the device,
* and newfs will do several disk ioctls to figure out the geometry and
* partition information. It uses that information to determine the parameters
* to pass to mkfs. Geometry is pretty much irrelevant these days, but we
* have to support it.
*/
static void
fake_disk_geometry(struct lofi_state *lsp)
{
u_offset_t dsize = lsp->ls_vp_size - lsp->ls_crypto_offset;
/* dk_geom - see dkio(7I) */
/*
* dkg_ncyl _could_ be set to one here (one big cylinder with gobs
* of sectors), but that breaks programs like fdisk which want to
* partition a disk by cylinder. With one cylinder, you can't create
* an fdisk partition and put pcfs on it for testing (hard to pick
* a number between one and one).
*
* The cheezy floppy test is an attempt to not have too few cylinders
* for a small file, or so many on a big file that you waste space
* for backup superblocks or cylinder group structures.
*/
if (dsize < (2 * 1024 * 1024)) /* floppy? */
lsp->ls_dkg.dkg_ncyl = dsize / (100 * 1024);
else
lsp->ls_dkg.dkg_ncyl = dsize / (300 * 1024);
/* in case file file is < 100k */
if (lsp->ls_dkg.dkg_ncyl == 0)
lsp->ls_dkg.dkg_ncyl = 1;
lsp->ls_dkg.dkg_acyl = 0;
lsp->ls_dkg.dkg_bcyl = 0;
lsp->ls_dkg.dkg_nhead = 1;
lsp->ls_dkg.dkg_obs1 = 0;
lsp->ls_dkg.dkg_intrlv = 0;
lsp->ls_dkg.dkg_obs2 = 0;
lsp->ls_dkg.dkg_obs3 = 0;
lsp->ls_dkg.dkg_apc = 0;
lsp->ls_dkg.dkg_rpm = 7200;
lsp->ls_dkg.dkg_pcyl = lsp->ls_dkg.dkg_ncyl + lsp->ls_dkg.dkg_acyl;
lsp->ls_dkg.dkg_nsect = dsize / (DEV_BSIZE * lsp->ls_dkg.dkg_ncyl);
lsp->ls_dkg.dkg_write_reinstruct = 0;
lsp->ls_dkg.dkg_read_reinstruct = 0;
/* vtoc - see dkio(7I) */
bzero(&lsp->ls_vtoc, sizeof (struct vtoc));
lsp->ls_vtoc.v_sanity = VTOC_SANE;
lsp->ls_vtoc.v_version = V_VERSION;
(void) strncpy(lsp->ls_vtoc.v_volume, LOFI_DRIVER_NAME,
sizeof (lsp->ls_vtoc.v_volume));
lsp->ls_vtoc.v_sectorsz = DEV_BSIZE;
lsp->ls_vtoc.v_nparts = 1;
lsp->ls_vtoc.v_part[0].p_tag = V_UNASSIGNED;
/*
* A compressed file is read-only, other files can
* be read-write
*/
if (lsp->ls_uncomp_seg_sz > 0) {
lsp->ls_vtoc.v_part[0].p_flag = V_UNMNT | V_RONLY;
} else {
lsp->ls_vtoc.v_part[0].p_flag = V_UNMNT;
}
lsp->ls_vtoc.v_part[0].p_start = (daddr_t)0;
/*
* The partition size cannot just be the number of sectors, because
* that might not end on a cylinder boundary. And if that's the case,
* newfs/mkfs will print a scary warning. So just figure the size
* based on the number of cylinders and sectors/cylinder.
*/
lsp->ls_vtoc.v_part[0].p_size = lsp->ls_dkg.dkg_pcyl *
lsp->ls_dkg.dkg_nsect * lsp->ls_dkg.dkg_nhead;
/* dk_cinfo - see dkio(7I) */
bzero(&lsp->ls_ci, sizeof (struct dk_cinfo));
(void) strcpy(lsp->ls_ci.dki_cname, LOFI_DRIVER_NAME);
lsp->ls_ci.dki_ctype = DKC_MD;
lsp->ls_ci.dki_flags = 0;
lsp->ls_ci.dki_cnum = 0;
lsp->ls_ci.dki_addr = 0;
lsp->ls_ci.dki_space = 0;
lsp->ls_ci.dki_prio = 0;
lsp->ls_ci.dki_vec = 0;
(void) strcpy(lsp->ls_ci.dki_dname, LOFI_DRIVER_NAME);
lsp->ls_ci.dki_unit = 0;
lsp->ls_ci.dki_slave = 0;
lsp->ls_ci.dki_partition = 0;
/*
* newfs uses this to set maxcontig. Must not be < 16, or it
* will be 0 when newfs multiplies it by DEV_BSIZE and divides
* it by the block size. Then tunefs doesn't work because
* maxcontig is 0.
*/
lsp->ls_ci.dki_maxtransfer = 16;
}
/*
* map in a compressed file
*
* Read in the header and the index that follows.
*
* The header is as follows -
*
* Signature (name of the compression algorithm)
* Compression segment size (a multiple of 512)
* Number of index entries
* Size of the last block
* The array containing the index entries
*
* The header information is always stored in
* network byte order on disk.
*/
static int
lofi_map_compressed_file(struct lofi_state *lsp, char *buf)
{
uint32_t index_sz, header_len, i;
ssize_t resid;
enum uio_rw rw;
char *tbuf = buf;
int error;
/* The signature has already been read */
tbuf += sizeof (lsp->ls_comp_algorithm);
bcopy(tbuf, &(lsp->ls_uncomp_seg_sz), sizeof (lsp->ls_uncomp_seg_sz));
lsp->ls_uncomp_seg_sz = ntohl(lsp->ls_uncomp_seg_sz);
/*
* The compressed segment size must be a power of 2
*/
if (lsp->ls_uncomp_seg_sz < DEV_BSIZE ||
!ISP2(lsp->ls_uncomp_seg_sz))
return (EINVAL);
for (i = 0; !((lsp->ls_uncomp_seg_sz >> i) & 1); i++)
;
lsp->ls_comp_seg_shift = i;
tbuf += sizeof (lsp->ls_uncomp_seg_sz);
bcopy(tbuf, &(lsp->ls_comp_index_sz), sizeof (lsp->ls_comp_index_sz));
lsp->ls_comp_index_sz = ntohl(lsp->ls_comp_index_sz);
tbuf += sizeof (lsp->ls_comp_index_sz);
bcopy(tbuf, &(lsp->ls_uncomp_last_seg_sz),
sizeof (lsp->ls_uncomp_last_seg_sz));
lsp->ls_uncomp_last_seg_sz = ntohl(lsp->ls_uncomp_last_seg_sz);
/*
* Compute the total size of the uncompressed data
* for use in fake_disk_geometry and other calculations.
* Disk geometry has to be faked with respect to the
* actual uncompressed data size rather than the
* compressed file size.
*/
lsp->ls_vp_size =
(u_offset_t)(lsp->ls_comp_index_sz - 2) * lsp->ls_uncomp_seg_sz
+ lsp->ls_uncomp_last_seg_sz;
/*
* Index size is rounded up to DEV_BSIZE for ease
* of segmapping
*/
index_sz = sizeof (*lsp->ls_comp_seg_index) * lsp->ls_comp_index_sz;
header_len = sizeof (lsp->ls_comp_algorithm) +
sizeof (lsp->ls_uncomp_seg_sz) +
sizeof (lsp->ls_comp_index_sz) +
sizeof (lsp->ls_uncomp_last_seg_sz);
lsp->ls_comp_offbase = header_len + index_sz;
index_sz += header_len;
index_sz = roundup(index_sz, DEV_BSIZE);
lsp->ls_comp_index_data = kmem_alloc(index_sz, KM_SLEEP);
lsp->ls_comp_index_data_sz = index_sz;
/*
* Read in the index -- this has a side-effect
* of reading in the header as well
*/
rw = UIO_READ;
error = vn_rdwr(rw, lsp->ls_vp, lsp->ls_comp_index_data, index_sz,
0, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
if (error != 0)
return (error);
/* Skip the header, this is where the index really begins */
lsp->ls_comp_seg_index =
/*LINTED*/
(uint64_t *)(lsp->ls_comp_index_data + header_len);
/*
* Now recompute offsets in the index to account for
* the header length
*/
for (i = 0; i < lsp->ls_comp_index_sz; i++) {
lsp->ls_comp_seg_index[i] = lsp->ls_comp_offbase +
BE_64(lsp->ls_comp_seg_index[i]);
}
return (error);
}
/*
* Check to see if the passed in signature is a valid
* one. If it is valid, return the index into
* lofi_compress_table.
*
* Return -1 if it is invalid
*/
static int lofi_compress_select(char *signature)
{
int i;
for (i = 0; i < LOFI_COMPRESS_FUNCTIONS; i++) {
if (strcmp(lofi_compress_table[i].l_name, signature) == 0)
return (i);
}
return (-1);
}
/*
* map a file to a minor number. Return the minor number.
*/
static int
lofi_map_file(dev_t dev, struct lofi_ioctl *ulip, int pickminor,
int *rvalp, struct cred *credp, int ioctl_flag)
{
minor_t newminor;
struct lofi_state *lsp;
struct lofi_ioctl *klip;
int error;
struct vnode *vp;
int64_t Nblocks_prop_val;
int64_t Size_prop_val;
int compress_index;
vattr_t vattr;
int flag;
enum vtype v_type;
int zalloced = 0;
dev_t newdev;
char namebuf[50];
char buf[DEV_BSIZE];
char crybuf[DEV_BSIZE];
ssize_t resid;
boolean_t need_vn_close = B_FALSE;
boolean_t keycopied = B_FALSE;
boolean_t need_size_update = B_FALSE;
klip = copy_in_lofi_ioctl(ulip, ioctl_flag);
if (klip == NULL)
return (EFAULT);
mutex_enter(&lofi_lock);
if (!valid_filename(klip->li_filename)) {
error = EINVAL;
goto out;
}
if (file_to_minor(klip->li_filename) != 0) {
error = EBUSY;
goto out;
}
if (pickminor) {
/* Find a free one */
for (newminor = 1; newminor <= lofi_max_files; newminor++)
if (ddi_get_soft_state(lofi_statep, newminor) == NULL)
break;
if (newminor >= lofi_max_files) {
error = EAGAIN;
goto out;
}
} else {
newminor = klip->li_minor;
if (ddi_get_soft_state(lofi_statep, newminor) != NULL) {
error = EEXIST;
goto out;
}
}
/* make sure it's valid */
error = lookupname(klip->li_filename, UIO_SYSSPACE, FOLLOW,
NULLVPP, &vp);
if (error) {
goto out;
}
v_type = vp->v_type;
VN_RELE(vp);
if (!V_ISLOFIABLE(v_type)) {
error = EINVAL;
goto out;
}
flag = FREAD | FWRITE | FOFFMAX | FEXCL;
error = vn_open(klip->li_filename, UIO_SYSSPACE, flag, 0, &vp, 0, 0);
if (error) {
/* try read-only */
flag &= ~FWRITE;
error = vn_open(klip->li_filename, UIO_SYSSPACE, flag, 0,
&vp, 0, 0);
if (error) {
goto out;
}
}
need_vn_close = B_TRUE;
vattr.va_mask = AT_SIZE;
error = VOP_GETATTR(vp, &vattr, 0, credp, NULL);
if (error) {
goto out;
}
/* the file needs to be a multiple of the block size */
if ((vattr.va_size % DEV_BSIZE) != 0) {
error = EINVAL;
goto out;
}
newdev = makedevice(getmajor(dev), newminor);
Size_prop_val = vattr.va_size;
if ((ddi_prop_update_int64(newdev, lofi_dip,
SIZE_PROP_NAME, Size_prop_val)) != DDI_PROP_SUCCESS) {
error = EINVAL;
goto out;
}
Nblocks_prop_val = vattr.va_size / DEV_BSIZE;
if ((ddi_prop_update_int64(newdev, lofi_dip,
NBLOCKS_PROP_NAME, Nblocks_prop_val)) != DDI_PROP_SUCCESS) {
error = EINVAL;
goto propout;
}
error = ddi_soft_state_zalloc(lofi_statep, newminor);
if (error == DDI_FAILURE) {
error = ENOMEM;
goto propout;
}
zalloced = 1;
(void) snprintf(namebuf, sizeof (namebuf), "%d", newminor);
error = ddi_create_minor_node(lofi_dip, namebuf, S_IFBLK, newminor,
DDI_PSEUDO, NULL);
if (error != DDI_SUCCESS) {
error = ENXIO;
goto propout;
}
(void) snprintf(namebuf, sizeof (namebuf), "%d,raw", newminor);
error = ddi_create_minor_node(lofi_dip, namebuf, S_IFCHR, newminor,
DDI_PSEUDO, NULL);
if (error != DDI_SUCCESS) {
/* remove block node */
(void) snprintf(namebuf, sizeof (namebuf), "%d", newminor);
ddi_remove_minor_node(lofi_dip, namebuf);
error = ENXIO;
goto propout;
}
lsp = ddi_get_soft_state(lofi_statep, newminor);
lsp->ls_filename_sz = strlen(klip->li_filename) + 1;
lsp->ls_filename = kmem_alloc(lsp->ls_filename_sz, KM_SLEEP);
(void) snprintf(namebuf, sizeof (namebuf), "%s_taskq_%d",
LOFI_DRIVER_NAME, newminor);
lsp->ls_taskq = taskq_create(namebuf, lofi_taskq_nthreads,
minclsyspri, 1, lofi_taskq_maxalloc, 0);
lsp->ls_kstat = kstat_create(LOFI_DRIVER_NAME, newminor,
NULL, "disk", KSTAT_TYPE_IO, 1, 0);
if (lsp->ls_kstat) {
mutex_init(&lsp->ls_kstat_lock, NULL, MUTEX_DRIVER, NULL);
lsp->ls_kstat->ks_lock = &lsp->ls_kstat_lock;
kstat_install(lsp->ls_kstat);
}
cv_init(&lsp->ls_vp_cv, NULL, CV_DRIVER, NULL);
mutex_init(&lsp->ls_vp_lock, NULL, MUTEX_DRIVER, NULL);
list_create(&lsp->ls_comp_cache, sizeof (struct lofi_comp_cache),
offsetof(struct lofi_comp_cache, lc_list));
mutex_init(&lsp->ls_comp_cache_lock, NULL, MUTEX_DRIVER, NULL);
/*
* save open mode so file can be closed properly and vnode counts
* updated correctly.
*/
lsp->ls_openflag = flag;
/*
* Try to handle stacked lofs vnodes.
*/
if (vp->v_type == VREG) {
if (VOP_REALVP(vp, &lsp->ls_vp, NULL) != 0) {
lsp->ls_vp = vp;
} else {
/*
* Even though vp was obtained via vn_open(), we
* can't call vn_close() on it, since lofs will
* pass the VOP_CLOSE() on down to the realvp
* (which we are about to use). Hence we merely
* drop the reference to the lofs vnode and hold
* the realvp so things behave as if we've
* opened the realvp without any interaction
* with lofs.
*/
VN_HOLD(lsp->ls_vp);
VN_RELE(vp);
}
} else {
lsp->ls_vp = vp;
}
lsp->ls_vp_size = vattr.va_size;
(void) strcpy(lsp->ls_filename, klip->li_filename);
if (rvalp)
*rvalp = (int)newminor;
klip->li_minor = newminor;
/*
* Initialize crypto details for encrypted lofi
*/
if (klip->li_crypto_enabled) {
int ret;
mutex_init(&lsp->ls_crypto_lock, NULL, MUTEX_DRIVER, NULL);
lsp->ls_mech.cm_type = crypto_mech2id(klip->li_cipher);
if (lsp->ls_mech.cm_type == CRYPTO_MECH_INVALID) {
cmn_err(CE_WARN, "invalid cipher %s requested for %s",
klip->li_cipher, lsp->ls_filename);
error = EINVAL;
goto propout;
}
/* this is just initialization here */
lsp->ls_mech.cm_param = NULL;
lsp->ls_mech.cm_param_len = 0;
lsp->ls_iv_type = klip->li_iv_type;
lsp->ls_iv_mech.cm_type = crypto_mech2id(klip->li_iv_cipher);
if (lsp->ls_iv_mech.cm_type == CRYPTO_MECH_INVALID) {
cmn_err(CE_WARN, "invalid iv cipher %s requested"
" for %s", klip->li_iv_cipher, lsp->ls_filename);
error = EINVAL;
goto propout;
}
/* iv mech must itself take a null iv */
lsp->ls_iv_mech.cm_param = NULL;
lsp->ls_iv_mech.cm_param_len = 0;
lsp->ls_iv_len = klip->li_iv_len;
/*
* Create ctx using li_cipher & the raw li_key after checking
* that it isn't a weak key.
*/
lsp->ls_key.ck_format = CRYPTO_KEY_RAW;
lsp->ls_key.ck_length = klip->li_key_len;
lsp->ls_key.ck_data = kmem_alloc(
CRYPTO_BITS2BYTES(lsp->ls_key.ck_length), KM_SLEEP);
bcopy(klip->li_key, lsp->ls_key.ck_data,
CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
keycopied = B_TRUE;
ret = crypto_key_check(&lsp->ls_mech, &lsp->ls_key);
if (ret != CRYPTO_SUCCESS) {
error = EINVAL;
cmn_err(CE_WARN, "weak key check failed for cipher "
"%s on file %s (0x%x)", klip->li_cipher,
lsp->ls_filename, ret);
goto propout;
}
}
lsp->ls_crypto_enabled = klip->li_crypto_enabled;
/*
* Read the file signature to check if it is compressed or encrypted.
* Crypto signature is in a different location; both areas should
* read to keep compression and encryption mutually exclusive.
*/
if (lsp->ls_crypto_enabled) {
error = vn_rdwr(UIO_READ, lsp->ls_vp, crybuf, DEV_BSIZE,
CRYOFF, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
if (error != 0)
goto propout;
}
error = vn_rdwr(UIO_READ, lsp->ls_vp, buf, DEV_BSIZE, 0, UIO_SYSSPACE,
0, RLIM64_INFINITY, kcred, &resid);
if (error != 0)
goto propout;
/* initialize these variables for all lofi files */
lsp->ls_uncomp_seg_sz = 0;
lsp->ls_vp_comp_size = lsp->ls_vp_size;
lsp->ls_comp_algorithm[0] = '\0';
/* encrypted lofi reads/writes shifted by crypto metadata size */
lsp->ls_crypto_offset = 0;
/* this is a compressed lofi */
if ((compress_index = lofi_compress_select(buf)) != -1) {
/* compression and encryption are mutually exclusive */
if (klip->li_crypto_enabled) {
error = ENOTSUP;
goto propout;
}
/* initialize compression info for compressed lofi */
lsp->ls_comp_algorithm_index = compress_index;
(void) strlcpy(lsp->ls_comp_algorithm,
lofi_compress_table[compress_index].l_name,
sizeof (lsp->ls_comp_algorithm));
error = lofi_map_compressed_file(lsp, buf);
if (error != 0)
goto propout;
need_size_update = B_TRUE;
/* this is an encrypted lofi */
} else if (strncmp(crybuf, lofi_crypto_magic,
sizeof (lofi_crypto_magic)) == 0) {
char *marker = crybuf;
/*
* This is the case where the header in the lofi image is
* already initialized to indicate it is encrypted.
* There is another case (see below) where encryption is
* requested but the lofi image has never been used yet,
* so the header needs to be written with encryption magic.
*/
/* indicate this must be an encrypted lofi due to magic */
klip->li_crypto_enabled = B_TRUE;
/*
* The encryption header information is laid out this way:
* 6 bytes: hex "CFLOFI"
* 2 bytes: version = 0 ... for now
* 96 bytes: reserved1 (not implemented yet)
* 4 bytes: data_sector = 2 ... for now
* more... not implemented yet
*/
/* copy the magic */
bcopy(marker, lsp->ls_crypto.magic,
sizeof (lsp->ls_crypto.magic));
marker += sizeof (lsp->ls_crypto.magic);
/* read the encryption version number */
bcopy(marker, &(lsp->ls_crypto.version),
sizeof (lsp->ls_crypto.version));
lsp->ls_crypto.version = ntohs(lsp->ls_crypto.version);
marker += sizeof (lsp->ls_crypto.version);
/* read a chunk of reserved data */
bcopy(marker, lsp->ls_crypto.reserved1,
sizeof (lsp->ls_crypto.reserved1));
marker += sizeof (lsp->ls_crypto.reserved1);
/* read block number where encrypted data begins */
bcopy(marker, &(lsp->ls_crypto.data_sector),
sizeof (lsp->ls_crypto.data_sector));
lsp->ls_crypto.data_sector = ntohl(lsp->ls_crypto.data_sector);
marker += sizeof (lsp->ls_crypto.data_sector);
/* and ignore the rest until it is implemented */
lsp->ls_crypto_offset = lsp->ls_crypto.data_sector * DEV_BSIZE;
need_size_update = B_TRUE;
/* neither compressed nor encrypted, BUT could be new encrypted lofi */
} else if (klip->li_crypto_enabled) {
/*
* This is the case where encryption was requested but the
* appears to be entirely blank where the encryption header
* would have been in the lofi image. If it is blank,
* assume it is a brand new lofi image and initialize the
* header area with encryption magic and current version
* header data. If it is not blank, that's an error.
*/
int i;
char *marker;
struct crypto_meta chead;
for (i = 0; i < sizeof (struct crypto_meta); i++)
if (crybuf[i] != '\0')
break;
if (i != sizeof (struct crypto_meta)) {
error = EINVAL;
goto propout;
}
/* nothing there, initialize as encrypted lofi */
marker = crybuf;
bcopy(lofi_crypto_magic, marker, sizeof (lofi_crypto_magic));
marker += sizeof (lofi_crypto_magic);
chead.version = htons(LOFI_CRYPTO_VERSION);
bcopy(&(chead.version), marker, sizeof (chead.version));
marker += sizeof (chead.version);
marker += sizeof (chead.reserved1);
chead.data_sector = htonl(LOFI_CRYPTO_DATA_SECTOR);
bcopy(&(chead.data_sector), marker, sizeof (chead.data_sector));
/* write the header */
error = vn_rdwr(UIO_WRITE, lsp->ls_vp, crybuf, DEV_BSIZE,
CRYOFF, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
if (error != 0)
goto propout;
/* fix things up so it looks like we read this info */
bcopy(lofi_crypto_magic, lsp->ls_crypto.magic,
sizeof (lofi_crypto_magic));
lsp->ls_crypto.version = LOFI_CRYPTO_VERSION;
lsp->ls_crypto.data_sector = LOFI_CRYPTO_DATA_SECTOR;
lsp->ls_crypto_offset = lsp->ls_crypto.data_sector * DEV_BSIZE;
need_size_update = B_TRUE;
}
/*
* Either lsp->ls_vp_size or lsp->ls_crypto_offset changed;
* for encrypted lofi, advertise that it is somewhat shorter
* due to embedded crypto metadata section
*/
if (need_size_update) {
/* update DDI properties */
Size_prop_val = lsp->ls_vp_size - lsp->ls_crypto_offset;
if ((ddi_prop_update_int64(newdev, lofi_dip, SIZE_PROP_NAME,
Size_prop_val)) != DDI_PROP_SUCCESS) {
error = EINVAL;
goto propout;
}
Nblocks_prop_val =
(lsp->ls_vp_size - lsp->ls_crypto_offset) / DEV_BSIZE;
if ((ddi_prop_update_int64(newdev, lofi_dip, NBLOCKS_PROP_NAME,
Nblocks_prop_val)) != DDI_PROP_SUCCESS) {
error = EINVAL;
goto propout;
}
}
fake_disk_geometry(lsp);
mutex_exit(&lofi_lock);
(void) copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
free_lofi_ioctl(klip);
return (0);
propout:
if (keycopied) {
bzero(lsp->ls_key.ck_data,
CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
kmem_free(lsp->ls_key.ck_data,
CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
lsp->ls_key.ck_data = NULL;
lsp->ls_key.ck_length = 0;
}
if (zalloced)
ddi_soft_state_free(lofi_statep, newminor);
(void) ddi_prop_remove(newdev, lofi_dip, SIZE_PROP_NAME);
(void) ddi_prop_remove(newdev, lofi_dip, NBLOCKS_PROP_NAME);
out:
if (need_vn_close) {
(void) VOP_CLOSE(vp, flag, 1, 0, credp, NULL);
VN_RELE(vp);
}
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (error);
}
/*
* unmap a file.
*/
static int
lofi_unmap_file(dev_t dev, struct lofi_ioctl *ulip, int byfilename,
struct cred *credp, int ioctl_flag)
{
struct lofi_state *lsp;
struct lofi_ioctl *klip;
minor_t minor;
klip = copy_in_lofi_ioctl(ulip, ioctl_flag);
if (klip == NULL)
return (EFAULT);
mutex_enter(&lofi_lock);
if (byfilename) {
minor = file_to_minor(klip->li_filename);
} else {
minor = klip->li_minor;
}
if (minor == 0) {
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (ENXIO);
}
lsp = ddi_get_soft_state(lofi_statep, minor);
if (lsp == NULL || lsp->ls_vp == NULL) {
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (ENXIO);
}
/*
* If it's still held open, we'll do one of three things:
*
* If no flag is set, just return EBUSY.
*
* If the 'cleanup' flag is set, unmap and remove the device when
* the last user finishes.
*
* If the 'force' flag is set, then we forcibly close the underlying
* file. Subsequent operations will fail, and the DKIOCSTATE ioctl
* will return DKIO_DEV_GONE. When the device is last closed, the
* device will be cleaned up appropriately.
*
* This is complicated by the fact that we may have outstanding
* dispatched I/Os. Rather than having a single mutex to serialize all
* I/O, we keep a count of the number of outstanding I/O requests
* (ls_vp_iocount), as well as a flag to indicate that no new I/Os
* should be dispatched (ls_vp_closereq).
*
* We set the flag, wait for the number of outstanding I/Os to reach 0,
* and then close the underlying vnode.
*/
if (is_opened(lsp)) {
if (klip->li_force) {
mutex_enter(&lsp->ls_vp_lock);
lsp->ls_vp_closereq = B_TRUE;
/* wake up any threads waiting on dkiocstate */
cv_broadcast(&lsp->ls_vp_cv);
while (lsp->ls_vp_iocount > 0)
cv_wait(&lsp->ls_vp_cv, &lsp->ls_vp_lock);
mutex_exit(&lsp->ls_vp_lock);
lofi_free_handle(dev, minor, lsp, credp);
klip->li_minor = minor;
mutex_exit(&lofi_lock);
(void) copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
free_lofi_ioctl(klip);
return (0);
} else if (klip->li_cleanup) {
lsp->ls_cleanup = 1;
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (0);
}
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (EBUSY);
}
lofi_free_handle(dev, minor, lsp, credp);
klip->li_minor = minor;
mutex_exit(&lofi_lock);
(void) copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
free_lofi_ioctl(klip);
return (0);
}
/*
* get the filename given the minor number, or the minor number given
* the name.
*/
/*ARGSUSED*/
static int
lofi_get_info(dev_t dev, struct lofi_ioctl *ulip, int which,
struct cred *credp, int ioctl_flag)
{
struct lofi_state *lsp;
struct lofi_ioctl *klip;
int error;
minor_t minor;
klip = copy_in_lofi_ioctl(ulip, ioctl_flag);
if (klip == NULL)
return (EFAULT);
switch (which) {
case LOFI_GET_FILENAME:
minor = klip->li_minor;
if (minor == 0) {
free_lofi_ioctl(klip);
return (EINVAL);
}
mutex_enter(&lofi_lock);
lsp = ddi_get_soft_state(lofi_statep, minor);
if (lsp == NULL) {
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (ENXIO);
}
(void) strcpy(klip->li_filename, lsp->ls_filename);
(void) strlcpy(klip->li_algorithm, lsp->ls_comp_algorithm,
sizeof (klip->li_algorithm));
klip->li_crypto_enabled = lsp->ls_crypto_enabled;
mutex_exit(&lofi_lock);
error = copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
free_lofi_ioctl(klip);
return (error);
case LOFI_GET_MINOR:
mutex_enter(&lofi_lock);
klip->li_minor = file_to_minor(klip->li_filename);
/* caller should not depend on klip->li_crypto_enabled here */
mutex_exit(&lofi_lock);
if (klip->li_minor == 0) {
free_lofi_ioctl(klip);
return (ENOENT);
}
error = copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
free_lofi_ioctl(klip);
return (error);
case LOFI_CHECK_COMPRESSED:
mutex_enter(&lofi_lock);
klip->li_minor = file_to_minor(klip->li_filename);
mutex_exit(&lofi_lock);
if (klip->li_minor == 0) {
free_lofi_ioctl(klip);
return (ENOENT);
}
mutex_enter(&lofi_lock);
lsp = ddi_get_soft_state(lofi_statep, klip->li_minor);
if (lsp == NULL) {
mutex_exit(&lofi_lock);
free_lofi_ioctl(klip);
return (ENXIO);
}
ASSERT(strcmp(klip->li_filename, lsp->ls_filename) == 0);
(void) strlcpy(klip->li_algorithm, lsp->ls_comp_algorithm,
sizeof (klip->li_algorithm));
mutex_exit(&lofi_lock);
error = copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
free_lofi_ioctl(klip);
return (error);
default:
free_lofi_ioctl(klip);
return (EINVAL);
}
}
static int
lofi_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *credp,
int *rvalp)
{
int error;
enum dkio_state dkstate;
struct lofi_state *lsp;
minor_t minor;
minor = getminor(dev);
/* lofi ioctls only apply to the master device */
if (minor == 0) {
struct lofi_ioctl *lip = (struct lofi_ioctl *)arg;
/*
* the query command only need read-access - i.e., normal
* users are allowed to do those on the ctl device as
* long as they can open it read-only.
*/
switch (cmd) {
case LOFI_MAP_FILE:
if ((flag & FWRITE) == 0)
return (EPERM);
return (lofi_map_file(dev, lip, 1, rvalp, credp, flag));
case LOFI_MAP_FILE_MINOR:
if ((flag & FWRITE) == 0)
return (EPERM);
return (lofi_map_file(dev, lip, 0, rvalp, credp, flag));
case LOFI_UNMAP_FILE:
if ((flag & FWRITE) == 0)
return (EPERM);
return (lofi_unmap_file(dev, lip, 1, credp, flag));
case LOFI_UNMAP_FILE_MINOR:
if ((flag & FWRITE) == 0)
return (EPERM);
return (lofi_unmap_file(dev, lip, 0, credp, flag));
case LOFI_GET_FILENAME:
return (lofi_get_info(dev, lip, LOFI_GET_FILENAME,
credp, flag));
case LOFI_GET_MINOR:
return (lofi_get_info(dev, lip, LOFI_GET_MINOR,
credp, flag));
case LOFI_GET_MAXMINOR:
error = ddi_copyout(&lofi_max_files, &lip->li_minor,
sizeof (lofi_max_files), flag);
if (error)
return (EFAULT);
return (0);
case LOFI_CHECK_COMPRESSED:
return (lofi_get_info(dev, lip, LOFI_CHECK_COMPRESSED,
credp, flag));
default:
break;
}
}
mutex_enter(&lofi_lock);
lsp = ddi_get_soft_state(lofi_statep, minor);
if (lsp == NULL || lsp->ls_vp_closereq) {
mutex_exit(&lofi_lock);
return (ENXIO);
}
mutex_exit(&lofi_lock);
/*
* We explicitly allow DKIOCSTATE, but all other ioctls should fail with
* EIO as if the device was no longer present.
*/
if (lsp->ls_vp == NULL && cmd != DKIOCSTATE)
return (EIO);
/* these are for faking out utilities like newfs */
switch (cmd) {
case DKIOCGVTOC:
switch (ddi_model_convert_from(flag & FMODELS)) {
case DDI_MODEL_ILP32: {
struct vtoc32 vtoc32;
vtoctovtoc32(lsp->ls_vtoc, vtoc32);
if (ddi_copyout(&vtoc32, (void *)arg,
sizeof (struct vtoc32), flag))
return (EFAULT);
break;
}
case DDI_MODEL_NONE:
if (ddi_copyout(&lsp->ls_vtoc, (void *)arg,
sizeof (struct vtoc), flag))
return (EFAULT);
break;
}
return (0);
case DKIOCINFO:
error = ddi_copyout(&lsp->ls_ci, (void *)arg,
sizeof (struct dk_cinfo), flag);
if (error)
return (EFAULT);
return (0);
case DKIOCG_VIRTGEOM:
case DKIOCG_PHYGEOM:
case DKIOCGGEOM:
error = ddi_copyout(&lsp->ls_dkg, (void *)arg,
sizeof (struct dk_geom), flag);
if (error)
return (EFAULT);
return (0);
case DKIOCSTATE:
/*
* Normally, lofi devices are always in the INSERTED state. If
* a device is forcefully unmapped, then the device transitions
* to the DKIO_DEV_GONE state.
*/
if (ddi_copyin((void *)arg, &dkstate, sizeof (dkstate),
flag) != 0)
return (EFAULT);
mutex_enter(&lsp->ls_vp_lock);
lsp->ls_vp_iocount++;
while (((dkstate == DKIO_INSERTED && lsp->ls_vp != NULL) ||
(dkstate == DKIO_DEV_GONE && lsp->ls_vp == NULL)) &&
!lsp->ls_vp_closereq) {
/*
* By virtue of having the device open, we know that
* 'lsp' will remain valid when we return.
*/
if (!cv_wait_sig(&lsp->ls_vp_cv,
&lsp->ls_vp_lock)) {
lsp->ls_vp_iocount--;
cv_broadcast(&lsp->ls_vp_cv);
mutex_exit(&lsp->ls_vp_lock);
return (EINTR);
}
}
dkstate = (!lsp->ls_vp_closereq && lsp->ls_vp != NULL ?
DKIO_INSERTED : DKIO_DEV_GONE);
lsp->ls_vp_iocount--;
cv_broadcast(&lsp->ls_vp_cv);
mutex_exit(&lsp->ls_vp_lock);
if (ddi_copyout(&dkstate, (void *)arg,
sizeof (dkstate), flag) != 0)
return (EFAULT);
return (0);
default:
return (ENOTTY);
}
}
static struct cb_ops lofi_cb_ops = {
lofi_open, /* open */
lofi_close, /* close */
lofi_strategy, /* strategy */
nodev, /* print */
nodev, /* dump */
lofi_read, /* read */
lofi_write, /* write */
lofi_ioctl, /* ioctl */
nodev, /* devmap */
nodev, /* mmap */
nodev, /* segmap */
nochpoll, /* poll */
ddi_prop_op, /* prop_op */
0, /* streamtab */
D_64BIT | D_NEW | D_MP, /* Driver compatibility flag */
CB_REV,
lofi_aread,
lofi_awrite
};
static struct dev_ops lofi_ops = {
DEVO_REV, /* devo_rev, */
0, /* refcnt */
lofi_info, /* info */
nulldev, /* identify */
nulldev, /* probe */
lofi_attach, /* attach */
lofi_detach, /* detach */
nodev, /* reset */
&lofi_cb_ops, /* driver operations */
NULL, /* no bus operations */
NULL, /* power */
ddi_quiesce_not_needed, /* quiesce */
};
static struct modldrv modldrv = {
&mod_driverops,
"loopback file driver",
&lofi_ops,
};
static struct modlinkage modlinkage = {
MODREV_1,
&modldrv,
NULL
};
int
_init(void)
{
int error;
error = ddi_soft_state_init(&lofi_statep,
sizeof (struct lofi_state), 0);
if (error)
return (error);
mutex_init(&lofi_lock, NULL, MUTEX_DRIVER, NULL);
error = mod_install(&modlinkage);
if (error) {
mutex_destroy(&lofi_lock);
ddi_soft_state_fini(&lofi_statep);
}
return (error);
}
int
_fini(void)
{
int error;
if (lofi_busy())
return (EBUSY);
error = mod_remove(&modlinkage);
if (error)
return (error);
mutex_destroy(&lofi_lock);
ddi_soft_state_fini(&lofi_statep);
return (error);
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}