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minix/drivers/filter/driver.c
David van Moolenbroek 7685e98304 typo
2010-03-16 16:21:28 +00:00

1001 lines
26 KiB
C
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/* Filter driver - lowest layer - disk driver management */
#include "inc.h"
/* Drivers. */
static struct {
char *label;
int minor;
endpoint_t endpt;
int problem; /* one of BD_* */
int error; /* one of E*, only relevant if problem>0 */
int retries;
int kills;
} driver[2];
/* State variables. */
static endpoint_t self_ep;
static asynmsg_t amsgtable[2];
static int size_known = 0;
static u64_t disk_size;
static int problem_stats[BD_LAST] = { 0 };
/*===========================================================================*
* driver_open *
*===========================================================================*/
static int driver_open(int which)
{
/* Perform an open or close operation on the driver. This is
* unfinished code: we should never be doing a blocking sendrec() to
* the driver.
*/
message msg;
cp_grant_id_t gid;
struct partition part;
sector_t sectors;
int r;
msg.m_type = DEV_OPEN;
msg.DEVICE = driver[which].minor;
msg.IO_ENDPT = self_ep;
r = sendrec(driver[which].endpt, &msg);
if (r != OK) {
/* Should we restart the driver now? */
printf("Filter: driver_open: sendrec returned %d\n", r);
return RET_REDO;
}
if(msg.m_type != TASK_REPLY || msg.REP_STATUS != OK) {
printf("Filter: driver_open: sendrec returned %d, %d\n",
msg.m_type, msg.REP_STATUS);
return RET_REDO;
}
/* Take the opportunity to retrieve the hard disk size. */
gid = cpf_grant_direct(driver[which].endpt,
(vir_bytes) &part, sizeof(part), CPF_WRITE);
if(!GRANT_VALID(gid))
panic("invalid grant: %d", gid);
msg.m_type = DEV_IOCTL_S;
msg.REQUEST = DIOCGETP;
msg.DEVICE = driver[which].minor;
msg.IO_ENDPT = self_ep;
msg.IO_GRANT = (char *) gid;
r = sendrec(driver[which].endpt, &msg);
cpf_revoke(gid);
if (r != OK || msg.m_type != TASK_REPLY || msg.REP_STATUS != OK) {
/* Not sure what to do here, either. */
printf("Filter: ioctl(DIOCGETP) returned (%d, %d)\n",
r, msg.m_type);
return RET_REDO;
}
if(!size_known) {
disk_size = part.size;
size_known = 1;
sectors = div64u(disk_size, SECTOR_SIZE);
if(cmp64(mul64u(sectors, SECTOR_SIZE), disk_size)) {
printf("Filter: partition too large\n");
return RET_REDO;
}
#if DEBUG
printf("Filter: partition size: 0x%s / %lu sectors\n",
print64(disk_size), sectors);
#endif
} else {
if(cmp64(disk_size, part.size)) {
printf("Filter: partition size mismatch (%s != %s)\n",
print64(part.size), print64(disk_size));
return RET_REDO;
}
}
return OK;
}
/*===========================================================================*
* driver_close *
*===========================================================================*/
static int driver_close(int which)
{
message msg;
int r;
msg.m_type = DEV_CLOSE;
msg.DEVICE = driver[which].minor;
msg.IO_ENDPT = self_ep;
r = sendrec(driver[which].endpt, &msg);
if (r != OK) {
/* Should we restart the driver now? */
printf("Filter: driver_close: sendrec returned %d\n", r);
return RET_REDO;
}
if(msg.m_type != TASK_REPLY || msg.REP_STATUS != OK) {
printf("Filter: driver_close: sendrec returned %d, %d\n",
msg.m_type, msg.REP_STATUS);
return RET_REDO;
}
return OK;
}
/*===========================================================================*
* driver_init *
*===========================================================================*/
void driver_init(void)
{
/* Initialize the driver layer. */
int r;
self_ep = getprocnr();
memset(driver, 0, sizeof(driver));
/* Endpoints unknown. */
driver[DRIVER_MAIN].endpt = NONE;
driver[DRIVER_BACKUP].endpt = NONE;
/* Get disk driver's and this proc's endpoint. */
driver[DRIVER_MAIN].label = MAIN_LABEL;
driver[DRIVER_MAIN].minor = MAIN_MINOR;
r = ds_retrieve_label_num(driver[DRIVER_MAIN].label,
(u32_t *) &driver[DRIVER_MAIN].endpt);
if (r != OK) {
printf("Filter: failed to get main disk driver's endpoint: "
"%d\n", r);
bad_driver(DRIVER_MAIN, BD_DEAD, EFAULT);
check_driver(DRIVER_MAIN);
}
else if (driver_open(DRIVER_MAIN) != OK) {
panic("unhandled driver_open failure");
}
if(USE_MIRROR) {
driver[DRIVER_BACKUP].label = BACKUP_LABEL;
driver[DRIVER_BACKUP].minor = BACKUP_MINOR;
if(!strcmp(driver[DRIVER_MAIN].label,
driver[DRIVER_BACKUP].label)) {
panic("same driver: not tested");
}
r = ds_retrieve_label_num(driver[DRIVER_BACKUP].label,
(u32_t *) &driver[DRIVER_BACKUP].endpt);
if (r != OK) {
printf("Filter: failed to get backup disk driver's "
"endpoint: %d\n", r);
bad_driver(DRIVER_BACKUP, BD_DEAD, EFAULT);
check_driver(DRIVER_BACKUP);
}
else if (driver_open(DRIVER_BACKUP) != OK) {
panic("unhandled driver_open failure");
}
}
}
/*===========================================================================*
* driver_shutdown *
*===========================================================================*/
void driver_shutdown(void)
{
/* Clean up. */
#if DEBUG
printf("Filter: %u driver deaths, %u protocol errors, "
"%u data errors\n", problem_stats[BD_DEAD],
problem_stats[BD_PROTO], problem_stats[BD_DATA]);
#endif
if(driver_close(DRIVER_MAIN) != OK)
printf("Filter: DEV_CLOSE failed on shutdown (1)\n");
if(USE_MIRROR)
if(driver_close(DRIVER_BACKUP) != OK)
printf("Filter: DEV_CLOSE failed on shutdown (2)\n");
}
/*===========================================================================*
* get_raw_size *
*===========================================================================*/
u64_t get_raw_size(void)
{
/* Return the size of the raw disks as used by the filter driver.
*/
return disk_size;
}
/*===========================================================================*
* reset_kills *
*===========================================================================*/
void reset_kills(void)
{
/* Reset kill and retry statistics. */
driver[DRIVER_MAIN].kills = 0;
driver[DRIVER_MAIN].retries = 0;
driver[DRIVER_BACKUP].kills = 0;
driver[DRIVER_BACKUP].retries = 0;
}
/*===========================================================================*
* bad_driver *
*===========================================================================*/
int bad_driver(int which, int type, int error)
{
/* A disk driver has died or produced an error. Mark it so that we can
* deal with it later, and return RET_REDO to indicate that the
* current operation is to be retried. Also store an error code to
* return to the user if the situation is unrecoverable.
*/
driver[which].problem = type;
driver[which].error = error;
return RET_REDO;
}
/*===========================================================================*
* new_driver_ep *
*===========================================================================*/
static int new_driver_ep(int which)
{
/* See if a new driver instance has already been started for the given
* driver, by retrieving its entry from DS.
*/
int r;
endpoint_t endpt;
r = ds_retrieve_label_num(driver[which].label, (u32_t *) &endpt);
if (r != OK) {
printf("Filter: DS query for %s failed\n",
driver[which].label);
return 0;
}
if (endpt == driver[which].endpt) {
#if DEBUG
printf("Filter: same endpoint for %s\n", driver[which].label);
#endif
return 0;
}
#if DEBUG
printf("Filter: new enpdoint for %s: %d -> %d\n", driver[which].label,
driver[which].endpt, endpt);
#endif
driver[which].endpt = endpt;
return 1;
}
/*===========================================================================*
* check_problem *
*===========================================================================*/
static int check_problem(int which, int problem, int retries, int *tell_rs)
{
/* A problem has occurred with a driver. Update statistics, and decide
* what to do. If EAGAIN is returned, the driver should be restarted;
* any other result will be passed up.
*/
#if DEBUG
printf("Filter: check_problem processing driver %d, problem %d\n",
which, problem);
#endif
problem_stats[problem]++;
if(new_driver_ep(which)) {
#if DEBUG
printf("Filter: check_problem: noticed a new driver\n");
#endif
if(driver_open(which) == OK) {
#if DEBUG2
printf("Filter: open OK -> no recovery\n");
#endif
return OK;
} else {
#if DEBUG2
printf("Filter: open not OK -> recovery\n");
#endif
problem = BD_PROTO;
problem_stats[problem]++;
}
}
/* If the driver has died, we always need to restart it. If it has
* been giving problems, we first retry the request, up to N times,
* after which we kill and restart the driver. We restart the driver
* up to M times, after which we remove the driver from the mirror
* configuration. If we are not set up to do mirroring, we can only
* do one thing, and that is continue to limp along with the bad
* driver..
*/
switch(problem) {
case BD_PROTO:
case BD_DATA:
driver[which].retries++;
#if DEBUG
printf("Filter: disk driver %d has had "
"%d/%d retry attempts, %d/%d kills\n", which,
driver[which].retries, NR_RETRIES,
driver[which].kills, NR_RESTARTS);
#endif
if (driver[which].retries < NR_RETRIES) {
if(retries == 1) {
#if DEBUG
printf("Filter: not restarting; retrying "
"(retries %d/%d, kills %d/%d)\n",
driver[which].retries, NR_RETRIES,
driver[which].kills, NR_RESTARTS);
#endif
return OK;
}
#if DEBUG
printf("Filter: restarting (retries %d/%d, "
"kills %d/%d, internal retry %d)\n",
driver[which].retries, NR_RETRIES,
driver[which].kills, NR_RESTARTS, retries);
#endif
}
#if DEBUG
printf("Filter: disk driver %d has reached error "
"threshold, restarting driver\n", which);
#endif
*tell_rs = 1;
break;
case BD_DEAD:
/* Can't kill that which is already dead.. */
*tell_rs = 0;
break;
default:
panic("invalid problem: %d", problem);
}
/* At this point, the driver will be restarted. */
driver[which].retries = 0;
driver[which].kills++;
if (driver[which].kills < NR_RESTARTS)
return EAGAIN;
/* We've reached the maximum number of restarts for this driver. */
if (USE_MIRROR) {
printf("Filter: kill threshold reached, disabling mirroring\n");
USE_MIRROR = 0;
if (which == DRIVER_MAIN) {
driver[DRIVER_MAIN] = driver[DRIVER_BACKUP];
/* This is not necessary. */
strcpy(MAIN_LABEL, BACKUP_LABEL);
MAIN_MINOR = BACKUP_MINOR;
}
driver[DRIVER_BACKUP].endpt = NONE;
return OK;
}
else {
/* We tried, we really did. But now we give up. Tell the user.
*/
printf("Filter: kill threshold reached, returning error\n");
if (driver[which].error == EAGAIN) return EIO;
return driver[which].error;
}
}
/*===========================================================================*
* restart_driver *
*===========================================================================*/
static void restart_driver(int which, int tell_rs)
{
/* Restart the given driver. Block until the new instance is up.
*/
message msg;
endpoint_t endpt;
int r, w = 0;
if (tell_rs) {
/* Tell RS to refresh or restart the driver */
msg.m_type = RS_REFRESH;
msg.RS_CMD_ADDR = driver[which].label;
msg.RS_CMD_LEN = strlen(driver[which].label);
#if DEBUG
printf("Filter: asking RS to refresh %s..\n",
driver[which].label);
#endif
r = sendrec(RS_PROC_NR, &msg);
if (r != OK || msg.m_type != OK)
panic("RS request failed: %d", r);
#if DEBUG
printf("Filter: RS call succeeded\n");
#endif
}
/* Wait until the new driver instance is up, and get its endpoint. */
#if DEBUG
printf("Filter: endpoint update driver %d; old endpoint %d\n",
which, driver[which].endpt);
#endif
do {
if(w) flt_sleep(1);
w = 1;
r = ds_retrieve_label_num(driver[which].label,
(u32_t *) &endpt);
#if DEBUG2
if (r != OK)
printf("Filter: DS request failed (%d)\n", r);
else if (endpt == driver[which].endpt)
printf("Filter: DS returned same endpoint\n");
else
printf("Filter: DS request OK, new endpoint\n");
#endif
} while (r != OK || endpt == driver[which].endpt);
driver[which].endpt = endpt;
}
/*===========================================================================*
* check_driver *
*===========================================================================*/
int check_driver(int which)
{
/* See if the given driver has been troublesome, and if so, deal with
* it.
*/
int problem, tell_rs;
int r, retries = 0;
problem = driver[which].problem;
if (problem == BD_NONE)
return OK;
do {
if(retries) {
#if DEBUG
printf("Filter: check_driver: retry number %d\n",
retries);
#endif
problem = BD_PROTO;
}
retries++;
driver[which].problem = BD_NONE;
/* Decide what to do: continue operation, restart the driver,
* or return an error.
*/
r = check_problem(which, problem, retries, &tell_rs);
if (r != EAGAIN)
return r;
/* Restarting the driver it is. First tell RS (if necessary),
* then wait for the new driver instance to come up.
*/
restart_driver(which, tell_rs);
/* Finally, open the device on the new driver */
} while (driver_open(which) != OK);
#if DEBUG
printf("Filter: check_driver restarted driver %d, endpoint %d\n",
which, driver[which].endpt);
#endif
return OK;
}
/*===========================================================================*
* flt_senda *
*===========================================================================*/
static int flt_senda(message *mess, int which)
{
/* Send a message to one driver. Can only return OK at the moment. */
int r;
asynmsg_t *amp;
/* Fill in the last bits of the message. */
mess->DEVICE = driver[which].minor;
mess->IO_ENDPT = self_ep;
/* Send the message asynchronously. */
amp = &amsgtable[which];
amp->dst = driver[which].endpt;
amp->msg = *mess;
amp->flags = AMF_VALID;
r = senda(amsgtable, 2);
if(r != OK)
panic("senda returned error: %d", r);
return r;
}
/*===========================================================================*
* check_senda *
*===========================================================================*/
static int check_senda(int which)
{
/* Check whether an earlier senda resulted in an error indicating the
* message never got delivered. Only in that case can we reliably say
* that the driver died. Return BD_DEAD in this case, and BD_PROTO
* otherwise.
*/
asynmsg_t *amp;
amp = &amsgtable[which];
if ((amp->flags & AMF_DONE) && (amp->result == EDEADSRCDST)) {
return BD_DEAD;
}
return BD_PROTO;
}
/*===========================================================================*
* flt_receive *
*===========================================================================*/
static int flt_receive(message *mess, int which)
{
/* Receive a message from one or either driver, unless a timeout
* occurs. Can only return OK or RET_REDO.
*/
int r;
for (;;) {
r = sef_receive(ANY, mess);
if(r != OK)
panic("sef_receive returned error: %d", r);
if(mess->m_source == CLOCK && is_notify(mess->m_type)) {
if (mess->NOTIFY_TIMESTAMP < flt_alarm(-1)) {
#if DEBUG
printf("Filter: SKIPPING old alarm "
"notification\n");
#endif
continue;
}
#if DEBUG
printf("Filter: timeout waiting for disk driver %d "
"reply!\n", which);
#endif
/* If we're waiting for either driver,
* both are at fault.
*/
if (which < 0) {
bad_driver(DRIVER_MAIN,
check_senda(DRIVER_MAIN), EFAULT);
return bad_driver(DRIVER_BACKUP,
check_senda(DRIVER_BACKUP), EFAULT);
}
/* Otherwise, just report the one not replying as dead.
*/
return bad_driver(which, check_senda(which), EFAULT);
}
if (mess->m_source != driver[DRIVER_MAIN].endpt &&
mess->m_source != driver[DRIVER_BACKUP].endpt) {
#if DEBUG
printf("Filter: got STRAY message %d from %d\n",
mess->m_type, mess->m_source);
#endif
continue;
}
/* We are waiting for a reply from one specific driver. */
if (which >= 0) {
/* If the message source is that driver, good. */
if (mess->m_source == driver[which].endpt)
break;
/* This should probably be treated as a real protocol
* error. We do not abort any receives (not even paired
* receives) except because of timeouts. Getting here
* means a driver replied at least the timeout period
* later than expected, which should be enough reason
* to kill it really. The other explanation is that it
* is actually violating the protocol and sending bogus
* messages...
*/
#if DEBUG
printf("Filter: got UNEXPECTED reply from %d\n",
mess->m_source);
#endif
continue;
}
/* We got a message from one of the drivers, and we didn't
* care which one we wanted to receive from. A-OK.
*/
break;
}
return OK;
}
/*===========================================================================*
* flt_sendrec *
*===========================================================================*/
static int flt_sendrec(message *mess, int which)
{
int r;
r = flt_senda(mess, which);
if(r != OK)
return r;
if(check_senda(which) == BD_DEAD) {
return bad_driver(which, BD_DEAD, EFAULT);
}
/* Set alarm. */
flt_alarm(DRIVER_TIMEOUT);
r = flt_receive(mess, which);
/* Clear the alarm. */
flt_alarm(0);
return r;
}
/*===========================================================================*
* do_sendrec_both *
*===========================================================================*/
static int do_sendrec_both(message *m1, message *m2)
{
/* If USEE_MIRROR is set, call flt_sendrec() to both drivers.
* Otherwise, only call flt_sendrec() to the main driver.
* This function will only return either OK or RET_REDO.
*/
int r, which = -1;
message ma, mb;
/* If the two disks use the same driver, call flt_sendrec() twice
* sequentially. Such a setup is not very useful though.
*/
if (!strcmp(driver[DRIVER_MAIN].label, driver[DRIVER_BACKUP].label)) {
if ((r = flt_sendrec(m1, DRIVER_MAIN)) != OK) return r;
return flt_sendrec(m2, DRIVER_BACKUP);
}
/* If the two disks use different drivers, call flt_senda()
* twice, and then flt_receive(), and distinguish the return
* messages by means of m_source.
*/
if ((r = flt_senda(m1, DRIVER_MAIN)) != OK) return r;
if ((r = flt_senda(m2, DRIVER_BACKUP)) != OK) return r;
/* Set alarm. */
flt_alarm(DRIVER_TIMEOUT);
/* The message received by the 1st flt_receive() may not be
* from DRIVER_MAIN.
*/
if ((r = flt_receive(&ma, -1)) != OK) {
flt_alarm(0);
return r;
}
if (ma.m_source == driver[DRIVER_MAIN].endpt) {
which = DRIVER_BACKUP;
} else if (ma.m_source == driver[DRIVER_BACKUP].endpt) {
which = DRIVER_MAIN;
} else {
panic("message from unexpected source: %d",
ma.m_source);
}
r = flt_receive(&mb, which);
/* Clear the alarm. */
flt_alarm(0);
if(r != OK)
return r;
if (ma.m_source == driver[DRIVER_MAIN].endpt) {
*m1 = ma;
*m2 = mb;
} else {
*m1 = mb;
*m2 = ma;
}
return OK;
}
/*===========================================================================*
* do_sendrec_one *
*===========================================================================*/
static int do_sendrec_one(message *m1, message *m2)
{
/* Only talk to the main driver. If something goes wrong, it will
* be fixed elsewhere.
* This function will only return either OK or RET_REDO.
*/
return flt_sendrec(m1, DRIVER_MAIN);
}
/*===========================================================================*
* paired_sendrec *
*===========================================================================*/
static int paired_sendrec(message *m1, message *m2, int both)
{
/* Sendrec with the disk driver. If the disk driver is down, and was
* restarted, redo the request, until the driver works fine, or can't
* be restarted again.
*/
int r;
#if DEBUG2
printf("paired_sendrec(%d) - <%d,%x:%x,%d> - %x,%x\n",
both, m1->m_type, m1->HIGHPOS, m1->POSITION, m1->COUNT,
m1->IO_GRANT, m2->IO_GRANT);
#endif
if (both)
r = do_sendrec_both(m1, m2);
else
r = do_sendrec_one(m1, m2);
#if DEBUG2
if (r != OK)
printf("paired_sendrec about to return %d\n", r);
#endif
return r;
}
/*===========================================================================*
* single_grant *
*===========================================================================*/
static int single_grant(endpoint_t endpt, vir_bytes buf, int access,
cp_grant_id_t *gid, iovec_s_t vector[NR_IOREQS], size_t *sizep)
{
/* Create grants for a vectored request to a single driver.
*/
cp_grant_id_t grant;
size_t size, chunk;
int count;
size = *sizep;
/* Split up the request into chunks, if requested. This makes no
* difference at all, except that this works around a weird performance
* bug with large DMA PRDs on some machines.
*/
if (CHUNK_SIZE > 0) chunk = CHUNK_SIZE;
else chunk = size;
/* Fill in the vector, creating a grant for each item. */
for (count = 0; size > 0 && count < NR_IOREQS; count++) {
/* The last chunk will contain all the remaining data. */
if (chunk > size || count == NR_IOREQS - 1)
chunk = size;
grant = cpf_grant_direct(endpt, buf, chunk, access);
if (!GRANT_VALID(grant))
panic("invalid grant: %d", grant);
vector[count].iov_grant = grant;
vector[count].iov_size = chunk;
buf += chunk;
size -= chunk;
}
/* Then create a grant for the vector itself. */
*gid = cpf_grant_direct(endpt, (vir_bytes) vector,
sizeof(vector[0]) * count, CPF_READ | CPF_WRITE);
if (!GRANT_VALID(*gid))
panic("invalid grant: %d", *gid);
return count;
}
/*===========================================================================*
* paired_grant *
*===========================================================================*/
static int paired_grant(char *buf1, char *buf2, int request,
cp_grant_id_t *gids, iovec_s_t vectors[2][NR_IOREQS], size_t *sizes,
int both)
{
/* Create memory grants, either to one or to both drivers.
*/
int count, access;
count = 0;
access = (request == FLT_WRITE) ? CPF_READ : CPF_WRITE;
if(driver[DRIVER_MAIN].endpt > 0) {
count = single_grant(driver[DRIVER_MAIN].endpt,
(vir_bytes) buf1, access, &gids[0], vectors[0],
&sizes[0]);
}
if (both) {
if(driver[DRIVER_BACKUP].endpt > 0) {
count = single_grant(driver[DRIVER_BACKUP].endpt,
(vir_bytes) buf2, access, &gids[1],
vectors[1], &sizes[1]);
}
}
return count;
}
/*===========================================================================*
* single_revoke *
*===========================================================================*/
PRIVATE void single_revoke(cp_grant_id_t gid, iovec_s_t vector[NR_IOREQS],
size_t *sizep, int count)
{
/* Revoke all grants associated with a request to a single driver.
* Modify the given size to reflect the actual I/O performed.
*/
int i;
/* Revoke the grants for all the elements of the vector. */
for (i = 0; i < count; i++) {
cpf_revoke(vector[i].iov_grant);
*sizep -= vector[i].iov_size;
}
/* Then revoke the grant for the vector itself. */
cpf_revoke(gid);
}
/*===========================================================================*
* paired_revoke *
*===========================================================================*/
static void paired_revoke(cp_grant_id_t *gids, iovec_s_t vectors[2][NR_IOREQS],
size_t *sizes, int count, int both)
{
/* Revoke grants to drivers for a single request.
*/
single_revoke(gids[0], vectors[0], &sizes[0], count);
if (both)
single_revoke(gids[1], vectors[1], &sizes[1], count);
}
/*===========================================================================*
* read_write *
*===========================================================================*/
int read_write(u64_t pos, char *bufa, char *bufb, size_t *sizep, int request)
{
iovec_s_t vectors[2][NR_IOREQS];
message m1, m2;
cp_grant_id_t gids[2];
size_t sizes[2];
int r, both, count;
gids[0] = gids[1] = GRANT_INVALID;
sizes[0] = sizes[1] = *sizep;
/* Send two requests only if mirroring is enabled and the given request
* is either FLT_READ2 or FLT_WRITE.
*/
both = (USE_MIRROR && request != FLT_READ);
count = paired_grant(bufa, bufb, request, gids, vectors, sizes, both);
m1.m_type = (request == FLT_WRITE) ? DEV_SCATTER_S : DEV_GATHER_S;
m1.COUNT = count;
m1.POSITION = ex64lo(pos);
m1.HIGHPOS = ex64hi(pos);
m2 = m1;
m1.IO_GRANT = (char *) gids[0];
m2.IO_GRANT = (char *) gids[1];
r = paired_sendrec(&m1, &m2, both);
paired_revoke(gids, vectors, sizes, count, both);
if(r != OK) {
#if DEBUG
if (r != RET_REDO)
printf("Filter: paired_sendrec returned %d\n", r);
#endif
return r;
}
if (m1.m_type != TASK_REPLY || m1.REP_STATUS != OK) {
printf("Filter: unexpected/invalid reply from main driver: "
"(%x, %d)\n", m1.m_type, m1.REP_STATUS);
return bad_driver(DRIVER_MAIN, BD_PROTO,
(m1.m_type == TASK_REPLY) ? m1.REP_STATUS : EFAULT);
}
if (sizes[0] != *sizep) {
printf("Filter: truncated reply from main driver\n");
/* If the driver returned a value *larger* than we requested,
* OR if we did NOT exceed the disk size, then we should
* report the driver for acting strangely!
*/
if (sizes[0] < 0 || sizes[0] > *sizep ||
cmp64(add64u(pos, sizes[0]), disk_size) < 0)
return bad_driver(DRIVER_MAIN, BD_PROTO, EFAULT);
/* Return the actual size. */
*sizep = sizes[0];
}
if (both) {
if (m2.m_type != TASK_REPLY || m2.REP_STATUS != OK) {
printf("Filter: unexpected/invalid reply from "
"backup driver (%x, %d)\n",
m2.m_type, m2.REP_STATUS);
return bad_driver(DRIVER_BACKUP, BD_PROTO,
m2.m_type == TASK_REPLY ? m2.REP_STATUS :
EFAULT);
}
if (sizes[1] != *sizep) {
printf("Filter: truncated reply from backup driver\n");
/* As above */
if (sizes[1] < 0 || sizes[1] > *sizep ||
cmp64(add64u(pos, sizes[1]), disk_size) < 0)
return bad_driver(DRIVER_BACKUP, BD_PROTO,
EFAULT);
/* Return the actual size. */
if (*sizep >= sizes[1])
*sizep = sizes[1];
}
}
return OK;
}
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