minix/drivers/filter/main.c

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2009-12-02 11:08:58 +01:00
/* Filter driver - top layer - block interface */
/* This is a filter driver, which lays above disk driver, and forwards
* messages between disk driver and its callers. The filter can detect
* corrupted data (toggled by USE_CHECKSUM) and recover it (toggled
* by USE_MIRROR). These two functions are independent from each other.
* The mirroring function requires two disks, on separate disk drivers.
*/
#include "inc.h"
#include "optset.h"
#define _POSIX_SOURCE 1
#include <signal.h>
/* Global settings. */
int USE_CHECKSUM = 0; /* enable checksumming */
int USE_MIRROR = 0; /* enable mirroring */
int BAD_SUM_ERROR = 1; /* bad checksums are considered a driver error */
int USE_SUM_LAYOUT = 0; /* use checksumming layout on disk */
int NR_SUM_SEC = 8; /* number of checksums per checksum sector */
int SUM_TYPE = ST_CRC; /* use NIL, XOR, CRC, or MD5 */
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int SUM_SIZE = 0; /* size of the stored checksum */
int NR_RETRIES = 3; /* number of times the request will be retried (N) */
int NR_RESTARTS = 3; /* number of times a driver will be restarted (M) */
int DRIVER_TIMEOUT = 5; /* timeout in seconds to declare a driver dead (T) */
int CHUNK_SIZE = 0; /* driver requests will be vectorized at this size */
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char MAIN_LABEL[LABEL_SIZE] = ""; /* main disk driver label */
char BACKUP_LABEL[LABEL_SIZE] = ""; /* backup disk driver label */
int MAIN_MINOR = -1; /* main partition minor nr */
int BACKUP_MINOR = -1; /* backup partition minor nr */
PRIVATE struct optset optset_table[] = {
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{ "label0", OPT_STRING, MAIN_LABEL, LABEL_SIZE },
{ "label1", OPT_STRING, BACKUP_LABEL, LABEL_SIZE },
{ "minor0", OPT_INT, &MAIN_MINOR, 10 },
{ "minor1", OPT_INT, &BACKUP_MINOR, 10 },
{ "sum_sec", OPT_INT, &NR_SUM_SEC, 10 },
{ "layout", OPT_BOOL, &USE_SUM_LAYOUT, 1 },
{ "nolayout", OPT_BOOL, &USE_SUM_LAYOUT, 0 },
{ "sum", OPT_BOOL, &USE_CHECKSUM, 1 },
{ "nosum", OPT_BOOL, &USE_CHECKSUM, 0 },
{ "mirror", OPT_BOOL, &USE_MIRROR, 1 },
{ "nomirror", OPT_BOOL, &USE_MIRROR, 0 },
{ "nil", OPT_BOOL, &SUM_TYPE, ST_NIL },
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{ "xor", OPT_BOOL, &SUM_TYPE, ST_XOR },
{ "crc", OPT_BOOL, &SUM_TYPE, ST_CRC },
{ "md5", OPT_BOOL, &SUM_TYPE, ST_MD5 },
{ "sumerr", OPT_BOOL, &BAD_SUM_ERROR, 1 },
{ "nosumerr", OPT_BOOL, &BAD_SUM_ERROR, 0 },
{ "retries", OPT_INT, &NR_RETRIES, 10 },
{ "N", OPT_INT, &NR_RETRIES, 10 },
{ "restarts", OPT_INT, &NR_RESTARTS, 10 },
{ "M", OPT_INT, &NR_RESTARTS, 10 },
{ "timeout", OPT_INT, &DRIVER_TIMEOUT, 10 },
{ "T", OPT_INT, &DRIVER_TIMEOUT, 10 },
{ "chunk", OPT_INT, &CHUNK_SIZE, 10 },
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{ NULL }
};
/* Request message. */
static message m_in;
static endpoint_t who_e; /* m_source */
static endpoint_t proc_e; /* IO_ENDPT */
static cp_grant_id_t grant_id; /* IO_GRANT */
/* Data buffers. */
static char *buf_array, *buffer; /* contiguous buffer */
Initialization protocol for system services. SYSLIB CHANGES: - SEF framework now supports a new SEF Init request type from RS. 3 different callbacks are available (init_fresh, init_lu, init_restart) to specify initialization code when a service starts fresh, starts after a live update, or restarts. SYSTEM SERVICE CHANGES: - Initialization code for system services is now enclosed in a callback SEF will automatically call at init time. The return code of the callback will tell RS whether the initialization completed successfully. - Each init callback can access information passed by RS to initialize. As of now, each system service has access to the public entries of RS's system process table to gather all the information required to initialize. This design eliminates many existing or potential races at boot time and provides a uniform initialization interface to system services. The same interface will be reused for the upcoming publish/subscribe model to handle dynamic registration / deregistration of system services. VM CHANGES: - Uniform privilege management for all system services. Every service uses the same call mask format. For boot services, VM copies the call mask from init data. For dynamic services, VM still receives the call mask via rs_set_priv call that will be soon replaced by the upcoming publish/subscribe model. RS CHANGES: - The system process table has been reorganized and split into private entries and public entries. Only the latter ones are exposed to system services. - VM call masks are now entirely configured in rs/table.c - RS has now its own slot in the system process table. Only kernel tasks and user processes not included in the boot image are now left out from the system process table. - RS implements the initialization protocol for system services. - For services in the boot image, RS blocks till initialization is complete and panics when failure is reported back. Services are initialized in their order of appearance in the boot image priv table and RS blocks to implements synchronous initialization for every system service having the flag SF_SYNCH_BOOT set. - For services started dynamically, the initialization protocol is implemented as though it were the first ping for the service. In this case, if the system service fails to report back (or reports failure), RS brings the service down rather than trying to restart it.
2010-01-08 02:20:42 +01:00
/* SEF functions and variables. */
FORWARD _PROTOTYPE( void sef_local_startup, (void) );
FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
New RS and new signal handling for system processes. UPDATING INFO: 20100317: /usr/src/etc/system.conf updated to ignore default kernel calls: copy it (or merge it) to /etc/system.conf. The hello driver (/dev/hello) added to the distribution: # cd /usr/src/commands/scripts && make clean install # cd /dev && MAKEDEV hello KERNEL CHANGES: - Generic signal handling support. The kernel no longer assumes PM as a signal manager for every process. The signal manager of a given process can now be specified in its privilege slot. When a signal has to be delivered, the kernel performs the lookup and forwards the signal to the appropriate signal manager. PM is the default signal manager for user processes, RS is the default signal manager for system processes. To enable ptrace()ing for system processes, it is sufficient to change the default signal manager to PM. This will temporarily disable crash recovery, though. - sys_exit() is now split into sys_exit() (i.e. exit() for system processes, which generates a self-termination signal), and sys_clear() (i.e. used by PM to ask the kernel to clear a process slot when a process exits). - Added a new kernel call (i.e. sys_update()) to swap two process slots and implement live update. PM CHANGES: - Posix signal handling is no longer allowed for system processes. System signals are split into two fixed categories: termination and non-termination signals. When a non-termination signaled is processed, PM transforms the signal into an IPC message and delivers the message to the system process. When a termination signal is processed, PM terminates the process. - PM no longer assumes itself as the signal manager for system processes. It now makes sure that every system signal goes through the kernel before being actually processes. The kernel will then dispatch the signal to the appropriate signal manager which may or may not be PM. SYSLIB CHANGES: - Simplified SEF init and LU callbacks. - Added additional predefined SEF callbacks to debug crash recovery and live update. - Fixed a temporary ack in the SEF init protocol. SEF init reply is now completely synchronous. - Added SEF signal event type to provide a uniform interface for system processes to deal with signals. A sef_cb_signal_handler() callback is available for system processes to handle every received signal. A sef_cb_signal_manager() callback is used by signal managers to process system signals on behalf of the kernel. - Fixed a few bugs with memory mapping and DS. VM CHANGES: - Page faults and memory requests coming from the kernel are now implemented using signals. - Added a new VM call to swap two process slots and implement live update. - The call is used by RS at update time and in turn invokes the kernel call sys_update(). RS CHANGES: - RS has been reworked with a better functional decomposition. - Better kernel call masks. com.h now defines the set of very basic kernel calls every system service is allowed to use. This makes system.conf simpler and easier to maintain. In addition, this guarantees a higher level of isolation for system libraries that use one or more kernel calls internally (e.g. printf). - RS is the default signal manager for system processes. By default, RS intercepts every signal delivered to every system process. This makes crash recovery possible before bringing PM and friends in the loop. - RS now supports fast rollback when something goes wrong while initializing the new version during a live update. - Live update is now implemented by keeping the two versions side-by-side and swapping the process slots when the old version is ready to update. - Crash recovery is now implemented by keeping the two versions side-by-side and cleaning up the old version only when the recovery process is complete. DS CHANGES: - Fixed a bug when the process doing ds_publish() or ds_delete() is not known by DS. - Fixed the completely broken support for strings. String publishing is now implemented in the system library and simply wraps publishing of memory ranges. Ideally, we should adopt a similar approach for other data types as well. - Test suite fixed. DRIVER CHANGES: - The hello driver has been added to the Minix distribution to demonstrate basic live update and crash recovery functionalities. - Other drivers have been adapted to conform the new SEF interface.
2010-03-17 02:15:29 +01:00
FORWARD _PROTOTYPE( void sef_cb_signal_handler, (int signo) );
Initialization protocol for system services. SYSLIB CHANGES: - SEF framework now supports a new SEF Init request type from RS. 3 different callbacks are available (init_fresh, init_lu, init_restart) to specify initialization code when a service starts fresh, starts after a live update, or restarts. SYSTEM SERVICE CHANGES: - Initialization code for system services is now enclosed in a callback SEF will automatically call at init time. The return code of the callback will tell RS whether the initialization completed successfully. - Each init callback can access information passed by RS to initialize. As of now, each system service has access to the public entries of RS's system process table to gather all the information required to initialize. This design eliminates many existing or potential races at boot time and provides a uniform initialization interface to system services. The same interface will be reused for the upcoming publish/subscribe model to handle dynamic registration / deregistration of system services. VM CHANGES: - Uniform privilege management for all system services. Every service uses the same call mask format. For boot services, VM copies the call mask from init data. For dynamic services, VM still receives the call mask via rs_set_priv call that will be soon replaced by the upcoming publish/subscribe model. RS CHANGES: - The system process table has been reorganized and split into private entries and public entries. Only the latter ones are exposed to system services. - VM call masks are now entirely configured in rs/table.c - RS has now its own slot in the system process table. Only kernel tasks and user processes not included in the boot image are now left out from the system process table. - RS implements the initialization protocol for system services. - For services in the boot image, RS blocks till initialization is complete and panics when failure is reported back. Services are initialized in their order of appearance in the boot image priv table and RS blocks to implements synchronous initialization for every system service having the flag SF_SYNCH_BOOT set. - For services started dynamically, the initialization protocol is implemented as though it were the first ping for the service. In this case, if the system service fails to report back (or reports failure), RS brings the service down rather than trying to restart it.
2010-01-08 02:20:42 +01:00
EXTERN int env_argc;
EXTERN char **env_argv;
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/*===========================================================================*
* carry *
*===========================================================================*/
static int carry(size_t size, int flag_rw)
{
/* Carry data between caller proc and filter.
*/
if (flag_rw == FLT_WRITE)
return sys_safecopyfrom(proc_e, grant_id, 0,
(vir_bytes) buffer, size, D);
else
return sys_safecopyto(proc_e, grant_id, 0,
(vir_bytes) buffer, size, D);
}
/*===========================================================================*
* vcarry *
*===========================================================================*/
static int vcarry(int grants, iovec_t *iov, int flag_rw, size_t size)
{
/* Carry data between caller proc and filter, through grant-vector.
*/
char *bufp;
int i, r;
size_t bytes;
bufp = buffer;
for(i = 0; i < grants && size > 0; i++) {
bytes = MIN(size, iov[i].iov_size);
if (flag_rw == FLT_WRITE)
r = sys_safecopyfrom(proc_e,
(vir_bytes) iov[i].iov_addr, 0,
(vir_bytes) bufp, bytes, D);
else
r = sys_safecopyto(proc_e,
(vir_bytes) iov[i].iov_addr, 0,
(vir_bytes) bufp, bytes, D);
if(r != OK)
return r;
bufp += bytes;
size -= bytes;
}
return OK;
}
/*===========================================================================*
* do_rdwt *
*===========================================================================*/
static int do_rdwt(int flag_rw)
{
size_t size, size_ret;
u64_t pos;
int r;
pos = make64(m_in.POSITION, m_in.HIGHPOS);
size = m_in.COUNT;
if (rem64u(pos, SECTOR_SIZE) != 0 || size % SECTOR_SIZE != 0) {
printf("Filter: unaligned request from caller!\n");
return EINVAL;
}
buffer = flt_malloc(size, buf_array, BUF_SIZE);
if(flag_rw == FLT_WRITE)
carry(size, flag_rw);
reset_kills();
for (;;) {
size_ret = size;
r = transfer(pos, buffer, &size_ret, flag_rw);
if(r != RET_REDO)
break;
#if DEBUG
printf("Filter: transfer yielded RET_REDO, checking drivers\n");
#endif
if((r = check_driver(DRIVER_MAIN)) != OK) break;
if((r = check_driver(DRIVER_BACKUP)) != OK) break;
}
if(r == OK && flag_rw == FLT_READ)
carry(size_ret, flag_rw);
flt_free(buffer, size, buf_array);
return r != OK ? r : size_ret;
}
/*===========================================================================*
* do_vrdwt *
*===========================================================================*/
static int do_vrdwt(int flag_rw)
{
size_t size, size_ret, bytes;
int grants;
int r, i;
u64_t pos;
iovec_t iov_proc[NR_IOREQS];
/* Extract informations. */
grants = m_in.COUNT;
if((r = sys_safecopyfrom(who_e, grant_id, 0, (vir_bytes) iov_proc,
grants * sizeof(iovec_t), D)) != OK) {
panic("copying in grant vector failed: %d", r);
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}
pos = make64(m_in.POSITION, m_in.HIGHPOS);
for(size = 0, i = 0; i < grants; i++)
size += iov_proc[i].iov_size;
if (rem64u(pos, SECTOR_SIZE) != 0 || size % SECTOR_SIZE != 0) {
printf("Filter: unaligned request from caller!\n");
return EINVAL;
}
buffer = flt_malloc(size, buf_array, BUF_SIZE);
if(flag_rw == FLT_WRITE)
vcarry(grants, iov_proc, flag_rw, size);
reset_kills();
for (;;) {
size_ret = size;
r = transfer(pos, buffer, &size_ret, flag_rw);
if(r != RET_REDO)
break;
#if DEBUG
printf("Filter: transfer yielded RET_REDO, checking drivers\n");
#endif
if((r = check_driver(DRIVER_MAIN)) != OK) break;
if((r = check_driver(DRIVER_BACKUP)) != OK) break;
}
if(r != OK) {
flt_free(buffer, size, buf_array);
return r;
}
if(flag_rw == FLT_READ)
vcarry(grants, iov_proc, flag_rw, size_ret);
/* Set the result-iovec. */
for(i = 0; i < grants && size_ret > 0; i++) {
bytes = MIN(size_ret, iov_proc[i].iov_size);
iov_proc[i].iov_size -= bytes;
size_ret -= bytes;
}
/* Copy the caller's grant-table back. */
if((r = sys_safecopyto(who_e, grant_id, 0, (vir_bytes) iov_proc,
grants * sizeof(iovec_t), D)) != OK) {
panic("copying out grant vector failed: %d", r);
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}
flt_free(buffer, size, buf_array);
return OK;
}
/*===========================================================================*
* do_ioctl *
*===========================================================================*/
static int do_ioctl(message *m)
{
struct partition sizepart;
switch(m->REQUEST) {
case DIOCSETP:
case DIOCTIMEOUT:
case DIOCOPENCT:
/* These do not make sense for us. */
return EINVAL;
case DIOCGETP:
memset(&sizepart, 0, sizeof(sizepart));
/* The presented disk size is the raw partition size,
* corrected for space needed for checksums.
*/
sizepart.size = convert(get_raw_size());
if(sys_safecopyto(proc_e, (vir_bytes) grant_id, 0,
(vir_bytes) &sizepart,
sizeof(struct partition), D) != OK) {
printf("Filter: DIOCGETP safecopyto failed\n");
return EIO;
}
break;
default:
printf("Filter: unknown ioctl request: %d!\n", m->REQUEST);
return EINVAL;
}
return OK;
}
/*===========================================================================*
* parse_arguments *
*===========================================================================*/
static int parse_arguments(int argc, char *argv[])
{
if(argc != 2)
return EINVAL;
optset_parse(optset_table, argv[1]);
if (MAIN_LABEL[0] == 0 || MAIN_MINOR < 0 || MAIN_MINOR > 255)
return EINVAL;
if (USE_MIRROR && (BACKUP_LABEL[0] == 0 ||
BACKUP_MINOR < 0 || BACKUP_MINOR > 255))
return EINVAL;
/* Checksumming implies a checksum layout. */
if (USE_CHECKSUM)
USE_SUM_LAYOUT = 1;
/* Determine the checksum size for the chosen checksum type. */
switch (SUM_TYPE) {
case ST_NIL:
SUM_SIZE = 4; /* for the sector number */
break;
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case ST_XOR:
SUM_SIZE = 16; /* compatibility */
break;
case ST_CRC:
SUM_SIZE = 4;
break;
case ST_MD5:
SUM_SIZE = 16;
break;
default:
return EINVAL;
}
if (NR_SUM_SEC <= 0 || SUM_SIZE * NR_SUM_SEC > SECTOR_SIZE)
return EINVAL;
#if DEBUG
printf("Filter starting. Configuration:\n");
printf(" USE_CHECKSUM : %3s ", USE_CHECKSUM ? "yes" : "no");
printf(" USE_MIRROR : %3s\n", USE_MIRROR ? "yes" : "no");
if (USE_CHECKSUM) {
printf(" BAD_SUM_ERROR : %3s ",
BAD_SUM_ERROR ? "yes" : "no");
printf(" NR_SUM_SEC : %3d\n", NR_SUM_SEC);
printf(" SUM_TYPE : ");
switch (SUM_TYPE) {
case ST_NIL: printf("nil"); break;
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case ST_XOR: printf("xor"); break;
case ST_CRC: printf("crc"); break;
case ST_MD5: printf("md5"); break;
}
printf(" SUM_SIZE : %3d\n", SUM_SIZE);
}
else printf(" USE_SUM_LAYOUT : %3s\n", USE_SUM_LAYOUT ? "yes" : "no");
printf(" N : %3dx M : %3dx T : %3ds\n",
NR_RETRIES, NR_RESTARTS, DRIVER_TIMEOUT);
printf(" MAIN_LABEL / MAIN_MINOR : %19s / %d\n",
MAIN_LABEL, MAIN_MINOR);
if (USE_MIRROR) {
printf(" BACKUP_LABEL / BACKUP_MINOR : %15s / %d\n",
BACKUP_LABEL, BACKUP_MINOR);
}
#endif
/* Convert timeout seconds to ticks. */
DRIVER_TIMEOUT *= sys_hz();
return OK;
}
/*===========================================================================*
* main *
*===========================================================================*/
int main(int argc, char *argv[])
{
message m_out;
int r;
Basic System Event Framework (SEF) with ping and live update. SYSLIB CHANGES: - SEF must be used by every system process and is thereby part of the system library. - The framework provides a receive() interface (sef_receive) for system processes to automatically catch known system even messages and process them. - SEF provides a default behavior for each type of system event, but allows system processes to register callbacks to override the default behavior. - Custom (local to the process) or predefined (provided by SEF) callback implementations can be registered to SEF. - SEF currently includes support for 2 types of system events: 1. SEF Ping. The event occurs every time RS sends a ping to figure out whether a system process is still alive. The default callback implementation provided by SEF is to notify RS back to let it know the process is alive and kicking. 2. SEF Live update. The event occurs every time RS sends a prepare to update message to let a system process know an update is available and to prepare for it. The live update support is very basic for now. SEF only deals with verifying if the prepare state can be supported by the process, dumping the state for debugging purposes, and providing an event-driven programming model to the process to react to state changes check-in when ready to update. - SEF should be extended in the future to integrate support for more types of system events. Ideally, all the cross-cutting concerns should be integrated into SEF to avoid duplicating code and ease extensibility. Examples include: * PM notify messages primarily used at shutdown. * SYSTEM notify messages primarily used for signals. * CLOCK notify messages used for system alarms. * Debug messages. IS could still be in charge of fkey handling but would forward the debug message to the target process (e.g. PM, if the user requested debug information about PM). SEF would then catch the message and do nothing unless the process has registered an appropriate callback to deal with the event. This simplifies the programming model to print debug information, avoids duplicating code, and reduces the effort to print debug information. SYSTEM PROCESSES CHANGES: - Every system process registers SEF callbacks it needs to override the default system behavior and calls sef_startup() right after being started. - sef_startup() does almost nothing now, but will be extended in the future to support callbacks of its own to let RS control and synchronize with every system process at initialization time. - Every system process calls sef_receive() now rather than receive() directly, to let SEF handle predefined system events. RS CHANGES: - RS supports a basic single-component live update protocol now, as follows: * When an update command is issued (via "service update *"), RS notifies the target system process to prepare for a specific update state. * If the process doesn't respond back in time, the update is aborted. * When the process responds back, RS kills it and marks it for refreshing. * The process is then automatically restarted as for a buggy process and can start running again. * Live update is currently prototyped as a controlled failure.
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/* SEF local startup. */
Initialization protocol for system services. SYSLIB CHANGES: - SEF framework now supports a new SEF Init request type from RS. 3 different callbacks are available (init_fresh, init_lu, init_restart) to specify initialization code when a service starts fresh, starts after a live update, or restarts. SYSTEM SERVICE CHANGES: - Initialization code for system services is now enclosed in a callback SEF will automatically call at init time. The return code of the callback will tell RS whether the initialization completed successfully. - Each init callback can access information passed by RS to initialize. As of now, each system service has access to the public entries of RS's system process table to gather all the information required to initialize. This design eliminates many existing or potential races at boot time and provides a uniform initialization interface to system services. The same interface will be reused for the upcoming publish/subscribe model to handle dynamic registration / deregistration of system services. VM CHANGES: - Uniform privilege management for all system services. Every service uses the same call mask format. For boot services, VM copies the call mask from init data. For dynamic services, VM still receives the call mask via rs_set_priv call that will be soon replaced by the upcoming publish/subscribe model. RS CHANGES: - The system process table has been reorganized and split into private entries and public entries. Only the latter ones are exposed to system services. - VM call masks are now entirely configured in rs/table.c - RS has now its own slot in the system process table. Only kernel tasks and user processes not included in the boot image are now left out from the system process table. - RS implements the initialization protocol for system services. - For services in the boot image, RS blocks till initialization is complete and panics when failure is reported back. Services are initialized in their order of appearance in the boot image priv table and RS blocks to implements synchronous initialization for every system service having the flag SF_SYNCH_BOOT set. - For services started dynamically, the initialization protocol is implemented as though it were the first ping for the service. In this case, if the system service fails to report back (or reports failure), RS brings the service down rather than trying to restart it.
2010-01-08 02:20:42 +01:00
env_setargs(argc, argv);
Basic System Event Framework (SEF) with ping and live update. SYSLIB CHANGES: - SEF must be used by every system process and is thereby part of the system library. - The framework provides a receive() interface (sef_receive) for system processes to automatically catch known system even messages and process them. - SEF provides a default behavior for each type of system event, but allows system processes to register callbacks to override the default behavior. - Custom (local to the process) or predefined (provided by SEF) callback implementations can be registered to SEF. - SEF currently includes support for 2 types of system events: 1. SEF Ping. The event occurs every time RS sends a ping to figure out whether a system process is still alive. The default callback implementation provided by SEF is to notify RS back to let it know the process is alive and kicking. 2. SEF Live update. The event occurs every time RS sends a prepare to update message to let a system process know an update is available and to prepare for it. The live update support is very basic for now. SEF only deals with verifying if the prepare state can be supported by the process, dumping the state for debugging purposes, and providing an event-driven programming model to the process to react to state changes check-in when ready to update. - SEF should be extended in the future to integrate support for more types of system events. Ideally, all the cross-cutting concerns should be integrated into SEF to avoid duplicating code and ease extensibility. Examples include: * PM notify messages primarily used at shutdown. * SYSTEM notify messages primarily used for signals. * CLOCK notify messages used for system alarms. * Debug messages. IS could still be in charge of fkey handling but would forward the debug message to the target process (e.g. PM, if the user requested debug information about PM). SEF would then catch the message and do nothing unless the process has registered an appropriate callback to deal with the event. This simplifies the programming model to print debug information, avoids duplicating code, and reduces the effort to print debug information. SYSTEM PROCESSES CHANGES: - Every system process registers SEF callbacks it needs to override the default system behavior and calls sef_startup() right after being started. - sef_startup() does almost nothing now, but will be extended in the future to support callbacks of its own to let RS control and synchronize with every system process at initialization time. - Every system process calls sef_receive() now rather than receive() directly, to let SEF handle predefined system events. RS CHANGES: - RS supports a basic single-component live update protocol now, as follows: * When an update command is issued (via "service update *"), RS notifies the target system process to prepare for a specific update state. * If the process doesn't respond back in time, the update is aborted. * When the process responds back, RS kills it and marks it for refreshing. * The process is then automatically restarted as for a buggy process and can start running again. * Live update is currently prototyped as a controlled failure.
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sef_local_startup();
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for (;;) {
/* Wait for request. */
Basic System Event Framework (SEF) with ping and live update. SYSLIB CHANGES: - SEF must be used by every system process and is thereby part of the system library. - The framework provides a receive() interface (sef_receive) for system processes to automatically catch known system even messages and process them. - SEF provides a default behavior for each type of system event, but allows system processes to register callbacks to override the default behavior. - Custom (local to the process) or predefined (provided by SEF) callback implementations can be registered to SEF. - SEF currently includes support for 2 types of system events: 1. SEF Ping. The event occurs every time RS sends a ping to figure out whether a system process is still alive. The default callback implementation provided by SEF is to notify RS back to let it know the process is alive and kicking. 2. SEF Live update. The event occurs every time RS sends a prepare to update message to let a system process know an update is available and to prepare for it. The live update support is very basic for now. SEF only deals with verifying if the prepare state can be supported by the process, dumping the state for debugging purposes, and providing an event-driven programming model to the process to react to state changes check-in when ready to update. - SEF should be extended in the future to integrate support for more types of system events. Ideally, all the cross-cutting concerns should be integrated into SEF to avoid duplicating code and ease extensibility. Examples include: * PM notify messages primarily used at shutdown. * SYSTEM notify messages primarily used for signals. * CLOCK notify messages used for system alarms. * Debug messages. IS could still be in charge of fkey handling but would forward the debug message to the target process (e.g. PM, if the user requested debug information about PM). SEF would then catch the message and do nothing unless the process has registered an appropriate callback to deal with the event. This simplifies the programming model to print debug information, avoids duplicating code, and reduces the effort to print debug information. SYSTEM PROCESSES CHANGES: - Every system process registers SEF callbacks it needs to override the default system behavior and calls sef_startup() right after being started. - sef_startup() does almost nothing now, but will be extended in the future to support callbacks of its own to let RS control and synchronize with every system process at initialization time. - Every system process calls sef_receive() now rather than receive() directly, to let SEF handle predefined system events. RS CHANGES: - RS supports a basic single-component live update protocol now, as follows: * When an update command is issued (via "service update *"), RS notifies the target system process to prepare for a specific update state. * If the process doesn't respond back in time, the update is aborted. * When the process responds back, RS kills it and marks it for refreshing. * The process is then automatically restarted as for a buggy process and can start running again. * Live update is currently prototyped as a controlled failure.
2009-12-21 15:12:21 +01:00
if(sef_receive(ANY, &m_in) != OK) {
panic("sef_receive failed");
2009-12-02 11:08:58 +01:00
}
#if DEBUG2
printf("Filter: got request %d from %d\n",
m_in.m_type, m_in.m_source);
#endif
who_e = m_in.m_source;
proc_e = m_in.IO_ENDPT;
grant_id = (cp_grant_id_t) m_in.IO_GRANT;
/* Forword the request message to the drivers. */
switch(m_in.m_type) {
case DEV_OPEN: /* open/close is a noop for filter. */
case DEV_CLOSE: r = OK; break;
case DEV_READ_S: r = do_rdwt(FLT_READ); break;
case DEV_WRITE_S: r = do_rdwt(FLT_WRITE); break;
case DEV_GATHER_S: r = do_vrdwt(FLT_READ); break;
case DEV_SCATTER_S: r = do_vrdwt(FLT_WRITE); break;
case DEV_IOCTL_S: r = do_ioctl(&m_in); break;
default:
printf("Filter: ignoring unknown request %d from %d\n",
m_in.m_type, m_in.m_source);
continue;
}
#if DEBUG2
printf("Filter: replying with code %d\n", r);
#endif
/* Send back reply message. */
m_out.m_type = TASK_REPLY;
m_out.REP_ENDPT = proc_e;
m_out.REP_STATUS = r;
send(who_e, &m_out);
}
return 0;
}
Initialization protocol for system services. SYSLIB CHANGES: - SEF framework now supports a new SEF Init request type from RS. 3 different callbacks are available (init_fresh, init_lu, init_restart) to specify initialization code when a service starts fresh, starts after a live update, or restarts. SYSTEM SERVICE CHANGES: - Initialization code for system services is now enclosed in a callback SEF will automatically call at init time. The return code of the callback will tell RS whether the initialization completed successfully. - Each init callback can access information passed by RS to initialize. As of now, each system service has access to the public entries of RS's system process table to gather all the information required to initialize. This design eliminates many existing or potential races at boot time and provides a uniform initialization interface to system services. The same interface will be reused for the upcoming publish/subscribe model to handle dynamic registration / deregistration of system services. VM CHANGES: - Uniform privilege management for all system services. Every service uses the same call mask format. For boot services, VM copies the call mask from init data. For dynamic services, VM still receives the call mask via rs_set_priv call that will be soon replaced by the upcoming publish/subscribe model. RS CHANGES: - The system process table has been reorganized and split into private entries and public entries. Only the latter ones are exposed to system services. - VM call masks are now entirely configured in rs/table.c - RS has now its own slot in the system process table. Only kernel tasks and user processes not included in the boot image are now left out from the system process table. - RS implements the initialization protocol for system services. - For services in the boot image, RS blocks till initialization is complete and panics when failure is reported back. Services are initialized in their order of appearance in the boot image priv table and RS blocks to implements synchronous initialization for every system service having the flag SF_SYNCH_BOOT set. - For services started dynamically, the initialization protocol is implemented as though it were the first ping for the service. In this case, if the system service fails to report back (or reports failure), RS brings the service down rather than trying to restart it.
2010-01-08 02:20:42 +01:00
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
PRIVATE void sef_local_startup(void)
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fresh);
/* No live update support for now. */
New RS and new signal handling for system processes. UPDATING INFO: 20100317: /usr/src/etc/system.conf updated to ignore default kernel calls: copy it (or merge it) to /etc/system.conf. The hello driver (/dev/hello) added to the distribution: # cd /usr/src/commands/scripts && make clean install # cd /dev && MAKEDEV hello KERNEL CHANGES: - Generic signal handling support. The kernel no longer assumes PM as a signal manager for every process. The signal manager of a given process can now be specified in its privilege slot. When a signal has to be delivered, the kernel performs the lookup and forwards the signal to the appropriate signal manager. PM is the default signal manager for user processes, RS is the default signal manager for system processes. To enable ptrace()ing for system processes, it is sufficient to change the default signal manager to PM. This will temporarily disable crash recovery, though. - sys_exit() is now split into sys_exit() (i.e. exit() for system processes, which generates a self-termination signal), and sys_clear() (i.e. used by PM to ask the kernel to clear a process slot when a process exits). - Added a new kernel call (i.e. sys_update()) to swap two process slots and implement live update. PM CHANGES: - Posix signal handling is no longer allowed for system processes. System signals are split into two fixed categories: termination and non-termination signals. When a non-termination signaled is processed, PM transforms the signal into an IPC message and delivers the message to the system process. When a termination signal is processed, PM terminates the process. - PM no longer assumes itself as the signal manager for system processes. It now makes sure that every system signal goes through the kernel before being actually processes. The kernel will then dispatch the signal to the appropriate signal manager which may or may not be PM. SYSLIB CHANGES: - Simplified SEF init and LU callbacks. - Added additional predefined SEF callbacks to debug crash recovery and live update. - Fixed a temporary ack in the SEF init protocol. SEF init reply is now completely synchronous. - Added SEF signal event type to provide a uniform interface for system processes to deal with signals. A sef_cb_signal_handler() callback is available for system processes to handle every received signal. A sef_cb_signal_manager() callback is used by signal managers to process system signals on behalf of the kernel. - Fixed a few bugs with memory mapping and DS. VM CHANGES: - Page faults and memory requests coming from the kernel are now implemented using signals. - Added a new VM call to swap two process slots and implement live update. - The call is used by RS at update time and in turn invokes the kernel call sys_update(). RS CHANGES: - RS has been reworked with a better functional decomposition. - Better kernel call masks. com.h now defines the set of very basic kernel calls every system service is allowed to use. This makes system.conf simpler and easier to maintain. In addition, this guarantees a higher level of isolation for system libraries that use one or more kernel calls internally (e.g. printf). - RS is the default signal manager for system processes. By default, RS intercepts every signal delivered to every system process. This makes crash recovery possible before bringing PM and friends in the loop. - RS now supports fast rollback when something goes wrong while initializing the new version during a live update. - Live update is now implemented by keeping the two versions side-by-side and swapping the process slots when the old version is ready to update. - Crash recovery is now implemented by keeping the two versions side-by-side and cleaning up the old version only when the recovery process is complete. DS CHANGES: - Fixed a bug when the process doing ds_publish() or ds_delete() is not known by DS. - Fixed the completely broken support for strings. String publishing is now implemented in the system library and simply wraps publishing of memory ranges. Ideally, we should adopt a similar approach for other data types as well. - Test suite fixed. DRIVER CHANGES: - The hello driver has been added to the Minix distribution to demonstrate basic live update and crash recovery functionalities. - Other drivers have been adapted to conform the new SEF interface.
2010-03-17 02:15:29 +01:00
/* Register signal callbacks. */
sef_setcb_signal_handler(sef_cb_signal_handler);
Initialization protocol for system services. SYSLIB CHANGES: - SEF framework now supports a new SEF Init request type from RS. 3 different callbacks are available (init_fresh, init_lu, init_restart) to specify initialization code when a service starts fresh, starts after a live update, or restarts. SYSTEM SERVICE CHANGES: - Initialization code for system services is now enclosed in a callback SEF will automatically call at init time. The return code of the callback will tell RS whether the initialization completed successfully. - Each init callback can access information passed by RS to initialize. As of now, each system service has access to the public entries of RS's system process table to gather all the information required to initialize. This design eliminates many existing or potential races at boot time and provides a uniform initialization interface to system services. The same interface will be reused for the upcoming publish/subscribe model to handle dynamic registration / deregistration of system services. VM CHANGES: - Uniform privilege management for all system services. Every service uses the same call mask format. For boot services, VM copies the call mask from init data. For dynamic services, VM still receives the call mask via rs_set_priv call that will be soon replaced by the upcoming publish/subscribe model. RS CHANGES: - The system process table has been reorganized and split into private entries and public entries. Only the latter ones are exposed to system services. - VM call masks are now entirely configured in rs/table.c - RS has now its own slot in the system process table. Only kernel tasks and user processes not included in the boot image are now left out from the system process table. - RS implements the initialization protocol for system services. - For services in the boot image, RS blocks till initialization is complete and panics when failure is reported back. Services are initialized in their order of appearance in the boot image priv table and RS blocks to implements synchronous initialization for every system service having the flag SF_SYNCH_BOOT set. - For services started dynamically, the initialization protocol is implemented as though it were the first ping for the service. In this case, if the system service fails to report back (or reports failure), RS brings the service down rather than trying to restart it.
2010-01-08 02:20:42 +01:00
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the filter driver. */
int r;
r = parse_arguments(env_argc, env_argv);
if(r != OK) {
printf("Filter: wrong argument!\n");
return 1;
}
if ((buf_array = flt_malloc(BUF_SIZE, NULL, 0)) == NULL)
panic("no memory available");
Initialization protocol for system services. SYSLIB CHANGES: - SEF framework now supports a new SEF Init request type from RS. 3 different callbacks are available (init_fresh, init_lu, init_restart) to specify initialization code when a service starts fresh, starts after a live update, or restarts. SYSTEM SERVICE CHANGES: - Initialization code for system services is now enclosed in a callback SEF will automatically call at init time. The return code of the callback will tell RS whether the initialization completed successfully. - Each init callback can access information passed by RS to initialize. As of now, each system service has access to the public entries of RS's system process table to gather all the information required to initialize. This design eliminates many existing or potential races at boot time and provides a uniform initialization interface to system services. The same interface will be reused for the upcoming publish/subscribe model to handle dynamic registration / deregistration of system services. VM CHANGES: - Uniform privilege management for all system services. Every service uses the same call mask format. For boot services, VM copies the call mask from init data. For dynamic services, VM still receives the call mask via rs_set_priv call that will be soon replaced by the upcoming publish/subscribe model. RS CHANGES: - The system process table has been reorganized and split into private entries and public entries. Only the latter ones are exposed to system services. - VM call masks are now entirely configured in rs/table.c - RS has now its own slot in the system process table. Only kernel tasks and user processes not included in the boot image are now left out from the system process table. - RS implements the initialization protocol for system services. - For services in the boot image, RS blocks till initialization is complete and panics when failure is reported back. Services are initialized in their order of appearance in the boot image priv table and RS blocks to implements synchronous initialization for every system service having the flag SF_SYNCH_BOOT set. - For services started dynamically, the initialization protocol is implemented as though it were the first ping for the service. In this case, if the system service fails to report back (or reports failure), RS brings the service down rather than trying to restart it.
2010-01-08 02:20:42 +01:00
sum_init();
driver_init();
return(OK);
}
New RS and new signal handling for system processes. UPDATING INFO: 20100317: /usr/src/etc/system.conf updated to ignore default kernel calls: copy it (or merge it) to /etc/system.conf. The hello driver (/dev/hello) added to the distribution: # cd /usr/src/commands/scripts && make clean install # cd /dev && MAKEDEV hello KERNEL CHANGES: - Generic signal handling support. The kernel no longer assumes PM as a signal manager for every process. The signal manager of a given process can now be specified in its privilege slot. When a signal has to be delivered, the kernel performs the lookup and forwards the signal to the appropriate signal manager. PM is the default signal manager for user processes, RS is the default signal manager for system processes. To enable ptrace()ing for system processes, it is sufficient to change the default signal manager to PM. This will temporarily disable crash recovery, though. - sys_exit() is now split into sys_exit() (i.e. exit() for system processes, which generates a self-termination signal), and sys_clear() (i.e. used by PM to ask the kernel to clear a process slot when a process exits). - Added a new kernel call (i.e. sys_update()) to swap two process slots and implement live update. PM CHANGES: - Posix signal handling is no longer allowed for system processes. System signals are split into two fixed categories: termination and non-termination signals. When a non-termination signaled is processed, PM transforms the signal into an IPC message and delivers the message to the system process. When a termination signal is processed, PM terminates the process. - PM no longer assumes itself as the signal manager for system processes. It now makes sure that every system signal goes through the kernel before being actually processes. The kernel will then dispatch the signal to the appropriate signal manager which may or may not be PM. SYSLIB CHANGES: - Simplified SEF init and LU callbacks. - Added additional predefined SEF callbacks to debug crash recovery and live update. - Fixed a temporary ack in the SEF init protocol. SEF init reply is now completely synchronous. - Added SEF signal event type to provide a uniform interface for system processes to deal with signals. A sef_cb_signal_handler() callback is available for system processes to handle every received signal. A sef_cb_signal_manager() callback is used by signal managers to process system signals on behalf of the kernel. - Fixed a few bugs with memory mapping and DS. VM CHANGES: - Page faults and memory requests coming from the kernel are now implemented using signals. - Added a new VM call to swap two process slots and implement live update. - The call is used by RS at update time and in turn invokes the kernel call sys_update(). RS CHANGES: - RS has been reworked with a better functional decomposition. - Better kernel call masks. com.h now defines the set of very basic kernel calls every system service is allowed to use. This makes system.conf simpler and easier to maintain. In addition, this guarantees a higher level of isolation for system libraries that use one or more kernel calls internally (e.g. printf). - RS is the default signal manager for system processes. By default, RS intercepts every signal delivered to every system process. This makes crash recovery possible before bringing PM and friends in the loop. - RS now supports fast rollback when something goes wrong while initializing the new version during a live update. - Live update is now implemented by keeping the two versions side-by-side and swapping the process slots when the old version is ready to update. - Crash recovery is now implemented by keeping the two versions side-by-side and cleaning up the old version only when the recovery process is complete. DS CHANGES: - Fixed a bug when the process doing ds_publish() or ds_delete() is not known by DS. - Fixed the completely broken support for strings. String publishing is now implemented in the system library and simply wraps publishing of memory ranges. Ideally, we should adopt a similar approach for other data types as well. - Test suite fixed. DRIVER CHANGES: - The hello driver has been added to the Minix distribution to demonstrate basic live update and crash recovery functionalities. - Other drivers have been adapted to conform the new SEF interface.
2010-03-17 02:15:29 +01:00
/*===========================================================================*
* sef_cb_signal_handler *
*===========================================================================*/
PRIVATE void sef_cb_signal_handler(int signo)
{
/* Only check for termination signal, ignore anything else. */
if (signo != SIGTERM) return;
/* If so, shut down this driver. */
#if DEBUG
printf("Filter: shutdown...\n");
#endif
driver_shutdown();
exit(0);
}