minix/servers/fs/pipe.c

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/* This file deals with the suspension and revival of processes. A process can
* be suspended because it wants to read or write from a pipe and can't, or
* because it wants to read or write from a special file and can't. When a
* process can't continue it is suspended, and revived later when it is able
* to continue.
*
* The entry points into this file are
* do_pipe: perform the PIPE system call
* pipe_check: check to see that a read or write on a pipe is feasible now
* suspend: suspend a process that cannot do a requested read or write
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* release: check to see if a suspended process can be released and do
* it
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* revive: mark a suspended process as able to run again
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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* unsuspend_by_endpt: revive all processes blocking on a given process
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* do_unpause: a signal has been sent to a process; see if it suspended
*/
#include "fs.h"
#include <fcntl.h>
#include <signal.h>
#include <assert.h>
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#include <minix/callnr.h>
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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#include <minix/endpoint.h>
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#include <minix/com.h>
#include <sys/select.h>
#include <sys/time.h>
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#include "file.h"
#include "fproc.h"
#include "inode.h"
#include "param.h"
#include "super.h"
#include "select.h"
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/*===========================================================================*
* do_pipe *
*===========================================================================*/
PUBLIC int do_pipe()
{
/* Perform the pipe(fil_des) system call. */
register struct fproc *rfp;
register struct inode *rip;
int r;
struct filp *fil_ptr0, *fil_ptr1;
int fil_des[2]; /* reply goes here */
/* Acquire two file descriptors. */
rfp = fp;
if ( (r = get_fd(0, R_BIT, &fil_des[0], &fil_ptr0)) != OK) return(r);
rfp->fp_filp[fil_des[0]] = fil_ptr0;
FD_SET(fil_des[0], &rfp->fp_filp_inuse);
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fil_ptr0->filp_count = 1;
if ( (r = get_fd(0, W_BIT, &fil_des[1], &fil_ptr1)) != OK) {
rfp->fp_filp[fil_des[0]] = NIL_FILP;
FD_CLR(fil_des[0], &rfp->fp_filp_inuse);
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fil_ptr0->filp_count = 0;
return(r);
}
rfp->fp_filp[fil_des[1]] = fil_ptr1;
FD_SET(fil_des[1], &rfp->fp_filp_inuse);
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fil_ptr1->filp_count = 1;
/* Make the inode on the pipe device. */
if ( (rip = alloc_inode(root_dev, I_REGULAR) ) == NIL_INODE) {
rfp->fp_filp[fil_des[0]] = NIL_FILP;
FD_CLR(fil_des[0], &rfp->fp_filp_inuse);
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fil_ptr0->filp_count = 0;
rfp->fp_filp[fil_des[1]] = NIL_FILP;
FD_CLR(fil_des[1], &rfp->fp_filp_inuse);
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fil_ptr1->filp_count = 0;
return(err_code);
}
if (read_only(rip) != OK)
panic(__FILE__,"pipe device is read only", NO_NUM);
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rip->i_pipe = I_PIPE;
rip->i_mode &= ~I_REGULAR;
rip->i_mode |= I_NAMED_PIPE; /* pipes and FIFOs have this bit set */
fil_ptr0->filp_ino = rip;
fil_ptr0->filp_flags = O_RDONLY;
dup_inode(rip); /* for double usage */
fil_ptr1->filp_ino = rip;
fil_ptr1->filp_flags = O_WRONLY;
rw_inode(rip, WRITING); /* mark inode as allocated */
m_out.reply_i1 = fil_des[0];
m_out.reply_i2 = fil_des[1];
rip->i_update = ATIME | CTIME | MTIME;
return(OK);
}
/*===========================================================================*
* pipe_check *
*===========================================================================*/
PUBLIC int pipe_check(rip, rw_flag, oflags, bytes, position, canwrite, notouch)
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register struct inode *rip; /* the inode of the pipe */
int rw_flag; /* READING or WRITING */
int oflags; /* flags set by open or fcntl */
register int bytes; /* bytes to be read or written (all chunks) */
register off_t position; /* current file position */
int *canwrite; /* return: number of bytes we can write */
int notouch; /* check only */
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{
/* Pipes are a little different. If a process reads from an empty pipe for
* which a writer still exists, suspend the reader. If the pipe is empty
* and there is no writer, return 0 bytes. If a process is writing to a
* pipe and no one is reading from it, give a broken pipe error.
*/
/* If reading, check for empty pipe. */
if (rw_flag == READING) {
if (position >= rip->i_size) {
/* Process is reading from an empty pipe. */
int r = 0;
if (find_filp(rip, W_BIT) != NIL_FILP) {
/* Writer exists */
if (oflags & O_NONBLOCK) {
r = EAGAIN;
} else {
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if (!notouch)
suspend(XPIPE); /* block reader */
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r = SUSPEND;
}
/* If need be, activate sleeping writers. */
if (susp_count > 0)
release(rip, WRITE, susp_count);
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}
return(r);
}
} else {
/* Process is writing to a pipe. */
if (find_filp(rip, R_BIT) == NIL_FILP) {
/* Tell kernel to generate a SIGPIPE signal. */
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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if (!notouch) {
sys_kill(fp->fp_endpoint, SIGPIPE);
}
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return(EPIPE);
}
if (position + bytes > PIPE_SIZE(rip->i_sp->s_block_size)) {
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if ((oflags & O_NONBLOCK)
&& bytes <= PIPE_SIZE(rip->i_sp->s_block_size))
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return(EAGAIN);
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else if ((oflags & O_NONBLOCK)
&& bytes > PIPE_SIZE(rip->i_sp->s_block_size)) {
if ( (*canwrite = (PIPE_SIZE(rip->i_sp->s_block_size)
- position)) > 0) {
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/* Do a partial write. Need to wakeup reader */
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if (!notouch)
release(rip, READ, susp_count);
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return(1);
} else {
return(EAGAIN);
}
}
if (bytes > PIPE_SIZE(rip->i_sp->s_block_size)) {
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if ((*canwrite = PIPE_SIZE(rip->i_sp->s_block_size)
- position) > 0) {
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/* Do a partial write. Need to wakeup reader
* since we'll suspend ourself in read_write()
*/
if (!notouch)
release(rip, READ, susp_count);
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return(1);
}
}
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if (!notouch)
suspend(XPIPE); /* stop writer -- pipe full */
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return(SUSPEND);
}
/* Writing to an empty pipe. Search for suspended reader. */
if (position == 0 && !notouch)
release(rip, READ, susp_count);
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}
*canwrite = 0;
return(1);
}
/*===========================================================================*
* suspend *
*===========================================================================*/
PUBLIC void suspend(task)
int task; /* who is proc waiting for? (PIPE = pipe) */
{
/* Take measures to suspend the processing of the present system call.
* Store the parameters to be used upon resuming in the process table.
* (Actually they are not used when a process is waiting for an I/O device,
* but they are needed for pipes, and it is not worth making the distinction.)
* The SUSPEND pseudo error should be returned after calling suspend().
*/
if (task == XPIPE || task == XPOPEN) susp_count++;/* #procs susp'ed on pipe*/
fp->fp_suspended = SUSPENDED;
assert(!GRANT_VALID(fp->fp_grant));
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fp->fp_fd = m_in.fd << 8 | call_nr;
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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if(task == NONE)
panic(__FILE__,"suspend on NONE",NO_NUM);
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fp->fp_task = -task;
if (task == XLOCK) {
fp->fp_buffer = (char *) m_in.name1; /* third arg to fcntl() */
fp->fp_nbytes = m_in.request; /* second arg to fcntl() */
} else {
fp->fp_buffer = m_in.buffer; /* for reads and writes */
fp->fp_nbytes = m_in.nbytes;
}
}
/*===========================================================================*
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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* unsuspend_by_endpt *
*===========================================================================*/
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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PUBLIC void unsuspend_by_endpt(int proc_e)
{
struct fproc *rp;
int client = 0;
/* Revive processes waiting for drivers (SUSPENDed) that have
* disappeared with return code EAGAIN.
*/
for (rp = &fproc[0]; rp < &fproc[NR_PROCS]; rp++, client++)
if(rp->fp_pid != PID_FREE &&
rp->fp_suspended == SUSPENDED && rp->fp_task == -proc_e) {
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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revive(rp->fp_endpoint, EAGAIN);
}
/* Revive processes waiting in drivers on select()s
* with EAGAIN too.
*/
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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select_unsuspend_by_endpt(proc_e);
return;
}
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/*===========================================================================*
* release *
*===========================================================================*/
PUBLIC void release(ip, call_nr, count)
register struct inode *ip; /* inode of pipe */
int call_nr; /* READ, WRITE, OPEN or CREAT */
int count; /* max number of processes to release */
{
/* Check to see if any process is hanging on the pipe whose inode is in 'ip'.
* If one is, and it was trying to perform the call indicated by 'call_nr',
* release it.
*/
register struct fproc *rp;
struct filp *f;
/* Trying to perform the call also includes SELECTing on it with that
* operation.
*/
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if (call_nr == READ || call_nr == WRITE) {
int op;
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if (call_nr == READ)
op = SEL_RD;
else
op = SEL_WR;
for(f = &filp[0]; f < &filp[NR_FILPS]; f++) {
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if (f->filp_count < 1 || !(f->filp_pipe_select_ops & op) ||
f->filp_ino != ip)
continue;
select_callback(f, op);
f->filp_pipe_select_ops &= ~op;
}
}
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/* Search the proc table. */
for (rp = &fproc[0]; rp < &fproc[NR_PROCS]; rp++) {
if (rp->fp_pid != PID_FREE && rp->fp_suspended == SUSPENDED &&
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rp->fp_revived == NOT_REVIVING &&
(rp->fp_fd & BYTE) == call_nr &&
rp->fp_filp[rp->fp_fd>>8]->filp_ino == ip) {
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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revive(rp->fp_endpoint, 0);
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susp_count--; /* keep track of who is suspended */
if (--count == 0) return;
}
}
}
/*===========================================================================*
* revive *
*===========================================================================*/
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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PUBLIC void revive(proc_nr_e, returned)
int proc_nr_e; /* process to revive */
int returned; /* if hanging on task, how many bytes read */
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{
/* Revive a previously blocked process. When a process hangs on tty, this
* is the way it is eventually released.
*/
register struct fproc *rfp;
register int task;
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
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int proc_nr;
if(isokendpt(proc_nr_e, &proc_nr) != OK)
return;
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rfp = &fproc[proc_nr];
if (rfp->fp_suspended == NOT_SUSPENDED || rfp->fp_revived == REVIVING)return;
/* The 'reviving' flag only applies to pipes. Processes waiting for TTY get
* a message right away. The revival process is different for TTY and pipes.
* For select and TTY revival, the work is already done, for pipes it is not:
* the proc must be restarted so it can try again.
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*/
task = -rfp->fp_task;
if (task == XPIPE || task == XLOCK) {
/* Revive a process suspended on a pipe or lock. */
rfp->fp_revived = REVIVING;
reviving++; /* process was waiting on pipe or lock */
} else {
rfp->fp_suspended = NOT_SUSPENDED;
if (task == XPOPEN) /* process blocked in open or create */
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
2006-03-03 11:20:58 +01:00
reply(proc_nr_e, rfp->fp_fd>>8);
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else if (task == XSELECT) {
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
2006-03-03 11:20:58 +01:00
reply(proc_nr_e, returned);
} else {
/* Revive a process suspended on TTY or other device.
* Pretend it wants only what there is.
*/
rfp->fp_nbytes = returned;
/* If a grant has been issued by FS for this I/O, revoke
* it again now that I/O is done.
*/
if(GRANT_VALID(rfp->fp_grant)) {
if(cpf_revoke(rfp->fp_grant)) {
panic(__FILE__,"FS: revoke failed for grant",
rfp->fp_grant);
}
rfp->fp_grant = GRANT_INVALID;
}
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
2006-03-03 11:20:58 +01:00
reply(proc_nr_e, returned); /* unblock the process */
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}
}
}
/*===========================================================================*
* do_unpause *
*===========================================================================*/
PUBLIC int do_unpause()
{
2006-05-11 16:57:23 +02:00
/* A signal has been sent to a user who is paused on the file system.
* Abort the system call with the EINTR error message.
*/
int proc_nr_e;
if (who_e != PM_PROC_NR) return(EPERM);
proc_nr_e = m_in.ENDPT;
return unpause(proc_nr_e);
}
/*===========================================================================*
* unpause *
*===========================================================================*/
PUBLIC int unpause(proc_nr_e)
int proc_nr_e;
{
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/* A signal has been sent to a user who is paused on the file system.
* Abort the system call with the EINTR error message.
*/
register struct fproc *rfp;
int proc_nr_p, task, fild, status = EINTR;
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struct filp *f;
dev_t dev;
message mess;
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
2006-03-03 11:20:58 +01:00
okendpt(proc_nr_e, &proc_nr_p);
rfp = &fproc[proc_nr_p];
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if (rfp->fp_suspended == NOT_SUSPENDED) return(OK);
task = -rfp->fp_task;
if (rfp->fp_revived == REVIVING)
{
rfp->fp_revived = NOT_REVIVING;
reviving--;
}
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switch (task) {
case XPIPE: /* process trying to read or write a pipe */
break;
case XLOCK: /* process trying to set a lock with FCNTL */
break;
case XSELECT: /* process blocking on select() */
endpoint-aware conversion of servers. 'who', indicating caller number in pm and fs and some other servers, has been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.). In both PM and FS, isokendpt() convert endpoints to process slot numbers, returning OK if it was a valid and consistent endpoint number. okendpt() does the same but panic()s if it doesn't succeed. (In PM, this is pm_isok..) pm and fs keep their own records of process endpoints in their proc tables, which are needed to make kernel calls about those processes. message field names have changed. fs drivers are endpoints. fs now doesn't try to get out of driver deadlock, as the protocol isn't supposed to let that happen any more. (A warning is printed if ELOCKED is detected though.) fproc[].fp_task (indicating which driver the process is suspended on) became an int. PM and FS now get endpoint numbers of initial boot processes from the kernel. These happen to be the same as the old proc numbers, to let user processes reach them with the old numbers, but FS and PM don't know that. All new processes after INIT, even after the generation number wraps around, get endpoint numbers with generation 1 and higher, so the first instances of the boot processes are the only processes ever to have endpoint numbers in the old proc number range. More return code checks of sys_* functions have been added. IS has become endpoint-aware. Ditched the 'text' and 'data' fields in the kernel dump (which show locations, not sizes, so aren't terribly useful) in favour of the endpoint number. Proc number is still visible. Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got the formatting changed. PM reading segments using rw_seg() has changed - it uses other fields in the message now instead of encoding the segment and process number and fd in the fd field. For that it uses _read_pm() and _write_pm() which to _taskcall()s directly in pm/misc.c. PM now sys_exit()s itself on panic(), instead of sys_abort(). RS also talks in endpoints instead of process numbers.
2006-03-03 11:20:58 +01:00
select_forget(proc_nr_e);
break;
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case XPOPEN: /* process trying to open a fifo */
break;
default: /* process trying to do device I/O (e.g. tty)*/
fild = (rfp->fp_fd >> 8) & BYTE;/* extract file descriptor */
if (fild < 0 || fild >= OPEN_MAX)
panic(__FILE__,"unpause err 2",NO_NUM);
2005-04-21 16:53:53 +02:00
f = rfp->fp_filp[fild];
dev = (dev_t) f->filp_ino->i_zone[0]; /* device hung on */
mess.TTY_LINE = (dev >> MINOR) & BYTE;
mess.IO_ENDPT = rfp->fp_ioproc;
mess.IO_GRANT = (char *) rfp->fp_grant;
2005-04-21 16:53:53 +02:00
/* Tell kernel R or W. Mode is from current call, not open. */
mess.COUNT = (rfp->fp_fd & BYTE) == READ ? R_BIT : W_BIT;
mess.m_type = CANCEL;
fp = rfp; /* hack - ctty_io uses fp */
(*dmap[(dev >> MAJOR) & BYTE].dmap_io)(task, &mess);
status = mess.REP_STATUS;
if(status == EAGAIN) status = EINTR;
if(GRANT_VALID(rfp->fp_grant)) {
if(cpf_revoke(rfp->fp_grant)) {
panic(__FILE__,"FS: revoke failed for grant (cancel)",
rfp->fp_grant);
}
rfp->fp_grant = GRANT_INVALID;
}
2005-04-21 16:53:53 +02:00
}
rfp->fp_suspended = NOT_SUSPENDED;
reply(proc_nr_e, status); /* signal interrupted call */
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return(OK);
}
/*===========================================================================*
* select_request_pipe *
*===========================================================================*/
PUBLIC int select_request_pipe(struct filp *f, int *ops, int block)
{
int orig_ops, r = 0, err, canwrite;
orig_ops = *ops;
if ((*ops & (SEL_RD|SEL_ERR))) {
2005-09-11 18:45:46 +02:00
if ((err = pipe_check(f->filp_ino, READING, 0,
1, f->filp_pos, &canwrite, 1)) != SUSPEND)
r |= SEL_RD;
if (err < 0 && err != SUSPEND)
r |= SEL_ERR;
}
if ((*ops & (SEL_WR|SEL_ERR))) {
2005-09-11 18:45:46 +02:00
if ((err = pipe_check(f->filp_ino, WRITING, 0,
1, f->filp_pos, &canwrite, 1)) != SUSPEND)
r |= SEL_WR;
if (err < 0 && err != SUSPEND)
r |= SEL_ERR;
}
/* Some options we collected might not be requested. */
*ops = r & orig_ops;
if (!*ops && block) {
f->filp_pipe_select_ops |= orig_ops;
}
return SEL_OK;
}
/*===========================================================================*
* select_match_pipe *
*===========================================================================*/
PUBLIC int select_match_pipe(struct filp *f)
{
/* recognize either pipe or named pipe (FIFO) */
2005-09-11 18:45:46 +02:00
if (f && f->filp_ino && (f->filp_ino->i_mode & I_NAMED_PIPE))
return 1;
return 0;
}