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minix/servers/vfs/misc.c
Thomas Veerman 992799b91f VFS: make all IPC asynchronous 
By decoupling synchronous drivers from VFS, we are a big step closer to
supporting driver crashes under all circumstances. That is, VFS can't
become stuck on IPC with a synchronous driver (e.g., INET) and can
recover from crashing block drivers during open/close/ioctl or during
communication with an FS.

In order to maintain serialized communication with a synchronous driver,
the communication is wrapped by a mutex on a per driver basis (not major
numbers as there can be multiple majors with identical endpoints). Majors
that share a driver endpoint point to a single mutex object.

In order to support crashes from block drivers, the file reopen tactic
had to be changed; first reopen files associated with the crashed
driver, then send the new driver endpoint to FSes. This solves a
deadlock between the FS and the block driver;
  - VFS would send REQ_NEW_DRIVER to an FS, but he FS only receives it
    after retrying the current request to the newly started driver.
  - The block driver would refuse the retried request until all files
    had been reopened.
  - VFS would reopen files only after getting a reply from the initial
    REQ_NEW_DRIVER.

When a character special driver crashes, all associated files have to
be marked invalid and closed (or reopened if flagged as such). However,
they can only be closed if a thread holds exclusive access to it. To
obtain exclusive access, the worker thread (which handles the new driver
endpoint event from DS) schedules a new job to garbage collect invalid
files. This way, we can signal the worker thread that was talking to the
crashed driver and will release exclusive access to a file associated
with the crashed driver and prevent the garbage collecting worker thread
from dead locking on that file.

Also, when a character special driver crashes, RS will unmap the driver
and remap it upon restart. During unmapping, associated files are marked
invalid instead of waiting for an endpoint up event from DS, as that
event might come later than new read/write/select requests and thus
cause confusion in the freshly started driver.

When locking a filp, the usage counters are no longer checked. The usage
counter can legally go down to zero during filp invalidation while there
are locks pending.

DS events are handled by a separate worker thread instead of the main
thread as reopening files could lead to another crash and a stuck thread.
An additional worker thread is then necessary to unlock it.

Finally, with everything asynchronous a race condition in do_select
surfaced. A select entry was only marked in use after succesfully sending
initial select requests to drivers and having to wait. When multiple
select() calls were handled there was opportunity that these entries
were overwritten. This had as effect that some select results were
ignored (and select() remained blocking instead if returning) or do_select
tried to access filps that were not present (because thrown away by
secondary select()). This bug manifested itself with sendrecs, but was
very hard to reproduce. However, it became awfully easy to trigger with
asynsends only.
2012-09-17 11:01:45 +00:00

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/* This file contains a collection of miscellaneous procedures. Some of them
* perform simple system calls. Some others do a little part of system calls
* that are mostly performed by the Memory Manager.
*
* The entry points into this file are
* do_dup: perform the DUP system call
* do_fcntl: perform the FCNTL system call
* do_sync: perform the SYNC system call
* do_fsync: perform the FSYNC system call
* pm_reboot: sync disks and prepare for shutdown
* pm_fork: adjust the tables after PM has performed a FORK system call
* do_exec: handle files with FD_CLOEXEC on after PM has done an EXEC
* do_exit: a process has exited; note that in the tables
* do_set: set uid or gid for some process
* do_revive: revive a process that was waiting for something (e.g. TTY)
* do_svrctl: file system control
* do_getsysinfo: request copy of FS data structure
* pm_dumpcore: create a core dump
*/
#include "fs.h"
#include <fcntl.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <minix/callnr.h>
#include <minix/safecopies.h>
#include <minix/endpoint.h>
#include <minix/com.h>
#include <minix/sysinfo.h>
#include <minix/u64.h>
#include <sys/ptrace.h>
#include <sys/svrctl.h>
#include "file.h"
#include "fproc.h"
#include "scratchpad.h"
#include "dmap.h"
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"
#include "param.h"
#define CORE_NAME "core"
#define CORE_MODE 0777 /* mode to use on core image files */
#if ENABLE_SYSCALL_STATS
unsigned long calls_stats[NCALLS];
#endif
static void free_proc(struct fproc *freed, int flags);
/*
static int dumpcore(int proc_e, struct mem_map *seg_ptr);
static int write_bytes(struct inode *rip, off_t off, char *buf, size_t
bytes);
static int write_seg(struct inode *rip, off_t off, int proc_e, int seg,
off_t seg_off, phys_bytes seg_bytes);
*/
/*===========================================================================*
* do_getsysinfo *
*===========================================================================*/
int do_getsysinfo()
{
vir_bytes src_addr, dst_addr;
size_t len, buf_size;
int what;
what = job_m_in.SI_WHAT;
dst_addr = (vir_bytes) job_m_in.SI_WHERE;
buf_size = (size_t) job_m_in.SI_SIZE;
/* Only su may call do_getsysinfo. This call may leak information (and is not
* stable enough to be part of the API/ABI). In the future, requests from
* non-system processes should be denied.
*/
if (!super_user) return(EPERM);
switch(what) {
case SI_PROC_TAB:
src_addr = (vir_bytes) fproc;
len = sizeof(struct fproc) * NR_PROCS;
break;
case SI_DMAP_TAB:
src_addr = (vir_bytes) dmap;
len = sizeof(struct dmap) * NR_DEVICES;
break;
#if ENABLE_SYSCALL_STATS
case SI_CALL_STATS:
src_addr = (vir_bytes) calls_stats;
len = sizeof(calls_stats);
break;
#endif
default:
return(EINVAL);
}
if (len != buf_size)
return(EINVAL);
return sys_datacopy(SELF, src_addr, who_e, dst_addr, len);
}
/*===========================================================================*
* do_dup *
*===========================================================================*/
int do_dup()
{
/* Perform the dup(fd) or dup2(fd,fd2) system call. These system calls are
* obsolete. In fact, it is not even possible to invoke them using the
* current library because the library routines call fcntl(). They are
* provided to permit old binary programs to continue to run.
*/
int rfd, rfd2;
struct filp *f;
int r = OK;
scratch(fp).file.fd_nr = job_m_in.fd;
rfd2 = job_m_in.fd2;
/* Is the file descriptor valid? */
rfd = scratch(fp).file.fd_nr & ~DUP_MASK; /* kill off dup2 bit, if on */
if ((f = get_filp(rfd, VNODE_READ)) == NULL) return(err_code);
/* Distinguish between dup and dup2. */
if (!(scratch(fp).file.fd_nr & DUP_MASK)) { /* bit not on */
/* dup(fd) */
r = get_fd(0, 0, &rfd2, NULL);
} else {
/* dup2(old_fd, new_fd) */
if (rfd2 < 0 || rfd2 >= OPEN_MAX) {
r = EBADF;
} else if (rfd == rfd2) { /* ignore the call: dup2(x, x) */
r = rfd2;
} else {
/* All is fine, close new_fd if necessary */
unlock_filp(f); /* or it might deadlock on do_close */
(void) close_fd(fp, rfd2); /* cannot fail */
f = get_filp(rfd, VNODE_READ); /* lock old_fd again */
if (f == NULL) return(err_code);
}
}
if (r == OK) {
/* Success. Set up new file descriptors. */
f->filp_count++;
fp->fp_filp[rfd2] = f;
FD_SET(rfd2, &fp->fp_filp_inuse);
r = rfd2;
}
unlock_filp(f);
return(r);
}
/*===========================================================================*
* do_fcntl *
*===========================================================================*/
int do_fcntl()
{
/* Perform the fcntl(fd, request, ...) system call. */
register struct filp *f;
int new_fd, fl, r = OK, fcntl_req, fcntl_argx;
tll_access_t locktype;
scratch(fp).file.fd_nr = job_m_in.fd;
scratch(fp).io.io_buffer = job_m_in.buffer;
scratch(fp).io.io_nbytes = job_m_in.nbytes; /* a.k.a. m_in.request */
fcntl_req = job_m_in.request;
fcntl_argx = job_m_in.addr;
/* Is the file descriptor valid? */
locktype = (fcntl_req == F_FREESP) ? VNODE_WRITE : VNODE_READ;
if ((f = get_filp(scratch(fp).file.fd_nr, locktype)) == NULL)
return(err_code);
switch (fcntl_req) {
case F_DUPFD:
/* This replaces the old dup() system call. */
if (fcntl_argx < 0 || fcntl_argx >= OPEN_MAX) r = EINVAL;
else if ((r = get_fd(fcntl_argx, 0, &new_fd, NULL)) == OK) {
f->filp_count++;
fp->fp_filp[new_fd] = f;
FD_SET(new_fd, &fp->fp_filp_inuse);
r = new_fd;
}
break;
case F_GETFD:
/* Get close-on-exec flag (FD_CLOEXEC in POSIX Table 6-2). */
r = 0;
if (FD_ISSET(scratch(fp).file.fd_nr, &fp->fp_cloexec_set))
r = FD_CLOEXEC;
break;
case F_SETFD:
/* Set close-on-exec flag (FD_CLOEXEC in POSIX Table 6-2). */
if (fcntl_argx & FD_CLOEXEC)
FD_SET(scratch(fp).file.fd_nr, &fp->fp_cloexec_set);
else
FD_CLR(scratch(fp).file.fd_nr, &fp->fp_cloexec_set);
break;
case F_GETFL:
/* Get file status flags (O_NONBLOCK and O_APPEND). */
fl = f->filp_flags & (O_NONBLOCK | O_APPEND | O_ACCMODE);
r = fl;
break;
case F_SETFL:
/* Set file status flags (O_NONBLOCK and O_APPEND). */
fl = O_NONBLOCK | O_APPEND | O_REOPEN;
f->filp_flags = (f->filp_flags & ~fl) | (fcntl_argx & fl);
break;
case F_GETLK:
case F_SETLK:
case F_SETLKW:
/* Set or clear a file lock. */
r = lock_op(f, fcntl_req);
break;
case F_FREESP:
{
/* Free a section of a file */
off_t start, end;
struct flock flock_arg;
signed long offset;
/* Check if it's a regular file. */
if (!S_ISREG(f->filp_vno->v_mode)) r = EINVAL;
else if (!(f->filp_mode & W_BIT)) r = EBADF;
else
/* Copy flock data from userspace. */
r = sys_datacopy(who_e, (vir_bytes) scratch(fp).io.io_buffer,
SELF, (vir_bytes) &flock_arg,
sizeof(flock_arg));
if (r != OK) break;
/* Convert starting offset to signed. */
offset = (signed long) flock_arg.l_start;
/* Figure out starting position base. */
switch(flock_arg.l_whence) {
case SEEK_SET: start = 0; break;
case SEEK_CUR:
if (ex64hi(f->filp_pos) != 0)
panic("do_fcntl: position in file too high");
start = ex64lo(f->filp_pos);
break;
case SEEK_END: start = f->filp_vno->v_size; break;
default: r = EINVAL;
}
if (r != OK) break;
/* Check for overflow or underflow. */
if (offset > 0 && start + offset < start) r = EINVAL;
else if (offset < 0 && start + offset > start) r = EINVAL;
else {
start += offset;
if (start < 0) r = EINVAL;
}
if (r != OK) break;
if (flock_arg.l_len != 0) {
if (start >= f->filp_vno->v_size) r = EINVAL;
else if ((end = start + flock_arg.l_len) <= start) r = EINVAL;
else if (end > f->filp_vno->v_size) end = f->filp_vno->v_size;
} else {
end = 0;
}
if (r != OK) break;
r = req_ftrunc(f->filp_vno->v_fs_e, f->filp_vno->v_inode_nr,start,end);
if (r == OK && flock_arg.l_len == 0)
f->filp_vno->v_size = start;
break;
}
default:
r = EINVAL;
}
unlock_filp(f);
return(r);
}
/*===========================================================================*
* do_sync *
*===========================================================================*/
int do_sync()
{
struct vmnt *vmp;
int r = OK;
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
if (vmp->m_dev != NO_DEV && vmp->m_fs_e != NONE &&
vmp->m_root_node != NULL) {
if ((r = lock_vmnt(vmp, VMNT_EXCL)) != OK)
break;
req_sync(vmp->m_fs_e);
unlock_vmnt(vmp);
}
}
return(r);
}
/*===========================================================================*
* do_fsync *
*===========================================================================*/
int do_fsync()
{
/* Perform the fsync() system call. */
struct filp *rfilp;
struct vmnt *vmp;
dev_t dev;
int r = OK;
scratch(fp).file.fd_nr = job_m_in.fd;
if ((rfilp = get_filp(scratch(fp).file.fd_nr, VNODE_READ)) == NULL)
return(err_code);
dev = rfilp->filp_vno->v_dev;
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
if (vmp->m_dev != NO_DEV && vmp->m_dev == dev &&
vmp->m_fs_e != NONE && vmp->m_root_node != NULL) {
if ((r = lock_vmnt(vmp, VMNT_EXCL)) != OK)
break;
req_sync(vmp->m_fs_e);
unlock_vmnt(vmp);
}
}
unlock_filp(rfilp);
return(r);
}
/*===========================================================================*
* pm_reboot *
*===========================================================================*/
void pm_reboot()
{
/* Perform the VFS side of the reboot call. */
int i;
struct fproc *rfp;
do_sync();
/* Do exit processing for all leftover processes and servers,
* but don't actually exit them (if they were really gone, PM
* will tell us about it).
*/
for (i = 0; i < NR_PROCS; i++) {
rfp = &fproc[i];
/* Don't just free the proc right away, but let it finish what it was
* doing first */
lock_proc(rfp, 0);
if (rfp->fp_endpoint != NONE)
free_proc(rfp, 0);
unlock_proc(rfp);
}
do_sync();
unmount_all();
}
/*===========================================================================*
* pm_fork *
*===========================================================================*/
void pm_fork(endpoint_t pproc, endpoint_t cproc, pid_t cpid)
{
/* Perform those aspects of the fork() system call that relate to files.
* In particular, let the child inherit its parent's file descriptors.
* The parent and child parameters tell who forked off whom. The file
* system uses the same slot numbers as the kernel. Only PM makes this call.
*/
struct fproc *cp, *pp;
int i, parentno, childno;
mutex_t c_fp_lock;
/* Check up-to-dateness of fproc. */
okendpt(pproc, &parentno);
/* PM gives child endpoint, which implies process slot information.
* Don't call isokendpt, because that will verify if the endpoint
* number is correct in fproc, which it won't be.
*/
childno = _ENDPOINT_P(cproc);
if (childno < 0 || childno >= NR_PROCS)
panic("VFS: bogus child for forking: %d", cproc);
if (fproc[childno].fp_pid != PID_FREE)
panic("VFS: forking on top of in-use child: %d", childno);
/* Copy the parent's fproc struct to the child. */
/* However, the mutex variables belong to a slot and must stay the same. */
c_fp_lock = fproc[childno].fp_lock;
fproc[childno] = fproc[parentno];
fproc[childno].fp_lock = c_fp_lock;
/* Increase the counters in the 'filp' table. */
cp = &fproc[childno];
pp = &fproc[parentno];
for (i = 0; i < OPEN_MAX; i++)
if (cp->fp_filp[i] != NULL) cp->fp_filp[i]->filp_count++;
/* Fill in new process and endpoint id. */
cp->fp_pid = cpid;
cp->fp_endpoint = cproc;
/* A forking process never has an outstanding grant, as it isn't blocking on
* I/O. */
if (GRANT_VALID(pp->fp_grant)) {
panic("VFS: fork: pp (endpoint %d) has grant %d\n", pp->fp_endpoint,
pp->fp_grant);
}
if (GRANT_VALID(cp->fp_grant)) {
panic("VFS: fork: cp (endpoint %d) has grant %d\n", cp->fp_endpoint,
cp->fp_grant);
}
/* A child is not a process leader, not being revived, etc. */
cp->fp_flags = FP_NOFLAGS;
/* Record the fact that both root and working dir have another user. */
if (cp->fp_rd) dup_vnode(cp->fp_rd);
if (cp->fp_wd) dup_vnode(cp->fp_wd);
}
/*===========================================================================*
* free_proc *
*===========================================================================*/
static void free_proc(struct fproc *exiter, int flags)
{
int i;
register struct fproc *rfp;
register struct filp *rfilp;
register struct vnode *vp;
dev_t dev;
if (exiter->fp_endpoint == NONE)
panic("free_proc: already free");
if (fp_is_blocked(exiter))
unpause(exiter->fp_endpoint);
/* Loop on file descriptors, closing any that are open. */
for (i = 0; i < OPEN_MAX; i++) {
(void) close_fd(exiter, i);
}
/* Release root and working directories. */
if (exiter->fp_rd) { put_vnode(exiter->fp_rd); exiter->fp_rd = NULL; }
if (exiter->fp_wd) { put_vnode(exiter->fp_wd); exiter->fp_wd = NULL; }
/* The rest of these actions is only done when processes actually exit. */
if (!(flags & FP_EXITING)) return;
exiter->fp_flags |= FP_EXITING;
/* Check if any process is SUSPENDed on this driver.
* If a driver exits, unmap its entries in the dmap table.
* (unmapping has to be done after the first step, because the
* dmap table is used in the first step.)
*/
unsuspend_by_endpt(exiter->fp_endpoint);
dmap_unmap_by_endpt(exiter->fp_endpoint);
worker_stop_by_endpt(exiter->fp_endpoint); /* Unblock waiting threads */
vmnt_unmap_by_endpt(exiter->fp_endpoint); /* Invalidate open files if this
* was an active FS */
/* Invalidate endpoint number for error and sanity checks. */
exiter->fp_endpoint = NONE;
/* If a session leader exits and it has a controlling tty, then revoke
* access to its controlling tty from all other processes using it.
*/
if ((exiter->fp_flags & FP_SESLDR) && exiter->fp_tty != 0) {
dev = exiter->fp_tty;
for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
if(rfp->fp_pid == PID_FREE) continue;
if (rfp->fp_tty == dev) rfp->fp_tty = 0;
for (i = 0; i < OPEN_MAX; i++) {
if ((rfilp = rfp->fp_filp[i]) == NULL) continue;
if (rfilp->filp_mode == FILP_CLOSED) continue;
vp = rfilp->filp_vno;
if (!S_ISCHR(vp->v_mode)) continue;
if ((dev_t) vp->v_sdev != dev) continue;
lock_filp(rfilp, VNODE_READ);
(void) dev_close(dev, rfilp-filp); /* Ignore any errors, even
* SUSPEND. */
rfilp->filp_mode = FILP_CLOSED;
unlock_filp(rfilp);
}
}
}
/* Exit done. Mark slot as free. */
exiter->fp_pid = PID_FREE;
if (exiter->fp_flags & FP_PENDING)
pending--; /* No longer pending job, not going to do it */
exiter->fp_flags = FP_NOFLAGS;
}
/*===========================================================================*
* pm_exit *
*===========================================================================*/
void pm_exit(proc)
int proc;
{
/* Perform the file system portion of the exit(status) system call. */
int exitee_p;
/* Nevertheless, pretend that the call came from the user. */
okendpt(proc, &exitee_p);
fp = &fproc[exitee_p];
free_proc(fp, FP_EXITING);
}
/*===========================================================================*
* pm_setgid *
*===========================================================================*/
void pm_setgid(proc_e, egid, rgid)
int proc_e;
int egid;
int rgid;
{
register struct fproc *tfp;
int slot;
okendpt(proc_e, &slot);
tfp = &fproc[slot];
tfp->fp_effgid = egid;
tfp->fp_realgid = rgid;
}
/*===========================================================================*
* pm_setgroups *
*===========================================================================*/
void pm_setgroups(proc_e, ngroups, groups)
int proc_e;
int ngroups;
gid_t *groups;
{
struct fproc *rfp;
int slot;
okendpt(proc_e, &slot);
rfp = &fproc[slot];
if (ngroups * sizeof(gid_t) > sizeof(rfp->fp_sgroups))
panic("VFS: pm_setgroups: too much data to copy");
if (sys_datacopy(who_e, (vir_bytes) groups, SELF, (vir_bytes) rfp->fp_sgroups,
ngroups * sizeof(gid_t)) == OK) {
rfp->fp_ngroups = ngroups;
} else
panic("VFS: pm_setgroups: datacopy failed");
}
/*===========================================================================*
* pm_setuid *
*===========================================================================*/
void pm_setuid(proc_e, euid, ruid)
int proc_e;
int euid;
int ruid;
{
struct fproc *tfp;
int slot;
okendpt(proc_e, &slot);
tfp = &fproc[slot];
tfp->fp_effuid = euid;
tfp->fp_realuid = ruid;
}
/*===========================================================================*
* do_svrctl *
*===========================================================================*/
int do_svrctl()
{
unsigned int svrctl;
vir_bytes ptr;
svrctl = job_m_in.svrctl_req;
ptr = (vir_bytes) job_m_in.svrctl_argp;
if (((svrctl >> 8) & 0xFF) != 'M') return(EINVAL);
switch (svrctl) {
case VFSSETPARAM:
case VFSGETPARAM:
{
struct sysgetenv sysgetenv;
char search_key[64];
char val[64];
int r, s;
/* Copy sysgetenv structure to VFS */
if (sys_datacopy(who_e, ptr, SELF, (vir_bytes) &sysgetenv,
sizeof(sysgetenv)) != OK)
return(EFAULT);
/* Basic sanity checking */
if (svrctl == VFSSETPARAM) {
if (sysgetenv.keylen <= 0 ||
sysgetenv.keylen > (sizeof(search_key) - 1) ||
sysgetenv.vallen <= 0 ||
sysgetenv.vallen >= sizeof(val)) {
return(EINVAL);
}
}
/* Copy parameter "key" */
if ((s = sys_datacopy(who_e, (vir_bytes) sysgetenv.key,
SELF, (vir_bytes) search_key,
sysgetenv.keylen)) != OK)
return(s);
search_key[sysgetenv.keylen] = '\0'; /* Limit string */
/* Is it a parameter we know? */
if (svrctl == VFSSETPARAM) {
if (!strcmp(search_key, "verbose")) {
int verbose_val;
if ((s = sys_datacopy(who_e,
(vir_bytes) sysgetenv.val, SELF,
(vir_bytes) &val, sysgetenv.vallen)) != OK)
return(s);
val[sysgetenv.vallen] = '\0'; /* Limit string */
verbose_val = atoi(val);
if (verbose_val < 0 || verbose_val > 4) {
return(EINVAL);
}
verbose = verbose_val;
r = OK;
} else {
r = ESRCH;
}
} else { /* VFSGETPARAM */
char small_buf[60];
r = ESRCH;
if (!strcmp(search_key, "print_traces")) {
mthread_stacktraces();
sysgetenv.val = 0;
sysgetenv.vallen = 0;
r = OK;
} else if (!strcmp(search_key, "active_threads")) {
int active = NR_WTHREADS - worker_available();
snprintf(small_buf, sizeof(small_buf) - 1,
"%d", active);
sysgetenv.vallen = strlen(small_buf);
r = OK;
}
if (r == OK) {
if ((s = sys_datacopy(SELF,
(vir_bytes) &sysgetenv, who_e, ptr,
sizeof(sysgetenv))) != OK)
return(s);
if (sysgetenv.val != 0) {
if ((s = sys_datacopy(SELF,
(vir_bytes) small_buf, who_e,
(vir_bytes) sysgetenv.val,
sysgetenv.vallen)) != OK)
return(s);
}
}
}
return(r);
}
default:
return(EINVAL);
}
}
/*===========================================================================*
* pm_dumpcore *
*===========================================================================*/
int pm_dumpcore(endpoint_t proc_e, int csig, vir_bytes exe_name)
{
int slot, r, core_fd;
struct filp *f;
char core_path[PATH_MAX];
char proc_name[PROC_NAME_LEN];
okendpt(proc_e, &slot);
fp = &fproc[slot];
/* open core file */
snprintf(core_path, PATH_MAX, "%s.%d", CORE_NAME, fp->fp_pid);
core_fd = common_open(core_path, O_WRONLY | O_CREAT | O_TRUNC, CORE_MODE);
if (core_fd < 0) return(core_fd);
/* get process' name */
r = sys_datacopy(PM_PROC_NR, exe_name, VFS_PROC_NR, (vir_bytes) proc_name,
PROC_NAME_LEN);
if (r != OK) return(r);
proc_name[PROC_NAME_LEN - 1] = '\0';
if ((f = get_filp(core_fd, VNODE_WRITE)) == NULL) return(EBADF);
write_elf_core_file(f, csig, proc_name);
unlock_filp(f);
(void) close_fd(fp, core_fd); /* ignore failure, we're exiting anyway */
if(csig)
free_proc(fp, FP_EXITING);
return(OK);
}
/*===========================================================================*
* ds_event *
*===========================================================================*/
void *
ds_event(void *arg)
{
char key[DS_MAX_KEYLEN];
char *blkdrv_prefix = "drv.blk.";
char *chrdrv_prefix = "drv.chr.";
u32_t value;
int type, r, is_blk;
endpoint_t owner_endpoint;
struct job my_job;
my_job = *((struct job *) arg);
fp = my_job.j_fp;
/* Get the event and the owner from DS. */
while ((r = ds_check(key, &type, &owner_endpoint)) == OK) {
/* Only check for block and character driver up events. */
if (!strncmp(key, blkdrv_prefix, strlen(blkdrv_prefix))) {
is_blk = TRUE;
} else if (!strncmp(key, chrdrv_prefix, strlen(chrdrv_prefix))) {
is_blk = FALSE;
} else {
continue;
}
if ((r = ds_retrieve_u32(key, &value)) != OK) {
printf("VFS: ds_event: ds_retrieve_u32 failed\n");
break;
}
if (value != DS_DRIVER_UP) continue;
/* Perform up. */
dmap_endpt_up(owner_endpoint, is_blk);
}
if (r != ENOENT) printf("VFS: ds_event: ds_check failed: %d\n", r);
thread_cleanup(NULL);
return(NULL);
}
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