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minix/servers/vfs/device.c
Thomas Veerman 958b25be50 - Introduce support for sticky bit. 
- Revise VFS-FS protocol and update VFS/MFS/ISOFS accordingly.
- Clean up MFS by removing old, dead code (backwards compatibility is broken by
  the new VFS-FS protocol, anyway) and rewrite other parts. Also, make sure all
  functions have proper banners and prototypes.
- VFS should always provide a (syntactically) valid path to the FS; no need for
  the FS to do sanity checks when leaving/entering mount points.
- Fix several bugs in MFS:
  - Several path lookup bugs in MFS.
  - A link can be too big for the path buffer.
  - A mountpoint can become inaccessible when the creation of a new inode
    fails, because the inode already exists and is a mountpoint.
- Introduce support for supplemental groups.
- Add test 46 to test supplemental group functionality (and removed obsolete
  suppl. tests from test 2).
- Clean up VFS (not everything is done yet).
- ISOFS now opens device read-only. This makes the -r flag in the mount command
  unnecessary (but will still report to be mounted read-write).
- Introduce PipeFS. PipeFS is a new FS that handles all anonymous and
  named pipes. However, named pipes still reside on the (M)FS, as they are part
  of the file system on disk. To make this work VFS now has a concept of
  'mapped' inodes, which causes read, write, truncate and stat requests to be
  redirected to the mapped FS, and all other requests to the original FS.
2009-12-20 20:27:14 +00:00

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/* When a needed block is not in the cache, it must be fetched from the disk.
* Special character files also require I/O. The routines for these are here.
*
* The entry points in this file are:
* dev_open: FS opens a device
* dev_close: FS closes a device
* dev_io: FS does a read or write on a device
* dev_status: FS processes callback request alert
* gen_opcl: generic call to a task to perform an open/close
* gen_io: generic call to a task to perform an I/O operation
* no_dev: open/close processing for devices that don't exist
* no_dev_io: i/o processing for devices that don't exist
* tty_opcl: perform tty-specific processing for open/close
* ctty_opcl: perform controlling-tty-specific processing for open/close
* ctty_io: perform controlling-tty-specific processing for I/O
* do_ioctl: perform the IOCTL system call
* do_setsid: perform the SETSID system call (FS side)
*/
#include "fs.h"
#include <fcntl.h>
#include <assert.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/endpoint.h>
#include <minix/ioctl.h>
#include <minix/u64.h>
#include "file.h"
#include "fproc.h"
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"
#include "param.h"
#define ELEMENTS(a) (sizeof(a)/sizeof((a)[0]))
FORWARD _PROTOTYPE( int safe_io_conversion, (endpoint_t, cp_grant_id_t *,
int *, cp_grant_id_t *, int,
endpoint_t *, void **, int *,
vir_bytes, u32_t *) );
FORWARD _PROTOTYPE( void safe_io_cleanup, (cp_grant_id_t, cp_grant_id_t *,
int) );
FORWARD _PROTOTYPE( void restart_reopen, (int maj) );
extern int dmap_size;
PRIVATE int dummyproc;
/*===========================================================================*
* dev_open *
*===========================================================================*/
PUBLIC int dev_open(dev, proc, flags)
dev_t dev; /* device to open */
int proc; /* process to open for */
int flags; /* mode bits and flags */
{
int major, r;
struct dmap *dp;
/* Determine the major device number call the device class specific
* open/close routine. (This is the only routine that must check the
* device number for being in range. All others can trust this check.)
*/
major = (dev >> MAJOR) & BYTE;
if (major >= NR_DEVICES) major = 0;
dp = &dmap[major];
if (dp->dmap_driver == NONE) return(ENXIO);
r = (*dp->dmap_opcl)(DEV_OPEN, dev, proc, flags);
return(r);
}
/*===========================================================================*
* dev_reopen *
*===========================================================================*/
PUBLIC int dev_reopen(dev, filp_no, flags)
dev_t dev; /* device to open */
int filp_no; /* filp to reopen for */
int flags; /* mode bits and flags */
{
int major, r;
struct dmap *dp;
/* Determine the major device number call the device class specific
* open/close routine. (This is the only routine that must check the
* device number for being in range. All others can trust this check.)
*/
major = (dev >> MAJOR) & BYTE;
if (major >= NR_DEVICES) major = 0;
dp = &dmap[major];
if (dp->dmap_driver == NONE) return(ENXIO);
r = (*dp->dmap_opcl)(DEV_REOPEN, dev, filp_no, flags);
if (r == OK) panic(__FILE__,"OK on reopen from", dp->dmap_driver);
if (r == SUSPEND) r = OK;
return(r);
}
/*===========================================================================*
* dev_close *
*===========================================================================*/
PUBLIC int dev_close(dev, filp_no)
dev_t dev; /* device to close */
int filp_no;
{
int r;
/* See if driver is roughly valid. */
if (dmap[(dev >> MAJOR)].dmap_driver == NONE) return(ENXIO);
r = (*dmap[(dev >> MAJOR) & BYTE].dmap_opcl)(DEV_CLOSE, dev, filp_no, 0);
return(r);
}
/*===========================================================================*
* suspended_ep *
*===========================================================================*/
endpoint_t suspended_ep(endpoint_t driver, cp_grant_id_t g)
{
/* A process is suspended on a driver for which FS issued
* a grant. Find out which process it was.
*/
struct fproc *rfp;
for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
if(rfp->fp_pid == PID_FREE) continue;
if(rfp->fp_blocked_on == FP_BLOCKED_ON_OTHER &&
rfp->fp_task == driver && rfp->fp_grant == g)
return rfp->fp_endpoint;
}
return(NONE);
}
/*===========================================================================*
* dev_status *
*===========================================================================*/
PUBLIC void dev_status(message *m)
{
message st;
int d, get_more = 1;
endpoint_t endpt;
for(d = 0; d < NR_DEVICES; d++)
if (dmap[d].dmap_driver != NONE && dmap[d].dmap_driver == m->m_source)
break;
if (d >= NR_DEVICES) return;
if (dmap[d].dmap_async_driver) {
printf("dev_status: not doing dev_status for async driver %d\n",
m->m_source);
return;
}
do {
int r;
st.m_type = DEV_STATUS;
if ((r = sendrec(m->m_source, &st)) != OK) {
printf("DEV_STATUS failed to %d: %d\n", m->m_source, r);
if (r == EDEADSRCDST) return;
if (r == EDSTDIED) return;
if (r == ESRCDIED) return;
panic(__FILE__,"couldn't sendrec for DEV_STATUS", r);
}
switch(st.m_type) {
case DEV_REVIVE:
endpt = st.REP_ENDPT;
if(endpt == FS_PROC_NR) {
endpt = suspended_ep(m->m_source,
st.REP_IO_GRANT);
if(endpt == NONE) {
printf("FS: proc with grant %d"
" from %d not found (revive)\n",
st.REP_IO_GRANT, st.m_source);
continue;
}
}
revive(endpt, st.REP_STATUS);
break;
case DEV_IO_READY:
select_notified(d, st.DEV_MINOR,
st.DEV_SEL_OPS);
break;
default:
printf("FS: unrecognized reply %d to "
"DEV_STATUS\n", st.m_type);
/* Fall through. */
case DEV_NO_STATUS:
get_more = 0;
break;
}
} while(get_more);
return;
}
/*===========================================================================*
* safe_io_conversion *
*===========================================================================*/
PRIVATE int safe_io_conversion(driver, gid, op, gids, gids_size,
io_ept, buf, vec_grants, bytes, pos_lo)
endpoint_t driver;
cp_grant_id_t *gid;
int *op;
cp_grant_id_t *gids;
int gids_size;
endpoint_t *io_ept;
void **buf;
int *vec_grants;
vir_bytes bytes;
u32_t *pos_lo;
{
int access = 0, size, j;
iovec_t *v;
static iovec_t new_iovec[NR_IOREQS];
/* Number of grants allocated in vector I/O. */
*vec_grants = 0;
/* Driver can handle it - change request to a safe one. */
*gid = GRANT_INVALID;
switch(*op) {
case VFS_DEV_READ:
case VFS_DEV_WRITE:
/* Change to safe op. */
*op = *op == VFS_DEV_READ ? DEV_READ_S : DEV_WRITE_S;
*gid = cpf_grant_magic(driver, *io_ept, (vir_bytes) *buf, bytes,
*op == DEV_READ_S ? CPF_WRITE : CPF_READ);
if (*gid < 0)
panic(__FILE__, "cpf_grant_magic of buffer failed\n", NO_NUM);
break;
case VFS_DEV_GATHER:
case VFS_DEV_SCATTER:
/* Change to safe op. */
*op = *op == VFS_DEV_GATHER ? DEV_GATHER_S : DEV_SCATTER_S;
/* Grant access to my new i/o vector. */
*gid = cpf_grant_direct(driver, (vir_bytes) new_iovec,
bytes * sizeof(iovec_t), CPF_READ|CPF_WRITE);
if (*gid < 0)
panic(__FILE__, "cpf_grant_direct of vector failed", NO_NUM);
v = (iovec_t *) *buf;
/* Grant access to i/o buffers. */
for(j = 0; j < bytes; j++) {
if(j >= NR_IOREQS) panic(__FILE__, "vec too big", bytes);
new_iovec[j].iov_addr =
gids[j] =
cpf_grant_direct(driver, (vir_bytes) v[j].iov_addr, v[j].iov_size,
*op == DEV_GATHER_S ? CPF_WRITE : CPF_READ);
if(!GRANT_VALID(gids[j]))
panic(__FILE__, "grant to iovec buf failed", NO_NUM);
new_iovec[j].iov_size = v[j].iov_size;
(*vec_grants)++;
}
/* Set user's vector to the new one. */
*buf = new_iovec;
break;
case VFS_DEV_IOCTL:
*pos_lo = *io_ept; /* Old endpoint in POSITION field. */
*op = DEV_IOCTL_S;
if(_MINIX_IOCTL_IOR(m_in.REQUEST)) access |= CPF_WRITE;
if(_MINIX_IOCTL_IOW(m_in.REQUEST)) access |= CPF_READ;
if(_MINIX_IOCTL_BIG(m_in.REQUEST))
size = _MINIX_IOCTL_SIZE_BIG(m_in.REQUEST);
else
size = _MINIX_IOCTL_SIZE(m_in.REQUEST);
/* Do this even if no I/O happens with the ioctl, in
* order to disambiguate requests with DEV_IOCTL_S.
*/
*gid = cpf_grant_magic(driver, *io_ept, (vir_bytes) *buf, size,
access);
if (*gid < 0)
panic(__FILE__, "cpf_grant_magic failed (ioctl)\n", NO_NUM);
break;
case VFS_DEV_SELECT:
*op = DEV_SELECT;
break;
default:
panic(__FILE__,"safe_io_conversion: unknown operation", *op);
}
/* If we have converted to a safe operation, I/O
* endpoint becomes FS if it wasn't already.
*/
if(GRANT_VALID(*gid)) {
*io_ept = FS_PROC_NR;
return 1;
}
/* Not converted to a safe operation (because there is no
* copying involved in this operation).
*/
return 0;
}
/*===========================================================================*
* safe_io_cleanup *
*===========================================================================*/
PRIVATE void safe_io_cleanup(gid, gids, gids_size)
cp_grant_id_t gid;
cp_grant_id_t *gids;
int gids_size;
{
/* Free resources (specifically, grants) allocated by safe_io_conversion(). */
int j;
cpf_revoke(gid);
for(j = 0; j < gids_size; j++)
cpf_revoke(gids[j]);
}
/*===========================================================================*
* dev_io *
*===========================================================================*/
PUBLIC int dev_io(op, dev, proc_e, buf, pos, bytes, flags, suspend_reopen)
int op; /* DEV_READ, DEV_WRITE, DEV_IOCTL, etc. */
dev_t dev; /* major-minor device number */
int proc_e; /* in whose address space is buf? */
void *buf; /* virtual address of the buffer */
u64_t pos; /* byte position */
int bytes; /* how many bytes to transfer */
int flags; /* special flags, like O_NONBLOCK */
int suspend_reopen; /* Just suspend the process */
{
/* Read or write from a device. The parameter 'dev' tells which one. */
struct dmap *dp;
u32_t pos_lo, pos_high;
message dev_mess;
cp_grant_id_t gid = GRANT_INVALID;
static cp_grant_id_t gids[NR_IOREQS];
int vec_grants = 0, orig_op, safe;
void *buf_used;
endpoint_t ioproc;
pos_lo= ex64lo(pos);
pos_high= ex64hi(pos);
/* Determine task dmap. */
dp = &dmap[(dev >> MAJOR) & BYTE];
orig_op = op;
/* See if driver is roughly valid. */
if (dp->dmap_driver == NONE) {
printf("FS: dev_io: no driver for dev %x\n", dev);
return(ENXIO);
}
if (suspend_reopen) {
/* Suspend user. */
fp->fp_grant = GRANT_INVALID;
fp->fp_ioproc = NONE;
wait_for(dp->dmap_driver);
fp->fp_flags |= SUSP_REOPEN;
return(SUSPEND);
}
if(isokendpt(dp->dmap_driver, &dummyproc) != OK) {
printf("FS: dev_io: old driver for dev %x (%d)\n",dev,dp->dmap_driver);
return(ENXIO);
}
/* By default, these are right. */
dev_mess.IO_ENDPT = proc_e;
dev_mess.ADDRESS = buf;
/* Convert DEV_* to DEV_*_S variants. */
buf_used = buf;
safe = safe_io_conversion(dp->dmap_driver, &gid, &op, gids, NR_IOREQS,
(endpoint_t*) &dev_mess.IO_ENDPT, &buf_used,
&vec_grants, bytes, &pos_lo);
if(buf != buf_used)
panic(__FILE__,"dev_io: safe_io_conversion changed buffer", NO_NUM);
/* If the safe conversion was done, set the ADDRESS to
* the grant id.
*/
if(safe) dev_mess.IO_GRANT = (char *) gid;
/* Set up the rest of the message passed to task. */
dev_mess.m_type = op;
dev_mess.DEVICE = (dev >> MINOR) & BYTE;
dev_mess.POSITION = pos_lo;
dev_mess.COUNT = bytes;
dev_mess.HIGHPOS = pos_high;
/* This will be used if the i/o is suspended. */
ioproc = dev_mess.IO_ENDPT;
/* Call the task. */
(*dp->dmap_io)(dp->dmap_driver, &dev_mess);
if(dp->dmap_driver == NONE) {
/* Driver has vanished. */
printf("Driver gone?\n");
if(safe) safe_io_cleanup(gid, gids, vec_grants);
return(EIO);
}
/* Task has completed. See if call completed. */
if (dev_mess.REP_STATUS == SUSPEND) {
if(vec_grants > 0) panic(__FILE__,"SUSPEND on vectored i/o", NO_NUM);
/* fp is uninitialized at init time. */
if(!fp) panic(__FILE__,"SUSPEND on NULL fp", NO_NUM);
if ((flags & O_NONBLOCK) && !dp->dmap_async_driver) {
/* Not supposed to block. */
dev_mess.m_type = CANCEL;
dev_mess.IO_ENDPT = ioproc;
dev_mess.IO_GRANT = (char *) gid;
/* This R_BIT/W_BIT check taken from suspend()/unpause()
* logic. Mode is expected in the COUNT field.
*/
dev_mess.COUNT = 0;
if (call_nr == READ) dev_mess.COUNT = R_BIT;
else if (call_nr == WRITE) dev_mess.COUNT = W_BIT;
dev_mess.DEVICE = (dev >> MINOR) & BYTE;
(*dp->dmap_io)(dp->dmap_driver, &dev_mess);
if (dev_mess.REP_STATUS == EINTR) dev_mess.REP_STATUS = EAGAIN;
} else {
/* select() will do suspending itself. */
if(op != DEV_SELECT) {
/* Suspend user. */
wait_for(dp->dmap_driver);
}
assert(!GRANT_VALID(fp->fp_grant));
fp->fp_grant = gid; /* revoke this when unsuspended. */
fp->fp_ioproc = ioproc;
if (flags & O_NONBLOCK) {
/* Not supposed to block, send cancel message */
dev_mess.m_type = CANCEL;
dev_mess.IO_ENDPT = ioproc;
dev_mess.IO_GRANT = (char *) gid;
/* This R_BIT/W_BIT check taken from suspend()/unpause()
* logic. Mode is expected in the COUNT field.
*/
dev_mess.COUNT = 0;
if(call_nr == READ) dev_mess.COUNT = R_BIT;
else if(call_nr == WRITE) dev_mess.COUNT = W_BIT;
dev_mess.DEVICE = (dev >> MINOR) & BYTE;
(*dp->dmap_io)(dp->dmap_driver, &dev_mess);
/* Should do something about EINTR -> EAGAIN mapping */
}
return(SUSPEND);
}
}
/* No suspend, or cancelled suspend, so I/O is over and can be cleaned up. */
if(safe) safe_io_cleanup(gid, gids, vec_grants);
return(dev_mess.REP_STATUS);
}
/*===========================================================================*
* gen_opcl *
*===========================================================================*/
PUBLIC int gen_opcl(op, dev, proc_e, flags)
int op; /* operation, DEV_OPEN or DEV_CLOSE */
dev_t dev; /* device to open or close */
int proc_e; /* process to open/close for */
int flags; /* mode bits and flags */
{
/* Called from the dmap struct in table.c on opens & closes of special files.*/
int r;
struct dmap *dp;
message dev_mess;
/* Determine task dmap. */
dp = &dmap[(dev >> MAJOR) & BYTE];
dev_mess.m_type = op;
dev_mess.DEVICE = (dev >> MINOR) & BYTE;
dev_mess.IO_ENDPT = proc_e;
dev_mess.COUNT = flags;
if (dp->dmap_driver == NONE) {
printf("FS: gen_opcl: no driver for dev %x\n", dev);
return(ENXIO);
}
/* Call the task. */
r= (*dp->dmap_io)(dp->dmap_driver, &dev_mess);
if (r != OK) return(r);
return(dev_mess.REP_STATUS);
}
/*===========================================================================*
* tty_opcl *
*===========================================================================*/
PUBLIC int tty_opcl(op, dev, proc_e, flags)
int op; /* operation, DEV_OPEN or DEV_CLOSE */
dev_t dev; /* device to open or close */
int proc_e; /* process to open/close for */
int flags; /* mode bits and flags */
{
/* This procedure is called from the dmap struct on tty open/close. */
int r;
register struct fproc *rfp;
/* Add O_NOCTTY to the flags if this process is not a session leader, or
* if it already has a controlling tty, or if it is someone elses
* controlling tty.
*/
if (!fp->fp_sesldr || fp->fp_tty != 0) {
flags |= O_NOCTTY;
} else {
for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
if(rfp->fp_pid == PID_FREE) continue;
if (rfp->fp_tty == dev) flags |= O_NOCTTY;
}
}
r = gen_opcl(op, dev, proc_e, flags);
/* Did this call make the tty the controlling tty? */
if (r == 1) {
fp->fp_tty = dev;
r = OK;
}
return(r);
}
/*===========================================================================*
* ctty_opcl *
*===========================================================================*/
PUBLIC int ctty_opcl(op, dev, proc_e, flags)
int op; /* operation, DEV_OPEN or DEV_CLOSE */
dev_t dev; /* device to open or close */
int proc_e; /* process to open/close for */
int flags; /* mode bits and flags */
{
/* This procedure is called from the dmap struct in table.c on opening/closing
* /dev/tty, the magic device that translates to the controlling tty.
*/
return(fp->fp_tty == 0 ? ENXIO : OK);
}
/*===========================================================================*
* pm_setsid *
*===========================================================================*/
PUBLIC void pm_setsid(proc_e)
int proc_e;
{
/* Perform the FS side of the SETSID call, i.e. get rid of the controlling
* terminal of a process, and make the process a session leader.
*/
register struct fproc *rfp;
int slot;
/* Make the process a session leader with no controlling tty. */
okendpt(proc_e, &slot);
rfp = &fproc[slot];
rfp->fp_sesldr = TRUE;
rfp->fp_tty = 0;
}
/*===========================================================================*
* do_ioctl *
*===========================================================================*/
PUBLIC int do_ioctl()
{
/* Perform the ioctl(ls_fd, request, argx) system call (uses m2 fmt). */
int suspend_reopen;
struct filp *f;
register struct vnode *vp;
dev_t dev;
if ((f = get_filp(m_in.ls_fd)) == NIL_FILP) return(err_code);
vp = f->filp_vno; /* get vnode pointer */
if ((vp->v_mode & I_TYPE) != I_CHAR_SPECIAL &&
(vp->v_mode & I_TYPE) != I_BLOCK_SPECIAL) return(ENOTTY);
suspend_reopen= (f->filp_state != FS_NORMAL);
dev = (dev_t) vp->v_sdev;
return dev_io(VFS_DEV_IOCTL, dev, who_e, m_in.ADDRESS, cvu64(0),
m_in.REQUEST, f->filp_flags, suspend_reopen);
}
/*===========================================================================*
* gen_io *
*===========================================================================*/
PUBLIC int gen_io(task_nr, mess_ptr)
int task_nr; /* which task to call */
message *mess_ptr; /* pointer to message for task */
{
/* All file system I/O ultimately comes down to I/O on major/minor device
* pairs. These lead to calls on the following routines via the dmap table.
*/
int r, proc_e;
if(task_nr == SYSTEM) printf("VFS: sending %d to SYSTEM\n", mess_ptr->m_type);
proc_e = mess_ptr->IO_ENDPT;
r = sendrec(task_nr, mess_ptr);
if (r != OK) {
if (r == EDEADSRCDST || r == EDSTDIED || r == ESRCDIED) {
printf("fs: dead driver %d\n", task_nr);
dmap_unmap_by_endpt(task_nr);
return(r);
}
if (r == ELOCKED) {
printf("fs: ELOCKED talking to %d\n", task_nr);
return(r);
}
panic(__FILE__,"call_task: can't send/receive", r);
}
/* Did the process we did the sendrec() for get a result? */
if (mess_ptr->REP_ENDPT != proc_e) {
printf("fs: strange device reply from %d, type = %d, proc = %d "
"(not %d) (2) ignored\n", mess_ptr->m_source, mess_ptr->m_type,
proc_e, mess_ptr->REP_ENDPT);
return(EIO);
}
return(OK);
}
/*===========================================================================*
* asyn_io *
*===========================================================================*/
PUBLIC int asyn_io(task_nr, mess_ptr)
int task_nr; /* which task to call */
message *mess_ptr; /* pointer to message for task */
{
/* All file system I/O ultimately comes down to I/O on major/minor device
* pairs. These lead to calls on the following routines via the dmap table.
*/
int r, proc_e;
proc_e = mess_ptr->IO_ENDPT;
r = asynsend(task_nr, mess_ptr);
if (r != OK) panic(__FILE__, "asyn_io: asynsend failed", r);
/* Fake a SUSPEND */
mess_ptr->REP_STATUS = SUSPEND;
return(OK);
}
/*===========================================================================*
* ctty_io *
*===========================================================================*/
PUBLIC int ctty_io(task_nr, mess_ptr)
int task_nr; /* not used - for compatibility with dmap_t */
message *mess_ptr; /* pointer to message for task */
{
/* This routine is only called for one device, namely /dev/tty. Its job
* is to change the message to use the controlling terminal, instead of the
* major/minor pair for /dev/tty itself.
*/
struct dmap *dp;
if (fp->fp_tty == 0) {
/* No controlling tty present anymore, return an I/O error. */
mess_ptr->REP_STATUS = EIO;
} else {
/* Substitute the controlling terminal device. */
dp = &dmap[(fp->fp_tty >> MAJOR) & BYTE];
mess_ptr->DEVICE = (fp->fp_tty >> MINOR) & BYTE;
if (dp->dmap_driver == NONE) {
printf("FS: ctty_io: no driver for dev\n");
return(EIO);
}
if(isokendpt(dp->dmap_driver, &dummyproc) != OK) {
printf("FS: ctty_io: old driver %d\n", dp->dmap_driver);
return(EIO);
}
(*dp->dmap_io)(dp->dmap_driver, mess_ptr);
}
return(OK);
}
/*===========================================================================*
* no_dev *
*===========================================================================*/
PUBLIC int no_dev(op, dev, proc, flags)
int op; /* operation, DEV_OPEN or DEV_CLOSE */
dev_t dev; /* device to open or close */
int proc; /* process to open/close for */
int flags; /* mode bits and flags */
{
/* Called when opening a nonexistent device. */
return(ENODEV);
}
/*===========================================================================*
* no_dev_io *
*===========================================================================*/
PUBLIC int no_dev_io(int proc, message *m)
{
/* Called when doing i/o on a nonexistent device. */
printf("VFS: I/O on unmapped device number\n");
return(EIO);
}
/*===========================================================================*
* clone_opcl *
*===========================================================================*/
PUBLIC int clone_opcl(op, dev, proc_e, flags)
int op; /* operation, DEV_OPEN or DEV_CLOSE */
dev_t dev; /* device to open or close */
int proc_e; /* process to open/close for */
int flags; /* mode bits and flags */
{
/* Some devices need special processing upon open. Such a device is "cloned",
* i.e. on a succesful open it is replaced by a new device with a new unique
* minor device number. This new device number identifies a new object (such
* as a new network connection) that has been allocated within a task.
*/
struct dmap *dp;
int r, minor;
message dev_mess;
/* Determine task dmap. */
dp = &dmap[(dev >> MAJOR) & BYTE];
minor = (dev >> MINOR) & BYTE;
dev_mess.m_type = op;
dev_mess.DEVICE = minor;
dev_mess.IO_ENDPT = proc_e;
dev_mess.COUNT = flags;
if (dp->dmap_driver == NONE) {
printf("VFS clone_opcl: no driver for dev %x\n", dev);
return(ENXIO);
}
if(isokendpt(dp->dmap_driver, &dummyproc) != OK) {
printf("VFS clone_opcl: bad driver endpoint for dev %x (%d)\n", dev,
dp->dmap_driver);
return(ENXIO);
}
/* Call the task. */
r = (*dp->dmap_io)(dp->dmap_driver, &dev_mess);
if (r != OK) return(r);
if (op == DEV_OPEN && dev_mess.REP_STATUS >= 0) {
if (dev_mess.REP_STATUS != minor) {
struct vnode *vp;
struct vmnt *vmp;
struct node_details res;
/* A new minor device number has been returned.
* Request the root FS to create a temporary device file to
* hold it.
*/
/* Device number of the new device. */
dev = (dev & ~(BYTE << MINOR)) | (dev_mess.REP_STATUS << MINOR);
/* Issue request */
r = req_newnode(ROOT_FS_E, fp->fp_effuid, fp->fp_effgid,
ALL_MODES | I_CHAR_SPECIAL, dev, &res);
if (r != OK) {
(void) clone_opcl(DEV_CLOSE, dev, proc_e, 0);
return r;
}
/* Drop old node and use the new values */
vp = fp->fp_filp[m_in.fd]->filp_vno;
put_vnode(vp);
if ((vp = get_free_vnode()) == NIL_VNODE)
vp = fp->fp_filp[m_in.fd]->filp_vno;
vp->v_fs_e = res.fs_e;
if ((vmp = find_vmnt(vp->v_fs_e)) == NIL_VMNT)
printf("VFS clone_opcl: no vmnt found\n");
vp->v_vmnt = vmp;
vp->v_dev = vmp->m_dev;
vp->v_fs_e = res.fs_e;
vp->v_inode_nr = res.inode_nr;
vp->v_mode = res.fmode;
vp->v_sdev = dev;
vp->v_fs_count = 1;
vp->v_ref_count = 1;
fp->fp_filp[m_in.fd]->filp_vno = vp;
}
dev_mess.REP_STATUS = OK;
}
return(dev_mess.REP_STATUS);
}
/*===========================================================================*
* dev_up *
*===========================================================================*/
PUBLIC void dev_up(int maj)
{
/* A new device driver has been mapped in. This function
* checks if any filesystems are mounted on it, and if so,
* dev_open()s them so the filesystem can be reused.
*/
int r, new_driver_e, needs_reopen, fd_nr;
struct filp *fp;
struct vmnt *vmp;
struct fproc *rfp;
struct vnode *vp;
message m;
/* Open a device once for every filp that's opened on it,
* and once for every filesystem mounted from it.
*/
new_driver_e = dmap[maj].dmap_driver;
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
int minor;
if (vmp->m_dev == NO_DEV) continue;
if ( ((vmp->m_dev >> MAJOR) & BYTE) != maj) continue;
minor = ((vmp->m_dev >> MINOR) & BYTE);
if ((r = dev_open(vmp->m_dev, FS_PROC_NR,
vmp->m_flags ? R_BIT : (R_BIT|W_BIT))) != OK) {
printf("VFS: mounted dev %d/%d re-open failed: %d.\n",
maj, minor, r);
}
/* Send new driver endpoint */
if (OK != req_newdriver(vmp->m_fs_e, vmp->m_dev, new_driver_e))
printf("VFSdev_up: error sending new driver endpoint."
" FS_e: %d req_nr: %d\n", vmp->m_fs_e, REQ_NEW_DRIVER);
}
/* Look for processes that are suspened in an OPEN call. Set SUSP_REOPEN
* to indicate that this process was suspended before the call to dev_up.
*/
for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
if(rfp->fp_pid == PID_FREE) continue;
if(rfp->fp_blocked_on != FP_BLOCKED_ON_DOPEN) continue;
printf("dev_up: found process in FP_BLOCKED_ON_DOPEN, fd %d\n",
rfp->fp_fd >> 8);
fd_nr = (rfp->fp_fd >> 8);
fp = rfp->fp_filp[fd_nr];
vp = fp->filp_vno;
if (!vp) panic(__FILE__, "restart_reopen: no vp", NO_NUM);
if ((vp->v_mode & I_TYPE) != I_CHAR_SPECIAL) continue;
if (((vp->v_sdev >> MAJOR) & BYTE) != maj) continue;
rfp->fp_flags |= SUSP_REOPEN;
}
needs_reopen= FALSE;
for (fp = filp; fp < &filp[NR_FILPS]; fp++) {
struct vnode *vp;
int minor;
if(fp->filp_count < 1 || !(vp = fp->filp_vno)) continue;
if(((vp->v_sdev >> MAJOR) & BYTE) != maj) continue;
if(!(vp->v_mode & (I_BLOCK_SPECIAL|I_CHAR_SPECIAL))) continue;
fp->filp_state = FS_NEEDS_REOPEN;
needs_reopen = TRUE;
}
if (needs_reopen)
restart_reopen(maj);
}
/*===========================================================================*
* restart_reopen *
*===========================================================================*/
PRIVATE void restart_reopen(maj)
int maj;
{
int n, r, minor, fd_nr;
endpoint_t driver_e;
struct vnode *vp;
struct filp *fp;
struct fproc *rfp;
for (fp = filp; fp < &filp[NR_FILPS]; fp++) {
if (fp->filp_count < 1 || !(vp = fp->filp_vno)) continue;
if (fp->filp_state != FS_NEEDS_REOPEN) continue;
if (((vp->v_sdev >> MAJOR) & BYTE) != maj) continue;
if ((vp->v_mode & I_TYPE) != I_CHAR_SPECIAL) continue;
minor = ((vp->v_sdev >> MINOR) & BYTE);
if (!(fp->filp_flags & O_REOPEN)) {
/* File descriptor is to be closed when driver restarts. */
n = invalidate(fp);
if (n != fp->filp_count) {
printf("VFS: warning: invalidate/count "
"discrepancy (%d, %d)\n", n, fp->filp_count);
}
fp->filp_count = 0;
continue;
}
r = dev_reopen(vp->v_sdev, fp-filp, vp->v_mode & (R_BIT|W_BIT));
if (r == OK) return;
/* Device could not be reopened. Invalidate all filps on that device.*/
n = invalidate(fp);
if (n != fp->filp_count) {
printf("VFS: warning: invalidate/count "
"discrepancy (%d, %d)\n", n, fp->filp_count);
}
fp->filp_count = 0;
printf("VFS: file on dev %d/%d re-open failed: %d; "
"invalidated %d fd's.\n", maj, minor, r, n);
}
/* Nothing more to re-open. Restart suspended processes */
driver_e= dmap[maj].dmap_driver;
for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
if(rfp->fp_pid == PID_FREE) continue;
if(rfp->fp_blocked_on == FP_BLOCKED_ON_OTHER &&
rfp->fp_task == driver_e && (rfp->fp_flags & SUSP_REOPEN)) {
rfp->fp_flags &= ~SUSP_REOPEN;
rfp->fp_blocked_on = FP_BLOCKED_ON_NONE;
reply(rfp->fp_endpoint, ERESTART);
}
}
/* Look for processes that are suspened in an OPEN call */
for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
if (rfp->fp_pid == PID_FREE) continue;
if (rfp->fp_blocked_on == FP_BLOCKED_ON_DOPEN ||
!(rfp->fp_flags & SUSP_REOPEN)) continue;
printf("restart_reopen: found process in FP_BLOCKED_ON_DOPEN, fd %d\n",
rfp->fp_fd >> 8);
fd_nr = (rfp->fp_fd >> 8);
fp = rfp->fp_filp[fd_nr];
if (!fp) {
/* Open failed, and automatic reopen was not requested */
rfp->fp_blocked_on = FP_BLOCKED_ON_NONE;
FD_CLR(fd_nr, &rfp->fp_filp_inuse);
reply(rfp->fp_endpoint, EIO);
continue;
}
vp = fp->filp_vno;
if (!vp) panic(__FILE__, "restart_reopen: no vp", NO_NUM);
if ((vp->v_mode & I_TYPE) != I_CHAR_SPECIAL) continue;
if (((vp->v_sdev >> MAJOR) & BYTE) != maj) continue;
rfp->fp_blocked_on = FP_BLOCKED_ON_NONE;
reply(rfp->fp_endpoint, fd_nr);
}
}
/*===========================================================================*
* reopen_reply *
*===========================================================================*/
PUBLIC void reopen_reply()
{
endpoint_t driver_e;
int filp_no, status, maj;
struct filp *fp;
struct vnode *vp;
struct dmap *dp;
driver_e = m_in.m_source;
filp_no = m_in.REP_ENDPT;
status = m_in.REP_STATUS;
if (filp_no < 0 || filp_no >= NR_FILPS) {
printf("reopen_reply: bad filp number %d from driver %d\n", filp_no,
driver_e);
return;
}
fp = &filp[filp_no];
if (fp->filp_count < 1) {
printf("reopen_reply: filp number %d not inuse (from driver %d)\n",
filp_no, driver_e);
return;
}
vp = fp->filp_vno;
if (!vp) {
printf("reopen_reply: no vnode for filp number %d (from driver %d)\n",
filp_no, driver_e);
return;
}
if (fp->filp_state != FS_NEEDS_REOPEN) {
printf("reopen_reply: bad state %d for filp number %d"
" (from driver %d)\n", fp->filp_state, filp_no, driver_e);
return;
}
if ((vp->v_mode & I_TYPE) != I_CHAR_SPECIAL) {
printf("reopen_reply: bad mode 0%o for filp number %d"
" (from driver %d)\n", vp->v_mode, filp_no, driver_e);
return;
}
maj = ((vp->v_sdev >> MAJOR) & BYTE);
dp = &dmap[maj];
if (dp->dmap_driver != driver_e) {
printf("reopen_reply: bad major %d for filp number %d "
"(from driver %d, current driver is %d)\n", maj, filp_no,
driver_e, dp->dmap_driver);
return;
}
if (status == OK) {
fp->filp_state= FS_NORMAL;
} else {
printf("reopen_reply: should handle error status\n");
return;
}
restart_reopen(maj);
}
#if 0
#define ASYN_NR 100
PRIVATE asynmsg_t msgtable[ASYN_NR];
PRIVATE int first_slot= 0, next_slot= 0;
PUBLIC int asynsend(dst, mp)
endpoint_t dst;
message *mp;
{
int r, src_ind, dst_ind;
unsigned flags;
/* Update first_slot */
for (; first_slot < next_slot; first_slot++)
{
flags= msgtable[first_slot].flags;
if ((flags & (AMF_VALID|AMF_DONE)) == (AMF_VALID|AMF_DONE))
{
if (msgtable[first_slot].result != OK)
{
printf(
"asynsend: found completed entry %d with error %d\n",
first_slot,
msgtable[first_slot].result);
}
continue;
}
if (flags != AMF_EMPTY)
break;
}
if (first_slot >= next_slot)
{
/* Reset first_slot and next_slot */
next_slot= first_slot= 0;
}
if (next_slot >= ASYN_NR)
{
/* Tell the kernel to stop processing */
r= senda(NULL, 0);
if (r != OK)
panic(__FILE__, "asynsend: senda failed", r);
dst_ind= 0;
for (src_ind= first_slot; src_ind<next_slot; src_ind++)
{
flags= msgtable[src_ind].flags;
if ((flags & (AMF_VALID|AMF_DONE)) ==
(AMF_VALID|AMF_DONE))
{
if (msgtable[src_ind].result != OK)
{
printf(
"asynsend: found completed entry %d with error %d\n",
src_ind,
msgtable[src_ind].result);
}
continue;
}
if (flags == AMF_EMPTY)
continue;
#if 0
printf("asynsend: copying entry %d to %d\n",
src_ind, dst_ind);
#endif
if (src_ind != dst_ind)
msgtable[dst_ind]= msgtable[src_ind];
dst_ind++;
}
first_slot= 0;
next_slot= dst_ind;
if (next_slot >= ASYN_NR)
panic(__FILE__, "asynsend: msgtable full", NO_NUM);
}
msgtable[next_slot].dst= dst;
msgtable[next_slot].msg= *mp;
msgtable[next_slot].flags= AMF_VALID; /* Has to be last. The kernel
* scans this table while we
* are sleeping.
*/
next_slot++;
/* Tell the kernel to rescan the table */
return senda(msgtable+first_slot, next_slot-first_slot);
}
#endif
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