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minix/servers/vfs/device.c
Thomas Veerman cfcce207c1 VFS: prevent unmapping drivers that don't support reopening 
libchardriver does not support DEV_REOPEN and will return ERESTART
when you do try it. This made VFS unhappy and concluded erroneously
that the driver was EDEADEPT.
2013-02-21 10:29:08 +00:00

1255 lines
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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: open a character device
* dev_reopen: reopen a character device after a driver crash
* dev_close: close a character device
* bdev_open: open a block device
* bdev_close: close a block 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
* pm_setsid: perform VFS's side of setsid system call
* do_ioctl: perform the IOCTL system call
*/
#include "fs.h"
#include <string.h>
#include <fcntl.h>
#include <assert.h>
#include <sys/stat.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 "scratchpad.h"
#include "dmap.h"
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"
#include "param.h"
static void restart_reopen(int major);
static int safe_io_conversion(endpoint_t, cp_grant_id_t *, int *,
endpoint_t *, void **, size_t, u32_t *);
static int dummyproc;
/*===========================================================================*
* dev_open *
*===========================================================================*/
int dev_open(
dev_t dev, /* device to open */
endpoint_t proc_e, /* process to open for */
int flags /* mode bits and flags */
)
{
/* Open a character device. */
int major, r;
/* Determine the major device number so as to 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 = major(dev);
if (major < 0 || major >= NR_DEVICES) major = 0;
if (dmap[major].dmap_driver == NONE) return(ENXIO);
r = (*dmap[major].dmap_opcl)(DEV_OPEN, dev, proc_e, flags);
return(r);
}
/*===========================================================================*
* dev_reopen *
*===========================================================================*/
int dev_reopen(
dev_t dev, /* device to open */
int filp_no, /* filp to reopen for */
int flags /* mode bits and flags */
)
{
/* Reopen a character device after a failing device driver. */
int major, r;
struct dmap *dp;
/* Determine the major device number and 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 = major(dev);
if (major < 0 || 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 == SUSPEND) r = OK;
return(r);
}
/*===========================================================================*
* dev_close *
*===========================================================================*/
int dev_close(
dev_t dev, /* device to close */
int filp_no
)
{
/* Close a character device. */
int r, major;
/* See if driver is roughly valid. */
major = major(dev);
if (major < 0 || major >= NR_DEVICES) return(ENXIO);
if (dmap[major].dmap_driver == NONE) return(ENXIO);
r = (*dmap[major].dmap_opcl)(DEV_CLOSE, dev, filp_no, 0);
return(r);
}
/*===========================================================================*
* dev_open *
*===========================================================================*/
int bdev_open(dev_t dev, int access)
{
/* Open a block device. */
int major;
major = major(dev);
if (major < 0 || major >= NR_DEVICES) return(ENXIO);
if (dmap[major].dmap_driver == NONE) return(ENXIO);
return (*dmap[major].dmap_opcl)(BDEV_OPEN, dev, 0, access);
}
/*===========================================================================*
* bdev_close *
*===========================================================================*/
int bdev_close(dev_t dev)
{
/* Close a block device. */
int major;
major = major(dev);
if (major < 0 || major >= NR_DEVICES) return(ENXIO);
if (dmap[major].dmap_driver == NONE) return(ENXIO);
return (*dmap[major].dmap_opcl)(BDEV_CLOSE, dev, 0, 0);
}
/*===========================================================================*
* bdev_ioctl *
*===========================================================================*/
static int bdev_ioctl(dev_t dev, endpoint_t proc_e, int req, void *buf)
{
/* Perform an I/O control operation on a block device. */
struct dmap *dp;
u32_t dummy;
cp_grant_id_t gid;
message dev_mess;
int op, major_dev, minor_dev;
major_dev = major(dev);
minor_dev = minor(dev);
/* Determine task dmap. */
dp = &dmap[major_dev];
if (dp->dmap_driver == NONE) {
printf("VFS: dev_io: no driver for major %d\n", major_dev);
return(ENXIO);
}
/* Set up a grant if necessary. */
op = VFS_DEV_IOCTL;
(void) safe_io_conversion(dp->dmap_driver, &gid, &op, &proc_e, &buf, req,
&dummy);
/* Set up the message passed to the task. */
memset(&dev_mess, 0, sizeof(dev_mess));
dev_mess.m_type = BDEV_IOCTL;
dev_mess.BDEV_MINOR = minor_dev;
dev_mess.BDEV_REQUEST = req;
dev_mess.BDEV_GRANT = gid;
dev_mess.BDEV_ID = 0;
/* Call the task. */
(*dp->dmap_io)(dp->dmap_driver, &dev_mess);
/* Clean up. */
if (GRANT_VALID(gid)) cpf_revoke(gid);
if (dp->dmap_driver == NONE) {
printf("VFS: block driver gone!?\n");
return(EIO);
}
/* Return the result. */
return(dev_mess.BDEV_STATUS);
}
/*===========================================================================*
* find_suspended_ep *
*===========================================================================*/
endpoint_t find_suspended_ep(endpoint_t driver, cp_grant_id_t g)
{
/* A process is suspended on a driver for which VFS 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 *
*===========================================================================*/
void dev_status(endpoint_t drv_e)
{
/* A device sent us a notification it has something for us. Retrieve it. */
message st;
int major, get_more = 1;
endpoint_t endpt;
for (major = 0; major < NR_DEVICES; major++)
if (dmap_driver_match(drv_e, major))
break; /* 'major' is the device that sent the message */
if (major >= NR_DEVICES) /* Device endpoint not found; nothing to do */
return;
if (dev_style_asyn(dmap[major].dmap_style)) {
printf("VFS: not doing dev_status for async driver %d\n", drv_e);
return;
}
/* Continuously send DEV_STATUS messages until the device has nothing to
* say to us anymore. */
do {
int r;
st.m_type = DEV_STATUS;
r = drv_sendrec(drv_e, &st);
if (r == OK && st.REP_STATUS == ERESTART) r = EDEADEPT;
if (r != OK) {
printf("VFS: DEV_STATUS failed to %d: %d\n", drv_e, r);
if (r == EDEADSRCDST || r == EDEADEPT) return;
panic("VFS: couldn't sendrec for DEV_STATUS: %d", r);
}
switch(st.m_type) {
case DEV_REVIVE:
/* We've got results for a read/write/ioctl call to a
* synchronous character driver */
endpt = st.REP_ENDPT;
if (endpt == VFS_PROC_NR) {
endpt = find_suspended_ep(drv_e, st.REP_IO_GRANT);
if (endpt == NONE) {
printf("VFS: proc with grant %d from %d not found\n",
st.REP_IO_GRANT, st.m_source);
continue;
}
}
revive(endpt, st.REP_STATUS);
break;
case DEV_IO_READY:
/* Reply to a select request: driver is ready for I/O */
select_reply2(st.m_source, st.DEV_MINOR, st.DEV_SEL_OPS);
break;
default:
printf("VFS: unrecognized reply %d to DEV_STATUS\n",st.m_type);
/* Fall through. */
case DEV_NO_STATUS:
get_more = 0;
break;
}
} while(get_more);
}
/*===========================================================================*
* safe_io_conversion *
*===========================================================================*/
static int safe_io_conversion(driver, gid, op, io_ept, buf, bytes, pos_lo)
endpoint_t driver;
cp_grant_id_t *gid;
int *op;
endpoint_t *io_ept;
void **buf;
size_t bytes;
u32_t *pos_lo;
{
/* Convert operation to the 'safe' variant (i.e., grant based) if applicable.
* If no copying of data is involved, there is also no need to convert. */
int access = 0;
size_t size;
*gid = GRANT_INVALID; /* Grant to buffer */
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("VFS: cpf_grant_magic of READ/WRITE buffer failed");
break;
case VFS_DEV_IOCTL:
*pos_lo = *io_ept; /* Old endpoint in POSITION field. */
*op = DEV_IOCTL_S;
/* For IOCTLs, the bytes parameter encodes requested access method
* and buffer size */
if(_MINIX_IOCTL_IOR(bytes)) access |= CPF_WRITE;
if(_MINIX_IOCTL_IOW(bytes)) access |= CPF_READ;
if(_MINIX_IOCTL_BIG(bytes))
size = _MINIX_IOCTL_SIZE_BIG(bytes);
else
size = _MINIX_IOCTL_SIZE(bytes);
/* Grant access to the buffer 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("VFS: cpf_grant_magic IOCTL buffer failed");
break;
case VFS_DEV_SELECT:
*op = DEV_SELECT;
break;
default:
panic("VFS: unknown operation %d for safe I/O conversion", *op);
}
/* If we have converted to a safe operation, I/O endpoint becomes VFS if it
* wasn't already.
*/
if(GRANT_VALID(*gid)) {
*io_ept = VFS_PROC_NR;
return(1);
}
/* Not converted to a safe operation (because there is no copying involved in
* this operation).
*/
return(0);
}
static int cancel_nblock(struct dmap * dp,
int minor,
int call,
endpoint_t ioproc,
cp_grant_id_t gid)
{
message dev_mess;
dev_mess.m_type = CANCEL;
dev_mess.USER_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 == READ)
dev_mess.COUNT = R_BIT;
else if (call == WRITE)
dev_mess.COUNT = W_BIT;
dev_mess.DEVICE = minor;
(*dp->dmap_io)(dp->dmap_driver, &dev_mess);
return dev_mess.REP_STATUS;
}
/*===========================================================================*
* dev_io *
*===========================================================================*/
int dev_io(
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 */
size_t bytes, /* how many bytes to transfer */
int flags, /* special flags, like O_NONBLOCK */
int suspend_reopen /* Just suspend the process */
)
{
/* Read from or write to 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;
int safe, minor_dev, major_dev;
void *buf_used;
endpoint_t ioproc;
int ret, is_asyn;
pos_lo = ex64lo(pos);
pos_high = ex64hi(pos);
major_dev = major(dev);
minor_dev = minor(dev);
/* Determine task dmap. */
dp = &dmap[major_dev];
/* See if driver is roughly valid. */
if (dp->dmap_driver == NONE) return(ENXIO);
if (suspend_reopen) {
/* Suspend user. */
fp->fp_grant = GRANT_INVALID;
fp->fp_ioproc = NONE;
wait_for(dp->dmap_driver);
fp->fp_flags |= FP_SUSP_REOPEN;
return(SUSPEND);
}
if(isokendpt(dp->dmap_driver, &dummyproc) != OK) {
printf("VFS: dev_io: old driver for major %x (%d)\n", major_dev,
dp->dmap_driver);
return(ENXIO);
}
/* By default, these are right. */
dev_mess.USER_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,
(endpoint_t *) &dev_mess.USER_ENDPT, &buf_used,
bytes, &pos_lo);
is_asyn = dev_style_asyn(dp->dmap_style);
/* If the safe conversion was done, set the IO_GRANT 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 = minor_dev;
dev_mess.POSITION = pos_lo;
dev_mess.COUNT = bytes;
dev_mess.HIGHPOS = pos_high;
dev_mess.FLAGS = 0;
if (flags & O_NONBLOCK)
dev_mess.FLAGS |= FLG_OP_NONBLOCK;
/* This will be used if the i/o is suspended. */
ioproc = dev_mess.USER_ENDPT;
/* Call the task. */
(*dp->dmap_io)(dp->dmap_driver, &dev_mess);
if(dp->dmap_driver == NONE) {
/* Driver has vanished. */
printf("VFS: driver gone?!\n");
if(safe) cpf_revoke(gid);
return(EIO);
}
ret = dev_mess.REP_STATUS;
/* Task has completed. See if call completed. */
if (ret == SUSPEND) {
if ((flags & O_NONBLOCK) && !is_asyn) {
/* Not supposed to block. */
ret = cancel_nblock(dp, minor_dev, job_call_nr, ioproc, gid);
if (ret == EINTR)
ret = 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) && !is_asyn) {
/* Not supposed to block, send cancel message */
cancel_nblock(dp, minor_dev, job_call_nr, ioproc, gid);
/*
* FIXME 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) cpf_revoke(gid);
return ret;
}
/*===========================================================================*
* gen_opcl *
*===========================================================================*/
int gen_opcl(
int op, /* operation, (B)DEV_OPEN or (B)DEV_CLOSE */
dev_t dev, /* device to open or close */
endpoint_t proc_e, /* process to open/close for */
int flags /* mode bits and flags */
)
{
/* Called from the dmap struct on opens & closes of special files.*/
int r, minor_dev, major_dev, is_bdev;
struct dmap *dp;
message dev_mess;
/* Determine task dmap. */
major_dev = major(dev);
minor_dev = minor(dev);
assert(major_dev >= 0 && major_dev < NR_DEVICES);
dp = &dmap[major_dev];
assert(dp->dmap_driver != NONE);
is_bdev = IS_BDEV_RQ(op);
if (is_bdev) {
memset(&dev_mess, 0, sizeof(dev_mess));
dev_mess.m_type = op;
dev_mess.BDEV_MINOR = minor_dev;
dev_mess.BDEV_ACCESS = flags;
dev_mess.BDEV_ID = 0;
} else {
dev_mess.m_type = op;
dev_mess.DEVICE = minor_dev;
dev_mess.USER_ENDPT = proc_e;
dev_mess.COUNT = flags;
}
/* Call the task. */
r = (*dp->dmap_io)(dp->dmap_driver, &dev_mess);
if (r != OK) return(r);
if (op == DEV_OPEN && dp->dmap_style == STYLE_DEVA) {
fp->fp_task = dp->dmap_driver;
worker_wait();
}
if (is_bdev)
return(dev_mess.BDEV_STATUS);
else
return(dev_mess.REP_STATUS);
}
/*===========================================================================*
* tty_opcl *
*===========================================================================*/
int tty_opcl(
int op, /* operation, DEV_OPEN or DEV_CLOSE */
dev_t dev, /* device to open or close */
endpoint_t 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;
assert(!IS_BDEV_RQ(op));
/* 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_flags & 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 *
*===========================================================================*/
int ctty_opcl(
int op, /* operation, DEV_OPEN or DEV_CLOSE */
dev_t UNUSED(dev), /* device to open or close */
endpoint_t UNUSED(proc_e), /* process to open/close for */
int UNUSED(flags) /* mode bits and flags */
)
{
/* This procedure is called from the dmap struct on opening or closing
* /dev/tty, the magic device that translates to the controlling tty.
*/
if (IS_BDEV_RQ(op))
panic("ctty_opcl() called for block device request?");
return(fp->fp_tty == 0 ? ENXIO : OK);
}
/*===========================================================================*
* pm_setsid *
*===========================================================================*/
void pm_setsid(endpoint_t proc_e)
{
/* Perform the VFS 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_flags |= FP_SESLDR;
rfp->fp_tty = 0;
}
/*===========================================================================*
* do_ioctl *
*===========================================================================*/
int do_ioctl()
{
/* Perform the ioctl(ls_fd, request, argx) system call */
int r = OK, suspend_reopen, ioctlrequest;
struct filp *f;
register struct vnode *vp;
dev_t dev;
void *argx;
scratch(fp).file.fd_nr = job_m_in.ls_fd;
ioctlrequest = job_m_in.REQUEST;
argx = job_m_in.ADDRESS;
if ((f = get_filp(scratch(fp).file.fd_nr, VNODE_READ)) == NULL)
return(err_code);
vp = f->filp_vno; /* get vnode pointer */
if (!S_ISCHR(vp->v_mode) && !S_ISBLK(vp->v_mode)) {
r = ENOTTY;
}
if (r == OK) {
suspend_reopen = (f->filp_state & FS_NEEDS_REOPEN);
dev = (dev_t) vp->v_sdev;
if (S_ISBLK(vp->v_mode))
r = bdev_ioctl(dev, who_e, ioctlrequest, argx);
else
r = dev_io(VFS_DEV_IOCTL, dev, who_e, argx, cvu64(0),
ioctlrequest, f->filp_flags, suspend_reopen);
}
unlock_filp(f);
return(r);
}
/*===========================================================================*
* gen_io *
*===========================================================================*/
int gen_io(driver_e, mess_ptr)
endpoint_t driver_e; /* which endpoint 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, status = OK, proc_e = NONE, is_bdev, retry_count;
message mess_retry;
is_bdev = IS_BDEV_RQ(mess_ptr->m_type);
mess_retry = *mess_ptr;
retry_count = 0;
if (!is_bdev) proc_e = mess_ptr->USER_ENDPT;
do {
r = drv_sendrec(driver_e, mess_ptr);
if (r == OK) {
if (is_bdev)
status = mess_ptr->BDEV_STATUS;
else
status = mess_ptr->REP_STATUS;
if (status == ERESTART) {
r = EDEADEPT;
*mess_ptr = mess_retry;
retry_count++;
}
}
} while (status == ERESTART && retry_count < 5);
/* If we failed to restart the request, return EIO */
if (status == ERESTART && retry_count >= 5) {
r = OK;
mess_ptr->m_type = EIO;
}
if (r != OK) {
if (r == EDEADSRCDST || r == EDEADEPT) {
printf("VFS: dead driver %d\n", driver_e);
dmap_unmap_by_endpt(driver_e);
return(r);
} else if (r == ELOCKED) {
printf("VFS: ELOCKED talking to %d\n", driver_e);
return(r);
}
panic("call_task: can't send/receive: %d", r);
}
/* Did the process we did the sendrec() for get a result? */
if (!is_bdev && mess_ptr->REP_ENDPT != proc_e && mess_ptr->m_type != EIO) {
printf("VFS: 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);
} else if (!IS_DRV_REPLY(mess_ptr->m_type))
return(EIO);
return(OK);
}
/*===========================================================================*
* asyn_io *
*===========================================================================*/
int asyn_io(endpoint_t drv_e, message *mess_ptr)
{
/* 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;
assert(!IS_BDEV_RQ(mess_ptr->m_type));
self->w_drv_sendrec = mess_ptr; /* Remember where result should be stored */
self->w_task = drv_e;
r = asynsend3(drv_e, mess_ptr, AMF_NOREPLY);
if (r != OK) panic("VFS: asynsend in asyn_io failed: %d", r);
/* Fake a SUSPEND */
mess_ptr->REP_STATUS = SUSPEND;
return(OK);
}
/*===========================================================================*
* ctty_io *
*===========================================================================*/
int ctty_io(
endpoint_t UNUSED(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[major(fp->fp_tty)];
mess_ptr->DEVICE = minor(fp->fp_tty);
if (dp->dmap_driver == NONE) {
printf("FS: ctty_io: no driver for dev\n");
return(EIO);
}
if (isokendpt(dp->dmap_driver, &dummyproc) != OK) {
printf("VFS: ctty_io: old driver %d\n", dp->dmap_driver);
return(EIO);
}
(*dp->dmap_io)(dp->dmap_driver, mess_ptr);
}
return(OK);
}
/*===========================================================================*
* no_dev *
*===========================================================================*/
int no_dev(
int UNUSED(op), /* operation, DEV_OPEN or DEV_CLOSE */
dev_t UNUSED(dev), /* device to open or close */
int UNUSED(proc), /* process to open/close for */
int UNUSED(flags) /* mode bits and flags */
)
{
/* Called when opening a nonexistent device. */
return(ENODEV);
}
/*===========================================================================*
* no_dev_io *
*===========================================================================*/
int no_dev_io(endpoint_t UNUSED(proc), message *UNUSED(m))
{
/* Called when doing i/o on a nonexistent device. */
printf("VFS: I/O on unmapped device number\n");
return(EIO);
}
/*===========================================================================*
* clone_opcl *
*===========================================================================*/
int clone_opcl(
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_dev, major_dev;
message dev_mess;
assert(!IS_BDEV_RQ(op));
/* Determine task dmap. */
minor_dev = minor(dev);
major_dev = major(dev);
assert(major_dev >= 0 && major_dev < NR_DEVICES);
dp = &dmap[major_dev];
assert(dp->dmap_driver != NONE);
dev_mess.m_type = op;
dev_mess.DEVICE = minor_dev;
dev_mess.USER_ENDPT = proc_e;
dev_mess.COUNT = flags;
if(isokendpt(dp->dmap_driver, &dummyproc) != OK) {
printf("VFS clone_opcl: bad driver endpoint for major %d (%d)\n",
major_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_style_asyn(dp->dmap_style)) {
/* Wait for reply when driver is asynchronous */
fp->fp_task = dp->dmap_driver;
worker_wait();
}
if (op == DEV_OPEN && dev_mess.REP_STATUS >= 0) {
if (dev_mess.REP_STATUS != minor_dev) {
struct vnode *vp;
struct node_details res;
/* A new minor device number has been returned.
* Request PFS to create a temporary device file to hold it.
*/
/* Device number of the new device. */
dev = makedev(major(dev), minor(dev_mess.REP_STATUS));
/* Issue request */
r = req_newnode(PFS_PROC_NR, 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 */
if ((vp = get_free_vnode()) == NULL)
return(err_code);
lock_vnode(vp, VNODE_OPCL);
assert(FD_ISSET(scratch(fp).file.fd_nr, &fp->fp_filp_inuse));
unlock_vnode(fp->fp_filp[scratch(fp).file.fd_nr]->filp_vno);
put_vnode(fp->fp_filp[scratch(fp).file.fd_nr]->filp_vno);
vp->v_fs_e = res.fs_e;
vp->v_vmnt = NULL;
vp->v_dev = NO_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[scratch(fp).file.fd_nr]->filp_vno = vp;
}
dev_mess.REP_STATUS = OK;
}
return(dev_mess.REP_STATUS);
}
/*===========================================================================*
* bdev_up *
*===========================================================================*/
void bdev_up(int maj)
{
/* A new block device driver has been mapped in. This may affect both mounted
* file systems and open block-special files.
*/
int r, found, bits;
struct filp *rfilp;
struct vmnt *vmp;
struct vnode *vp;
char *label;
if (maj < 0 || maj >= NR_DEVICES) panic("VFS: out-of-bound major");
label = dmap[maj].dmap_label;
found = 0;
/* For each block-special file that was previously opened on the affected
* device, we need to reopen it on the new driver.
*/
for (rfilp = filp; rfilp < &filp[NR_FILPS]; rfilp++) {
if (rfilp->filp_count < 1 || !(vp = rfilp->filp_vno)) continue;
if (major(vp->v_sdev) != maj) continue;
if (!S_ISBLK(vp->v_mode)) continue;
/* Reopen the device on the driver, once per filp. */
bits = mode_map[rfilp->filp_mode & O_ACCMODE];
if ((r = bdev_open(vp->v_sdev, bits)) != OK) {
printf("VFS: mounted dev %d/%d re-open failed: %d.\n",
maj, minor(vp->v_sdev), r);
dmap[maj].dmap_recovering = 0;
return; /* Give up entirely */
}
found = 1;
}
/* Tell each affected mounted file system about the new endpoint.
*/
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
if (major(vmp->m_dev) != maj) continue;
/* Send the driver label to the mounted file system. */
if (OK != req_newdriver(vmp->m_fs_e, vmp->m_dev, label))
printf("VFS dev_up: error sending new driver label to %d\n",
vmp->m_fs_e);
}
/* If any block-special file was open for this major at all, also inform the
* root file system about the new driver. We do this even if the
* block-special file is linked to another mounted file system, merely
* because it is more work to check for that case.
*/
if (found) {
if (OK != req_newdriver(ROOT_FS_E, makedev(maj, 0), label))
printf("VFSdev_up: error sending new driver label to %d\n",
ROOT_FS_E);
}
}
/*===========================================================================*
* cdev_up *
*===========================================================================*/
void cdev_up(int maj)
{
/* A new character device driver has been mapped in.
*/
int needs_reopen, fd_nr;
struct filp *rfilp;
struct fproc *rfp;
struct vnode *vp;
/* Look for processes that are suspended in an OPEN call. Set FP_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;
fd_nr = scratch(rfp).file.fd_nr;
printf("VFS: dev_up: found process in FP_BLOCKED_ON_DOPEN, fd %d\n",
fd_nr);
rfilp = rfp->fp_filp[fd_nr];
vp = rfilp->filp_vno;
if (!vp) panic("VFS: cdev_up: no vp");
if (!S_ISCHR(vp->v_mode)) continue;
if (major(vp->v_sdev) != maj) continue;
rfp->fp_flags |= FP_SUSP_REOPEN;
}
needs_reopen= FALSE;
for (rfilp = filp; rfilp < &filp[NR_FILPS]; rfilp++) {
if (rfilp->filp_count < 1 || !(vp = rfilp->filp_vno)) continue;
if (major(vp->v_sdev) != maj) continue;
if (!S_ISCHR(vp->v_mode)) continue;
rfilp->filp_state |= FS_NEEDS_REOPEN;
needs_reopen = TRUE;
}
if (needs_reopen)
restart_reopen(maj);
}
/*===========================================================================*
* open_reply *
*===========================================================================*/
void open_reply(void)
{
struct fproc *rfp;
struct worker_thread *wp;
endpoint_t proc_e;
int slot;
proc_e = job_m_in.REP_ENDPT;
if (isokendpt(proc_e, &slot) != OK) return;
rfp = &fproc[slot];
wp = worker_get(rfp->fp_wtid);
if (wp == NULL || wp->w_task != who_e) {
printf("VFS: no worker thread waiting for a reply from %d\n", who_e);
return;
}
*wp->w_drv_sendrec = job_m_in;
wp->w_drv_sendrec = NULL;
wp->w_task = NONE;
worker_signal(wp); /* Continue open */
}
/*===========================================================================*
* dev_reply *
*===========================================================================*/
void dev_reply(struct dmap *dp)
{
struct worker_thread *wp;
assert(dp != NULL);
assert(dp->dmap_servicing != NONE);
wp = worker_get(dp->dmap_servicing);
if (wp == NULL || wp->w_task != who_e) {
printf("VFS: no worker thread waiting for a reply from %d\n",
who_e);
return;
}
assert(wp->w_drv_sendrec != NULL);
*wp->w_drv_sendrec = m_in;
wp->w_drv_sendrec = NULL;
worker_signal(wp);
}
/*===========================================================================*
* restart_reopen *
*===========================================================================*/
static void restart_reopen(maj)
int maj;
{
int n, r, minor_dev, major_dev, fd_nr;
endpoint_t driver_e;
struct vnode *vp;
struct filp *rfilp;
struct fproc *rfp;
if (maj < 0 || maj >= NR_DEVICES) panic("VFS: out-of-bound major");
for (rfilp = filp; rfilp < &filp[NR_FILPS]; rfilp++) {
if (rfilp->filp_count < 1 || !(vp = rfilp->filp_vno)) continue;
if (!(rfilp->filp_state & FS_NEEDS_REOPEN)) continue;
if (!S_ISCHR(vp->v_mode)) continue;
major_dev = major(vp->v_sdev);
minor_dev = minor(vp->v_sdev);
if (major_dev != maj) continue;
if (rfilp->filp_flags & O_REOPEN) {
/* Try to reopen a file upon driver restart */
r = dev_reopen(vp->v_sdev, rfilp-filp,
vp->v_mode & (R_BIT|W_BIT));
if (r == OK)
return;
printf("VFS: file on dev %d/%d re-open failed: %d\n",
major_dev, minor_dev, r);
}
/* File descriptor is to be closed when driver restarts. */
n = invalidate_filp(rfilp);
if (n != rfilp->filp_count) {
printf("VFS: warning: invalidate/count "
"discrepancy (%d, %d)\n", n, rfilp->filp_count);
}
rfilp->filp_count = 0;
/* We have to clean up this filp and vnode, but can't do that yet as
* it's locked by a worker thread. Start a new job to garbage collect
* invalidated filps associated with this device driver.
*/
sys_worker_start(do_filp_gc);
}
/* 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 & FP_SUSP_REOPEN)) {
rfp->fp_flags &= ~FP_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 & FP_SUSP_REOPEN)) continue;
fd_nr = scratch(rfp).file.fd_nr;
printf("VFS: restart_reopen: process in FP_BLOCKED_ON_DOPEN fd=%d\n",
fd_nr);
rfilp = rfp->fp_filp[fd_nr];
if (!rfilp) {
/* 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 = rfilp->filp_vno;
if (!vp) panic("VFS: restart_reopen: no vp");
if (!S_ISCHR(vp->v_mode)) continue;
if (major(vp->v_sdev) != maj) continue;
rfp->fp_blocked_on = FP_BLOCKED_ON_NONE;
reply(rfp->fp_endpoint, fd_nr);
}
}
/*===========================================================================*
* reopen_reply *
*===========================================================================*/
void reopen_reply()
{
endpoint_t driver_e;
int filp_no, status, maj;
struct filp *rfilp;
struct vnode *vp;
struct dmap *dp;
driver_e = job_m_in.m_source;
filp_no = job_m_in.REP_ENDPT;
status = job_m_in.REP_STATUS;
if (filp_no < 0 || filp_no >= NR_FILPS) {
printf("VFS: reopen_reply: bad filp number %d from driver %d\n",
filp_no, driver_e);
return;
}
rfilp = &filp[filp_no];
if (rfilp->filp_count < 1) {
printf("VFS: reopen_reply: filp number %d not inuse (from driver %d)\n",
filp_no, driver_e);
return;
}
vp = rfilp->filp_vno;
if (!vp) {
printf("VFS: reopen_reply: no vnode for filp number %d (from driver "
"%d)\n", filp_no, driver_e);
return;
}
if (!(rfilp->filp_state & FS_NEEDS_REOPEN)) {
printf("VFS: reopen_reply: bad state %d for filp number %d"
" (from driver %d)\n", rfilp->filp_state, filp_no, driver_e);
return;
}
if (!S_ISCHR(vp->v_mode)) {
printf("VFS: reopen_reply: bad mode 0%o for filp number %d"
" (from driver %d)\n", vp->v_mode, filp_no, driver_e);
return;
}
maj = major(vp->v_sdev);
dp = &dmap[maj];
if (dp->dmap_driver != driver_e) {
printf("VFS: 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) {
rfilp->filp_state &= ~FS_NEEDS_REOPEN;
} else {
printf("VFS: reopen_reply: should handle error status\n");
return;
}
restart_reopen(maj);
}
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