/* 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 #include #include #include #include #include #include #include #include "file.h" #include "fproc.h" #include #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_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_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("OK on reopen from: %d", dp->dmap_driver); if (r == SUSPEND) r = OK; return(r); } /*===========================================================================* * dev_close * *===========================================================================*/ PUBLIC int dev_close( 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_style == STYLE_DEVA) { printf("dev_status: not doing dev_status for async driver %d\n", m->m_source); return; } do { int r; st.m_type = DEV_STATUS; r = sendrec(m->m_source, &st); if(r == OK && st.REP_STATUS == ERESTART) r = EDEADEPT; if (r != OK) { printf("DEV_STATUS failed to %d: %d\n", m->m_source, r); if (r == EDEADSRCDST || r == EDEADEPT) return; panic("couldn't sendrec for DEV_STATUS: %d", r); } switch(st.m_type) { case DEV_REVIVE: endpt = st.REP_ENDPT; if(endpt == VFS_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_reply2(st.m_source, 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("cpf_grant_magic of buffer failed"); 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("cpf_grant_direct of vector failed"); v = (iovec_t *) *buf; /* Grant access to i/o buffers. */ for(j = 0; j < bytes; j++) { if(j >= NR_IOREQS) panic("vec too big: %d", 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("grant to iovec buf failed"); 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("cpf_grant_magic failed (ioctl)"); break; case VFS_DEV_SELECT: *op = DEV_SELECT; break; default: panic("safe_io_conversion: unknown operation: %d", *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 = VFS_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( 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, safe; void *buf_used; endpoint_t ioproc; pos_lo= ex64lo(pos); pos_high= ex64hi(pos); /* Determine task dmap. */ dp = &dmap[(dev >> MAJOR) & BYTE]; /* 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.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, gids, NR_IOREQS, (endpoint_t*) &dev_mess.USER_ENDPT, &buf_used, &vec_grants, bytes, &pos_lo); if(buf != buf_used) panic("dev_io: safe_io_conversion changed buffer"); /* 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.USER_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("SUSPEND on vectored i/o"); /* fp is uninitialized at init time. */ if(!fp) panic("SUSPEND on NULL fp"); if ((flags & O_NONBLOCK) && !(dp->dmap_style == STYLE_DEVA)) { /* Not supposed to block. */ 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_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.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_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( 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.USER_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( 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( 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)) == NULL) 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->USER_ENDPT; for (;;) { r = sendrec(task_nr, mess_ptr); if(r == OK && mess_ptr->REP_STATUS == ERESTART) r = EDEADEPT; if (r != OK) { if (r == EDEADSRCDST || r == EDEADEPT) { 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("call_task: can't send/receive: %d", r); } /* Did the process we did the sendrec() for get a result? */ if (mess_ptr->REP_ENDPT != proc_e && VFS_PROC_NR != 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); } if (mess_ptr->m_type == TASK_REPLY || IS_DEV_RS(mess_ptr->m_type) || mess_ptr->m_type <= 0) { break; /* reply */ } else { nested_dev_call(mess_ptr); } } 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; r = asynsend(task_nr, mess_ptr); if (r != OK) panic("asyn_io: asynsend failed: %d", 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( 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 * *===========================================================================*/ 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( 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.USER_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 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 = (dev & ~(BYTE << MINOR)) | (dev_mess.REP_STATUS << MINOR); /* 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 */ vp = fp->fp_filp[m_in.fd]->filp_vno; put_vnode(vp); if ((vp = get_free_vnode()) == NULL) vp = fp->fp_filp[m_in.fd]->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[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, found; struct filp *fp; struct vmnt *vmp; struct fproc *rfp; struct vnode *vp; /* First deal with block devices. We need to consider both mounted file * systems and open block-special files. */ new_driver_e = dmap[maj].dmap_driver; /* Tell each affected mounted file system about the new endpoint. This code * is currently useless, as driver endpoints do not change across restarts. */ for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) { if (major(vmp->m_dev) != maj) continue; /* Send the new driver endpoint to the mounted file system. */ 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); } /* For each block-special file that was previously opened on the affected * device, we need to reopen it on the new driver. */ found = 0; for (fp = filp; fp < &filp[NR_FILPS]; fp++) { if(fp->filp_count < 1 || !(vp = fp->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. */ if ((r = dev_open(vp->v_sdev, VFS_PROC_NR, fp->filp_mode)) != OK) printf("VFS: mounted dev %d/%d re-open failed: %d.\n", maj, minor(vp->v_sdev), r); found = 1; } /* If any block-special file was open for this major at all, also inform the * root file system about the new endpoint of the 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), new_driver_e)) printf("VFSdev_up: error sending new driver endpoint." " FS_e: %d req_nr: %d\n", ROOT_FS_E, REQ_NEW_DRIVER); } /* The rest of the code deals with character-special files. To start with, * 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_block_fd); fd_nr = rfp->fp_block_fd; fp = rfp->fp_filp[fd_nr]; vp = fp->filp_vno; if (!vp) panic("restart_reopen: no vp"); 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++) { if(fp->filp_count < 1 || !(vp = fp->filp_vno)) continue; if(((vp->v_sdev >> MAJOR) & BYTE) != maj) continue; if(!S_ISCHR(vp->v_mode)) 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_block_fd); fd_nr = rfp->fp_block_fd; 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("restart_reopen: no vp"); 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); }