/*===========================================================================*
* pipe_open *
*===========================================================================*/
static int pipe_open(struct vnode *vp, mode_t bits, int oflags)
{
/* This function is called from common_open. It checks if
* there is at least one reader/writer pair for the pipe, if not
* it suspends the caller, otherwise it revives all other blocked
* processes hanging on the pipe.
*/
if ((bits & (R_BIT|W_BIT)) == (R_BIT|W_BIT)) return(ENXIO);
/* Find the reader/writer at the other end of the pipe */
if (find_filp(vp, bits & W_BIT ? R_BIT : W_BIT) == NULL) {
/* Not found */
if (oflags & O_NONBLOCK) {
if (bits & W_BIT) return(ENXIO);
} else {
/* Let's wait for the other side to show up */
suspend(FP_BLOCKED_ON_POPEN);
return(SUSPEND);
}
} else if (susp_count > 0) { /* revive blocked processes */
release(vp, OPEN, susp_count);
release(vp, CREAT, susp_count);
}
return(OK);
}
/*===========================================================================*
* pipe_open *
*===========================================================================*/
PRIVATE int pipe_open(register struct vnode *vp, register mode_t bits,
register int oflags)
{
/* This function is called from common_open. It checks if
* there is at least one reader/writer pair for the pipe, if not
* it suspends the caller, otherwise it revives all other blocked
* processes hanging on the pipe.
*/
vp->v_pipe = I_PIPE;
if((bits & (R_BIT|W_BIT)) == (R_BIT|W_BIT)) return(ENXIO);
if (find_filp(vp, bits & W_BIT ? R_BIT : W_BIT) == NULL) {
if (oflags & O_NONBLOCK) {
if (bits & W_BIT) return(ENXIO);
} else {
suspend(FP_BLOCKED_ON_POPEN); /* suspend caller */
return(SUSPEND);
}
} else if (susp_count > 0) { /* revive blocked processes */
release(vp, OPEN, susp_count);
release(vp, CREAT, susp_count);
}
return(OK);
}
/*===========================================================================*
* common_open *
*===========================================================================*/
int common_open(char path[PATH_MAX], int oflags, mode_t omode)
{
/* Common code from do_creat and do_open. */
int b, r, exist = TRUE, major_dev;
dev_t dev;
mode_t bits;
struct filp *filp, *filp2;
struct vnode *vp;
struct vmnt *vmp;
struct dmap *dp;
struct lookup resolve;
/* Remap the bottom two bits of oflags. */
bits = (mode_t) mode_map[oflags & O_ACCMODE];
if (!bits) return(EINVAL);
/* See if file descriptor and filp slots are available. */
if ((r = get_fd(0, bits, &(scratch(fp).file.fd_nr), &filp)) != OK) return(r);
lookup_init(&resolve, path, PATH_NOFLAGS, &vmp, &vp);
/* If O_CREATE is set, try to make the file. */
if (oflags & O_CREAT) {
omode = I_REGULAR | (omode & ALLPERMS & fp->fp_umask);
vp = new_node(&resolve, oflags, omode);
r = err_code;
if (r == OK) exist = FALSE; /* We just created the file */
else if (r != EEXIST) { /* other error */
if (vp) unlock_vnode(vp);
unlock_filp(filp);
return(r);
}
else exist = !(oflags & O_EXCL);/* file exists, if the O_EXCL
flag is set this is an error */
} else {
/* Scan path name */
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_OPCL;
if ((vp = eat_path(&resolve, fp)) == NULL) {
unlock_filp(filp);
return(err_code);
}
if (vmp != NULL) unlock_vmnt(vmp);
}
/* Claim the file descriptor and filp slot and fill them in. */
fp->fp_filp[scratch(fp).file.fd_nr] = filp;
FD_SET(scratch(fp).file.fd_nr, &fp->fp_filp_inuse);
filp->filp_count = 1;
filp->filp_vno = vp;
filp->filp_flags = oflags;
/* Only do the normal open code if we didn't just create the file. */
if (exist) {
/* Check protections. */
if ((r = forbidden(fp, vp, bits)) == OK) {
/* Opening reg. files, directories, and special files differ */
switch (vp->v_mode & S_IFMT) {
case S_IFREG:
/* Truncate regular file if O_TRUNC. */
if (oflags & O_TRUNC) {
if ((r = forbidden(fp, vp, W_BIT)) != OK)
break;
truncate_vnode(vp, 0);
}
break;
case S_IFDIR:
/* Directories may be read but not written. */
r = (bits & W_BIT ? EISDIR : OK);
break;
case S_IFCHR:
/* Invoke the driver for special processing. */
dev = (dev_t) vp->v_sdev;
/* TTY needs to know about the O_NOCTTY flag. */
r = dev_open(dev, who_e, bits | (oflags & O_NOCTTY));
if (r == SUSPEND) suspend(FP_BLOCKED_ON_DOPEN);
else vp = filp->filp_vno; /* Might be updated by
* dev_open/clone_opcl */
break;
case S_IFBLK:
lock_bsf();
/* Invoke the driver for special processing. */
dev = (dev_t) vp->v_sdev;
r = bdev_open(dev, bits);
if (r != OK) {
unlock_bsf();
break;
}
major_dev = major(vp->v_sdev);
dp = &dmap[major_dev];
if (dp->dmap_driver == NONE) {
printf("VFS: block driver disappeared!\n");
unlock_bsf();
r = ENXIO;
break;
}
/* Check whether the device is mounted or not. If so,
* then that FS is responsible for this device.
* Otherwise we default to ROOT_FS.
*/
vp->v_bfs_e = ROOT_FS_E; /* By default */
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp)
if (vmp->m_dev == vp->v_sdev &&
!(vmp->m_flags & VMNT_FORCEROOTBSF)) {
vp->v_bfs_e = vmp->m_fs_e;
}
/* Send the driver label to the file system that will
* handle the block I/O requests (even when its label
* and endpoint are known already), but only when it is
* the root file system. Other file systems will
* already have it anyway.
*/
if (vp->v_bfs_e != ROOT_FS_E) {
unlock_bsf();
break;
}
if (req_newdriver(vp->v_bfs_e, vp->v_sdev,
dp->dmap_label) != OK) {
printf("VFS: error sending driver label\n");
bdev_close(dev);
r = ENXIO;
}
unlock_bsf();
break;
case S_IFIFO:
/* Create a mapped inode on PFS which handles reads
and writes to this named pipe. */
tll_upgrade(&vp->v_lock);
r = map_vnode(vp, PFS_PROC_NR);
if (r == OK) {
if (vp->v_ref_count == 1) {
vp->v_pipe_rd_pos = 0;
vp->v_pipe_wr_pos = 0;
if (vp->v_size != 0)
r = truncate_vnode(vp, 0);
}
oflags |= O_APPEND; /* force append mode */
filp->filp_flags = oflags;
}
if (r == OK) {
r = pipe_open(vp, bits, oflags);
}
if (r != ENXIO) {
/* See if someone else is doing a rd or wt on
* the FIFO. If so, use its filp entry so the
* file position will be automatically shared.
*/
b = (bits & R_BIT ? R_BIT : W_BIT);
filp->filp_count = 0; /* don't find self */
if ((filp2 = find_filp(vp, b)) != NULL) {
/* Co-reader or writer found. Use it.*/
fp->fp_filp[scratch(fp).file.fd_nr] = filp2;
filp2->filp_count++;
filp2->filp_vno = vp;
filp2->filp_flags = oflags;
/* v_count was incremented after the vnode
* has been found. i_count was incremented
* incorrectly in FS, not knowing that we
* were going to use an existing filp
* entry. Correct this error.
*/
unlock_vnode(vp);
put_vnode(vp);
} else {
/* Nobody else found. Restore filp. */
filp->filp_count = 1;
}
}
break;
}
}
}
unlock_filp(filp);
/* If error, release inode. */
if (r != OK) {
if (r != SUSPEND) {
fp->fp_filp[scratch(fp).file.fd_nr] = NULL;
FD_CLR(scratch(fp).file.fd_nr, &fp->fp_filp_inuse);
filp->filp_count = 0;
filp->filp_vno = NULL;
put_vnode(vp);
}
} else {
r = scratch(fp).file.fd_nr;
}
return(r);
}
/*===========================================================================*
* common_open *
*===========================================================================*/
PUBLIC int common_open(register int oflags, mode_t omode)
{
/* Common code from do_creat and do_open. */
int b, r, exist = TRUE;
dev_t dev;
mode_t bits;
struct filp *fil_ptr, *filp2;
struct vnode *vp;
struct vmnt *vmp;
struct dmap *dp;
/* Remap the bottom two bits of oflags. */
bits = (mode_t) mode_map[oflags & O_ACCMODE];
if (!bits) return(EINVAL);
/* See if file descriptor and filp slots are available. */
if ((r = get_fd(0, bits, &m_in.fd, &fil_ptr)) != OK) return(r);
/* If O_CREATE is set, try to make the file. */
if (oflags & O_CREAT) {
omode = I_REGULAR | (omode & ALL_MODES & fp->fp_umask);
vp = new_node(oflags, omode);
r = err_code;
if (r == OK) exist = FALSE; /* We just created the file */
else if (r != EEXIST) return(r); /* other error */
else exist = !(oflags & O_EXCL); /* file exists, if the O_EXCL
flag is set this is an error */
} else {
/* Scan path name */
if ((vp = eat_path(PATH_NOFLAGS, fp)) == NULL) return(err_code);
}
/* Claim the file descriptor and filp slot and fill them in. */
fp->fp_filp[m_in.fd] = fil_ptr;
FD_SET(m_in.fd, &fp->fp_filp_inuse);
fil_ptr->filp_count = 1;
fil_ptr->filp_vno = vp;
fil_ptr->filp_flags = oflags;
/* Only do the normal open code if we didn't just create the file. */
if(exist) {
/* Check protections. */
if ((r = forbidden(vp, bits)) == OK) {
/* Opening reg. files, directories, and special files differ */
switch (vp->v_mode & I_TYPE) {
case I_REGULAR:
/* Truncate regular file if O_TRUNC. */
if (oflags & O_TRUNC) {
if ((r = forbidden(vp, W_BIT)) != OK)
break;
truncate_vnode(vp, 0);
}
break;
case I_DIRECTORY:
/* Directories may be read but not written. */
r = (bits & W_BIT ? EISDIR : OK);
break;
case I_CHAR_SPECIAL:
/* Invoke the driver for special processing. */
dev = (dev_t) vp->v_sdev;
/* TTY needs to know about the O_NOCTTY flag. */
r = dev_open(dev, who_e, bits | (oflags & O_NOCTTY));
if (r == SUSPEND) suspend(FP_BLOCKED_ON_DOPEN);
break;
case I_BLOCK_SPECIAL:
/* Invoke the driver for special processing. */
dev = (dev_t) vp->v_sdev;
r = bdev_open(dev, bits);
if (r != OK) break;
/* Check whether the device is mounted or not. If so,
then that FS is responsible for this device. Else
we default to ROOT_FS. */
vp->v_bfs_e = ROOT_FS_E; /* By default */
for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp)
if (vmp->m_dev == vp->v_sdev)
vp->v_bfs_e = vmp->m_fs_e;
/* Get the driver endpoint of the block spec device */
dp = &dmap[major(vp->v_sdev)];
/* Send the driver endpoint to the file system (even
* when known already).
*/
if ((r = req_newdriver(vp->v_bfs_e, vp->v_sdev,
dp->dmap_driver)) != OK) {
printf("VFS: error sending driver endpoint\n");
bdev_close(dev);
r = ENXIO;
}
break;
case I_NAMED_PIPE:
/* Create a mapped inode on PFS which handles reads
and writes to this named pipe. */
r = map_vnode(vp);
if (r == OK) {
vp->v_pipe = I_PIPE;
if (vp->v_ref_count == 1) {
vp->v_pipe_rd_pos = 0;
vp->v_pipe_wr_pos = 0;
if (vp->v_size != 0)
r = truncate_vnode(vp, 0);
}
oflags |= O_APPEND; /* force append mode */
fil_ptr->filp_flags = oflags;
}
if (r == OK) {
r = pipe_open(vp, bits, oflags);
}
if (r != ENXIO) {
/* See if someone else is doing a rd or wt on
* the FIFO. If so, use its filp entry so the
* file position will be automatically shared.
*/
b = (bits & R_BIT ? R_BIT : W_BIT);
fil_ptr->filp_count = 0; /* don't find self */
if ((filp2 = find_filp(vp, b)) != NULL) {
/* Co-reader or writer found. Use it.*/
fp->fp_filp[m_in.fd] = filp2;
filp2->filp_count++;
filp2->filp_vno = vp;
filp2->filp_flags = oflags;
/* v_count was incremented after the
* vnode has been found. i_count was
* incremented incorrectly in FS, not
* knowing that we were going to use an
* existing filp entry. Correct this
* error.
*/
put_vnode(vp);
} else {
/* Nobody else found. Restore filp. */
fil_ptr->filp_count = 1;
}
}
break;
}
}
}
/* If error, release inode. */
if (r != OK) {
if (r == SUSPEND) return(r); /* Oops, just suspended */
fp->fp_filp[m_in.fd] = NULL;
FD_CLR(m_in.fd, &fp->fp_filp_inuse);
fil_ptr->filp_count= 0;
put_vnode(vp);
fil_ptr->filp_vno = NULL;
return(r);
}
return(m_in.fd);
}
/*===========================================================================*
* common_open *
*===========================================================================*/
PRIVATE int common_open(register int oflags, mode_t omode)
{
/* Common code from do_creat and do_open. */
struct inode *rip, *ldirp;
int r, b, exist = TRUE;
dev_t dev;
mode_t bits;
off_t pos;
struct filp *fil_ptr, *filp2;
/* Remap the bottom two bits of oflags. */
bits = (mode_t) mode_map[oflags & O_ACCMODE];
/* See if file descriptor and filp slots are available. */
if ( (r = get_fd(0, bits, &m_in.fd, &fil_ptr)) != OK) return(r);
/* If O_CREATE is set, try to make the file. */
if (oflags & O_CREAT) {
/* Create a new inode by calling new_node(). */
omode = I_REGULAR | (omode & ALL_MODES & fp->fp_umask);
rip = new_node(&ldirp, user_path, omode, NO_ZONE, oflags&O_EXCL, NULL);
r = err_code;
put_inode(ldirp);
if (r == OK) exist = FALSE; /* we just created the file */
else if (r != EEXIST) return(r); /* other error */
else exist = !(oflags & O_EXCL); /* file exists, if the O_EXCL
flag is set this is an error */
} else {
/* Scan path name. */
if ( (rip = eat_path(user_path)) == NIL_INODE) return(err_code);
}
/* Claim the file descriptor and filp slot and fill them in. */
fp->fp_filp[m_in.fd] = fil_ptr;
FD_SET(m_in.fd, &fp->fp_filp_inuse);
fil_ptr->filp_count = 1;
fil_ptr->filp_ino = rip;
fil_ptr->filp_flags = oflags;
/* Only do the normal open code if we didn't just create the file. */
if (exist) {
/* Check protections. */
if ((r = forbidden(rip, bits)) == OK) {
/* Opening reg. files directories and special files differ. */
switch (rip->i_mode & I_TYPE) {
case I_REGULAR:
/* Truncate regular file if O_TRUNC. */
if (oflags & O_TRUNC) {
if ((r = forbidden(rip, W_BIT)) !=OK) break;
truncate_inode(rip, 0);
wipe_inode(rip);
/* Send the inode from the inode cache to the
* block cache, so it gets written on the next
* cache flush.
*/
rw_inode(rip, WRITING);
}
break;
case I_DIRECTORY:
/* Directories may be read but not written. */
r = (bits & W_BIT ? EISDIR : OK);
break;
case I_CHAR_SPECIAL:
case I_BLOCK_SPECIAL:
/* Invoke the driver for special processing. */
dev = (dev_t) rip->i_zone[0];
r = dev_open(dev, who_e, bits | (oflags & ~O_ACCMODE));
break;
case I_NAMED_PIPE:
oflags |= O_APPEND; /* force append mode */
fil_ptr->filp_flags = oflags;
r = pipe_open(rip, bits, oflags);
if (r != ENXIO) {
/* See if someone else is doing a rd or wt on
* the FIFO. If so, use its filp entry so the
* file position will be automatically shared.
*/
b = (bits & R_BIT ? R_BIT : W_BIT);
fil_ptr->filp_count = 0; /* don't find self */
if ((filp2 = find_filp(rip, b)) != NIL_FILP) {
/* Co-reader or writer found. Use it.*/
fp->fp_filp[m_in.fd] = filp2;
filp2->filp_count++;
filp2->filp_ino = rip;
filp2->filp_flags = oflags;
/* i_count was incremented incorrectly
* by eatpath above, not knowing that
* we were going to use an existing
* filp entry. Correct this error.
*/
rip->i_count--;
} else {
/* Nobody else found. Restore filp. */
fil_ptr->filp_count = 1;
if (b == R_BIT)
pos = rip->i_zone[V2_NR_DZONES+0];
else
pos = rip->i_zone[V2_NR_DZONES+1];
fil_ptr->filp_pos = pos;
}
}
break;
}
}
}
/* If error, release inode. */
if (r != OK) {
if (r == SUSPEND) return(r); /* Oops, just suspended */
fp->fp_filp[m_in.fd] = NIL_FILP;
FD_CLR(m_in.fd, &fp->fp_filp_inuse);
fil_ptr->filp_count= 0;
put_inode(rip);
return(r);
}
return(m_in.fd);
}
