/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All rights reserved. */
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* FIFOFS file system vnode operations. This file system
* type supports STREAMS-based pipes and FIFOs.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/cred.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/kmem.h>
#include <sys/uio.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/vfs_opreg.h>
#include <sys/pathname.h>
#include <sys/signal.h>
#include <sys/user.h>
#include <sys/strsubr.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/strredir.h>
#include <sys/fs/fifonode.h>
#include <sys/fs/namenode.h>
#include <sys/stropts.h>
#include <sys/proc.h>
#include <sys/unistd.h>
#include <sys/debug.h>
#include <fs/fs_subr.h>
#include <sys/filio.h>
#include <sys/termio.h>
#include <sys/ddi.h>
#include <sys/vtrace.h>
#include <sys/policy.h>
#include <sys/tsol/label.h>
/*
* Define the routines/data structures used in this file.
*/
static int fifo_read(vnode_t *, uio_t *, int, cred_t *, caller_context_t *);
static int fifo_write(vnode_t *, uio_t *, int, cred_t *, caller_context_t *);
static int fifo_getattr(vnode_t *, vattr_t *, int, cred_t *,
caller_context_t *);
static int fifo_setattr(vnode_t *, vattr_t *, int, cred_t *,
caller_context_t *);
static int fifo_realvp(vnode_t *, vnode_t **, caller_context_t *);
static int fifo_access(vnode_t *, int, int, cred_t *, caller_context_t *);
static int fifo_create(struct vnode *, char *, vattr_t *, enum vcexcl,
int, struct vnode **, struct cred *, int, caller_context_t *,
vsecattr_t *);
static int fifo_fid(vnode_t *, fid_t *, caller_context_t *);
static int fifo_fsync(vnode_t *, int, cred_t *, caller_context_t *);
static int fifo_seek(vnode_t *, offset_t, offset_t *, caller_context_t *);
static int fifo_ioctl(vnode_t *, int, intptr_t, int, cred_t *, int *,
caller_context_t *);
static int fifo_fastioctl(vnode_t *, int, intptr_t, int, cred_t *, int *);
static int fifo_strioctl(vnode_t *, int, intptr_t, int, cred_t *, int *);
static int fifo_poll(vnode_t *, short, int, short *, pollhead_t **,
caller_context_t *);
static int fifo_pathconf(vnode_t *, int, ulong_t *, cred_t *,
caller_context_t *);
static void fifo_inactive(vnode_t *, cred_t *, caller_context_t *);
static int fifo_rwlock(vnode_t *, int, caller_context_t *);
static void fifo_rwunlock(vnode_t *, int, caller_context_t *);
static int fifo_setsecattr(struct vnode *, vsecattr_t *, int, struct cred *,
caller_context_t *);
static int fifo_getsecattr(struct vnode *, vsecattr_t *, int, struct cred *,
caller_context_t *);
/* functions local to this file */
static boolean_t fifo_stayfast_enter(fifonode_t *);
static void fifo_stayfast_exit(fifonode_t *);
/*
* Define the data structures external to this file.
*/
extern dev_t fifodev;
extern struct qinit fifo_stwdata;
extern struct qinit fifo_strdata;
extern kmutex_t ftable_lock;
struct streamtab fifoinfo = { &fifo_strdata, &fifo_stwdata, NULL, NULL };
struct vnodeops *fifo_vnodeops;
const fs_operation_def_t fifo_vnodeops_template[] = {
VOPNAME_OPEN, { .vop_open = fifo_open },
VOPNAME_CLOSE, { .vop_close = fifo_close },
VOPNAME_READ, { .vop_read = fifo_read },
VOPNAME_WRITE, { .vop_write = fifo_write },
VOPNAME_IOCTL, { .vop_ioctl = fifo_ioctl },
VOPNAME_GETATTR, { .vop_getattr = fifo_getattr },
VOPNAME_SETATTR, { .vop_setattr = fifo_setattr },
VOPNAME_ACCESS, { .vop_access = fifo_access },
VOPNAME_CREATE, { .vop_create = fifo_create },
VOPNAME_FSYNC, { .vop_fsync = fifo_fsync },
VOPNAME_INACTIVE, { .vop_inactive = fifo_inactive },
VOPNAME_FID, { .vop_fid = fifo_fid },
VOPNAME_RWLOCK, { .vop_rwlock = fifo_rwlock },
VOPNAME_RWUNLOCK, { .vop_rwunlock = fifo_rwunlock },
VOPNAME_SEEK, { .vop_seek = fifo_seek },
VOPNAME_REALVP, { .vop_realvp = fifo_realvp },
VOPNAME_POLL, { .vop_poll = fifo_poll },
VOPNAME_PATHCONF, { .vop_pathconf = fifo_pathconf },
VOPNAME_DISPOSE, { .error = fs_error },
VOPNAME_SETSECATTR, { .vop_setsecattr = fifo_setsecattr },
VOPNAME_GETSECATTR, { .vop_getsecattr = fifo_getsecattr },
NULL, NULL
};
/*
* Return the fifoinfo structure.
*/
struct streamtab *
fifo_getinfo()
{
return (&fifoinfo);
}
/*
* Trusted Extensions enforces a restrictive policy for
* writing via cross-zone named pipes. A privileged global
* zone process may expose a named pipe by loopback mounting
* it from a lower-level zone to a higher-level zone. The
* kernel-enforced mount policy for lofs mounts ensures
* that such mounts are read-only in the higher-level
* zone. But this is not sufficient to prevent writing
* down via fifos. This function prevents writing down
* by comparing the zone of the process which is requesting
* write access with the zone owning the named pipe rendezvous.
* For write access the zone of the named pipe must equal the
* zone of the writing process. Writing up is possible since
* the named pipe can be opened for read by a process in a
* higher level zone.
*
* An exception is made for the global zone to support trusted
* processes which enforce their own data flow policies.
*/
static boolean_t
tsol_fifo_access(vnode_t *vp, int flag, cred_t *crp)
{
fifonode_t *fnp = VTOF(vp);
if (is_system_labeled() &&
(flag & FWRITE) &&
(!(fnp->fn_flag & ISPIPE))) {
zone_t *proc_zone;
proc_zone = crgetzone(crp);
if (proc_zone != global_zone) {
char vpath[MAXPATHLEN];
zone_t *fifo_zone;
/*
* Get the pathname and use it to find
* the zone of the fifo.
*/
if (vnodetopath(rootdir, vp, vpath, sizeof (vpath),
kcred) == 0) {
fifo_zone = zone_find_by_path(vpath);
zone_rele(fifo_zone);
if (fifo_zone != global_zone &&
fifo_zone != proc_zone) {
return (B_FALSE);
}
} else {
return (B_FALSE);
}
}
}
return (B_TRUE);
}
/*
* Open and stream a FIFO.
* If this is the first open of the file (FIFO is not streaming),
* initialize the fifonode and attach a stream to the vnode.
*
* Each end of a fifo must be synchronized with the other end.
* If not, the mated end may complete an open, I/O, close sequence
* before the end waiting in open ever wakes up.
* Note: namefs pipes come through this routine too.
*/
int
fifo_open(vnode_t **vpp, int flag, cred_t *crp, caller_context_t *ct)
{
vnode_t *vp = *vpp;
fifonode_t *fnp = VTOF(vp);
fifolock_t *fn_lock = fnp->fn_lock;
int error;
ASSERT(vp->v_type == VFIFO);
ASSERT(vn_matchops(vp, fifo_vnodeops));
if (!tsol_fifo_access(vp, flag, crp))
return (EACCES);
mutex_enter(&fn_lock->flk_lock);
/*
* If we are the first reader, wake up any writers that
* may be waiting around. wait for all of them to
* wake up before proceeding (i.e. fn_wsynccnt == 0)
*/
if (flag & FREAD) {
fnp->fn_rcnt++; /* record reader present */
if (! (fnp->fn_flag & ISPIPE))
fnp->fn_rsynccnt++; /* record reader in open */
}
/*
* If we are the first writer, wake up any readers that
* may be waiting around. wait for all of them to
* wake up before proceeding (i.e. fn_rsynccnt == 0)
*/
if (flag & FWRITE) {
fnp->fn_wcnt++; /* record writer present */
if (! (fnp->fn_flag & ISPIPE))
fnp->fn_wsynccnt++; /* record writer in open */
}
/*
* fifo_stropen will take care of twisting the queues on the first
* open. The 1 being passed in means twist the queues on the first
* open.
*/
error = fifo_stropen(vpp, flag, crp, 1, 1);
/*
* fifo_stropen() could have replaced vpp
* since fifo's are the only thing we need to sync up,
* everything else just returns;
* Note: don't need to hold lock since ISPIPE can't change
* and both old and new vp need to be pipes
*/
ASSERT(MUTEX_HELD(&VTOF(*vpp)->fn_lock->flk_lock));
if (fnp->fn_flag & ISPIPE) {
ASSERT(VTOF(*vpp)->fn_flag & ISPIPE);
ASSERT(VTOF(*vpp)->fn_rsynccnt == 0);
ASSERT(VTOF(*vpp)->fn_rsynccnt == 0);
/*
* XXX note: should probably hold locks, but
* These values should not be changing
*/
ASSERT(fnp->fn_rsynccnt == 0);
ASSERT(fnp->fn_wsynccnt == 0);
mutex_exit(&VTOF(*vpp)->fn_lock->flk_lock);
return (error);
}
/*
* vp can't change for FIFOS
*/
ASSERT(vp == *vpp);
/*
* If we are opening for read (or writer)
* indicate that the reader (or writer) is done with open
* if there is a writer (or reader) waiting for us, wake them up
* and indicate that at least 1 read (or write) open has occurred
* this is need in the event the read (or write) side closes
* before the writer (or reader) has a chance to wake up
* i.e. it sees that a reader (or writer) was once there
*/
if (flag & FREAD) {
fnp->fn_rsynccnt--; /* reader done with open */
if (fnp->fn_flag & FIFOSYNC) {
/*
* This indicates that a read open has occurred
* Only need to set if writer is actually asleep
* Flag will be consumed by writer.
*/
fnp->fn_flag |= FIFOROCR;
cv_broadcast(&fnp->fn_wait_cv);
}
}
if (flag & FWRITE) {
fnp->fn_wsynccnt--; /* writer done with open */
if (fnp->fn_flag & FIFOSYNC) {
/*
* This indicates that a write open has occurred
* Only need to set if reader is actually asleep
* Flag will be consumed by reader.
*/
fnp->fn_flag |= FIFOWOCR;
cv_broadcast(&fnp->fn_wait_cv);
}
}
fnp->fn_flag &= ~FIFOSYNC;
/*
* errors don't wait around.. just return
* Note: XXX other end will wake up and continue despite error.
* There is no defined semantic on the correct course of option
* so we do what we've done in the past
*/
if (error != 0) {
mutex_exit(&fnp->fn_lock->flk_lock);
goto done;
}
ASSERT(fnp->fn_rsynccnt <= fnp->fn_rcnt);
ASSERT(fnp->fn_wsynccnt <= fnp->fn_wcnt);
/*
* FIFOWOCR (or FIFOROCR) indicates that the writer (or reader)
* has woken us up and is done with open (this way, if the other
* end has made it to close, we don't block forever in open)
* fn_wnct == fn_wsynccnt (or fn_rcnt == fn_rsynccnt) indicates
* that no writer (or reader) has yet made it through open
* This has the side benefit of that the first
* reader (or writer) will wait until the other end finishes open
*/
if (flag & FREAD) {
while ((fnp->fn_flag & FIFOWOCR) == 0 &&
fnp->fn_wcnt == fnp->fn_wsynccnt) {
if (flag & (FNDELAY|FNONBLOCK)) {
mutex_exit(&fnp->fn_lock->flk_lock);
goto done;
}
fnp->fn_insync++;
fnp->fn_flag |= FIFOSYNC;
if (!cv_wait_sig_swap(&fnp->fn_wait_cv,
&fnp->fn_lock->flk_lock)) {
/*
* Last reader to wakeup clear writer
* Clear both writer and reader open
* occurred flag incase other end is O_RDWR
*/
if (--fnp->fn_insync == 0 &&
fnp->fn_flag & FIFOWOCR) {
fnp->fn_flag &= ~(FIFOWOCR|FIFOROCR);
}
mutex_exit(&fnp->fn_lock->flk_lock);
(void) fifo_close(*vpp, flag, 1, 0, crp, ct);
error = EINTR;
goto done;
}
/*
* Last reader to wakeup clear writer open occurred flag
* Clear both writer and reader open occurred flag
* incase other end is O_RDWR
*/
if (--fnp->fn_insync == 0 &&
fnp->fn_flag & FIFOWOCR) {
fnp->fn_flag &= ~(FIFOWOCR|FIFOROCR);
break;
}
}
} else if (flag & FWRITE) {
while ((fnp->fn_flag & FIFOROCR) == 0 &&
fnp->fn_rcnt == fnp->fn_rsynccnt) {
if ((flag & (FNDELAY|FNONBLOCK)) && fnp->fn_rcnt == 0) {
mutex_exit(&fnp->fn_lock->flk_lock);
(void) fifo_close(*vpp, flag, 1, 0, crp, ct);
error = ENXIO;
goto done;
}
fnp->fn_flag |= FIFOSYNC;
fnp->fn_insync++;
if (!cv_wait_sig_swap(&fnp->fn_wait_cv,
&fnp->fn_lock->flk_lock)) {
/*
* Last writer to wakeup clear
* Clear both writer and reader open
* occurred flag in case other end is O_RDWR
*/
if (--fnp->fn_insync == 0 &&
(fnp->fn_flag & FIFOROCR) != 0) {
fnp->fn_flag &= ~(FIFOWOCR|FIFOROCR);
}
mutex_exit(&fnp->fn_lock->flk_lock);
(void) fifo_close(*vpp, flag, 1, 0, crp, ct);
error = EINTR;
goto done;
}
/*
* Last writer to wakeup clear reader open occurred flag
* Clear both writer and reader open
* occurred flag in case other end is O_RDWR
*/
if (--fnp->fn_insync == 0 &&
(fnp->fn_flag & FIFOROCR) != 0) {
fnp->fn_flag &= ~(FIFOWOCR|FIFOROCR);
break;
}
}
}
mutex_exit(&fn_lock->flk_lock);
done:
return (error);
}
/*
* Close down a stream.
* Call cleanlocks() and strclean() on every close.
* For last close send hangup message and force
* the other end of a named pipe to be unmounted.
* Mount guarantees that the mounted end will only call fifo_close()
* with a count of 1 when the unmount occurs.
* This routine will close down one end of a pipe or FIFO
* and free the stream head via strclose()
*/
/*ARGSUSED*/
int
fifo_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *crp,
caller_context_t *ct)
{
fifonode_t *fnp = VTOF(vp);
fifonode_t *fn_dest = fnp->fn_dest;
int error = 0;
fifolock_t *fn_lock = fnp->fn_lock;
queue_t *sd_wrq;
vnode_t *fn_dest_vp;
int senthang = 0;
ASSERT(vp->v_stream != NULL);
/*
* clean locks and clear events.
*/
(void) cleanlocks(vp, ttoproc(curthread)->p_pid, 0);
cleanshares(vp, ttoproc(curthread)->p_pid);
strclean(vp);
/*
* If a file still has the pipe/FIFO open, return.
*/
if (count > 1)
return (0);
sd_wrq = strvp2wq(vp);
mutex_enter(&fn_lock->flk_lock);
/*
* wait for pending opens to finish up
* note: this also has the side effect of single threading closes
*/
while (fn_lock->flk_ocsync)
cv_wait(&fn_lock->flk_wait_cv, &fn_lock->flk_lock);
fn_lock->flk_ocsync = 1;
if (flag & FREAD) {
fnp->fn_rcnt--;
}
/*
* If we are last writer wake up sleeping readers
* (They'll figure out that there are no more writers
* and do the right thing)
* send hangup down stream so that stream head will do the
* right thing.
*/
if (flag & FWRITE) {
if (--fnp->fn_wcnt == 0 && fn_dest->fn_rcnt > 0) {
if ((fn_dest->fn_flag & (FIFOFAST | FIFOWANTR)) ==
(FIFOFAST | FIFOWANTR)) {
/*
* While we're at it, clear FIFOWANTW too
* Wake up any sleeping readers or
* writers.
*/
fn_dest->fn_flag &= ~(FIFOWANTR | FIFOWANTW);
cv_broadcast(&fn_dest->fn_wait_cv);
}
/*
* This is needed incase the other side
* was opened non-blocking. It is the
* only way we can tell that wcnt is 0 because
* of close instead of never having a writer
*/
if (!(fnp->fn_flag & ISPIPE))
fnp->fn_flag |= FIFOCLOSE;
/*
* Note: sending hangup effectively shuts down
* both reader and writer at other end.
*/
(void) putnextctl_wait(sd_wrq, M_HANGUP);
senthang = 1;
}
}
/*
* For FIFOs we need to indicate to stream head that last reader
* has gone away so that an error is generated
* Pipes just need to wake up the other end so that it can
* notice this end has gone away.
*/
if (fnp->fn_rcnt == 0 && fn_dest->fn_wcnt > 0) {
if ((fn_dest->fn_flag & (FIFOFAST | FIFOWANTW)) ==
(FIFOFAST | FIFOWANTW)) {
/*
* wake up any sleeping writers
*/
fn_dest->fn_flag &= ~FIFOWANTW;
cv_broadcast(&fn_dest->fn_wait_cv);
}
}
/*
* if there are still processes with this FIFO open
* clear open/close sync flag
* and just return;
*/
if (--fnp->fn_open > 0) {
ASSERT((fnp->fn_rcnt + fnp->fn_wcnt) != 0);
fn_lock->flk_ocsync = 0;
cv_broadcast(&fn_lock->flk_wait_cv);
mutex_exit(&fn_lock->flk_lock);
return (0);
}
/*
* Need to send HANGUP if other side is still open
* (fnp->fn_rcnt or fnp->fn_wcnt may not be zero (some thread
* on this end of the pipe may still be in fifo_open())
*
* Note: we can get here with fn_rcnt and fn_wcnt != 0 if some
* thread is blocked somewhere in the fifo_open() path prior to
* fifo_stropen() incrementing fn_open. This can occur for
* normal FIFOs as well as named pipes. fn_rcnt and
* fn_wcnt only indicate attempts to open. fn_open indicates
* successful opens. Partially opened FIFOs should proceed
* normally; i.e. they will appear to be new opens. Partially
* opened pipes will probably fail.
*/
if (fn_dest->fn_open && senthang == 0)
(void) putnextctl_wait(sd_wrq, M_HANGUP);
/*
* If this a pipe and this is the first end to close,
* then we have a bit of cleanup work to do.
* Mark both ends of pipe as closed.
* Wake up anybody blocked at the other end and for named pipes,
* Close down this end of the stream
* Allow other opens/closes to continue
* force an unmount of other end.
* Otherwise if this is last close,
* flush messages,
* close down the stream
* allow other opens/closes to continue
*/
fnp->fn_flag &= ~FIFOISOPEN;
if ((fnp->fn_flag & ISPIPE) && !(fnp->fn_flag & FIFOCLOSE)) {
fnp->fn_flag |= FIFOCLOSE;
fn_dest->fn_flag |= FIFOCLOSE;
if (fnp->fn_flag & FIFOFAST)
fifo_fastflush(fnp);
if (vp->v_stream != NULL) {
mutex_exit(&fn_lock->flk_lock);
(void) strclose(vp, flag, crp);
mutex_enter(&fn_lock->flk_lock);
}
cv_broadcast(&fn_dest->fn_wait_cv);
/*
* allow opens and closes to proceed
* Since this end is now closed down, any attempt
* to do anything with this end will fail
*/
fn_lock->flk_ocsync = 0;
cv_broadcast(&fn_lock->flk_wait_cv);
fn_dest_vp = FTOV(fn_dest);
/*
* if other end of pipe has been opened and it's
* a named pipe, unmount it
*/
if (fn_dest_vp->v_stream &&
(fn_dest_vp->v_stream->sd_flag & STRMOUNT)) {
/*
* We must hold the destination vnode because
* nm_unmountall() causes close to be called
* for the other end of named pipe. This
* could free the vnode before we are ready.
*/
VN_HOLD(fn_dest_vp);
mutex_exit(&fn_lock->flk_lock);
error = nm_unmountall(fn_dest_vp, crp);
ASSERT(error == 0);
VN_RELE(fn_dest_vp);
} else {
ASSERT(vp->v_count >= 1);
mutex_exit(&fn_lock->flk_lock);
}
} else {
if (fnp->fn_flag & FIFOFAST)
fifo_fastflush(fnp);
#if DEBUG
fn_dest_vp = FTOV(fn_dest);
if (fn_dest_vp->v_stream)
ASSERT((fn_dest_vp->v_stream->sd_flag & STRMOUNT) == 0);
#endif
if (vp->v_stream != NULL) {
mutex_exit(&fn_lock->flk_lock);
(void) strclose(vp, flag, crp);
mutex_enter(&fn_lock->flk_lock);
}
fn_lock->flk_ocsync = 0;
cv_broadcast(&fn_lock->flk_wait_cv);
cv_broadcast(&fn_dest->fn_wait_cv);
mutex_exit(&fn_lock->flk_lock);
}
return (error);
}
/*
* Read from a pipe or FIFO.
* return 0 if....
* (1) user read request is 0 or no stream
* (2) broken pipe with no data
* (3) write-only FIFO with no data
* (4) no data and FNDELAY flag is set.
* Otherwise return
* EAGAIN if FNONBLOCK is set and no data to read
* EINTR if signal received while waiting for data
*
* While there is no data to read....
* - if the NDELAY/NONBLOCK flag is set, return 0/EAGAIN.
* - wait for a write.
*
*/
/*ARGSUSED*/
static int
fifo_read(struct vnode *vp, struct uio *uiop, int ioflag, struct cred *crp,
caller_context_t *ct)
{
fifonode_t *fnp = VTOF(vp);
fifonode_t *fn_dest;
fifolock_t *fn_lock = fnp->fn_lock;
int error = 0;
mblk_t *bp;
ASSERT(vp->v_stream != NULL);
if (uiop->uio_resid == 0)
return (0);
mutex_enter(&fn_lock->flk_lock);
TRACE_2(TR_FAC_FIFO, TR_FIFOREAD_IN, "fifo_read in:%p fnp %p", vp, fnp);
if (! (fnp->fn_flag & FIFOFAST))
goto stream_mode;
fn_dest = fnp->fn_dest;
/*
* Check for data on our input queue
*/
while (fnp->fn_count == 0) {
/*
* No data on first attempt and no writer, then EOF
*/
if (fn_dest->fn_wcnt == 0 || fn_dest->fn_rcnt == 0) {
mutex_exit(&fn_lock->flk_lock);
return (0);
}
/*
* no data found.. if non-blocking, return EAGAIN
* otherwise 0.
*/
if (uiop->uio_fmode & (FNDELAY|FNONBLOCK)) {
mutex_exit(&fn_lock->flk_lock);
if (uiop->uio_fmode & FNONBLOCK)
return (EAGAIN);
return (0);
}
/*
* Note: FIFOs can get here with FIFOCLOSE set if
* write side is in the middle of opeining after
* it once closed. Pipes better not have FIFOCLOSE set
*/
ASSERT((fnp->fn_flag & (ISPIPE|FIFOCLOSE)) !=
(ISPIPE|FIFOCLOSE));
/*
* wait for data
*/
fnp->fn_flag |= FIFOWANTR;
TRACE_1(TR_FAC_FIFO, TR_FIFOREAD_WAIT, "fiforead wait: %p", vp);
if (!cv_wait_sig_swap(&fnp->fn_wait_cv,
&fn_lock->flk_lock)) {
error = EINTR;
goto done;
}
TRACE_1(TR_FAC_FIFO, TR_FIFOREAD_WAKE,
"fiforead awake: %p", vp);
/*
* check to make sure we are still in fast mode
*/
if (!(fnp->fn_flag & FIFOFAST))
goto stream_mode;
}
ASSERT(fnp->fn_mp != NULL);
/* For pipes copy should not bypass cache */
uiop->uio_extflg |= UIO_COPY_CACHED;
do {
int bpsize = MBLKL(fnp->fn_mp);
int uiosize = MIN(bpsize, uiop->uio_resid);
error = uiomove(fnp->fn_mp->b_rptr, uiosize, UIO_READ, uiop);
if (error != 0)
break;
fnp->fn_count -= uiosize;
if (bpsize <= uiosize) {
bp = fnp->fn_mp;
fnp->fn_mp = fnp->fn_mp->b_cont;
freeb(bp);
if (uiop->uio_resid == 0)
break;
while (fnp->fn_mp == NULL && fn_dest->fn_wwaitcnt > 0) {
ASSERT(fnp->fn_count == 0);
if (uiop->uio_fmode & (FNDELAY|FNONBLOCK))
goto trywake;
/*
* We've consumed all available data but there
* are threads waiting to write more, let them
* proceed before bailing.
*/
fnp->fn_flag |= FIFOWANTR;
fifo_wakewriter(fn_dest, fn_lock);
if (!cv_wait_sig(&fnp->fn_wait_cv,
&fn_lock->flk_lock))
goto trywake;
if (!(fnp->fn_flag & FIFOFAST))
goto stream_mode;
}
} else {
fnp->fn_mp->b_rptr += uiosize;
ASSERT(uiop->uio_resid == 0);
}
} while (uiop->uio_resid != 0 && fnp->fn_mp != NULL);
trywake:
ASSERT(msgdsize(fnp->fn_mp) == fnp->fn_count);
/*
* wake up any blocked writers, processes
* sleeping on POLLWRNORM, or processes waiting for SIGPOLL
* Note: checking for fn_count < Fifohiwat emulates
* STREAMS functionality when low water mark is 0
*/
if (fn_dest->fn_flag & (FIFOWANTW | FIFOHIWATW) &&
fnp->fn_count < Fifohiwat) {
fifo_wakewriter(fn_dest, fn_lock);
}
goto done;
/*
* FIFO is in streams mode.. let the stream head handle it
*/
stream_mode:
mutex_exit(&fn_lock->flk_lock);
TRACE_1(TR_FAC_FIFO,
TR_FIFOREAD_STREAM, "fifo_read stream_mode:%p", vp);
error = strread(vp, uiop, crp);
mutex_enter(&fn_lock->flk_lock);
done:
/*
* vnode update access time
*/
if (error == 0) {
time_t now = gethrestime_sec();
if (fnp->fn_flag & ISPIPE)
fnp->fn_dest->fn_atime = now;
fnp->fn_atime = now;
}
TRACE_2(TR_FAC_FIFO, TR_FIFOREAD_OUT,
"fifo_read out:%p error %d", vp, error);
mutex_exit(&fn_lock->flk_lock);
return (error);
}
/*
* send SIGPIPE and return EPIPE if ...
* (1) broken pipe (essentially, reader is gone)
* (2) FIFO is not open for reading
* return 0 if...
* (1) no stream
* (2) user write request is for 0 bytes and SW_SNDZERO is not set
* Note: SW_SNDZERO can't be set in fast mode
* While the stream is flow controlled....
* - if the NDELAY/NONBLOCK flag is set, return 0/EAGAIN.
* - unlock the fifonode and sleep waiting for a reader.
* - if a pipe and it has a mate, sleep waiting for its mate
* to read.
*/
/*ARGSUSED*/
static int
fifo_write(vnode_t *vp, uio_t *uiop, int ioflag, cred_t *crp,
caller_context_t *ct)
{
struct fifonode *fnp, *fn_dest;
fifolock_t *fn_lock;
struct stdata *stp;
int error = 0;
int write_size;
int size;
int fmode;
mblk_t *bp;
boolean_t hotread;
ASSERT(vp->v_stream);
uiop->uio_loffset = 0;
stp = vp->v_stream;
/*
* remember original number of bytes requested. Used to determine if
* we actually have written anything at all
*/
write_size = uiop->uio_resid;
/*
* only send zero-length messages if SW_SNDZERO is set
* Note: we will be in streams mode if SW_SNDZERO is set
* XXX this streams interface should not be exposed
*/
if ((write_size == 0) && !(stp->sd_wput_opt & SW_SNDZERO))
return (0);
fnp = VTOF(vp);
fn_lock = fnp->fn_lock;
fn_dest = fnp->fn_dest;
mutex_enter(&fn_lock->flk_lock);
TRACE_3(TR_FAC_FIFO, TR_FIFOWRITE_IN,
"fifo_write in:%p fnp %p size %d", vp, fnp, write_size);
/*
* oops, no readers, error
*/
if (fn_dest->fn_rcnt == 0 || fn_dest->fn_wcnt == 0) {
goto epipe;
}
/*
* if we are not in fast mode, let streams handle it
*/
if (!(fnp->fn_flag & FIFOFAST))
goto stream_mode;
fmode = uiop->uio_fmode & (FNDELAY|FNONBLOCK);
/* For pipes copy should not bypass cache */
uiop->uio_extflg |= UIO_COPY_CACHED;
do {
/*
* check to make sure we are not over high water mark
*/
while (fn_dest->fn_count >= Fifohiwat) {
/*
* Indicate that we have gone over high
* water mark
*/
/*
* if non-blocking, return
* only happens first time through loop
*/
if (fmode) {
fnp->fn_flag |= FIFOHIWATW;
if (uiop->uio_resid == write_size) {
mutex_exit(&fn_lock->flk_lock);
if (fmode & FNDELAY)
return (0);
else
return (EAGAIN);
}
goto done;
}
/*
* wait for things to drain
*/
fnp->fn_flag |= FIFOWANTW;
fnp->fn_wwaitcnt++;
TRACE_1(TR_FAC_FIFO, TR_FIFOWRITE_WAIT,
"fifo_write wait: %p", vp);
if (!cv_wait_sig_swap(&fnp->fn_wait_cv,
&fn_lock->flk_lock)) {
error = EINTR;
fnp->fn_wwaitcnt--;
fifo_wakereader(fn_dest, fn_lock);
goto done;
}
fnp->fn_wwaitcnt--;
TRACE_1(TR_FAC_FIFO, TR_FIFOWRITE_WAKE,
"fifo_write wake: %p", vp);
/*
* check to make sure we're still in fast mode
*/
if (!(fnp->fn_flag & FIFOFAST))
goto stream_mode;
/*
* make sure readers didn't go away
*/
if (fn_dest->fn_rcnt == 0 || fn_dest->fn_wcnt == 0) {
goto epipe;
}
}
/*
* If the write will put us over the high water mark,
* then we must break the message up into PIPE_BUF
* chunks to stay compliant with STREAMS
*/
if (uiop->uio_resid + fn_dest->fn_count > Fifohiwat)
size = MIN(uiop->uio_resid, PIPE_BUF);
else
size = uiop->uio_resid;
/*
* We don't need to hold flk_lock across the allocb() and
* uiomove(). However, on a multiprocessor machine where both
* the reader and writer thread are on cpu's, we must be
* careful to only drop the lock if there's data to be read.
* This forces threads entering fifo_read() to spin or block
* on flk_lock, rather than acquiring flk_lock only to
* discover there's no data to read and being forced to go
* back to sleep, only to be woken up microseconds later by
* this writer thread.
*/
hotread = fn_dest->fn_count > 0;
if (hotread) {
if (!fifo_stayfast_enter(fnp))
goto stream_mode;
mutex_exit(&fn_lock->flk_lock);
}
ASSERT(size != 0);
/*
* Align the mblk with the user data so that
* copying in the data can take advantage of
* the double word alignment
*/
if ((bp = allocb(size + 8, BPRI_MED)) == NULL) {
if (!hotread)
mutex_exit(&fn_lock->flk_lock);
error = strwaitbuf(size, BPRI_MED);
mutex_enter(&fn_lock->flk_lock);
if (hotread) {
/*
* As we dropped the mutex for a moment, we
* need to wake up any thread waiting to be
* allowed to go from fast mode to stream mode.
*/
fifo_stayfast_exit(fnp);
}
if (error != 0) {
goto done;
}
/*
* check to make sure we're still in fast mode
*/
if (!(fnp->fn_flag & FIFOFAST))
goto stream_mode;
/*
* make sure readers didn't go away
*/
if (fn_dest->fn_rcnt == 0 || fn_dest->fn_wcnt == 0) {
goto epipe;
}
/*
* some other thread could have gotten in
* need to go back and check hi water mark
*/
continue;
}
bp->b_rptr += ((uintptr_t)uiop->uio_iov->iov_base & 0x7);
bp->b_wptr = bp->b_rptr + size;
error = uiomove((caddr_t)bp->b_rptr, size, UIO_WRITE, uiop);
if (hotread) {
mutex_enter(&fn_lock->flk_lock);
/*
* As we dropped the mutex for a moment, we need to:
* - wake up any thread waiting to be allowed to go
* from fast mode to stream mode,
* - make sure readers didn't go away.
*/
fifo_stayfast_exit(fnp);
if (fn_dest->fn_rcnt == 0 || fn_dest->fn_wcnt == 0) {
freeb(bp);
goto epipe;
}
}
if (error != 0) {
freeb(bp);
goto done;
}
fn_dest->fn_count += size;
if (fn_dest->fn_mp != NULL) {
fn_dest->fn_tail->b_cont = bp;
fn_dest->fn_tail = bp;
} else {
fn_dest->fn_mp = fn_dest->fn_tail = bp;
/*
* This is the first bit of data; wake up any sleeping
* readers, processes blocked in poll, and those
* expecting a SIGPOLL.
*/
fifo_wakereader(fn_dest, fn_lock);
}
} while (uiop->uio_resid != 0);
goto done;
stream_mode:
/*
* streams mode
* let the stream head handle the write
*/
ASSERT(MUTEX_HELD(&fn_lock->flk_lock));
mutex_exit(&fn_lock->flk_lock);
TRACE_1(TR_FAC_FIFO,
TR_FIFOWRITE_STREAM, "fifo_write stream_mode:%p", vp);
error = strwrite(vp, uiop, crp);
mutex_enter(&fn_lock->flk_lock);
done:
/*
* update vnode modification and change times
* make sure there were no errors and some data was transferred
*/
if (error == 0 && write_size != uiop->uio_resid) {
time_t now = gethrestime_sec();
if (fnp->fn_flag & ISPIPE) {
fn_dest->fn_mtime = fn_dest->fn_ctime = now;
}
fnp->fn_mtime = fnp->fn_ctime = now;
} else if (fn_dest->fn_rcnt == 0 || fn_dest->fn_wcnt == 0) {
goto epipe;
}
TRACE_3(TR_FAC_FIFO, TR_FIFOWRITE_OUT,
"fifo_write out: vp %p error %d fnp %p", vp, error, fnp);
mutex_exit(&fn_lock->flk_lock);
return (error);
epipe:
error = EPIPE;
TRACE_3(TR_FAC_FIFO, TR_FIFOWRITE_OUT,
"fifo_write out: vp %p error %d fnp %p", vp, error, fnp);
mutex_exit(&fn_lock->flk_lock);
tsignal(curthread, SIGPIPE);
return (error);
}
/*ARGSUSED6*/
static int
fifo_ioctl(vnode_t *vp, int cmd, intptr_t arg, int mode,
cred_t *cr, int *rvalp, caller_context_t *ct)
{
/*
* Just a quick check
* Once we go to streams mode we don't ever revert back
* So we do this quick check so as not to incur the overhead
* associated with acquiring the lock
*/
return ((VTOF(vp)->fn_flag & FIFOFAST) ?
fifo_fastioctl(vp, cmd, arg, mode, cr, rvalp) :
fifo_strioctl(vp, cmd, arg, mode, cr, rvalp));
}
static int
fifo_fastioctl(vnode_t *vp, int cmd, intptr_t arg, int mode,
cred_t *cr, int *rvalp)
{
fifonode_t *fnp = VTOF(vp);
fifonode_t *fn_dest;
int error = 0;
fifolock_t *fn_lock = fnp->fn_lock;
int cnt;
/*
* tty operations not allowed
*/
if (((cmd & IOCTYPE) == LDIOC) ||
((cmd & IOCTYPE) == tIOC) ||
((cmd & IOCTYPE) == TIOC)) {
return (EINVAL);
}
mutex_enter(&fn_lock->flk_lock);
if (!(fnp->fn_flag & FIFOFAST)) {
goto stream_mode;
}
switch (cmd) {
/*
* Things we can't handle
* These will switch us to streams mode.
*/
default:
case I_STR:
case I_SRDOPT:
case I_PUSH:
case I_FDINSERT:
case I_SENDFD:
case I_RECVFD:
case I_E_RECVFD:
case I_ATMARK:
case I_CKBAND:
case I_GETBAND:
case I_SWROPT:
goto turn_fastoff;
/*
* Things that don't do damage
* These things don't adjust the state of the
* stream head (i_setcltime does, but we don't care)
*/
case I_FIND:
case I_GETSIG:
case FIONBIO:
case FIOASYNC:
case I_GRDOPT: /* probably should not get this, but no harm */
case I_GWROPT:
case I_LIST:
case I_SETCLTIME:
case I_GETCLTIME:
mutex_exit(&fn_lock->flk_lock);
return (strioctl(vp, cmd, arg, mode, U_TO_K, cr, rvalp));
case I_CANPUT:
/*
* We can only handle normal band canputs.
* XXX : We could just always go to stream mode; after all
* canput is a streams semantics type thing
*/
if (arg != 0) {
goto turn_fastoff;
}
*rvalp = (fnp->fn_dest->fn_count < Fifohiwat) ? 1 : 0;
mutex_exit(&fn_lock->flk_lock);
return (0);
case I_NREAD:
/*
* This may seem a bit silly for non-streams semantics,
* (After all, if they really want a message, they'll
* probably use getmsg() anyway). but it doesn't hurt
*/
error = copyout((caddr_t)&fnp->fn_count, (caddr_t)arg,
sizeof (cnt));
if (error == 0) {
*rvalp = (fnp->fn_count == 0) ? 0 : 1;
}
break;
case FIORDCHK:
*rvalp = fnp->fn_count;
break;
case I_PEEK:
{
STRUCT_DECL(strpeek, strpeek);
struct uio uio;
struct iovec iov;
int count;
mblk_t *bp;
int len;
STRUCT_INIT(strpeek, mode);
if (fnp->fn_count == 0) {
*rvalp = 0;
break;
}
error = copyin((caddr_t)arg, STRUCT_BUF(strpeek),
STRUCT_SIZE(strpeek));
if (error)
break;
/*
* can't have any high priority message when in fast mode
*/
if (STRUCT_FGET(strpeek, flags) & RS_HIPRI) {
*rvalp = 0;
break;
}
len = STRUCT_FGET(strpeek, databuf.maxlen);
if (len <= 0) {
STRUCT_FSET(strpeek, databuf.len, len);
} else {
iov.iov_base = STRUCT_FGETP(strpeek, databuf.buf);
iov.iov_len = len;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_loffset = 0;
uio.uio_segflg = UIO_USERSPACE;
uio.uio_fmode = 0;
/* For pipes copy should not bypass cache */
uio.uio_extflg = UIO_COPY_CACHED;
uio.uio_resid = iov.iov_len;
count = fnp->fn_count;
bp = fnp->fn_mp;
while (count > 0 && uio.uio_resid) {
cnt = MIN(uio.uio_resid, MBLKL(bp));
if ((error = uiomove((char *)bp->b_rptr, cnt,
UIO_READ, &uio)) != 0) {
break;
}
count -= cnt;
bp = bp->b_cont;
}
STRUCT_FSET(strpeek, databuf.len, len - uio.uio_resid);
}
STRUCT_FSET(strpeek, flags, 0);
STRUCT_FSET(strpeek, ctlbuf.len, -1);
error = copyout(STRUCT_BUF(strpeek), (caddr_t)arg,
STRUCT_SIZE(strpeek));
if (error == 0 && len >= 0)
*rvalp = 1;
break;
}
case FIONREAD:
/*
* let user know total number of bytes in message queue
*/
error = copyout((caddr_t)&fnp->fn_count, (caddr_t)arg,
sizeof (fnp->fn_count));
if (error == 0)
*rvalp = 0;
break;
case I_SETSIG:
/*
* let streams set up the signal masking for us
* we just check to see if it's set
* XXX : this interface should not be visible
* i.e. STREAM's framework is exposed.
*/
error = strioctl(vp, cmd, arg, mode, U_TO_K, cr, rvalp);
if (vp->v_stream->sd_sigflags & (S_INPUT|S_RDNORM|S_WRNORM))
fnp->fn_flag |= FIFOSETSIG;
else
fnp->fn_flag &= ~FIFOSETSIG;
break;
case I_FLUSH:
/*
* flush them message queues
*/
if (arg & ~FLUSHRW) {
error = EINVAL;
break;
}
if (arg & FLUSHR) {
fifo_fastflush(fnp);
}
fn_dest = fnp->fn_dest;
if ((arg & FLUSHW)) {
fifo_fastflush(fn_dest);
}
/*
* wake up any sleeping readers or writers
* (waking readers probably doesn't make sense, but it
* doesn't hurt; i.e. we just got rid of all the data
* what's to read ?)
*/
if (fn_dest->fn_flag & (FIFOWANTW | FIFOWANTR)) {
fn_dest->fn_flag &= ~(FIFOWANTW | FIFOWANTR);
cv_broadcast(&fn_dest->fn_wait_cv);
}
*rvalp = 0;
break;
/*
* Since no band data can ever get on a fifo in fast mode
* just return 0.
*/
case I_FLUSHBAND:
error = 0;
*rvalp = 0;
break;
/*
* invalid calls for stream head or fifos
*/
case I_POP: /* shouldn't happen */
case I_LOOK:
case I_LINK:
case I_PLINK:
case I_UNLINK:
case I_PUNLINK:
/*
* more invalid tty type of ioctls
*/
case SRIOCSREDIR:
case SRIOCISREDIR:
error = EINVAL;
break;
}
mutex_exit(&fn_lock->flk_lock);
return (error);
turn_fastoff:
fifo_fastoff(fnp);
stream_mode:
/*
* streams mode
*/
mutex_exit(&fn_lock->flk_lock);
return (fifo_strioctl(vp, cmd, arg, mode, cr, rvalp));
}
/*
* FIFO is in STREAMS mode; STREAMS framework does most of the work.
*/
static int
fifo_strioctl(vnode_t *vp, int cmd, intptr_t arg, int mode,
cred_t *cr, int *rvalp)
{
fifonode_t *fnp = VTOF(vp);
int error;
fifolock_t *fn_lock;
if (cmd == _I_GETPEERCRED) {
if (mode == FKIOCTL && fnp->fn_pcredp != NULL) {
k_peercred_t *kp = (k_peercred_t *)arg;
crhold(fnp->fn_pcredp);
kp->pc_cr = fnp->fn_pcredp;
kp->pc_cpid = fnp->fn_cpid;
return (0);
} else {
return (ENOTSUP);
}
}
error = strioctl(vp, cmd, arg, mode, U_TO_K, cr, rvalp);
switch (cmd) {
/*
* The FIFOSEND flag is set to inform other processes that a file
* descriptor is pending at the stream head of this pipe.
* The flag is cleared and the sending process is awoken when
* this process has completed receiving the file descriptor.
* XXX This could become out of sync if the process does I_SENDFDs
* and opens on connld attached to the same pipe.
*/
case I_RECVFD:
case I_E_RECVFD:
if (error == 0) {
fn_lock = fnp->fn_lock;
mutex_enter(&fn_lock->flk_lock);
if (fnp->fn_flag & FIFOSEND) {
fnp->fn_flag &= ~FIFOSEND;
cv_broadcast(&fnp->fn_dest->fn_wait_cv);
}
mutex_exit(&fn_lock->flk_lock);
}
break;
default:
break;
}
return (error);
}
/*
* If shadowing a vnode (FIFOs), apply the VOP_GETATTR to the shadowed
* vnode to Obtain the node information. If not shadowing (pipes), obtain
* the node information from the credentials structure.
*/
int
fifo_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *crp,
caller_context_t *ct)
{
int error = 0;
fifonode_t *fnp = VTOF(vp);
queue_t *qp;
qband_t *bandp;
fifolock_t *fn_lock = fnp->fn_lock;
if (fnp->fn_realvp) {
/*
* for FIFOs or mounted pipes
*/
if (error = VOP_GETATTR(fnp->fn_realvp, vap, flags, crp, ct))
return (error);
mutex_enter(&fn_lock->flk_lock);
/* set current times from fnode, even if older than vnode */
vap->va_atime.tv_sec = fnp->fn_atime;
vap->va_atime.tv_nsec = 0;
vap->va_mtime.tv_sec = fnp->fn_mtime;
vap->va_mtime.tv_nsec = 0;
vap->va_ctime.tv_sec = fnp->fn_ctime;
vap->va_ctime.tv_nsec = 0;
} else {
/*
* for non-attached/ordinary pipes
*/
vap->va_mode = 0;
mutex_enter(&fn_lock->flk_lock);
vap->va_atime.tv_sec = fnp->fn_atime;
vap->va_atime.tv_nsec = 0;
vap->va_mtime.tv_sec = fnp->fn_mtime;
vap->va_mtime.tv_nsec = 0;
vap->va_ctime.tv_sec = fnp->fn_ctime;
vap->va_ctime.tv_nsec = 0;
vap->va_uid = crgetuid(crp);
vap->va_gid = crgetgid(crp);
vap->va_nlink = 0;
vap->va_fsid = fifodev;
vap->va_nodeid = (ino64_t)fnp->fn_ino;
vap->va_rdev = 0;
}
vap->va_type = VFIFO;
vap->va_blksize = PIPE_BUF;
/*
* Size is number of un-read bytes at the stream head and
* nblocks is the unread bytes expressed in blocks.
*/
if (vp->v_stream && (fnp->fn_flag & FIFOISOPEN)) {
if ((fnp->fn_flag & FIFOFAST)) {
vap->va_size = (u_offset_t)fnp->fn_count;
} else {
qp = RD((strvp2wq(vp)));
vap->va_size = (u_offset_t)qp->q_count;
if (qp->q_nband != 0) {
mutex_enter(QLOCK(qp));
for (bandp = qp->q_bandp; bandp;
bandp = bandp->qb_next)
vap->va_size += bandp->qb_count;
mutex_exit(QLOCK(qp));
}
}
vap->va_nblocks = (fsblkcnt64_t)btod(vap->va_size);
} else {
vap->va_size = (u_offset_t)0;
vap->va_nblocks = (fsblkcnt64_t)0;
}
mutex_exit(&fn_lock->flk_lock);
vap->va_seq = 0;
return (0);
}
/*
* If shadowing a vnode, apply the VOP_SETATTR to it, and to the fnode.
* Otherwise, set the time and return 0.
*/
int
fifo_setattr(
vnode_t *vp,
vattr_t *vap,
int flags,
cred_t *crp,
caller_context_t *ctp)
{
fifonode_t *fnp = VTOF(vp);
int error = 0;
fifolock_t *fn_lock;
if (fnp->fn_realvp)
error = VOP_SETATTR(fnp->fn_realvp, vap, flags, crp, ctp);
if (error == 0) {
fn_lock = fnp->fn_lock;
mutex_enter(&fn_lock->flk_lock);
if (vap->va_mask & AT_ATIME)
fnp->fn_atime = vap->va_atime.tv_sec;
if (vap->va_mask & AT_MTIME)
fnp->fn_mtime = vap->va_mtime.tv_sec;
fnp->fn_ctime = gethrestime_sec();
mutex_exit(&fn_lock->flk_lock);
}
return (error);
}
/*
* If shadowing a vnode, apply VOP_ACCESS to it.
* Otherwise, return 0 (allow all access).
*/
int
fifo_access(vnode_t *vp, int mode, int flags, cred_t *crp, caller_context_t *ct)
{
if (VTOF(vp)->fn_realvp)
return (VOP_ACCESS(VTOF(vp)->fn_realvp, mode, flags, crp, ct));
else
return (0);
}
/*
* This can be called if creat or an open with O_CREAT is done on the root
* of a lofs mount where the mounted entity is a fifo.
*/
/*ARGSUSED*/
static int
fifo_create(struct vnode *dvp, char *name, vattr_t *vap, enum vcexcl excl,
int mode, struct vnode **vpp, struct cred *cr, int flag,
caller_context_t *ct, vsecattr_t *vsecp)
{
int error;
ASSERT(dvp && (dvp->v_flag & VROOT) && *name == '\0');
if (excl == NONEXCL) {
if (mode && (error = fifo_access(dvp, mode, 0, cr, ct)))
return (error);
VN_HOLD(dvp);
return (0);
}
return (EEXIST);
}
/*
* If shadowing a vnode, apply the VOP_FSYNC to it.
* Otherwise, return 0.
*/
int
fifo_fsync(vnode_t *vp, int syncflag, cred_t *crp, caller_context_t *ct)
{
fifonode_t *fnp = VTOF(vp);
vattr_t va;
if (fnp->fn_realvp == NULL)
return (0);
bzero((caddr_t)&va, sizeof (va));
va.va_mask = AT_MTIME | AT_ATIME;
if (VOP_GETATTR(fnp->fn_realvp, &va, 0, crp, ct) == 0) {
va.va_mask = 0;
if (fnp->fn_mtime > va.va_mtime.tv_sec) {
va.va_mtime.tv_sec = fnp->fn_mtime;
va.va_mask = AT_MTIME;
}
if (fnp->fn_atime > va.va_atime.tv_sec) {
va.va_atime.tv_sec = fnp->fn_atime;
va.va_mask |= AT_ATIME;
}
if (va.va_mask != 0)
(void) VOP_SETATTR(fnp->fn_realvp, &va, 0, crp, ct);
}
return (VOP_FSYNC(fnp->fn_realvp, syncflag, crp, ct));
}
/*
* Called when the upper level no longer holds references to the
* vnode. Sync the file system and free the fifonode.
*/
void
fifo_inactive(vnode_t *vp, cred_t *crp, caller_context_t *ct)
{
fifonode_t *fnp;
fifolock_t *fn_lock;
mutex_enter(&ftable_lock);
mutex_enter(&vp->v_lock);
ASSERT(vp->v_count >= 1);
if (--vp->v_count != 0) {
/*
* Somebody accessed the fifo before we got a chance to
* remove it. They will remove it when they do a vn_rele.
*/
mutex_exit(&vp->v_lock);
mutex_exit(&ftable_lock);
return;
}
mutex_exit(&vp->v_lock);
fnp = VTOF(vp);
/*
* remove fifo from fifo list so that no other process
* can grab it.
*/
if (fnp->fn_realvp) {
(void) fiforemove(fnp);
mutex_exit(&ftable_lock);
(void) fifo_fsync(vp, FSYNC, crp, ct);
VN_RELE(fnp->fn_realvp);
vp->v_vfsp = NULL;
} else
mutex_exit(&ftable_lock);
fn_lock = fnp->fn_lock;
mutex_enter(&fn_lock->flk_lock);
ASSERT(vp->v_stream == NULL);
ASSERT(vp->v_count == 0);
/*
* if this is last reference to the lock, then we can
* free everything up.
*/
if (--fn_lock->flk_ref == 0) {
mutex_exit(&fn_lock->flk_lock);
ASSERT(fnp->fn_open == 0);
ASSERT(fnp->fn_dest->fn_open == 0);
if (fnp->fn_mp) {
freemsg(fnp->fn_mp);
fnp->fn_mp = NULL;
fnp->fn_count = 0;
}
if (fnp->fn_pcredp != NULL) {
crfree(fnp->fn_pcredp);
fnp->fn_pcredp = NULL;
}
if (fnp->fn_flag & ISPIPE) {
fifonode_t *fn_dest = fnp->fn_dest;
vp = FTOV(fn_dest);
if (fn_dest->fn_mp) {
freemsg(fn_dest->fn_mp);
fn_dest->fn_mp = NULL;
fn_dest->fn_count = 0;
}
if (fn_dest->fn_pcredp != NULL) {
crfree(fn_dest->fn_pcredp);
fn_dest->fn_pcredp = NULL;
}
kmem_cache_free(pipe_cache, (fifodata_t *)fn_lock);
} else
kmem_cache_free(fnode_cache, (fifodata_t *)fn_lock);
} else {
mutex_exit(&fn_lock->flk_lock);
}
}
/*
* If shadowing a vnode, apply the VOP_FID to it.
* Otherwise, return EINVAL.
*/
int
fifo_fid(vnode_t *vp, fid_t *fidfnp, caller_context_t *ct)
{
if (VTOF(vp)->fn_realvp)
return (VOP_FID(VTOF(vp)->fn_realvp, fidfnp, ct));
else
return (EINVAL);
}
/*
* Lock a fifonode.
*/
/* ARGSUSED */
int
fifo_rwlock(vnode_t *vp, int write_lock, caller_context_t *ctp)
{
return (-1);
}
/*
* Unlock a fifonode.
*/
/* ARGSUSED */
void
fifo_rwunlock(vnode_t *vp, int write_lock, caller_context_t *ctp)
{
}
/*
* Return error since seeks are not allowed on pipes.
*/
/*ARGSUSED*/
int
fifo_seek(vnode_t *vp, offset_t ooff, offset_t *noffp, caller_context_t *ct)
{
return (ESPIPE);
}
/*
* If there is a realvp associated with vp, return it.
*/
int
fifo_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
{
vnode_t *rvp;
if ((rvp = VTOF(vp)->fn_realvp) != NULL) {
vp = rvp;
if (VOP_REALVP(vp, &rvp, ct) == 0)
vp = rvp;
}
*vpp = vp;
return (0);
}
/*
* Poll for interesting events on a stream pipe
*/
/* ARGSUSED */
int
fifo_poll(vnode_t *vp, short events, int anyyet, short *reventsp,
pollhead_t **phpp, caller_context_t *ct)
{
fifonode_t *fnp, *fn_dest;
fifolock_t *fn_lock;
int retevents;
struct stdata *stp;
ASSERT(vp->v_stream != NULL);
stp = vp->v_stream;
retevents = 0;
fnp = VTOF(vp);
fn_dest = fnp->fn_dest;
fn_lock = fnp->fn_lock;
polllock(&stp->sd_pollist, &fn_lock->flk_lock);
/*
* see if FIFO/pipe open
*/
if ((fnp->fn_flag & FIFOISOPEN) == 0) {
if (((events & (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND)) &&
fnp->fn_rcnt == 0) ||
((events & (POLLWRNORM | POLLWRBAND)) &&
fnp->fn_wcnt == 0)) {
mutex_exit(&fnp->fn_lock->flk_lock);
*reventsp = POLLERR;
return (0);
}
}
/*
* if not in fast mode, let the stream head take care of it
*/
if (!(fnp->fn_flag & FIFOFAST)) {
mutex_exit(&fnp->fn_lock->flk_lock);
goto stream_mode;
}
/*
* If this is a pipe.. check to see if the other
* end is gone. If we are a fifo, check to see
* if write end is gone.
*/
if ((fnp->fn_flag & ISPIPE) && (fn_dest->fn_open == 0)) {
retevents = POLLHUP;
} else if ((fnp->fn_flag & (FIFOCLOSE | ISPIPE)) == FIFOCLOSE &&
(fn_dest->fn_wcnt == 0)) {
/*
* no writer at other end.
* it was closed (versus yet to be opened)
*/
retevents = POLLHUP;
} else if (events & (POLLWRNORM | POLLWRBAND)) {
if (events & POLLWRNORM) {
if (fn_dest->fn_count < Fifohiwat)
retevents = POLLWRNORM;
else
fnp->fn_flag |= FIFOHIWATW;
}
/*
* This is always true for fast pipes
* (Note: will go to STREAMS mode if band data is written)
*/
if (events & POLLWRBAND)
retevents |= POLLWRBAND;
}
if (events & (POLLIN | POLLRDNORM)) {
if (fnp->fn_count)
retevents |= (events & (POLLIN | POLLRDNORM));
}
/*
* if we happened to get something, return
*/
if ((*reventsp = (short)retevents) != 0) {
mutex_exit(&fnp->fn_lock->flk_lock);
return (0);
}
/*
* If poll() has not found any events yet, set up event cell
* to wake up the poll if a requested event occurs on this
* pipe/fifo.
*/
if (!anyyet) {
if (events & POLLWRNORM)
fnp->fn_flag |= FIFOPOLLW;
if (events & (POLLIN | POLLRDNORM))
fnp->fn_flag |= FIFOPOLLR;
if (events & POLLRDBAND)
fnp->fn_flag |= FIFOPOLLRBAND;
/*
* XXX Don't like exposing this from streams
*/
*phpp = &stp->sd_pollist;
}
mutex_exit(&fnp->fn_lock->flk_lock);
return (0);
stream_mode:
return (strpoll(stp, events, anyyet, reventsp, phpp));
}
/*
* POSIX pathconf() support.
*/
/* ARGSUSED */
int
fifo_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
caller_context_t *ct)
{
ulong_t val;
int error = 0;
switch (cmd) {
case _PC_LINK_MAX:
val = MAXLINK;
break;
case _PC_MAX_CANON:
val = MAX_CANON;
break;
case _PC_MAX_INPUT:
val = MAX_INPUT;
break;
case _PC_NAME_MAX:
error = EINVAL;
break;
case _PC_PATH_MAX:
case _PC_SYMLINK_MAX:
val = MAXPATHLEN;
break;
case _PC_PIPE_BUF:
val = PIPE_BUF;
break;
case _PC_NO_TRUNC:
if (vp->v_vfsp->vfs_flag & VFS_NOTRUNC)
val = 1; /* NOTRUNC is enabled for vp */
else
val = (ulong_t)-1;
break;
case _PC_VDISABLE:
val = _POSIX_VDISABLE;
break;
case _PC_CHOWN_RESTRICTED:
if (rstchown)
val = rstchown; /* chown restricted enabled */
else
val = (ulong_t)-1;
break;
case _PC_FILESIZEBITS:
val = (ulong_t)-1;
break;
default:
if (VTOF(vp)->fn_realvp)
error = VOP_PATHCONF(VTOF(vp)->fn_realvp, cmd,
&val, cr, ct);
else
error = EINVAL;
break;
}
if (error == 0)
*valp = val;
return (error);
}
/*
* If shadowing a vnode, apply VOP_SETSECATTR to it.
* Otherwise, return NOSYS.
*/
int
fifo_setsecattr(struct vnode *vp, vsecattr_t *vsap, int flag, struct cred *crp,
caller_context_t *ct)
{
int error;
/*
* The acl(2) system call tries to grab the write lock on the
* file when setting an ACL, but fifofs does not implement
* VOP_RWLOCK or VOP_RWUNLOCK, so we do it here instead.
*/
if (VTOF(vp)->fn_realvp) {
(void) VOP_RWLOCK(VTOF(vp)->fn_realvp, V_WRITELOCK_TRUE, ct);
error = VOP_SETSECATTR(VTOF(vp)->fn_realvp, vsap, flag,
crp, ct);
VOP_RWUNLOCK(VTOF(vp)->fn_realvp, V_WRITELOCK_TRUE, ct);
return (error);
} else
return (fs_nosys());
}
/*
* If shadowing a vnode, apply VOP_GETSECATTR to it. Otherwise, fabricate
* an ACL from the permission bits that fifo_getattr() makes up.
*/
int
fifo_getsecattr(struct vnode *vp, vsecattr_t *vsap, int flag, struct cred *crp,
caller_context_t *ct)
{
if (VTOF(vp)->fn_realvp)
return (VOP_GETSECATTR(VTOF(vp)->fn_realvp, vsap, flag,
crp, ct));
else
return (fs_fab_acl(vp, vsap, flag, crp, ct));
}
/*
* Set the FIFOSTAYFAST flag so nobody can turn the fifo into stream mode.
* If the flag is already set then wait until it is removed - releasing
* the lock.
* If the fifo switches into stream mode while we are waiting, return failure.
*/
static boolean_t
fifo_stayfast_enter(fifonode_t *fnp)
{
ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
while (fnp->fn_flag & FIFOSTAYFAST) {
fnp->fn_flag |= FIFOWAITMODE;
cv_wait(&fnp->fn_wait_cv, &fnp->fn_lock->flk_lock);
fnp->fn_flag &= ~FIFOWAITMODE;
}
if (!(fnp->fn_flag & FIFOFAST))
return (B_FALSE);
fnp->fn_flag |= FIFOSTAYFAST;
return (B_TRUE);
}
/*
* Unset the FIFOSTAYFAST flag and notify anybody waiting for this flag
* to be removed:
* - threads wanting to turn into stream mode waiting in fifo_fastoff(),
* - other writers threads waiting in fifo_stayfast_enter().
*/
static void
fifo_stayfast_exit(fifonode_t *fnp)
{
fifonode_t *fn_dest = fnp->fn_dest;
ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
fnp->fn_flag &= ~FIFOSTAYFAST;
if (fnp->fn_flag & FIFOWAITMODE)
cv_broadcast(&fnp->fn_wait_cv);
if ((fnp->fn_flag & ISPIPE) && (fn_dest->fn_flag & FIFOWAITMODE))
cv_broadcast(&fn_dest->fn_wait_cv);
}