d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make SIGSTOP working for sleeps done while waiting for fifo readers or

Browse Source 
writers in open(2), when the fifo is located on an NFS mount.

Reported by:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
This commit is contained in:
Konstantin Belousov 2015-01-18 15:03:26 +00:00
parent 9cac79b378
commit e3612a4c1f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=277321
3 changed files with 13 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
sys/fs/fifofs/fifo_vnops.c
View File

@ -137,7 +137,7 @@ fifo_open(ap)
struct thread *td;
struct fifoinfo *fip;
struct pipe *fpipe;
int error;
int error, stops_deferred;
vp = ap->a_vp;
fp = ap->a_fp;
@ -188,8 +188,11 @@ fifo_open(ap)
if ((ap->a_mode & O_NONBLOCK) == 0) {
if ((ap->a_mode & FREAD) && fip->fi_writers == 0) {
VOP_UNLOCK(vp, 0);
stops_deferred = sigallowstop();
error = msleep(&fip->fi_readers, PIPE_MTX(fpipe),
PDROP | PCATCH | PSOCK, "fifoor", 0);
if (stops_deferred)
sigdeferstop();
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (error) {
fip->fi_readers--;
@ -212,8 +215,11 @@ fifo_open(ap)
}
if ((ap->a_mode & FWRITE) && fip->fi_readers == 0) {
VOP_UNLOCK(vp, 0);
stops_deferred = sigallowstop();
error = msleep(&fip->fi_writers, PIPE_MTX(fpipe),
PDROP | PCATCH | PSOCK, "fifoow", 0);
if (stops_deferred)
sigdeferstop();
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (error) {
fip->fi_writers--;

7
sys/kern/kern_sig.c
View File

@ -2587,15 +2587,18 @@ sigdeferstop(void)
* not immediately suspend if a stop was posted. Instead, the thread
* will suspend either via ast() or a subsequent interruptible sleep.
*/
void
sigallowstop()
int
sigallowstop(void)
{
struct thread *td;
int prev;
td = curthread;
thread_lock(td);
prev = (td->td_flags & TDF_SBDRY) != 0;
td->td_flags &= ~TDF_SBDRY;
thread_unlock(td);
return (prev);
}
/*

2
sys/sys/signalvar.h
View File

@ -325,7 +325,7 @@ extern struct mtx sigio_lock;
int cursig(struct thread *td);
int sigdeferstop(void);
void sigallowstop(void);
int sigallowstop(void);
void execsigs(struct proc *p);
void gsignal(int pgid, int sig, ksiginfo_t *ksi);
void killproc(struct proc *p, char *why);