Introduce `fd_mtx' mutex(9) and use it for `fd_fbufs_in' fuse buffers
queue and `fd_rklist' knotes list protection.
Index: sys/miscfs/fuse/fuse_device.c
===================================================================
RCS file: /cvs/src/sys/miscfs/fuse/fuse_device.c,v
retrieving revision 1.39
diff -u -p -r1.39 fuse_device.c
--- sys/miscfs/fuse/fuse_device.c 8 Sep 2023 20:00:28 -0000 1.39
+++ sys/miscfs/fuse/fuse_device.c 27 Sep 2023 13:05:55 -0000
@@ -19,13 +19,14 @@
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
+#include <sys/event.h>
#include <sys/malloc.h>
#include <sys/mount.h>
+#include <sys/mutex.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/vnode.h>
#include <sys/fusebuf.h>
-#include <sys/selinfo.h>
#include "fusefs_node.h"
#include "fusefs.h"
@@ -36,18 +37,24 @@
#define DPRINTF(fmt, arg...)
#endif
+/*
+ * Locks used to protect struct members and global data
+ * m fd_mtx
+ */
+
SIMPLEQ_HEAD(fusebuf_head, fusebuf);
struct fuse_d {
+ struct mutex fd_mtx;
struct fusefs_mnt *fd_fmp;
int fd_unit;
/*fusebufs queues*/
- struct fusebuf_head fd_fbufs_in;
+ struct fusebuf_head fd_fbufs_in; /* [m] */
struct fusebuf_head fd_fbufs_wait;
/* kq fields */
- struct selinfo fd_rsel;
+ struct klist fd_rklist; /* [m] */
LIST_ENTRY(fuse_d) fd_list;
};
@@ -67,12 +74,16 @@ int fusewrite(dev_t, struct uio *, int);
int fusekqfilter(dev_t dev, struct knote *kn);
int filt_fuse_read(struct knote *, long);
void filt_fuse_rdetach(struct knote *);
+int filt_fuse_modify(struct kevent *, struct knote *);
+int filt_fuse_process(struct knote *, struct kevent *);
static const struct filterops fuse_rd_filtops = {
- .f_flags = FILTEROP_ISFD,
+ .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
.f_attach = NULL,
.f_detach = filt_fuse_rdetach,
.f_event = filt_fuse_read,
+ .f_modify = filt_fuse_modify,
+ .f_process = filt_fuse_process,
};
#ifdef FUSE_DEBUG
@@ -142,6 +153,7 @@ fuse_device_cleanup(dev_t dev)
/* clear FIFO IN */
lprev = NULL;
+ mtx_enter(&fd->fd_mtx);
SIMPLEQ_FOREACH_SAFE(f, &fd->fd_fbufs_in, fb_next, ftmp) {
DPRINTF("cleanup unprocessed msg in sc_fbufs_in\n");
if (lprev == NULL)
@@ -155,6 +167,7 @@ fuse_device_cleanup(dev_t dev)
wakeup(f);
lprev = f;
}
+ mtx_leave(&fd->fd_mtx);
/* clear FIFO WAIT*/
lprev = NULL;
@@ -182,9 +195,11 @@ fuse_device_queue_fbuf(dev_t dev, struct
if (fd == NULL)
return;
+ mtx_enter(&fd->fd_mtx);
SIMPLEQ_INSERT_TAIL(&fd->fd_fbufs_in, fbuf, fb_next);
+ knote_locked(&fd->fd_rklist, 0);
+ mtx_leave(&fd->fd_mtx);
stat_fbufs_in++;
- selwakeup(&fd->fd_rsel);
}
void
@@ -221,6 +236,9 @@ fuseopen(dev_t dev, int flags, int fmt,
fd->fd_unit = unit;
SIMPLEQ_INIT(&fd->fd_fbufs_in);
SIMPLEQ_INIT(&fd->fd_fbufs_wait);
+ mtx_init(&fd->fd_mtx, IPL_MPFLOOR);
+ klist_init_mutex(&fd->fd_rklist, &fd->fd_mtx);
+
LIST_INSERT_HEAD(&fuse_d_list, fd, fd_list);
stat_opened_fusedev++;
@@ -278,6 +296,7 @@ fuseioctl(dev_t dev, u_long cmd, caddr_t
ioexch = (struct fb_ioctl_xch *)addr;
/* Looking for uuid in fd_fbufs_in */
+ mtx_enter(&fd->fd_mtx);
SIMPLEQ_FOREACH(fbuf, &fd->fd_fbufs_in, fb_next) {
if (fbuf->fb_uuid == ioexch->fbxch_uuid)
break;
@@ -285,6 +304,7 @@ fuseioctl(dev_t dev, u_long cmd, caddr_t
lastfbuf = fbuf;
}
if (fbuf == NULL) {
+ mtx_leave(&fd->fd_mtx);
printf("fuse: Cannot find fusebuf\n");
return (EINVAL);
}
@@ -295,6 +315,8 @@ fuseioctl(dev_t dev, u_long cmd, caddr_t
else
SIMPLEQ_REMOVE_AFTER(&fd->fd_fbufs_in, lastfbuf,
fb_next);
+ mtx_leave(&fd->fd_mtx);
+
stat_fbufs_in--;
/* Do not handle fbufs with bad len */
@@ -389,13 +411,17 @@ fuseread(dev_t dev, struct uio *uio, int
if (fd == NULL)
return (ENXIO);
+ mtx_enter(&fd->fd_mtx);
if (SIMPLEQ_EMPTY(&fd->fd_fbufs_in)) {
+ mtx_leave(&fd->fd_mtx);
+
if (ioflag & O_NONBLOCK)
return (EAGAIN);
goto end;
}
fbuf = SIMPLEQ_FIRST(&fd->fd_fbufs_in);
+ mtx_leave(&fd->fd_mtx);
/* We get the whole fusebuf or nothing */
if (uio->uio_resid != FUSEBUFSIZE)
@@ -419,7 +445,9 @@ fuseread(dev_t dev, struct uio *uio, int
/* Remove the fbuf if it does not contains data */
if (fbuf->fb_len == 0) {
+ mtx_enter(&fd->fd_mtx);
SIMPLEQ_REMOVE_HEAD(&fd->fd_fbufs_in, fb_next);
+ mtx_leave(&fd->fd_mtx);
stat_fbufs_in--;
SIMPLEQ_INSERT_TAIL(&fd->fd_fbufs_wait, fbuf, fb_next);
stat_fbufs_wait++;
@@ -519,7 +547,7 @@ fusekqfilter(dev_t dev, struct knote *kn
switch (kn->kn_filter) {
case EVFILT_READ:
- klist = &fd->fd_rsel.si_note;
+ klist = &fd->fd_rklist;
kn->kn_fop = &fuse_rd_filtops;
break;
case EVFILT_WRITE:
@@ -530,7 +558,7 @@ fusekqfilter(dev_t dev, struct knote *kn
kn->kn_hook = fd;
- klist_insert_locked(klist, kn);
+ klist_insert(klist, kn);
return (0);
}
@@ -539,9 +567,9 @@ void
filt_fuse_rdetach(struct knote *kn)
{
struct fuse_d *fd = kn->kn_hook;
- struct klist *klist = &fd->fd_rsel.si_note;
+ struct klist *klist = &fd->fd_rklist;
- klist_remove_locked(klist, kn);
+ klist_remove(klist, kn);
}
int
@@ -554,4 +582,30 @@ filt_fuse_read(struct knote *kn, long hi
event = 1;
return (event);
+}
+
+int
+filt_fuse_modify(struct kevent *kev, struct knote *kn)
+{
+ struct fuse_d *fd = kn->kn_hook;
+ int active;
+
+ mtx_enter(&fd->fd_mtx);
+ active = knote_modify(kev, kn);
+ mtx_leave(&fd->fd_mtx);
+
+ return (active);
+}
+
+int
+filt_fuse_process(struct knote *kn, struct kevent *kev)
+{
+ struct fuse_d *fd = kn->kn_hook;
+ int active;
+
+ mtx_enter(&fd->fd_mtx);
+ active = knote_process(kn, kev);
+ mtx_leave(&fd->fd_mtx);
+
+ return (active);
}
