After recent reboot related improvements, I have some familiarity with
tricking the vnode layer into a stable state.
This should settle filesystems "clean" onto disk. If one does a
suspend and then runs out of battery.. or experiences a crash or out
of battery during a hibernate, the filesystems will now be in a clean
state and not require an fsck.
After the screen blanks, there may be 1-2 seconds more IO than before.
Those weren't hitting the platter, but remained in the vfs softlayer
through to resume. The new situation is much better.
I have wanted to solve this problem for years..
There may be problems with softraid again, we'll need to see. I
haven't tested softdep but the correct syncronization functions appear
to be called. USB sticks get detached during the suspend phase, and
are as good as before.
This isn't quite finished, and I have a few more tricks up my sleeve,
and the "vfs_stalling" global will probably become a parameter for
VFS_SYNC()...
I'd appreciate reports about how well it delivers and if any new
problems show up.
Index: kern/vfs_subr.c
===================================================================
RCS file: /cvs/src/sys/kern/vfs_subr.c,v
retrieving revision 1.265
diff -u -p -u -r1.265 vfs_subr.c
--- kern/vfs_subr.c 14 Dec 2017 20:23:15 -0000 1.265
+++ kern/vfs_subr.c 16 Dec 2017 23:50:21 -0000
@@ -1583,6 +1583,42 @@ vaccess(enum vtype type, mode_t file_mod
return (file_mode & mask) == mask ? 0 : EACCES;
}
+int vfs_stalling;
+
+int
+vfs_stallmp(struct mount *mp, struct proc *p, int stall)
+{
+ int error;
+
+ if (stall) {
+ error = vfs_busy(mp, VB_WRITE|VB_WAIT);
+ if (error) {
+ printf("%s: busy\n", mp->mnt_stat.f_mntonname);
+ return (error);
+ }
+ uvm_vnp_sync(mp);
+ vfs_stalling = stall;
+ error = VFS_SYNC(mp, MNT_WAIT, p->p_ucred, p);
+ if (error) {
+ printf("%s: failed to sync\n",
mp->mnt_stat.f_mntonname);
+ vfs_unbusy(mp);
+ return (error);
+ }
+ } else {
+ vfs_unbusy(mp);
+ }
+ return (0);
+}
+
+void
+vfs_stall(struct proc *p, int stall)
+{
+ struct mount *mp, *nmp;
+
+ TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, nmp)
+ (void) vfs_stallmp(mp, p, stall);
+}
+
int
vfs_readonly(struct mount *mp, struct proc *p)
{
@@ -1627,10 +1663,8 @@ vfs_rofs(struct proc *p)
{
struct mount *mp, *nmp;
- TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, nmp) {
- /* XXX Here is a race, the next pointer is not locked. */
+ TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, nmp)
(void) vfs_readonly(mp, p);
- }
}
/*
Index: ufs/ffs/ffs_vfsops.c
===================================================================
RCS file: /cvs/src/sys/ufs/ffs/ffs_vfsops.c,v
retrieving revision 1.170
diff -u -p -u -r1.170 ffs_vfsops.c
--- ufs/ffs/ffs_vfsops.c 14 Dec 2017 20:20:38 -0000 1.170
+++ ufs/ffs/ffs_vfsops.c 17 Dec 2017 03:03:06 -0000
@@ -1145,7 +1145,8 @@ struct ffs_sync_args {
};
int
-ffs_sync_vnode(struct vnode *vp, void *arg) {
+ffs_sync_vnode(struct vnode *vp, void *arg)
+{
struct ffs_sync_args *fsa = arg;
struct inode *ip;
int error;
@@ -1193,8 +1194,9 @@ ffs_sync(struct mount *mp, int waitfor,
{
struct ufsmount *ump = VFSTOUFS(mp);
struct fs *fs;
- int error, allerror = 0, count;
+ int error, allerror = 0, count, clean, fmod;
struct ffs_sync_args fsa;
+ extern int vfs_stalling;
fs = ump->um_fs;
/*
@@ -1240,12 +1242,23 @@ ffs_sync(struct mount *mp, int waitfor,
VOP_UNLOCK(ump->um_devvp, p);
}
qsync(mp);
+
/*
* Write back modified superblock.
*/
-
+ clean = fs->fs_clean;
+ fmod = fs->fs_fmod;
+ if (vfs_stalling && (fs->fs_ronly == 0)) {
+ fs->fs_fmod = 1;
+ fs->fs_clean = (fs->fs_flags & FS_UNCLEAN) ? 0 : 1;
+// printf("%s clean %d fmod %d\n",
+// mp->mnt_stat.f_mntonname, fs->fs_clean,
+// fs->fs_fmod);
+ }
if (fs->fs_fmod != 0 && (error = ffs_sbupdate(ump, waitfor)) != 0)
allerror = error;
+ fs->fs_clean = clean;
+ fs->fs_fmod = fmod;
return (allerror);
}
Index: dev/acpi/acpi.c
===================================================================
RCS file: /cvs/src/sys/dev/acpi/acpi.c,v
retrieving revision 1.335
diff -u -p -u -r1.335 acpi.c
--- dev/acpi/acpi.c 29 Nov 2017 22:51:01 -0000 1.335
+++ dev/acpi/acpi.c 17 Dec 2017 00:05:29 -0000
@@ -2439,6 +2439,8 @@ acpi_sleep_state(struct acpi_softc *sc,
{
extern int perflevel;
extern int lid_action;
+ extern void vfs_stall(struct proc *, int);
+ extern int sys_sync(struct proc *, void *, register_t *);
int error = ENXIO;
size_t rndbuflen = 0;
char *rndbuf = NULL;
@@ -2482,6 +2484,7 @@ acpi_sleep_state(struct acpi_softc *sc,
#ifdef HIBERNATE
if (sleepmode == ACPI_SLEEP_HIBERNATE) {
uvmpd_hibernate();
+ // XXX and then vfs_stall + bufq_quiesce?? Bogus!
hibernate_suspend_bufcache();
if (hibernate_alloc()) {
printf("%s: failed to allocate hibernate memory\n",
@@ -2495,6 +2498,7 @@ acpi_sleep_state(struct acpi_softc *sc,
if (config_suspend_all(DVACT_QUIESCE))
goto fail_quiesce;
+ vfs_stall(curproc, 1);
bufq_quiesce();
#ifdef MULTIPROCESSOR
@@ -2507,6 +2511,8 @@ acpi_sleep_state(struct acpi_softc *sc,
disable_intr(); /* PSL_I for resume; PIC/APIC broken until repair */
cold = 2; /* Force other code to delay() instead of tsleep() */
+ vfs_stall(curproc, 0);
+
if (config_suspend_all(DVACT_SUSPEND) != 0)
goto fail_suspend;
acpi_sleep_clocks(sc, state);
@@ -2588,6 +2594,8 @@ fail_alloc:
wsdisplay_resume();
rw_enter_write(&sc->sc_lck);
#endif /* NWSDISPLAY > 0 */
+
+ sys_sync(curproc, NULL, NULL);
/* Restore hw.setperf */
if (cpu_setperf != NULL)
