Date: Mon, 8 Dec 2014 16:48:58 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r275620 - in head/sys: kern sys Message-ID: <201412081648.sB8GmwCB019038@svn.freebsd.org>
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Author: kib Date: Mon Dec 8 16:48:57 2014 New Revision: 275620 URL: https://svnweb.freebsd.org/changeset/base/275620 Log: Add functions syncer_suspend() and syncer_resume(), which are supposed to be called before suspension and after resume, correspondingly. The syncer_suspend() ensures that all filesystems dirty data and metadata are saved to the permanent storage, and stops kernel threads which might modify filesystems. The syncer_resume() restores stopped threads. For now, only syncer is stopped. This is needed, because each sync loop causes superblock updates for UFS. Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/kern/vfs_subr.c head/sys/sys/mount.h Modified: head/sys/kern/vfs_subr.c ============================================================================== --- head/sys/kern/vfs_subr.c Mon Dec 8 16:42:34 2014 (r275619) +++ head/sys/kern/vfs_subr.c Mon Dec 8 16:48:57 2014 (r275620) @@ -1773,6 +1773,8 @@ sync_vnode(struct synclist *slp, struct return (0); } +static int first_printf = 1; + /* * System filesystem synchronizer daemon. */ @@ -1791,7 +1793,6 @@ sched_sync(void) last_work_seen = 0; syncer_final_iter = 0; - first_printf = 1; syncer_state = SYNCER_RUNNING; starttime = time_uptime; td->td_pflags |= TDP_NORUNNINGBUF; @@ -1955,6 +1956,25 @@ syncer_shutdown(void *arg, int howto) kproc_shutdown(arg, howto); } +void +syncer_suspend(void) +{ + + syncer_shutdown(updateproc, 0); +} + +void +syncer_resume(void) +{ + + mtx_lock(&sync_mtx); + first_printf = 1; + syncer_state = SYNCER_RUNNING; + mtx_unlock(&sync_mtx); + cv_broadcast(&sync_wakeup); + kproc_resume(updateproc); +} + /* * Reassign a buffer from one vnode to another. * Used to assign file specific control information Modified: head/sys/sys/mount.h ============================================================================== --- head/sys/sys/mount.h Mon Dec 8 16:42:34 2014 (r275619) +++ head/sys/sys/mount.h Mon Dec 8 16:48:57 2014 (r275620) @@ -917,6 +917,9 @@ vfs_uninit_t vfs_stduninit; vfs_extattrctl_t vfs_stdextattrctl; vfs_sysctl_t vfs_stdsysctl; +void syncer_suspend(void); +void syncer_resume(void); + #else /* !_KERNEL */ #include <sys/cdefs.h>
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