sys-fs/{spl,zfs} : kernel 4.18 compat

2 files changed, 1394 insertions, 1 deletions

diff --git a/sys-kernel/zfs-dkms/files/kernel-4.18.patch b/sys-kernel/zfs-dkms/files/kernel-4.18.patch
new file mode 100644
index 00000000..ef8d648d
--- /dev/null
+++ b/sys-kernel/zfs-dkms/files/kernel-4.18.patch
@@ -0,0 +1,1393 @@
+From 3cf6af50e0bc02b294bf974a8e653e12c40b5263 Mon Sep 17 00:00:00 2001
+From: Brian Behlendorf <behlendorf1@llnl.gov>
+Date: Sun, 12 Aug 2018 18:22:03 -0400
+Subject: [PATCH] Linux 4.18 compat: inode timespec -> timespec64
+
+Commit torvalds/linux@95582b0 changes the inode i_atime, i_mtime,
+and i_ctime members form timespec's to timespec64's to make them
+2038 safe.  As part of this change the current_time() function was
+also updated to return the timespec64 type.
+
+Resolve this issue by introducing a new inode_timespec_t type which
+is defined to match the timespec type used by the inode.  It should
+be used when working with inode timestamps to ensure matching types.
+
+The timestruc_t type under Illumos was used in a similar fashion but
+was specified to always be a timespec_t.  Rather than incorrectly
+define this type all timespec_t types have been replaced by the new
+inode_timespec_t type.
+
+Finally, the kernel and user space 'sys/time.h' headers were aligned
+with each other.  They define as appropriate for the context several
+constants as macros and include static inline implementation of
+gethrestime(), gethrestime_sec(), and gethrtime().
+
+Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
+Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
+Closes #7643
+Backported-by: Richard Yao <ryao@gentoo.org>
+---
+ config/kernel-current-time.m4 |  7 +++---
+ include/sys/dmu.h             |  2 +-
+ include/sys/dmu_objset.h      |  2 +-
+ include/sys/dsl_dir.h         |  4 ++--
+ include/sys/spa_impl.h        |  2 +-
+ include/sys/xvattr.h          |  2 +-
+ include/sys/zfs_context.h     |  9 +------
+ include/sys/zfs_znode.h       | 33 ++++++++++++++++++-------
+ include/sys/zpl.h             |  9 +++++++
+ lib/libspl/Makefile.am        |  2 --
+ lib/libspl/gethrestime.c      | 38 -----------------------------
+ lib/libspl/gethrtime.c        | 45 -----------------------------------
+ lib/libspl/include/sys/time.h | 37 +++++++++++++++++++++-------
+ lib/libzpool/kernel.c         |  4 ++--
+ module/zfs/dmu_objset.c       |  2 +-
+ module/zfs/dsl_dir.c          |  6 ++---
+ module/zfs/fm.c               |  2 +-
+ module/zfs/zfs_ctldir.c       |  2 +-
+ module/zfs/zfs_vnops.c        |  4 ++--
+ module/zfs/zfs_znode.c        |  4 ++--
+ module/zfs/zpl_inode.c        |  5 ++--
+ 21 files changed, 88 insertions(+), 133 deletions(-)
+ delete mode 100644 lib/libspl/gethrestime.c
+ delete mode 100644 lib/libspl/gethrtime.c
+
+diff --git a/config/kernel-current-time.m4 b/config/kernel-current-time.m4
+index 2ede9ff38c4..c7d5c9b5200 100644
+--- a/config/kernel-current-time.m4
++++ b/config/kernel-current-time.m4
+@@ -1,15 +1,14 @@
+ dnl #
+ dnl # 4.9, current_time() added
++dnl # 4.18, return type changed from timespec to timespec64
+ dnl #
+ AC_DEFUN([ZFS_AC_KERNEL_CURRENT_TIME],
+ 	[AC_MSG_CHECKING([whether current_time() exists])
+ 	ZFS_LINUX_TRY_COMPILE_SYMBOL([
+ 		#include <linux/fs.h>
+ 	], [
+-		struct inode ip;
+-		struct timespec now __attribute__ ((unused));
+-
+-		now = current_time(&ip);
++		struct inode ip __attribute__ ((unused));
++		ip.i_atime = current_time(&ip);
+ 	], [current_time], [fs/inode.c], [
+ 		AC_MSG_RESULT(yes)
+ 		AC_DEFINE(HAVE_CURRENT_TIME, 1, [current_time() exists])
+diff --git a/include/sys/dmu.h b/include/sys/dmu.h
+index bcdf7d646fb..755a90561ae 100644
+--- a/include/sys/dmu.h
++++ b/include/sys/dmu.h
+@@ -891,7 +891,7 @@ uint64_t dmu_objset_fsid_guid(objset_t *os);
+ /*
+  * Get the [cm]time for an objset's snapshot dir
+  */
+-timestruc_t dmu_objset_snap_cmtime(objset_t *os);
++inode_timespec_t dmu_objset_snap_cmtime(objset_t *os);
+ 
+ int dmu_objset_is_snapshot(objset_t *os);
+ 
+diff --git a/include/sys/dmu_objset.h b/include/sys/dmu_objset.h
+index a836e03722c..531e81d4d88 100644
+--- a/include/sys/dmu_objset.h
++++ b/include/sys/dmu_objset.h
+@@ -179,7 +179,7 @@ int dmu_objset_find_dp(struct dsl_pool *dp, uint64_t ddobj,
+     int func(struct dsl_pool *, struct dsl_dataset *, void *),
+     void *arg, int flags);
+ void dmu_objset_evict_dbufs(objset_t *os);
+-timestruc_t dmu_objset_snap_cmtime(objset_t *os);
++inode_timespec_t dmu_objset_snap_cmtime(objset_t *os);
+ 
+ /* called from dsl */
+ void dmu_objset_sync(objset_t *os, zio_t *zio, dmu_tx_t *tx);
+diff --git a/include/sys/dsl_dir.h b/include/sys/dsl_dir.h
+index 69b0b6a5355..80e83fdc4d3 100644
+--- a/include/sys/dsl_dir.h
++++ b/include/sys/dsl_dir.h
+@@ -103,7 +103,7 @@ struct dsl_dir {
+ 	/* Protected by dd_lock */
+ 	kmutex_t dd_lock;
+ 	list_t dd_props; /* list of dsl_prop_record_t's */
+-	timestruc_t dd_snap_cmtime; /* last time snapshot namespace changed */
++	inode_timespec_t dd_snap_cmtime; /* last snapshot namespace change */
+ 	uint64_t dd_origin_txg;
+ 
+ 	/* gross estimate of space used by in-flight tx's */
+@@ -159,7 +159,7 @@ boolean_t dsl_dir_is_clone(dsl_dir_t *dd);
+ void dsl_dir_new_refreservation(dsl_dir_t *dd, struct dsl_dataset *ds,
+     uint64_t reservation, cred_t *cr, dmu_tx_t *tx);
+ void dsl_dir_snap_cmtime_update(dsl_dir_t *dd);
+-timestruc_t dsl_dir_snap_cmtime(dsl_dir_t *dd);
++inode_timespec_t dsl_dir_snap_cmtime(dsl_dir_t *dd);
+ void dsl_dir_set_reservation_sync_impl(dsl_dir_t *dd, uint64_t value,
+     dmu_tx_t *tx);
+ void dsl_dir_zapify(dsl_dir_t *dd, dmu_tx_t *tx);
+diff --git a/include/sys/spa_impl.h b/include/sys/spa_impl.h
+index b1e78c1d592..fa7490ace67 100644
+--- a/include/sys/spa_impl.h
++++ b/include/sys/spa_impl.h
+@@ -153,7 +153,7 @@ struct spa {
+ 	uint64_t	spa_freeze_txg;		/* freeze pool at this txg */
+ 	uint64_t	spa_load_max_txg;	/* best initial ub_txg */
+ 	uint64_t	spa_claim_max_txg;	/* highest claimed birth txg */
+-	timespec_t	spa_loaded_ts;		/* 1st successful open time */
++	inode_timespec_t spa_loaded_ts;		/* 1st successful open time */
+ 	objset_t	*spa_meta_objset;	/* copy of dp->dp_meta_objset */
+ 	kmutex_t	spa_evicting_os_lock;	/* Evicting objset list lock */
+ 	list_t		spa_evicting_os_list;	/* Objsets being evicted. */
+diff --git a/include/sys/xvattr.h b/include/sys/xvattr.h
+index 4779b632163..5d38927cd4b 100644
+--- a/include/sys/xvattr.h
++++ b/include/sys/xvattr.h
+@@ -47,7 +47,7 @@
+  * Structure of all optional attributes.
+  */
+ typedef struct xoptattr {
+-	timestruc_t	xoa_createtime;	/* Create time of file */
++	inode_timespec_t xoa_createtime;	/* Create time of file */
+ 	uint8_t		xoa_archive;
+ 	uint8_t		xoa_system;
+ 	uint8_t		xoa_readonly;
+diff --git a/include/sys/zfs_context.h b/include/sys/zfs_context.h
+index 4fe35342dee..68c58f95531 100644
+--- a/include/sys/zfs_context.h
++++ b/include/sys/zfs_context.h
+@@ -527,7 +527,7 @@ extern char *vn_dumpdir;
+ #define	AV_SCANSTAMP_SZ	32		/* length of anti-virus scanstamp */
+ 
+ typedef struct xoptattr {
+-	timestruc_t	xoa_createtime;	/* Create time of file */
++	inode_timespec_t xoa_createtime;	/* Create time of file */
+ 	uint8_t		xoa_archive;
+ 	uint8_t		xoa_system;
+ 	uint8_t		xoa_readonly;
+@@ -640,13 +640,6 @@ extern void delay(clock_t ticks);
+ #define	USEC_TO_TICK(usec)	((usec) / (MICROSEC / hz))
+ #define	NSEC_TO_TICK(usec)	((usec) / (NANOSEC / hz))
+ 
+-#define	gethrestime_sec() time(NULL)
+-#define	gethrestime(t) \
+-	do {\
+-		(t)->tv_sec = gethrestime_sec();\
+-		(t)->tv_nsec = 0;\
+-	} while (0);
+-
+ #define	max_ncpus	64
+ #define	boot_ncpus	(sysconf(_SC_NPROCESSORS_ONLN))
+ 
+diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
+index c292f03739e..26d1eb37557 100644
+--- a/include/sys/zfs_znode.h
++++ b/include/sys/zfs_znode.h
+@@ -270,19 +270,36 @@ typedef struct znode_hold {
+ 
+ extern unsigned int zfs_object_mutex_size;
+ 
+-/* Encode ZFS stored time values from a struct timespec */
++/*
++ * Encode ZFS stored time values from a struct timespec / struct timespec64.
++ */
+ #define	ZFS_TIME_ENCODE(tp, stmp)		\
+-{						\
++do {						\
+ 	(stmp)[0] = (uint64_t)(tp)->tv_sec;	\
+ 	(stmp)[1] = (uint64_t)(tp)->tv_nsec;	\
+-}
++} while (0)
+ 
+-/* Decode ZFS stored time values to a struct timespec */
++#if defined(HAVE_INODE_TIMESPEC64_TIMES)
++/*
++ * Decode ZFS stored time values to a struct timespec64
++ * 4.18 and newer kernels.
++ */
+ #define	ZFS_TIME_DECODE(tp, stmp)		\
+-{						\
+-	(tp)->tv_sec = (time_t)(stmp)[0];		\
+-	(tp)->tv_nsec = (long)(stmp)[1];		\
+-}
++do {						\
++	(tp)->tv_sec = (time64_t)(stmp)[0];	\
++	(tp)->tv_nsec = (long)(stmp)[1];	\
++} while (0)
++#else
++/*
++ * Decode ZFS stored time values to a struct timespec
++ * 4.17 and older kernels.
++ */
++#define	ZFS_TIME_DECODE(tp, stmp)		\
++do {						\
++	(tp)->tv_sec = (time_t)(stmp)[0];	\
++	(tp)->tv_nsec = (long)(stmp)[1];	\
++} while (0)
++#endif /* HAVE_INODE_TIMESPEC64_TIMES */
+ 
+ /*
+  * Timestamp defines
+diff --git a/include/sys/zpl.h b/include/sys/zpl.h
+index 65ed4313603..e433fbc64ea 100644
+--- a/include/sys/zpl.h
++++ b/include/sys/zpl.h
+@@ -189,4 +189,13 @@ zpl_dir_emit_dots(struct file *file, zpl_dir_context_t *ctx)
+ }
+ #endif /* HAVE_VFS_ITERATE */
+ 
++/*
++ * Linux 4.18, inode times converted from timespec to timespec64.
++ */
++#if defined(HAVE_INODE_TIMESPEC64_TIMES)
++#define	zpl_inode_timespec_trunc(ts, gran)	timespec64_trunc(ts, gran)
++#else
++#define	zpl_inode_timespec_trunc(ts, gran)	timespec_trunc(ts, gran)
++#endif
++
+ #endif	/* _SYS_ZPL_H */
+diff --git a/lib/libspl/Makefile.am b/lib/libspl/Makefile.am
+index 59bc8ffb42f..a6e63cb8868 100644
+--- a/lib/libspl/Makefile.am
++++ b/lib/libspl/Makefile.am
+@@ -19,8 +19,6 @@ noinst_LTLIBRARIES = libspl.la
+ 
+ USER_C = \
+ 	getexecname.c \
+-	gethrtime.c \
+-	gethrestime.c \
+ 	getmntany.c \
+ 	list.c \
+ 	mkdirp.c \
+diff --git a/lib/libspl/gethrestime.c b/lib/libspl/gethrestime.c
+deleted file mode 100644
+index d37cc2d5994..00000000000
+--- a/lib/libspl/gethrestime.c
++++ /dev/null
+@@ -1,38 +0,0 @@
+-/*
+- * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+- * Use is subject to license terms.
+- */
+-
+-#include <time.h>
+-#include <sys/time.h>
+-
+-void
+-gethrestime(timestruc_t *ts)
+-{
+-	struct timeval tv;
+-
+-	gettimeofday(&tv, NULL);
+-	ts->tv_sec = tv.tv_sec;
+-	ts->tv_nsec = tv.tv_usec * NSEC_PER_USEC;
+-}
+diff --git a/lib/libspl/gethrtime.c b/lib/libspl/gethrtime.c
+deleted file mode 100644
+index 95ceb18e119..00000000000
+--- a/lib/libspl/gethrtime.c
++++ /dev/null
+@@ -1,45 +0,0 @@
+-/*
+- * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+- * Use is subject to license terms.
+- */
+-
+-#include <time.h>
+-#include <sys/time.h>
+-#include <stdlib.h>
+-#include <stdio.h>
+-
+-hrtime_t
+-gethrtime(void)
+-{
+-	struct timespec ts;
+-	int rc;
+-
+-	rc = clock_gettime(CLOCK_MONOTONIC, &ts);
+-	if (rc) {
+-		fprintf(stderr, "Error: clock_gettime() = %d\n", rc);
+-		abort();
+-	}
+-
+-	return ((((u_int64_t)ts.tv_sec) * NANOSEC) + ts.tv_nsec);
+-}
+diff --git a/lib/libspl/include/sys/time.h b/lib/libspl/include/sys/time.h
+index dc645fa5c37..04b3ba87bd3 100644
+--- a/lib/libspl/include/sys/time.h
++++ b/lib/libspl/include/sys/time.h
+@@ -27,8 +27,9 @@
+ #ifndef _LIBSPL_SYS_TIME_H
+ #define	_LIBSPL_SYS_TIME_H
+ 
+-#include_next <sys/time.h>
++#include <time.h>
+ #include <sys/types.h>
++#include_next <sys/time.h>
+ 
+ #ifndef SEC
+ #define	SEC		1
+@@ -70,13 +71,33 @@
+ #define	SEC2NSEC(m)	((hrtime_t)(m) * (NANOSEC / SEC))
+ #endif
+ 
+-
+ typedef	long long		hrtime_t;
+-typedef	struct	timespec	timestruc_t;
+-typedef	struct	timespec	timespec_t;
+-
+-
+-extern hrtime_t gethrtime(void);
+-extern void gethrestime(timestruc_t *);
++typedef	struct timespec		timespec_t;
++typedef struct timespec		inode_timespec_t;
++
++static inline void
++gethrestime(inode_timespec_t *ts)
++{
++	struct timeval tv;
++	(void) gettimeofday(&tv, NULL);
++	ts->tv_sec = tv.tv_sec;
++	ts->tv_nsec = tv.tv_usec * NSEC_PER_USEC;
++}
++
++static inline time_t
++gethrestime_sec(void)
++{
++	struct timeval tv;
++	(void) gettimeofday(&tv, NULL);
++	return (tv.tv_sec);
++}
++
++static inline hrtime_t
++gethrtime(void)
++{
++	struct timespec ts;
++	(void) clock_gettime(CLOCK_MONOTONIC, &ts);
++	return ((((u_int64_t)ts.tv_sec) * NANOSEC) + ts.tv_nsec);
++}
+ 
+ #endif /* _LIBSPL_SYS_TIME_H */
+diff --git a/lib/libzpool/kernel.c b/lib/libzpool/kernel.c
+index e67d13c9265..3ea8778b1dc 100644
+--- a/lib/libzpool/kernel.c
++++ b/lib/libzpool/kernel.c
+@@ -498,7 +498,7 @@ cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime)
+ {
+ 	int error;
+ 	struct timeval tv;
+-	timestruc_t ts;
++	struct timespec ts;
+ 	clock_t delta;
+ 
+ 	ASSERT3U(cv->cv_magic, ==, CV_MAGIC);
+@@ -536,7 +536,7 @@ cv_timedwait_hires(kcondvar_t *cv, kmutex_t *mp, hrtime_t tim, hrtime_t res,
+ {
+ 	int error;
+ 	struct timeval tv;
+-	timestruc_t ts;
++	struct timespec ts;
+ 	hrtime_t delta;
+ 
+ 	ASSERT(flag == 0 || flag == CALLOUT_FLAG_ABSOLUTE);
+diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c
+index 3425d542f98..449ebedfa16 100644
+--- a/module/zfs/dmu_objset.c
++++ b/module/zfs/dmu_objset.c
+@@ -860,7 +860,7 @@ dmu_objset_evict_done(objset_t *os)
+ 	kmem_free(os, sizeof (objset_t));
+ }
+ 
+-timestruc_t
++inode_timespec_t
+ dmu_objset_snap_cmtime(objset_t *os)
+ {
+ 	return (dsl_dir_snap_cmtime(os->os_dsl_dataset->ds_dir));
+diff --git a/module/zfs/dsl_dir.c b/module/zfs/dsl_dir.c
+index a3ef5896a3f..deecf6bc53e 100644
+--- a/module/zfs/dsl_dir.c
++++ b/module/zfs/dsl_dir.c
+@@ -1975,10 +1975,10 @@ dsl_dir_transfer_possible(dsl_dir_t *sdd, dsl_dir_t *tdd,
+ 	return (0);
+ }
+ 
+-timestruc_t
++inode_timespec_t
+ dsl_dir_snap_cmtime(dsl_dir_t *dd)
+ {
+-	timestruc_t t;
++	inode_timespec_t t;
+ 
+ 	mutex_enter(&dd->dd_lock);
+ 	t = dd->dd_snap_cmtime;
+@@ -1990,7 +1990,7 @@ dsl_dir_snap_cmtime(dsl_dir_t *dd)
+ void
+ dsl_dir_snap_cmtime_update(dsl_dir_t *dd)
+ {
+-	timestruc_t t;
++	inode_timespec_t t;
+ 
+ 	gethrestime(&t);
+ 	mutex_enter(&dd->dd_lock);
+diff --git a/module/zfs/fm.c b/module/zfs/fm.c
+index cb148149376..9d26cc99eeb 100644
+--- a/module/zfs/fm.c
++++ b/module/zfs/fm.c
+@@ -508,8 +508,8 @@ zfs_zevent_insert(zevent_t *ev)
+ int
+ zfs_zevent_post(nvlist_t *nvl, nvlist_t *detector, zevent_cb_t *cb)
+ {
++	inode_timespec_t tv;
+ 	int64_t tv_array[2];
+-	timestruc_t tv;
+ 	uint64_t eid;
+ 	size_t nvl_size = 0;
+ 	zevent_t *ev;
+diff --git a/module/zfs/zfs_ctldir.c b/module/zfs/zfs_ctldir.c
+index 3b5fb196f1d..3ff2c101b67 100644
+--- a/module/zfs/zfs_ctldir.c
++++ b/module/zfs/zfs_ctldir.c
+@@ -451,7 +451,7 @@ static struct inode *
+ zfsctl_inode_alloc(zfsvfs_t *zfsvfs, uint64_t id,
+     const struct file_operations *fops, const struct inode_operations *ops)
+ {
+-	struct timespec now;
++	inode_timespec_t now;
+ 	struct inode *ip;
+ 	znode_t *zp;
+ 
+diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
+index 0d2b61a1c31..34ea751c320 100644
+--- a/module/zfs/zfs_vnops.c
++++ b/module/zfs/zfs_vnops.c
+@@ -3158,7 +3158,7 @@ zfs_setattr(struct inode *ip, vattr_t *vap, int flags, cred_t *cr)
+ 
+ 	if (mask & (ATTR_MTIME | ATTR_SIZE)) {
+ 		ZFS_TIME_ENCODE(&vap->va_mtime, mtime);
+-		ZTOI(zp)->i_mtime = timespec_trunc(vap->va_mtime,
++		ZTOI(zp)->i_mtime = zpl_inode_timespec_trunc(vap->va_mtime,
+ 		    ZTOI(zp)->i_sb->s_time_gran);
+ 
+ 		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
+@@ -3167,7 +3167,7 @@ zfs_setattr(struct inode *ip, vattr_t *vap, int flags, cred_t *cr)
+ 
+ 	if (mask & (ATTR_CTIME | ATTR_SIZE)) {
+ 		ZFS_TIME_ENCODE(&vap->va_ctime, ctime);
+-		ZTOI(zp)->i_ctime = timespec_trunc(vap->va_ctime,
++		ZTOI(zp)->i_ctime = zpl_inode_timespec_trunc(vap->va_ctime,
+ 		    ZTOI(zp)->i_sb->s_time_gran);
+ 		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
+ 		    ctime, sizeof (ctime));
+diff --git a/module/zfs/zfs_znode.c b/module/zfs/zfs_znode.c
+index f508a248f0f..e222c791183 100644
+--- a/module/zfs/zfs_znode.c
++++ b/module/zfs/zfs_znode.c
+@@ -700,7 +700,7 @@ zfs_mknode(znode_t *dzp, vattr_t *vap, dmu_tx_t *tx, cred_t *cr,
+ 	uint64_t	rdev = 0;
+ 	zfsvfs_t	*zfsvfs = ZTOZSB(dzp);
+ 	dmu_buf_t	*db;
+-	timestruc_t	now;
++	inode_timespec_t now;
+ 	uint64_t	gen, obj;
+ 	int		bonuslen;
+ 	int		dnodesize;
+@@ -1349,7 +1349,7 @@ void
+ zfs_tstamp_update_setup(znode_t *zp, uint_t flag, uint64_t mtime[2],
+     uint64_t ctime[2])
+ {
+-	timestruc_t	now;
++	inode_timespec_t now;
+ 
+ 	gethrestime(&now);
+ 
+diff --git a/module/zfs/zpl_inode.c b/module/zfs/zpl_inode.c
+index 3b5643d0917..41b91cabcb9 100644
+--- a/module/zfs/zpl_inode.c
++++ b/module/zfs/zpl_inode.c
+@@ -384,9 +384,10 @@ zpl_setattr(struct dentry *dentry, struct iattr *ia)
+ 	vap->va_mtime = ia->ia_mtime;
+ 	vap->va_ctime = ia->ia_ctime;
+ 
+-	if (vap->va_mask & ATTR_ATIME)
+-		ip->i_atime = timespec_trunc(ia->ia_atime,
++	if (vap->va_mask & ATTR_ATIME) {
++		ip->i_atime = zpl_inode_timespec_trunc(ia->ia_atime,
+ 		    ip->i_sb->s_time_gran);
++	}
+ 
+ 	cookie = spl_fstrans_mark();
+ 	error = -zfs_setattr(ip, vap, 0, cr);
+From ecaa72315658207608c9e43df870de77af36c1ff Mon Sep 17 00:00:00 2001
+From: Brian Behlendorf <behlendorf1@llnl.gov>
+Date: Fri, 15 Jun 2018 15:05:21 -0700
+Subject: [PATCH] Linux compat 4.18: check_disk_size_change()
+
+Added support for the bops->check_events() interface which was
+added in the 2.6.38 kernel to replace bops->media_changed().
+Fully implementing this functionality allows the volume resize
+code to rely on revalidate_disk(), which is the preferred
+mechanism, and removes the need to use check_disk_size_change().
+
+In order for bops->check_events() to lookup the zvol_state_t
+stored in the disk->private_data the zvol_state_lock needs to
+be held.  Since the check events interface may poll the mutex
+has been converted to a rwlock for better concurrently.  The
+rwlock need only be taken as a writer in the zvol_free() path
+when disk->private_data is set to NULL.
+
+The configure checks for the block_device_operations structure
+were consolidated in a single kernel-block-device-operations.m4
+file.
+
+The ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS configure checks
+and assoicated dead code was removed.  This interface was added
+to the 2.6.28 kernel which predates the oldest supported 2.6.32
+kernel and will therefore always be available.
+
+Updated maximum Linux version in META file.  The 4.17 kernel
+was released on 2018-06-03 and ZoL is compatible with the
+finalized kernel.
+
+Reviewed-by: Boris Protopopov <boris.protopopov@actifio.com>
+Reviewed-by: Sara Hartse <sara.hartse@delphix.com>
+Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
+Closes #7611
+Backported-by: Richard Yao <ryao@gentoo.org>
+---
+ config/kernel-bdev-block-device-operations.m4 |  34 ---
+ ...el-block-device-operations-release-void.m4 |  29 --
+ config/kernel-block-device-operations.m4      |  57 ++++
+ config/kernel.m4                              |   2 +-
+ include/linux/blkdev_compat.h                 |   1 +
+ module/zfs/zvol.c                             | 286 ++++++++----------
+ 6 files changed, 192 insertions(+), 217 deletions(-)
+ delete mode 100644 config/kernel-bdev-block-device-operations.m4
+ delete mode 100644 config/kernel-block-device-operations-release-void.m4
+ create mode 100644 config/kernel-block-device-operations.m4
+
+diff --git a/config/kernel-bdev-block-device-operations.m4 b/config/kernel-bdev-block-device-operations.m4
+deleted file mode 100644
+index faacc195da9..00000000000
+--- a/config/kernel-bdev-block-device-operations.m4
++++ /dev/null
+@@ -1,34 +0,0 @@
+-dnl #
+-dnl # 2.6.x API change
+-dnl #
+-AC_DEFUN([ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS], [
+-	AC_MSG_CHECKING([block device operation prototypes])
+-	tmp_flags="$EXTRA_KCFLAGS"
+-	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
+-	ZFS_LINUX_TRY_COMPILE([
+-		#include <linux/blkdev.h>
+-
+-		int blk_open(struct block_device *bdev, fmode_t mode)
+-		    { return 0; }
+-		int blk_ioctl(struct block_device *bdev, fmode_t mode,
+-		    unsigned x, unsigned long y) { return 0; }
+-		int blk_compat_ioctl(struct block_device * bdev, fmode_t mode,
+-		    unsigned x, unsigned long y) { return 0; }
+-
+-		static const struct block_device_operations
+-		    bops __attribute__ ((unused)) = {
+-			.open		= blk_open,
+-			.release	= NULL,
+-			.ioctl		= blk_ioctl,
+-			.compat_ioctl	= blk_compat_ioctl,
+-		};
+-	],[
+-	],[
+-		AC_MSG_RESULT(struct block_device)
+-		AC_DEFINE(HAVE_BDEV_BLOCK_DEVICE_OPERATIONS, 1,
+-		          [struct block_device_operations use bdevs])
+-	],[
+-		AC_MSG_RESULT(struct inode)
+-	])
+-	EXTRA_KCFLAGS="$tmp_flags"
+-])
+diff --git a/config/kernel-block-device-operations-release-void.m4 b/config/kernel-block-device-operations-release-void.m4
+deleted file mode 100644
+index a73f858722a..00000000000
+--- a/config/kernel-block-device-operations-release-void.m4
++++ /dev/null
+@@ -1,29 +0,0 @@
+-dnl #
+-dnl # 3.10.x API change
+-dnl #
+-AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
+-	AC_MSG_CHECKING([whether block_device_operations.release is void])
+-	tmp_flags="$EXTRA_KCFLAGS"
+-	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
+-	ZFS_LINUX_TRY_COMPILE([
+-		#include <linux/blkdev.h>
+-
+-		void blk_release(struct gendisk *g, fmode_t mode) { return; }
+-
+-		static const struct block_device_operations
+-		    bops __attribute__ ((unused)) = {
+-			.open		= NULL,
+-			.release	= blk_release,
+-			.ioctl		= NULL,
+-			.compat_ioctl	= NULL,
+-		};
+-	],[
+-	],[
+-		AC_MSG_RESULT(void)
+-		AC_DEFINE(HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID, 1,
+-		          [struct block_device_operations.release returns void])
+-	],[
+-		AC_MSG_RESULT(int)
+-	])
+-	EXTRA_KCFLAGS="$tmp_flags"
+-])
+diff --git a/config/kernel-block-device-operations.m4 b/config/kernel-block-device-operations.m4
+new file mode 100644
+index 00000000000..5f2811c1534
+--- /dev/null
++++ b/config/kernel-block-device-operations.m4
+@@ -0,0 +1,57 @@
++dnl #
++dnl # 2.6.38 API change
++dnl #
++AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS], [
++	AC_MSG_CHECKING([whether bops->check_events() exists])
++	tmp_flags="$EXTRA_KCFLAGS"
++	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
++	ZFS_LINUX_TRY_COMPILE([
++		#include <linux/blkdev.h>
++
++		unsigned int blk_check_events(struct gendisk *disk,
++		    unsigned int clearing) { return (0); }
++
++		static const struct block_device_operations
++		    bops __attribute__ ((unused)) = {
++			.check_events	= blk_check_events,
++		};
++	],[
++	],[
++		AC_MSG_RESULT(yes)
++		AC_DEFINE(HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS, 1,
++		    [bops->check_events() exists])
++	],[
++		AC_MSG_RESULT(no)
++	])
++	EXTRA_KCFLAGS="$tmp_flags"
++])
++
++dnl #
++dnl # 3.10.x API change
++dnl #
++AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
++	AC_MSG_CHECKING([whether bops->release() is void])
++	tmp_flags="$EXTRA_KCFLAGS"
++	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
++	ZFS_LINUX_TRY_COMPILE([
++		#include <linux/blkdev.h>
++
++		void blk_release(struct gendisk *g, fmode_t mode) { return; }
++
++		static const struct block_device_operations
++		    bops __attribute__ ((unused)) = {
++			.open		= NULL,
++			.release	= blk_release,
++			.ioctl		= NULL,
++			.compat_ioctl	= NULL,
++		};
++	],[
++	],[
++		AC_MSG_RESULT(void)
++		AC_DEFINE(HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID, 1,
++		          [bops->release() returns void])
++	],[
++		AC_MSG_RESULT(int)
++	])
++	EXTRA_KCFLAGS="$tmp_flags"
++])
+diff --git a/config/kernel.m4 b/config/kernel.m4
+index 375e4b79ae6..c7ca260c5f0 100644
+--- a/config/kernel.m4
++++ b/config/kernel.m4
+@@ -12,7 +12,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
+ 	ZFS_AC_KERNEL_CURRENT_BIO_TAIL
+ 	ZFS_AC_KERNEL_SUPER_USER_NS
+ 	ZFS_AC_KERNEL_SUBMIT_BIO
+-	ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS
++	ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+ 	ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
+ 	ZFS_AC_KERNEL_TYPE_FMODE_T
+ 	ZFS_AC_KERNEL_3ARG_BLKDEV_GET
+diff --git a/include/linux/blkdev_compat.h b/include/linux/blkdev_compat.h
+index f99980ab3e0..27f05662662 100644
+--- a/include/linux/blkdev_compat.h
++++ b/include/linux/blkdev_compat.h
+@@ -32,6 +32,7 @@
+ #include <linux/blkdev.h>
+ #include <linux/elevator.h>
+ #include <linux/backing-dev.h>
++#include <linux/msdos_fs.h>	/* for SECTOR_* */
+ 
+ #ifndef HAVE_FMODE_T
+ typedef unsigned __bitwise__ fmode_t;
+diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
+index 3e7059b340b..e57d2e70332 100644
+--- a/module/zfs/zvol.c
++++ b/module/zfs/zvol.c
+@@ -99,7 +99,7 @@ unsigned long zvol_max_discard_blocks = 16384;
+ unsigned int zvol_volmode = ZFS_VOLMODE_GEOM;
+ 
+ static taskq_t *zvol_taskq;
+-static kmutex_t zvol_state_lock;
++static krwlock_t zvol_state_lock;
+ static list_t zvol_state_list;
+ 
+ #define	ZVOL_HT_SIZE	1024
+@@ -176,17 +176,17 @@ zvol_find_by_dev(dev_t dev)
+ {
+ 	zvol_state_t *zv;
+ 
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_READER);
+ 	for (zv = list_head(&zvol_state_list); zv != NULL;
+ 	    zv = list_next(&zvol_state_list, zv)) {
+ 		mutex_enter(&zv->zv_state_lock);
+ 		if (zv->zv_dev == dev) {
+-			mutex_exit(&zvol_state_lock);
++			rw_exit(&zvol_state_lock);
+ 			return (zv);
+ 		}
+ 		mutex_exit(&zv->zv_state_lock);
+ 	}
+-	mutex_exit(&zvol_state_lock);
++	rw_exit(&zvol_state_lock);
+ 
+ 	return (NULL);
+ }
+@@ -204,7 +204,7 @@ zvol_find_by_name_hash(const char *name, uint64_t hash, int mode)
+ 	zvol_state_t *zv;
+ 	struct hlist_node *p = NULL;
+ 
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_READER);
+ 	hlist_for_each(p, ZVOL_HT_HEAD(hash)) {
+ 		zv = hlist_entry(p, zvol_state_t, zv_hlink);
+ 		mutex_enter(&zv->zv_state_lock);
+@@ -227,12 +227,12 @@ zvol_find_by_name_hash(const char *name, uint64_t hash, int mode)
+ 				    strncmp(zv->zv_name, name, MAXNAMELEN)
+ 				    == 0);
+ 			}
+-			mutex_exit(&zvol_state_lock);
++			rw_exit(&zvol_state_lock);
+ 			return (zv);
+ 		}
+ 		mutex_exit(&zv->zv_state_lock);
+ 	}
+-	mutex_exit(&zvol_state_lock);
++	rw_exit(&zvol_state_lock);
+ 
+ 	return (NULL);
+ }
+@@ -339,24 +339,6 @@ zvol_get_stats(objset_t *os, nvlist_t *nv)
+ 	return (SET_ERROR(error));
+ }
+ 
+-static void
+-zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
+-{
+-	struct block_device *bdev;
+-
+-	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+-
+-	bdev = bdget_disk(zv->zv_disk, 0);
+-	if (bdev == NULL)
+-		return;
+-
+-	set_capacity(zv->zv_disk, volsize >> 9);
+-	zv->zv_volsize = volsize;
+-	check_disk_size_change(zv->zv_disk, bdev);
+-
+-	bdput(bdev);
+-}
+-
+ /*
+  * Sanity check volume size.
+  */
+@@ -409,31 +391,17 @@ zvol_update_volsize(uint64_t volsize, objset_t *os)
+ 	return (error);
+ }
+ 
+-static int
+-zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
+-{
+-	zvol_size_changed(zv, volsize);
+-
+-	/*
+-	 * We should post a event here describing the expansion.  However,
+-	 * the zfs_ereport_post() interface doesn't nicely support posting
+-	 * events for zvols, it assumes events relate to vdevs or zios.
+-	 */
+-
+-	return (0);
+-}
+-
+ /*
+- * Set ZFS_PROP_VOLSIZE set entry point.
++ * Set ZFS_PROP_VOLSIZE set entry point.  Note that modifying the volume
++ * size will result in a udev "change" event being generated.
+  */
+ int
+ zvol_set_volsize(const char *name, uint64_t volsize)
+ {
+-	zvol_state_t *zv = NULL;
+ 	objset_t *os = NULL;
+-	int error;
+-	dmu_object_info_t *doi;
++	struct gendisk *disk = NULL;
+ 	uint64_t readonly;
++	int error;
+ 	boolean_t owned = B_FALSE;
+ 
+ 	error = dsl_prop_get_integer(name,
+@@ -443,7 +411,7 @@ zvol_set_volsize(const char *name, uint64_t volsize)
+ 	if (readonly)
+ 		return (SET_ERROR(EROFS));
+ 
+-	zv = zvol_find_by_name(name, RW_READER);
++	zvol_state_t *zv = zvol_find_by_name(name, RW_READER);
+ 
+ 	ASSERT(zv == NULL || (MUTEX_HELD(&zv->zv_state_lock) &&
+ 	    RW_READ_HELD(&zv->zv_suspend_lock)));
+@@ -464,16 +432,18 @@ zvol_set_volsize(const char *name, uint64_t volsize)
+ 		os = zv->zv_objset;
+ 	}
+ 
+-	doi = kmem_alloc(sizeof (dmu_object_info_t), KM_SLEEP);
++	dmu_object_info_t *doi = kmem_alloc(sizeof (*doi), KM_SLEEP);
+ 
+ 	if ((error = dmu_object_info(os, ZVOL_OBJ, doi)) ||
+ 	    (error = zvol_check_volsize(volsize, doi->doi_data_block_size)))
+ 		goto out;
+ 
+ 	error = zvol_update_volsize(volsize, os);
+-
+-	if (error == 0 && zv != NULL)
+-		error = zvol_update_live_volsize(zv, volsize);
++	if (error == 0 && zv != NULL) {
++		zv->zv_volsize = volsize;
++		zv->zv_changed = 1;
++		disk = zv->zv_disk;
++	}
+ out:
+ 	kmem_free(doi, sizeof (dmu_object_info_t));
+ 
+@@ -488,6 +458,9 @@ zvol_set_volsize(const char *name, uint64_t volsize)
+ 	if (zv != NULL)
+ 		mutex_exit(&zv->zv_state_lock);
+ 
++	if (disk != NULL)
++		revalidate_disk(disk);
++
+ 	return (SET_ERROR(error));
+ }
+ 
+@@ -543,8 +516,8 @@ zvol_set_volblocksize(const char *name, uint64_t volblocksize)
+ 	if (zv == NULL)
+ 		return (SET_ERROR(ENXIO));
+ 
+-	ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
+-	    RW_READ_HELD(&zv->zv_suspend_lock));
++	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
++	ASSERT(RW_READ_HELD(&zv->zv_suspend_lock));
+ 
+ 	if (zv->zv_flags & ZVOL_RDONLY) {
+ 		mutex_exit(&zv->zv_state_lock);
+@@ -1120,7 +1093,7 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
+ static void
+ zvol_insert(zvol_state_t *zv)
+ {
+-	ASSERT(MUTEX_HELD(&zvol_state_lock));
++	ASSERT(RW_WRITE_HELD(&zvol_state_lock));
+ 	ASSERT3U(MINOR(zv->zv_dev) & ZVOL_MINOR_MASK, ==, 0);
+ 	list_insert_head(&zvol_state_list, zv);
+ 	hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash));
+@@ -1132,7 +1105,7 @@ zvol_insert(zvol_state_t *zv)
+ static void
+ zvol_remove(zvol_state_t *zv)
+ {
+-	ASSERT(MUTEX_HELD(&zvol_state_lock));
++	ASSERT(RW_WRITE_HELD(&zvol_state_lock));
+ 	list_remove(&zvol_state_list, zv);
+ 	hlist_del(&zv->zv_hlink);
+ }
+@@ -1148,8 +1121,8 @@ zvol_setup_zv(zvol_state_t *zv)
+ 	uint64_t ro;
+ 	objset_t *os = zv->zv_objset;
+ 
+-	ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
+-	    RW_LOCK_HELD(&zv->zv_suspend_lock));
++	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
++	ASSERT(RW_LOCK_HELD(&zv->zv_suspend_lock));
+ 
+ 	error = dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL);
+ 	if (error)
+@@ -1227,8 +1200,8 @@ zvol_suspend(const char *name)
+ 		return (NULL);
+ 
+ 	/* block all I/O, release in zvol_resume. */
+-	ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
+-	    RW_WRITE_HELD(&zv->zv_suspend_lock));
++	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
++	ASSERT(RW_WRITE_HELD(&zv->zv_suspend_lock));
+ 
+ 	atomic_inc(&zv->zv_suspend_ref);
+ 
+@@ -1349,9 +1322,7 @@ zvol_open(struct block_device *bdev, fmode_t flag)
+ 	int error = 0;
+ 	boolean_t drop_suspend = B_FALSE;
+ 
+-	ASSERT(!mutex_owned(&zvol_state_lock));
+-
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_READER);
+ 	/*
+ 	 * Obtain a copy of private_data under the zvol_state_lock to make
+ 	 * sure that either the result of zvol free code path setting
+@@ -1360,7 +1331,7 @@ zvol_open(struct block_device *bdev, fmode_t flag)
+ 	 */
+ 	zv = bdev->bd_disk->private_data;
+ 	if (zv == NULL) {
+-		mutex_exit(&zvol_state_lock);
++		rw_exit(&zvol_state_lock);
+ 		return (SET_ERROR(-ENXIO));
+ 	}
+ 
+@@ -1378,8 +1349,7 @@ zvol_open(struct block_device *bdev, fmode_t flag)
+ 	} else {
+ 		rw_exit(&zv->zv_suspend_lock);
+ 	}
+-
+-	mutex_exit(&zvol_state_lock);
++	rw_exit(&zvol_state_lock);
+ 
+ 	if (zv->zv_open_count == 0) {
+ 		error = zvol_first_open(zv);
+@@ -1394,11 +1364,18 @@ zvol_open(struct block_device *bdev, fmode_t flag)
+ 
+ 	zv->zv_open_count++;
+ 
++	mutex_exit(&zv->zv_state_lock);
++	if (drop_suspend)
++		rw_exit(&zv->zv_suspend_lock);
++
+ 	check_disk_change(bdev);
+ 
++	return (0);
++
+ out_open_count:
+ 	if (zv->zv_open_count == 0)
+ 		zvol_last_close(zv);
++
+ out_mutex:
+ 	mutex_exit(&zv->zv_state_lock);
+ 	if (drop_suspend)
+@@ -1419,26 +1396,34 @@ zvol_release(struct gendisk *disk, fmode_t mode)
+ 	zvol_state_t *zv;
+ 	boolean_t drop_suspend = B_FALSE;
+ 
+-	ASSERT(!mutex_owned(&zvol_state_lock));
+-
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_READER);
+ 	zv = disk->private_data;
+-	ASSERT(zv && zv->zv_open_count > 0);
+-
+-	/* take zv_suspend_lock before zv_state_lock */
+-	rw_enter(&zv->zv_suspend_lock, RW_READER);
+ 
+ 	mutex_enter(&zv->zv_state_lock);
+-	mutex_exit(&zvol_state_lock);
++	ASSERT(zv && zv->zv_open_count > 0);
+ 
+ 	/*
+ 	 * make sure zvol is not suspended during last close
+ 	 * (hold zv_suspend_lock), otherwise, drop the lock
+ 	 */
+-	if (zv->zv_open_count == 1)
+-		drop_suspend = B_TRUE;
+-	else
+-		rw_exit(&zv->zv_suspend_lock);
++	if (zv->zv_open_count == 1) {
++		if (!rw_tryenter(&zv->zv_suspend_lock, RW_READER)) {
++			mutex_exit(&zv->zv_state_lock);
++			rw_enter(&zv->zv_suspend_lock, RW_READER);
++			mutex_enter(&zv->zv_state_lock);
++			/* check to see if zv_suspend_lock is needed */
++			if (zv->zv_open_count != 1) {
++				rw_exit(&zv->zv_suspend_lock);
++				drop_suspend = B_FALSE;
++			}
++		}
++	} else {
++		drop_suspend = B_FALSE;
++	}
++	rw_exit(&zvol_state_lock);
++
++	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
++	ASSERT(zv->zv_open_count != 1 || RW_READ_HELD(&zv->zv_suspend_lock));
+ 
+ 	zv->zv_open_count--;
+ 	if (zv->zv_open_count == 0)
+@@ -1461,7 +1446,7 @@ zvol_ioctl(struct block_device *bdev, fmode_t mode,
+ 	zvol_state_t *zv = bdev->bd_disk->private_data;
+ 	int error = 0;
+ 
+-	ASSERT(zv && zv->zv_open_count > 0);
++	ASSERT3U(zv->zv_open_count, >, 0);
+ 
+ 	switch (cmd) {
+ 	case BLKFLSBUF:
+@@ -1501,23 +1486,62 @@ zvol_compat_ioctl(struct block_device *bdev, fmode_t mode,
+ #define	zvol_compat_ioctl	NULL
+ #endif
+ 
++/*
++ * Linux 2.6.38 preferred interface.
++ */
++#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
++static unsigned int
++zvol_check_events(struct gendisk *disk, unsigned int clearing)
++{
++	unsigned int mask = 0;
++
++	rw_enter(&zvol_state_lock, RW_READER);
++
++	zvol_state_t *zv = disk->private_data;
++	if (zv != NULL) {
++		mutex_enter(&zv->zv_state_lock);
++		mask = zv->zv_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
++		zv->zv_changed = 0;
++		mutex_exit(&zv->zv_state_lock);
++	}
++
++	rw_exit(&zvol_state_lock);
++
++	return (mask);
++}
++#else
+ static int zvol_media_changed(struct gendisk *disk)
+ {
++	int changed = 0;
++
++	rw_enter(&zvol_state_lock, RW_READER);
++
+ 	zvol_state_t *zv = disk->private_data;
++	if (zv != NULL) {
++		mutex_enter(&zv->zv_state_lock);
++		changed = zv->zv_changed;
++		zv->zv_changed = 0;
++		mutex_exit(&zv->zv_state_lock);
++	}
+ 
+-	ASSERT(zv && zv->zv_open_count > 0);
++	rw_exit(&zvol_state_lock);
+ 
+-	return (zv->zv_changed);
++	return (changed);
+ }
++#endif
+ 
+ static int zvol_revalidate_disk(struct gendisk *disk)
+ {
+-	zvol_state_t *zv = disk->private_data;
++	rw_enter(&zvol_state_lock, RW_READER);
+ 
+-	ASSERT(zv && zv->zv_open_count > 0);
++	zvol_state_t *zv = disk->private_data;
++	if (zv != NULL) {
++		mutex_enter(&zv->zv_state_lock);
++		set_capacity(zv->zv_disk, zv->zv_volsize >> SECTOR_BITS);
++		mutex_exit(&zv->zv_state_lock);
++	}
+ 
+-	zv->zv_changed = 0;
+-	set_capacity(zv->zv_disk, zv->zv_volsize >> 9);
++	rw_exit(&zvol_state_lock);
+ 
+ 	return (0);
+ }
+@@ -1534,7 +1558,7 @@ zvol_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+ 	zvol_state_t *zv = bdev->bd_disk->private_data;
+ 	sector_t sectors;
+ 
+-	ASSERT(zv && zv->zv_open_count > 0);
++	ASSERT3U(zv->zv_open_count, >, 0);
+ 
+ 	sectors = get_capacity(zv->zv_disk);
+ 
+@@ -1567,68 +1591,20 @@ zvol_probe(dev_t dev, int *part, void *arg)
+ 	return (kobj);
+ }
+ 
+-#ifdef HAVE_BDEV_BLOCK_DEVICE_OPERATIONS
+ static struct block_device_operations zvol_ops = {
+ 	.open			= zvol_open,
+ 	.release		= zvol_release,
+ 	.ioctl			= zvol_ioctl,
+ 	.compat_ioctl		= zvol_compat_ioctl,
+-	.media_changed		= zvol_media_changed,
+-	.revalidate_disk	= zvol_revalidate_disk,
+-	.getgeo			= zvol_getgeo,
+-	.owner			= THIS_MODULE,
+-};
+-
+-#else /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
+-
+-static int
+-zvol_open_by_inode(struct inode *inode, struct file *file)
+-{
+-	return (zvol_open(inode->i_bdev, file->f_mode));
+-}
+-
+-static int
+-zvol_release_by_inode(struct inode *inode, struct file *file)
+-{
+-	return (zvol_release(inode->i_bdev->bd_disk, file->f_mode));
+-}
+-
+-static int
+-zvol_ioctl_by_inode(struct inode *inode, struct file *file,
+-    unsigned int cmd, unsigned long arg)
+-{
+-	if (file == NULL || inode == NULL)
+-		return (SET_ERROR(-EINVAL));
+-
+-	return (zvol_ioctl(inode->i_bdev, file->f_mode, cmd, arg));
+-}
+-
+-#ifdef CONFIG_COMPAT
+-static long
+-zvol_compat_ioctl_by_inode(struct file *file,
+-    unsigned int cmd, unsigned long arg)
+-{
+-	if (file == NULL)
+-		return (SET_ERROR(-EINVAL));
+-
+-	return (zvol_compat_ioctl(file->f_dentry->d_inode->i_bdev,
+-	    file->f_mode, cmd, arg));
+-}
++#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
++	.check_events		= zvol_check_events,
+ #else
+-#define	zvol_compat_ioctl_by_inode	NULL
+-#endif
+-
+-static struct block_device_operations zvol_ops = {
+-	.open			= zvol_open_by_inode,
+-	.release		= zvol_release_by_inode,
+-	.ioctl			= zvol_ioctl_by_inode,
+-	.compat_ioctl		= zvol_compat_ioctl_by_inode,
+ 	.media_changed		= zvol_media_changed,
++#endif
+ 	.revalidate_disk	= zvol_revalidate_disk,
+ 	.getgeo			= zvol_getgeo,
+ 	.owner			= THIS_MODULE,
+ };
+-#endif /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
+ 
+ /*
+  * Allocate memory for a new zvol_state_t and setup the required
+@@ -1681,6 +1657,10 @@ zvol_alloc(dev_t dev, const char *name)
+ 	rw_init(&zv->zv_suspend_lock, NULL, RW_DEFAULT, NULL);
+ 
+ 	zv->zv_disk->major = zvol_major;
++#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
++	zv->zv_disk->events = DISK_EVENT_MEDIA_CHANGE;
++#endif
++
+ 	if (volmode == ZFS_VOLMODE_DEV) {
+ 		/*
+ 		 * ZFS_VOLMODE_DEV disable partitioning on ZVOL devices: set
+@@ -1725,7 +1705,6 @@ zvol_free(void *arg)
+ {
+ 	zvol_state_t *zv = arg;
+ 
+-	ASSERT(!MUTEX_HELD(&zvol_state_lock));
+ 	ASSERT(!RW_LOCK_HELD(&zv->zv_suspend_lock));
+ 	ASSERT(!MUTEX_HELD(&zv->zv_state_lock));
+ 	ASSERT(zv->zv_open_count == 0);
+@@ -1852,9 +1831,9 @@ zvol_create_minor_impl(const char *name)
+ 	kmem_free(doi, sizeof (dmu_object_info_t));
+ 
+ 	if (error == 0) {
+-		mutex_enter(&zvol_state_lock);
++		rw_enter(&zvol_state_lock, RW_WRITER);
+ 		zvol_insert(zv);
+-		mutex_exit(&zvol_state_lock);
++		rw_exit(&zvol_state_lock);
+ 		add_disk(zv->zv_disk);
+ 	} else {
+ 		ida_simple_remove(&zvol_ida, idx);
+@@ -1871,7 +1850,7 @@ zvol_rename_minor(zvol_state_t *zv, const char *newname)
+ {
+ 	int readonly = get_disk_ro(zv->zv_disk);
+ 
+-	ASSERT(MUTEX_HELD(&zvol_state_lock));
++	ASSERT(RW_LOCK_HELD(&zvol_state_lock));
+ 	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+ 
+ 	strlcpy(zv->zv_name, newname, sizeof (zv->zv_name));
+@@ -2111,7 +2090,7 @@ zvol_remove_minors_impl(const char *name)
+ 	list_create(&free_list, sizeof (zvol_state_t),
+ 	    offsetof(zvol_state_t, zv_next));
+ 
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_WRITER);
+ 
+ 	for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) {
+ 		zv_next = list_next(&zvol_state_list, zv);
+@@ -2136,15 +2115,15 @@ zvol_remove_minors_impl(const char *name)
+ 			zvol_remove(zv);
+ 
+ 			/*
+-			 * clear this while holding zvol_state_lock so
+-			 * zvol_open won't open it
++			 * Cleared while holding zvol_state_lock as a writer
++			 * which will prevent zvol_open() from opening it.
+ 			 */
+ 			zv->zv_disk->private_data = NULL;
+ 
+ 			/* Drop zv_state_lock before zvol_free() */
+ 			mutex_exit(&zv->zv_state_lock);
+ 
+-			/* try parallel zv_free, if failed do it in place */
++			/* Try parallel zv_free, if failed do it in place */
+ 			t = taskq_dispatch(system_taskq, zvol_free, zv,
+ 			    TQ_SLEEP);
+ 			if (t == TASKQID_INVALID)
+@@ -2155,11 +2134,9 @@ zvol_remove_minors_impl(const char *name)
+ 			mutex_exit(&zv->zv_state_lock);
+ 		}
+ 	}
+-	mutex_exit(&zvol_state_lock);
++	rw_exit(&zvol_state_lock);
+ 
+-	/*
+-	 * Drop zvol_state_lock before calling zvol_free()
+-	 */
++	/* Drop zvol_state_lock before calling zvol_free() */
+ 	while ((zv = list_head(&free_list)) != NULL) {
+ 		list_remove(&free_list, zv);
+ 		zvol_free(zv);
+@@ -2178,7 +2155,7 @@ zvol_remove_minor_impl(const char *name)
+ 	if (zvol_inhibit_dev)
+ 		return;
+ 
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_WRITER);
+ 
+ 	for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) {
+ 		zv_next = list_next(&zvol_state_list, zv);
+@@ -2198,7 +2175,10 @@ zvol_remove_minor_impl(const char *name)
+ 			}
+ 			zvol_remove(zv);
+ 
+-			/* clear this so zvol_open won't open it */
++			/*
++			 * Cleared while holding zvol_state_lock as a writer
++			 * which will prevent zvol_open() from opening it.
++			 */
+ 			zv->zv_disk->private_data = NULL;
+ 
+ 			mutex_exit(&zv->zv_state_lock);
+@@ -2209,7 +2189,7 @@ zvol_remove_minor_impl(const char *name)
+ 	}
+ 
+ 	/* Drop zvol_state_lock before calling zvol_free() */
+-	mutex_exit(&zvol_state_lock);
++	rw_exit(&zvol_state_lock);
+ 
+ 	if (zv != NULL)
+ 		zvol_free(zv);
+@@ -2230,7 +2210,7 @@ zvol_rename_minors_impl(const char *oldname, const char *newname)
+ 	oldnamelen = strlen(oldname);
+ 	newnamelen = strlen(newname);
+ 
+-	mutex_enter(&zvol_state_lock);
++	rw_enter(&zvol_state_lock, RW_READER);
+ 
+ 	for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) {
+ 		zv_next = list_next(&zvol_state_list, zv);
+@@ -2258,7 +2238,7 @@ zvol_rename_minors_impl(const char *oldname, const char *newname)
+ 		mutex_exit(&zv->zv_state_lock);
+ 	}
+ 
+-	mutex_exit(&zvol_state_lock);
++	rw_exit(&zvol_state_lock);
+ }
+ 
+ typedef struct zvol_snapdev_cb_arg {
+@@ -2635,7 +2615,7 @@ zvol_init(void)
+ 
+ 	list_create(&zvol_state_list, sizeof (zvol_state_t),
+ 	    offsetof(zvol_state_t, zv_next));
+-	mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL);
++	rw_init(&zvol_state_lock, NULL, RW_DEFAULT, NULL);
+ 	ida_init(&zvol_ida);
+ 
+ 	zvol_taskq = taskq_create(ZVOL_DRIVER, threads, maxclsyspri,
+@@ -2672,7 +2652,7 @@ zvol_init(void)
+ 	taskq_destroy(zvol_taskq);
+ out:
+ 	ida_destroy(&zvol_ida);
+-	mutex_destroy(&zvol_state_lock);
++	rw_destroy(&zvol_state_lock);
+ 	list_destroy(&zvol_state_list);
+ 
+ 	return (SET_ERROR(error));
+@@ -2689,7 +2669,7 @@ zvol_fini(void)
+ 
+ 	taskq_destroy(zvol_taskq);
+ 	list_destroy(&zvol_state_list);
+-	mutex_destroy(&zvol_state_lock);
++	rw_destroy(&zvol_state_lock);
+ 
+ 	ida_destroy(&zvol_ida);
+ }
diff --git a/sys-kernel/zfs-dkms/zfs-dkms-0.7.9.ebuild b/sys-kernel/zfs-dkms/zfs-dkms-0.7.9-r1.ebuild
index fdfb5728..3f5b98be 100644
--- a/sys-kernel/zfs-dkms/zfs-dkms-0.7.9.ebuild
+++ b/sys-kernel/zfs-dkms/zfs-dkms-0.7.9-r1.ebuild
@@ -23,7 +23,7 @@ RDEPEND="${DEPEND}"
 S="${WORKDIR}/${MY_P}"
 
 src_prepare() {
-	:
+	epatch "${FILESDIR}/kernel-4.18.patch"
 }
 
 src_configure() {