Merge branch 'bugfixes' into nfs-for-next

arch/arm/include/asm/io.h

@@ -64,7 +64,7 @@ extern void __raw_readsl(const void __iomem *addr, void *data, int longlen);
 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
 {
 	asm volatile("strh %1, %0"
-		     : "+Qo" (*(volatile u16 __force *)addr)
+		     : "+Q" (*(volatile u16 __force *)addr)
 		     : "r" (val));
 }
 
@@ -72,7 +72,7 @@ static inline u16 __raw_readw(const volatile void __iomem *addr)
 {
 	u16 val;
 	asm volatile("ldrh %1, %0"
-		     : "+Qo" (*(volatile u16 __force *)addr),
+		     : "+Q" (*(volatile u16 __force *)addr),
 		       "=r" (val));
 	return val;
 }

arch/arm/include/asm/sched_clock.h

@@ -10,7 +10,5 @@
 
 extern void sched_clock_postinit(void);
 extern void setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate);
-extern void setup_sched_clock_needs_suspend(u32 (*read)(void), int bits,
-		unsigned long rate);
 
 #endif

arch/arm/include/asm/vfpmacros.h

@@ -27,9 +27,9 @@
 #if __LINUX_ARM_ARCH__ <= 6
 	ldr	\tmp, =elf_hwcap		    @ may not have MVFR regs
 	ldr	\tmp, [\tmp, #0]
-	tst	\tmp, #HWCAP_VFPv3D16
-	ldceql	p11, cr0, [\base],#32*4		    @ FLDMIAD \base!, {d16-d31}
-	addne	\base, \base, #32*4		    @ step over unused register space
+	tst	\tmp, #HWCAP_VFPD32
+	ldcnel	p11, cr0, [\base],#32*4		    @ FLDMIAD \base!, {d16-d31}
+	addeq	\base, \base, #32*4		    @ step over unused register space
 #else
 	VFPFMRX	\tmp, MVFR0			    @ Media and VFP Feature Register 0
 	and	\tmp, \tmp, #MVFR0_A_SIMD_MASK	    @ A_SIMD field
@@ -51,9 +51,9 @@
 #if __LINUX_ARM_ARCH__ <= 6
 	ldr	\tmp, =elf_hwcap		    @ may not have MVFR regs
 	ldr	\tmp, [\tmp, #0]
-	tst	\tmp, #HWCAP_VFPv3D16
-	stceql	p11, cr0, [\base],#32*4		    @ FSTMIAD \base!, {d16-d31}
-	addne	\base, \base, #32*4		    @ step over unused register space
+	tst	\tmp, #HWCAP_VFPD32
+	stcnel	p11, cr0, [\base],#32*4		    @ FSTMIAD \base!, {d16-d31}
+	addeq	\base, \base, #32*4		    @ step over unused register space
 #else
 	VFPFMRX	\tmp, MVFR0			    @ Media and VFP Feature Register 0
 	and	\tmp, \tmp, #MVFR0_A_SIMD_MASK	    @ A_SIMD field

arch/arm/include/uapi/asm/hwcap.h

@@ -18,11 +18,12 @@
 #define HWCAP_THUMBEE	(1 << 11)
 #define HWCAP_NEON	(1 << 12)
 #define HWCAP_VFPv3	(1 << 13)
-#define HWCAP_VFPv3D16	(1 << 14)
+#define HWCAP_VFPv3D16	(1 << 14)	/* also set for VFPv4-D16 */
 #define HWCAP_TLS	(1 << 15)
 #define HWCAP_VFPv4	(1 << 16)
 #define HWCAP_IDIVA	(1 << 17)
 #define HWCAP_IDIVT	(1 << 18)
+#define HWCAP_VFPD32	(1 << 19)	/* set if VFP has 32 regs (not 16) */
 #define HWCAP_IDIV	(HWCAP_IDIVA | HWCAP_IDIVT)
 
 

arch/arm/kernel/sched_clock.c

@@ -107,13 +107,6 @@ static void sched_clock_poll(unsigned long wrap_ticks)
 	update_sched_clock();
 }
 
-void __init setup_sched_clock_needs_suspend(u32 (*read)(void), int bits,
-		unsigned long rate)
-{
-	setup_sched_clock(read, bits, rate);
-	cd.needs_suspend = true;
-}
-
 void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
 {
 	unsigned long r, w;
@@ -189,18 +182,15 @@ void __init sched_clock_postinit(void)
 static int sched_clock_suspend(void)
 {
 	sched_clock_poll(sched_clock_timer.data);
-	if (cd.needs_suspend)
 	cd.suspended = true;
 	return 0;
 }
 
 static void sched_clock_resume(void)
 {
-	if (cd.needs_suspend) {
 	cd.epoch_cyc = read_sched_clock();
 	cd.epoch_cyc_copy = cd.epoch_cyc;
 	cd.suspended = false;
-	}
 }
 
 static struct syscore_ops sched_clock_ops = {

arch/arm/mm/alignment.c

@@ -745,7 +745,7 @@ do_alignment_t32_to_handler(unsigned long *pinstr, struct pt_regs *regs,
 static int
 do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
-	union offset_union offset;
+	union offset_union uninitialized_var(offset);
 	unsigned long instr = 0, instrptr;
 	int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs);
 	unsigned int type;

arch/arm/vfp/vfpmodule.c

@@ -701,11 +701,14 @@ static int __init vfp_init(void)
 			elf_hwcap |= HWCAP_VFPv3;
 
 			/*
-			 * Check for VFPv3 D16. CPUs in this configuration
-			 * only have 16 x 64bit registers.
+			 * Check for VFPv3 D16 and VFPv4 D16.  CPUs in
+			 * this configuration only have 16 x 64bit
+			 * registers.
 			 */
 			if (((fmrx(MVFR0) & MVFR0_A_SIMD_MASK)) == 1)
-				elf_hwcap |= HWCAP_VFPv3D16;
+				elf_hwcap |= HWCAP_VFPv3D16; /* also v4-D16 */
+			else
+				elf_hwcap |= HWCAP_VFPD32;
 		}
 #endif
 		/*

drivers/gpu/drm/drm_fops.c

@@ -121,6 +121,8 @@ int drm_open(struct inode *inode, struct file *filp)
 	int minor_id = iminor(inode);
 	struct drm_minor *minor;
 	int retcode = 0;
+	int need_setup = 0;
+	struct address_space *old_mapping;
 
 	minor = idr_find(&drm_minors_idr, minor_id);
 	if (!minor)
@@ -132,23 +134,37 @@ int drm_open(struct inode *inode, struct file *filp)
 	if (drm_device_is_unplugged(dev))
 		return -ENODEV;
 
-	retcode = drm_open_helper(inode, filp, dev);
-	if (!retcode) {
-		atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 	if (!dev->open_count++)
-			retcode = drm_setup(dev);
-	}
-	if (!retcode) {
+		need_setup = 1;
 	mutex_lock(&dev->struct_mutex);
-		if (dev->dev_mapping == NULL)
+	old_mapping = dev->dev_mapping;
+	if (old_mapping == NULL)
 		dev->dev_mapping = &inode->i_data;
 	/* ihold ensures nobody can remove inode with our i_data */
 	ihold(container_of(dev->dev_mapping, struct inode, i_data));
 	inode->i_mapping = dev->dev_mapping;
 	filp->f_mapping = dev->dev_mapping;
 	mutex_unlock(&dev->struct_mutex);
+
+	retcode = drm_open_helper(inode, filp, dev);
+	if (retcode)
+		goto err_undo;
+	atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
+	if (need_setup) {
+		retcode = drm_setup(dev);
+		if (retcode)
+			goto err_undo;
 	}
+	return 0;
 
+err_undo:
+	mutex_lock(&dev->struct_mutex);
+	filp->f_mapping = old_mapping;
+	inode->i_mapping = old_mapping;
+	iput(container_of(dev->dev_mapping, struct inode, i_data));
+	dev->dev_mapping = old_mapping;
+	mutex_unlock(&dev->struct_mutex);
+	dev->open_count--;
 	return retcode;
 }
 EXPORT_SYMBOL(drm_open);

drivers/gpu/drm/radeon/evergreen.c

@@ -1372,7 +1372,7 @@ void evergreen_mc_resume(struct radeon_device *rdev, struct evergreen_mc_save *s
 	WREG32(BIF_FB_EN, FB_READ_EN | FB_WRITE_EN);
 
 	for (i = 0; i < rdev->num_crtc; i++) {
-		if (save->crtc_enabled) {
+		if (save->crtc_enabled[i]) {
 			if (ASIC_IS_DCE6(rdev)) {
 				tmp = RREG32(EVERGREEN_CRTC_BLANK_CONTROL + crtc_offsets[i]);
 				tmp |= EVERGREEN_CRTC_BLANK_DATA_EN;

drivers/hwmon/w83627ehf.c

@@ -2083,6 +2083,7 @@ static int __devinit w83627ehf_probe(struct platform_device *pdev)
 	mutex_init(&data->lock);
 	mutex_init(&data->update_lock);
 	data->name = w83627ehf_device_names[sio_data->kind];
+	data->bank = 0xff;		/* Force initial bank selection */
 	platform_set_drvdata(pdev, data);
 
 	/* 627EHG and 627EHF have 10 voltage inputs; 627DHG and 667HG have 9 */

fs/gfs2/file.c

@@ -516,15 +516,13 @@ static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 		struct gfs2_holder i_gh;
 		int error;
 
-		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
-		error = gfs2_glock_nq(&i_gh);
-		if (error == 0) {
-			file_accessed(file);
-			gfs2_glock_dq(&i_gh);
-		}
-		gfs2_holder_uninit(&i_gh);
+		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
+					   &i_gh);
 		if (error)
 			return error;
+		/* grab lock to update inode */
+		gfs2_glock_dq_uninit(&i_gh);
+		file_accessed(file);
 	}
 	vma->vm_ops = &gfs2_vm_ops;
 
@@ -677,10 +675,8 @@ static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	size_t writesize = iov_length(iov, nr_segs);
 	struct dentry *dentry = file->f_dentry;
 	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
-	struct gfs2_sbd *sdp;
 	int ret;
 
-	sdp = GFS2_SB(file->f_mapping->host);
 	ret = gfs2_rs_alloc(ip);
 	if (ret)
 		return ret;

fs/gfs2/lops.c

@@ -393,12 +393,10 @@ static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	struct gfs2_meta_header *mh;
 	struct gfs2_trans *tr;
 
-	lock_buffer(bd->bd_bh);
-	gfs2_log_lock(sdp);
 	tr = current->journal_info;
 	tr->tr_touched = 1;
 	if (!list_empty(&bd->bd_list))
-		goto out;
+		return;
 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
 	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
@@ -414,9 +412,6 @@ static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	sdp->sd_log_num_buf++;
 	list_add(&bd->bd_list, &sdp->sd_log_le_buf);
 	tr->tr_num_buf_new++;
-out:
-	gfs2_log_unlock(sdp);
-	unlock_buffer(bd->bd_bh);
 }
 
 static void gfs2_check_magic(struct buffer_head *bh)
@@ -621,7 +616,6 @@ static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 
 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
 {
-	struct gfs2_log_descriptor *ld;
 	struct gfs2_meta_header *mh;
 	unsigned int offset;
 	struct list_head *head = &sdp->sd_log_le_revoke;
@@ -634,7 +628,6 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
 
 	length = gfs2_struct2blk(sdp, sdp->sd_log_num_revoke, sizeof(u64));
 	page = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE, length, sdp->sd_log_num_revoke);
-	ld = page_address(page);
 	offset = sizeof(struct gfs2_log_descriptor);
 
 	list_for_each_entry(bd, head, bd_list) {
@@ -777,12 +770,10 @@ static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	struct address_space *mapping = bd->bd_bh->b_page->mapping;
 	struct gfs2_inode *ip = GFS2_I(mapping->host);
 
-	lock_buffer(bd->bd_bh);
-	gfs2_log_lock(sdp);
 	if (tr)
 		tr->tr_touched = 1;
 	if (!list_empty(&bd->bd_list))
-		goto out;
+		return;
 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
 	if (gfs2_is_jdata(ip)) {
@@ -793,9 +784,6 @@ static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	} else {
 		list_add_tail(&bd->bd_list, &sdp->sd_log_le_ordered);
 	}
-out:
-	gfs2_log_unlock(sdp);
-	unlock_buffer(bd->bd_bh);
 }
 
 /**

fs/gfs2/quota.c

@@ -497,8 +497,11 @@ int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
 	struct gfs2_quota_data **qd;
 	int error;
 
-	if (ip->i_res == NULL)
-		gfs2_rs_alloc(ip);
+	if (ip->i_res == NULL) {
+		error = gfs2_rs_alloc(ip);
+		if (error)
+			return error;
+	}
 
 	qd = ip->i_res->rs_qa_qd;
 

fs/gfs2/rgrp.c

@@ -553,7 +553,6 @@ void gfs2_free_clones(struct gfs2_rgrpd *rgd)
  */
 int gfs2_rs_alloc(struct gfs2_inode *ip)
 {
-	int error = 0;
 	struct gfs2_blkreserv *res;
 
 	if (ip->i_res)
@@ -561,7 +560,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
 
 	res = kmem_cache_zalloc(gfs2_rsrv_cachep, GFP_NOFS);
 	if (!res)
-		error = -ENOMEM;
+		return -ENOMEM;
 
 	RB_CLEAR_NODE(&res->rs_node);
 
@@ -571,7 +570,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
 	else
 		ip->i_res = res;
 	up_write(&ip->i_rw_mutex);
-	return error;
+	return 0;
 }
 
 static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs)
@@ -1263,7 +1262,9 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 	int ret = 0;
 	u64 amt;
 	u64 trimmed = 0;
+	u64 start, end, minlen;
 	unsigned int x;
+	unsigned bs_shift = sdp->sd_sb.sb_bsize_shift;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -1271,19 +1272,25 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
-	if (argp == NULL) {
-		r.start = 0;
-		r.len = ULLONG_MAX;
-		r.minlen = 0;
-	} else if (copy_from_user(&r, argp, sizeof(r)))
+	if (copy_from_user(&r, argp, sizeof(r)))
 		return -EFAULT;
 
 	ret = gfs2_rindex_update(sdp);
 	if (ret)
 		return ret;
 
-	rgd = gfs2_blk2rgrpd(sdp, r.start, 0);
-	rgd_end = gfs2_blk2rgrpd(sdp, r.start + r.len, 0);
+	start = r.start >> bs_shift;
+	end = start + (r.len >> bs_shift);
+	minlen = max_t(u64, r.minlen,
+		       q->limits.discard_granularity) >> bs_shift;
+
+	rgd = gfs2_blk2rgrpd(sdp, start, 0);
+	rgd_end = gfs2_blk2rgrpd(sdp, end - 1, 0);
+
+	if (end <= start ||
+	    minlen > sdp->sd_max_rg_data ||
+	    start > rgd_end->rd_data0 + rgd_end->rd_data)
+		return -EINVAL;
 
 	while (1) {
 
@@ -1295,7 +1302,9 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 			/* Trim each bitmap in the rgrp */
 			for (x = 0; x < rgd->rd_length; x++) {
 				struct gfs2_bitmap *bi = rgd->rd_bits + x;
-				ret = gfs2_rgrp_send_discards(sdp, rgd->rd_data0, NULL, bi, r.minlen, &amt);
+				ret = gfs2_rgrp_send_discards(sdp,
+						rgd->rd_data0, NULL, bi, minlen,
+						&amt);
 				if (ret) {
 					gfs2_glock_dq_uninit(&gh);
 					goto out;
@@ -1324,7 +1333,7 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 
 out:
 	r.len = trimmed << 9;
-	if (argp && copy_to_user(argp, &r, sizeof(r)))
+	if (copy_to_user(argp, &r, sizeof(r)))
 		return -EFAULT;
 
 	return ret;

fs/gfs2/super.c

@@ -810,7 +810,8 @@ static void gfs2_dirty_inode(struct inode *inode, int flags)
 			return;
 		}
 		need_unlock = 1;
-	}
+	} else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
+		return;
 
 	if (current->journal_info == NULL) {
 		ret = gfs2_trans_begin(sdp, RES_DINODE, 0);

fs/gfs2/trans.c

@@ -155,14 +155,22 @@ void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	struct gfs2_bufdata *bd;
 
+	lock_buffer(bh);
+	gfs2_log_lock(sdp);
 	bd = bh->b_private;
 	if (bd)
 		gfs2_assert(sdp, bd->bd_gl == gl);
 	else {
+		gfs2_log_unlock(sdp);
+		unlock_buffer(bh);
 		gfs2_attach_bufdata(gl, bh, meta);
 		bd = bh->b_private;
+		lock_buffer(bh);
+		gfs2_log_lock(sdp);
 	}
 	lops_add(sdp, bd);
+	gfs2_log_unlock(sdp);
+	unlock_buffer(bh);
 }
 
 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)

fs/nfs/nfs4_fs.h

@@ -308,13 +308,13 @@ extern void nfs4_renew_state(struct work_struct *);
 
 /* nfs4state.c */
 struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp);
+struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp);
 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp);
 int nfs4_discover_server_trunking(struct nfs_client *clp,
 			struct nfs_client **);
 int nfs40_discover_server_trunking(struct nfs_client *clp,
 			struct nfs_client **, struct rpc_cred *);
 #if defined(CONFIG_NFS_V4_1)
-struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp);
 struct rpc_cred *nfs4_get_exchange_id_cred(struct nfs_client *clp);
 int nfs41_discover_server_trunking(struct nfs_client *clp,
 			struct nfs_client **, struct rpc_cred *);

fs/nfs/nfs4proc.c

@@ -3782,8 +3782,13 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu
 		goto out_free;
 	}
 	nfs4_write_cached_acl(inode, pages, res.acl_data_offset, res.acl_len);
-	if (buf)
+	if (buf) {
+		if (res.acl_len > buflen) {
+			ret = -ERANGE;
+			goto out_free;
+		}
 		_copy_from_pages(buf, pages, res.acl_data_offset, res.acl_len);
+	}
 out_ok:
 	ret = res.acl_len;
 out_free:

fs/nfs/nfs4xdr.c

@@ -271,6 +271,8 @@ static int nfs4_stat_to_errno(int);
 
 #if defined(CONFIG_NFS_V4_1)
 #define NFS4_MAX_MACHINE_NAME_LEN (64)
+#define IMPL_NAME_LIMIT (sizeof(utsname()->sysname) + sizeof(utsname()->release) + \
+			 sizeof(utsname()->version) + sizeof(utsname()->machine) + 8)
 
 #define encode_exchange_id_maxsz (op_encode_hdr_maxsz + \
 				encode_verifier_maxsz + \
@@ -283,7 +285,7 @@ static int nfs4_stat_to_errno(int);
 				1 /* nii_domain */ + \
 				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
 				1 /* nii_name */ + \
-				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+				XDR_QUADLEN(IMPL_NAME_LIMIT) + \
 				3 /* nii_date */)
 #define decode_exchange_id_maxsz (op_decode_hdr_maxsz + \
 				2 /* eir_clientid */ + \
@@ -1712,7 +1714,7 @@ static void encode_exchange_id(struct xdr_stream *xdr,
 			       struct compound_hdr *hdr)
 {
 	__be32 *p;
-	char impl_name[NFS4_OPAQUE_LIMIT];
+	char impl_name[IMPL_NAME_LIMIT];
 	int len = 0;
 
 	encode_op_hdr(xdr, OP_EXCHANGE_ID, decode_exchange_id_maxsz, hdr);
@@ -1727,7 +1729,7 @@ static void encode_exchange_id(struct xdr_stream *xdr,
 	if (send_implementation_id &&
 	    sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN) > 1 &&
 	    sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN)
-		<= NFS4_OPAQUE_LIMIT + 1)
+		<= sizeof(impl_name) + 1)
 		len = snprintf(impl_name, sizeof(impl_name), "%s %s %s %s",
 			       utsname()->sysname, utsname()->release,
 			       utsname()->version, utsname()->machine);

fs/nfs/write.c

@@ -879,7 +879,7 @@ static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
 {
 	if (nfs_have_delegated_attributes(inode))
 		goto out;
-	if (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
+	if (NFS_I(inode)->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE))
 		return false;
 out:
 	return PageUptodate(page) != 0;
@@ -1823,7 +1823,7 @@ int __init nfs_init_writepagecache(void)
 		goto out_destroy_write_mempool;
 
 	nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
-						      nfs_wdata_cachep);
+						      nfs_cdata_cachep);
 	if (nfs_commit_mempool == NULL)
 		goto out_destroy_commit_cache;
 

net/sunrpc/rpc_pipe.c

@@ -1152,14 +1152,19 @@ static void rpc_kill_sb(struct super_block *sb)
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
 	mutex_lock(&sn->pipefs_sb_lock);
+	if (sn->pipefs_sb != sb) {
+		mutex_unlock(&sn->pipefs_sb_lock);
+		goto out;
+	}
 	sn->pipefs_sb = NULL;
 	mutex_unlock(&sn->pipefs_sb_lock);
-	put_net(net);
 	dprintk("RPC:       sending pipefs UMOUNT notification for net %p%s\n",
 		net, NET_NAME(net));
 	blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
 					   RPC_PIPEFS_UMOUNT,
 					   sb);
+	put_net(net);
+out:
 	kill_litter_super(sb);
 }