Fix 'zfs set volsize=N pool/dataset'

This change fixes a kernel panic which would occur when resizing
a dataset which was not open.  The objset_t stored in the
zvol_state_t will be set to NULL when the block device is closed.
To avoid this issue we pass the correct objset_t as the third arg.

The code has also been updated to correctly notify the kernel
when the block device capacity changes.  For 2.6.28 and newer
kernels the capacity change will be immediately detected.  For
earlier kernels the capacity change will be detected when the
device is next opened.  This is a known limitation of older
kernels.

Online ext3 resize test case passes on 2.6.28+ kernels:
$ dd if=/dev/zero of=/tmp/zvol bs=1M count=1 seek=1023
$ zpool create tank /tmp/zvol
$ zfs create -V 500M tank/zd0
$ mkfs.ext3 /dev/zd0
$ mkdir /mnt/zd0
$ mount /dev/zd0 /mnt/zd0
$ df -h /mnt/zd0
$ zfs set volsize=800M tank/zd0
$ resize2fs /dev/zd0
$ df -h /mnt/zd0

Original-patch-by: Fajar A. Nugraha <[email protected]>
Closes #68
Closes #84

11 files changed, 11 insertions, 0 deletions

diff --git a/cmd/Makefile.in b/cmd/Makefile.in
index d75ea03f7..1d096398c 100644
--- a/cmd/Makefile.in
+++ b/cmd/Makefile.in
@@ -51,6 +51,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/mount_zfs/Makefile.in b/cmd/mount_zfs/Makefile.in
index cb44c195e..cec6e93dd 100644
--- a/cmd/mount_zfs/Makefile.in
+++ b/cmd/mount_zfs/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zdb/Makefile.in b/cmd/zdb/Makefile.in
index 32938abbe..a531ab158 100644
--- a/cmd/zdb/Makefile.in
+++ b/cmd/zdb/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zfs/Makefile.in b/cmd/zfs/Makefile.in
index caeae5c19..2698dd446 100644
--- a/cmd/zfs/Makefile.in
+++ b/cmd/zfs/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zinject/Makefile.in b/cmd/zinject/Makefile.in
index a84f06829..a338c4874 100644
--- a/cmd/zinject/Makefile.in
+++ b/cmd/zinject/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zpios/Makefile.in b/cmd/zpios/Makefile.in
index 258f36d23..14ea87299 100644
--- a/cmd/zpios/Makefile.in
+++ b/cmd/zpios/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zpool/Makefile.in b/cmd/zpool/Makefile.in
index ea0e56ae2..4f2b5287d 100644
--- a/cmd/zpool/Makefile.in
+++ b/cmd/zpool/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zpool_id/Makefile.in b/cmd/zpool_id/Makefile.in
index b6da33ce6..2264d4f11 100644
--- a/cmd/zpool_id/Makefile.in
+++ b/cmd/zpool_id/Makefile.in
@@ -53,6 +53,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zpool_layout/Makefile.in b/cmd/zpool_layout/Makefile.in
index 6939e4bd2..43172fe66 100644
--- a/cmd/zpool_layout/Makefile.in
+++ b/cmd/zpool_layout/Makefile.in
@@ -53,6 +53,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/ztest/Makefile.in b/cmd/ztest/Makefile.in
index 6a887e9e2..e8c24845c 100644
--- a/cmd/ztest/Makefile.in
+++ b/cmd/ztest/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \
diff --git a/cmd/zvol_id/Makefile.in b/cmd/zvol_id/Makefile.in
index 7ff4e45de..50c5fcb96 100644
--- a/cmd/zvol_id/Makefile.in
+++ b/cmd/zvol_id/Makefile.in
@@ -54,6 +54,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blk-rq-pos.m4 \
 	$(top_srcdir)/config/kernel-blk-rq-sectors.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
+	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \
 	$(top_srcdir)/config/kernel-evict-inode.m4 \
 	$(top_srcdir)/config/kernel-fmode-t.m4 \