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

12 files changed, 12 insertions, 0 deletions

diff --git a/lib/libspl/Makefile.in b/lib/libspl/Makefile.in
index 040616282..631638962 100644
--- a/lib/libspl/Makefile.in
+++ b/lib/libspl/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/lib/libspl/asm-generic/Makefile.in b/lib/libspl/asm-generic/Makefile.in
index 17d0368ba..60f5f4b48 100644
--- a/lib/libspl/asm-generic/Makefile.in
+++ b/lib/libspl/asm-generic/Makefile.in
@@ -52,6 +52,7 @@ 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/lib/libspl/asm-i386/Makefile.in b/lib/libspl/asm-i386/Makefile.in
index 30e7ffb41..c063f0910 100644
--- a/lib/libspl/asm-i386/Makefile.in
+++ b/lib/libspl/asm-i386/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/lib/libspl/asm-x86_64/Makefile.in b/lib/libspl/asm-x86_64/Makefile.in
index f09efc8ca..e6cb98290 100644
--- a/lib/libspl/asm-x86_64/Makefile.in
+++ b/lib/libspl/asm-x86_64/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/lib/libspl/include/Makefile.in b/lib/libspl/include/Makefile.in
index c6e83b11f..1f3c99b91 100644
--- a/lib/libspl/include/Makefile.in
+++ b/lib/libspl/include/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/lib/libspl/include/ia32/Makefile.in b/lib/libspl/include/ia32/Makefile.in
index 1e913789b..c46466150 100644
--- a/lib/libspl/include/ia32/Makefile.in
+++ b/lib/libspl/include/ia32/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/lib/libspl/include/ia32/sys/Makefile.in b/lib/libspl/include/ia32/sys/Makefile.in
index 50518f6cc..c8ec864f8 100644
--- a/lib/libspl/include/ia32/sys/Makefile.in
+++ b/lib/libspl/include/ia32/sys/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/lib/libspl/include/rpc/Makefile.in b/lib/libspl/include/rpc/Makefile.in
index 47894d8b5..9ceb73f50 100644
--- a/lib/libspl/include/rpc/Makefile.in
+++ b/lib/libspl/include/rpc/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/lib/libspl/include/sys/Makefile.in b/lib/libspl/include/sys/Makefile.in
index 45789862e..a65b9374e 100644
--- a/lib/libspl/include/sys/Makefile.in
+++ b/lib/libspl/include/sys/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/lib/libspl/include/sys/dktp/Makefile.in b/lib/libspl/include/sys/dktp/Makefile.in
index b17910370..c90dbff5b 100644
--- a/lib/libspl/include/sys/dktp/Makefile.in
+++ b/lib/libspl/include/sys/dktp/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/lib/libspl/include/sys/sysevent/Makefile.in b/lib/libspl/include/sys/sysevent/Makefile.in
index 48c345391..e176934ad 100644
--- a/lib/libspl/include/sys/sysevent/Makefile.in
+++ b/lib/libspl/include/sys/sysevent/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/lib/libspl/include/util/Makefile.in b/lib/libspl/include/util/Makefile.in
index bf5b94e0e..16db23b47 100644
--- a/lib/libspl/include/util/Makefile.in
+++ b/lib/libspl/include/util/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 \