Linux compat 2.6.39: mount_nodev()

The .get_sb callback has been replaced by a .mount callback
in the file_system_type structure.  When using the new
interface the caller must now use the mount_nodev() helper.

Unfortunately, the new interface no longer passes the vfsmount
down to the zfs layers.  This poses a problem for the existing
implementation because we currently save this pointer in the
super block for latter use.  It provides our only entry point
in to the namespace layer for manipulating certain mount options.

This needed to be done originally to allow commands like
'zfs set atime=off tank' to work properly.  It also allowed me
to keep more of the original Solaris code unmodified.  Under
Solaris there is a 1-to-1 mapping between a mount point and a
file system so this is a fairly natural thing to do.  However,
under Linux they many be multiple entries in the namespace
which reference the same filesystem.  Thus keeping a back
reference from the filesystem to the namespace is complicated.

Rather than introduce some ugly hack to get the vfsmount and
continue as before.  I'm leveraging this API change to update
the ZFS code to do things in a more natural way for Linux.
This has the upside that is resolves the compatibility issue
for the long term and fixes several other minor bugs which
have been reported.

This commit updates the code to remove this vfsmount back
reference entirely.  All modifications to filesystem mount
options are now passed in to the kernel via a '-o remount'.
This is the expected Linux mechanism and allows the namespace
to properly handle any options which apply to it before passing
them on to the file system itself.

Aside from fixing the compatibility issue, removing the
vfsmount has had the benefit of simplifying the code.  This
change which fairly involved has turned out nicely.

Closes #246
Closes #217
Closes #187
Closes #248
Closes #231

13 files changed, 13 insertions, 0 deletions

diff --git a/cmd/Makefile.in b/cmd/Makefile.in
index 988fefc7a..eb8c49cce 100644
--- a/cmd/Makefile.in
+++ b/cmd/Makefile.in
@@ -61,6 +61,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/mount_zfs/Makefile.in b/cmd/mount_zfs/Makefile.in
index 7081fe74c..690b0ff35 100644
--- a/cmd/mount_zfs/Makefile.in
+++ b/cmd/mount_zfs/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/mount_zfs/mount_zfs.c b/cmd/mount_zfs/mount_zfs.c
index 7173f5698..6a2e9ff36 100644
--- a/cmd/mount_zfs/mount_zfs.c
+++ b/cmd/mount_zfs/mount_zfs.c
@@ -96,6 +96,7 @@ static const option_map_t option_map[] = {
 	{ MNTOPT_QUIET,		MS_SILENT,	ZS_COMMENT	},
 #endif
 	/* Custom zfs options */
+	{ MNTOPT_XATTR,		MS_COMMENT,	ZS_COMMENT	},
 	{ MNTOPT_NOXATTR,	MS_COMMENT,	ZS_COMMENT	},
 	{ MNTOPT_ZFSUTIL,	MS_COMMENT,	ZS_ZFSUTIL	},
 	{ NULL,			0,		0		} };
diff --git a/cmd/sas_switch_id/Makefile.in b/cmd/sas_switch_id/Makefile.in
index e32e797be..a2d6430cd 100644
--- a/cmd/sas_switch_id/Makefile.in
+++ b/cmd/sas_switch_id/Makefile.in
@@ -63,6 +63,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zdb/Makefile.in b/cmd/zdb/Makefile.in
index 18502eba5..0740352df 100644
--- a/cmd/zdb/Makefile.in
+++ b/cmd/zdb/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zfs/Makefile.in b/cmd/zfs/Makefile.in
index 1a5f4d3b2..c2b0c6818 100644
--- a/cmd/zfs/Makefile.in
+++ b/cmd/zfs/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zinject/Makefile.in b/cmd/zinject/Makefile.in
index dffcd2e84..ef106b016 100644
--- a/cmd/zinject/Makefile.in
+++ b/cmd/zinject/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zpios/Makefile.in b/cmd/zpios/Makefile.in
index 29e63a84a..0a94f334b 100644
--- a/cmd/zpios/Makefile.in
+++ b/cmd/zpios/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zpool/Makefile.in b/cmd/zpool/Makefile.in
index 1c1481c8c..faf33f8e1 100644
--- a/cmd/zpool/Makefile.in
+++ b/cmd/zpool/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zpool_id/Makefile.in b/cmd/zpool_id/Makefile.in
index eed2156e4..f56c61598 100644
--- a/cmd/zpool_id/Makefile.in
+++ b/cmd/zpool_id/Makefile.in
@@ -63,6 +63,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zpool_layout/Makefile.in b/cmd/zpool_layout/Makefile.in
index 3d4f36335..7027914e7 100644
--- a/cmd/zpool_layout/Makefile.in
+++ b/cmd/zpool_layout/Makefile.in
@@ -63,6 +63,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/ztest/Makefile.in b/cmd/ztest/Makefile.in
index e3718e510..30954f7af 100644
--- a/cmd/ztest/Makefile.in
+++ b/cmd/ztest/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \
diff --git a/cmd/zvol_id/Makefile.in b/cmd/zvol_id/Makefile.in
index 5857046ad..ba0624d68 100644
--- a/cmd/zvol_id/Makefile.in
+++ b/cmd/zvol_id/Makefile.in
@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-insert-inode-locked.m4 \
 	$(top_srcdir)/config/kernel-invalidate-bdev-args.m4 \
 	$(top_srcdir)/config/kernel-kobj-name-len.m4 \
+	$(top_srcdir)/config/kernel-mount-nodev.m4 \
 	$(top_srcdir)/config/kernel-open-bdev-exclusive.m4 \
 	$(top_srcdir)/config/kernel-rq-for-each_segment.m4 \
 	$(top_srcdir)/config/kernel-rq-is_sync.m4 \