nilfs2: add norecovery mount option
This adds "norecovery" mount option which disables temporal write
access to read-only mounts or snapshots during mount/recovery.
Without this option, write access will be even performed for those
types of mounts; the temporal write access is needed to mount root
file system read-only after an unclean shutdown.
This option will be helpful when user wants to prevent any write
access to the device.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Eric Sandeen <sandeen@redhat.com>
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 72289d2..3fe02cf 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -151,6 +151,8 @@
#define NILFS_MOUNT_BARRIER 0x1000 /* Use block barriers */
#define NILFS_MOUNT_STRICT_ORDER 0x2000 /* Apply strict in-order
semantics also for data */
+#define NILFS_MOUNT_NORECOVERY 0x4000 /* Disable write access during
+ mount-time recovery */
/**