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/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt
index cbd8779..4949fca 100644
--- a/Documentation/filesystems/nilfs2.txt
+++ b/Documentation/filesystems/nilfs2.txt
@@ -70,6 +70,10 @@
blocks. That means, it is guaranteed that no
overtaking of events occurs in the recovered file
system after a crash.
+norecovery Disable recovery of the filesystem on mount.
+ This disables every write access on the device for
+ read-only mounts or snapshots. This option will fail
+ for r/w mounts on an unclean volume.
NILFS2 usage
============
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 990ead4..5403b3e 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -479,6 +479,8 @@
seq_printf(seq, ",errors=panic");
if (nilfs_test_opt(sbi, STRICT_ORDER))
seq_printf(seq, ",order=strict");
+ if (nilfs_test_opt(sbi, NORECOVERY))
+ seq_printf(seq, ",norecovery");
return 0;
}
@@ -547,7 +549,7 @@
enum {
Opt_err_cont, Opt_err_panic, Opt_err_ro,
- Opt_nobarrier, Opt_snapshot, Opt_order,
+ Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
Opt_err,
};
@@ -558,6 +560,7 @@
{Opt_nobarrier, "nobarrier"},
{Opt_snapshot, "cp=%u"},
{Opt_order, "order=%s"},
+ {Opt_norecovery, "norecovery"},
{Opt_err, NULL}
};
@@ -608,6 +611,9 @@
sbi->s_snapshot_cno = option;
nilfs_set_opt(sbi, SNAPSHOT);
break;
+ case Opt_norecovery:
+ nilfs_set_opt(sbi, NORECOVERY);
+ break;
default:
printk(KERN_ERR
"NILFS: Unrecognized mount option \"%s\"\n", p);
@@ -863,6 +869,14 @@
goto restore_opts;
}
+ if (!nilfs_valid_fs(nilfs)) {
+ printk(KERN_WARNING "NILFS (device %s): couldn't "
+ "remount because the filesystem is in an "
+ "incomplete recovery state.\n", sb->s_id);
+ err = -EINVAL;
+ goto restore_opts;
+ }
+
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
goto out;
if (*flags & MS_RDONLY) {
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 890a8d3..6241e17 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -264,8 +264,14 @@
int valid_fs = nilfs_valid_fs(nilfs);
int err;
- if (nilfs_loaded(nilfs))
- return 0;
+ if (nilfs_loaded(nilfs)) {
+ if (valid_fs ||
+ ((s_flags & MS_RDONLY) && nilfs_test_opt(sbi, NORECOVERY)))
+ return 0;
+ printk(KERN_ERR "NILFS: the filesystem is in an incomplete "
+ "recovery state.\n");
+ return -EINVAL;
+ }
if (!valid_fs) {
printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
@@ -295,6 +301,11 @@
goto skip_recovery;
if (s_flags & MS_RDONLY) {
+ if (nilfs_test_opt(sbi, NORECOVERY)) {
+ printk(KERN_INFO "NILFS: norecovery option specified. "
+ "skipping roll-forward recovery\n");
+ goto skip_recovery;
+ }
if (really_read_only) {
printk(KERN_ERR "NILFS: write access "
"unavailable, cannot proceed.\n");
@@ -302,6 +313,11 @@
goto failed_unload;
}
sbi->s_super->s_flags &= ~MS_RDONLY;
+ } else if (nilfs_test_opt(sbi, NORECOVERY)) {
+ printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
+ "option was specified for a read/write mount\n");
+ err = -EINVAL;
+ goto failed_unload;
}
err = nilfs_recover_logical_segments(nilfs, sbi, &ri);
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 */
/**
