Commit 0234576d authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

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: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Eric Sandeen <sandeen@redhat.com>
parent a057d2c0

Documentation/filesystems/nilfs2.txt

+4 −0
Original line number Diff line number Diff line
@@ -70,6 +70,10 @@ order=strict Apply strict in-order semantics that preserves sequence 
			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

============

fs/nilfs2/super.c

+15 −1
Original line number Diff line number Diff line
@@ -479,6 +479,8 @@ static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 
		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 @@ static const struct export_operations nilfs_export_ops = { 


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 @@ static match_table_t tokens = { 
	{Opt_nobarrier, "nobarrier"},

	{Opt_snapshot, "cp=%u"},

	{Opt_order, "order=%s"},

	{Opt_norecovery, "norecovery"},

	{Opt_err, NULL}

};
@@ -608,6 +611,9 @@ static int parse_options(char *options, struct super_block *sb) 
			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 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) 
		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) {

fs/nilfs2/the_nilfs.c

+18 −2
Original line number Diff line number Diff line
@@ -264,8 +264,14 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) 
	int valid_fs = nilfs_valid_fs(nilfs);

	int err;



	if (nilfs_loaded(nilfs))

	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 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) 
		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 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) 
			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);

include/linux/nilfs2_fs.h

+2 −0
Original line number Diff line number Diff line
@@ -151,6 +151,8 @@ struct nilfs_super_root { 
#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 */





/**

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