Commit 62719cf3 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Fix nochanges/read_only interaction 



nochanges means "we cannot issue writes at all"; it's possible to go
into a pseudo read-write mode where we pin dirty metadata in memory,
which is used for fsck in dry run mode and doing journal replay on a
read only mount, but we do not want to allow an actual read-write mount
in nochanges mode.

But we do always want to allow early read-write, during recovery - this
patch clarifies that.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 5e329145

fs/bcachefs/fs.c

+2 −2
Original line number Diff line number Diff line
@@ -1630,12 +1630,12 @@ static int bch2_remount(struct super_block *sb, int *flags, char *data) 
	struct bch_opts opts = bch2_opts_empty();

	int ret;



	opt_set(opts, read_only, (*flags & SB_RDONLY) != 0);



	ret = bch2_parse_mount_opts(c, &opts, data);

	if (ret)

		goto err;



	opt_set(opts, read_only, (*flags & SB_RDONLY) != 0);



	if (opts.read_only != c->opts.read_only) {

		down_write(&c->state_lock);

fs/bcachefs/opts.h

+1 −1
Original line number Diff line number Diff line
@@ -389,7 +389,7 @@ enum fsck_err_opts { 
	  BCH2_NO_SB_OPT,		BCH_SB_SECTOR,			\

	  "offset",	"Sector offset of superblock")			\

	x(read_only,			u8,				\

	  OPT_FS,							\

	  OPT_FS|OPT_MOUNT,						\

	  OPT_BOOL(),							\

	  BCH2_NO_SB_OPT,		false,				\

	  NULL,		NULL)						\

fs/bcachefs/recovery.c

+3 −1
Original line number Diff line number Diff line
@@ -1076,7 +1076,9 @@ int bch2_fs_recovery(struct bch_fs *c) 
		bch2_journal_keys_put_initial(c);

	kfree(clean);



	if (!ret && test_bit(BCH_FS_need_delete_dead_snapshots, &c->flags)) {

	if (!ret &&

	    test_bit(BCH_FS_need_delete_dead_snapshots, &c->flags) &&

	    !c->opts.nochanges) {

		bch2_fs_read_write_early(c);

		bch2_delete_dead_snapshots_async(c);

	}

fs/bcachefs/super.c

+12 −11
Original line number Diff line number Diff line
@@ -433,16 +433,6 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early) 
	if (test_bit(BCH_FS_rw, &c->flags))

		return 0;



	if (c->opts.norecovery)

		return -BCH_ERR_erofs_norecovery;



	/*

	 * nochanges is used for fsck -n mode - we have to allow going rw

	 * during recovery for that to work:

	 */

	if (c->opts.nochanges && (!early || c->opts.read_only))

		return -BCH_ERR_erofs_nochanges;



	bch_info(c, "going read-write");



	ret = bch2_sb_members_v2_init(c);
@@ -510,6 +500,12 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early) 


int bch2_fs_read_write(struct bch_fs *c)

{

	if (c->opts.norecovery)

		return -BCH_ERR_erofs_norecovery;



	if (c->opts.nochanges)

		return -BCH_ERR_erofs_nochanges;



	return __bch2_fs_read_write(c, false);

}
@@ -1033,7 +1029,7 @@ int bch2_fs_start(struct bch_fs *c) 


	set_bit(BCH_FS_started, &c->flags);



	if (c->opts.read_only || c->opts.nochanges) {

	if (c->opts.read_only) {

		bch2_fs_read_only(c);

	} else {

		ret = !test_bit(BCH_FS_rw, &c->flags)
@@ -1946,6 +1942,11 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices, 
		BUG_ON(darray_push(&sbs, sb));

	}



	if (opts.nochanges && !opts.read_only) {

		ret = -BCH_ERR_erofs_nochanges;

		goto err_print;

	}



	darray_for_each(sbs, sb)

		if (!best || le64_to_cpu(sb->sb->seq) > le64_to_cpu(best->sb->seq))

			best = sb;