On Wed, Dec 15, 2010 at 11:03:46AM -0500, Chris Mason wrote: > Excerpts from liubo's message of 2010-12-15 04:12:14 -0500: > > On 12/15/2010 04:45 PM, Yan, Zheng wrote: > > > On Fri, Dec 3, 2010 at 4:16 PM, liubo <liubo2...@cn.fujitsu.com> wrote: > > >> When the filesystem is readonly, avoid transaction stuff by checking > > >> MS_RDONLY > > >> at start transaction time. > > >> > > >> Signed-off-by: Liu Bo <liubo2...@cn.fujitsu.com> > > >> --- > > >> fs/btrfs/transaction.c | 3 +++ > > >> 1 files changed, 3 insertions(+), 0 deletions(-) > > >> > > >> diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c > > >> index 1fffbc0..14a597d 100644 > > >> --- a/fs/btrfs/transaction.c > > >> +++ b/fs/btrfs/transaction.c > > >> @@ -181,6 +181,9 @@ static struct btrfs_trans_handle > > >> *start_transaction(struct btrfs_root *root, > > >> struct btrfs_trans_handle *h; > > >> struct btrfs_transaction *cur_trans; > > >> int ret; > > >> + > > >> + if (root->fs_info->sb->s_flags & MS_RDONLY) > > >> + return ERR_PTR(-EROFS); > > >> again: > > >> h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); > > >> if (!h) > > > > > > There are cases that we need to start transaction when MS_RDONLY flag is > > > set. > > > For example, remount FS into read-only mode and log replay. > > > > However, is it weird to make changes to disk as fs is in readonly state? > > IMO, btrfs needs to limit the use of these "disk-change while readonly" > > cases, > > as it is not what readonly means. > > reiserfs and ext3 at least have always done this. Log replay is > required even when the FS is readonly. >
Just make sure the underlying disk isn't read only, we had problems with this on ext3 a bit ago. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
