On 12/01/2010 06:20 PM, liubo wrote: > When the filesystem is readonly, avoid transaction stuff by checking > MS_RDONLY at > start transaction time. >
This patch may lead btrfs panic. Since btrfs allows transaction under readonly fs state, which is a bit weird, btrfs does not even check the returned transaction from start_transaction, although it may return -ENOMEM. With this patch, if btrfs flips readonly or is mounted readonly, to start a transaction will get a -EROFS. So we needs to check transaction more carefully, rather than just leave it alone. thanks, Liu Bo > Signed-off-by: Liu Bo <[email protected]> > --- > 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) -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
