On Thu, Oct 04, 2018 at 01:24:24PM +0200, David Sterba wrote: > On Fri, Sep 28, 2018 at 07:17:46AM -0400, Josef Bacik wrote: > > may_commit_transaction will skip committing the transaction if we don't > > have enough pinned space or if we're trying to find space for a SYSTEM > > chunk. However if we have pending free block groups in this transaction > > we still want to commit as we may be able to allocate a chunk to make > > our reservation. So instead of just returning ENOSPC, check if we have > > free block groups pending, and if so commit the transaction to allow us > > to use that free space. > > > > Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > Reviewed-by: Omar Sandoval <osandov@xxxxxx> > > --- > > fs/btrfs/extent-tree.c | 33 +++++++++++++++++++-------------- > > 1 file changed, 19 insertions(+), 14 deletions(-) > > > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > > index 1213f573eea2..da73b3e5bc39 100644 > > --- a/fs/btrfs/extent-tree.c > > +++ b/fs/btrfs/extent-tree.c > > @@ -4830,10 +4830,18 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info, > > if (!bytes) > > return 0; > > > > - /* See if there is enough pinned space to make this reservation */ > > - if (__percpu_counter_compare(&space_info->total_bytes_pinned, > > - bytes, > > - BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0) > > + trans = btrfs_join_transaction(fs_info->extent_root); > > + if (IS_ERR(trans)) > > + return -ENOSPC; > > Why do you set override the error to ENOSPC, instead of passing > PTR_ERR(trans)? There are more reasons why btrfs_join_transaction could > fail: EROFS after error, EDQUOT when quotas say no, ENOMEM from > ulist_add, that's just a sample I quickly found. (argh I hit r instead of g, sending again) Because may_commit_transaction is only called during flushing, we don't actually care about the value, just that it failed. Thanks, Josef
