On Fri, May 31, 2024 at 07:13:05AM -0700, Christoph Hellwig wrote: > On Fri, May 31, 2024 at 07:10:00AM -0700, Darrick J. Wong wrote: > > On Fri, May 31, 2024 at 05:42:37AM -0700, Christoph Hellwig wrote: > > > > - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp); > > > > + resblks = XFS_IS_REALTIME_INODE(ip) ? XFS_DIOSTRAT_SPACE_RES(mp, 0) : 0; > > > > > > This probably wants a comment explaining that we need the block > > > reservation for bmap btree block allocations / splits that can happen > > > because we can split a written extent into one written and one > > > unwritten, while for the data fork we'll always just shorten or > > > remove extents. > > > > "for the data fork"? <confused> > > > > This always runs on the data fork. Did you mean "for files with alloc > > unit > 1 fsblock"? > > Sorry, it was meant to say for the data device. My whole journey > to check if this could get called for the attr fork twisted my mind. I really hope not -- all writes to the attr fork have known sizes at syscall time, and appending doesn't even make sense. > But you have a good point that even for the rt device we only need > the reservation for an rtextsize > 1. <nod> --D
