On Mon, Sep 04, 2017 at 06:01:02PM +0530, Chandan Rajendra wrote: > On Wednesday, August 30, 2017 5:20:10 AM IST Dave Chinner wrote: > > Everyone who tries to modify mkfs quickly learns that it is a pile > > of spaghetti, the only difference in opinion is whether it is a > > steaming, cold or rotten pile. This patchset attempts to untangle > > the ball of pasta and turn it into a set of clear, obvious > > operations that lead to a filesystem being formatted correctly. > > > > The patch series is really in three parts, splitting the code up > > into roughly three modules. The first part introduces a mkfs > > parameters structure and factors the on-disk formatting code to use > > only information in that structure. The second part introduces a > > command line input structure and factors the input parsing to use > > it. This requires a bunch of temporary code to keep the rest of > > the code working. The third part is factoring the input validation > > and geometry calculation code to use the input structure and put > > the output into the mkfs parameter structure and to remove all the > > temporary support code. > > > > The result is three modules - input parsing, validation+calculations > > and formatting - with well defined data flow between them. This also > > paves the way to supporting config files to set defaults via a > > separate (new) module. The overall data flow now looks like this: > > > > Build defaults --\ > > ---> mkfs_default_params -> CLI -> mkfs_params > > config file -----/ > > > > It is not worth spending a lot of time reviewing the temporary code > > that is added - it gets removed before the end of the series. No > > attempt has been made to ensure that mkfs works 100% correctly after > > each patch is applied - the only guarantee is that it will build > > cleanly. It /should/ work if a bisect lands in the middle of the > > series, but trying to exhaustively test each patch is OK would take > > more effort than it is worth. As such, testing has only been > > performed on the whole series. > > > > The new output from mkfs to indicate where it has sourced the > > defaults from causes xfstests to have conniptions. This requires > > some updates to the mkfs output filters that are already in place > > but it is a fairly trivial update. Test xfs/191 has a couple of new > > failures, but that is because the new code now correctly parses > > things like agsize so that block and sector size based > > specifications work with default mkfs values. This will require test > > updates. > > > > Future work will be to split the xfs_mkfs.c file into a file per > > module (i.e. seperate files for CLI parsing, mkfs formating, > > validation+calculation and, finally, one for config file support), > > but otherwise the majority of the factoring work is now complete. > > > > Comments, flames, etc all welcome. > Hi Dave, > > I am trying to test the "mkfs refactor" patchset on a ppc64 machine. But "git > am ~/mkfs-xfs-rewrite/\[PATCH\ 03_42\]\ mkfs_introduce\ a\ structure\ to\ > hold\ CLI\ options.mbox" fails to apply cleanly on top of xfsprogs/master > (with patches 01 and 02 already applied) branch. Can you please let me know > the id of the topmost commit on which the "mkfs refactor" patches are applied? As I've already posted in the thread: Applies to: $ glo -n 1 origin/for-next 3540b418ba48 xfs_db: btdump should avoid eval for push and pop of cursor $ -Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
