Re: [RFC 04/10] fs/dax: Don't track page mapping/index

2024-04-15 Thread Dan Williams
Alistair Popple wrote: > > Dan Williams writes: > > > Alistair Popple wrote: > >> I was initially concerned about these cases because I was wondering if > >> folio subpages could ever get different mappings and the shared case > >> implied they could. But it seems that's xfs specific and there i

Re: [RFC 04/10] fs/dax: Don't track page mapping/index

2024-04-15 Thread Alistair Popple
Dan Williams writes: > Alistair Popple wrote: >> I was initially concerned about these cases because I was wondering if >> folio subpages could ever get different mappings and the shared case >> implied they could. But it seems that's xfs specific and there is a >> separate mechanism to deal wi

Re: [RFC 04/10] fs/dax: Don't track page mapping/index

2024-04-15 Thread Dan Williams
Alistair Popple wrote: > I was initially concerned about these cases because I was wondering if > folio subpages could ever get different mappings and the shared case > implied they could. But it seems that's xfs specific and there is a > separate mechanism to deal with looking up ->mapping/index f

Re: [PATCH ndctl 2/2] daxctl/device.c: Fix error propagation in do_xaction_device()

2024-04-15 Thread Dave Jiang
On 4/12/24 2:05 PM, Vishal Verma wrote: > The loop through the provided list of devices in do_xaction_device() > returns the status based on whatever the last device did. Since the > order of processing devices, especially in cases like the 'all' keyword, > can be effectively random, this can le

Re: [PATCH ndctl 1/2] daxctl/device.c: Handle special case of destroying daxX.0

2024-04-15 Thread Dave Jiang
On 4/12/24 2:05 PM, Vishal Verma wrote: > The kernel has special handling for destroying the 0th dax device under > any given DAX region (daxX.0). It ensures the size is set to 0, but > doesn't actually remove the device, instead it returns an EBUSY, > indicating that this device cannot be remov

Re: [RFC 05/10] fs/dax: Refactor wait for dax idle page

2024-04-15 Thread Alistair Popple
John Hubbard writes: > On 4/10/24 5:57 PM, Alistair Popple wrote: > ... >> diff --git a/include/linux/dax.h b/include/linux/dax.h >> index 22cd990..bced4d4 100644 >> --- a/include/linux/dax.h >> +++ b/include/linux/dax.h >> @@ -212,6 +212,17 @@ int dax_zero_range(struct inode *inode, loff_t pos

Re: [RFC 04/10] fs/dax: Don't track page mapping/index

2024-04-15 Thread Alistair Popple
Dan Williams writes: > Jan Kara wrote: >> On Thu 11-04-24 10:57:25, Alistair Popple wrote: >> > The page->mapping and page->index fields are normally used by the >> > pagecache and rmap for looking up virtual mappings of pages. FS DAX >> > implements it's own kind of page cache and rmap look up