| Message ID | 166722777223.2555743.162508599131141451.stgit@warthog.procyon.org.uk |
|---|---|
| Headers | show |
| Series | iov_iter: Provide a function to extract/pin/get pages from an iteraor | expand |
On Mon, Oct 31, 2022 at 02:49:32PM +0000, David Howells wrote: > I added a macro by which you can query an iterator to find out how the > extraction function will treat the pages (it returns 0, FOLL_GET or FOLL_PIN > as appropriate). Note that it's a macro to avoid #inclusion of linux/mm.h in > linux/uio.h. I'd support moving FOLL_* definitions to mm_types.h along with FAULT_FLAG_* and VM_FAULT_*.
On 10/31/22 07:52, Matthew Wilcox wrote: > On Mon, Oct 31, 2022 at 02:49:32PM +0000, David Howells wrote: >> I added a macro by which you can query an iterator to find out how the >> extraction function will treat the pages (it returns 0, FOLL_GET or FOLL_PIN >> as appropriate). Note that it's a macro to avoid #inclusion of linux/mm.h in >> linux/uio.h. > > I'd support moving FOLL_* definitions to mm_types.h along with > FAULT_FLAG_* and VM_FAULT_*. +1, great idea. The use of FOLL_* without including it's .h directly was the first thing that jumped out at me when I just started looking at this. And these really are mm types, so yes. thanks,
Hi Al, Here's a patch to provide a function to extract a list of pages from an iterator, getting pins of refs on them as appropriate. I added a macro by which you can query an iterator to find out how the extraction function will treat the pages (it returns 0, FOLL_GET or FOLL_PIN as appropriate). Note that it's a macro to avoid #inclusion of linux/mm.h in linux/uio.h. I've added another crude, incomplete patch to make cifs use it a bit as an example. Note that cifs won't work properly with this under all circumstances, particularly if it decides to split the rdata or wdata record - but it seems to work for small I/Os. David --- David Howells (2): iov_iter: Add a function to extract a page list from an iterator cifs: Test use of iov_iter_extract_pages() and iov_iter_extract_mode() fs/cifs/cifsglob.h | 2 + fs/cifs/file.c | 93 +++++++++---- include/linux/uio.h | 26 ++++ lib/iov_iter.c | 333 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 427 insertions(+), 27 deletions(-)