On Thu, Nov 9, 2023 at 10:55 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > The patch titled > Subject: mm: add folio_fill_tail() and use it in iomap > has been added to the -mm mm-unstable branch. Its filename is > mm-add-folio_fill_tail-and-use-it-in-iomap.patch > > This patch will shortly appear at > https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-folio_fill_tail-and-use-it-in-iomap.patch > > This patch will later appear in the mm-unstable branch at > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** > > The -mm tree is included into linux-next via the mm-everything > branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > and is updated there every 2-3 working days > > ------------------------------------------------------ > From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> > Subject: mm: add folio_fill_tail() and use it in iomap > Date: Tue, 7 Nov 2023 21:26:41 +0000 > > The iomap code was limited to PAGE_SIZE bytes; generalise it to cover > an arbitrary-sized folio, and move it to be a common helper. > > Link: https://lkml.kernel.org/r/20231107212643.3490372-3-willy@xxxxxxxxxxxxx > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx> > Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx> > Cc: Darrick J. Wong <djwong@xxxxxxxxxx> > Cc: Theodore Ts'o <tytso@xxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > fs/iomap/buffered-io.c | 14 ++------------ > include/linux/highmem.h | 38 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 40 insertions(+), 12 deletions(-) > > --- a/fs/iomap/buffered-io.c~mm-add-folio_fill_tail-and-use-it-in-iomap > +++ a/fs/iomap/buffered-io.c > @@ -305,28 +305,18 @@ static int iomap_read_inline_data(const > { > const struct iomap *iomap = iomap_iter_srcmap(iter); > size_t size = i_size_read(iter->inode) - iomap->offset; > - size_t poff = offset_in_page(iomap->offset); > size_t offset = offset_in_folio(folio, iomap->offset); > - void *addr; > > if (folio_test_uptodate(folio)) > return 0; > > - if (WARN_ON_ONCE(size > PAGE_SIZE - poff)) > - return -EIO; > - if (WARN_ON_ONCE(size > PAGE_SIZE - > - offset_in_page(iomap->inline_data))) > - return -EIO; > if (WARN_ON_ONCE(size > iomap->length)) > return -EIO; > if (offset > 0) > ifs_alloc(iter->inode, folio, iter->flags); > > - addr = kmap_local_folio(folio, offset); > - memcpy(addr, iomap->inline_data, size); > - memset(addr + size, 0, PAGE_SIZE - poff - size); > - kunmap_local(addr); > - iomap_set_range_uptodate(folio, offset, PAGE_SIZE - poff); > + folio_fill_tail(folio, offset, iomap->inline_data, size); > + iomap_set_range_uptodate(folio, offset, folio_size(folio) - offset); > return 0; > } > > --- a/include/linux/highmem.h~mm-add-folio_fill_tail-and-use-it-in-iomap > +++ a/include/linux/highmem.h > @@ -522,6 +522,44 @@ static inline __must_check void *folio_z > } > > /** > + * folio_fill_tail - Copy some data to a folio and pad with zeroes. > + * @folio: The destination folio. > + * @offset: The offset into @folio at which to start copying. > + * @from: The data to copy. > + * @len: How many bytes of data to copy. > + * > + * This function is most useful for filesystems which support inline data. > + * When they want to copy data from the inode into the page cache, this > + * function does everything for them. It supports large folios even on > + * HIGHMEM configurations. > + */ > +static inline void folio_fill_tail(struct folio *folio, size_t offset, > + const char *from, size_t len) > +{ > + char *to = kmap_local_folio(folio, offset); > + > + VM_BUG_ON(offset + len > folio_size(folio)); > + > + if (folio_test_highmem(folio)) { > + size_t max = PAGE_SIZE - offset_in_page(offset); > + > + while (len > max) { > + memcpy(to, from, max); > + kunmap_local(to); > + len -= max; > + from += max; > + offset += max; > + max = PAGE_SIZE; > + to = kmap_local_folio(folio, offset); > + } > + } > + > + memcpy(to, from, len); > + to = folio_zero_tail(folio, offset, to); Please note the fix to this patch which I've just posted, to = folio_zero_tail(folio, offset + len, to + len); > + kunmap_local(to); > +} > + > +/** > * memcpy_from_file_folio - Copy some bytes from a file folio. > * @to: The destination buffer. > * @folio: The folio to copy from. > _ > > Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are > > mm-add-folio_zero_tail-and-use-it-in-ext4.patch > mm-add-folio_fill_tail-and-use-it-in-iomap.patch > gfs2-convert-stuffed_readpage-to-stuffed_read_folio.patch > mm-remove-test_set_page_writeback.patch > afs-do-not-test-the-return-value-of-folio_start_writeback.patch > smb-do-not-test-the-return-value-of-folio_start_writeback.patch > mm-return-void-from-folio_start_writeback-and-related-functions.patch > mm-make-mapping_evict_folio-the-preferred-way-to-evict-clean-folios.patch > mm-convert-__do_fault-to-use-a-folio.patch > mm-use-mapping_evict_folio-in-truncate_error_page.patch > mm-convert-soft_offline_in_use_page-to-use-a-folio.patch > mm-convert-isolate_page-to-mf_isolate_folio.patch > mm-remove-invalidate_inode_page.patch > Thanks, Andreas
