| Message ID | 20210715033704.692967-99-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Memory folios | expand |
On Thu, Jul 15, 2021 at 04:36:24AM +0100, Matthew Wilcox (Oracle) wrote: > Pass a folio around instead of the page, and make sure the offset > is relative to the start of the folio instead of the start of a page. > Also use size_t for offset & length to make it clear that these are byte > counts, and to support >2GB folios in the future. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > fs/iomap/buffered-io.c | 85 ++++++++++++++++++++++-------------------- > 1 file changed, 44 insertions(+), 41 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index fbe4ebc074ce..707a96e36651 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -75,18 +75,18 @@ static void iomap_page_release(struct folio *folio) > } > > /* > - * Calculate the range inside the page that we actually need to read. > + * Calculate the range inside the folio that we actually need to read. > */ > -static void > -iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > - loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp) > +static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, > + loff_t *pos, loff_t length, size_t *offp, size_t *lenp) > { > + struct iomap_page *iop = to_iomap_page(folio); > loff_t orig_pos = *pos; > loff_t isize = i_size_read(inode); > unsigned block_bits = inode->i_blkbits; > unsigned block_size = (1 << block_bits); > - unsigned poff = offset_in_page(*pos); > - unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length); > + size_t poff = offset_in_folio(folio, *pos); > + size_t plen = min_t(loff_t, folio_size(folio) - poff, length); I'm confused about 'size_t poff' here vs. 'unsigned end' later -- why do we need a 64-bit quantity for poff? I suppose some day we might want to have folios larger than 4GB or so, but so far we don't need that large of a byte offset within a page/folio, right? Or are you merely moving the codebase towards using size_t for all byte offsets? The rest of the conversion code looked ok though. --D > unsigned first = poff >> block_bits; > unsigned last = (poff + plen - 1) >> block_bits; > > @@ -124,7 +124,7 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > * page cache for blocks that are entirely outside of i_size. > */ > if (orig_pos <= isize && orig_pos + length > isize) { > - unsigned end = offset_in_page(isize - 1) >> block_bits; > + unsigned end = offset_in_folio(folio, isize - 1) >> block_bits; > > if (first <= end && last > end) > plen -= (last - end) * block_size; > @@ -134,31 +134,31 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > *lenp = plen; > } > > -static void iomap_iop_set_range_uptodate(struct page *page, > - struct iomap_page *iop, unsigned off, unsigned len) > +static void iomap_iop_set_range_uptodate(struct folio *folio, > + struct iomap_page *iop, size_t off, size_t len) > { > - struct inode *inode = page->mapping->host; > + struct inode *inode = folio->mapping->host; > unsigned first = off >> inode->i_blkbits; > unsigned last = (off + len - 1) >> inode->i_blkbits; > unsigned long flags; > > spin_lock_irqsave(&iop->uptodate_lock, flags); > bitmap_set(iop->uptodate, first, last - first + 1); > - if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page))) > - SetPageUptodate(page); > + if (bitmap_full(iop->uptodate, i_blocks_per_folio(inode, folio))) > + folio_mark_uptodate(folio); > spin_unlock_irqrestore(&iop->uptodate_lock, flags); > } > > -static void iomap_set_range_uptodate(struct page *page, > - struct iomap_page *iop, unsigned off, unsigned len) > +static void iomap_set_range_uptodate(struct folio *folio, > + struct iomap_page *iop, size_t off, size_t len) > { > - if (PageError(page)) > + if (folio_test_error(folio)) > return; > > if (iop) > - iomap_iop_set_range_uptodate(page, iop, off, len); > + iomap_iop_set_range_uptodate(folio, iop, off, len); > else > - SetPageUptodate(page); > + folio_mark_uptodate(folio); > } > > static void > @@ -169,15 +169,17 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error) > struct iomap_page *iop = to_iomap_page(folio); > > if (unlikely(error)) { > - ClearPageUptodate(page); > - SetPageError(page); > + folio_clear_uptodate(folio); > + folio_set_error(folio); > } else { > - iomap_set_range_uptodate(page, iop, bvec->bv_offset, > - bvec->bv_len); > + size_t off = (page - &folio->page) * PAGE_SIZE + > + bvec->bv_offset; > + > + iomap_set_range_uptodate(folio, iop, off, bvec->bv_len); > } > > if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending)) > - unlock_page(page); > + folio_unlock(folio); > } > > static void > @@ -237,7 +239,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > struct iomap_page *iop = iomap_page_create(inode, folio); > bool same_page = false, is_contig = false; > loff_t orig_pos = pos; > - unsigned poff, plen; > + size_t poff, plen; > sector_t sector; > > if (iomap->type == IOMAP_INLINE) { > @@ -246,14 +248,14 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > return PAGE_SIZE; > } > > - /* zero post-eof blocks as the page may be mapped */ > - iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); > + /* zero post-eof blocks as the folio may be mapped */ > + iomap_adjust_read_range(inode, folio, &pos, length, &poff, &plen); > if (plen == 0) > goto done; > > if (iomap_block_needs_zeroing(inode, iomap, pos)) { > - zero_user(page, poff, plen); > - iomap_set_range_uptodate(page, iop, poff, plen); > + zero_user(&folio->page, poff, plen); > + iomap_set_range_uptodate(folio, iop, poff, plen); > goto done; > } > > @@ -264,7 +266,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > /* Try to merge into a previous segment if we can */ > sector = iomap_sector(iomap, pos); > if (ctx->bio && bio_end_sector(ctx->bio) == sector) { > - if (__bio_try_merge_page(ctx->bio, page, plen, poff, > + if (__bio_try_merge_page(ctx->bio, &folio->page, plen, poff, > &same_page)) > goto done; > is_contig = true; > @@ -296,7 +298,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > ctx->bio->bi_end_io = iomap_read_end_io; > } > > - bio_add_page(ctx->bio, page, plen, poff); > + bio_add_folio(ctx->bio, folio, plen, poff); > done: > /* > * Move the caller beyond our range so that it keeps making progress. > @@ -531,9 +533,8 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len) > truncate_pagecache_range(inode, max(pos, i_size), pos + len); > } > > -static int > -iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, > - unsigned plen, struct iomap *iomap) > +static int iomap_read_folio_sync(loff_t block_start, struct folio *folio, > + size_t poff, size_t plen, struct iomap *iomap) > { > struct bio_vec bvec; > struct bio bio; > @@ -542,7 +543,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, > bio.bi_opf = REQ_OP_READ; > bio.bi_iter.bi_sector = iomap_sector(iomap, block_start); > bio_set_dev(&bio, iomap->bdev); > - __bio_add_page(&bio, page, plen, poff); > + bio_add_folio(&bio, folio, plen, poff); > return submit_bio_wait(&bio); > } > > @@ -555,14 +556,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > loff_t block_size = i_blocksize(inode); > loff_t block_start = round_down(pos, block_size); > loff_t block_end = round_up(pos + len, block_size); > - unsigned from = offset_in_page(pos), to = from + len, poff, plen; > + size_t from = offset_in_folio(folio, pos), to = from + len; > + size_t poff, plen; > > - if (PageUptodate(page)) > + if (folio_test_uptodate(folio)) > return 0; > - ClearPageError(page); > + folio_clear_error(folio); > > do { > - iomap_adjust_read_range(inode, iop, &block_start, > + iomap_adjust_read_range(inode, folio, &block_start, > block_end - block_start, &poff, &plen); > if (plen == 0) > break; > @@ -575,14 +577,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > if (iomap_block_needs_zeroing(inode, srcmap, block_start)) { > if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE)) > return -EIO; > - zero_user_segments(page, poff, from, to, poff + plen); > + zero_user_segments(&folio->page, poff, from, to, > + poff + plen); > } else { > - int status = iomap_read_page_sync(block_start, page, > + int status = iomap_read_folio_sync(block_start, folio, > poff, plen, srcmap); > if (status) > return status; > } > - iomap_set_range_uptodate(page, iop, poff, plen); > + iomap_set_range_uptodate(folio, iop, poff, plen); > } while ((block_start += plen) < block_end); > > return 0; > @@ -661,7 +664,7 @@ static size_t __iomap_write_end(struct inode *inode, loff_t pos, size_t len, > */ > if (unlikely(copied < len && !PageUptodate(page))) > return 0; > - iomap_set_range_uptodate(page, iop, offset_in_page(pos), len); > + iomap_set_range_uptodate(folio, iop, offset_in_folio(folio, pos), len); > __set_page_dirty_nobuffers(page); > return copied; > } > -- > 2.30.2 >
On Thu, Jul 15, 2021 at 02:26:57PM -0700, Darrick J. Wong wrote: > > + size_t poff = offset_in_folio(folio, *pos); > > + size_t plen = min_t(loff_t, folio_size(folio) - poff, length); > > I'm confused about 'size_t poff' here vs. 'unsigned end' later -- why do > we need a 64-bit quantity for poff? I suppose some day we might want to > have folios larger than 4GB or so, but so far we don't need that large > of a byte offset within a page/folio, right? > > Or are you merely moving the codebase towards using size_t for all byte > offsets? Both. 'end' isn't a byte count -- it's a block count. > > if (orig_pos <= isize && orig_pos + length > isize) { > > - unsigned end = offset_in_page(isize - 1) >> block_bits; > > + unsigned end = offset_in_folio(folio, isize - 1) >> block_bits; That right shift makes it not-a-byte-count. I don't especially want to do all the work needed to support folios >2GB, but I do like using size_t to represent a byte count.
On Thu, Jul 15, 2021 at 11:48:00PM +0100, Matthew Wilcox wrote: > On Thu, Jul 15, 2021 at 02:26:57PM -0700, Darrick J. Wong wrote: > > > + size_t poff = offset_in_folio(folio, *pos); > > > + size_t plen = min_t(loff_t, folio_size(folio) - poff, length); > > > > I'm confused about 'size_t poff' here vs. 'unsigned end' later -- why do > > we need a 64-bit quantity for poff? I suppose some day we might want to > > have folios larger than 4GB or so, but so far we don't need that large > > of a byte offset within a page/folio, right? > > > > Or are you merely moving the codebase towards using size_t for all byte > > offsets? > > Both. 'end' isn't a byte count -- it's a block count. > > > > if (orig_pos <= isize && orig_pos + length > isize) { > > > - unsigned end = offset_in_page(isize - 1) >> block_bits; > > > + unsigned end = offset_in_folio(folio, isize - 1) >> block_bits; > > That right shift makes it not-a-byte-count. > > I don't especially want to do all the work needed to support folios >2GB, > but I do like using size_t to represent a byte count. DOH. Yes, I just noticed that. TBH I doubt anyone's really going to care about 4GB folios anyway. Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index fbe4ebc074ce..707a96e36651 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -75,18 +75,18 @@ static void iomap_page_release(struct folio *folio) } /* - * Calculate the range inside the page that we actually need to read. + * Calculate the range inside the folio that we actually need to read. */ -static void -iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, - loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp) +static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, + loff_t *pos, loff_t length, size_t *offp, size_t *lenp) { + struct iomap_page *iop = to_iomap_page(folio); loff_t orig_pos = *pos; loff_t isize = i_size_read(inode); unsigned block_bits = inode->i_blkbits; unsigned block_size = (1 << block_bits); - unsigned poff = offset_in_page(*pos); - unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length); + size_t poff = offset_in_folio(folio, *pos); + size_t plen = min_t(loff_t, folio_size(folio) - poff, length); unsigned first = poff >> block_bits; unsigned last = (poff + plen - 1) >> block_bits; @@ -124,7 +124,7 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, * page cache for blocks that are entirely outside of i_size. */ if (orig_pos <= isize && orig_pos + length > isize) { - unsigned end = offset_in_page(isize - 1) >> block_bits; + unsigned end = offset_in_folio(folio, isize - 1) >> block_bits; if (first <= end && last > end) plen -= (last - end) * block_size; @@ -134,31 +134,31 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, *lenp = plen; } -static void iomap_iop_set_range_uptodate(struct page *page, - struct iomap_page *iop, unsigned off, unsigned len) +static void iomap_iop_set_range_uptodate(struct folio *folio, + struct iomap_page *iop, size_t off, size_t len) { - struct inode *inode = page->mapping->host; + struct inode *inode = folio->mapping->host; unsigned first = off >> inode->i_blkbits; unsigned last = (off + len - 1) >> inode->i_blkbits; unsigned long flags; spin_lock_irqsave(&iop->uptodate_lock, flags); bitmap_set(iop->uptodate, first, last - first + 1); - if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page))) - SetPageUptodate(page); + if (bitmap_full(iop->uptodate, i_blocks_per_folio(inode, folio))) + folio_mark_uptodate(folio); spin_unlock_irqrestore(&iop->uptodate_lock, flags); } -static void iomap_set_range_uptodate(struct page *page, - struct iomap_page *iop, unsigned off, unsigned len) +static void iomap_set_range_uptodate(struct folio *folio, + struct iomap_page *iop, size_t off, size_t len) { - if (PageError(page)) + if (folio_test_error(folio)) return; if (iop) - iomap_iop_set_range_uptodate(page, iop, off, len); + iomap_iop_set_range_uptodate(folio, iop, off, len); else - SetPageUptodate(page); + folio_mark_uptodate(folio); } static void @@ -169,15 +169,17 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error) struct iomap_page *iop = to_iomap_page(folio); if (unlikely(error)) { - ClearPageUptodate(page); - SetPageError(page); + folio_clear_uptodate(folio); + folio_set_error(folio); } else { - iomap_set_range_uptodate(page, iop, bvec->bv_offset, - bvec->bv_len); + size_t off = (page - &folio->page) * PAGE_SIZE + + bvec->bv_offset; + + iomap_set_range_uptodate(folio, iop, off, bvec->bv_len); } if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending)) - unlock_page(page); + folio_unlock(folio); } static void @@ -237,7 +239,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct iomap_page *iop = iomap_page_create(inode, folio); bool same_page = false, is_contig = false; loff_t orig_pos = pos; - unsigned poff, plen; + size_t poff, plen; sector_t sector; if (iomap->type == IOMAP_INLINE) { @@ -246,14 +248,14 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, return PAGE_SIZE; } - /* zero post-eof blocks as the page may be mapped */ - iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); + /* zero post-eof blocks as the folio may be mapped */ + iomap_adjust_read_range(inode, folio, &pos, length, &poff, &plen); if (plen == 0) goto done; if (iomap_block_needs_zeroing(inode, iomap, pos)) { - zero_user(page, poff, plen); - iomap_set_range_uptodate(page, iop, poff, plen); + zero_user(&folio->page, poff, plen); + iomap_set_range_uptodate(folio, iop, poff, plen); goto done; } @@ -264,7 +266,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, /* Try to merge into a previous segment if we can */ sector = iomap_sector(iomap, pos); if (ctx->bio && bio_end_sector(ctx->bio) == sector) { - if (__bio_try_merge_page(ctx->bio, page, plen, poff, + if (__bio_try_merge_page(ctx->bio, &folio->page, plen, poff, &same_page)) goto done; is_contig = true; @@ -296,7 +298,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, ctx->bio->bi_end_io = iomap_read_end_io; } - bio_add_page(ctx->bio, page, plen, poff); + bio_add_folio(ctx->bio, folio, plen, poff); done: /* * Move the caller beyond our range so that it keeps making progress. @@ -531,9 +533,8 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len) truncate_pagecache_range(inode, max(pos, i_size), pos + len); } -static int -iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, - unsigned plen, struct iomap *iomap) +static int iomap_read_folio_sync(loff_t block_start, struct folio *folio, + size_t poff, size_t plen, struct iomap *iomap) { struct bio_vec bvec; struct bio bio; @@ -542,7 +543,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, bio.bi_opf = REQ_OP_READ; bio.bi_iter.bi_sector = iomap_sector(iomap, block_start); bio_set_dev(&bio, iomap->bdev); - __bio_add_page(&bio, page, plen, poff); + bio_add_folio(&bio, folio, plen, poff); return submit_bio_wait(&bio); } @@ -555,14 +556,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, loff_t block_size = i_blocksize(inode); loff_t block_start = round_down(pos, block_size); loff_t block_end = round_up(pos + len, block_size); - unsigned from = offset_in_page(pos), to = from + len, poff, plen; + size_t from = offset_in_folio(folio, pos), to = from + len; + size_t poff, plen; - if (PageUptodate(page)) + if (folio_test_uptodate(folio)) return 0; - ClearPageError(page); + folio_clear_error(folio); do { - iomap_adjust_read_range(inode, iop, &block_start, + iomap_adjust_read_range(inode, folio, &block_start, block_end - block_start, &poff, &plen); if (plen == 0) break; @@ -575,14 +577,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, if (iomap_block_needs_zeroing(inode, srcmap, block_start)) { if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE)) return -EIO; - zero_user_segments(page, poff, from, to, poff + plen); + zero_user_segments(&folio->page, poff, from, to, + poff + plen); } else { - int status = iomap_read_page_sync(block_start, page, + int status = iomap_read_folio_sync(block_start, folio, poff, plen, srcmap); if (status) return status; } - iomap_set_range_uptodate(page, iop, poff, plen); + iomap_set_range_uptodate(folio, iop, poff, plen); } while ((block_start += plen) < block_end); return 0; @@ -661,7 +664,7 @@ static size_t __iomap_write_end(struct inode *inode, loff_t pos, size_t len, */ if (unlikely(copied < len && !PageUptodate(page))) return 0; - iomap_set_range_uptodate(page, iop, offset_in_page(pos), len); + iomap_set_range_uptodate(folio, iop, offset_in_folio(folio, pos), len); __set_page_dirty_nobuffers(page); return copied; }
Pass a folio around instead of the page, and make sure the offset is relative to the start of the folio instead of the start of a page. Also use size_t for offset & length to make it clear that these are byte counts, and to support >2GB folios in the future. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/iomap/buffered-io.c | 85 ++++++++++++++++++++++-------------------- 1 file changed, 44 insertions(+), 41 deletions(-)