[PATCH 13/21] iomap: Convert readahead and readpage to use a folio

Matthew Wilcox (Oracle)
2021-11-01T21:04:59Z

Handle folios of arbitrary size instead of working in PAGE_SIZE units.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
fs/iomap/buffered-io.c | 53 +++++++++++++++++++++---------------------
1 file changed, 26 insertions(+), 27 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index b5e77d9de4a7..3c68ff26cd16 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -188,8 +188,8 @@ static void iomap_read_end_io(struct bio *bio)
}

struct iomap_readpage_ctx {
- struct page *cur_page;
- bool cur_page_in_bio;
+ struct folio *cur_folio;
+ bool cur_folio_in_bio;
struct bio *bio;
struct readahead_control *rac;
};
@@ -243,8 +243,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
const struct iomap *iomap = &iter->iomap;
loff_t pos = iter->pos + offset;
loff_t length = iomap_length(iter) - offset;
- struct page *page = ctx->cur_page;
- struct folio *folio = page_folio(page);
+ struct folio *folio = ctx->cur_folio;
struct iomap_page *iop;
loff_t orig_pos = pos;
size_t poff, plen;
@@ -265,7 +264,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
goto done;
}

- ctx->cur_page_in_bio = true;
+ ctx->cur_folio_in_bio = true;
if (iop)
atomic_add(plen, &iop->read_bytes_pending);

@@ -273,7 +272,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
if (!ctx->bio ||
bio_end_sector(ctx->bio) != sector ||
!bio_add_folio(ctx->bio, folio, plen, poff)) {
- gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
+ gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
gfp_t orig_gfp = gfp;
unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);

@@ -312,30 +311,31 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
int
iomap_readpage(struct page *page, const struct iomap_ops *ops)
{
+ struct folio *folio = page_folio(page);
struct iomap_iter iter = {
- .inode = page->mapping->host,
- .pos = page_offset(page),
- .len = PAGE_SIZE,
+ .inode = folio->mapping->host,
+ .pos = folio_pos(folio),
+ .len = folio_size(folio),
};
struct iomap_readpage_ctx ctx = {
- .cur_page = page,
+ .cur_folio = folio,
};
int ret;

- trace_iomap_readpage(page->mapping->host, 1);
+ trace_iomap_readpage(iter.inode, 1);

while ((ret = iomap_iter(&iter, ops)) > 0)
iter.processed = iomap_readpage_iter(&iter, &ctx, 0);

if (ret < 0)
- SetPageError(page);
+ folio_set_error(folio);

if (ctx.bio) {
submit_bio(ctx.bio);
- WARN_ON_ONCE(!ctx.cur_page_in_bio);
+ WARN_ON_ONCE(!ctx.cur_folio_in_bio);
} else {
- WARN_ON_ONCE(ctx.cur_page_in_bio);
- unlock_page(page);
+ WARN_ON_ONCE(ctx.cur_folio_in_bio);
+ folio_unlock(folio);
}

/*
@@ -354,15 +354,15 @@ static loff_t iomap_readahead_iter(const struct iomap_iter *iter,
loff_t done, ret;

for (done = 0; done < length; done += ret) {
- if (ctx->cur_page && offset_in_page(iter->pos + done) == 0) {
- if (!ctx->cur_page_in_bio)
- unlock_page(ctx->cur_page);
- put_page(ctx->cur_page);
- ctx->cur_page = NULL;
+ if (ctx->cur_folio &&
+ offset_in_folio(ctx->cur_folio, iter->pos + done) == 0) {
+ if (!ctx->cur_folio_in_bio)
+ folio_unlock(ctx->cur_folio);
+ ctx->cur_folio = NULL;
}
- if (!ctx->cur_page) {
- ctx->cur_page = readahead_page(ctx->rac);
- ctx->cur_page_in_bio = false;
+ if (!ctx->cur_folio) {
+ ctx->cur_folio = readahead_folio(ctx->rac);
+ ctx->cur_folio_in_bio = false;
}
ret = iomap_readpage_iter(iter, ctx, done);
}
@@ -403,10 +403,9 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops)

if (ctx.bio)
submit_bio(ctx.bio);
- if (ctx.cur_page) {
- if (!ctx.cur_page_in_bio)
- unlock_page(ctx.cur_page);
- put_page(ctx.cur_page);
+ if (ctx.cur_folio) {
+ if (!ctx.cur_folio_in_bio)
+ folio_unlock(ctx.cur_folio);
}
}
EXPORT_SYMBOL_GPL(iomap_readahead);
--
2.33.0