btrfs: compression: migrate compression/decompression paths to folios

For both compression and decompression paths, we always require a
"struct page **pages" and "unsigned long nr_pages", this involves quite
some part of the btrfs compression paths:

- All the compression entry points

- compressed_bio structure
  This affects both compression and decompression.

- async_extent structure

Unfortunately with all those involved parts, there is no good way to
split the conversion into smaller patches while still passing compiling.
So do this in one big conversion in one go.

Please note this is direct page->folio conversion, no change on the page
sized folio requirement yet.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor style fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 38 insertions, 37 deletions

diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index 4ec5dd84b93e..2b232b82c3a8 100644
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -374,25 +374,25 @@ fail:
 	return ERR_PTR(-ENOMEM);
 }
 
-int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
-		u64 start, struct page **pages, unsigned long *out_pages,
-		unsigned long *total_in, unsigned long *total_out)
+int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,
+			 u64 start, struct folio **folios, unsigned long *out_folios,
+			 unsigned long *total_in, unsigned long *total_out)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	zstd_cstream *stream;
 	int ret = 0;
-	int nr_pages = 0;
-	struct page *in_page = NULL;  /* The current page to read */
-	struct page *out_page = NULL; /* The current page to write to */
+	int nr_folios = 0;
+	struct folio *in_folio = NULL;  /* The current folio to read. */
+	struct folio *out_folio = NULL; /* The current folio to write to. */
 	unsigned long tot_in = 0;
 	unsigned long tot_out = 0;
 	unsigned long len = *total_out;
-	const unsigned long nr_dest_pages = *out_pages;
-	unsigned long max_out = nr_dest_pages * PAGE_SIZE;
+	const unsigned long nr_dest_folios = *out_folios;
+	unsigned long max_out = nr_dest_folios * PAGE_SIZE;
 	zstd_parameters params = zstd_get_btrfs_parameters(workspace->req_level,
 							   len);
 
-	*out_pages = 0;
+	*out_folios = 0;
 	*total_out = 0;
 	*total_in = 0;
 
@@ -406,21 +406,21 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 	}
 
 	/* map in the first page of input data */
-	ret = btrfs_compress_find_get_page(mapping, start, &in_page);
+	ret = btrfs_compress_filemap_get_folio(mapping, start, &in_folio);
 	if (ret < 0)
 		goto out;
-	workspace->in_buf.src = kmap_local_page(in_page);
+	workspace->in_buf.src = kmap_local_folio(in_folio, 0);
 	workspace->in_buf.pos = 0;
 	workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
 
 	/* Allocate and map in the output buffer */
-	out_page = folio_page(btrfs_alloc_compr_folio(), 0);
-	if (out_page == NULL) {
+	out_folio = btrfs_alloc_compr_folio();
+	if (out_folio == NULL) {
 		ret = -ENOMEM;
 		goto out;
 	}
-	pages[nr_pages++] = out_page;
-	workspace->out_buf.dst = page_address(out_page);
+	folios[nr_folios++] = out_folio;
+	workspace->out_buf.dst = folio_address(out_folio);
 	workspace->out_buf.pos = 0;
 	workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
 
@@ -455,17 +455,17 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 		if (workspace->out_buf.pos == workspace->out_buf.size) {
 			tot_out += PAGE_SIZE;
 			max_out -= PAGE_SIZE;
-			if (nr_pages == nr_dest_pages) {
+			if (nr_folios == nr_dest_folios) {
 				ret = -E2BIG;
 				goto out;
 			}
-			out_page = folio_page(btrfs_alloc_compr_folio(), 0);
-			if (out_page == NULL) {
+			out_folio = btrfs_alloc_compr_folio();
+			if (out_folio == NULL) {
 				ret = -ENOMEM;
 				goto out;
 			}
-			pages[nr_pages++] = out_page;
-			workspace->out_buf.dst = page_address(out_page);
+			folios[nr_folios++] = out_folio;
+			workspace->out_buf.dst = folio_address(out_folio);
 			workspace->out_buf.pos = 0;
 			workspace->out_buf.size = min_t(size_t, max_out,
 							PAGE_SIZE);
@@ -482,13 +482,13 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 			tot_in += PAGE_SIZE;
 			kunmap_local(workspace->in_buf.src);
 			workspace->in_buf.src = NULL;
-			put_page(in_page);
+			folio_put(in_folio);
 			start += PAGE_SIZE;
 			len -= PAGE_SIZE;
-			ret = btrfs_compress_find_get_page(mapping, start, &in_page);
+			ret = btrfs_compress_filemap_get_folio(mapping, start, &in_folio);
 			if (ret < 0)
 				goto out;
-			workspace->in_buf.src = kmap_local_page(in_page);
+			workspace->in_buf.src = kmap_local_folio(in_folio, 0);
 			workspace->in_buf.pos = 0;
 			workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
 		}
@@ -515,17 +515,17 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 
 		tot_out += PAGE_SIZE;
 		max_out -= PAGE_SIZE;
-		if (nr_pages == nr_dest_pages) {
+		if (nr_folios == nr_dest_folios) {
 			ret = -E2BIG;
 			goto out;
 		}
-		out_page = folio_page(btrfs_alloc_compr_folio(), 0);
-		if (out_page == NULL) {
+		out_folio = btrfs_alloc_compr_folio();
+		if (out_folio == NULL) {
 			ret = -ENOMEM;
 			goto out;
 		}
-		pages[nr_pages++] = out_page;
-		workspace->out_buf.dst = page_address(out_page);
+		folios[nr_folios++] = out_folio;
+		workspace->out_buf.dst = folio_address(out_folio);
 		workspace->out_buf.pos = 0;
 		workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
 	}
@@ -539,10 +539,10 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 	*total_in = tot_in;
 	*total_out = tot_out;
 out:
-	*out_pages = nr_pages;
+	*out_folios = nr_folios;
 	if (workspace->in_buf.src) {
 		kunmap_local(workspace->in_buf.src);
-		put_page(in_page);
+		folio_put(in_folio);
 	}
 	return ret;
 }
@@ -550,12 +550,12 @@ out:
 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
-	struct page **pages_in = cb->compressed_pages;
+	struct folio **folios_in = cb->compressed_folios;
 	size_t srclen = cb->compressed_len;
 	zstd_dstream *stream;
 	int ret = 0;
-	unsigned long page_in_index = 0;
-	unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
+	unsigned long folio_in_index = 0;
+	unsigned long total_folios_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
 	unsigned long buf_start;
 	unsigned long total_out = 0;
 
@@ -567,7 +567,7 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		goto done;
 	}
 
-	workspace->in_buf.src = kmap_local_page(pages_in[page_in_index]);
+	workspace->in_buf.src = kmap_local_folio(folios_in[folio_in_index], 0);
 	workspace->in_buf.pos = 0;
 	workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
 
@@ -604,14 +604,15 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 
 		if (workspace->in_buf.pos == workspace->in_buf.size) {
 			kunmap_local(workspace->in_buf.src);
-			page_in_index++;
-			if (page_in_index >= total_pages_in) {
+			folio_in_index++;
+			if (folio_in_index >= total_folios_in) {
 				workspace->in_buf.src = NULL;
 				ret = -EIO;
 				goto done;
 			}
 			srclen -= PAGE_SIZE;
-			workspace->in_buf.src = kmap_local_page(pages_in[page_in_index]);
+			workspace->in_buf.src =
+				kmap_local_folio(folios_in[folio_in_index], 0);
 			workspace->in_buf.pos = 0;
 			workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
 		}