1 files changed, 147 insertions, 9 deletions

diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index 89d492916dea..8ba8c4c50770 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -39,6 +39,7 @@
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
+#include "page_actor.h"
 
 /*
  * Locate cache slot in range [offset, index] for specified inode.  If
@@ -444,8 +445,9 @@ static int squashfs_readpage_sparse(struct page *page, int expected)
 	return 0;
 }
 
-static int squashfs_readpage(struct file *file, struct page *page)
+static int squashfs_read_folio(struct file *file, struct folio *folio)
 {
+	struct page *page = &folio->page;
 	struct inode *inode = page->mapping->host;
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
 	int index = page->index >> (msblk->block_log - PAGE_SHIFT);
@@ -453,7 +455,7 @@ static int squashfs_readpage(struct file *file, struct page *page)
 	int expected = index == file_end ?
 			(i_size_read(inode) & (msblk->block_size - 1)) :
 			 msblk->block_size;
-	int res;
+	int res = 0;
 	void *pageaddr;
 
 	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
@@ -466,14 +468,15 @@ static int squashfs_readpage(struct file *file, struct page *page)
 	if (index < file_end || squashfs_i(inode)->fragment_block ==
 					SQUASHFS_INVALID_BLK) {
 		u64 block = 0;
-		int bsize = read_blocklist(inode, index, &block);
-		if (bsize < 0)
+
+		res = read_blocklist(inode, index, &block);
+		if (res < 0)
 			goto error_out;
 
-		if (bsize == 0)
+		if (res == 0)
 			res = squashfs_readpage_sparse(page, expected);
 		else
-			res = squashfs_readpage_block(page, block, bsize, expected);
+			res = squashfs_readpage_block(page, block, res, expected);
 	} else
 		res = squashfs_readpage_fragment(page, expected);
 
@@ -487,14 +490,149 @@ out:
 	memset(pageaddr, 0, PAGE_SIZE);
 	kunmap_atomic(pageaddr);
 	flush_dcache_page(page);
-	if (!PageError(page))
+	if (res == 0)
 		SetPageUptodate(page);
 	unlock_page(page);
 
-	return 0;
+	return res;
+}
+
+static int squashfs_readahead_fragment(struct page **page,
+	unsigned int pages, unsigned int expected)
+{
+	struct inode *inode = page[0]->mapping->host;
+	struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb,
+		squashfs_i(inode)->fragment_block,
+		squashfs_i(inode)->fragment_size);
+	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	unsigned int n, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
+	int error = buffer->error;
+
+	if (error)
+		goto out;
+
+	expected += squashfs_i(inode)->fragment_offset;
+
+	for (n = 0; n < pages; n++) {
+		unsigned int base = (page[n]->index & mask) << PAGE_SHIFT;
+		unsigned int offset = base + squashfs_i(inode)->fragment_offset;
+
+		if (expected > offset) {
+			unsigned int avail = min_t(unsigned int, expected -
+				offset, PAGE_SIZE);
+
+			squashfs_fill_page(page[n], buffer, offset, avail);
+		}
+
+		unlock_page(page[n]);
+		put_page(page[n]);
+	}
+
+out:
+	squashfs_cache_put(buffer);
+	return error;
 }
 
+static void squashfs_readahead(struct readahead_control *ractl)
+{
+	struct inode *inode = ractl->mapping->host;
+	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	size_t mask = (1UL << msblk->block_log) - 1;
+	unsigned short shift = msblk->block_log - PAGE_SHIFT;
+	loff_t start = readahead_pos(ractl) & ~mask;
+	size_t len = readahead_length(ractl) + readahead_pos(ractl) - start;
+	struct squashfs_page_actor *actor;
+	unsigned int nr_pages = 0;
+	struct page **pages;
+	int i, file_end = i_size_read(inode) >> msblk->block_log;
+	unsigned int max_pages = 1UL << shift;
+
+	readahead_expand(ractl, start, (len | mask) + 1);
+
+	pages = kmalloc_array(max_pages, sizeof(void *), GFP_KERNEL);
+	if (!pages)
+		return;
+
+	for (;;) {
+		pgoff_t index;
+		int res, bsize;
+		u64 block = 0;
+		unsigned int expected;
+		struct page *last_page;
+
+		expected = start >> msblk->block_log == file_end ?
+			   (i_size_read(inode) & (msblk->block_size - 1)) :
+			    msblk->block_size;
+
+		max_pages = (expected + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+		nr_pages = __readahead_batch(ractl, pages, max_pages);
+		if (!nr_pages)
+			break;
+
+		if (readahead_pos(ractl) >= i_size_read(inode))
+			goto skip_pages;
+
+		index = pages[0]->index >> shift;
+
+		if ((pages[nr_pages - 1]->index >> shift) != index)
+			goto skip_pages;
+
+		if (index == file_end && squashfs_i(inode)->fragment_block !=
+						SQUASHFS_INVALID_BLK) {
+			res = squashfs_readahead_fragment(pages, nr_pages,
+							  expected);
+			if (res)
+				goto skip_pages;
+			continue;
+		}
+
+		bsize = read_blocklist(inode, index, &block);
+		if (bsize == 0)
+			goto skip_pages;
+
+		actor = squashfs_page_actor_init_special(msblk, pages, nr_pages,
+							 expected);
+		if (!actor)
+			goto skip_pages;
+
+		res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);
+
+		last_page = squashfs_page_actor_free(actor);
+
+		if (res == expected) {
+			int bytes;
+
+			/* Last page (if present) may have trailing bytes not filled */
+			bytes = res % PAGE_SIZE;
+			if (index == file_end && bytes && last_page)
+				memzero_page(last_page, bytes,
+					     PAGE_SIZE - bytes);
+
+			for (i = 0; i < nr_pages; i++) {
+				flush_dcache_page(pages[i]);
+				SetPageUptodate(pages[i]);
+			}
+		}
+
+		for (i = 0; i < nr_pages; i++) {
+			unlock_page(pages[i]);
+			put_page(pages[i]);
+		}
+	}
+
+	kfree(pages);
+	return;
+
+skip_pages:
+	for (i = 0; i < nr_pages; i++) {
+		unlock_page(pages[i]);
+		put_page(pages[i]);
+	}
+	kfree(pages);
+}
 
 const struct address_space_operations squashfs_aops = {
-	.readpage = squashfs_readpage
+	.read_folio = squashfs_read_folio,
+	.readahead = squashfs_readahead
 };