diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index cb4e48baa4ba5b7701464168a87152e03fa9dbcb..6aa9c2e1e8ebecc8977aa78ccb62dfe594dba430 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
+#include <linux/pagemap.h>
#include <linux/string.h>
#include <linux/bio.h>
@@ -75,10 +76,101 @@ static int copy_bio_to_actor(struct bio *bio,
return copied_bytes;
}
+static int squashfs_bio_read_cached(struct bio *fullbio,
+ struct address_space *cache_mapping, u64 index, int length,
+ u64 read_start, u64 read_end, int page_count)
+{
+ struct page *head_to_cache = NULL, *tail_to_cache = NULL;
+ struct block_device *bdev = fullbio->bi_bdev;
+ int start_idx = 0, end_idx = 0;
+ struct bvec_iter_all iter_all;
+ struct bio *bio = NULL;
+ struct bio_vec *bv;
+ int idx = 0;
+ int err = 0;
+
+ bio_for_each_segment_all(bv, fullbio, iter_all) {
+ struct page *page = bv->bv_page;
+
+ if (page->mapping == cache_mapping) {
+ idx++;
+ continue;
+ }
+
+ /*
+ * We only use this when the device block size is the same as
+ * the page size, so read_start and read_end cover full pages.
+ *
+ * Compare these to the original required index and length to
+ * only cache pages which were requested partially, since these
+ * are the ones which are likely to be needed when reading
+ * adjacent blocks.
+ */
+ if (idx == 0 && index != read_start)
+ head_to_cache = page;
+ else if (idx == page_count - 1 && index + length != read_end)
+ tail_to_cache = page;
+
+ if (!bio || idx != end_idx) {
+ struct bio *new = bio_alloc_clone(bdev, fullbio,
+ GFP_NOIO, &fs_bio_set);
+
+ if (bio) {
+ bio_trim(bio, start_idx * PAGE_SECTORS,
+ (end_idx - start_idx) * PAGE_SECTORS);
+ bio_chain(bio, new);
+ submit_bio(bio);
+ }
+
+ bio = new;
+ start_idx = idx;
+ }
+
+ idx++;
+ end_idx = idx;
+ }
+
+ if (bio) {
+ bio_trim(bio, start_idx * PAGE_SECTORS,
+ (end_idx - start_idx) * PAGE_SECTORS);
+ err = submit_bio_wait(bio);
+ bio_put(bio);
+ }
+
+ if (err)
+ return err;
+
+ if (head_to_cache) {
+ int ret = add_to_page_cache_lru(head_to_cache, cache_mapping,
+ read_start >> PAGE_SHIFT,
+ GFP_NOIO);
+
+ if (!ret) {
+ SetPageUptodate(head_to_cache);
+ unlock_page(head_to_cache);
+ }
+
+ }
+
+ if (tail_to_cache) {
+ int ret = add_to_page_cache_lru(tail_to_cache, cache_mapping,
+ (read_end >> PAGE_SHIFT) - 1,
+ GFP_NOIO);
+
+ if (!ret) {
+ SetPageUptodate(tail_to_cache);
+ unlock_page(tail_to_cache);
+ }
+ }
+
+ return 0;
+}
+
static int squashfs_bio_read(struct super_block *sb, u64 index, int length,
struct bio **biop, int *block_offset)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
+ struct address_space *cache_mapping = msblk->cache_mapping;
const u64 read_start = round_down(index, msblk->devblksize);
const sector_t block = read_start >> msblk->devblksize_log2;
const u64 read_end = round_up(index + length, msblk->devblksize);
@@ -98,21 +190,34 @@ static int squashfs_bio_read(struct super_block *sb, u64 index, int length,
for (i = 0; i < page_count; ++i) {
unsigned int len =
min_t(unsigned int, PAGE_SIZE - offset, total_len);
- struct page *page = alloc_page(GFP_NOIO);
+ struct page *page = NULL;
+
+ if (cache_mapping)
+ page = find_get_page(cache_mapping,
+ (read_start >> PAGE_SHIFT) + i);
+ if (!page)
+ page = alloc_page(GFP_NOIO);
if (!page) {
error = -ENOMEM;
goto out_free_bio;
}
- if (!bio_add_page(bio, page, len, offset)) {
- error = -EIO;
- goto out_free_bio;
- }
+
+ /*
+ * Use the __ version to avoid merging since we need each page
+ * to be separate when we check for and avoid cached pages.
+ */
+ __bio_add_page(bio, page, len, offset);
offset = 0;
total_len -= len;
}
- error = submit_bio_wait(bio);
+ if (cache_mapping)
+ error = squashfs_bio_read_cached(bio, cache_mapping, index,
+ length, read_start, read_end,
+ page_count);
+ else
+ error = submit_bio_wait(bio);
if (error)
goto out_free_bio;
diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h
index 72f6f4b378636e8e235c10e3bf2f31a9b5507174..c01998eec14675d81ba34a6b75a0546b08d88827 100644
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -47,6 +47,7 @@ struct squashfs_sb_info {
struct squashfs_cache *block_cache;
struct squashfs_cache *fragment_cache;
struct squashfs_cache *read_page;
+ struct address_space *cache_mapping;
int next_meta_index;
__le64 *id_table;
__le64 *fragment_index;
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index e090fae48e68455e3339552faba85f4fd4aa0132..22e812808e5cf91802e2c95495207b6dd2348c10 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -329,6 +329,19 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
goto failed_mount;
}
+ if (msblk->devblksize == PAGE_SIZE) {
+ struct inode *cache = new_inode(sb);
+
+ if (cache == NULL)
+ goto failed_mount;
+
+ set_nlink(cache, 1);
+ cache->i_size = OFFSET_MAX;
+ mapping_set_gfp_mask(cache->i_mapping, GFP_NOFS);
+
+ msblk->cache_mapping = cache->i_mapping;
+ }
+
msblk->stream = squashfs_decompressor_setup(sb, flags);
if (IS_ERR(msblk->stream)) {
err = PTR_ERR(msblk->stream);
@@ -454,6 +467,8 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
squashfs_cache_delete(msblk->block_cache);
squashfs_cache_delete(msblk->fragment_cache);
squashfs_cache_delete(msblk->read_page);
+ if (msblk->cache_mapping)
+ iput(msblk->cache_mapping->host);
msblk->thread_ops->destroy(msblk);
kfree(msblk->inode_lookup_table);
kfree(msblk->fragment_index);
@@ -572,6 +587,8 @@ static void squashfs_put_super(struct super_block *sb)
squashfs_cache_delete(sbi->block_cache);
squashfs_cache_delete(sbi->fragment_cache);
squashfs_cache_delete(sbi->read_page);
+ if (sbi->cache_mapping)
+ iput(sbi->cache_mapping->host);
sbi->thread_ops->destroy(sbi);
kfree(sbi->id_table);
kfree(sbi->fragment_index);