diff options
| -rw-r--r-- | fs/squashfs/block.c | 117 | ||||
| -rw-r--r-- | fs/squashfs/squashfs_fs_sb.h | 1 | ||||
| -rw-r--r-- | fs/squashfs/super.c | 17 |
3 files changed, 129 insertions, 6 deletions
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index cb4e48baa4ba..6aa9c2e1e8eb 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 72f6f4b37863..c01998eec146 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 e090fae48e68..22e812808e5c 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 @@ failed_mount: 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); |