Revert "Squashfs: optimize reading uncompressed data"

This reverts commit d9aa8ddc51cbd7d3bc68d664f9b71548a04447e9.

diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 2eb66de..8a75d81 100644 (file)
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -206,22 +206,6 @@ static void squashfs_bio_end_io(struct bio *bio)
        kfree(bio_req);
 }
 
-static int bh_is_optional(struct squashfs_read_request *req, int idx)
-{
-       int start_idx, end_idx;
-       struct squashfs_sb_info *msblk = req->sb->s_fs_info;
-
-       start_idx = (idx * msblk->devblksize - req->offset) / PAGE_CACHE_SIZE;
-       end_idx = ((idx + 1) * msblk->devblksize - req->offset + 1) / PAGE_CACHE_SIZE;
-       if (start_idx >= req->output->pages)
-               return 1;
-       if (start_idx < 0)
-               start_idx = end_idx;
-       if (end_idx >= req->output->pages)
-               end_idx = start_idx;
-       return !req->output->page[start_idx] && !req->output->page[end_idx];
-}
-
 static int actor_getblks(struct squashfs_read_request *req, u64 block)
 {
        int i;
@@ -231,15 +215,6 @@ static int actor_getblks(struct squashfs_read_request *req, u64 block)
                return -ENOMEM;
 
        for (i = 0; i < req->nr_buffers; ++i) {
-               /*
-                * When dealing with an uncompressed block, the actor may
-                * contains NULL pages. There's no need to read the buffers
-                * associated with these pages.
-                */
-               if (!req->compressed && bh_is_optional(req, i)) {
-                       req->bh[i] = NULL;
-                       continue;
-               }
                req->bh[i] = sb_getblk(req->sb, block + i);
                if (!req->bh[i]) {
                        while (--i) {

diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c
index c97af4c..3fb4ce2 100644 (file)
--- a/fs/squashfs/file_direct.c
+++ b/fs/squashfs/file_direct.c
@@ -114,38 +114,15 @@ int squashfs_readpages_block(struct page *target_page,
        struct squashfs_page_actor *actor;
        struct inode *inode = mapping->host;
        struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
-       int start_index, end_index, file_end, actor_pages, res;
+       int file_end = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
        int mask = (1 << (msblk->block_log - PAGE_CACHE_SHIFT)) - 1;
+       int start_index = page_index & ~mask;
+       int end_index = start_index | mask;
+       int actor_pages, res;
 
-       /*
-        * If readpage() is called on an uncompressed datablock, we can just
-        * read the pages instead of fetching the whole block.
-        * This greatly improves the performance when a process keep doing
-        * random reads because we only fetch the necessary data.
-        * The readahead algorithm will take care of doing speculative reads
-        * if necessary.
-        * We can't read more than 1 block even if readahead provides use more
-        * pages because we don't know yet if the next block is compressed or
-        * not.
-        */
-       if (bsize && !SQUASHFS_COMPRESSED_BLOCK(bsize)) {
-               u64 block_end = block + msblk->block_size;
-
-               block += (page_index & mask) * PAGE_CACHE_SIZE;
-               actor_pages = (block_end - block) / PAGE_CACHE_SIZE;
-               if (*nr_pages < actor_pages)
-                       actor_pages = *nr_pages;
-               start_index = page_index;
-               bsize = min_t(int, bsize, (PAGE_CACHE_SIZE * actor_pages)
-                                         | SQUASHFS_COMPRESSED_BIT_BLOCK);
-       } else {
-               file_end = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
-               start_index = page_index & ~mask;
-               end_index = start_index | mask;
-               if (end_index > file_end)
-                       end_index = file_end;
-               actor_pages = end_index - start_index + 1;
-       }
+       if (end_index > file_end)
+               end_index = file_end;
+       actor_pages = end_index - start_index + 1;
 
        actor = actor_from_page_cache(actor_pages, target_page,
                                      readahead_pages, nr_pages, start_index,