diff options
Diffstat (limited to 'fs/squashfs/file.c')
-rw-r--r-- | fs/squashfs/file.c | 140 |
1 files changed, 105 insertions, 35 deletions
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index e5c9689062ba..d778763de26e 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -47,12 +47,16 @@ #include <linux/string.h> #include <linux/pagemap.h> #include <linux/mutex.h> +#include <linux/mm_inline.h> #include "squashfs_fs.h" #include "squashfs_fs_sb.h" #include "squashfs_fs_i.h" #include "squashfs.h" +// Backported from 4.5 +#define lru_to_page(head) (list_entry((head)->prev, struct page, lru)) + /* * Locate cache slot in range [offset, index] for specified inode. If * there's more than one return the slot closest to index. @@ -438,6 +442,21 @@ static int squashfs_readpage_fragment(struct page *page) return res; } +static int squashfs_readpages_fragment(struct page *page, + struct list_head *readahead_pages, struct address_space *mapping) +{ + if (!page) { + page = lru_to_page(readahead_pages); + list_del(&page->lru); + if (add_to_page_cache_lru(page, mapping, page->index, + GFP_KERNEL)) { + put_page(page); + return 0; + } + } + return squashfs_readpage_fragment(page); +} + static int squashfs_readpage_sparse(struct page *page, int index, int file_end) { struct inode *inode = page->mapping->host; @@ -450,54 +469,105 @@ static int squashfs_readpage_sparse(struct page *page, int index, int file_end) return 0; } -static int squashfs_readpage(struct file *file, struct page *page) +static int squashfs_readpages_sparse(struct page *page, + struct list_head *readahead_pages, int index, int file_end, + struct address_space *mapping) { - struct inode *inode = page->mapping->host; + if (!page) { + page = lru_to_page(readahead_pages); + list_del(&page->lru); + if (add_to_page_cache_lru(page, mapping, page->index, + GFP_KERNEL)) { + put_page(page); + return 0; + } + } + return squashfs_readpage_sparse(page, index, file_end); +} + +static int __squashfs_readpages(struct file *file, struct page *page, + struct list_head *readahead_pages, unsigned int nr_pages, + struct address_space *mapping) +{ + struct inode *inode = mapping->host; struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; - int index = page->index >> (msblk->block_log - PAGE_CACHE_SHIFT); int file_end = i_size_read(inode) >> msblk->block_log; int res; - void *pageaddr; - TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n", - page->index, squashfs_i(inode)->start); + do { + struct page *cur_page = page ? page + : lru_to_page(readahead_pages); + int page_index = cur_page->index; + int index = page_index >> (msblk->block_log - PAGE_CACHE_SHIFT); + + if (page_index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> + PAGE_CACHE_SHIFT)) + return 1; + + 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) + return -1; + + if (bsize == 0) { + res = squashfs_readpages_sparse(page, + readahead_pages, index, file_end, + mapping); + } else { + res = squashfs_readpages_block(page, + readahead_pages, &nr_pages, mapping, + page_index, block, bsize); + } + } else { + res = squashfs_readpages_fragment(page, + readahead_pages, mapping); + } + if (res) + return 0; + page = NULL; + } while (readahead_pages && !list_empty(readahead_pages)); - if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> - PAGE_CACHE_SHIFT)) - goto out; + return 0; +} - 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) - goto error_out; +static int squashfs_readpage(struct file *file, struct page *page) +{ + int ret; - if (bsize == 0) - res = squashfs_readpage_sparse(page, index, file_end); + TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n", + page->index, squashfs_i(page->mapping->host)->start); + + get_page(page); + + ret = __squashfs_readpages(file, page, NULL, 1, page->mapping); + if (ret) { + flush_dcache_page(page); + if (ret < 0) + SetPageError(page); else - res = squashfs_readpage_block(page, block, bsize); - } else - res = squashfs_readpage_fragment(page); - - if (!res) - return 0; - -error_out: - SetPageError(page); -out: - pageaddr = kmap_atomic(page); - memset(pageaddr, 0, PAGE_CACHE_SIZE); - kunmap_atomic(pageaddr); - flush_dcache_page(page); - if (!PageError(page)) - SetPageUptodate(page); - unlock_page(page); + SetPageUptodate(page); + zero_user_segment(page, 0, PAGE_CACHE_SIZE); + unlock_page(page); + put_page(page); + } return 0; } +static int squashfs_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned int nr_pages) +{ + TRACE("Entered squashfs_readpages, %u pages, first page index %lx\n", + nr_pages, lru_to_page(pages)->index); + __squashfs_readpages(file, NULL, pages, nr_pages, mapping); + return 0; +} + const struct address_space_operations squashfs_aops = { - .readpage = squashfs_readpage + .readpage = squashfs_readpage, + .readpages = squashfs_readpages, }; |