diff options
| -rw-r--r-- | fs/squashfs/file_direct.c | 75 |
1 files changed, 12 insertions, 63 deletions
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c index 5af5802f5626..be4b12d31e0c 100644 --- a/fs/squashfs/file_direct.c +++ b/fs/squashfs/file_direct.c @@ -18,9 +18,6 @@ #include "squashfs.h" #include "page_actor.h" -static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, - int pages, struct page **page, int bytes); - /* Read separately compressed datablock directly into page cache */ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize, int expected) @@ -33,7 +30,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize, int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; int start_index = target_page->index & ~mask; int end_index = start_index | mask; - int i, n, pages, missing_pages, bytes, res = -ENOMEM; + int i, n, pages, bytes, res = -ENOMEM; struct page **page; struct squashfs_page_actor *actor; void *pageaddr; @@ -48,44 +45,29 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize, return res; /* Try to grab all the pages covered by the Squashfs block */ - for (missing_pages = 0, i = 0, n = start_index; i < pages; i++, n++) { + for (i = 0, n = start_index; n <= end_index; n++) { page[i] = (n == target_page->index) ? target_page : grab_cache_page_nowait(target_page->mapping, n); - if (page[i] == NULL) { - missing_pages++; + if (page[i] == NULL) continue; - } if (PageUptodate(page[i])) { unlock_page(page[i]); put_page(page[i]); - page[i] = NULL; - missing_pages++; + continue; } - } - - if (missing_pages) { - /* - * Couldn't get one or more pages, this page has either - * been VM reclaimed, but others are still in the page cache - * and uptodate, or we're racing with another thread in - * squashfs_readpage also trying to grab them. Fall back to - * using an intermediate buffer. - */ - res = squashfs_read_cache(target_page, block, bsize, pages, - page, expected); - if (res < 0) - goto mark_errored; - goto out; + i++; } + pages = i; + /* * Create a "page actor" which will kmap and kunmap the * page cache pages appropriately within the decompressor */ - actor = squashfs_page_actor_init_special(msblk, page, pages, 0); + actor = squashfs_page_actor_init_special(msblk, page, pages, expected); if (actor == NULL) goto out; @@ -102,12 +84,12 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize, goto mark_errored; } - /* Last page may have trailing bytes not filled */ + /* Last page (if present) may have trailing bytes not filled */ bytes = res % PAGE_SIZE; - if (bytes) { - pageaddr = kmap_atomic(page[pages - 1]); + if (page[pages - 1]->index == end_index && bytes) { + pageaddr = kmap_local_page(page[pages - 1]); memset(pageaddr + bytes, 0, PAGE_SIZE - bytes); - kunmap_atomic(pageaddr); + kunmap_local(pageaddr); } /* Mark pages as uptodate, unlock and release */ @@ -140,36 +122,3 @@ out: kfree(page); return res; } - - -static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, - int pages, struct page **page, int bytes) -{ - struct inode *i = target_page->mapping->host; - struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb, - block, bsize); - int res = buffer->error, n, offset = 0; - - if (res) { - ERROR("Unable to read page, block %llx, size %x\n", block, - bsize); - goto out; - } - - for (n = 0; n < pages && bytes > 0; n++, - bytes -= PAGE_SIZE, offset += PAGE_SIZE) { - int avail = min_t(int, bytes, PAGE_SIZE); - - if (page[n] == NULL) - continue; - - squashfs_fill_page(page[n], buffer, offset, avail); - unlock_page(page[n]); - if (page[n] != target_page) - put_page(page[n]); - } - -out: - squashfs_cache_put(buffer); - return res; -} |