From 6f09ffb1f4fadf156d5d1032217b9d1fa4e07dbe Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Mon, 19 Aug 2024 00:58:45 +0100 Subject: [PATCH] Squashfs: Update squashfs_readahead() to not use page->index This commit removes references to page->index in the pages returned from __readahead_batch(), and instead uses the 'start' variable. This does reveal a bug in the previous code in that 'start' was not updated every time around the loop. This is fixed in this commit. Signed-off-by: Phillip Lougher Link: https://lore.kernel.org/r/20240818235847.170468-3-phillip@squashfs.org.uk Signed-off-by: Christian Brauner --- fs/squashfs/file.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index 2b6b63f4ccd1a..50fe5a078b831 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -551,7 +551,6 @@ static void squashfs_readahead(struct readahead_control *ractl) return; for (;;) { - pgoff_t index; int res, bsize; u64 block = 0; unsigned int expected; @@ -570,13 +569,8 @@ static void squashfs_readahead(struct readahead_control *ractl) if (readahead_pos(ractl) >= i_size_read(inode)) goto skip_pages; - index = pages[0]->index >> shift; - - if ((pages[nr_pages - 1]->index >> shift) != index) - goto skip_pages; - - if (index == file_end && squashfs_i(inode)->fragment_block != - SQUASHFS_INVALID_BLK) { + if (start >> msblk->block_log == file_end && + squashfs_i(inode)->fragment_block != SQUASHFS_INVALID_BLK) { res = squashfs_readahead_fragment(pages, nr_pages, expected); if (res) @@ -584,7 +578,7 @@ static void squashfs_readahead(struct readahead_control *ractl) continue; } - bsize = read_blocklist(inode, index, &block); + bsize = read_blocklist(inode, start >> msblk->block_log, &block); if (bsize == 0) goto skip_pages; @@ -602,7 +596,7 @@ static void squashfs_readahead(struct readahead_control *ractl) /* Last page (if present) may have trailing bytes not filled */ bytes = res % PAGE_SIZE; - if (index == file_end && bytes && last_page) + if (start >> msblk->block_log == file_end && bytes && last_page) memzero_page(last_page, bytes, PAGE_SIZE - bytes); @@ -616,6 +610,8 @@ static void squashfs_readahead(struct readahead_control *ractl) unlock_page(pages[i]); put_page(pages[i]); } + + start += readahead_batch_length(ractl); } kfree(pages);