From f26044c83e6e473a61917f5db411d1417327d425 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 20 Aug 2020 17:42:21 -0700 Subject: squashfs: avoid bio_alloc() failure with 1Mbyte blocks This is a regression introduced by the patch "migrate from ll_rw_block usage to BIO". Bio_alloc() is limited to 256 pages (1 Mbyte). This can cause a failure when reading 1 Mbyte block filesystems. The problem is a datablock can be fully (or almost uncompressed), requiring 256 pages, but, because blocks are not aligned to page boundaries, it may require 257 pages to read. Bio_kmalloc() can handle 1024 pages, and so use this for the edge condition. Fixes: 93e72b3c612a ("squashfs: migrate from ll_rw_block usage to BIO") Reported-by: Nicolas Prochazka Reported-by: Tomoatsu Shimada Signed-off-by: Phillip Lougher Signed-off-by: Andrew Morton Reviewed-by: Guenter Roeck Cc: Philippe Liard Cc: Christoph Hellwig Cc: Adrien Schildknecht Cc: Daniel Rosenberg Cc: Link: http://lkml.kernel.org/r/20200815035637.15319-1-phillip@squashfs.org.uk Signed-off-by: Linus Torvalds --- fs/squashfs/block.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'fs/squashfs/block.c') diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index 76bb1c846845..8a19773b5a0b 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -87,7 +87,11 @@ static int squashfs_bio_read(struct super_block *sb, u64 index, int length, int error, i; struct bio *bio; - bio = bio_alloc(GFP_NOIO, page_count); + if (page_count <= BIO_MAX_PAGES) + bio = bio_alloc(GFP_NOIO, page_count); + else + bio = bio_kmalloc(GFP_NOIO, page_count); + if (!bio) return -ENOMEM; -- cgit v1.2.3-59-g8ed1b