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authorPhillip Lougher <phillip@squashfs.org.uk>2020-08-20 17:42:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-21 09:52:53 -0700
commitf26044c83e6e473a61917f5db411d1417327d425 (patch)
tree400f1759ff82a27f24e282f67d4ed44ca84eab09
parentc17c3dc9d08b9aad9a55a1e53f205187972f448e (diff)
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 <nicolas.prochazka@gmail.com> Reported-by: Tomoatsu Shimada <shimada@walbrix.com> Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Cc: Philippe Liard <pliard@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Adrien Schildknecht <adrien+dev@schischi.me> Cc: Daniel Rosenberg <drosen@google.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200815035637.15319-1-phillip@squashfs.org.uk Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/squashfs/block.c6
1 files changed, 5 insertions, 1 deletions
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;