This is a regression introduced by the "migrate from ll_rw_block usage
to BIO" patch.
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.
Reported-by: Nicolas Prochazka <nicolas.procha...@gmail.com>
Reported-by: Tomoatsu Shimada <shim...@walbrix.com>
Signed-off-by: Phillip Lougher <phil...@squashfs.org.uk>
---
fs/squashfs/block.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
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;
--
2.20.1
