Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Phillip Lougher <> | Subject | [PATCH] squashfs: avoid bio_alloc() failure with 1Mbyte blocks | Date | Sat, 15 Aug 2020 04:56:37 +0100 |
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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.prochazka@gmail.com> Reported-by: Tomoatsu Shimada <shimada@walbrix.com> Signed-off-by: Phillip Lougher <phillip@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
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