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authorKent Overstreet <kent.overstreet@linux.dev>2023-08-13 14:26:35 -0400
committerJens Axboe <axboe@kernel.dk>2023-08-14 15:40:42 -0600
commit168145f617d57bf4e474901b7ffa869337a802e6 (patch)
tree74d8fbcb33a1654e81623c5f520e9a26eaa0f161 /block/bio.c
parent7ba3792718709d410be5d971732b9251cbda67b6 (diff)
block: Allow bio_iov_iter_get_pages() with bio->bi_bdev unset
bio_iov_iter_get_pages() trims the IO based on the block size of the block device the IO will be issued to. However, bcachefs is a multi device filesystem; when we're creating the bio we don't yet know which block device the bio will be submitted to - we have to handle the alignment checks elsewhere. Thus this is needed to avoid a null ptr deref. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Link: https://lore.kernel.org/r/20230813182636.2966159-3-kent.overstreet@linux.dev Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/block/bio.c b/block/bio.c
index bb3ea4e05d4c..be484d87142b 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1231,7 +1231,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
struct page **pages = (struct page **)bv;
ssize_t size, left;
unsigned len, i = 0;
- size_t offset, trim;
+ size_t offset;
int ret = 0;
/*
@@ -1260,10 +1260,12 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE);
- trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1);
- iov_iter_revert(iter, trim);
+ if (bio->bi_bdev) {
+ size_t trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1);
+ iov_iter_revert(iter, trim);
+ size -= trim;
+ }
- size -= trim;
if (unlikely(!size)) {
ret = -EFAULT;
goto out;