diff options
| author |   Kent Overstreet <kent.overstreet@linux.dev> | 2023-08-13 14:26:35 -0400 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2023-08-14 15:40:42 -0600 |
| commit | 168145f617d57bf4e474901b7ffa869337a802e6 (patch) | |
| tree | 74d8fbcb33a1654e81623c5f520e9a26eaa0f161 /block/bio.c | |
| parent | block: Add some exports for bcachefs (diff) | |
| download | wireguard-linux-168145f617d57bf4e474901b7ffa869337a802e6.tar.xz wireguard-linux-168145f617d57bf4e474901b7ffa869337a802e6.zip | |
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.c | 10 |
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; |