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| author | Mikulas Patocka <mpatocka@redhat.com> | 2016-08-30 16:38:42 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-24 10:07:41 +0200 |
| commit | 2ab3ad1db7fa2fd07972d11b34c586ac13a4f59a (patch) | |
| tree | 2f36e586a78727914102b9421a93299fbbdb38df /drivers/md | |
| parent | 319930894f3614de9dabd1e4fae34328d4274a6e (diff) | |
| download | lwn-2ab3ad1db7fa2fd07972d11b34c586ac13a4f59a.tar.gz lwn-2ab3ad1db7fa2fd07972d11b34c586ac13a4f59a.zip | |
dm crypt: fix error with too large bios
commit 4e870e948fbabf62b78e8410f04c67703e7c816b upstream.
When dm-crypt processes writes, it allocates a new bio in
crypt_alloc_buffer(). The bio is allocated from a bio set and it can
have at most BIO_MAX_PAGES vector entries, however the incoming bio can be
larger (e.g. if it was allocated by bcache). If the incoming bio is
larger, bio_alloc_bioset() fails and an error is returned.
To avoid the error, we test for a too large bio in the function
crypt_map() and use dm_accept_partial_bio() to split the bio.
dm_accept_partial_bio() trims the current bio to the desired size and
asks DM core to send another bio with the rest of the data.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-crypt.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 3147c8d09ea8..51eda7235e32 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1920,6 +1920,13 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) return DM_MAPIO_REMAPPED; } + /* + * Check if bio is too large, split as needed. + */ + if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && + bio_data_dir(bio) == WRITE) + dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); + io = dm_per_bio_data(bio, cc->per_bio_data_size); crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); io->ctx.req = (struct ablkcipher_request *)(io + 1); |