On Wed, 1 Jul 2015, Mike Snitzer wrote: > bio_integrity_alloc() and bio_integrity_free() assume that if a bio was > allocated from a bioset that that bioset also had its bio_integrity_pool > allocated using bioset_integrity_create(). This is a very bad > assumption given that bioset_create() and bioset_integrity_create() are > completely disjoint. Not all callers of bioset_create() have been > trained to also call bioset_integrity_create() -- and they may not care > to be. > > Fix this by falling back to kmalloc'ing 'struct bio_integrity_payload' > rather than force all bioset consumers to (wastefully) preallocate a > bio_integrity_pool that they very likely won't actually need (given the > niche nature of the current block integrity support). > > Otherwise, a NULL pointer "Kernel BUG" with a trace like the following > will be observed (as seen on s390x using zfcp storage) because dm-io > doesn't use bioset_integrity_create() when creating its bioset: > > [ 791.643338] Call Trace: > [ 791.643339] ([<00000003df98b848>] 0x3df98b848) > [ 791.643341] [<00000000002c5de8>] bio_integrity_alloc+0x48/0xf8 > [ 791.643348] [<00000000002c6486>] bio_integrity_prep+0xae/0x2f0 > [ 791.643349] [<0000000000371e38>] blk_queue_bio+0x1c8/0x3d8 > [ 791.643355] [<000000000036f8d0>] generic_make_request+0xc0/0x100 > [ 791.643357] [<000000000036f9b2>] submit_bio+0xa2/0x198 > [ 791.643406] [<000003ff801f9774>] dispatch_io+0x15c/0x3b0 [dm_mod] > [ 791.643419] [<000003ff801f9b3e>] dm_io+0x176/0x2f0 [dm_mod] > [ 791.643423] [<000003ff8074b28a>] do_reads+0x13a/0x1a8 [dm_mirror] > [ 791.643425] [<000003ff8074b43a>] do_mirror+0x142/0x298 [dm_mirror] > [ 791.643428] [<0000000000154fca>] process_one_work+0x18a/0x3f8 > [ 791.643432] [<000000000015598a>] worker_thread+0x132/0x3b0 > [ 791.643435] [<000000000015d49a>] kthread+0xd2/0xd8 > [ 791.643438] [<00000000005bc0ca>] kernel_thread_starter+0x6/0xc > [ 791.643446] [<00000000005bc0c4>] kernel_thread_starter+0x0/0xc > > Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Acked-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > --- > block/bio-integrity.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > NOTE: this serves as a more generic fix in the block layer rather than > the dm-io specific fix which isn't ideal (due to potential for memory > waste), see: > https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=17dbe96d4f8a6f87004e6cfb5944872dfe2edb9f > > diff --git a/block/bio-integrity.c b/block/bio-integrity.c > index 0436c21..719b715 100644 > --- a/block/bio-integrity.c > +++ b/block/bio-integrity.c > @@ -51,7 +51,7 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, > unsigned long idx = BIO_POOL_NONE; > unsigned inline_vecs; > > - if (!bs) { > + if (!bs || !bs->bio_integrity_pool) { > bip = kmalloc(sizeof(struct bio_integrity_payload) + > sizeof(struct bio_vec) * nr_vecs, gfp_mask); > inline_vecs = nr_vecs; > @@ -104,7 +104,7 @@ void bio_integrity_free(struct bio *bio) > kfree(page_address(bip->bip_vec->bv_page) + > bip->bip_vec->bv_offset); > > - if (bs) { > + if (bs && bs->bio_integrity_pool) { > if (bip->bip_slab != BIO_POOL_NONE) > bvec_free(bs->bvec_integrity_pool, bip->bip_vec, > bip->bip_slab); > -- > 2.3.2 (Apple Git-55) > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
