* [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro()
@ 2018-01-11 13:09 Ilya Dryomov
2018-01-11 13:09 ` [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions Ilya Dryomov
` (3 more replies)
0 siblings, 4 replies; 7+ messages in thread
From: Ilya Dryomov @ 2018-01-11 13:09 UTC (permalink / raw)
To: linux-block
Cc: Jens Axboe, Christoph Hellwig, Tejun Heo, David Disseldorp,
Sagi Grimberg
Hello,
I was doing some cleanup work on rbd BLKROSET handler and discovered
that we ignore partition rw/ro setting (hd_struct->policy) for pretty
much everything but straight writes.
David (CCed) has blktests patches standing by.
(Another aspect of this is that we don't enforce open(2) mode. Tejun
took a stab at this a few years ago, but his patch had to be reverted:
75f1dc0d076d ("block: check bdev_read_only() from blkdev_get()")
e51900f7d38c ("block: revert block_dev read-only check")
It is a separate issue and refusing writes to read-only devices is
obviously more important, but perhaps it's time to revisit that as
well?)
v2 -> v3:
- lookup part only once; combine read-only check with existing
should_fail_request check
v1 -> v2:
- added unlikely() per Sagi's suggestion
Thanks,
Ilya
Ilya Dryomov (2):
block: fail op_is_write() requests to read-only partitions
block: add bdev_read_only() checks to common helpers
block/blk-core.c | 56 ++++++++++++++++++++++++++++++++++++++------------------
block/blk-lib.c | 12 ++++++++++++
2 files changed, 50 insertions(+), 18 deletions(-)
--
2.4.3
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions
2018-01-11 13:09 [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
@ 2018-01-11 13:09 ` Ilya Dryomov
2018-01-14 9:35 ` Sagi Grimberg
2018-01-11 13:09 ` [PATCH v3 2/2] block: add bdev_read_only() checks to common helpers Ilya Dryomov
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: Ilya Dryomov @ 2018-01-11 13:09 UTC (permalink / raw)
To: linux-block
Cc: Jens Axboe, Christoph Hellwig, Tejun Heo, David Disseldorp,
Sagi Grimberg
Regular block device writes go through blkdev_write_iter(), which does
bdev_read_only(), while zeroout/discard/etc requests are never checked,
both userspace- and kernel-triggered. Add a generic catch-all check to
generic_make_request_checks() to actually enforce ioctl(BLKROSET) and
set_disk_ro(), which is used by quite a few drivers for things like
snapshots, read-only backing files/images, etc.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
block/blk-core.c | 56 ++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 38 insertions(+), 18 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index f843ae4f858d..44a6dfe47ae1 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2062,6 +2062,21 @@ static inline bool should_fail_request(struct hd_struct *part,
#endif /* CONFIG_FAIL_MAKE_REQUEST */
+static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
+{
+ if (part->policy && op_is_write(bio_op(bio))) {
+ char b[BDEVNAME_SIZE];
+
+ printk(KERN_ERR
+ "generic_make_request: Trying to write "
+ "to read-only block-device %s (partno %d)\n",
+ bio_devname(bio, b), part->partno);
+ return true;
+ }
+
+ return false;
+}
+
/*
* Remap block n of partition p to block n+start(p) of the disk.
*/
@@ -2070,27 +2085,28 @@ static inline int blk_partition_remap(struct bio *bio)
struct hd_struct *p;
int ret = 0;
+ rcu_read_lock();
+ p = __disk_get_part(bio->bi_disk, bio->bi_partno);
+ if (unlikely(!p || should_fail_request(p, bio->bi_iter.bi_size) ||
+ bio_check_ro(bio, p))) {
+ ret = -EIO;
+ goto out;
+ }
+
/*
* Zone reset does not include bi_size so bio_sectors() is always 0.
* Include a test for the reset op code and perform the remap if needed.
*/
- if (!bio->bi_partno ||
- (!bio_sectors(bio) && bio_op(bio) != REQ_OP_ZONE_RESET))
- return 0;
+ if (!bio_sectors(bio) && bio_op(bio) != REQ_OP_ZONE_RESET)
+ goto out;
- rcu_read_lock();
- p = __disk_get_part(bio->bi_disk, bio->bi_partno);
- if (likely(p && !should_fail_request(p, bio->bi_iter.bi_size))) {
- bio->bi_iter.bi_sector += p->start_sect;
- bio->bi_partno = 0;
- trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
- bio->bi_iter.bi_sector - p->start_sect);
- } else {
- printk("%s: fail for partition %d\n", __func__, bio->bi_partno);
- ret = -EIO;
- }
- rcu_read_unlock();
+ bio->bi_iter.bi_sector += p->start_sect;
+ bio->bi_partno = 0;
+ trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
+ bio->bi_iter.bi_sector - p->start_sect);
+out:
+ rcu_read_unlock();
return ret;
}
@@ -2149,15 +2165,19 @@ generic_make_request_checks(struct bio *bio)
* For a REQ_NOWAIT based request, return -EOPNOTSUPP
* if queue is not a request based queue.
*/
-
if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_rq_based(q))
goto not_supported;
if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size))
goto end_io;
- if (blk_partition_remap(bio))
- goto end_io;
+ if (!bio->bi_partno) {
+ if (unlikely(bio_check_ro(bio, &bio->bi_disk->part0)))
+ goto end_io;
+ } else {
+ if (blk_partition_remap(bio))
+ goto end_io;
+ }
if (bio_check_eod(bio, nr_sectors))
goto end_io;
--
2.4.3
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v3 2/2] block: add bdev_read_only() checks to common helpers
2018-01-11 13:09 [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
2018-01-11 13:09 ` [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions Ilya Dryomov
@ 2018-01-11 13:09 ` Ilya Dryomov
2018-01-14 9:35 ` Sagi Grimberg
2018-01-18 11:16 ` [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
2018-01-18 19:57 ` Jens Axboe
3 siblings, 1 reply; 7+ messages in thread
From: Ilya Dryomov @ 2018-01-11 13:09 UTC (permalink / raw)
To: linux-block
Cc: Jens Axboe, Christoph Hellwig, Tejun Heo, David Disseldorp,
Sagi Grimberg
Similar to blkdev_write_iter(), return -EPERM if the partition is
read-only. This covers ioctl(), fallocate() and most in-kernel users
but isn't meant to be exhaustive -- everything else will be caught in
generic_make_request_checks(), fail with -EIO and can be fixed later.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
block/blk-lib.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 2bc544ce3d2e..a676084d4740 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -37,6 +37,9 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
if (!q)
return -ENXIO;
+ if (bdev_read_only(bdev))
+ return -EPERM;
+
if (flags & BLKDEV_DISCARD_SECURE) {
if (!blk_queue_secure_erase(q))
return -EOPNOTSUPP;
@@ -156,6 +159,9 @@ static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
if (!q)
return -ENXIO;
+ if (bdev_read_only(bdev))
+ return -EPERM;
+
bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
if ((sector | nr_sects) & bs_mask)
return -EINVAL;
@@ -233,6 +239,9 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev,
if (!q)
return -ENXIO;
+ if (bdev_read_only(bdev))
+ return -EPERM;
+
/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
@@ -287,6 +296,9 @@ static int __blkdev_issue_zero_pages(struct block_device *bdev,
if (!q)
return -ENXIO;
+ if (bdev_read_only(bdev))
+ return -EPERM;
+
while (nr_sects != 0) {
bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
gfp_mask);
--
2.4.3
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions
2018-01-11 13:09 ` [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions Ilya Dryomov
@ 2018-01-14 9:35 ` Sagi Grimberg
0 siblings, 0 replies; 7+ messages in thread
From: Sagi Grimberg @ 2018-01-14 9:35 UTC (permalink / raw)
To: Ilya Dryomov, linux-block
Cc: Jens Axboe, Christoph Hellwig, Tejun Heo, David Disseldorp
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 2/2] block: add bdev_read_only() checks to common helpers
2018-01-11 13:09 ` [PATCH v3 2/2] block: add bdev_read_only() checks to common helpers Ilya Dryomov
@ 2018-01-14 9:35 ` Sagi Grimberg
0 siblings, 0 replies; 7+ messages in thread
From: Sagi Grimberg @ 2018-01-14 9:35 UTC (permalink / raw)
To: Ilya Dryomov, linux-block
Cc: Jens Axboe, Christoph Hellwig, Tejun Heo, David Disseldorp
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro()
2018-01-11 13:09 [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
2018-01-11 13:09 ` [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions Ilya Dryomov
2018-01-11 13:09 ` [PATCH v3 2/2] block: add bdev_read_only() checks to common helpers Ilya Dryomov
@ 2018-01-18 11:16 ` Ilya Dryomov
2018-01-18 19:57 ` Jens Axboe
3 siblings, 0 replies; 7+ messages in thread
From: Ilya Dryomov @ 2018-01-18 11:16 UTC (permalink / raw)
To: Jens Axboe
Cc: linux-block, Christoph Hellwig, Tejun Heo, David Disseldorp,
Sagi Grimberg
On Thu, Jan 11, 2018 at 2:09 PM, Ilya Dryomov <idryomov@gmail.com> wrote:
> Hello,
>
> I was doing some cleanup work on rbd BLKROSET handler and discovered
> that we ignore partition rw/ro setting (hd_struct->policy) for pretty
> much everything but straight writes.
>
> David (CCed) has blktests patches standing by.
>
> (Another aspect of this is that we don't enforce open(2) mode. Tejun
> took a stab at this a few years ago, but his patch had to be reverted:
>
> 75f1dc0d076d ("block: check bdev_read_only() from blkdev_get()")
> e51900f7d38c ("block: revert block_dev read-only check")
>
> It is a separate issue and refusing writes to read-only devices is
> obviously more important, but perhaps it's time to revisit that as
> well?)
>
> v2 -> v3:
> - lookup part only once; combine read-only check with existing
> should_fail_request check
>
> v1 -> v2:
> - added unlikely() per Sagi's suggestion
>
> Thanks,
>
> Ilya
>
>
> Ilya Dryomov (2):
> block: fail op_is_write() requests to read-only partitions
> block: add bdev_read_only() checks to common helpers
>
> block/blk-core.c | 56 ++++++++++++++++++++++++++++++++++++++------------------
> block/blk-lib.c | 12 ++++++++++++
> 2 files changed, 50 insertions(+), 18 deletions(-)
Jens, could you please pick these up for 4.16?
Thanks,
Ilya
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro()
2018-01-11 13:09 [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
` (2 preceding siblings ...)
2018-01-18 11:16 ` [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
@ 2018-01-18 19:57 ` Jens Axboe
3 siblings, 0 replies; 7+ messages in thread
From: Jens Axboe @ 2018-01-18 19:57 UTC (permalink / raw)
To: Ilya Dryomov, linux-block
Cc: Christoph Hellwig, Tejun Heo, David Disseldorp, Sagi Grimberg
On 1/11/18 6:09 AM, Ilya Dryomov wrote:
> Hello,
>
> I was doing some cleanup work on rbd BLKROSET handler and discovered
> that we ignore partition rw/ro setting (hd_struct->policy) for pretty
> much everything but straight writes.
>
> David (CCed) has blktests patches standing by.
>
> (Another aspect of this is that we don't enforce open(2) mode. Tejun
> took a stab at this a few years ago, but his patch had to be reverted:
>
> 75f1dc0d076d ("block: check bdev_read_only() from blkdev_get()")
> e51900f7d38c ("block: revert block_dev read-only check")
>
> It is a separate issue and refusing writes to read-only devices is
> obviously more important, but perhaps it's time to revisit that as
> well?)
Applied for 4.16, thanks.
--
Jens Axboe
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-01-18 19:57 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2018-01-11 13:09 [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
2018-01-11 13:09 ` [PATCH v3 1/2] block: fail op_is_write() requests to read-only partitions Ilya Dryomov
2018-01-14 9:35 ` Sagi Grimberg
2018-01-11 13:09 ` [PATCH v3 2/2] block: add bdev_read_only() checks to common helpers Ilya Dryomov
2018-01-14 9:35 ` Sagi Grimberg
2018-01-18 11:16 ` [PATCH v3 0/2] block: enforce ioctl(BLKROSET) and set_disk_ro() Ilya Dryomov
2018-01-18 19:57 ` Jens Axboe
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