This patch fixes I/O errors during BLKRRPART ioctl() behavior right
after format operation that changed logical block size of the block
device with a same file descriptor opened.
This issue can be easily reproduced with a single format command in case
of NVMe (logical block size 512B to 4096B).
nvme format /dev/nvme0n1 --lbaf=1 --force
This is because the application, nvme-cli format subcommand issues an
admin command followed by BLKRRPART ioctl to re-read partition
information without closing the file descriptor. If file descriptor
stays opened, __blkdev_get() will not be invoked at all even logical
block size has been changed.
It will cause I/O errors with invalid Read operations during the
BLKRRPART ioctl due to i_blkbits mismatch. The invalid operations in
BLKRRPART happens with under-flowed Number of LBA(NLB) values
0xffff(65535) because i_blkbits is still set to 9 even the logical block
size has been updated to 4096. The BLKRRPART will lead buffer_head to
hold 512B data which is less than the logical lock size of the block
device.
The root cause, which is because i_blkbits of inode of the block device
is not updated, can be solved easily by re-opening file descriptor
again from application. But, that's just for application's business
and kernel should reject invalid Read operations during the BLKRRPART
ioctl.
This patch rejects I/O from the path of add_partitions() to avoid
issuing invalid Read operations to device. It sets a flag to
request_queue in blk_queue_logical_block_size to minimize caller-side
updates.
Signed-off-by: Minwoo Im <minwoo.im.dev@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-settings.c | 3 +++
block/partitions/core.c | 12 ++++++++++++
fs/block_dev.c | 8 ++++++++
include/linux/blkdev.h | 1 +
4 files changed, 24 insertions(+)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 4c974340f1a9..5b1e0bf54d7e 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -329,6 +329,9 @@ void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
{
struct queue_limits *limits = &q->limits;
+ if (limits->logical_block_size != size)
+ blk_queue_flag_set(QUEUE_FLAG_LBSZ_CHANGED, q);
+
limits->logical_block_size = size;
if (limits->physical_block_size < size)
diff --git a/block/partitions/core.c b/block/partitions/core.c
index b1cdf88f96e2..092d6712c7fc 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -601,12 +601,24 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
{
+ struct request_queue *q = bdev_get_queue(bdev);
struct parsed_partitions *state;
int ret = -EAGAIN, p;
if (!disk_part_scan_enabled(disk))
return 0;
+ /*
+ * Reject to check partition information if block size has been changed
+ * in the runtime. If block size of a block device has been changed,
+ * the file descriptor should be opened agian to update the blkbits.
+ */
+ if (test_bit(QUEUE_FLAG_LBSZ_CHANGED, &q->queue_flags)) {
+ pr_warn("%s: rejecting checking partition. fd should be opened again.\n",
+ disk->disk_name);
+ return -EBADFD;
+ }
+
state = check_partition(disk, bdev);
if (!state)
return 0;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 6f5bd9950baf..8555308c503d 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -130,7 +130,15 @@ EXPORT_SYMBOL(truncate_bdev_range);
static void set_init_blocksize(struct block_device *bdev)
{
+ struct request_queue *q = bdev_get_queue(bdev);
+
bdev->bd_inode->i_blkbits = blksize_bits(bdev_logical_block_size(bdev));
+
+ /*
+ * Allow I/O commands for this block device. We can say that this
+ * block device has proper blkbits updated.
+ */
+ blk_queue_flag_clear(QUEUE_FLAG_LBSZ_CHANGED, q);
}
int set_blocksize(struct block_device *bdev, int size)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 20f3706b6b2e..f725e933db40 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -621,6 +621,7 @@ struct request_queue {
#define QUEUE_FLAG_RQ_ALLOC_TIME 27 /* record rq->alloc_time_ns */
#define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */
#define QUEUE_FLAG_NOWAIT 29 /* device supports NOWAIT */
+#define QUEUE_FLAG_LBSZ_CHANGED 30 /* logical block size changed */
#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
(1 << QUEUE_FLAG_SAME_COMP) | \
--
2.17.1
