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authorRatna Manoj Bolla <manoj.br@gmail.com>2017-03-24 14:08:29 -0400
committerJens Axboe <axboe@fb.com>2017-03-24 15:42:47 -0600
commitabbbdf12497d36b001e0865bc5bc6cc363f3a5e1 (patch)
treee0534687a8cf3b686bcff619320ec3258c8986bc /drivers/block/nbd.c
parentf8586855031a1d6b243f013c3082631346fddfad (diff)
downloadlwn-abbbdf12497d36b001e0865bc5bc6cc363f3a5e1.tar.gz
lwn-abbbdf12497d36b001e0865bc5bc6cc363f3a5e1.zip
nbd: replace kill_bdev() with __invalidate_device()
When a filesystem is mounted on a nbd device and on a disconnect, because of kill_bdev(), and resetting bdev size to zero, buffer_head mappings are getting destroyed under mounted filesystem. After a bdev size reset(i.e bdev->bd_inode->i_size = 0) on a disconnect, followed by a sys_umount(), generic_shutdown_super()->... ->__sync_blockdev()->... -blkdev_writepages()->... ->do_invalidatepage()->... -discard_buffer() is discarding superblock buffer_head assumed to be in mapped state by ext4_commit_super(). [mlin: ported to 4.11-rc2] Signed-off-by: Ratna Manoj Bolla <manoj.br@gmail.com Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/nbd.c')
-rw-r--r--drivers/block/nbd.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b0003dab90b9..d8a23561b4cb 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -126,7 +126,8 @@ static const char *nbdcmd_to_ascii(int cmd)
static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev)
{
- bd_set_size(bdev, 0);
+ if (bdev->bd_openers <= 1)
+ bd_set_size(bdev, 0);
set_capacity(nbd->disk, 0);
kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
@@ -665,6 +666,8 @@ static void nbd_reset(struct nbd_device *nbd)
static void nbd_bdev_reset(struct block_device *bdev)
{
+ if (bdev->bd_openers > 1)
+ return;
set_device_ro(bdev, false);
bdev->bd_inode->i_size = 0;
if (max_part > 0) {
@@ -728,7 +731,8 @@ static int nbd_clear_sock(struct nbd_device *nbd, struct block_device *bdev)
{
sock_shutdown(nbd);
nbd_clear_que(nbd);
- kill_bdev(bdev);
+
+ __invalidate_device(bdev, true);
nbd_bdev_reset(bdev);
/*
* We want to give the run thread a chance to wait for everybody