On 09/12/2017 03:22 PM, Javier González wrote:
On 10 Sep 2017, at 21.07, Rakesh Pandit <rakesh@xxxxxxxxxx> wrote: When a virtual block device is formatted and mounted after creating with "nvme lnvm create... -t pblk", a removal from "nvm lnvm remove" would result in this: 446416.309757] bdi-block not registered [446416.309773] ------------[ cut here ]------------ [446416.309780] WARNING: CPU: 3 PID: 4319 at fs/fs-writeback.c:2159 __mark_inode_dirty+0x268/0x340 Ideally removal should return -EBUSY as block device is mounted after formatting. This patch tries to address this checking if whole device or any partition of it already mounted or not before removal. Whole device is checked using "bd_super" member of block device. This member is always set once block device has been mounted using a filesystem. Another member "bd_part_count" takes care of checking any if any partitions are under use. "bd_part_count" is only updated under locks when partitions are opened or closed (first open and last release). This at least does take care sending -EBUSY if removal is being attempted while whole block device or any partition is mounted. Signed-off-by: Rakesh Pandit <rakesh@xxxxxxxxxx> --- V2: Take a different approach. Instead of checking bd_openers use bd_super and bd_part_count. This should address the removal of bdevs which are mounted from removal. drivers/lightnvm/core.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c index c39f87d..9f9a137 100644 --- a/drivers/lightnvm/core.c +++ b/drivers/lightnvm/core.c @@ -373,6 +373,7 @@ static void __nvm_remove_target(struct nvm_target *t) static int nvm_remove_tgt(struct nvm_dev *dev, struct nvm_ioctl_remove *remove) { struct nvm_target *t; + struct block_device *bdev; mutex_lock(&dev->mlock); t = nvm_find_target(dev, remove->tgtname); @@ -380,6 +381,19 @@ static int nvm_remove_tgt(struct nvm_dev *dev, struct nvm_ioctl_remove *remove) mutex_unlock(&dev->mlock); return 1; } + bdev = bdget_disk(t->disk, 0); + if (!bdev) { + pr_err("nvm: removal failed, allocating bd failed\n"); + mutex_unlock(&dev->mlock); + return -ENOMEM; + } + if (bdev->bd_super || bdev->bd_part_count) { + pr_err("nvm: removal failed, block device busy\n"); + bdput(bdev); + mutex_unlock(&dev->mlock); + return -EBUSY; + } + bdput(bdev); __nvm_remove_target(t); mutex_unlock(&dev->mlock); -- 2.7.4Looks good. Reviewed-by: Javier González <javier@xxxxxxxxxxxx>
Thanks Rakesh. I pulled it in for 4.15.
