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To: Martijn Coenen , axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com Cc: narayan@google.com, zezeozue@google.com, kernel-team@android.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, maco@google.com, Chaitanya.Kulkarni@wdc.com, Jaegeuk Kim References: <20200420080409.111693-1-maco@android.com> <20200420080409.111693-2-maco@android.com> From: Bart Van Assche Message-ID: Date: Mon, 20 Apr 2020 06:22:12 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200420080409.111693-2-maco@android.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/20/20 1:04 AM, Martijn Coenen wrote: > +/** > + * loop_set_size - sets device size and notifies userspace > + * @lo: struct loop_device to set the size for > + * @size: new size of the loop device > + * > + * Callers must validate that the size passed into this function fits into > + * a sector_t. > + */ > +static void loop_set_size(struct loop_device *lo, loff_t size) > +{ > + struct block_device *bdev = lo->lo_device; > + > + set_capacity(lo->lo_disk, size); > + bd_set_size(bdev, size << 9); > + /* let user-space know about the new size */ > + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); > +} How about using the SECTOR_SHIFT constant instead of "9"? I think the following has been added recently in include/linux/blkdev.h: #define SECTOR_SHIFT 9 > @@ -1295,6 +1321,15 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > /* I/O need to be drained during transfer transition */ > blk_mq_freeze_queue(lo->lo_queue); > > + if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) { > + /* kill_bdev should have truncated all the pages */ > + err = -EAGAIN; > + pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", > + __func__, lo->lo_number, lo->lo_file_name, > + lo->lo_device->bd_inode->i_mapping->nrpages); > + goto out_unfreeze; > + } > + > err = loop_release_xfer(lo); > if (err) > goto out_unfreeze; Please Cc Jaegeuk for any changes in this code (see also https://lore.kernel.org/linux-block/20190518005304.GA19446@jaegeuk-macbookpro.roam.corp.google.com/). Please also change the "kill_bdev should have truncated all the pages" comment into something like "return -EAGAIN if any pages have been dirtied after kill_bdev() returned". Thanks, Bart.