| Message ID | 20230212092641.2394146-4-yukuai1@huaweicloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: fix scan partition for exclusively open device again | expand |
On Sun 12-02-23 17:26:41, Yu Kuai wrote: > From: Yu Kuai <yukuai3@huawei.com> > > As explained in commit 36369f46e917 ("block: Do not reread partition table > on exclusively open device"), reread partition on the device that is > exclusively opened by someone else is problematic. > > This patch will make sure partition scan will only be proceed if current > thread open the device exclusively, or the device is not opened > exclusively, and in the later case, other scanners and exclusive openers > will be blocked temporarily until partition scan is done. > > Fixes: 10c70d95c0f2 ("block: remove the bd_openers checks in blk_drop_partitions") > Cc: <stable@vger.kernel.org> > Suggested-by: Jan Kara <jack@suse.cz> > Signed-off-by: Yu Kuai <yukuai3@huawei.com> Just one nit below. > diff --git a/block/genhd.c b/block/genhd.c > index c0d1220bd798..6ec10ffeb9cc 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -359,6 +359,7 @@ EXPORT_SYMBOL_GPL(disk_uevent); > int disk_scan_partitions(struct gendisk *disk, fmode_t mode) > { > struct block_device *bdev; > + int ret = 0; > > if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN)) > return -EINVAL; > @@ -367,11 +368,29 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) > if (disk->open_partitions) > return -EBUSY; > > - bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL); > - if (IS_ERR(bdev)) > - return PTR_ERR(bdev); > + /* > + * If the device is opened exclusively by current thread already, it's > + * safe to scan partitons, otherwise, use bd_prepare_to_claim() to > + * synchronize with other exclusivet openers and other partition ^^^ typo here Honza
diff --git a/block/genhd.c b/block/genhd.c index c0d1220bd798..6ec10ffeb9cc 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -359,6 +359,7 @@ EXPORT_SYMBOL_GPL(disk_uevent); int disk_scan_partitions(struct gendisk *disk, fmode_t mode) { struct block_device *bdev; + int ret = 0; if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN)) return -EINVAL; @@ -367,11 +368,29 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) if (disk->open_partitions) return -EBUSY; - bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL); - if (IS_ERR(bdev)) - return PTR_ERR(bdev); + /* + * If the device is opened exclusively by current thread already, it's + * safe to scan partitons, otherwise, use bd_prepare_to_claim() to + * synchronize with other exclusivet openers and other partition + * scanners. + */ + if (!(mode & FMODE_EXCL)) { + ret = bd_prepare_to_claim(disk->part0, disk_scan_partitions); + if (ret) + return ret; + } + + bdev = blkdev_get_by_dev(disk_devt(disk), mode & ~FMODE_EXCL, NULL); + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); + goto out; + } blkdev_put(bdev, mode); - return 0; + +out: + if (!(mode & FMODE_EXCL)) + bd_abort_claiming(disk->part0, disk_scan_partitions); + return ret; } /** diff --git a/block/ioctl.c b/block/ioctl.c index 0eefcdb936a0..3adfdb904dd0 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -529,7 +529,7 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, if (bdev_is_partition(bdev)) return -EINVAL; set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); - return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL); + return disk_scan_partitions(bdev->bd_disk, mode); case BLKTRACESTART: case BLKTRACESTOP: case BLKTRACETEARDOWN: