diff options
| -rw-r--r-- | drivers/block/loop.c | 49 | ||||
| -rw-r--r-- | include/linux/loop.h | 1 |
2 files changed, 46 insertions, 4 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 936cac3c3126..b336433f8157 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -724,7 +724,7 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, goto out_putf; fput(old_file); - if (max_part > 0) + if (lo->lo_flags & LO_FLAGS_PARTSCAN) ioctl_by_bdev(bdev, BLKRRPART, 0); return 0; @@ -808,16 +808,25 @@ static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) return sprintf(buf, "%s\n", autoclear ? "1" : "0"); } +static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) +{ + int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); + + return sprintf(buf, "%s\n", partscan ? "1" : "0"); +} + LOOP_ATTR_RO(backing_file); LOOP_ATTR_RO(offset); LOOP_ATTR_RO(sizelimit); LOOP_ATTR_RO(autoclear); +LOOP_ATTR_RO(partscan); static struct attribute *loop_attrs[] = { &loop_attr_backing_file.attr, &loop_attr_offset.attr, &loop_attr_sizelimit.attr, &loop_attr_autoclear.attr, + &loop_attr_partscan.attr, NULL, }; @@ -979,7 +988,9 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, } lo->lo_state = Lo_bound; wake_up_process(lo->lo_thread); - if (max_part > 0) + if (part_shift) + lo->lo_flags |= LO_FLAGS_PARTSCAN; + if (lo->lo_flags & LO_FLAGS_PARTSCAN) ioctl_by_bdev(bdev, BLKRRPART, 0); return 0; @@ -1070,7 +1081,6 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) lo->lo_offset = 0; lo->lo_sizelimit = 0; lo->lo_encrypt_key_size = 0; - lo->lo_flags = 0; lo->lo_thread = NULL; memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); @@ -1088,8 +1098,11 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) lo->lo_state = Lo_unbound; /* This is safe: open() is still holding a reference. */ module_put(THIS_MODULE); - if (max_part > 0 && bdev) + if (lo->lo_flags & LO_FLAGS_PARTSCAN && bdev) ioctl_by_bdev(bdev, BLKRRPART, 0); + lo->lo_flags = 0; + if (!part_shift) + lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; mutex_unlock(&lo->lo_ctl_mutex); /* * Need not hold lo_ctl_mutex to fput backing file. @@ -1159,6 +1172,13 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) (info->lo_flags & LO_FLAGS_AUTOCLEAR)) lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; + if ((info->lo_flags & LO_FLAGS_PARTSCAN) && + !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { + lo->lo_flags |= LO_FLAGS_PARTSCAN; + lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; + ioctl_by_bdev(lo->lo_device, BLKRRPART, 0); + } + lo->lo_encrypt_key_size = info->lo_encrypt_key_size; lo->lo_init[0] = info->lo_init[0]; lo->lo_init[1] = info->lo_init[1]; @@ -1654,6 +1674,27 @@ static struct loop_device *loop_alloc(int i) if (!disk) goto out_free_queue; + /* + * Disable partition scanning by default. The in-kernel partition + * scanning can be requested individually per-device during its + * setup. Userspace can always add and remove partitions from all + * devices. The needed partition minors are allocated from the + * extended minor space, the main loop device numbers will continue + * to match the loop minors, regardless of the number of partitions + * used. + * + * If max_part is given, partition scanning is globally enabled for + * all loop devices. The minors for the main loop devices will be + * multiples of max_part. + * + * Note: Global-for-all-devices, set-only-at-init, read-only module + * parameteters like 'max_loop' and 'max_part' make things needlessly + * complicated, are too static, inflexible and may surprise + * userspace tools. Parameters like this in general should be avoided. + */ + if (!part_shift) + disk->flags |= GENHD_FL_NO_PART_SCAN; + disk->flags |= GENHD_FL_EXT_DEVT; mutex_init(&lo->lo_ctl_mutex); lo->lo_number = i; lo->lo_thread = NULL; diff --git a/include/linux/loop.h b/include/linux/loop.h index 66c194e2d9b9..4367fc507fe9 100644 --- a/include/linux/loop.h +++ b/include/linux/loop.h @@ -76,6 +76,7 @@ enum { LO_FLAGS_READ_ONLY = 1, LO_FLAGS_USE_AOPS = 2, LO_FLAGS_AUTOCLEAR = 4, + LO_FLAGS_PARTSCAN = 8, }; #include <asm/posix_types.h> /* for __kernel_old_dev_t */ |