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Thu, 28 Jan 2021 12:13:14 -0500 (EST) Received: from prgdevlinuxpatch01.amust.local (172.24.14.5) by prgmbx01.amust.local (172.24.0.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2; Thu, 28 Jan 2021 18:13:12 +0100 From: Sergei Shtepa To: , , , , , Date: Thu, 28 Jan 2021 20:12:35 +0300 Message-ID: <1611853955-32167-3-git-send-email-sergei.shtepa@veeam.com> In-Reply-To: <1611853955-32167-1-git-send-email-sergei.shtepa@veeam.com> References: <1611853955-32167-1-git-send-email-sergei.shtepa@veeam.com> MIME-Version: 1.0 X-Originating-IP: [172.24.14.5] X-ClientProxiedBy: prgmbx01.amust.local (172.24.0.171) To prgmbx01.amust.local (172.24.0.171) X-EsetResult: clean, is OK X-EsetId: 37303A29C604D265677D6B X-Veeam-MMEX: True X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-loop: dm-devel@redhat.com Cc: pavel.tide@veeam.com, sergei.shtepa@veeam.com Subject: [dm-devel] [PATCH 2/2] [dm] blk_interposer for dm-linear X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Implement a block interposer for device-mapper to attach to an existing block layer stack. Using the interposer, we can connect the dm-linear to a device with a mounted file system. changes: * the new dm_interposer structure contains blk_interposer to intercept bio from the interposed disk and interval tree of block devices on this disk. * the new interval tree for device mapper. * the dm_submit_bio_interposer_fn() function implements the bio interception logic. * the functions dm_interposer_attach_dev() & dm_interposer_detach_dev() allow to attach and detach devices to dm_interposer. * the new parameter 'noexcl' allows to create dm-linear to device with an already mounted file system. * the non_exclusive parameter in dm_target structure - it`s a sign that target device should be opened without FMODE_EXCL mode. * the new ioctl IOCTL_DEV_REMAP allow to attach dm device to a regular block device. Signed-off-by: Sergei Shtepa --- drivers/md/dm-core.h | 46 +++- drivers/md/dm-ioctl.c | 39 ++++ drivers/md/dm-linear.c | 17 +- drivers/md/dm-table.c | 12 +- drivers/md/dm.c | 383 ++++++++++++++++++++++++++++++++-- drivers/md/dm.h | 2 +- include/linux/device-mapper.h | 7 + include/uapi/linux/dm-ioctl.h | 15 +- 8 files changed, 493 insertions(+), 28 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 086d293c2b03..0f870b1d4be4 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -13,7 +13,7 @@ #include #include #include - +#include #include #include "dm.h" @@ -109,6 +109,9 @@ struct mapped_device { bool init_tio_pdu:1; struct srcu_struct io_barrier; + + /* interposer device for remap */ + struct dm_interposed_dev *ip_dev; }; void disable_discard(struct mapped_device *md); @@ -164,6 +167,47 @@ struct dm_table { struct dm_md_mempools *mempools; }; +/* + * Interval tree for device mapper + */ +struct dm_rb_range { + struct rb_node node; + sector_t start; /* start sector of rb node */ + sector_t last; /* end sector of rb node */ + sector_t _subtree_last; /* highest sector in subtree of rb node */ +}; + +void dm_rb_insert(struct dm_rb_range *node, struct rb_root_cached *root); +void dm_rb_remove(struct dm_rb_range *node, struct rb_root_cached *root); + +struct dm_rb_range *dm_rb_iter_first(struct rb_root_cached *root, sector_t start, sector_t last); +struct dm_rb_range *dm_rb_iter_next(struct dm_rb_range *node, sector_t start, sector_t last); + +/* + * For connecting blk_interposer and dm-targets devices. + */ +typedef void (*dm_interpose_bio_t) (void *context, struct dm_rb_range *node, struct bio *bio); + +struct dm_interposed_dev { + struct gendisk *disk; + struct dm_rb_range node; + void *context; + dm_interpose_bio_t dm_interpose_bio; + + atomic64_t ip_cnt; /*for debug purpose*/ +}; + +struct dm_interposed_dev *dm_interposer_new_dev(struct gendisk *disk, + sector_t ofs, sector_t len, + void *context, + dm_interpose_bio_t dm_interpose_bio_t); +void dm_interposer_free_dev(struct dm_interposed_dev *ip_dev); +int dm_interposer_attach_dev(struct dm_interposed_dev *ip_dev); +int dm_interposer_detach_dev(struct dm_interposed_dev *ip_dev); + +int dm_remap_install(struct mapped_device *md, const char *donor_device_name); +int dm_remap_uninstall(struct mapped_device *md); + static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) { return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 5e306bba4375..2944d442c256 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1649,6 +1649,44 @@ static int target_message(struct file *filp, struct dm_ioctl *param, size_t para return r; } +static inline int dev_remap_start(struct mapped_device *md, uint8_t *params) +{ + char *donor_device_name = (char *)params; + + return dm_remap_install(md, donor_device_name); +} +static int dev_remap_finish(struct mapped_device *md) +{ + return dm_remap_uninstall(md); +} + +static int dev_remap(struct file *filp, struct dm_ioctl *param, size_t param_size) +{ + int ret = 0; + struct mapped_device *md; + void *bin_data; + struct dm_remap_param *remap_param; + + md = find_device(param); + if (!md) + return -ENXIO; + + bin_data = (void *)(param) + param->data_start; + remap_param = bin_data; + + if (remap_param->cmd == REMAP_START_CMD) + ret = dev_remap_start(md, remap_param->params); + else if (remap_param->cmd == REMAP_FINISH_CMD) + ret = dev_remap_finish(md); + else { + DMWARN("Invalid remap command, %d", remap_param->cmd); + ret = -EINVAL; + } + + dm_put(md); + return ret; +} + /* * The ioctl parameter block consists of two parts, a dm_ioctl struct * followed by a data buffer. This flag is set if the second part, @@ -1691,6 +1729,7 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}, {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll}, {DM_GET_TARGET_VERSION, 0, get_target_version}, + {DM_DEV_REMAP_CMD, 0, dev_remap}, }; if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index 00774b5d7668..ffb8b5ca4d10 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -28,12 +28,13 @@ struct linear_c { */ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) { + fmode_t mode; struct linear_c *lc; unsigned long long tmp; char dummy; int ret; - if (argc != 2) { + if ((argc < 2) || (argc > 3)) { ti->error = "Invalid argument count"; return -EINVAL; } @@ -51,7 +52,19 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) } lc->start = tmp; - ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev); + ti->non_exclusive = false; + if (argc > 2) { + if (strcmp("noexcl", argv[2]) == 0) + ti->non_exclusive = true; + else if (strcmp("excl", argv[2]) == 0) + ti->non_exclusive = false; + else { + ti->error = "Invalid exclusive option"; + return -EINVAL; + } + } + + ret = dm_get_device(ti, argv[0], mode, &lc->dev); if (ret) { ti->error = "Device lookup failed"; goto bad; diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 4acf2342f7ad..f15bc2171f25 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -322,7 +322,7 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev, * device and not to touch the existing bdev field in case * it is accessed concurrently. */ -static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, +static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, bool non_exclusive, struct mapped_device *md) { int r; @@ -330,7 +330,7 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, old_dev = dd->dm_dev; - r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev, + r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev, non_exclusive, dd->dm_dev->mode | new_mode, &new_dev); if (r) return r; @@ -387,7 +387,8 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, if (!dd) return -ENOMEM; - if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) { + r = dm_get_table_device(t->md, dev, mode, ti->non_exclusive, &dd->dm_dev); + if (r) { kfree(dd); return r; } @@ -396,8 +397,9 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, list_add(&dd->list, &t->devices); goto out; - } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) { - r = upgrade_mode(dd, mode, t->md); + } else if ((dd->dm_dev->mode != (mode | dd->dm_dev->mode)) && + (dd->dm_dev->non_exclusive != ti->non_exclusive)) { + r = upgrade_mode(dd, mode, ti->non_exclusive, t->md); if (r) return r; } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 7bac564f3faa..3b871d98b7b6 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -28,6 +28,7 @@ #include #include #include +#include #define DM_MSG_PREFIX "core" @@ -56,6 +57,8 @@ static struct workqueue_struct *deferred_remove_workqueue; atomic_t dm_global_event_nr = ATOMIC_INIT(0); DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq); +static DEFINE_MUTEX(interposer_mutex); /* synchronizing access to blk_interposer */ + void dm_issue_global_event(void) { atomic_inc(&dm_global_event_nr); @@ -162,6 +165,26 @@ struct table_device { struct dm_dev dm_dev; }; +/* + * Device mapper`s interposer. + */ +struct dm_interposer { + struct blk_interposer blk_ip; + struct mapped_device *md; + + struct kref kref; + struct rw_semaphore ip_devs_lock; + struct rb_root_cached ip_devs_root; /* dm_interposed_dev tree */ +}; + +/* + * Interval tree for device mapper + */ +#define START(node) ((node)->start) +#define LAST(node) ((node)->last) +INTERVAL_TREE_DEFINE(struct dm_rb_range, node, sector_t, _subtree_last, + START, LAST,, dm_rb); + /* * Bio-based DM's mempools' reserved IOs set by the user. */ @@ -733,28 +756,340 @@ static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) rcu_read_unlock(); } +static void dm_submit_bio_interposer_fn(struct bio *bio) +{ + struct dm_interposer *ip; + unsigned int noio_flag = 0; + sector_t start; + sector_t last; + struct dm_rb_range *node; + + ip = container_of(bio->bi_disk->interposer, struct dm_interposer, blk_ip); + start = bio->bi_iter.bi_sector; + last = start + dm_sector_div_up(bio->bi_iter.bi_size, SECTOR_SIZE); + + noio_flag = memalloc_noio_save(); + down_read(&ip->ip_devs_lock); + node = dm_rb_iter_first(&ip->ip_devs_root, start, last); + while (node) { + struct dm_interposed_dev *ip_dev = + container_of(node, struct dm_interposed_dev, node); + + atomic64_inc(&ip_dev->ip_cnt); + ip_dev->dm_interpose_bio(ip_dev->context, node, bio); + + node = dm_rb_iter_next(node, start, last); + } + up_read(&ip->ip_devs_lock); + memalloc_noio_restore(noio_flag); +} + +static void free_interposer(struct kref *kref) +{ + struct dm_interposer *ip = container_of(kref, struct dm_interposer, kref); + + blk_interposer_detach(&ip->blk_ip, dm_submit_bio_interposer_fn); + + kfree(ip); +} + +static struct dm_interposer *new_interposer(struct gendisk *disk) +{ + int ret = 0; + struct dm_interposer *ip; + + ip = kzalloc(sizeof(struct dm_interposer), GFP_NOIO); + if (!ip) + return ERR_PTR(-ENOMEM); + + kref_init(&ip->kref); + init_rwsem(&ip->ip_devs_lock); + ip->ip_devs_root = RB_ROOT_CACHED; + + ret = blk_interposer_attach(disk, &ip->blk_ip, dm_submit_bio_interposer_fn); + if (ret) { + DMERR("Failed to attack blk_interposer"); + kref_put(&ip->kref, free_interposer); + return ERR_PTR(ret); + } + + return ip; +} + +static struct dm_interposer *get_interposer(struct gendisk *disk) +{ + struct dm_interposer *ip; + + if (!blk_has_interposer(disk)) + return NULL; + + if (disk->interposer->ip_submit_bio != dm_submit_bio_interposer_fn) { + DMERR("Disks interposer slot already occupied."); + return ERR_PTR(-EBUSY); + } + + ip = container_of(disk->interposer, struct dm_interposer, blk_ip); + + kref_get(&ip->kref); + return ip; +} + +struct dm_interposed_dev *dm_interposer_new_dev(struct gendisk *disk, sector_t ofs, sector_t len, + void *context, dm_interpose_bio_t dm_interpose_bio) +{ + sector_t start = ofs; + sector_t last = ofs + len - 1; + struct dm_interposed_dev *ip_dev = NULL; + + /* Allocate new ip_dev */ + ip_dev = kzalloc(sizeof(struct dm_interposed_dev), GFP_KERNEL); + if (!ip_dev) + return NULL; + + ip_dev->disk = disk; + ip_dev->node.start = start; + ip_dev->node.last = last; + + ip_dev->context = context; + ip_dev->dm_interpose_bio = dm_interpose_bio; + + atomic64_set(&ip_dev->ip_cnt, 0); + + return ip_dev; +} + +void dm_interposer_free_dev(struct dm_interposed_dev *ip_dev) +{ + kfree(ip_dev); +} + +static inline void dm_disk_freeze(struct gendisk *disk) +{ + blk_mq_freeze_queue(disk->queue); + blk_mq_quiesce_queue(disk->queue); +} + +static inline void dm_disk_unfreeze(struct gendisk *disk) +{ + blk_mq_unquiesce_queue(disk->queue); + blk_mq_unfreeze_queue(disk->queue); +} + +int dm_interposer_attach_dev(struct dm_interposed_dev *ip_dev) +{ + int ret = 0; + struct dm_interposer *ip = NULL; + unsigned int noio_flag = 0; + + if (!ip_dev) + return -EINVAL; + + dm_disk_freeze(ip_dev->disk); + mutex_lock(&interposer_mutex); + noio_flag = memalloc_noio_save(); + + ip = get_interposer(ip_dev->disk); + if (ip == NULL) + ip = new_interposer(ip_dev->disk); + if (IS_ERR(ip)) { + ret = PTR_ERR(ip); + goto out; + } + + /* Attach dm_interposed_dev to dm_interposer */ + down_write(&ip->ip_devs_lock); + do { + struct dm_rb_range *node; + + /* checking that ip_dev already exists for this region */ + node = dm_rb_iter_first(&ip->ip_devs_root, ip_dev->node.start, ip_dev->node.last); + if (node) { + DMERR("Disk part form [%llu] to [%llu] already have interposer", + node->start, node->last); + + ret = -EBUSY; + break; + } + + /* insert ip_dev to ip tree */ + dm_rb_insert(&ip_dev->node, &ip->ip_devs_root); + /* increment ip reference counter */ + kref_get(&ip->kref); + } while (false); + up_write(&ip->ip_devs_lock); + + kref_put(&ip->kref, free_interposer); + +out: + memalloc_noio_restore(noio_flag); + mutex_unlock(&interposer_mutex); + dm_disk_unfreeze(ip_dev->disk); + + return ret; +} + +int dm_interposer_detach_dev(struct dm_interposed_dev *ip_dev) +{ + int ret = 0; + struct dm_interposer *ip = NULL; + unsigned int noio_flag = 0; + + if (!ip_dev) + return -EINVAL; + + dm_disk_freeze(ip_dev->disk); + mutex_lock(&interposer_mutex); + noio_flag = memalloc_noio_save(); + + ip = get_interposer(ip_dev->disk); + if (IS_ERR(ip)) { + ret = PTR_ERR(ip); + DMERR("Interposer not found"); + goto out; + } + if (unlikely(ip == NULL)) { + ret = -ENXIO; + DMERR("Interposer not found"); + goto out; + } + + down_write(&ip->ip_devs_lock); + do { + dm_rb_remove(&ip_dev->node, &ip->ip_devs_root); + /* the reference counter here cannot be zero */ + kref_put(&ip->kref, free_interposer); + + } while (false); + up_write(&ip->ip_devs_lock); + + /* detach and free interposer if it`s not needed */ + kref_put(&ip->kref, free_interposer); +out: + memalloc_noio_restore(noio_flag); + mutex_unlock(&interposer_mutex); + dm_disk_unfreeze(ip_dev->disk); + + return ret; +} + +static void dm_remap_fn(void *context, struct dm_rb_range *node, struct bio *bio) +{ + struct mapped_device *md = context; + + /* Set acceptor device. */ + bio->bi_disk = md->disk; + + /* Remap disks offset */ + bio->bi_iter.bi_sector -= node->start; + + /* + * bio should be resubmitted. + * We can just add bio to bio_list of the current process. + * current->bio_list must be initialized when this function is called. + * If call submit_bio_noacct(), the bio will be checked twice. + */ + BUG_ON(!current->bio_list); + bio_list_add(¤t->bio_list[0], bio); +} + +int dm_remap_install(struct mapped_device *md, const char *donor_device_name) +{ + int ret = 0; + struct block_device *donor_bdev; + fmode_t mode = FMODE_READ | FMODE_WRITE; + + DMDEBUG("Dm remap install for mapped device %s and donor device %s", + md->name, donor_device_name); + + donor_bdev = blkdev_get_by_path(donor_device_name, mode, "device-mapper remap"); + if (IS_ERR(donor_bdev)) { + DMERR("Cannot open device [%s]", donor_device_name); + return PTR_ERR(donor_bdev); + } + + do { + sector_t ofs = get_start_sect(donor_bdev); + sector_t len = bdev_nr_sectors(donor_bdev); + + md->ip_dev = dm_interposer_new_dev(donor_bdev->bd_disk, ofs, len, md, dm_remap_fn); + if (!md->ip_dev) { + ret = -ENOMEM; + break; + } + + DMDEBUG("New interposed device 0x%p", md->ip_dev); + ret = dm_interposer_attach_dev(md->ip_dev); + if (ret) { + dm_interposer_free_dev(md->ip_dev); + + md->ip_dev = NULL; + DMERR("Failed to attach dm interposer"); + break; + } + + DMDEBUG("Attached successfully."); + } while (false); + + blkdev_put(donor_bdev, mode); + + return ret; +} + +int dm_remap_uninstall(struct mapped_device *md) +{ + int ret = 0; + + DMDEBUG("Dm remap uninstall for mapped device %s ip_dev=0x%p", md->name, md->ip_dev); + + if (!md->ip_dev) { + DMERR("Cannot detach dm interposer"); + return -EINVAL; + } + + ret = dm_interposer_detach_dev(md->ip_dev); + if (ret) { + DMERR("Failed to detach dm interposer"); + return ret; + } + + DMDEBUG("Detached successfully. %llu bios was interposed", + atomic64_read(&md->ip_dev->ip_cnt)); + dm_interposer_free_dev(md->ip_dev); + md->ip_dev = NULL; + + return 0; +} + static char *_dm_claim_ptr = "I belong to device-mapper"; /* * Open a table device so we can use it as a map destination. */ static int open_table_device(struct table_device *td, dev_t dev, - struct mapped_device *md) + struct mapped_device *md, bool non_exclusive) { struct block_device *bdev; - - int r; + int ret; BUG_ON(td->dm_dev.bdev); - bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr); - if (IS_ERR(bdev)) - return PTR_ERR(bdev); + if (non_exclusive) + bdev = blkdev_get_by_dev(dev, td->dm_dev.mode, NULL); + else + bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr); - r = bd_link_disk_holder(bdev, dm_disk(md)); - if (r) { - blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL); - return r; + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); + if (ret != -EBUSY) + return ret; + } + + if (!non_exclusive) { + ret = bd_link_disk_holder(bdev, dm_disk(md)); + if (ret) { + blkdev_put(bdev, td->dm_dev.mode); + return ret; + } } td->dm_dev.bdev = bdev; @@ -770,33 +1105,38 @@ static void close_table_device(struct table_device *td, struct mapped_device *md if (!td->dm_dev.bdev) return; - bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); - blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); + if (td->dm_dev.mode & FMODE_EXCL) + bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); + + blkdev_put(td->dm_dev.bdev, td->dm_dev.mode); + put_dax(td->dm_dev.dax_dev); td->dm_dev.bdev = NULL; td->dm_dev.dax_dev = NULL; } static struct table_device *find_table_device(struct list_head *l, dev_t dev, - fmode_t mode) + fmode_t mode, bool non_exclusive) { struct table_device *td; list_for_each_entry(td, l, list) - if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode) + if (td->dm_dev.bdev->bd_dev == dev && + td->dm_dev.mode == mode && + td->dm_dev.non_exclusive == non_exclusive) return td; return NULL; } -int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, +int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, bool non_exclusive, struct dm_dev **result) { int r; struct table_device *td; mutex_lock(&md->table_devices_lock); - td = find_table_device(&md->table_devices, dev, mode); + td = find_table_device(&md->table_devices, dev, mode, non_exclusive); if (!td) { td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id); if (!td) { @@ -807,7 +1147,8 @@ int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, td->dm_dev.mode = mode; td->dm_dev.bdev = NULL; - if ((r = open_table_device(td, dev, md))) { + r = open_table_device(td, dev, md, non_exclusive); + if (r) { mutex_unlock(&md->table_devices_lock); kfree(td); return r; @@ -2182,6 +2523,14 @@ static void __dm_destroy(struct mapped_device *md, bool wait) might_sleep(); + if (md->ip_dev) { + if (dm_interposer_detach_dev(md->ip_dev)) + DMERR("Failed to detach dm interposer"); + + dm_interposer_free_dev(md->ip_dev); + md->ip_dev = NULL; + } + spin_lock(&_minor_lock); idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); set_bit(DMF_FREEING, &md->flags); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index fffe1e289c53..7bf20fb2de74 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -179,7 +179,7 @@ int dm_open_count(struct mapped_device *md); int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); int dm_cancel_deferred_remove(struct mapped_device *md); int dm_request_based(struct mapped_device *md); -int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, +int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, bool non_exclusive, struct dm_dev **result); void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 61a66fb8ebb3..70002363bfc0 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -150,6 +150,7 @@ struct dm_dev { struct block_device *bdev; struct dax_device *dax_dev; fmode_t mode; + bool non_exclusive; char name[16]; }; @@ -325,6 +326,12 @@ struct dm_target { * whether or not its underlying devices have support. */ bool discards_supported:1; + + /* + * Set if this target needs to open device without FMODE_EXCL + * mode. + */ + bool non_exclusive:1; }; void *dm_per_bio_data(struct bio *bio, size_t data_size); diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index 4933b6b67b85..08d7dbff80f4 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -214,6 +214,15 @@ struct dm_target_msg { char message[0]; }; +enum { + REMAP_START_CMD = 1, + REMAP_FINISH_CMD, +}; + +struct dm_remap_param { + uint8_t cmd; + uint8_t params[0]; +}; /* * If you change this make sure you make the corresponding change * to dm-ioctl.c:lookup_ioctl() @@ -244,6 +253,7 @@ enum { DM_DEV_SET_GEOMETRY_CMD, DM_DEV_ARM_POLL_CMD, DM_GET_TARGET_VERSION_CMD, + DM_DEV_REMAP_CMD }; #define DM_IOCTL 0xfd @@ -259,6 +269,7 @@ enum { #define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl) #define DM_DEV_WAIT _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl) #define DM_DEV_ARM_POLL _IOWR(DM_IOCTL, DM_DEV_ARM_POLL_CMD, struct dm_ioctl) +#define DM_DEV_REMAP _IOWR(DM_IOCTL, DM_DEV_REMAP_CMD, struct dm_ioctl) #define DM_TABLE_LOAD _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl) #define DM_TABLE_CLEAR _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl) @@ -272,9 +283,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 43 +#define DM_VERSION_MINOR 44 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2020-10-01)" +#define DM_VERSION_EXTRA "-ioctl (2020-12-25)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */