Upon detection of a read-only backing device arrange for the btt to device to be read only. Implement a catch for the BLKROSET ioctl and only allow a btt-instance to become read-write when the backing-device becomes read-write. Conversely, if a backing-device becomes read-only arrange for its parent btt to be marked read-only. Synchronize these changes under the bus lock.
Signed-off-by: Dan Williams <[email protected]> --- drivers/nvdimm/blk.c | 4 +++ drivers/nvdimm/btt.c | 34 ++++++++++++++++++++++++++-- drivers/nvdimm/btt_devs.c | 42 ++++++++++++++++++++++++++++++++++ drivers/nvdimm/bus.c | 55 +++++++++++++++++++++++++++++++++++++++++++++ drivers/nvdimm/nd-core.h | 14 +++++++++++ drivers/nvdimm/nd.h | 4 +++ drivers/nvdimm/pmem.c | 4 +++ 7 files changed, 154 insertions(+), 3 deletions(-) diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c index 8a65e5a500d8..adacc27f04f1 100644 --- a/drivers/nvdimm/blk.c +++ b/drivers/nvdimm/blk.c @@ -239,6 +239,10 @@ static int nd_blk_rw_bytes(struct gendisk *disk, resource_size_t offset, static const struct block_device_operations nd_blk_fops = { .owner = THIS_MODULE, .rw_bytes = nd_blk_rw_bytes, + .ioctl = nvdimm_bdev_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = nvdimm_bdev_compat_ioctl, +#endif }; static int nd_blk_probe(struct device *dev) diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 67484633c322..57d3b271e451 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1248,10 +1248,29 @@ static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo) return 0; } +static int btt_revalidate_disk(struct gendisk *disk) +{ + struct btt *btt = disk->private_data; + struct nd_btt *nd_btt = btt->nd_btt; + struct block_device *bdev = nd_btt->backing_dev; + char name[BDEVNAME_SIZE]; + + dev_dbg(&nd_btt->dev, "backing dev: %s read-%s", bdevname(bdev, name), + bdev_read_only(bdev) ? "only" : "write"); + if (bdev_read_only(bdev)) + set_disk_ro(disk, 1); + return 0; +} + static const struct block_device_operations btt_fops = { .owner = THIS_MODULE, .rw_page = btt_rw_page, .getgeo = btt_getgeo, + .ioctl = nvdimm_bdev_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = nvdimm_bdev_compat_ioctl, +#endif + .revalidate_disk = btt_revalidate_disk, }; static int btt_blk_init(struct btt *btt) @@ -1296,6 +1315,7 @@ static int btt_blk_init(struct btt *btt) } set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9); + revalidate_disk(btt->btt_disk); return 0; @@ -1335,6 +1355,7 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize, int ret; struct btt *btt; struct device *dev = &nd_btt->dev; + struct block_device *bdev = nd_btt->backing_dev; btt = kzalloc(sizeof(struct btt), GFP_KERNEL); if (!btt) @@ -1354,7 +1375,13 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize, goto out_free; } - if (btt->init_state != INIT_READY) { + if (btt->init_state != INIT_READY && bdev_read_only(bdev)) { + char name[BDEVNAME_SIZE]; + + dev_info(dev, "%s is read-only, unable to init btt metadata\n", + bdevname(bdev, name)); + goto out_free; + } else if (btt->init_state != INIT_READY) { btt->num_arenas = (rawsize / ARENA_MAX_SIZE) + ((rawsize % ARENA_MAX_SIZE) ? 1 : 0); dev_dbg(dev, "init: %d arenas for %llu rawsize\n", @@ -1369,7 +1396,7 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize, ret = btt_meta_init(btt); if (ret) { dev_err(dev, "init: error in meta_init: %d\n", ret); - return NULL; + goto out_free; } } @@ -1481,7 +1508,10 @@ static int nd_btt_remove(struct device *dev) struct nd_btt *nd_btt = to_nd_btt(dev); struct btt *btt = dev_get_drvdata(dev); + nvdimm_bus_lock(dev); btt_fini(btt); + nvdimm_bus_unlock(dev); + unlink_btt(nd_btt); return 0; diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c index 02e125b91e77..bcf77dca1532 100644 --- a/drivers/nvdimm/btt_devs.c +++ b/drivers/nvdimm/btt_devs.c @@ -122,7 +122,7 @@ static ssize_t backing_dev_show(struct device *dev, return sprintf(buf, "\n"); } -static const fmode_t nd_btt_devs_mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL; +static const fmode_t nd_btt_devs_mode = FMODE_READ | FMODE_EXCL; static void nd_btt_remove_bdev(struct nd_btt *nd_btt, const char *caller) { @@ -363,6 +363,46 @@ u64 nd_btt_sb_checksum(struct btt_sb *btt_sb) } EXPORT_SYMBOL(nd_btt_sb_checksum); +int set_btt_ro(struct block_device *bdev, struct device *dev, int ro) +{ + struct nd_btt *nd_btt = to_nd_btt(dev); + + if (!dev->driver) + return 0; + + /* we can only mark a btt device rw if its backing device is rw */ + if (bdev_read_only(nd_btt->backing_dev) && !ro) + return -EBUSY; + + set_device_ro(bdev, ro); + return 0; +} + +int set_btt_disk_ro(struct device *dev, void *data) +{ + struct block_device *bdev = data; + struct nd_btt *nd_btt; + struct btt *btt; + + if (!is_nd_btt(dev)) + return 0; + + nd_btt = to_nd_btt(dev); + if (nd_btt->backing_dev != bdev) + return 0; + + /* + * We have the lock at this point and have flushed probing. We + * are guaranteed that the btt driver is unbound, or has + * completed setup operations and is blocked from initiating + * disk teardown until we are done walking these pointers. + */ + btt = dev_get_drvdata(dev); + if (btt && btt->btt_disk) + set_disk_ro(btt->btt_disk, 1); + return 0; +} + static struct nd_btt *__nd_btt_autodetect(struct nvdimm_bus *nvdimm_bus, struct block_device *bdev, struct btt_sb *btt_sb) { diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index d4fbc48f5643..47260ca573e0 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -309,6 +309,61 @@ void nvdimm_bus_remove_disk(struct gendisk *disk) } EXPORT_SYMBOL(nvdimm_bus_remove_disk); +static int set_namespace_ro(struct block_device *bdev, + struct nvdimm_bus *nvdimm_bus, int ro) +{ + set_device_ro(bdev, ro); + + /* + * It's possible to mark the backing device rw while leaving the + * btt device read-only. However, marking a backing device + * read-only always marks the parent btt read-only. + */ + if (!ro) + return 0; + return device_for_each_child(&nvdimm_bus->dev, bdev, set_btt_disk_ro); +} + +int nvdimm_bdev_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + int rc, ro; + struct gendisk *disk = bdev->bd_disk; + struct device *dev = disk->driverfs_dev; + struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev); + + if (cmd != BLKROSET) + return -ENOTTY; + + if (get_user(ro, (int __user *)(arg))) + return -EFAULT; + + if (ro == 0 || ro == 1) + /* pass */; + else + return -EINVAL; + + nvdimm_bus_lock(&nvdimm_bus->dev); + wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev); + if (bdev_read_only(bdev) == ro) + rc = 0; + else if (is_nd_btt(dev)) + rc = set_btt_ro(bdev, dev, ro); + else + rc = set_namespace_ro(bdev, nvdimm_bus, ro); + nvdimm_bus_unlock(&nvdimm_bus->dev); + + return rc; +} +EXPORT_SYMBOL(nvdimm_bdev_ioctl); + +int nvdimm_bdev_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + return nvdimm_bdev_ioctl(bdev, mode, cmd, arg); +} +EXPORT_SYMBOL(nvdimm_bdev_compat_ioctl); + static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h index 9a90915e6fd2..ba548d248b4e 100644 --- a/drivers/nvdimm/nd-core.h +++ b/drivers/nvdimm/nd-core.h @@ -49,11 +49,14 @@ bool is_nvdimm(struct device *dev); bool is_nd_pmem(struct device *dev); bool is_nd_blk(struct device *dev); struct gendisk; +struct block_device; #if IS_ENABLED(CONFIG_ND_BTT_DEVS) bool is_nd_btt(struct device *dev); struct nd_btt *nd_btt_create(struct nvdimm_bus *nvdimm_bus); void nd_btt_add_disk(struct nvdimm_bus *nvdimm_bus, struct gendisk *disk); void nd_btt_remove_disk(struct nvdimm_bus *nvdimm_bus, struct gendisk *disk); +int set_btt_ro(struct block_device *bdev, struct device *dev, int ro); +int set_btt_disk_ro(struct device *dev, void *data); #else static inline bool is_nd_btt(struct device *dev) { @@ -74,6 +77,17 @@ static inline void nd_btt_remove_disk(struct nvdimm_bus *nvdimm_bus, struct gendisk *disk) { } + +static inline int set_btt_ro(struct block_device *bdev, struct device *dev, + int ro) +{ + return 0; +} + +static inline int set_btt_disk_ro(struct device *dev, void *data) +{ + return 0; +} #endif struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev); int __init nvdimm_bus_init(void); diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index 3c4c8b6c64ec..2786eb8456ec 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -164,6 +164,10 @@ int nvdimm_bus_add_disk(struct gendisk *disk); int nvdimm_bus_add_integrity_disk(struct gendisk *disk, u32 lbasize, sector_t size); void nvdimm_bus_remove_disk(struct gendisk *disk); +int nvdimm_bdev_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg); +int nvdimm_bdev_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg); void nvdimm_drvdata_release(struct kref *kref); void put_ndd(struct nvdimm_drvdata *ndd); int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 3fd854a78f09..96964419b72d 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -131,6 +131,10 @@ static const struct block_device_operations pmem_fops = { .rw_page = pmem_rw_page, .rw_bytes = pmem_rw_bytes, .direct_access = pmem_direct_access, + .ioctl = nvdimm_bdev_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = nvdimm_bdev_ioctl, +#endif }; static struct pmem_device *pmem_alloc(struct device *dev, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
