Use the guard(device) macro to lock a 'struct device', and unlock it automatically when going out of scope using Scope Based Resource Management semantics. A lot of the sysfs attribute writes in drivers/dax/bus.c benefit from a cleanup using these, so change these where applicable. Cc: Joao Martins <joao.m.martins@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx> --- drivers/dax/bus.c | 143 ++++++++++++++++++++++-------------------------------- 1 file changed, 59 insertions(+), 84 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 1ff1ab5fa105..6226de131d17 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -294,13 +294,10 @@ static ssize_t available_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct dax_region *dax_region = dev_get_drvdata(dev); - unsigned long long size; - device_lock(dev); - size = dax_region_avail_size(dax_region); - device_unlock(dev); + guard(device)(dev); - return sprintf(buf, "%llu\n", size); + return sprintf(buf, "%llu\n", dax_region_avail_size(dax_region)); } static DEVICE_ATTR_RO(available_size); @@ -309,17 +306,14 @@ static ssize_t seed_show(struct device *dev, { struct dax_region *dax_region = dev_get_drvdata(dev); struct device *seed; - ssize_t rc; if (is_static(dax_region)) return -EINVAL; - device_lock(dev); + guard(device)(dev); seed = dax_region->seed; - rc = sprintf(buf, "%s\n", seed ? dev_name(seed) : ""); - device_unlock(dev); - return rc; + return sprintf(buf, "%s\n", seed ? dev_name(seed) : ""); } static DEVICE_ATTR_RO(seed); @@ -328,24 +322,28 @@ static ssize_t create_show(struct device *dev, { struct dax_region *dax_region = dev_get_drvdata(dev); struct device *youngest; - ssize_t rc; if (is_static(dax_region)) return -EINVAL; - device_lock(dev); + guard(device)(dev); youngest = dax_region->youngest; - rc = sprintf(buf, "%s\n", youngest ? dev_name(youngest) : ""); - device_unlock(dev); - return rc; + return sprintf(buf, "%s\n", youngest ? dev_name(youngest) : ""); } static ssize_t create_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct dax_region *dax_region = dev_get_drvdata(dev); + struct dev_dax_data data = { + .dax_region = dax_region, + .size = 0, + .id = -1, + .memmap_on_memory = false, + }; unsigned long long avail; + struct dev_dax *dev_dax; ssize_t rc; int val; @@ -358,38 +356,25 @@ static ssize_t create_store(struct device *dev, struct device_attribute *attr, if (val != 1) return -EINVAL; - device_lock(dev); + guard(device)(dev); avail = dax_region_avail_size(dax_region); if (avail == 0) - rc = -ENOSPC; - else { - struct dev_dax_data data = { - .dax_region = dax_region, - .size = 0, - .id = -1, - .memmap_on_memory = false, - }; - struct dev_dax *dev_dax = devm_create_dev_dax(&data); + return -ENOSPC; - if (IS_ERR(dev_dax)) - rc = PTR_ERR(dev_dax); - else { - /* - * In support of crafting multiple new devices - * simultaneously multiple seeds can be created, - * but only the first one that has not been - * successfully bound is tracked as the region - * seed. - */ - if (!dax_region->seed) - dax_region->seed = &dev_dax->dev; - dax_region->youngest = &dev_dax->dev; - rc = len; - } - } - device_unlock(dev); + dev_dax = devm_create_dev_dax(&data); + if (IS_ERR(dev_dax)) + return PTR_ERR(dev_dax); - return rc; + /* + * In support of crafting multiple new devices simultaneously multiple + * seeds can be created, but only the first one that has not been + * successfully bound is tracked as the region seed. + */ + if (!dax_region->seed) + dax_region->seed = &dev_dax->dev; + dax_region->youngest = &dev_dax->dev; + + return len; } static DEVICE_ATTR_RW(create); @@ -481,12 +466,9 @@ static int __free_dev_dax_id(struct dev_dax *dev_dax) static int free_dev_dax_id(struct dev_dax *dev_dax) { struct device *dev = &dev_dax->dev; - int rc; - device_lock(dev); - rc = __free_dev_dax_id(dev_dax); - device_unlock(dev); - return rc; + guard(device)(dev); + return __free_dev_dax_id(dev_dax); } static int alloc_dev_dax_id(struct dev_dax *dev_dax) @@ -908,9 +890,8 @@ static ssize_t size_show(struct device *dev, struct dev_dax *dev_dax = to_dev_dax(dev); unsigned long long size; - device_lock(dev); + guard(device)(dev); size = dev_dax_size(dev_dax); - device_unlock(dev); return sprintf(buf, "%llu\n", size); } @@ -1080,17 +1061,16 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr, return -EINVAL; } - device_lock(dax_region->dev); - if (!dax_region->dev->driver) { - device_unlock(dax_region->dev); + guard(device)(dax_region->dev); + if (!dax_region->dev->driver) return -ENXIO; - } - device_lock(dev); + + guard(device)(dev); rc = dev_dax_resize(dax_region, dev_dax, val); - device_unlock(dev); - device_unlock(dax_region->dev); + if (rc) + return rc; - return rc == 0 ? len : rc; + return len; } static DEVICE_ATTR_RW(size); @@ -1137,21 +1117,20 @@ static ssize_t mapping_store(struct device *dev, struct device_attribute *attr, if (rc) return rc; - rc = -ENXIO; - device_lock(dax_region->dev); - if (!dax_region->dev->driver) { - device_unlock(dax_region->dev); - return rc; - } - device_lock(dev); + guard(device)(dax_region->dev); + if (!dax_region->dev->driver) + return -ENXIO; + guard(device)(dev); to_alloc = range_len(&r); - if (alloc_is_aligned(dev_dax, to_alloc)) - rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); - device_unlock(dev); - device_unlock(dax_region->dev); + if (!alloc_is_aligned(dev_dax, to_alloc)) + return -ENXIO; - return rc == 0 ? len : rc; + rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); + if (rc) + return rc; + + return len; } static DEVICE_ATTR_WO(mapping); @@ -1196,27 +1175,23 @@ static ssize_t align_store(struct device *dev, struct device_attribute *attr, if (!dax_align_valid(val)) return -EINVAL; - device_lock(dax_region->dev); - if (!dax_region->dev->driver) { - device_unlock(dax_region->dev); + guard(device)(dax_region->dev); + if (!dax_region->dev->driver) return -ENXIO; - } - device_lock(dev); - if (dev->driver) { - rc = -EBUSY; - goto out_unlock; - } + guard(device)(dev); + if (dev->driver) + return -EBUSY; align_save = dev_dax->align; dev_dax->align = val; rc = dev_dax_validate_align(dev_dax); - if (rc) + if (rc) { dev_dax->align = align_save; -out_unlock: - device_unlock(dev); - device_unlock(dax_region->dev); - return rc == 0 ? len : rc; + return rc; + } + + return len; } static DEVICE_ATTR_RW(align); -- 2.41.0