From 4e4ced93794acb42adb19484132966defba8f3a6 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 1 Apr 2020 12:11:25 -0400 Subject: [PATCH] dax: Move mandatory ->zero_page_range() check in alloc_dax() zero_page_range() dax operation is mandatory for dax devices. Right now that check happens in dax_zero_page_range() function. Dan thinks that's too late and its better to do the check earlier in alloc_dax(). I also modified alloc_dax() to return pointer with error code in it in case of failure. Right now it returns NULL and caller assumes failure happened due to -ENOMEM. But with this ->zero_page_range() check, I need to return -EINVAL instead. Signed-off-by: Vivek Goyal Link: https://lore.kernel.org/r/20200401161125.GB9398@redhat.com Signed-off-by: Dan Williams --- drivers/dax/bus.c | 4 +++- drivers/dax/super.c | 14 +++++++++----- drivers/md/dm.c | 2 +- drivers/nvdimm/pmem.c | 4 ++-- drivers/s390/block/dcssblk.c | 5 +++-- 5 files changed, 18 insertions(+), 11 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 46e46047a1f7..df238c8b6ef2 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -421,8 +421,10 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id, * device outside of mmap of the resulting character device. */ dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC); - if (!dax_dev) + if (IS_ERR(dax_dev)) { + rc = PTR_ERR(dax_dev); goto err; + } /* a device_dax instance is dead while the driver is not attached */ kill_dax(dax_dev); diff --git a/drivers/dax/super.c b/drivers/dax/super.c index e498daf3c0d7..8e32345be0f7 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -349,9 +349,6 @@ int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, { if (!dax_alive(dax_dev)) return -ENXIO; - - if (!dax_dev->ops->zero_page_range) - return -EOPNOTSUPP; /* * There are no callers that want to zero more than one page as of now. * Once users are there, this check can be removed after the @@ -571,9 +568,16 @@ struct dax_device *alloc_dax(void *private, const char *__host, dev_t devt; int minor; + if (ops && !ops->zero_page_range) { + pr_debug("%s: error: device does not provide dax" + " operation zero_page_range()\n", + __host ? __host : "Unknown"); + return ERR_PTR(-EINVAL); + } + host = kstrdup(__host, GFP_KERNEL); if (__host && !host) - return NULL; + return ERR_PTR(-ENOMEM); minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL); if (minor < 0) @@ -596,7 +600,7 @@ struct dax_device *alloc_dax(void *private, const char *__host, ida_simple_remove(&dax_minor_ida, minor); err_minor: kfree(host); - return NULL; + return ERR_PTR(-ENOMEM); } EXPORT_SYMBOL_GPL(alloc_dax); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index aa72d9e757c1..6504f0a358e5 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2005,7 +2005,7 @@ static struct mapped_device *alloc_dev(int minor) if (IS_ENABLED(CONFIG_DAX_DRIVER)) { md->dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops, 0); - if (!md->dax_dev) + if (IS_ERR(md->dax_dev)) goto bad; } diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 5b774ddd0efb..715cb0696525 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -487,9 +487,9 @@ static int pmem_attach_disk(struct device *dev, if (is_nvdimm_sync(nd_region)) flags = DAXDEV_F_SYNC; dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags); - if (!dax_dev) { + if (IS_ERR(dax_dev)) { put_disk(disk); - return -ENOMEM; + return PTR_ERR(dax_dev); } dax_write_cache(dax_dev, nvdimm_has_cache(nd_region)); pmem->dax_dev = dax_dev; diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index ab3e2898816c..9b05cf1a25c4 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -695,8 +695,9 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char dev_info->dax_dev = alloc_dax(dev_info, dev_info->gd->disk_name, &dcssblk_dax_ops, DAXDEV_F_SYNC); - if (!dev_info->dax_dev) { - rc = -ENOMEM; + if (IS_ERR(dev_info->dax_dev)) { + rc = PTR_ERR(dev_info->dax_dev); + dev_info->dax_dev = NULL; goto put_dev; } -- 2.39.5