From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- drivers/nvdimm/btt_devs.c | 219 +++++++++++----------------------------------- 1 file changed, 50 insertions(+), 169 deletions(-) (limited to 'drivers/nvdimm/btt_devs.c') diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c index 6ac8c0fea..cb477518d 100644 --- a/drivers/nvdimm/btt_devs.c +++ b/drivers/nvdimm/btt_devs.c @@ -21,63 +21,13 @@ #include "btt.h" #include "nd.h" -static void __nd_btt_detach_ndns(struct nd_btt *nd_btt) -{ - struct nd_namespace_common *ndns = nd_btt->ndns; - - dev_WARN_ONCE(&nd_btt->dev, !mutex_is_locked(&ndns->dev.mutex) - || ndns->claim != &nd_btt->dev, - "%s: invalid claim\n", __func__); - ndns->claim = NULL; - nd_btt->ndns = NULL; - put_device(&ndns->dev); -} - -static void nd_btt_detach_ndns(struct nd_btt *nd_btt) -{ - struct nd_namespace_common *ndns = nd_btt->ndns; - - if (!ndns) - return; - get_device(&ndns->dev); - device_lock(&ndns->dev); - __nd_btt_detach_ndns(nd_btt); - device_unlock(&ndns->dev); - put_device(&ndns->dev); -} - -static bool __nd_btt_attach_ndns(struct nd_btt *nd_btt, - struct nd_namespace_common *ndns) -{ - if (ndns->claim) - return false; - dev_WARN_ONCE(&nd_btt->dev, !mutex_is_locked(&ndns->dev.mutex) - || nd_btt->ndns, - "%s: invalid claim\n", __func__); - ndns->claim = &nd_btt->dev; - nd_btt->ndns = ndns; - get_device(&ndns->dev); - return true; -} - -static bool nd_btt_attach_ndns(struct nd_btt *nd_btt, - struct nd_namespace_common *ndns) -{ - bool claimed; - - device_lock(&ndns->dev); - claimed = __nd_btt_attach_ndns(nd_btt, ndns); - device_unlock(&ndns->dev); - return claimed; -} - static void nd_btt_release(struct device *dev) { struct nd_region *nd_region = to_nd_region(dev->parent); struct nd_btt *nd_btt = to_nd_btt(dev); dev_dbg(dev, "%s\n", __func__); - nd_btt_detach_ndns(nd_btt); + nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns); ida_simple_remove(&nd_region->btt_ida, nd_btt->id); kfree(nd_btt->uuid); kfree(nd_btt); @@ -172,108 +122,19 @@ static ssize_t namespace_show(struct device *dev, return rc; } -static int namespace_match(struct device *dev, void *data) -{ - char *name = data; - - return strcmp(name, dev_name(dev)) == 0; -} - -static bool is_nd_btt_idle(struct device *dev) -{ - struct nd_region *nd_region = to_nd_region(dev->parent); - struct nd_btt *nd_btt = to_nd_btt(dev); - - if (nd_region->btt_seed == dev || nd_btt->ndns || dev->driver) - return false; - return true; -} - -static ssize_t __namespace_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - struct nd_btt *nd_btt = to_nd_btt(dev); - struct nd_namespace_common *ndns; - struct device *found; - char *name; - - if (dev->driver) { - dev_dbg(dev, "%s: -EBUSY\n", __func__); - return -EBUSY; - } - - name = kstrndup(buf, len, GFP_KERNEL); - if (!name) - return -ENOMEM; - strim(name); - - if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0) - /* pass */; - else { - len = -EINVAL; - goto out; - } - - ndns = nd_btt->ndns; - if (strcmp(name, "") == 0) { - /* detach the namespace and destroy / reset the btt device */ - nd_btt_detach_ndns(nd_btt); - if (is_nd_btt_idle(dev)) - nd_device_unregister(dev, ND_ASYNC); - else { - nd_btt->lbasize = 0; - kfree(nd_btt->uuid); - nd_btt->uuid = NULL; - } - goto out; - } else if (ndns) { - dev_dbg(dev, "namespace already set to: %s\n", - dev_name(&ndns->dev)); - len = -EBUSY; - goto out; - } - - found = device_find_child(dev->parent, name, namespace_match); - if (!found) { - dev_dbg(dev, "'%s' not found under %s\n", name, - dev_name(dev->parent)); - len = -ENODEV; - goto out; - } - - ndns = to_ndns(found); - if (__nvdimm_namespace_capacity(ndns) < SZ_16M) { - dev_dbg(dev, "%s too small to host btt\n", name); - len = -ENXIO; - goto out_attach; - } - - WARN_ON_ONCE(!is_nvdimm_bus_locked(&nd_btt->dev)); - if (!nd_btt_attach_ndns(nd_btt, ndns)) { - dev_dbg(dev, "%s already claimed\n", - dev_name(&ndns->dev)); - len = -EBUSY; - } - - out_attach: - put_device(&ndns->dev); /* from device_find_child */ - out: - kfree(name); - return len; -} - static ssize_t namespace_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { + struct nd_btt *nd_btt = to_nd_btt(dev); ssize_t rc; - nvdimm_bus_lock(dev); device_lock(dev); - rc = __namespace_store(dev, attr, buf, len); + nvdimm_bus_lock(dev); + rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len); dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__, rc, buf, buf[len - 1] == '\n' ? "" : "\n"); - device_unlock(dev); nvdimm_bus_unlock(dev); + device_unlock(dev); return rc; } @@ -324,7 +185,7 @@ static struct device *__nd_btt_create(struct nd_region *nd_region, dev->type = &nd_btt_device_type; dev->groups = nd_btt_attribute_groups; device_initialize(&nd_btt->dev); - if (ndns && !__nd_btt_attach_ndns(nd_btt, ndns)) { + if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) { dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n", __func__, dev_name(ndns->claim)); put_device(dev); @@ -342,30 +203,54 @@ struct device *nd_btt_create(struct nd_region *nd_region) return dev; } -/* - * nd_btt_sb_checksum: compute checksum for btt info block +static bool uuid_is_null(u8 *uuid) +{ + static const u8 null_uuid[16]; + + return (memcmp(uuid, null_uuid, 16) == 0); +} + +/** + * nd_btt_arena_is_valid - check if the metadata layout is valid + * @nd_btt: device with BTT geometry and backing device info + * @super: pointer to the arena's info block being tested * - * Returns a fletcher64 checksum of everything in the given info block - * except the last field (since that's where the checksum lives). + * Check consistency of the btt info block with itself by validating + * the checksum, and with the parent namespace by verifying the + * parent_uuid contained in the info block with the one supplied in. + * + * Returns: + * false for an invalid info block, true for a valid one */ -u64 nd_btt_sb_checksum(struct btt_sb *btt_sb) +bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super) { - u64 sum; - __le64 sum_save; - - sum_save = btt_sb->checksum; - btt_sb->checksum = 0; - sum = nd_fletcher64(btt_sb, sizeof(*btt_sb), 1); - btt_sb->checksum = sum_save; - return sum; + const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev); + u64 checksum; + + if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0) + return false; + + if (!uuid_is_null(super->parent_uuid)) + if (memcmp(super->parent_uuid, parent_uuid, 16) != 0) + return false; + + checksum = le64_to_cpu(super->checksum); + super->checksum = 0; + if (checksum != nd_sb_checksum((struct nd_gen_sb *) super)) + return false; + super->checksum = cpu_to_le64(checksum); + + /* TODO: figure out action for this */ + if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0) + dev_info(&nd_btt->dev, "Found arena with an error flag\n"); + + return true; } -EXPORT_SYMBOL(nd_btt_sb_checksum); +EXPORT_SYMBOL(nd_btt_arena_is_valid); static int __nd_btt_probe(struct nd_btt *nd_btt, struct nd_namespace_common *ndns, struct btt_sb *btt_sb) { - u64 checksum; - if (!btt_sb || !ndns || !nd_btt) return -ENODEV; @@ -375,14 +260,8 @@ static int __nd_btt_probe(struct nd_btt *nd_btt, if (nvdimm_namespace_capacity(ndns) < SZ_16M) return -ENXIO; - if (memcmp(btt_sb->signature, BTT_SIG, BTT_SIG_LEN) != 0) - return -ENODEV; - - checksum = le64_to_cpu(btt_sb->checksum); - btt_sb->checksum = 0; - if (checksum != nd_btt_sb_checksum(btt_sb)) + if (!nd_btt_arena_is_valid(nd_btt, btt_sb)) return -ENODEV; - btt_sb->checksum = cpu_to_le64(checksum); nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize); nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL); @@ -416,7 +295,9 @@ int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata) dev_dbg(&ndns->dev, "%s: btt: %s\n", __func__, rc == 0 ? dev_name(dev) : ""); if (rc < 0) { - __nd_btt_detach_ndns(to_nd_btt(dev)); + struct nd_btt *nd_btt = to_nd_btt(dev); + + __nd_detach_ndns(dev, &nd_btt->ndns); put_device(dev); } -- cgit v1.2.3-54-g00ecf