From e046114af5fcafe8d6d3f0b6ccb99804bad34bfb Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Fri, 30 Sep 2016 17:19:31 -0600 Subject: libnvdimm: clear the internal poison_list when clearing badblocks nvdimm_clear_poison cleared the user-visible badblocks, and sent commands to the NVDIMM to clear the areas marked as 'poison', but it neglected to clear the same areas from the internal poison_list which is used to marshal ARS results before sorting them by namespace. As a result, once on-demand ARS functionality was added: 37b137f nfit, libnvdimm: allow an ARS scrub to be triggered on demand A scrub triggered from either sysfs or an MCE was found to be adding stale entries that had been cleared from gendisk->badblocks, but were still present in nvdimm_bus->poison_list. Additionally, the stale entries could be triggered into producing stale disk->badblocks by simply disabling and re-enabling the namespace or region. This adds the missing step of clearing poison_list entries when clearing poison, so that it is always in sync with badblocks. Fixes: 37b137f ("nfit, libnvdimm: allow an ARS scrub to be triggered on demand") Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/nvdimm/bus.c | 2 ++ drivers/nvdimm/core.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 71 insertions(+), 4 deletions(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 458daf927336..8493a2559daa 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -213,6 +213,8 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys, return rc; if (cmd_rc < 0) return cmd_rc; + + nvdimm_clear_from_poison_list(nvdimm_bus, phys, len); return clear_err.cleared; } EXPORT_SYMBOL_GPL(nvdimm_clear_poison); diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c index 715583f69d28..42e40db4651b 100644 --- a/drivers/nvdimm/core.c +++ b/drivers/nvdimm/core.c @@ -541,11 +541,12 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region, } EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate); -static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) +static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length, + gfp_t flags) { struct nd_poison *pl; - pl = kzalloc(sizeof(*pl), GFP_KERNEL); + pl = kzalloc(sizeof(*pl), flags); if (!pl) return -ENOMEM; @@ -561,7 +562,7 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) struct nd_poison *pl; if (list_empty(&nvdimm_bus->poison_list)) - return add_poison(nvdimm_bus, addr, length); + return add_poison(nvdimm_bus, addr, length, GFP_KERNEL); /* * There is a chance this is a duplicate, check for those first. @@ -581,7 +582,7 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) * as any overlapping ranges will get resolved when the list is consumed * and converted to badblocks */ - return add_poison(nvdimm_bus, addr, length); + return add_poison(nvdimm_bus, addr, length, GFP_KERNEL); } int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) @@ -596,6 +597,70 @@ int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) } EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison); +void nvdimm_clear_from_poison_list(struct nvdimm_bus *nvdimm_bus, + phys_addr_t start, unsigned int len) +{ + struct list_head *poison_list = &nvdimm_bus->poison_list; + u64 clr_end = start + len - 1; + struct nd_poison *pl, *next; + + nvdimm_bus_lock(&nvdimm_bus->dev); + WARN_ON_ONCE(list_empty(poison_list)); + + /* + * [start, clr_end] is the poison interval being cleared. + * [pl->start, pl_end] is the poison_list entry we're comparing + * the above interval against. The poison list entry may need + * to be modified (update either start or length), deleted, or + * split into two based on the overlap characteristics + */ + + list_for_each_entry_safe(pl, next, poison_list, list) { + u64 pl_end = pl->start + pl->length - 1; + + /* Skip intervals with no intersection */ + if (pl_end < start) + continue; + if (pl->start > clr_end) + continue; + /* Delete completely overlapped poison entries */ + if ((pl->start >= start) && (pl_end <= clr_end)) { + list_del(&pl->list); + kfree(pl); + continue; + } + /* Adjust start point of partially cleared entries */ + if ((start <= pl->start) && (clr_end > pl->start)) { + pl->length -= clr_end - pl->start + 1; + pl->start = clr_end + 1; + continue; + } + /* Adjust pl->length for partial clearing at the tail end */ + if ((pl->start < start) && (pl_end <= clr_end)) { + /* pl->start remains the same */ + pl->length = start - pl->start; + continue; + } + /* + * If clearing in the middle of an entry, we split it into + * two by modifying the current entry to represent one half of + * the split, and adding a new entry for the second half. + */ + if ((pl->start < start) && (pl_end > clr_end)) { + u64 new_start = clr_end + 1; + u64 new_len = pl_end - new_start + 1; + + /* Add new entry covering the right half */ + add_poison(nvdimm_bus, new_start, new_len, GFP_NOIO); + /* Adjust this entry to cover the left half */ + pl->length = start - pl->start; + continue; + } + } + nvdimm_bus_unlock(&nvdimm_bus->dev); +} +EXPORT_SYMBOL_GPL(nvdimm_clear_from_poison_list); + #ifdef CONFIG_BLK_DEV_INTEGRITY int nd_integrity_init(struct gendisk *disk, unsigned long meta_size) { -- cgit