This is a note to let you know that I've just added the patch titled libnvdimm: clear the internal poison_list when clearing badblocks to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: libnvdimm-clear-the-internal-poison_list-when-clearing-badblocks.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e046114af5fcafe8d6d3f0b6ccb99804bad34bfb Mon Sep 17 00:00:00 2001 From: Vishal Verma <vishal.l.verma@xxxxxxxxx> Date: Fri, 30 Sep 2016 17:19:31 -0600 Subject: libnvdimm: clear the internal poison_list when clearing badblocks From: Vishal Verma <vishal.l.verma@xxxxxxxxx> commit e046114af5fcafe8d6d3f0b6ccb99804bad34bfb upstream. 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 <vishal.l.verma@xxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/nvdimm/bus.c | 2 + drivers/nvdimm/core.c | 73 +++++++++++++++++++++++++++++++++++++++++++--- include/linux/libnvdimm.h | 2 + 3 files changed, 73 insertions(+), 4 deletions(-) --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -217,6 +217,8 @@ long nvdimm_clear_poison(struct device * 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); --- a/drivers/nvdimm/core.c +++ b/drivers/nvdimm/core.c @@ -547,11 +547,12 @@ void nvdimm_badblocks_populate(struct nd } 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; @@ -567,7 +568,7 @@ static int bus_add_poison(struct nvdimm_ 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. @@ -587,7 +588,7 @@ static int bus_add_poison(struct nvdimm_ * 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) @@ -602,6 +603,70 @@ int nvdimm_bus_add_poison(struct nvdimm_ } 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) { --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -129,6 +129,8 @@ static inline struct nd_blk_region_desc } int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length); +void nvdimm_clear_from_poison_list(struct nvdimm_bus *nvdimm_bus, + phys_addr_t start, unsigned int len); struct nvdimm_bus *nvdimm_bus_register(struct device *parent, struct nvdimm_bus_descriptor *nfit_desc); void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus); Patches currently in stable-queue which might be from vishal.l.verma@xxxxxxxxx are queue-4.8/libnvdimm-clear-the-internal-poison_list-when-clearing-badblocks.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html