From ab45e7632717b811e0786e46ca5ad279cb731b66 Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Wed, 29 Jul 2015 14:58:08 -0600 Subject: [PATCH] libnvdimm, btt: consolidate arena validation Use arena_is_valid as a common routine for checking the validity of an info block from both discover_arenas, and nd_btt_probe. As a result, don't check for validity of the BTT's UUID, and lbasize. The checksum in the BTT info block guarantees self-consistency, and when we're called from nd_btt_probe, we don't have a valid uuid or lbasize available to check against. Also cleanup to return a bool instead of an int. Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/nvdimm/btt.c | 28 +------------------------- drivers/nvdimm/btt.h | 3 +++ drivers/nvdimm/btt_devs.c | 42 ++++++++++++++++++++++++++++++--------- 3 files changed, 37 insertions(+), 36 deletions(-) diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 87e6a96a6c19..6567746aa315 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -582,32 +582,6 @@ static void free_arenas(struct btt *btt) } } -/* - * This function checks if the metadata layout is valid and error free - */ -static int arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super) -{ - u64 checksum; - - if (memcmp(super->uuid, nd_btt->uuid, 16)) - return 0; - - checksum = le64_to_cpu(super->checksum); - super->checksum = 0; - if (checksum != nd_btt_sb_checksum(super)) - return 0; - super->checksum = cpu_to_le64(checksum); - - if (nd_btt->lbasize != le32_to_cpu(super->external_lbasize)) - return 0; - - /* 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 1; -} - /* * This function reads an existing valid btt superblock and * populates the corresponding arena_info struct @@ -665,7 +639,7 @@ static int discover_arenas(struct btt *btt) if (ret) goto out; - if (!arena_is_valid(btt->nd_btt, super)) { + if (!nd_btt_arena_is_valid(btt->nd_btt, super)) { if (remaining == btt->rawsize) { btt->init_state = INIT_NOTFOUND; dev_info(to_dev(arena), "No existing arenas\n"); diff --git a/drivers/nvdimm/btt.h b/drivers/nvdimm/btt.h index 75b0d80a6bd9..b2f8651e5395 100644 --- a/drivers/nvdimm/btt.h +++ b/drivers/nvdimm/btt.h @@ -182,4 +182,7 @@ struct btt { int init_state; int num_arenas; }; + +bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); + #endif diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c index 6ac8c0fea3ec..18e0663e922c 100644 --- a/drivers/nvdimm/btt_devs.c +++ b/drivers/nvdimm/btt_devs.c @@ -342,6 +342,38 @@ struct device *nd_btt_create(struct nd_region *nd_region) return dev; } +/** + * 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 + * + * Check consistency of the btt info block with itself by validating + * the checksum. + * + * Returns: + * false for an invalid info block, true for a valid one + */ +bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super) +{ + u64 checksum; + + if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0) + return false; + + checksum = le64_to_cpu(super->checksum); + super->checksum = 0; + if (checksum != nd_btt_sb_checksum(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_arena_is_valid); + /* * nd_btt_sb_checksum: compute checksum for btt info block * @@ -364,8 +396,6 @@ EXPORT_SYMBOL(nd_btt_sb_checksum); 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 +405,8 @@ 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); -- 2.20.1