| Message ID | 1437518265-14294-4-git-send-email-vishal.l.verma@intel.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Vishal Verma |
| Headers | show |
On Tue, Jul 21, 2015 at 3:37 PM, Vishal Verma <vishal.l.verma@intel.com> wrote: > 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 and parent_uuid are the necessary and > sufficient conditions to make sure a BTT is both, consistent with itself, > and not associated with a stale namespace. > > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> > --- > drivers/nvdimm/btt.c | 43 +----------------------------------- > drivers/nvdimm/btt.h | 3 +++ > drivers/nvdimm/btt_devs.c | 55 +++++++++++++++++++++++++++++++++++++++-------- > 3 files changed, 50 insertions(+), 51 deletions(-) > > diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c > index 81781db..1958829 100644 > --- a/drivers/nvdimm/btt.c > +++ b/drivers/nvdimm/btt.c > @@ -582,47 +582,6 @@ static void free_arenas(struct btt *btt) > } > } > > -static int uuid_is_null(u8 *uuid) > -{ > - static const u8 null_uuid[16]; > - > - return !memcmp(uuid, null_uuid, 16); > -} Hmm, changing code you just added is usually a sign the patch order is wrong. I think it makes sense to do the refactoring with no expected change in behavior, and then add the parent uuid checking. > - > -/* > - * 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) > -{ > - 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 0; > - > - if (memcmp(super->uuid, nd_btt->uuid, 16)) > - return 0; > - > - if (!uuid_is_null(super->parent_uuid)) > - if (memcmp(super->parent_uuid, parent_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 > @@ -680,7 +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 75b0d80..f2ac1bd 100644 > --- a/drivers/nvdimm/btt.h > +++ b/drivers/nvdimm/btt.h > @@ -182,4 +182,7 @@ struct btt { > int init_state; > int num_arenas; > }; > + > +int 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 6ac8c0f..4ad4de6 100644 > --- a/drivers/nvdimm/btt_devs.c > +++ b/drivers/nvdimm/btt_devs.c > @@ -342,6 +342,51 @@ struct device *nd_btt_create(struct nd_region *nd_region) > return dev; > } > > +static int uuid_is_null(u8 *uuid) > +{ > + static const u8 null_uuid[16]; > + > + return !memcmp(uuid, null_uuid, 16); > +} > + > +/** > + * 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, and with the parent namespace by verifying the > + * parent_uuid contained in the info block with the one supplied in. > + * > + * Returns: > + * 0 for an invalid info block, 1 for a valid one true / false for "is()" routines please. Outside of that, and the patch ordering, looks good.
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 81781db..1958829 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -582,47 +582,6 @@ static void free_arenas(struct btt *btt) } } -static int uuid_is_null(u8 *uuid) -{ - static const u8 null_uuid[16]; - - return !memcmp(uuid, null_uuid, 16); -} - -/* - * 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) -{ - 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 0; - - if (memcmp(super->uuid, nd_btt->uuid, 16)) - return 0; - - if (!uuid_is_null(super->parent_uuid)) - if (memcmp(super->parent_uuid, parent_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 @@ -680,7 +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 75b0d80..f2ac1bd 100644 --- a/drivers/nvdimm/btt.h +++ b/drivers/nvdimm/btt.h @@ -182,4 +182,7 @@ struct btt { int init_state; int num_arenas; }; + +int 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 6ac8c0f..4ad4de6 100644 --- a/drivers/nvdimm/btt_devs.c +++ b/drivers/nvdimm/btt_devs.c @@ -342,6 +342,51 @@ struct device *nd_btt_create(struct nd_region *nd_region) return dev; } +static int uuid_is_null(u8 *uuid) +{ + static const u8 null_uuid[16]; + + return !memcmp(uuid, null_uuid, 16); +} + +/** + * 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, and with the parent namespace by verifying the + * parent_uuid contained in the info block with the one supplied in. + * + * Returns: + * 0 for an invalid info block, 1 for a valid one + */ +int nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super) +{ + 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 0; + + if (!uuid_is_null(super->parent_uuid)) + if (memcmp(super->parent_uuid, parent_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); + + /* 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; +} +EXPORT_SYMBOL(nd_btt_arena_is_valid); + /* * nd_btt_sb_checksum: compute checksum for btt info block * @@ -364,8 +409,6 @@ 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 +418,8 @@ 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);
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 and parent_uuid are the necessary and sufficient conditions to make sure a BTT is both, consistent with itself, and not associated with a stale namespace. Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> --- drivers/nvdimm/btt.c | 43 +----------------------------------- drivers/nvdimm/btt.h | 3 +++ drivers/nvdimm/btt_devs.c | 55 +++++++++++++++++++++++++++++++++++++++-------- 3 files changed, 50 insertions(+), 51 deletions(-)