From d0ab0b1ab991f48fc1fb579490df397d5f819913 Mon Sep 17 00:00:00 2001 From: Hans Holmberg Date: Fri, 30 Mar 2018 00:04:51 +0200 Subject: [PATCH] lightnvm: pblk: check data lines version on recovery MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit As a preparation for future bumps of data line persistent storage versions, we need to start checking the emeta line version during recovery. Also slit up the current emeta/smeta version into two bytes (major,minor). Recovering lines with the same major number as the current pblk data line version must succeed. This means that any changes in the persistent format must be: (1) Backward compatible: if we switch back to and older kernel, recovery of lines stored with major == current_major and minor > current_minor must succeed. (2) Forward compatible: switching to a newer kernel, recovery of lines stored with major=current_major and minor < minor must handle the data format differences gracefully(i.e. initialize new data structures to default values). If we detect lines that have a different major number than the current we must abort recovery. The user must manually migrate the data in this case. Previously the version stored in the emeta header was copied from smeta, which has version 1, so we need to set the minor version to 1. Signed-off-by: Hans Holmberg Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- drivers/lightnvm/pblk-core.c | 9 ++++++++- drivers/lightnvm/pblk-recovery.c | 26 ++++++++++++++++++++++++-- drivers/lightnvm/pblk.h | 16 ++++++++++++++-- 3 files changed, 46 insertions(+), 5 deletions(-) diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c index 9027cf2e..155e42a 100644 --- a/drivers/lightnvm/pblk-core.c +++ b/drivers/lightnvm/pblk-core.c @@ -975,7 +975,8 @@ static int pblk_line_init_metadata(struct pblk *pblk, struct pblk_line *line, memcpy(smeta_buf->header.uuid, pblk->instance_uuid, 16); smeta_buf->header.id = cpu_to_le32(line->id); smeta_buf->header.type = cpu_to_le16(line->type); - smeta_buf->header.version = SMETA_VERSION; + smeta_buf->header.version_major = SMETA_VERSION_MAJOR; + smeta_buf->header.version_minor = SMETA_VERSION_MINOR; /* Start metadata */ smeta_buf->seq_nr = cpu_to_le64(line->seq_nr); @@ -998,6 +999,12 @@ static int pblk_line_init_metadata(struct pblk *pblk, struct pblk_line *line, /* End metadata */ memcpy(&emeta_buf->header, &smeta_buf->header, sizeof(struct line_header)); + + emeta_buf->header.version_major = EMETA_VERSION_MAJOR; + emeta_buf->header.version_minor = EMETA_VERSION_MINOR; + emeta_buf->header.crc = cpu_to_le32( + pblk_calc_meta_header_crc(pblk, &emeta_buf->header)); + emeta_buf->seq_nr = cpu_to_le64(line->seq_nr); emeta_buf->nr_lbas = cpu_to_le64(line->sec_in_line); emeta_buf->nr_valid_lbas = cpu_to_le64(0); diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c index 1d5e961..a30fe20 100644 --- a/drivers/lightnvm/pblk-recovery.c +++ b/drivers/lightnvm/pblk-recovery.c @@ -826,6 +826,25 @@ static u64 pblk_line_emeta_start(struct pblk *pblk, struct pblk_line *line) return emeta_start; } +static int pblk_recov_check_line_version(struct pblk *pblk, + struct line_emeta *emeta) +{ + struct line_header *header = &emeta->header; + + if (header->version_major != EMETA_VERSION_MAJOR) { + pr_err("pblk: line major version mismatch: %d, expected: %d\n", + header->version_major, EMETA_VERSION_MAJOR); + return 1; + } + +#ifdef NVM_DEBUG + if (header->version_minor > EMETA_VERSION_MINOR) + pr_info("pblk: newer line minor version found: %d\n", line_v); +#endif + + return 0; +} + struct pblk_line *pblk_recov_l2p(struct pblk *pblk) { struct pblk_line_meta *lm = &pblk->lm; @@ -873,9 +892,9 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk) if (le32_to_cpu(smeta_buf->header.identifier) != PBLK_MAGIC) continue; - if (smeta_buf->header.version != SMETA_VERSION) { + if (smeta_buf->header.version_major != SMETA_VERSION_MAJOR) { pr_err("pblk: found incompatible line version %u\n", - le16_to_cpu(smeta_buf->header.version)); + smeta_buf->header.version_major); return ERR_PTR(-EINVAL); } @@ -943,6 +962,9 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk) goto next; } + if (pblk_recov_check_line_version(pblk, line->emeta->buf)) + return ERR_PTR(-EINVAL); + if (pblk_recov_l2p_from_emeta(pblk, line)) pblk_recov_l2p_from_oob(pblk, line); diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h index 8c357fb..fae2526 100644 --- a/drivers/lightnvm/pblk.h +++ b/drivers/lightnvm/pblk.h @@ -320,14 +320,26 @@ enum { }; #define PBLK_MAGIC 0x70626c6b /*pblk*/ -#define SMETA_VERSION cpu_to_le16(1) + +/* emeta/smeta persistent storage format versions: + * Changes in major version requires offline migration. + * Changes in minor version are handled automatically during + * recovery. + */ + +#define SMETA_VERSION_MAJOR (0) +#define SMETA_VERSION_MINOR (1) + +#define EMETA_VERSION_MAJOR (0) +#define EMETA_VERSION_MINOR (1) struct line_header { __le32 crc; __le32 identifier; /* pblk identifier */ __u8 uuid[16]; /* instance uuid */ __le16 type; /* line type */ - __le16 version; /* type version */ + __u8 version_major; /* version major */ + __u8 version_minor; /* version minor */ __le32 id; /* line id for current line */ }; -- 2.7.4