From d0ab0b1ab991f48fc1fb579490df397d5f819913 Mon Sep 17 00:00:00 2001 From: Hans Holmberg Date: Fri, 30 Mar 2018 00:04:51 +0200 Subject: lightnvm: pblk: check data lines version on recovery MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/lightnvm/pblk-core.c') diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c index 9027cf2ed1d8..155e42a26293 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); -- cgit v1.2.3