| Message ID | 20200513213621.470411-8-tasleson@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add persistent durable identifier to storage log messages | expand |
On Wed, May 13, 2020 at 04:36:21PM -0500, Tony Asleson wrote: > +static int dev_to_nvme_durable_name(const struct device *dev, char *buf, size_t len) > +{ > + char serial[128]; > + ssize_t serial_len = wwid_show((struct device *)dev, NULL, serial); wwid_show() can generate a serial larger than 128 bytes. > + > + if (serial_len > 0 && serial_len < len) { > + serial_len -= 1; // Remove the '\n' from the string Comments in this driver should use the /* */ style. > + strncpy(buf, serial, serial_len); > + return serial_len; > + } > + return 0; > +}
On 5/13/20 6:04 PM, Keith Busch wrote: > On Wed, May 13, 2020 at 04:36:21PM -0500, Tony Asleson wrote: >> +static int dev_to_nvme_durable_name(const struct device *dev, char *buf, size_t len) >> +{ >> + char serial[128]; >> + ssize_t serial_len = wwid_show((struct device *)dev, NULL, serial); > > wwid_show() can generate a serial larger than 128 bytes. Looking at this again return sprintf(buf, "nvme.%04x-%*phN-%*phN-%08x\n", subsys->vendor_id, serial_len, subsys->serial, model_len, subsys->model, subsys->ns_id); 'nvme.' = 5 vendor_id = 4 '-' = 1 serial (20 * 2) = 40 '-' = 1 model (40 * 2) = 80 '-' = 1 ns_id = 8 '\n' = 1 5 + 4 + 1 + 40 + 1 + 80 + 1 + 8 + 1 = 141 Does this match your understanding? My mistake was thinking each byte of SN and Model = 1 character in output, instead of 2. This will also require the buffer used in dev_vprintk_emit to be quite a bit bigger to accommodate max size. >> + >> + if (serial_len > 0 && serial_len < len) { >> + serial_len -= 1; // Remove the '\n' from the string > > Comments in this driver should use the /* */ style. OK, will revise. > >> + strncpy(buf, serial, serial_len); >> + return serial_len; >> + } >> + return 0; >> +} > Thanks -Tony
On Thu, May 14, 2020 at 12:13:36PM -0500, Tony Asleson wrote: > On 5/13/20 6:04 PM, Keith Busch wrote: > > On Wed, May 13, 2020 at 04:36:21PM -0500, Tony Asleson wrote: > >> +static int dev_to_nvme_durable_name(const struct device *dev, char *buf, size_t len) > >> +{ > >> + char serial[128]; > >> + ssize_t serial_len = wwid_show((struct device *)dev, NULL, serial); > > > > wwid_show() can generate a serial larger than 128 bytes. > > Looking at this again > > return sprintf(buf, "nvme.%04x-%*phN-%*phN-%08x\n", > subsys->vendor_id, > serial_len, subsys->serial, > model_len, subsys->model, > subsys->ns_id); > > 'nvme.' = 5 > vendor_id = 4 > '-' = 1 > serial (20 * 2) = 40 > '-' = 1 > model (40 * 2) = 80 > '-' = 1 > ns_id = 8 > '\n' = 1 > > 5 + 4 + 1 + 40 + 1 + 80 + 1 + 8 + 1 = 141 > > Does this match your understanding? Yep, that looks like the correct max possible length. I didn't actually count it out, but I just knew it could be larger than 128. :)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index a4d8c90ee7cc..7479c7e82200 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2614,6 +2614,22 @@ static bool nvme_validate_cntlid(struct nvme_subsystem *subsys, return true; } +static ssize_t wwid_show(struct device *dev, struct device_attribute *attr, + char *buf); + +static int dev_to_nvme_durable_name(const struct device *dev, char *buf, size_t len) +{ + char serial[128]; + ssize_t serial_len = wwid_show((struct device *)dev, NULL, serial); + + if (serial_len > 0 && serial_len < len) { + serial_len -= 1; // Remove the '\n' from the string + strncpy(buf, serial, serial_len); + return serial_len; + } + return 0; +} + static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) { struct nvme_subsystem *subsys, *found; @@ -3541,6 +3557,8 @@ static int nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) disk->queue = ns->queue; disk->flags = flags; memcpy(disk->disk_name, disk_name, DISK_NAME_LEN); + disk_to_dev(disk)->durable_name = dev_to_nvme_durable_name; + ns->disk = disk; __nvme_revalidate_disk(disk, id);
Signed-off-by: Tony Asleson <tasleson@redhat.com> --- drivers/nvme/host/core.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)