create-ns: align the namespaces to 1Mib boundaries when using SI suffixes

Documentation/nvme-create-ns.txt

@@ -98,13 +98,15 @@ OPTIONS
 
 -S::
 --nsze-si::
-	The namespace size (NSZE) in standard SI units.
+	The namespace size (NSZE) in standard SI units (aligned on 1Mib boundaries,
+	unless the controller recommends a smaller value).
 	The value SI suffixed is divided by the namespace LBA size to set as NSZE.
 	If the value not suffixed it is set as same with the nsze option.
 
 -C::
 --ncap-si::
-	The namespace capacity (NCAP) in standard SI units.
+	The namespace capacity (NCAP) in standard SI units (aligned on 1Mib boundaries,
+	unless the controller recommends a smaller value).
 	The value SI suffixed is divided by the namespace LBA size to set as NCAP.
 	If the value not suffixed it is set as same with the ncap option.
 
@@ -155,4 +157,4 @@ EXAMPLES
 
 NVME
 ----
-Part of the nvme-user suite
+Part of the nvme-user suite

nvme.c

@@ -2833,12 +2833,13 @@ static int detach_ns(int argc, char **argv, struct command *cmd, struct plugin *
 }
 
 static int parse_lba_num_si(struct nvme_dev *dev, const char *opt,
-			    const char *val, __u8 flbas, __u64 *num)
+			    const char *val, __u8 flbas, __u64 *num, __u32 align)
 {
 	_cleanup_free_ struct nvme_ns_list *ns_list = NULL;
 	_cleanup_free_ struct nvme_id_ctrl *ctrl = NULL;
 	_cleanup_free_ struct nvme_id_ns *ns = NULL;
 	__u32 nsid = 1;
+	unsigned int remainder;
 	char *endptr;
 	int err = -EINVAL;
 	int i;
@@ -2916,6 +2917,12 @@ static int parse_lba_num_si(struct nvme_dev *dev, const char *opt,
 		return -errno;
 	}
 
+	if (endptr[0]) {
+		remainder = *num % align;
+		if (remainder)
+			*num += align - remainder;
+	}
+
 	if (endptr[0] != '\0')
 		*num /= lbas;
 
@@ -2958,6 +2965,10 @@ static int create_ns(int argc, char **argv, struct command *cmd, struct plugin *
 	__u32 nsid;
 	uint16_t num_phandle;
 	uint16_t phndl[128] = { 0, };
+	_cleanup_free_ struct nvme_id_ctrl *id = NULL;
+	_cleanup_free_ struct nvme_id_ns_granularity_list *gr_list = NULL;
+	__u32 align_nsze = 1 << 20; /* Default 1 MiB */
+	__u32 align_ncap = align_nsze;
 
 	struct config {
 		__u64	nsze;
@@ -3075,11 +3086,56 @@ static int create_ns(int argc, char **argv, struct command *cmd, struct plugin *
 		return -EINVAL;
 	}
 
-	err = parse_lba_num_si(dev, "nsze", cfg.nsze_si, cfg.flbas, &cfg.nsze);
+	id = nvme_alloc(sizeof(*id));
+	if (!id)
+		return -ENOMEM;
+
+	err = nvme_identify_ctrl(dev_fd(dev), id);
+	if (err) {
+		if (err < 0) {
+			nvme_show_error("identify-controller: %s", nvme_strerror(errno));
+		} else {
+			fprintf(stderr, "identify controller failed\n");
+			nvme_show_status(err);
+		}
+		return err;
+	}
+
+	if (id->ctratt & NVME_CTRL_CTRATT_NAMESPACE_GRANULARITY) {
+		gr_list = nvme_alloc(sizeof(*gr_list));
+		if (!gr_list)
+			return -ENOMEM;
+
+		if (!nvme_identify_ns_granularity(dev_fd(dev), gr_list)) {
+			struct nvme_id_ns_granularity_desc *desc;
+			int index = cfg.flbas;
+
+			/* FIXME: add a proper bitmask to libnvme */
+			if (!(gr_list->attributes & 1)) {
+				/* Only the first descriptor is valid */
+				index = 0;
+			} else if (index > gr_list->num_descriptors) {
+				/*
+				 * The descriptor will contain only zeroes
+				 * so we don't need to read it.
+				 */
+				goto parse_lba;
+			}
+			desc = &gr_list->entry[index];
+
+			if (desc->nszegran && desc->nszegran < align_nsze)
+				align_nsze = desc->nszegran;
+			if (desc->ncapgran && desc->ncapgran < align_ncap)
+				align_ncap = desc->ncapgran;
+		}
+	}
+
+parse_lba:
+	err = parse_lba_num_si(dev, "nsze", cfg.nsze_si, cfg.flbas, &cfg.nsze, align_nsze);
 	if (err)
 		return err;
 
-	err = parse_lba_num_si(dev, "ncap", cfg.ncap_si, cfg.flbas, &cfg.ncap);
+	err = parse_lba_num_si(dev, "ncap", cfg.ncap_si, cfg.flbas, &cfg.ncap, align_ncap);
 	if (err)
 		return err;