The purpose of this patch is to recognize a zoned block device (ZBD)
when it is opened as a raw file. The new code initializes the zoned
model propery introduced by the previous commit.
This commit is Linux-specific as it gets the Zoned Block Device Model
value (none/host-managed/host-aware) from sysfs on the host.
In order to avoid code duplication in file-posix.c, a common helper
function is added to read values of sysfs entries under
/sys/block/<dev>/queue. This way, the existing function that reads
the value of "max_segments" entry and the the new function that reads
"zoned" value both share the same helper code.
Signed-off-by: Dmitry Fomichev <dmitry.fomic...@wdc.com>
---
block/file-posix.c | 75 ++++++++++++++++++++++++++++++++++++++--------
block/io.c | 5 ++++
2 files changed, 67 insertions(+), 13 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index fbeb0068db..c7e1aff6eb 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1067,15 +1067,13 @@ static int sg_get_max_transfer_length(int fd)
#endif
}
-static int sg_get_max_segments(int fd)
+static int hdev_read_blk_queue_entry(int fd, const char *key,
+ char *buf, int buf_len)
{
#ifdef CONFIG_LINUX
- char buf[32];
- const char *end;
char *sysfspath = NULL;
int ret;
int sysfd = -1;
- long max_segments;
struct stat st;
if (fstat(fd, &st)) {
@@ -1083,23 +1081,45 @@ static int sg_get_max_segments(int fd)
goto out;
}
- sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/max_segments",
- major(st.st_rdev), minor(st.st_rdev));
+ sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/%s",
+ major(st.st_rdev), minor(st.st_rdev), key);
sysfd = open(sysfspath, O_RDONLY);
if (sysfd == -1) {
ret = -errno;
goto out;
}
do {
- ret = read(sysfd, buf, sizeof(buf) - 1);
+ ret = read(sysfd, buf, buf_len - 1);
} while (ret == -1 && errno == EINTR);
if (ret < 0) {
ret = -errno;
- goto out;
} else if (ret == 0) {
ret = -EIO;
+ }
+out:
+ if (sysfd != -1) {
+ close(sysfd);
+ }
+ g_free(sysfspath);
+ return ret;
+#else
+ return -ENOTSUP;
+#endif
+}
+
+static int sg_get_max_segments(int fd)
+{
+#ifdef CONFIG_LINUX
+ char buf[32];
+ const char *end;
+ int ret;
+ long max_segments;
+
+ ret = hdev_read_blk_queue_entry(fd, "max_segments", buf, sizeof(buf));
+ if (ret < 0) {
goto out;
}
+
buf[ret] = 0;
/* The file is ended with '\n', pass 'end' to accept that. */
ret = qemu_strtol(buf, &end, 10, &max_segments);
@@ -1108,22 +1128,45 @@ static int sg_get_max_segments(int fd)
}
out:
- if (sysfd != -1) {
- close(sysfd);
- }
- g_free(sysfspath);
return ret;
#else
return -ENOTSUP;
#endif
}
+static BdrvZonedModel hdev_get_zoned_model(int fd)
+{
+#ifdef CONFIG_LINUX
+ char buf[32];
+ BdrvZonedModel zm = BDRV_ZONED_MODEL_NONE;
+ int ret;
+
+ ret = hdev_read_blk_queue_entry(fd, "zoned", buf, sizeof(buf));
+ if (ret < 0) {
+ goto out;
+ }
+
+ buf[ret - 1] = '\0'; /* replace the newline character with NULL */
+ if (strcmp(buf, "host-managed") == 0) {
+ zm = BDRV_ZONED_MODEL_HM;
+ } else if (strcmp(buf, "host-aware") == 0) {
+ zm = BDRV_ZONED_MODEL_HA;
+ }
+
+out:
+ return zm;
+#else
+ return BDRV_ZONED_MODEL_NONE;
+#endif
+}
+
static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVRawState *s = bs->opaque;
+ int ret;
if (bs->sg) {
- int ret = sg_get_max_transfer_length(s->fd);
+ ret = sg_get_max_transfer_length(s->fd);
if (ret > 0 && ret <= BDRV_REQUEST_MAX_BYTES) {
bs->bl.max_transfer = pow2floor(ret);
@@ -1133,6 +1176,12 @@ static void raw_refresh_limits(BlockDriverState *bs,
Error **errp)
if (ret > 0) {
bs->bl.max_transfer = MIN(bs->bl.max_transfer, ret *
getpagesize());
}
+
+ }
+
+ ret = hdev_get_zoned_model(s->fd);
+ if (ret >= 0) {
+ bs->bl.zoned_model = ret;
}
raw_probe_alignment(bs, s->fd, errp);
diff --git a/block/io.c b/block/io.c
index 0fa10831ed..147c320061 100644
--- a/block/io.c
+++ b/block/io.c
@@ -157,6 +157,11 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error
**errp)
return;
}
bdrv_merge_limits(&bs->bl, &bs->file->bs->bl);
+
+ /* Propagate zoned model */
+ if (!bs->probed) {
+ bs->bl.zoned_model = bs->file->bs->bl.zoned_model;
+ }
} else {
bs->bl.min_mem_alignment = 512;
bs->bl.opt_mem_alignment = getpagesize();
--
2.21.0
