[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 2/4] raw: Recognize zoned backing devices
From: |
Dmitry Fomichev |
Subject: |
[Qemu-devel] [PATCH 2/4] raw: Recognize zoned backing devices |
Date: |
Tue, 9 Jul 2019 16:38:04 -0400 |
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 and in essence it checks the Zoned
Block Device Model (None/Host-managed/Host-aware) value in sysfs on
the host.
In order to avoid code duplication in file-posix.c, a common helper
function is added to read value of a sysfs entry under
/sys/block/<dev>/queue. Now, the existing function that reads the
"max_segments" value and the the new function that reads "zoned"
value share the same helper code.
Signed-off-by: Dmitry Fomichev <address@hidden>
---
block/file-posix.c | 69 ++++++++++++++++++++++++++++++++++++++--------
block/raw-format.c | 8 ++++++
2 files changed, 66 insertions(+), 11 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index ab05b51a66..dd81dc3301 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1055,33 +1055,53 @@ static int
hdev_get_max_transfer_length(BlockDriverState *bs, int fd)
#endif
}
-static int hdev_get_max_segments(const struct stat *st)
+static int hdev_read_blk_queue_entry(const struct stat *st, const char *key,
+ char *buf, int buf_len)
{
#ifdef CONFIG_LINUX
- char buf[32];
- const char *end;
char *sysfspath;
int ret;
int fd = -1;
- long max_segments;
- 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);
fd = open(sysfspath, O_RDONLY);
if (fd == -1) {
ret = -errno;
goto out;
}
do {
- ret = read(fd, buf, sizeof(buf) - 1);
+ ret = read(fd, buf, buf_len - 1);
} while (ret == -1 && errno == EINTR);
if (ret < 0) {
ret = -errno;
- goto out;
} else if (ret == 0) {
ret = -EIO;
+ }
+out:
+ if (fd != -1) {
+ close(fd);
+ }
+ g_free(sysfspath);
+ return ret;
+#else
+ return -ENOTSUP;
+#endif
+}
+
+static int hdev_get_max_segments(const struct stat *st)
+{
+#ifdef CONFIG_LINUX
+ char buf[32];
+ const char *end;
+ int ret;
+ long max_segments;
+
+ ret = hdev_read_blk_queue_entry(st, "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);
@@ -1090,10 +1110,33 @@ static int hdev_get_max_segments(const struct stat *st)
}
out:
- if (fd != -1) {
- close(fd);
+ return ret;
+#else
+ return -ENOTSUP;
+#endif
+}
+
+static int hdev_get_zoned_model(const struct stat *st)
+{
+#ifdef CONFIG_LINUX
+ char buf[32];
+ int ret;
+
+ ret = hdev_read_blk_queue_entry(st, "zoned", buf, sizeof(buf));
+ if (ret < 0) {
+ ret = BLK_ZONED_NONE;
+ goto out;
}
- g_free(sysfspath);
+
+ buf[ret - 1] = 0;
+ ret = BLK_ZONED_NONE;
+ if (strcmp(buf, "host-managed") == 0) {
+ ret = BLK_ZONED_HM;
+ } else if (strcmp(buf, "host-aware") == 0) {
+ ret = BLK_ZONED_HA;
+ }
+
+out:
return ret;
#else
return -ENOTSUP;
@@ -1116,6 +1159,10 @@ static void raw_refresh_limits(BlockDriverState *bs,
Error **errp)
bs->bl.max_transfer = MIN(bs->bl.max_transfer,
ret * getpagesize());
}
+ ret = hdev_get_zoned_model(&st);
+ if (ret >= 0) {
+ bs->bl.zoned_model = ret;
+ }
}
}
diff --git a/block/raw-format.c b/block/raw-format.c
index bffd424dd0..12c2a3f95d 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -369,6 +369,13 @@ static void raw_refresh_limits(BlockDriverState *bs, Error
**errp)
}
}
+static void raw_get_zoned_info(BlockDriverState *bs)
+{
+ if (!bs->probed) {
+ bs->bl.zoned_model = bs->file->bs->bl.zoned_model;
+ }
+}
+
static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
PreallocMode prealloc, Error **errp)
{
@@ -572,6 +579,7 @@ BlockDriver bdrv_raw = {
.bdrv_co_ioctl = &raw_co_ioctl,
.create_opts = &raw_create_opts,
.bdrv_has_zero_init = &raw_has_zero_init,
+ .bdrv_get_zoned_info = &raw_get_zoned_info,
.strong_runtime_opts = raw_strong_runtime_opts,
.mutable_opts = mutable_opts,
};
--
2.21.0