Re: [PATCH v12 2/7] file-posix: introduce helper functions for sysfs attributes
On Sun, 2022-10-16 at 22:51 +0800, Sam Li wrote:
> Use get_sysfs_str_val() to get the string value of device
> zoned model. Then get_sysfs_zoned_model() can convert it to
> BlockZoneModel type of QEMU.
>
> Use get_sysfs_long_val() to get the long value of zoned device
> information.
>
> Signed-off-by: Sam Li
> Reviewed-by: Hannes Reinecke
> Reviewed-by: Stefan Hajnoczi
> Reviewed-by: Damien Le Moal
Reviewed-by: Dmitry Fomichev
> ---
> block/file-posix.c | 124 ++-
> include/block/block_int-common.h | 3 +
> 2 files changed, 91 insertions(+), 36 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 23acffb9a4..8cb07fdb8a 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -1201,66 +1201,112 @@ static int hdev_get_max_hw_transfer(int fd, struct
> stat *st)
> #endif
> }
>
> -static int hdev_get_max_segments(int fd, struct stat *st)
> -{
> +/*
> + * Get a sysfs attribute value as character string.
> + */
> +static int get_sysfs_str_val(struct stat *st, const char *attribute,
> + char **val) {
> #ifdef CONFIG_LINUX
> - char buf[32];
> - const char *end;
> - char *sysfspath = NULL;
> + g_autofree char *sysfspath = NULL;
> int ret;
> - int sysfd = -1;
> - long max_segments;
> + size_t len;
>
> - if (S_ISCHR(st->st_mode)) {
> - if (ioctl(fd, SG_GET_SG_TABLESIZE, ) == 0) {
> - return ret;
> - }
> + if (!S_ISBLK(st->st_mode)) {
> return -ENOTSUP;
> }
>
> - if (!S_ISBLK(st->st_mode)) {
> - return -ENOTSUP;
> + sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/%s",
> + major(st->st_rdev), minor(st->st_rdev),
> + attribute);
> + ret = g_file_get_contents(sysfspath, val, , NULL);
> + if (ret == -1) {
> + return -ENOENT;
> }
>
> - sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/max_segments",
> - major(st->st_rdev), minor(st->st_rdev));
> - sysfd = open(sysfspath, O_RDONLY);
> - if (sysfd == -1) {
> - ret = -errno;
> - goto out;
> + /* The file is ended with '\n' */
> + char *p;
> + p = *val;
> + if (*(p + len - 1) == '\n') {
> + *(p + len - 1) = '\0';
> }
> - do {
> - ret = read(sysfd, buf, sizeof(buf) - 1);
> - } while (ret == -1 && errno == EINTR);
> + return ret;
> +#else
> + return -ENOTSUP;
> +#endif
> +}
> +
> +static int get_sysfs_zoned_model(struct stat *st, BlockZoneModel *zoned)
> +{
> + g_autofree char *val = NULL;
> + int ret;
> +
> + ret = get_sysfs_str_val(st, "zoned", );
> if (ret < 0) {
> - ret = -errno;
> - goto out;
> - } else if (ret == 0) {
> - ret = -EIO;
> - goto out;
> + return ret;
> }
> - buf[ret] = 0;
> - /* The file is ended with '\n', pass 'end' to accept that. */
> - ret = qemu_strtol(buf, , 10, _segments);
> - if (ret == 0 && end && *end == '\n') {
> - ret = max_segments;
> +
> + if (strcmp(val, "host-managed") == 0) {
> + *zoned = BLK_Z_HM;
> + } else if (strcmp(val, "host-aware") == 0) {
> + *zoned = BLK_Z_HA;
> + } else if (strcmp(val, "none") == 0) {
> + *zoned = BLK_Z_NONE;
> + } else {
> + return -ENOTSUP;
> }
> + return 0;
> +}
>
> -out:
> - if (sysfd != -1) {
> - close(sysfd);
> +/*
> + * Get a sysfs attribute value as a long integer.
> + */
> +static long get_sysfs_long_val(struct stat *st, const char *attribute)
> +{
> +#ifdef CONFIG_LINUX
> + g_autofree char *str = NULL;
> + const char *end;
> + long val;
> + int ret;
> +
> + ret = get_sysfs_str_val(st, attribute, );
> + if (ret < 0) {
> + return ret;
> + }
> +
> + /* The file is ended with '\n', pass 'end' to accept that. */
> + ret = qemu_strtol(str, , 10, );
> + if (ret == 0 && end && *end == '\0') {
> + ret = val;
> }
> - g_free(sysfspath);
> return ret;
> #else
> return -ENOTSUP;
> #endif
> }
>
> +static int hdev_get_max_segments(int fd, struct stat *st)
> +{
> +#ifdef CONFIG_LINUX
> + int ret;
> +
> + if (S_ISCHR(st->st_mode)) {
> + if (ioctl(fd, SG_GET_SG_TABLESIZE, ) == 0) {
> + return ret;
> + }
> + return -ENOTSUP;
> + }
> + return get_sysfs_long_val(st, "max_segments");
> +#else
> + return -ENOTSUP;
> +#endif
> +}
> +
> static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
> {
> BDRVRawState *s = bs->opaque;
> struct stat st;
> + int ret;
> + BlockZoneModel zoned;
>
> s->needs_alignment = raw_needs_alignment(bs);
> raw_probe_alignment(bs, s->fd, errp);
> @@ -1298,6 +1344,12 @@ static void raw_refresh_limits(BlockDriverState *bs,
> Error **errp)
> bs->bl.max_hw_iov = ret;
> }
> }
> +
> + ret =
[PATCH v12 2/7] file-posix: introduce helper functions for sysfs attributes
Use get_sysfs_str_val() to get the string value of device
zoned model. Then get_sysfs_zoned_model() can convert it to
BlockZoneModel type of QEMU.
Use get_sysfs_long_val() to get the long value of zoned device
information.
Signed-off-by: Sam Li
Reviewed-by: Hannes Reinecke
Reviewed-by: Stefan Hajnoczi
Reviewed-by: Damien Le Moal
---
block/file-posix.c | 124 ++-
include/block/block_int-common.h | 3 +
2 files changed, 91 insertions(+), 36 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index 23acffb9a4..8cb07fdb8a 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1201,66 +1201,112 @@ static int hdev_get_max_hw_transfer(int fd, struct
stat *st)
#endif
}
-static int hdev_get_max_segments(int fd, struct stat *st)
-{
+/*
+ * Get a sysfs attribute value as character string.
+ */
+static int get_sysfs_str_val(struct stat *st, const char *attribute,
+ char **val) {
#ifdef CONFIG_LINUX
-char buf[32];
-const char *end;
-char *sysfspath = NULL;
+g_autofree char *sysfspath = NULL;
int ret;
-int sysfd = -1;
-long max_segments;
+size_t len;
-if (S_ISCHR(st->st_mode)) {
-if (ioctl(fd, SG_GET_SG_TABLESIZE, ) == 0) {
-return ret;
-}
+if (!S_ISBLK(st->st_mode)) {
return -ENOTSUP;
}
-if (!S_ISBLK(st->st_mode)) {
-return -ENOTSUP;
+sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/%s",
+major(st->st_rdev), minor(st->st_rdev),
+attribute);
+ret = g_file_get_contents(sysfspath, val, , NULL);
+if (ret == -1) {
+return -ENOENT;
}
-sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/max_segments",
-major(st->st_rdev), minor(st->st_rdev));
-sysfd = open(sysfspath, O_RDONLY);
-if (sysfd == -1) {
-ret = -errno;
-goto out;
+/* The file is ended with '\n' */
+char *p;
+p = *val;
+if (*(p + len - 1) == '\n') {
+*(p + len - 1) = '\0';
}
-do {
-ret = read(sysfd, buf, sizeof(buf) - 1);
-} while (ret == -1 && errno == EINTR);
+return ret;
+#else
+return -ENOTSUP;
+#endif
+}
+
+static int get_sysfs_zoned_model(struct stat *st, BlockZoneModel *zoned)
+{
+g_autofree char *val = NULL;
+int ret;
+
+ret = get_sysfs_str_val(st, "zoned", );
if (ret < 0) {
-ret = -errno;
-goto out;
-} else if (ret == 0) {
-ret = -EIO;
-goto out;
+return ret;
}
-buf[ret] = 0;
-/* The file is ended with '\n', pass 'end' to accept that. */
-ret = qemu_strtol(buf, , 10, _segments);
-if (ret == 0 && end && *end == '\n') {
-ret = max_segments;
+
+if (strcmp(val, "host-managed") == 0) {
+*zoned = BLK_Z_HM;
+} else if (strcmp(val, "host-aware") == 0) {
+*zoned = BLK_Z_HA;
+} else if (strcmp(val, "none") == 0) {
+*zoned = BLK_Z_NONE;
+} else {
+return -ENOTSUP;
}
+return 0;
+}
-out:
-if (sysfd != -1) {
-close(sysfd);
+/*
+ * Get a sysfs attribute value as a long integer.
+ */
+static long get_sysfs_long_val(struct stat *st, const char *attribute)
+{
+#ifdef CONFIG_LINUX
+g_autofree char *str = NULL;
+const char *end;
+long val;
+int ret;
+
+ret = get_sysfs_str_val(st, attribute, );
+if (ret < 0) {
+return ret;
+}
+
+/* The file is ended with '\n', pass 'end' to accept that. */
+ret = qemu_strtol(str, , 10, );
+if (ret == 0 && end && *end == '\0') {
+ret = val;
}
-g_free(sysfspath);
return ret;
#else
return -ENOTSUP;
#endif
}
+static int hdev_get_max_segments(int fd, struct stat *st)
+{
+#ifdef CONFIG_LINUX
+int ret;
+
+if (S_ISCHR(st->st_mode)) {
+if (ioctl(fd, SG_GET_SG_TABLESIZE, ) == 0) {
+return ret;
+}
+return -ENOTSUP;
+}
+return get_sysfs_long_val(st, "max_segments");
+#else
+return -ENOTSUP;
+#endif
+}
+
static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVRawState *s = bs->opaque;
struct stat st;
+int ret;
+BlockZoneModel zoned;
s->needs_alignment = raw_needs_alignment(bs);
raw_probe_alignment(bs, s->fd, errp);
@@ -1298,6 +1344,12 @@ static void raw_refresh_limits(BlockDriverState *bs,
Error **errp)
bs->bl.max_hw_iov = ret;
}
}
+
+ret = get_sysfs_zoned_model(, );
+if (ret < 0) {
+zoned = BLK_Z_NONE;
+}
+bs->bl.zoned = zoned;
}
static int check_for_dasd(int fd)
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 8947abab76..7f7863cc9e 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -825,6 +825,9 @@ typedef struct BlockLimits {
/* maximum number of iovec elements */
