diff mbox series

[v9,2/7] file-posix: introduce helper functions for sysfs attributes

Message ID 20220910052759.27517-3-faithilikerun@gmail.com (mailing list archive)
State New, archived
Headers show
Series Add support for zoned device | expand

Commit Message

Sam Li Sept. 10, 2022, 5:27 a.m. UTC 
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 <faithilikerun@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/file-posix.c               | 121 ++++++++++++++++++++++---------
 include/block/block_int-common.h |   3 +
 2 files changed, 88 insertions(+), 36 deletions(-)

Comments

Damien Le Moal Sept. 11, 2022, 4:56 a.m. UTC | #1 
On 2022/09/10 14:27, 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 <faithilikerun@gmail.com>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Looks good to me.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

> ---
>  block/file-posix.c               | 121 ++++++++++++++++++++++---------
>  include/block/block_int-common.h |   3 +
>  2 files changed, 88 insertions(+), 36 deletions(-)
> 
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 48cd096624..0a8b4b426e 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -1210,66 +1210,109 @@ 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, &ret) == 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, &len, 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", &val);
>      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, &end, 10, &max_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, &str);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    /* The file is ended with '\n', pass 'end' to accept that. */
> +    ret = qemu_strtol(str, &end, 10, &val);
> +    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, &ret) == 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);
> @@ -1307,6 +1350,12 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
>              bs->bl.max_hw_iov = ret;
>          }
>      }
> +
> +    ret = get_sysfs_zoned_model(&st, &zoned);
> +    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 */
>      int max_iov;
> +
> +    /* device zone model */
> +    BlockZoneModel zoned;
>  } BlockLimits;
>  
>  typedef struct BdrvOpBlocker BdrvOpBlocker;
diff mbox series

Patch

diff --git a/block/file-posix.c b/block/file-posix.c
index 48cd096624..0a8b4b426e 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1210,66 +1210,109 @@  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, &ret) == 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, &len, 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", &val);
     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, &end, 10, &max_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, &str);
+    if (ret < 0) {
+        return ret;
+    }
+
+    /* The file is ended with '\n', pass 'end' to accept that. */
+    ret = qemu_strtol(str, &end, 10, &val);
+    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, &ret) == 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);
@@ -1307,6 +1350,12 @@  static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
             bs->bl.max_hw_iov = ret;
         }
     }
+
+    ret = get_sysfs_zoned_model(&st, &zoned);
+    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 */
     int max_iov;
+
+    /* device zone model */
+    BlockZoneModel zoned;
 } BlockLimits;
 
 typedef struct BdrvOpBlocker BdrvOpBlocker;