On Sun, 31 Jul 2022 at 21:34, Sam Li <faithilike...@gmail.com> wrote: > > Use sysfs attribute files to get the string value of device > zoned model. Then get_sysfs_zoned_model can convert it to > BlockZoneModel type in QEMU. > > Signed-off-by: Sam Li <faithilike...@gmail.com> > --- > block/file-posix.c | 86 ++++++++++++++++++++++++++++++++ > include/block/block_int-common.h | 3 ++ > 2 files changed, 89 insertions(+) > > diff --git a/block/file-posix.c b/block/file-posix.c > index bcf898f0cb..0d8b4acdc7 100644 > --- a/block/file-posix.c > +++ b/block/file-posix.c > @@ -1271,6 +1271,85 @@ out: > #endif > } > > +/* > + * Convert the zoned attribute file in sysfs to internal value. > + */ > +static int get_sysfs_str_val(int fd, struct stat *st, > + const char *attribute, > + char **val) { > +#ifdef CONFIG_LINUX > + char buf[32]; > + char *sysfspath = NULL;
This can be g_autofree and then the explicit g_free(sysfspath) call is no longer necessary. > + int ret, offset; > + int sysfd = -1; > + > + if (S_ISCHR(st->st_mode)) { > + if (ioctl(fd, SG_GET_SG_TABLESIZE, &ret) == 0) { > + return ret; > + } > + return -ENOTSUP; > + } This is for max_segments only. See my comment on the previous patch. > + > + 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); The code that follows can be replaced by a call to g_file_get_contents(): https://docs.gtk.org/glib/func.file_get_contents.html Then the caller doesn't need to pre-allocate a 32-byte buffer. Instead this function returns a string on the heap. The caller can free it with g_free(). > + sysfd = open(sysfspath, O_RDONLY); > + if (sysfd == -1) { > + ret = -errno; > + goto out; > + } > + offset = 0; > + do { > + ret = read(sysfd, buf + offset, sizeof(buf) - 1 + offset); > + if (ret > 0) { > + offset += ret; > + } > + } while (ret == -1); I think this should be: } while (ret == -1 && errno == EINTR); if (ret < 0) { ret = -errno; goto out; } Otherwise there is an infinite loop when an unrecoverable error occurs. > + /* The file is ended with '\n' */ > + if (buf[ret - 1] == '\n') { > + buf[ret - 1] = '\0'; > + } > + > + if (!strncpy(*val, buf, ret)) { > + goto out; > + } > + > +out: > + if (sysfd != -1) { > + close(sysfd); > + } > + g_free(sysfspath); > + return ret; > +#else > + return -ENOTSUP; > +#endif > +} > + > +static int get_sysfs_zoned_model(int fd, struct stat *st, > + BlockZoneModel *zoned) { > + g_autofree char *val = NULL; > + val = g_malloc(32); > + get_sysfs_str_val(fd, st, "zoned", &val); > + if (!val) { > + return -ENOTSUP; > + } > + > + 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; > +} > + > static int hdev_get_max_segments(int fd, struct stat *st) { > return get_sysfs_long_val(fd, st, "max_segments"); > } > @@ -1279,6 +1358,8 @@ 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); > @@ -1316,6 +1397,11 @@ static void raw_refresh_limits(BlockDriverState *bs, > Error **errp) > bs->bl.max_hw_iov = ret; > } > } > + > + ret = get_sysfs_zoned_model(s->fd, &st, &zoned); > + if (ret < 0) > + zoned = BLK_Z_NONE; QEMU coding style always uses {}: 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; > -- > 2.37.1 > >