From: Sam Li <faithilikerun@gmail.com>
To: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: "Stefan Hajnoczi" <stefanha@redhat.com>,
qemu-devel@nongnu.org, "Richard Henderson" <rth@twiddle.net>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Thomas Huth" <thuth@redhat.com>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Julia Suvorova" <jusual@redhat.com>,
"Aarushi Mehta" <mehta.aaru20@gmail.com>,
"Kevin Wolf" <kwolf@redhat.com>,
kvm@vger.kernel.org,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Markus Armbruster" <armbru@redhat.com>,
"Cornelia Huck" <cohuck@redhat.com>,
"Raphael Norwitz" <raphael.norwitz@nutanix.com>,
qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
"Hanna Reitz" <hreitz@redhat.com>,
"Eric Blake" <eblake@redhat.com>,
"Stefano Garzarella" <sgarzare@redhat.com>,
"Fam Zheng" <fam@euphon.net>, "Hannes Reinecke" <hare@suse.de>,
"Damien Le Moal" <damien.lemoal@opensource.wdc.com>,
"Dmitry Fomichev" <dmitry.fomichev@wdc.com>
Subject: Re: [PULL v2 02/16] block/file-posix: introduce helper functions for sysfs attributes
Date: Sat, 3 Jun 2023 02:18:27 +0800 [thread overview]
Message-ID: <CAAAx-8Km7J8dfz_63y1W5wE8MH7hJXo04ajY1A-ctv--x9CpGA@mail.gmail.com> (raw)
In-Reply-To: <8b0ced3c-2fb5-2479-fe78-f4956ac037a6@linux.ibm.com>
Matthew Rosato <mjrosato@linux.ibm.com> 于2023年6月1日周四 02:21写道：
>
> On 5/15/23 12:04 PM, Stefan Hajnoczi wrote:
> > From: Sam Li <faithilikerun@gmail.com>
> >
> > 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.
>
> Hi Stefan, Sam,
>
> I am having an issue on s390x using virtio-blk-{pci,ccw} backed by an NVMe partition, and I've bisected the root cause to this commit.
>
> I noticed that tests which use the partition e.g. /dev/nvme0n1p1 as a backing device would fail, but those that use the namespace e.g. /dev/nvme0n1 would still succeed. The root issue appears to be that the block device associated with the partition does not have a "max_segments" attribute, and prior to this patch hdev_get_max_segment() would return -ENOENT in this case. After this patch, however, QEMU is instead crashing. It looks like g_file_get_contents is returning 0 with a len == 0 if the specified sysfs path does not exist. The following diff on top seems to resolve the issue for me:
>
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 0ab158efba2..eeb0247c74e 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -1243,7 +1243,7 @@ static int get_sysfs_str_val(struct stat *st, const char *attribute,
> major(st->st_rdev), minor(st->st_rdev),
> attribute);
> ret = g_file_get_contents(sysfspath, val, &len, NULL);
> - if (ret == -1) {
> + if (ret == -1 || len == 0) {
> return -ENOENT;
> }
>
Hi Matthew,
Thanks for the information. After some checking, I think the bug here
is that g_file_get_contens returns g_boolean value and the error case
will return 0 instead of -1 in my previous code. Can the following
line fix your issue on the s390x device?
+ if (ret == FALSE) {
https://docs.gtk.org/glib/func.file_get_contents.html
Thanks,
Sam
>
>
>
> >
> > Signed-off-by: Sam Li <faithilikerun@gmail.com>
> > Reviewed-by: Hannes Reinecke <hare@suse.de>
> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> > Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
> > Acked-by: Kevin Wolf <kwolf@redhat.com>
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Message-id: 20230508045533.175575-3-faithilikerun@gmail.com
> > Message-id: 20230324090605.28361-3-faithilikerun@gmail.com
> > [Adjust commit message prefix as suggested by Philippe Mathieu-Daudé
> > <philmd@linaro.org>.
> > --Stefan]
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> > include/block/block_int-common.h | 3 +
> > block/file-posix.c | 135 ++++++++++++++++++++++---------
> > 2 files changed, 100 insertions(+), 38 deletions(-)
> >
> > diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
> > index 4909876756..c7ca5a83e9 100644
> > --- a/include/block/block_int-common.h
> > +++ b/include/block/block_int-common.h
> > @@ -862,6 +862,9 @@ typedef struct BlockLimits {
> > * an explicit monitor command to load the disk inside the guest).
> > */
> > bool has_variable_length;
> > +
> > + /* device zone model */
> > + BlockZoneModel zoned;
> > } BlockLimits;
> >
> > typedef struct BdrvOpBlocker BdrvOpBlocker;
> > diff --git a/block/file-posix.c b/block/file-posix.c
> > index c7b723368e..97c597a2a0 100644
> > --- a/block/file-posix.c
> > +++ b/block/file-posix.c
> > @@ -1202,15 +1202,89 @@ 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.
> > + */
> > +#ifdef CONFIG_LINUX
> > +static int get_sysfs_str_val(struct stat *st, const char *attribute,
> > + char **val) {
> > + g_autofree char *sysfspath = NULL;
> > + int ret;
> > + size_t len;
> > +
> > + 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;
> > + }
> > +
> > + /* The file is ended with '\n' */
> > + char *p;
> > + p = *val;
> > + if (*(p + len - 1) == '\n') {
> > + *(p + len - 1) = '\0';
> > + }
> > + return ret;
> > +}
> > +#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) {
> > + return ret;
> > + }
> > +
> > + 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;
> > +}
> > +
> > +/*
> > + * Get a sysfs attribute value as a long integer.
> > + */
> > #ifdef CONFIG_LINUX
> > - char buf[32];
> > +static long get_sysfs_long_val(struct stat *st, const char *attribute)
> > +{
> > + g_autofree char *str = NULL;
> > const char *end;
> > - char *sysfspath = NULL;
> > + 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;
> > + }
> > + return ret;
> > +}
> > +#endif
> > +
> > +static int hdev_get_max_segments(int fd, struct stat *st)
> > +{
> > +#ifdef CONFIG_LINUX
> > int ret;
> > - int sysfd = -1;
> > - long max_segments;
> >
> > if (S_ISCHR(st->st_mode)) {
> > if (ioctl(fd, SG_GET_SG_TABLESIZE, &ret) == 0) {
> > @@ -1218,44 +1292,27 @@ static int hdev_get_max_segments(int fd, struct stat *st)
> > }
> > return -ENOTSUP;
> > }
> > -
> > - if (!S_ISBLK(st->st_mode)) {
> > - return -ENOTSUP;
> > - }
> > -
> > - 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;
> > - }
> > - ret = RETRY_ON_EINTR(read(sysfd, buf, sizeof(buf) - 1));
> > - if (ret < 0) {
> > - ret = -errno;
> > - goto out;
> > - } else if (ret == 0) {
> > - ret = -EIO;
> > - goto out;
> > - }
> > - 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;
> > - }
> > -
> > -out:
> > - if (sysfd != -1) {
> > - close(sysfd);
> > - }
> > - g_free(sysfspath);
> > - return ret;
> > + return get_sysfs_long_val(st, "max_segments");
> > #else
> > return -ENOTSUP;
> > #endif
> > }
> >
> > +static void raw_refresh_zoned_limits(BlockDriverState *bs, struct stat *st,
> > + Error **errp)
> > +{
> > + BlockZoneModel zoned;
> > + int ret;
> > +
> > + bs->bl.zoned = BLK_Z_NONE;
> > +
> > + ret = get_sysfs_zoned_model(st, &zoned);
> > + if (ret < 0 || zoned == BLK_Z_NONE) {
> > + return;
> > + }
> > + bs->bl.zoned = zoned;
> > +}
> > +
> > static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
> > {
> > BDRVRawState *s = bs->opaque;
> > @@ -1297,6 +1354,8 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
> > bs->bl.max_hw_iov = ret;
> > }
> > }
> > +
> > + raw_refresh_zoned_limits(bs, &st, errp);
> > }
> >
> > static int check_for_dasd(int fd)
>
next prev parent reply other threads:[~2023-06-02 18:19 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-15 16:04 [PULL v2 00/16] Block patches Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 01/16] block/block-common: add zoned device structs Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 02/16] block/file-posix: introduce helper functions for sysfs attributes Stefan Hajnoczi
[not found] ` <8b0ced3c-2fb5-2479-fe78-f4956ac037a6@linux.ibm.com>
2023-06-02 18:18 ` Sam Li [this message]
2023-06-02 18:41 ` Matthew Rosato
2023-06-02 18:45 ` Sam Li
2023-05-15 16:04 ` [PULL v2 03/16] block/block-backend: add block layer APIs resembling Linux ZonedBlockDevice ioctls Stefan Hajnoczi
2024-05-03 12:33 ` Peter Maydell
2024-05-07 15:09 ` Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 04/16] block/raw-format: add zone operations to pass through requests Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 05/16] block: add zoned BlockDriver check to block layer Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 06/16] iotests: test new zone operations Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 07/16] block: add some trace events for new block layer APIs Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 08/16] docs/zoned-storage: add zoned device documentation Stefan Hajnoczi
2023-05-15 16:04 ` [PULL v2 09/16] file-posix: add tracking of the zone write pointers Stefan Hajnoczi
2023-05-15 16:05 ` [PULL v2 10/16] block: introduce zone append write for zoned devices Stefan Hajnoczi
2023-06-02 16:51 ` Peter Maydell
2023-06-02 17:23 ` Sam Li
2023-06-02 17:30 ` Peter Maydell
2023-06-02 17:35 ` Sam Li
2023-06-02 17:52 ` Peter Maydell
2023-06-02 18:03 ` Sam Li
2023-05-15 16:05 ` [PULL v2 11/16] qemu-iotests: test zone append operation Stefan Hajnoczi
2023-05-15 16:05 ` [PULL v2 12/16] block: add some trace events for zone append Stefan Hajnoczi
2023-05-15 16:05 ` [PULL v2 13/16] virtio-blk: add zoned storage emulation for zoned devices Stefan Hajnoczi
2023-05-15 16:05 ` [PULL v2 14/16] block: add accounting for zone append operation Stefan Hajnoczi
2023-05-15 16:05 ` [PULL v2 15/16] virtio-blk: add some trace events for zoned emulation Stefan Hajnoczi
2023-05-15 16:05 ` [PULL v2 16/16] docs/zoned-storage:add zoned emulation use case Stefan Hajnoczi
2023-05-15 23:37 ` [PULL v2 00/16] Block patches Richard Henderson
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