From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: kwolf@redhat.com, qemu-block@nongnu.org
Subject: [PATCH v3 1/7] file-posix: fix max_iov for /dev/sg devices
Date: Thu, 3 Jun 2021 15:37:16 +0200 [thread overview]
Message-ID: <20210603133722.218465-2-pbonzini@redhat.com> (raw)
In-Reply-To: <20210603133722.218465-1-pbonzini@redhat.com>
Even though it was only called for devices that have bs->sg set (which
must be character devices),
sg_get_max_segments looked at /sys/dev/block which only works for
block devices.
On Linux the sg driver has its own way to provide the maximum number of
iovecs in a scatter/gather list.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
block/file-posix.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/block/file-posix.c b/block/file-posix.c
index f37dfc10b3..58db526cc2 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1180,6 +1180,17 @@ static int sg_get_max_segments(int fd)
goto out;
}
+ if (S_ISCHR(st->st_mode)) {
+ if (ioctl(fd, SG_GET_SG_TABLESIZE, &ret) == 0) {
+ return ret;
+ }
+ return -EIO;
+ }
+
+ 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);
--
2.31.1
next prev parent reply other threads:[~2021-06-03 13:38 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 13:37 [PATCH v3 0/7] block: file-posix queue Paolo Bonzini
2021-06-03 13:37 ` Paolo Bonzini [this message]
2021-06-07 5:39 ` [PATCH v3 1/7] file-posix: fix max_iov for /dev/sg devices Vladimir Sementsov-Ogievskiy
2021-06-07 6:16 ` Vladimir Sementsov-Ogievskiy
2021-06-07 7:23 ` Vladimir Sementsov-Ogievskiy
2021-06-15 15:58 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 2/7] scsi-generic: pass max_segments via max_iov field in BlockLimits Paolo Bonzini
2021-06-15 16:06 ` Max Reitz
2021-06-15 16:20 ` Max Reitz
2021-06-15 17:41 ` Paolo Bonzini
2021-06-03 13:37 ` [PATCH v3 3/7] block: add max_hw_transfer to BlockLimits Paolo Bonzini
2021-06-03 17:33 ` Eric Blake
2021-06-04 7:21 ` Paolo Bonzini
2021-06-15 16:18 ` Max Reitz
2021-06-16 13:18 ` Paolo Bonzini
2021-06-16 13:46 ` Max Reitz
2021-06-17 9:59 ` Paolo Bonzini
2021-06-03 13:37 ` [PATCH v3 4/7] file-posix: try BLKSECTGET on block devices too, do not round to power of 2 Paolo Bonzini
2021-06-15 16:32 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 5/7] block: feature detection for host block support Paolo Bonzini
2021-06-15 16:40 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 6/7] block: check for sys/disk.h Paolo Bonzini
2021-06-15 16:42 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 7/7] block: detect DKIOCGETBLOCKCOUNT/SIZE before use Paolo Bonzini
2021-06-15 16:50 ` Max Reitz
2021-06-15 16:57 ` Daniel P. Berrangé
2021-06-07 13:52 ` [PATCH v3 0/7] block: file-posix queue Maxim Levitsky
2021-06-10 13:40 ` Paolo Bonzini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210603133722.218465-2-pbonzini@redhat.com \
--to=pbonzini@redhat.com \
--cc=kwolf@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).