From: Jeremy Allison <[email protected]>
To: Stefan Metzmacher <[email protected]>, Jens Axboe <[email protected]>,
Anoop C S <[email protected]>,
Samba Technical <[email protected]>,
io-uring <[email protected]>
Cc: [email protected]
Subject: Re: Data Corruption bug with Samba's vfs_iouring and Linux 5.6.7/5.7rc3
Date: Wed, 6 May 2020 11:01:36 -0700 [thread overview]
Message-ID: <20200506180136.GF3447@jeremy-acer> (raw)
In-Reply-To: <20200506170344.GA32399@jeremy-acer>
[-- Attachment #1: Type: text/plain, Size: 802 bytes --]
On Wed, May 06, 2020 at 10:03:44AM -0700, Jeremy Allison via samba-technical wrote:
> On Wed, May 06, 2020 at 04:08:03PM +0200, Stefan Metzmacher wrote:
> >
> > smbclient is just smart enough to recover itself from the short read.
> > But the windows client isn't.
>
> Well we pay attention to the amount of data returned
> and only increment the next read request by the amount
> actually returned.
>
> I'm amazed that the Windows client doesn't seem to
> check this !
Confirmed. I just ran a copy test from a Windows10
client copying from Samba with the attached patch
applied (when reading from offset zero, reduce
the amount of data returned by 2 bytes to force
a short read return), and it reliably corrupts files.
Windows isn't looking at the DataLength field
of the SMB2_READ response :-(.
[-- Attachment #2: look --]
[-- Type: text/plain, Size: 1015 bytes --]
diff --git a/source3/modules/vfs_io_uring.c b/source3/modules/vfs_io_uring.c
index 378e48d112f..d21a3485536 100644
--- a/source3/modules/vfs_io_uring.c
+++ b/source3/modules/vfs_io_uring.c
@@ -294,6 +294,7 @@ static void vfs_io_uring_fd_handler(struct tevent_context *ev,
struct vfs_io_uring_pread_state {
struct vfs_io_uring_request ur;
struct iovec iov;
+ off_t offset;
};
static struct tevent_req *vfs_io_uring_pread_send(struct vfs_handle_struct *handle,
@@ -319,6 +320,7 @@ static struct tevent_req *vfs_io_uring_pread_send(struct vfs_handle_struct *hand
state->ur.config = config;
state->ur.req = req;
state->ur.state = state;
+ state->offset = offset;
SMBPROFILE_BYTES_ASYNC_START(syscall_asys_pread, profile_p,
state->ur.profile_bytes, n);
@@ -367,6 +369,11 @@ static ssize_t vfs_io_uring_pread_recv(struct tevent_req *req,
ret = state->ur.cqe.res;
}
+ //JRATEST
+ if (ret > 2 && state->offset == 0) {
+ ret = ret - 2;
+ }
+
tevent_req_received(req);
return ret;
}
next prev parent reply other threads:[~2020-05-06 18:01 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 10:04 Data Corruption bug with Samba's vfs_iouring and Linux 5.6.7/5.7rc3 Stefan Metzmacher
2020-05-05 14:41 ` Jens Axboe
2020-05-05 15:44 ` Jens Axboe
2020-05-05 16:53 ` Jens Axboe
2020-05-05 17:39 ` Jens Axboe
2020-05-05 17:48 ` Jeremy Allison
2020-05-05 17:50 ` Jens Axboe
[not found] ` <[email protected]>
2020-05-06 10:33 ` Stefan Metzmacher
2020-05-06 10:41 ` Stefan Metzmacher
[not found] ` <[email protected]>
2020-05-06 14:08 ` Stefan Metzmacher
2020-05-06 14:43 ` Andreas Schneider
2020-05-06 14:46 ` Andreas Schneider
2020-05-06 15:06 ` Stefan Metzmacher
2020-05-06 17:03 ` Jeremy Allison
2020-05-06 17:13 ` Jeremy Allison
2020-05-06 18:01 ` Jeremy Allison [this message]
2020-05-05 20:19 ` Stefan Metzmacher
2020-05-06 12:55 ` Pavel Begunkov
2020-05-06 15:20 ` Stefan Metzmacher
2020-05-06 15:42 ` Pavel Begunkov
2020-05-07 16:43 ` Jens Axboe
2020-05-07 16:48 ` Jeremy Allison
2020-05-07 16:50 ` Jens Axboe
2020-05-07 18:31 ` Jeremy Allison
2020-05-07 18:35 ` Jens Axboe
2020-05-07 18:55 ` Jeremy Allison
2020-05-07 18:58 ` Jens Axboe
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=20200506180136.GF3447@jeremy-acer \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
/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