Re: [PATCH] splice: fix wrong __splice_from_pipe() usage
On Mon, Jul 16 2007, OGAWA Hirofumi wrote:
> Jens Axboe <[EMAIL PROTECTED]> writes:
>
> >> nfsd_vfs_read() path.
> >>
> >> nfsd_vfs_read()
> >> splice_direct_to_actor()
> >> while(len) {
> >> do_splice_to() [update sd->pos]
> >> -> generic_file_splice_read() [read from sd->pos]
> >> nfsd_direct_splice_actor()
> >> -> __splice_from_pipe()[update sd->pos]
> >> }
> >>
> >> do_splice_to() updates sd->pos for read, and pass updated sd to
> >> __splice_from_pipe(), and __splice_from_pipe() updates sd->pos for
> >> write. So, next do_splice_to() read from wrong position.
> >
> > Ah, I see. Copying the structure over would work, but it seems like a
> > big work-around for something that is essentially bad behaviour in the
> > splice core for direct splicing.
> >
> > Can you check if this works for you?
>
> Simple test was done. The patch works for me.
Great, thanks a lot for retesting. I'll get the patch upstream asap.
--
Jens Axboe
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Re: [PATCH] splice: fix wrong __splice_from_pipe() usage
Jens Axboe <[EMAIL PROTECTED]> writes:
>> nfsd_vfs_read() path.
>>
>> nfsd_vfs_read()
>> splice_direct_to_actor()
>> while(len) {
>> do_splice_to() [update sd->pos]
>> -> generic_file_splice_read() [read from sd->pos]
>> nfsd_direct_splice_actor()
>> -> __splice_from_pipe()[update sd->pos]
>> }
>>
>> do_splice_to() updates sd->pos for read, and pass updated sd to
>> __splice_from_pipe(), and __splice_from_pipe() updates sd->pos for
>> write. So, next do_splice_to() read from wrong position.
>
> Ah, I see. Copying the structure over would work, but it seems like a
> big work-around for something that is essentially bad behaviour in the
> splice core for direct splicing.
>
> Can you check if this works for you?
Simple test was done. The patch works for me.
Thanks.
--
OGAWA Hirofumi <[EMAIL PROTECTED]>
-
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Re: [PATCH] splice: fix wrong __splice_from_pipe() usage
On Mon, Jul 16 2007, OGAWA Hirofumi wrote:
> Jens Axboe <[EMAIL PROTECTED]> writes:
>
> > On Mon, Jul 16 2007, OGAWA Hirofumi wrote:
> >> Hi,
> >>
> >> I've noticed the nfsd read corruption by recent change. And this patch
> >> fixes the problem for me, is this right fix?
> >> --
> >> OGAWA Hirofumi <[EMAIL PROTECTED]>
> >>
> >>
> >> __splice_from_pipe() is updating the sd->pos for the actor, but those
> >> functions are passing the sd of reader side directory. So, splice
> >> updates sd->pos twice.
> >>
> >> This fixes usage of __splice_from_pipe().
> >
> > For sendfile() usage, or the nfsd path that uses splice to send?
>
> nfsd_vfs_read() path.
>
> nfsd_vfs_read()
> splice_direct_to_actor()
> while(len) {
> do_splice_to() [update sd->pos]
> -> generic_file_splice_read() [read from sd->pos]
> nfsd_direct_splice_actor()
> -> __splice_from_pipe()[update sd->pos]
> }
>
> do_splice_to() updates sd->pos for read, and pass updated sd to
> __splice_from_pipe(), and __splice_from_pipe() updates sd->pos for
> write. So, next do_splice_to() read from wrong position.
Ah, I see. Copying the structure over would work, but it seems like a
big work-around for something that is essentially bad behaviour in the
splice core for direct splicing.
Can you check if this works for you?
diff --git a/fs/splice.c b/fs/splice.c
index 6c98286..5e5071a 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1061,8 +1061,9 @@ ssize_t splice_direct_to_actor(struct file *in, struct
splice_desc *sd,
while (len) {
size_t read_len;
+ loff_t pos = sd->pos;
- ret = do_splice_to(in, &sd->pos, pipe, len, flags);
+ ret = do_splice_to(in, &pos, pipe, len, flags);
if (unlikely(ret <= 0))
goto out_release;
@@ -1080,6 +1081,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct
splice_desc *sd,
bytes += ret;
len -= ret;
+ sd->pos = pos;
if (ret < read_len)
goto out_release;
--
Jens Axboe
-
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Re: [PATCH] splice: fix wrong __splice_from_pipe() usage
Jens Axboe <[EMAIL PROTECTED]> writes:
> On Mon, Jul 16 2007, OGAWA Hirofumi wrote:
>> Hi,
>>
>> I've noticed the nfsd read corruption by recent change. And this patch
>> fixes the problem for me, is this right fix?
>> --
>> OGAWA Hirofumi <[EMAIL PROTECTED]>
>>
>>
>> __splice_from_pipe() is updating the sd->pos for the actor, but those
>> functions are passing the sd of reader side directory. So, splice
>> updates sd->pos twice.
>>
>> This fixes usage of __splice_from_pipe().
>
> For sendfile() usage, or the nfsd path that uses splice to send?
nfsd_vfs_read() path.
nfsd_vfs_read()
splice_direct_to_actor()
while(len) {
do_splice_to() [update sd->pos]
-> generic_file_splice_read() [read from sd->pos]
nfsd_direct_splice_actor()
-> __splice_from_pipe()[update sd->pos]
}
do_splice_to() updates sd->pos for read, and pass updated sd to
__splice_from_pipe(), and __splice_from_pipe() updates sd->pos for
write. So, next do_splice_to() read from wrong position.
--
OGAWA Hirofumi <[EMAIL PROTECTED]>
-
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Re: [PATCH] splice: fix wrong __splice_from_pipe() usage
On Mon, Jul 16 2007, OGAWA Hirofumi wrote: > Hi, > > I've noticed the nfsd read corruption by recent change. And this patch > fixes the problem for me, is this right fix? > -- > OGAWA Hirofumi <[EMAIL PROTECTED]> > > > __splice_from_pipe() is updating the sd->pos for the actor, but those > functions are passing the sd of reader side directory. So, splice > updates sd->pos twice. > > This fixes usage of __splice_from_pipe(). For sendfile() usage, or the nfsd path that uses splice to send? -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] splice: fix wrong __splice_from_pipe() usage
Hi,
I've noticed the nfsd read corruption by recent change. And this patch
fixes the problem for me, is this right fix?
--
OGAWA Hirofumi <[EMAIL PROTECTED]>
__splice_from_pipe() is updating the sd->pos for the actor, but those
functions are passing the sd of reader side directory. So, splice
updates sd->pos twice.
This fixes usage of __splice_from_pipe().
Signed-off-by: OGAWA Hirofumi <[EMAIL PROTECTED]>
---
drivers/block/loop.c |5 +++--
fs/nfsd/vfs.c|5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff -puN fs/nfsd/vfs.c~splice-fix-__splice_from_pipe-usage fs/nfsd/vfs.c
--- linux-2.6/fs/nfsd/vfs.c~splice-fix-__splice_from_pipe-usage 2007-07-16
09:30:10.0 +0900
+++ linux-2.6-hirofumi/fs/nfsd/vfs.c2007-07-16 09:30:10.0 +0900
@@ -842,9 +842,10 @@ nfsd_splice_actor(struct pipe_inode_info
}
static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
- struct splice_desc *sd)
+ struct splice_desc *__sd)
{
- return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
+ struct splice_desc sd = *__sd;
+ return __splice_from_pipe(pipe, &sd, nfsd_splice_actor);
}
static __be32
diff -puN drivers/block/loop.c~splice-fix-__splice_from_pipe-usage
drivers/block/loop.c
--- linux-2.6/drivers/block/loop.c~splice-fix-__splice_from_pipe-usage
2007-07-16 09:30:10.0 +0900
+++ linux-2.6-hirofumi/drivers/block/loop.c 2007-07-16 09:30:10.0
+0900
@@ -437,9 +437,10 @@ lo_splice_actor(struct pipe_inode_info *
}
static int
-lo_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd)
+lo_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *__sd)
{
- return __splice_from_pipe(pipe, sd, lo_splice_actor);
+ struct splice_desc sd = *__sd;
+ return __splice_from_pipe(pipe, &sd, lo_splice_actor);
}
static int
_
-
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