From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:60893 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752589AbcEBPpk (ORCPT ); Mon, 2 May 2016 11:45:40 -0400 Message-ID: <1462203935.11211.15.camel@kernel.org> Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io From: Vishal Verma To: Christoph Hellwig , Vishal Verma Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Matthew Wilcox , Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Al Viro , Andrew Morton , linux-kernel@vger.kernel.org, Jeff Moyer Date: Mon, 02 May 2016 09:45:35 -0600 In-Reply-To: <20160502145606.GD20589@infradead.org> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> <20160502145606.GD20589@infradead.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Mon, 2016-05-02 at 07:56 -0700, Christoph Hellwig wrote: > > > > index 79defba..97a1f5f 100644 > > --- a/fs/block_dev.c > > +++ b/fs/block_dev.c > > @@ -167,12 +167,21 @@ blkdev_direct_IO(struct kiocb *iocb, struct > > iov_iter *iter, loff_t offset) > >   struct file *file = iocb->ki_filp; > >   struct inode *inode = bdev_file_inode(file); > >   > > - if (IS_DAX(inode)) > > + if (iocb_is_direct(iocb)) > > + return __blockdev_direct_IO(iocb, inode, > > I_BDEV(inode), iter, > > +     offset, > > blkdev_get_block, NULL, > > +     NULL, > > DIO_SKIP_DIO_COUNT); > > + else if (iocb_is_dax(iocb)) > >   return dax_do_io(iocb, inode, iter, offset, > > blkdev_get_block, > >   NULL, DIO_SKIP_DIO_COUNT); > > - return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), > > iter, offset, > > -     blkdev_get_block, NULL, NULL, > > -     DIO_SKIP_DIO_COUNT); > > + else { > > + /* > > +  * If we're in the direct_IO path, either the > > IOCB_DIRECT or > > +  * IOCB_DAX flags must be set. > > +  */ > > + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); > > + return -ENXIO; > > + } > DAX should not even end up in ->direct_IO. Do you mean to say remove the last 'else' clause entirely? I agree that it should never be hit, which is why it is a WARN.. But I'm happy to remove it. > > > > > --- a/fs/xfs/xfs_file.c > > +++ b/fs/xfs/xfs_file.c > > @@ -300,7 +300,7 @@ xfs_file_read_iter( > >   > >   XFS_STATS_INC(mp, xs_read_calls); > >   > > - if (unlikely(iocb->ki_flags & IOCB_DIRECT)) > > + if (unlikely(iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX))) > >   ioflags |= XFS_IO_ISDIRECT; > please also add a XFS_IO_ISDAX flag to propagate the information > properly and allow tracing to display the actual I/O type. Will do. > > > > > +static inline bool iocb_is_dax(struct kiocb *iocb) > >  { > > + return IS_DAX(file_inode(iocb->ki_filp)) && > > + (iocb->ki_flags & IOCB_DAX); > > +} > > + > > +static inline bool iocb_is_direct(struct kiocb *iocb) > > +{ > > + return iocb->ki_flags & IOCB_DIRECT; > >  } > No need for these helpers - especially as IOCB_DAX should never be > set > if IS_DAX is false. Ok. So check the flags directly where needed? > -- > To unsubscribe from this list: send the line "unsubscribe linux- > block" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io Date: Mon, 02 May 2016 09:45:35 -0600 Message-ID: <1462203935.11211.15.camel@kernel.org> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> <20160502145606.GD20589@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Matthew Wilcox , Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Al Viro , Andrew Morton , linux-kernel@vger.kernel.org, Jeff Moyer To: Christoph Hellwig , Vishal Verma Return-path: In-Reply-To: <20160502145606.GD20589@infradead.org> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Mon, 2016-05-02 at 07:56 -0700, Christoph Hellwig wrote: > >=20 > > index 79defba..97a1f5f 100644 > > --- a/fs/block_dev.c > > +++ b/fs/block_dev.c > > @@ -167,12 +167,21 @@ blkdev_direct_IO(struct kiocb *iocb, struct > > iov_iter *iter, loff_t offset) > > =C2=A0 struct file *file =3D iocb->ki_filp; > > =C2=A0 struct inode *inode =3D bdev_file_inode(file); > > =C2=A0 > > - if (IS_DAX(inode)) > > + if (iocb_is_direct(iocb)) > > + return __blockdev_direct_IO(iocb, inode, > > I_BDEV(inode), iter, > > + =C2=A0=C2=A0=C2=A0=C2=A0offset, > > blkdev_get_block, NULL, > > + =C2=A0=C2=A0=C2=A0=C2=A0NULL, > > DIO_SKIP_DIO_COUNT); > > + else if (iocb_is_dax(iocb)) > > =C2=A0 return dax_do_io(iocb, inode, iter, offset, > > blkdev_get_block, > > =C2=A0 NULL, DIO_SKIP_DIO_COUNT); > > - return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), > > iter, offset, > > - =C2=A0=C2=A0=C2=A0=C2=A0blkdev_get_block, NULL, NULL, > > - =C2=A0=C2=A0=C2=A0=C2=A0DIO_SKIP_DIO_COUNT); > > + else { > > + /* > > + =C2=A0* If we're in the direct_IO path, either the > > IOCB_DIRECT or > > + =C2=A0* IOCB_DAX flags must be set. > > + =C2=A0*/ > > + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); > > + return -ENXIO; > > + } > DAX should not even end up in ->direct_IO. Do you mean to say remove the last 'else' clause entirely? I agree that it should never be hit, which is why it is a WARN.. But I'm happy to remove it. >=20 > >=20 > > --- a/fs/xfs/xfs_file.c > > +++ b/fs/xfs/xfs_file.c > > @@ -300,7 +300,7 @@ xfs_file_read_iter( > > =C2=A0 > > =C2=A0 XFS_STATS_INC(mp, xs_read_calls); > > =C2=A0 > > - if (unlikely(iocb->ki_flags & IOCB_DIRECT)) > > + if (unlikely(iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX))) > > =C2=A0 ioflags |=3D XFS_IO_ISDIRECT; > please also add a XFS_IO_ISDAX flag to propagate the information > properly and allow tracing to display the actual I/O type. Will do. >=20 > >=20 > > +static inline bool iocb_is_dax(struct kiocb *iocb) > > =C2=A0{ > > + return IS_DAX(file_inode(iocb->ki_filp)) && > > + (iocb->ki_flags & IOCB_DAX); > > +} > > + > > +static inline bool iocb_is_direct(struct kiocb *iocb) > > +{ > > + return iocb->ki_flags & IOCB_DIRECT; > > =C2=A0} > No need for these helpers - especially as IOCB_DAX should never be > set > if IS_DAX is false. Ok. So check the flags directly where needed? > -- > To unsubscribe from this list: send the line "unsubscribe linux- > block" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at=C2=A0=C2=A0http://vger.kernel.org/majordomo-info= .html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 69D817CCD for ; Mon, 2 May 2016 10:45:42 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay2.corp.sgi.com (Postfix) with ESMTP id 3B1DA304062 for ; Mon, 2 May 2016 08:45:42 -0700 (PDT) Received: from mail.kernel.org ([198.145.29.136]) by cuda.sgi.com with ESMTP id N1F6epShqG92CaYv (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Mon, 02 May 2016 08:45:40 -0700 (PDT) Message-ID: <1462203935.11211.15.camel@kernel.org> Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io From: Vishal Verma Date: Mon, 02 May 2016 09:45:35 -0600 In-Reply-To: <20160502145606.GD20589@infradead.org> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> <20160502145606.GD20589@infradead.org> Mime-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christoph Hellwig , Vishal Verma Cc: Jens Axboe , Jan Kara , Andrew Morton , Matthew Wilcox , linux-nvdimm@ml01.01.org, linux-kernel@vger.kernel.org, xfs@oss.sgi.com, linux-block@vger.kernel.org, linux-mm@kvack.org, Jeff Moyer , Al Viro , linux-fsdevel@vger.kernel.org, Ross Zwisler , linux-ext4@vger.kernel.org, Dan Williams T24gTW9uLCAyMDE2LTA1LTAyIGF0IDA3OjU2IC0wNzAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90 ZToKPiA+IAo+ID4gaW5kZXggNzlkZWZiYS4uOTdhMWY1ZiAxMDA2NDQKPiA+IC0tLSBhL2ZzL2Js b2NrX2Rldi5jCj4gPiArKysgYi9mcy9ibG9ja19kZXYuYwo+ID4gQEAgLTE2NywxMiArMTY3LDIx IEBAIGJsa2Rldl9kaXJlY3RfSU8oc3RydWN0IGtpb2NiICppb2NiLCBzdHJ1Y3QKPiA+IGlvdl9p dGVyICppdGVyLCBsb2ZmX3Qgb2Zmc2V0KQo+ID4gwqAJc3RydWN0IGZpbGUgKmZpbGUgPSBpb2Ni LT5raV9maWxwOwo+ID4gwqAJc3RydWN0IGlub2RlICppbm9kZSA9IGJkZXZfZmlsZV9pbm9kZShm aWxlKTsKPiA+IMKgCj4gPiAtCWlmIChJU19EQVgoaW5vZGUpKQo+ID4gKwlpZiAoaW9jYl9pc19k aXJlY3QoaW9jYikpCj4gPiArCQlyZXR1cm4gX19ibG9ja2Rldl9kaXJlY3RfSU8oaW9jYiwgaW5v ZGUsCj4gPiBJX0JERVYoaW5vZGUpLCBpdGVyLAo+ID4gKwkJCQkJwqDCoMKgwqBvZmZzZXQsCj4g PiBibGtkZXZfZ2V0X2Jsb2NrLCBOVUxMLAo+ID4gKwkJCQkJwqDCoMKgwqBOVUxMLAo+ID4gRElP X1NLSVBfRElPX0NPVU5UKTsKPiA+ICsJZWxzZSBpZiAoaW9jYl9pc19kYXgoaW9jYikpCj4gPiDC oAkJcmV0dXJuIGRheF9kb19pbyhpb2NiLCBpbm9kZSwgaXRlciwgb2Zmc2V0LAo+ID4gYmxrZGV2 X2dldF9ibG9jaywKPiA+IMKgCQkJCU5VTEwsIERJT19TS0lQX0RJT19DT1VOVCk7Cj4gPiAtCXJl dHVybiBfX2Jsb2NrZGV2X2RpcmVjdF9JTyhpb2NiLCBpbm9kZSwgSV9CREVWKGlub2RlKSwKPiA+ IGl0ZXIsIG9mZnNldCwKPiA+IC0JCQkJwqDCoMKgwqBibGtkZXZfZ2V0X2Jsb2NrLCBOVUxMLCBO VUxMLAo+ID4gLQkJCQnCoMKgwqDCoERJT19TS0lQX0RJT19DT1VOVCk7Cj4gPiArCWVsc2Ugewo+ ID4gKwkJLyoKPiA+ICsJCcKgKiBJZiB3ZSdyZSBpbiB0aGUgZGlyZWN0X0lPIHBhdGgsIGVpdGhl ciB0aGUKPiA+IElPQ0JfRElSRUNUIG9yCj4gPiArCQnCoCogSU9DQl9EQVggZmxhZ3MgbXVzdCBi ZSBzZXQuCj4gPiArCQnCoCovCj4gPiArCQlXQVJOX09OQ0UoMSwgIktlcm5lbCBCdWcgd2l0aCBp b2NiIGZsYWdzXG4iKTsKPiA+ICsJCXJldHVybiAtRU5YSU87Cj4gPiArCX0KPiBEQVggc2hvdWxk IG5vdCBldmVuIGVuZCB1cCBpbiAtPmRpcmVjdF9JTy4KCkRvIHlvdSBtZWFuIHRvIHNheSByZW1v dmUgdGhlIGxhc3QgJ2Vsc2UnIGNsYXVzZSBlbnRpcmVseT8KSSBhZ3JlZSB0aGF0IGl0IHNob3Vs ZCBuZXZlciBiZSBoaXQsIHdoaWNoIGlzIHdoeSBpdCBpcyBhIFdBUk4uLgpCdXQgSSdtIGhhcHB5 IHRvIHJlbW92ZSBpdC4KCj4gCj4gPiAKPiA+IC0tLSBhL2ZzL3hmcy94ZnNfZmlsZS5jCj4gPiAr KysgYi9mcy94ZnMveGZzX2ZpbGUuYwo+ID4gQEAgLTMwMCw3ICszMDAsNyBAQCB4ZnNfZmlsZV9y ZWFkX2l0ZXIoCj4gPiDCoAo+ID4gwqAJWEZTX1NUQVRTX0lOQyhtcCwgeHNfcmVhZF9jYWxscyk7 Cj4gPiDCoAo+ID4gLQlpZiAodW5saWtlbHkoaW9jYi0+a2lfZmxhZ3MgJiBJT0NCX0RJUkVDVCkp Cj4gPiArCWlmICh1bmxpa2VseShpb2NiLT5raV9mbGFncyAmIChJT0NCX0RJUkVDVCB8IElPQ0Jf REFYKSkpCj4gPiDCoAkJaW9mbGFncyB8PSBYRlNfSU9fSVNESVJFQ1Q7Cj4gcGxlYXNlIGFsc28g YWRkIGEgWEZTX0lPX0lTREFYIGZsYWcgdG8gcHJvcGFnYXRlIHRoZSBpbmZvcm1hdGlvbgo+IHBy b3Blcmx5IGFuZCBhbGxvdyB0cmFjaW5nIHRvIGRpc3BsYXkgdGhlIGFjdHVhbCBJL08gdHlwZS4K CldpbGwgZG8uCgo+IAo+ID4gCj4gPiArc3RhdGljIGlubGluZSBib29sIGlvY2JfaXNfZGF4KHN0 cnVjdCBraW9jYiAqaW9jYikKPiA+IMKgewo+ID4gKwlyZXR1cm4gSVNfREFYKGZpbGVfaW5vZGUo aW9jYi0+a2lfZmlscCkpICYmCj4gPiArCQkoaW9jYi0+a2lfZmxhZ3MgJiBJT0NCX0RBWCk7Cj4g PiArfQo+ID4gKwo+ID4gK3N0YXRpYyBpbmxpbmUgYm9vbCBpb2NiX2lzX2RpcmVjdChzdHJ1Y3Qg a2lvY2IgKmlvY2IpCj4gPiArewo+ID4gKwlyZXR1cm4gaW9jYi0+a2lfZmxhZ3MgJiBJT0NCX0RJ UkVDVDsKPiA+IMKgfQo+IE5vIG5lZWQgZm9yIHRoZXNlIGhlbHBlcnMgLSBlc3BlY2lhbGx5IGFz IElPQ0JfREFYIHNob3VsZCBuZXZlciBiZQo+IHNldAo+IGlmIElTX0RBWCBpcyBmYWxzZS4KCk9r LiBTbyBjaGVjayB0aGUgZmxhZ3MgZGlyZWN0bHkgd2hlcmUgbmVlZGVkPwoKPiAtLQo+IFRvIHVu c3Vic2NyaWJlIGZyb20gdGhpcyBsaXN0OiBzZW5kIHRoZSBsaW5lICJ1bnN1YnNjcmliZSBsaW51 eC0KPiBibG9jayIgaW4KPiB0aGUgYm9keSBvZiBhIG1lc3NhZ2UgdG8gbWFqb3Jkb21vQHZnZXIu a2VybmVsLm9yZwo+IE1vcmUgbWFqb3Jkb21vIGluZm8gYXTCoMKgaHR0cDovL3ZnZXIua2VybmVs Lm9yZy9tYWpvcmRvbW8taW5mby5odG1sCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fXwp4ZnMgbWFpbGluZyBsaXN0Cnhmc0Bvc3Muc2dpLmNvbQpodHRwOi8v b3NzLnNnaS5jb20vbWFpbG1hbi9saXN0aW5mby94ZnMK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 2C27E6B0253 for ; 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[198.145.29.136]) by mx.google.com with ESMTPS id fk7si23054559pab.97.2016.05.02.08.45.39 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 May 2016 08:45:39 -0700 (PDT) Message-ID: <1462203935.11211.15.camel@kernel.org> Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io From: Vishal Verma Date: Mon, 02 May 2016 09:45:35 -0600 In-Reply-To: <20160502145606.GD20589@infradead.org> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> <20160502145606.GD20589@infradead.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig , Vishal Verma Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Matthew Wilcox , Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Al Viro , Andrew Morton , linux-kernel@vger.kernel.org, Jeff Moyer On Mon, 2016-05-02 at 07:56 -0700, Christoph Hellwig wrote: > > > > index 79defba..97a1f5f 100644 > > --- a/fs/block_dev.c > > +++ b/fs/block_dev.c > > @@ -167,12 +167,21 @@ blkdev_direct_IO(struct kiocb *iocb, struct > > iov_iter *iter, loff_t offset) > > A struct file *file = iocb->ki_filp; > > A struct inode *inode = bdev_file_inode(file); > > A > > - if (IS_DAX(inode)) > > + if (iocb_is_direct(iocb)) > > + return __blockdev_direct_IO(iocb, inode, > > I_BDEV(inode), iter, > > + A A A A offset, > > blkdev_get_block, NULL, > > + A A A A NULL, > > DIO_SKIP_DIO_COUNT); > > + else if (iocb_is_dax(iocb)) > > A return dax_do_io(iocb, inode, iter, offset, > > blkdev_get_block, > > A NULL, DIO_SKIP_DIO_COUNT); > > - return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), > > iter, offset, > > - A A A A blkdev_get_block, NULL, NULL, > > - A A A A DIO_SKIP_DIO_COUNT); > > + else { > > + /* > > + A * If we're in the direct_IO path, either the > > IOCB_DIRECT or > > + A * IOCB_DAX flags must be set. > > + A */ > > + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); > > + return -ENXIO; > > + } > DAX should not even end up in ->direct_IO. Do you mean to say remove the last 'else' clause entirely? I agree that it should never be hit, which is why it is a WARN.. But I'm happy to remove it. > > > > > --- a/fs/xfs/xfs_file.c > > +++ b/fs/xfs/xfs_file.c > > @@ -300,7 +300,7 @@ xfs_file_read_iter( > > A > > A XFS_STATS_INC(mp, xs_read_calls); > > A > > - if (unlikely(iocb->ki_flags & IOCB_DIRECT)) > > + if (unlikely(iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX))) > > A ioflags |= XFS_IO_ISDIRECT; > please also add a XFS_IO_ISDAX flag to propagate the information > properly and allow tracing to display the actual I/O type. Will do. > > > > > +static inline bool iocb_is_dax(struct kiocb *iocb) > > A { > > + return IS_DAX(file_inode(iocb->ki_filp)) && > > + (iocb->ki_flags & IOCB_DAX); > > +} > > + > > +static inline bool iocb_is_direct(struct kiocb *iocb) > > +{ > > + return iocb->ki_flags & IOCB_DIRECT; > > A } > No need for these helpers - especially as IOCB_DAX should never be > set > if IS_DAX is false. Ok. So check the flags directly where needed? > -- > To unsubscribe from this list: send the line "unsubscribe linux- > block" in > the body of a message to majordomo@vger.kernel.org > More majordomo info atA A http://vger.kernel.org/majordomo-info.html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754226AbcEBPps (ORCPT ); Mon, 2 May 2016 11:45:48 -0400 Received: from mail.kernel.org ([198.145.29.136]:60893 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752589AbcEBPpk (ORCPT ); Mon, 2 May 2016 11:45:40 -0400 Message-ID: <1462203935.11211.15.camel@kernel.org> Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io From: Vishal Verma To: Christoph Hellwig , Vishal Verma Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Matthew Wilcox , Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Al Viro , Andrew Morton , linux-kernel@vger.kernel.org, Jeff Moyer Date: Mon, 02 May 2016 09:45:35 -0600 In-Reply-To: <20160502145606.GD20589@infradead.org> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> <20160502145606.GD20589@infradead.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2 (3.18.5.2-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2016-05-02 at 07:56 -0700, Christoph Hellwig wrote: > > > > index 79defba..97a1f5f 100644 > > --- a/fs/block_dev.c > > +++ b/fs/block_dev.c > > @@ -167,12 +167,21 @@ blkdev_direct_IO(struct kiocb *iocb, struct > > iov_iter *iter, loff_t offset) > >   struct file *file = iocb->ki_filp; > >   struct inode *inode = bdev_file_inode(file); > >   > > - if (IS_DAX(inode)) > > + if (iocb_is_direct(iocb)) > > + return __blockdev_direct_IO(iocb, inode, > > I_BDEV(inode), iter, > > +     offset, > > blkdev_get_block, NULL, > > +     NULL, > > DIO_SKIP_DIO_COUNT); > > + else if (iocb_is_dax(iocb)) > >   return dax_do_io(iocb, inode, iter, offset, > > blkdev_get_block, > >   NULL, DIO_SKIP_DIO_COUNT); > > - return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), > > iter, offset, > > -     blkdev_get_block, NULL, NULL, > > -     DIO_SKIP_DIO_COUNT); > > + else { > > + /* > > +  * If we're in the direct_IO path, either the > > IOCB_DIRECT or > > +  * IOCB_DAX flags must be set. > > +  */ > > + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); > > + return -ENXIO; > > + } > DAX should not even end up in ->direct_IO. Do you mean to say remove the last 'else' clause entirely? I agree that it should never be hit, which is why it is a WARN.. But I'm happy to remove it. > > > > > --- a/fs/xfs/xfs_file.c > > +++ b/fs/xfs/xfs_file.c > > @@ -300,7 +300,7 @@ xfs_file_read_iter( > >   > >   XFS_STATS_INC(mp, xs_read_calls); > >   > > - if (unlikely(iocb->ki_flags & IOCB_DIRECT)) > > + if (unlikely(iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX))) > >   ioflags |= XFS_IO_ISDIRECT; > please also add a XFS_IO_ISDAX flag to propagate the information > properly and allow tracing to display the actual I/O type. Will do. > > > > > +static inline bool iocb_is_dax(struct kiocb *iocb) > >  { > > + return IS_DAX(file_inode(iocb->ki_filp)) && > > + (iocb->ki_flags & IOCB_DAX); > > +} > > + > > +static inline bool iocb_is_direct(struct kiocb *iocb) > > +{ > > + return iocb->ki_flags & IOCB_DIRECT; > >  } > No need for these helpers - especially as IOCB_DAX should never be > set > if IS_DAX is false. Ok. So check the flags directly where needed? > -- > To unsubscribe from this list: send the line "unsubscribe linux- > block" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html