From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH 1/2] f2fs: read with READ_SYNC when getting dnode page Date: Wed, 27 Feb 2013 08:38:02 +0900 Message-ID: <1361921882.31428.10.camel@kjgkr> References: <1361857068-31613-1-git-send-email-jaegeuk.kim@samsung.com> Reply-To: jaegeuk.kim@samsung.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-8Hl+AHrJWh8ZaqMEvc+2" Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net To: Namjae Jeon Return-path: In-reply-to: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org --=-8Hl+AHrJWh8ZaqMEvc+2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi, 2013-02-26 (=ED=99=94), 18:35 +0900, Namjae Jeon: > 2013/2/26, Jaegeuk Kim : > > It must be set READ_SYNC not READA. > Hi Jaegeuk. > Could you please elaborate more? > Why we need to change READA to READ_SYNC over here, when the purpose > was to read the node page in READ ahead mode. That point was a reason for me to make this bug before. This is get_node_page_ra, not ra_node_page, which means that ra_node_page does actual readahead for another node pages. In summary, get_node_page_ra tries to: 1. grab or read a target node page for the given nid, 2. then, call ra_node_page to read other adjacent node pages in advance. So, when we try to read a target node page by #1, we should submit bio with READ_SYNC instead of READA. I'll add this to the description. Thanks, >=20 > Thanks. > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/node.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > > index e275218..185454f 100644 > > --- a/fs/f2fs/node.c > > +++ b/fs/f2fs/node.c > > @@ -930,7 +930,7 @@ repeat: > > if (!page) > > return ERR_PTR(-ENOMEM); > > > > - err =3D read_node_page(page, READA); > > + err =3D read_node_page(page, READ_SYNC); > > if (err) { > > f2fs_put_page(page, 1); > > return ERR_PTR(err); > > -- > > 1.8.1.3.566.gaa39828 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > --=20 Jaegeuk Kim Samsung --=-8Hl+AHrJWh8ZaqMEvc+2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAABAgAGBQJRLUdaAAoJEEAUqH6CSFDSYkQP/AveJMvleAchrlahqK/aWm5h d7bafABQUa3YTGpXUxMX4Pum7EOgibQiLxtzTqG55t2/w3WqU2sIK8x9BxeIyoIq JB4q1ufZqwGAfQ0wc2UAapnRKCBu7xh8D4nf5U5ijtnwd2/4qNecGUN9bX0YjjAg iFxMXbN+nJmHoSqjNrbi2Lh4qYKmSKcgcDLxRW3DWDP0T4JqMXKFqmBrgETcX0p9 Phan5C6MFTNCQ1wh0JcFwnlUvhjVG6hmi25wqGi+YzdakyDoRElZnBvDBuKBDtB/ OaRVX8LPqzyUNxxy4JqrTgPZ4l6PsjvaZa1jRq8RoxHTcL+0VrO2oJ50G8i08ror CXHuLYk45wXpAxhssD+g8Mj2prtoDles2qxOV8Ru4LPZ0Y585us8T+SXnOjx8EYG SBN7da6n6mTOJpS2Ktf1vqq4GCcsvxJTLGYxyS66skOhrRIw5P4qEagzDcFmPapw r54sAFaIVKQo4Z+zynPD/JPvOyhRksGH5hy5jbZ9F8YO9TnWDyFN5RLj5Oku3kpD ytLg08JTqt122xo1oXu+ULeQ0SAu/5KMmvqtsdmWJ21GALOWAPBh6mnNmuIOVwG2 QyX1ra1XazFfGtg24zLTDouoAALGfQ7q83XLRagFJiw0Tw9BmXaBae4qdg5nDZof fEjpt3M7wrfcyNkj1oFV =FjU1 -----END PGP SIGNATURE----- --=-8Hl+AHrJWh8ZaqMEvc+2--