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[23.128.96.18]) by mx.google.com with ESMTP id w5si2020736ejb.404.2020.07.15.16.53.12; Wed, 15 Jul 2020 16:53:35 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727120AbgGOXvD (ORCPT + 99 others); Wed, 15 Jul 2020 19:51:03 -0400 Received: from mx2.suse.de ([195.135.220.15]:53352 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726479AbgGOXvD (ORCPT ); Wed, 15 Jul 2020 19:51:03 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id F2C66AC37; Wed, 15 Jul 2020 23:50:59 +0000 (UTC) From: NeilBrown To: Christoph Hellwig , linux-kernel@vger.kernel.org Date: Thu, 16 Jul 2020 09:50:49 +1000 Cc: "H. Peter Anvin" , Song Liu , Al Viro , Linus Torvalds , linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 09/23] md: rewrite md_setup_drive to avoid ioctls In-Reply-To: <20200714190427.4332-10-hch@lst.de> References: <20200714190427.4332-1-hch@lst.de> <20200714190427.4332-10-hch@lst.de> Message-ID: <87365sxrqe.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, Jul 14 2020, Christoph Hellwig wrote: > md_setup_drive knows it works with md devices, so it is rather pointless > to open a file descriptor and issue ioctls. Just call directly into the > relevant low-level md routines after getting a handle to the device using > blkdev_get_by_dev instead. > > Signed-off-by: Christoph Hellwig > Acked-by: Song Liu > --- > drivers/md/md-autodetect.c | 127 ++++++++++++++++--------------------- > drivers/md/md.c | 20 +++--- > drivers/md/md.h | 6 ++ > 3 files changed, 71 insertions(+), 82 deletions(-) > > diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c > index a43a8f1580584c..5b24b5616d3acc 100644 > --- a/drivers/md/md-autodetect.c > +++ b/drivers/md/md-autodetect.c > @@ -2,7 +2,6 @@ > #include > #include > #include > -#include > #include > #include > #include > @@ -120,37 +119,29 @@ static int __init md_setup(char *str) > return 1; > } >=20=20 > -static inline int create_dev(char *name, dev_t dev) > -{ > - ksys_unlink(name); > - return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev)); > -} > - > static void __init md_setup_drive(struct md_setup_args *args) > { > - int minor, i, partitioned; > - dev_t dev; > - dev_t devices[MD_SB_DISKS+1]; > - int fd; > - int err =3D 0; > - char *devname; > - mdu_disk_info_t dinfo; > + char *devname =3D args->device_names; > + dev_t devices[MD_SB_DISKS + 1], mdev; > + struct mdu_array_info_s ainfo =3D { }; > + struct block_device *bdev; > + struct mddev *mddev; > + int err =3D 0, i; > char name[16]; >=20=20 > - minor =3D args->minor; > - partitioned =3D args->partitioned; > - devname =3D args->device_names; > + if (args->partitioned) { > + mdev =3D MKDEV(mdp_major, args->minor << MdpMinorShift); > + sprintf(name, "md_d%d", args->minor); > + } else { > + mdev =3D MKDEV(MD_MAJOR, args->minor); > + sprintf(name, "md%d", args->minor); > + } >=20=20 > - sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor); > - if (partitioned) > - dev =3D MKDEV(mdp_major, minor << MdpMinorShift); > - else > - dev =3D MKDEV(MD_MAJOR, minor); > - create_dev(name, dev); > for (i =3D 0; i < MD_SB_DISKS && devname !=3D NULL; i++) { > struct kstat stat; > char *p; > char comp_name[64]; > + dev_t dev; >=20=20 > p =3D strchr(devname, ','); > if (p) > @@ -163,7 +154,7 @@ static void __init md_setup_drive(struct md_setup_arg= s *args) > if (vfs_stat(comp_name, &stat) =3D=3D 0 && S_ISBLK(stat.mode)) > dev =3D new_decode_dev(stat.rdev); > if (!dev) { > - printk(KERN_WARNING "md: Unknown device name: %s\n", devname); > + pr_warn("md: Unknown device name: %s\n", devname); > break; > } >=20=20 > @@ -175,68 +166,64 @@ static void __init md_setup_drive(struct md_setup_a= rgs *args) > if (!i) > return; >=20=20 > - printk(KERN_INFO "md: Loading md%s%d: %s\n", > - partitioned ? "_d" : "", minor, > - args->device_names); > + pr_info("md: Loading %s: %s\n", name, args->device_names); >=20=20 > - fd =3D ksys_open(name, 0, 0); > - if (fd < 0) { > - printk(KERN_ERR "md: open failed - cannot start " > - "array %s\n", name); > + bdev =3D blkdev_get_by_dev(mdev, FMODE_READ, NULL); > + if (IS_ERR(bdev)) { > + pr_err("md: open failed - cannot start array %s\n", name); > return; > } > - if (ksys_ioctl(fd, SET_ARRAY_INFO, 0) =3D=3D -EBUSY) { > - printk(KERN_WARNING > - "md: Ignoring md=3D%d, already autodetected. (Use raid=3Dnoauto= detect)\n", > - minor); > - ksys_close(fd); > - return; I'd be more comfortable if you added something like if (WARN(bdev->bd_disk->fops !=3D md_fops, "Opening block device %x resulted in non-md device\")) return; here. However even without that Reviewed-by: NeilBrown Thanks, NeilBrown > + mddev =3D bdev->bd_disk->private_data; > + > + err =3D mddev_lock(mddev); > + if (err) { > + pr_err("md: failed to lock array %s\n", name); > + goto out_blkdev_put; > + } > + > + if (!list_empty(&mddev->disks) || mddev->raid_disks) { > + pr_warn("md: Ignoring %s, already autodetected. (Use raid=3Dnoautodete= ct)\n", > + name); > + goto out_unlock; > } >=20=20 > if (args->level !=3D LEVEL_NONE) { > /* non-persistent */ > - mdu_array_info_t ainfo; > ainfo.level =3D args->level; > - ainfo.size =3D 0; > - ainfo.nr_disks =3D0; > - ainfo.raid_disks =3D0; > - while (devices[ainfo.raid_disks]) > - ainfo.raid_disks++; > - ainfo.md_minor =3Dminor; > + ainfo.md_minor =3D args->minor; > ainfo.not_persistent =3D 1; > - > ainfo.state =3D (1 << MD_SB_CLEAN); > - ainfo.layout =3D 0; > ainfo.chunk_size =3D args->chunk; > - err =3D ksys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo); > - for (i =3D 0; !err && i <=3D MD_SB_DISKS; i++) { > - dev =3D devices[i]; > - if (!dev) > - break; > + while (devices[ainfo.raid_disks]) > + ainfo.raid_disks++; > + } > + > + err =3D md_set_array_info(mddev, &ainfo); > + > + for (i =3D 0; i <=3D MD_SB_DISKS && devices[i]; i++) { > + struct mdu_disk_info_s dinfo =3D { > + .major =3D MAJOR(devices[i]), > + .minor =3D MINOR(devices[i]), > + }; > + > + if (args->level !=3D LEVEL_NONE) { > dinfo.number =3D i; > dinfo.raid_disk =3D i; > - dinfo.state =3D (1< - dinfo.major =3D MAJOR(dev); > - dinfo.minor =3D MINOR(dev); > - err =3D ksys_ioctl(fd, ADD_NEW_DISK, > - (long)&dinfo); > - } > - } else { > - /* persistent */ > - for (i =3D 0; i <=3D MD_SB_DISKS; i++) { > - dev =3D devices[i]; > - if (!dev) > - break; > - dinfo.major =3D MAJOR(dev); > - dinfo.minor =3D MINOR(dev); > - ksys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo); > + dinfo.state =3D > + (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC); > } > + > + md_add_new_disk(mddev, &dinfo); > } > + > if (!err) > - err =3D ksys_ioctl(fd, RUN_ARRAY, 0); > + err =3D do_md_run(mddev); > if (err) > - printk(KERN_WARNING "md: starting md%d failed\n", minor); > - ksys_close(fd); > + pr_warn("md: starting %s failed\n", name); > +out_unlock: > + mddev_unlock(mddev); > +out_blkdev_put: > + blkdev_put(bdev, FMODE_READ); > } >=20=20 > static int __init raid_setup(char *str) > @@ -286,8 +273,6 @@ void __init md_run_setup(void) > { > int ent; >=20=20 > - create_dev("/dev/md0", MKDEV(MD_MAJOR, 0)); > - > if (raid_noautodetect) > printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=3Da= utodetect will force)\n"); > else > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 6e9a48da474848..9960cfeb59a50c 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -4368,7 +4368,6 @@ array_state_show(struct mddev *mddev, char *page) >=20=20 > static int do_md_stop(struct mddev *mddev, int ro, struct block_device *= bdev); > static int md_set_readonly(struct mddev *mddev, struct block_device *bde= v); > -static int do_md_run(struct mddev *mddev); > static int restart_array(struct mddev *mddev); >=20=20 > static ssize_t > @@ -6015,7 +6014,7 @@ int md_run(struct mddev *mddev) > } > EXPORT_SYMBOL_GPL(md_run); >=20=20 > -static int do_md_run(struct mddev *mddev) > +int do_md_run(struct mddev *mddev) > { > int err; >=20=20 > @@ -6651,7 +6650,7 @@ static int get_disk_info(struct mddev *mddev, void = __user * arg) > return 0; > } >=20=20 > -static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info) > +int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info) > { > char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE]; > struct md_rdev *rdev; > @@ -6697,7 +6696,7 @@ static int add_new_disk(struct mddev *mddev, mdu_di= sk_info_t *info) > } >=20=20 > /* > - * add_new_disk can be used once the array is assembled > + * md_add_new_disk can be used once the array is assembled > * to add "hot spares". They must already have a superblock > * written > */ > @@ -6810,7 +6809,7 @@ static int add_new_disk(struct mddev *mddev, mdu_di= sk_info_t *info) > return err; > } >=20=20 > - /* otherwise, add_new_disk is only allowed > + /* otherwise, md_add_new_disk is only allowed > * for major_version=3D=3D0 superblocks > */ > if (mddev->major_version !=3D 0) { > @@ -7055,7 +7054,7 @@ static int set_bitmap_file(struct mddev *mddev, int= fd) > } >=20=20 > /* > - * set_array_info is used two different ways > + * md_set_array_info is used two different ways > * The original usage is when creating a new array. > * In this usage, raid_disks is > 0 and it together with > * level, size, not_persistent,layout,chunksize determine the > @@ -7067,9 +7066,8 @@ static int set_bitmap_file(struct mddev *mddev, int= fd) > * The minor and patch _version numbers are also kept incase the > * super_block handler wishes to interpret them. > */ > -static int set_array_info(struct mddev *mddev, mdu_array_info_t *info) > +int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info) > { > - > if (info->raid_disks =3D=3D 0) { > /* just setting version number for superblock loading */ > if (info->major_version < 0 || > @@ -7560,7 +7558,7 @@ static int md_ioctl(struct block_device *bdev, fmod= e_t mode, > err =3D -EBUSY; > goto unlock; > } > - err =3D set_array_info(mddev, &info); > + err =3D md_set_array_info(mddev, &info); > if (err) { > pr_warn("md: couldn't set array info. %d\n", err); > goto unlock; > @@ -7614,7 +7612,7 @@ static int md_ioctl(struct block_device *bdev, fmod= e_t mode, > /* Need to clear read-only for this */ > break; > else > - err =3D add_new_disk(mddev, &info); > + err =3D md_add_new_disk(mddev, &info); > goto unlock; > } > break; > @@ -7682,7 +7680,7 @@ static int md_ioctl(struct block_device *bdev, fmod= e_t mode, > if (copy_from_user(&info, argp, sizeof(info))) > err =3D -EFAULT; > else > - err =3D add_new_disk(mddev, &info); > + err =3D md_add_new_disk(mddev, &info); > goto unlock; > } >=20=20 > diff --git a/drivers/md/md.h b/drivers/md/md.h > index 6f8fff77ce10a5..7ee81aa2eac862 100644 > --- a/drivers/md/md.h > +++ b/drivers/md/md.h > @@ -801,7 +801,13 @@ static inline void mddev_check_write_zeroes(struct m= ddev *mddev, struct bio *bio > mddev->queue->limits.max_write_zeroes_sectors =3D 0; > } >=20=20 > +struct mdu_array_info_s; > +struct mdu_disk_info_s; > + > extern int mdp_major; > void md_autostart_arrays(int part); > +int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info= ); > +int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info); > +int do_md_run(struct mddev *mddev); >=20=20 > #endif /* _MD_MD_H */ > --=20 > 2.27.0 --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAl8PllkACgkQOeye3VZi gblpCg//Y3mGVscw9giutzGjsI/GWiOtxrJda5+l/LnqsnN32w+YCMW99gk1UEOF E0xl0nOmj7H333nr6slpP6aMspvSt1unkv7Pd1XsnGM0nQGpuvIBXnErK8vLJoYL wITl9XIgG51xUI52LWe+F/ksrQz0jqUljYfqEoAtYZSaQpLn+ukyM098d8qXV9Sa yFtinpRlLaDQqz7Gzh029IGnHjtF0HFJhbzRPpJeOFs3tC7QiegcZCM1GGmX1qHj EpdLliWiQxP6m33JIZf9EIgE56SWNwi62O0FJiOqjGpF5HRb1LLlFGzQA+loLFdG fdAfyQ82D1x8CXdrmchyVxb4BYqB3jHiXiuwJqc6Ot7LwI/o8zkH5dRuxcWtTKq0 JGU/1FLdb/yXNX7DbrND/BP0j//1Ht54cCzAmC2FWgxPBveQ9Rlqn7UQF5NTQpWT RwdeCYOsncAgb3gScEDuZfH1J4DVnub9bSYlGZGbrO4ALF+qO4lagFiOpRXlt/OO eeQqkhr3gMViuCntk/gWcID4fotjn8hftLPJPziwCfUx4BAg6AU4JyGjFQlmfavA 3ARNdMUfhPksbT4CxL7ks7gIMEuDmFSOFhpEHbI3nOjjxJGKegUaDS/1Kyj/792Q igbbT8CnJ2z4jQOn23nVbj9sB6LciBnNEpzVJ7FMtQXevygSL8k= =7Xpw -----END PGP SIGNATURE----- --=-=-=--