From owner-freebsd-fs@FreeBSD.ORG Tue Aug 7 18:01:00 2007 Return-Path: Delivered-To: fs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B289516A46E; Tue, 7 Aug 2007 18:01:00 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from relay01.kiev.sovam.com (relay01.kiev.sovam.com [62.64.120.200]) by mx1.freebsd.org (Postfix) with ESMTP id 4C21C13C4B6; Tue, 7 Aug 2007 18:01:00 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from [89.162.146.170] (helo=skuns.kiev.zoral.com.ua) by relay01.kiev.sovam.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1IITMR-0008dw-5t; Tue, 07 Aug 2007 21:00:58 +0300 Received: from deviant.kiev.zoral.com.ua (root@[10.1.1.148]) by skuns.kiev.zoral.com.ua (8.14.1/8.14.1) with ESMTP id l77H30lf095871 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 7 Aug 2007 20:03:00 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.1/8.14.1) with ESMTP id l77H30Y9099979; Tue, 7 Aug 2007 20:03:00 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.1/8.14.1/Submit) id l77H2x4g099978; Tue, 7 Aug 2007 20:02:59 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Tue, 7 Aug 2007 20:02:59 +0300 From: Kostik Belousov To: Bruce Evans Message-ID: <20070807170259.GJ2738@deviant.kiev.zoral.com.ua> References: <20070710233455.O2101@besplex.bde.org> <20070712084115.GA2200@deviant.kiev.zoral.com.ua> <20070712225324.F9515@besplex.bde.org> <20070712142127.GD2200@deviant.kiev.zoral.com.ua> <20070716195556.P12807@besplex.bde.org> <20070721063434.GI2200@deviant.kiev.zoral.com.ua> <20070721233613.Q3366@besplex.bde.org> <20070804075730.GP2738@deviant.kiev.zoral.com.ua> <20070808004001.O926@besplex.bde.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ISA6zNVXmTIvvkD5" Content-Disposition: inline In-Reply-To: <20070808004001.O926@besplex.bde.org> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: ClamAV version 0.91.1, clamav-milter version 0.91.1 on skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-1.4 required=5.0 tests=ALL_TRUSTED autolearn=failed version=3.2.1 X-Spam-Checker-Version: SpamAssassin 3.2.1 (2007-05-02) on skuns.kiev.zoral.com.ua X-Scanner-Signature: 7bc32d9c6161d64a6ed1bdcc9b38fdca X-DrWeb-checked: yes X-SpamTest-Envelope-From: kostikbel@gmail.com X-SpamTest-Group-ID: 00000000 X-SpamTest-Header: Not Detected X-SpamTest-Info: Profiles 1351 [August 7 2007] X-SpamTest-Info: helo_type=3 X-SpamTest-Method: none X-SpamTest-Rate: 0 X-SpamTest-Status: Not detected X-SpamTest-Status-Extended: not_detected X-SpamTest-Version: SMTP-Filter Version 3.0.0 [0255], KAS30/Release Cc: bugs@FreeBSD.org, fs@FreeBSD.org Subject: Re: msdosfs not MPSAFE X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Aug 2007 18:01:00 -0000 --ISA6zNVXmTIvvkD5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 08, 2007 at 12:48:06AM +1000, Bruce Evans wrote: > Here is a cleaned up version for -current for further review. I can't > see how to do it cleanly without all the little functions. It also > fixes a memory leak on module unload, and some style bugs in > msdosfs_vfsops.c. This has been tested lightly runtime. Module unload > has not been tested at all (I don't use modules). Why not allocate nambuf statically ? It seems that using functions for mbnambuf_acquire()/mbnambuf_release() causes unneeded overhead. Macros could be used as well. Anyway, these notes are not objections against patch. >=20 > %%% > Index: direntry.h > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/sys/fs/msdosfs/direntry.h,v > retrieving revision 1.23 > diff -u -2 -r1.23 direntry.h > --- direntry.h 24 Oct 2006 11:14:05 -0000 1.23 > +++ direntry.h 7 Aug 2007 11:51:16 -0000 > @@ -137,6 +137,10 @@ > struct msdosfsmount; >=20 > +void mbnambuf_acquire(void); > +void mbnambuf_create(void); > +void mbnambuf_destroy(void); > char *mbnambuf_flush(struct dirent *dp); > void mbnambuf_init(void); > +void mbnambuf_release(void); > void mbnambuf_write(char *name, int id); > int dos2unixfn(u_char dn[11], u_char *un, int lower, > Index: msdosfs_conv.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/sys/fs/msdosfs/msdosfs_conv.c,v > retrieving revision 1.52 > diff -u -2 -r1.52 msdosfs_conv.c > --- msdosfs_conv.c 7 Aug 2007 02:11:16 -0000 1.52 > +++ msdosfs_conv.c 7 Aug 2007 12:18:03 -0000 > @@ -53,6 +53,9 @@ > #include > #include > +#include > #include > #include > +#include > +#include >=20 > #include > @@ -68,4 +71,5 @@ > static u_int16_t unix2winchr(const u_char **, size_t *, int, struct=20 > msdosfsmount *); >=20 > +static struct sx nambuf_lock; > static char *nambuf_ptr; > static size_t nambuf_len; > @@ -1038,6 +1042,36 @@ >=20 > /* > - * Initialize the temporary concatenation buffer (once) and mark it as > - * empty on subsequent calls. > + * nambuf is static, so it must be locked for exclusive access even in t= he > + * non-SMP case, since although msdosfs is Giant-locked, calls like brea= d() > + * which can block are made while nambuf is in use. > + */ > +void > +mbnambuf_acquire(void) > +{ > + > + sx_xlock(&nambuf_lock); > +} > + > +void > +mbnambuf_create(void) > +{ > + > + KASSERT(nambuf_ptr =3D=3D NULL, ("mbnambuf_create: already created")); > + nambuf_ptr =3D malloc(MAXNAMLEN + 1, M_MSDOSFSMNT, M_WAITOK); > + nambuf_ptr[MAXNAMLEN] =3D '\0'; > + sx_init(&nambuf_lock, "mbnambuf"); > +} > + > +void > +mbnambuf_destroy(void) > +{ > + > + free(nambuf_ptr, M_MSDOSFSMNT); > + nambuf_ptr =3D NULL; > + sx_destroy(&nambuf_lock); > +} > + > +/* > + * Mark the temporary concatenation buffer as empty. > */ > void > @@ -1045,12 +1079,15 @@ > { >=20 > - if (nambuf_ptr =3D=3D NULL) {=20 > - nambuf_ptr =3D malloc(MAXNAMLEN + 1, M_MSDOSFSMNT, M_WAITOK); > - nambuf_ptr[MAXNAMLEN] =3D '\0'; > - } > nambuf_len =3D 0; > nambuf_last_id =3D -1; > } >=20 > +void > +mbnambuf_release(void) > +{ > + > + sx_xunlock(&nambuf_lock); > +} > + > /* > * Fill out our concatenation buffer with the given substring, at the=20 > offset > Index: msdosfs_lookup.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/sys/fs/msdosfs/msdosfs_lookup.c,v > retrieving revision 1.50 > diff -u -2 -r1.50 msdosfs_lookup.c > --- msdosfs_lookup.c 7 Aug 2007 02:25:56 -0000 1.50 > +++ msdosfs_lookup.c 7 Aug 2007 11:51:16 -0000 > @@ -186,4 +186,5 @@ > */ > tdp =3D NULL; > + mbnambuf_acquire(); > mbnambuf_init(); > /* > @@ -200,4 +201,5 @@ > if (error =3D=3D E2BIG) > break; > + mbnambuf_release(); > return (error); > } > @@ -205,4 +207,5 @@ > if (error) { > brelse(bp); > + mbnambuf_release(); > return (error); > } > @@ -234,4 +237,5 @@ > if (dep->deName[0] =3D=3D SLOT_EMPTY) { > brelse(bp); > + mbnambuf_release(); > goto notfound; > } > @@ -310,4 +314,5 @@ > } >=20 > + mbnambuf_release(); > goto found; > } > @@ -319,4 +324,5 @@ > brelse(bp); > } /* for (frcn =3D 0; ; frcn++) */ > + mbnambuf_release(); >=20 > notfound: > Index: msdosfs_vfsops.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/sys/fs/msdosfs/msdosfs_vfsops.c,v > retrieving revision 1.173 > diff -u -2 -r1.173 msdosfs_vfsops.c > --- msdosfs_vfsops.c 7 Aug 2007 03:38:36 -0000 1.173 > +++ msdosfs_vfsops.c 7 Aug 2007 12:07:37 -0000 > @@ -104,9 +104,5 @@ > static int mountmsdosfs(struct vnode *devvp, struct mount *mp, > struct thread *td); > -static vfs_fhtovp_t msdosfs_fhtovp; > -static vfs_mount_t msdosfs_mount; > static vfs_root_t msdosfs_root; > -static vfs_statfs_t msdosfs_statfs; > -static vfs_sync_t msdosfs_sync; > static vfs_unmount_t msdosfs_unmount; >=20 > @@ -939,11 +935,29 @@ > } >=20 > +static int > +msdosfs_init(struct vfsconf *vfsp) > +{ > + > + mbnambuf_create(); > + return (0); > +} > + > +static int > +msdosfs_uninit(struct vfsconf *vfsp) > +{ > + > + mbnambuf_destroy(); > + return (0); > +} > + > static struct vfsops msdosfs_vfsops =3D { > + .vfs_cmount =3D msdosfs_cmount, > .vfs_fhtovp =3D msdosfs_fhtovp, > + .vfs_init =3D msdosfs_init, > .vfs_mount =3D msdosfs_mount, > - .vfs_cmount =3D msdosfs_cmount, > .vfs_root =3D msdosfs_root, > .vfs_statfs =3D msdosfs_statfs, > .vfs_sync =3D msdosfs_sync, > + .vfs_uninit =3D msdosfs_uninit, > .vfs_unmount =3D msdosfs_unmount, > }; > Index: msdosfs_vnops.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > RCS file: /home/ncvs/src/sys/fs/msdosfs/msdosfs_vnops.c,v > retrieving revision 1.178 > diff -u -2 -r1.178 msdosfs_vnops.c > --- msdosfs_vnops.c 7 Aug 2007 10:35:27 -0000 1.178 > +++ msdosfs_vnops.c 7 Aug 2007 11:55:27 -0000 > @@ -1630,4 +1630,5 @@ > } >=20 > + mbnambuf_acquire(); > mbnambuf_init(); > off =3D offset; > @@ -1646,10 +1647,11 @@ > if (error) { > brelse(bp); > - return (error); > + break; > } > n =3D min(n, blsize - bp->b_resid); > if (n =3D=3D 0) { > brelse(bp); > - return (EIO); > + error =3D EIO; > + break; > } >=20 > @@ -1765,4 +1767,6 @@ > } > out: > + mbnambuf_release(); > + > /* Subtract unused cookies */ > if (ap->a_ncookies) > %%% >=20 > Bruce --ISA6zNVXmTIvvkD5 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFGuKXDC3+MBN1Mb4gRAoTVAKCOgm0BH7z4eg8bFyNwNBsI3AXs4gCcDUIt j0zTe8jwWllTzfvTyRH0z/k= =/kNT -----END PGP SIGNATURE----- --ISA6zNVXmTIvvkD5--