On 11/01/16(Mon) 10:44, Mathieu - wrote:
> Martin Pieuchot wrote:
> > On 03/01/16(Sun) 23:10, Martin Pieuchot wrote:
> > > Reading files on msdos-formated USB sticks under OpenBSD is really slow.
> > > *One* of the reasons is that only one block is currently read-ahead if
> > > possible.
> > >
> > > Diff below converts msdosfs_read() to use bread_cluster() which at least
> > > double the transfer rate when reading sequential blocks here.
> > >
> > > When combined with the previous bread_cluster() diff, I get almost the
> > > same read performances as with the raw device.
> > >
> > > With a cheap USB device here, I have:
> > >
> > > Kernel: Max measure read speed:
> > >
> > > -current 3.2M
> > > -current+this diff 6.8M
> > > -current+this diff+bread_cluster 11.8M
> > > physio(9) 12.4M
> >
> > I forgot to mention that these tests were performed with a 64k blocks.
> >
> > Here's an updated diff that gets rid of the now unused 'de_lastr'
> > argument. It makes use of 'mp->mnt_stat.f_iosize' to reduce differences
> > with UFS and the old cluster code. Finally it renames some variables
> > from 'lbn' to 'cn' to better reflect what we're dealing with.
>
> Hi,
>
> I've been testing the two diff lately (this one + bread_cluster), i've
> seen no regression and I can confirm that it speeds up the reading here
> too (by a smaller factor though, but it's with shitty hardware).
Thanks for testing, anybody wants to ok the diff?
> > Index: msdosfs/denode.h
> > ===================================================================
> > RCS file: /cvs/src/sys/msdosfs/denode.h,v
> > retrieving revision 1.27
> > diff -u -p -r1.27 denode.h
> > --- msdosfs/denode.h 23 Oct 2015 10:45:31 -0000 1.27
> > +++ msdosfs/denode.h 7 Jan 2016 16:36:08 -0000
> > @@ -142,7 +142,6 @@ struct denode {
> > struct vnode *de_devvp; /* vnode of blk dev we live on */
> > uint32_t de_flag; /* flag bits */
> > dev_t de_dev; /* device where direntry lives */
> > - daddr_t de_lastr;
> > uint32_t de_dirclust; /* cluster of the directory file containing
> > this entry */
> > uint32_t de_diroffset; /* offset of this entry in the directory
> > cluster */
> > uint32_t de_fndoffset; /* offset of found dir entry */
> > Index: msdosfs/msdosfs_vnops.c
> > ===================================================================
> > RCS file: /cvs/src/sys/msdosfs/msdosfs_vnops.c,v
> > retrieving revision 1.104
> > diff -u -p -r1.104 msdosfs_vnops.c
> > --- msdosfs/msdosfs_vnops.c 23 Oct 2015 18:04:37 -0000 1.104
> > +++ msdosfs/msdosfs_vnops.c 7 Jan 2016 16:36:55 -0000
> > @@ -77,13 +77,13 @@
> >
> > static uint32_t fileidhash(uint64_t);
> >
> > +int msdosfs_bmaparray(struct vnode *, daddr_t, daddr_t *, int *);
> > int msdosfs_kqfilter(void *);
> > int filt_msdosfsread(struct knote *, long);
> > int filt_msdosfswrite(struct knote *, long);
> > int filt_msdosfsvnode(struct knote *, long);
> > void filt_msdosfsdetach(struct knote *);
> >
> > -
> > /*
> > * Some general notes:
> > *
> > @@ -511,18 +511,15 @@ int
> > msdosfs_read(void *v)
> > {
> > struct vop_read_args *ap = v;
> > - int error = 0;
> > - uint32_t diff;
> > - int blsize;
> > - int isadir;
> > - uint32_t n;
> > - long on;
> > - daddr_t lbn, rablock, rablkno;
> > - struct buf *bp;
> > struct vnode *vp = ap->a_vp;
> > struct denode *dep = VTODE(vp);
> > struct msdosfsmount *pmp = dep->de_pmp;
> > struct uio *uio = ap->a_uio;
> > + int isadir, error = 0;
> > + uint32_t n, diff, size;
> > + struct buf *bp;
> > + daddr_t cn;
> > + long on;
> >
> > /*
> > * If they didn't ask for any data, then we are done.
> > @@ -537,7 +534,8 @@ msdosfs_read(void *v)
> > if (uio->uio_offset >= dep->de_FileSize)
> > return (0);
> >
> > - lbn = de_cluster(pmp, uio->uio_offset);
> > + cn = de_cluster(pmp, uio->uio_offset);
> > + size = pmp->pm_bpcluster;
> > on = uio->uio_offset & pmp->pm_crbomask;
> > n = min((uint32_t) (pmp->pm_bpcluster - on), uio->uio_resid);
> >
> > @@ -550,31 +548,21 @@ msdosfs_read(void *v)
> > if (diff < n)
> > n = diff;
> >
> > - /* convert cluster # to block # if a directory */
> > - if (isadir) {
> > - error = pcbmap(dep, lbn, &lbn, 0, &blsize);
> > - if (error)
> > - return (error);
> > - }
> > /*
> > * If we are operating on a directory file then be sure to
> > * do i/o with the vnode for the filesystem instead of the
> > * vnode for the directory.
> > */
> > if (isadir) {
> > - error = bread(pmp->pm_devvp, lbn, blsize, &bp);
> > + error = pcbmap(dep, cn, &cn, 0, &size);
> > + if (error)
> > + return (error);
> > + error = bread(pmp->pm_devvp, cn, size, &bp);
> > } else {
> > - rablock = lbn + 1;
> > - rablkno = de_cn2bn(pmp, rablock);
> > - if (dep->de_lastr + 1 == lbn &&
> > - de_cn2off(pmp, rablock) < dep->de_FileSize)
> > - error = breadn(vp, de_cn2bn(pmp, lbn),
> > - pmp->pm_bpcluster, &rablkno,
> > - &pmp->pm_bpcluster, 1, &bp);
> > + if (de_cn2off(pmp, cn + 1) >= dep->de_FileSize)
> > + error = bread(vp, cn, size, &bp);
> > else
> > - error = bread(vp, de_cn2bn(pmp, lbn),
> > - pmp->pm_bpcluster, &bp);
> > - dep->de_lastr = lbn;
> > + error = bread_cluster(vp, cn, size, &bp);
> > }
> > n = min(n, pmp->pm_bpcluster - bp->b_resid);
> > if (error) {
> > @@ -604,7 +592,7 @@ msdosfs_write(void *v)
> > uint32_t osize;
> > int error = 0;
> > uint32_t count, lastcn;
> > - daddr_t bn;
> > + daddr_t cn;
> > struct buf *bp;
> > int ioflag = ap->a_ioflag;
> > struct uio *uio = ap->a_uio;
> > @@ -680,32 +668,34 @@ msdosfs_write(void *v)
> > lastcn = de_clcount(pmp, osize) - 1;
> >
> > do {
> > - if (de_cluster(pmp, uio->uio_offset) > lastcn) {
> > + croffset = uio->uio_offset & pmp->pm_crbomask;
> > + cn = de_cluster(pmp, uio->uio_offset);
> > +
> > + if (cn > lastcn) {
> > error = ENOSPC;
> > break;
> > }
> >
> > - bn = de_blk(pmp, uio->uio_offset);
> > - if ((uio->uio_offset & pmp->pm_crbomask) == 0
> > - && (de_blk(pmp, uio->uio_offset + uio->uio_resid) >
> > de_blk(pmp, uio->uio_offset)
> > - || uio->uio_offset + uio->uio_resid >=
> > dep->de_FileSize)) {
> > + if (croffset == 0 &&
> > + (de_cluster(pmp, uio->uio_offset + uio->uio_resid) > cn ||
> > + (uio->uio_offset + uio->uio_resid) >= dep->de_FileSize)) {
> > /*
> > * If either the whole cluster gets written,
> > * or we write the cluster from its start beyond EOF,
> > * then no need to read data from disk.
> > */
> > - bp = getblk(thisvp, bn, pmp->pm_bpcluster, 0, 0);
> > + bp = getblk(thisvp, cn, pmp->pm_bpcluster, 0, 0);
> > clrbuf(bp);
> > /*
> > * Do the bmap now, since pcbmap needs buffers
> > * for the fat table. (see msdosfs_strategy)
> > */
> > if (bp->b_blkno == bp->b_lblkno) {
> > - error = pcbmap(dep,
> > - de_bn2cn(pmp, bp->b_lblkno),
> > - &bp->b_blkno, 0, 0);
> > + error = pcbmap(dep, bp->b_lblkno, &cn, 0, 0);
> > if (error)
> > bp->b_blkno = -1;
> > + else
> > + bp->b_blkno = cn;
> > }
> > if (bp->b_blkno == -1) {
> > brelse(bp);
> > @@ -715,16 +705,16 @@ msdosfs_write(void *v)
> > }
> > } else {
> > /*
> > - * The block we need to write into exists, so read it
> > in.
> > + * The block we need to write into exists, so
> > + * read it in.
> > */
> > - error = bread(thisvp, bn, pmp->pm_bpcluster, &bp);
> > + error = bread(thisvp, cn, pmp->pm_bpcluster, &bp);
> > if (error) {
> > brelse(bp);
> > break;
> > }
> > }
> >
> > - croffset = uio->uio_offset & pmp->pm_crbomask;
> > n = min(uio->uio_resid, pmp->pm_bpcluster - croffset);
> > if (uio->uio_offset + n > dep->de_FileSize) {
> > dep->de_FileSize = uio->uio_offset + n;
> > @@ -1756,7 +1746,7 @@ msdosfs_islocked(void *v)
> >
> > /*
> > * vp - address of vnode file the file
> > - * bn - which cluster we are interested in mapping to a filesystem block
> > number.
> > + * bn - which cluster we are interested in mapping to a filesystem block
> > number
> > * vpp - returns the vnode for the block special file holding the
> > filesystem
> > * containing the file of interest
> > * bnp - address of where to return the filesystem relative block number
> > @@ -1766,19 +1756,51 @@ msdosfs_bmap(void *v)
> > {
> > struct vop_bmap_args *ap = v;
> > struct denode *dep = VTODE(ap->a_vp);
> > - struct msdosfsmount *pmp = dep->de_pmp;
> >
> > if (ap->a_vpp != NULL)
> > *ap->a_vpp = dep->de_devvp;
> > if (ap->a_bnp == NULL)
> > return (0);
> > - if (ap->a_runp) {
> > +
> > + return (msdosfs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, ap->a_runp));
> > +}
> > +
> > +int
> > +msdosfs_bmaparray(struct vnode *vp, daddr_t cn, daddr_t *bnp, int *runp)
> > +{
> > + struct denode *dep = VTODE(vp);
> > + struct msdosfsmount *pmp = dep->de_pmp;
> > + struct mount *mp;
> > + int error, maxrun = 0, run;
> > + daddr_t daddr;
> > +
> > + mp = vp->v_mount;
> > +
> > + if (runp) {
> > /*
> > - * Sequential clusters should be counted here.
> > + * XXX
> > + * If MAXBSIZE is the largest transfer the disks can handle,
> > + * we probably want maxrun to be 1 block less so that we
> > + * don't create a block larger than the device can handle.
> > */
> > - *ap->a_runp = 0;
> > + *runp = 0;
> > + maxrun = min(MAXBSIZE / mp->mnt_stat.f_iosize - 1,
> > + pmp->pm_maxcluster - cn);
> > }
> > - return (pcbmap(dep, de_bn2cn(pmp, ap->a_bn), ap->a_bnp, 0, 0));
> > +
> > + if ((error = pcbmap(dep, cn, bnp, 0, 0)) != 0)
> > + return (error);
> > +
> > + for (run = 1; run <= maxrun; run++) {
> > + error = pcbmap(dep, cn + run, &daddr, 0, 0);
> > + if (error != 0 || (daddr != *bnp + de_cn2bn(pmp, run)))
> > + break;
> > + }
> > +
> > + if (runp)
> > + *runp = run - 1;
> > +
> > + return (0);
> > }
> >
> > int
> > @@ -1800,8 +1822,7 @@ msdosfs_strategy(void *v)
> > * don't allow files with holes, so we shouldn't ever see this.
> > */
> > if (bp->b_blkno == bp->b_lblkno) {
> > - error = pcbmap(dep, de_bn2cn(dep->de_pmp, bp->b_lblkno),
> > - &bp->b_blkno, 0, 0);
> > + error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno, 0, 0);
> > if (error)
> > bp->b_blkno = -1;
> > if (bp->b_blkno == -1)
> >
>
