Subversion Repositories planix.SVN

Rev

Blame | Last modification | View Log | RSS feed

#include <sys/param.h>
#include <sys/sockio.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <sys/protosw.h>
#include <sys/syslog.h>

#include <netinet/in.h>
#include <netinet/tcp.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_zone.h>
#include <vm/vm_prot.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>

#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>

#include <9fs/bitstring.h>
#include <9fs/9p.h>
#include <9fs/9auth.h>
#include <9fs/9fs.h>

static struct buf *u9fs_getcacheblk __P((struct vnode *vp, daddr_t bn, int size, struct proc *p));
static void u9fs_prot_buf __P((struct buf *bp, int off, int n));

/*
 * Vnode op for read using bio
 */
int
u9fs_bioread(vp, uio, ioflag, cred, getpages)
        register struct vnode *vp;
        register struct uio *uio;
        int ioflag;
        struct ucred *cred;
        int getpages;
{
        register struct u9fsnode *np = VTOU9FS(vp);
        register int biosize;
        off_t diff;
        struct buf *bp = 0;
        struct proc *p;
        struct u9fsmount *nmp = VFSTOU9FS(vp->v_mount);
        daddr_t lbn;
        int error = 0, n = 0, on = 0, bufsize, not_readin;

        if (uio->uio_resid == 0)
                return (0);
        if (uio->uio_offset < 0)
                return (EINVAL);
        p = uio->uio_procp;
        if (vp->v_type != VDIR &&
            (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
                return (EFBIG);
        biosize = vp->v_mount->mnt_stat.f_iosize;
#if 0
        if( np->n_qid.vers ) { /* in cache, check revision */
          error = VOP_GETATTR(vp, &vattr, cred, p);
          if( error )
            return error;
          if( np->n_qid.vers != np->n_dir.dir_qid.vers ) {
            /* content changed */
            u9fs_vinvalbuf(vp, V_SAVE, cred, p, 1);
          }
        }
#endif
        do {
            switch (vp->v_type) {
            case VREG:
                lbn = uio->uio_offset / biosize;
                on = uio->uio_offset & (biosize - 1);
                not_readin = 1;

#if 0
                /*
                 * Start the read ahead(s), as required.
                 */
                if (u9fs_numasync > 0 && nmp->nm_readahead > 0) {
                    for (nra = 0; nra < nmp->nm_readahead &&
                        (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) {
                        rabn = lbn + 1 + nra;
                        if (!incore(vp, rabn)) {
                            rabp = u9fs_getcacheblk(vp, rabn, biosize, p);
                            if (!rabp)
                                return (EINTR);
                            if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
                                rabp->b_flags |= (B_READ | B_ASYNC);
                                vfs_busy_pages(rabp, 0);
                                if (u9fs_asyncio(rabp, cred)) {
                                    rabp->b_flags |= B_INVAL|B_ERROR;
                                    vfs_unbusy_pages(rabp);
                                    brelse(rabp);
                                }
                            } else
                                brelse(rabp);
                        }
                    }
                }
#endif

                /*
                 * If the block is in the cache and has the required data
                 * in a valid region, just copy it out.
                 * Otherwise, get the block and write back/read in,
                 * as required.
                 */
again:
                bufsize = biosize;
                if ((off_t)(lbn + 1) * biosize > np->n_size && 
                    (off_t)(lbn + 1) * biosize - np->n_size < biosize) {
                        bufsize = np->n_size - (off_t)lbn * biosize;
                        bufsize = (bufsize + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
                }
                bp = u9fs_getcacheblk(vp, lbn, bufsize, p);
                if (!bp)
                        return (EINTR);
                /*
                 * If we are being called from u9fs_getpages, we must
                 * make sure the buffer is a vmio buffer.  The vp will
                 * already be setup for vmio but there may be some old
                 * non-vmio buffers attached to it.
                 */
                if (getpages && !(bp->b_flags & B_VMIO)) {
#ifdef DIAGNOSTIC
                        printf("u9fs_bioread: non vmio buf found, discarding\n");
#endif
                        bp->b_flags |= B_NOCACHE;
                        if (bp->b_dirtyend > 0) {
                                if ((bp->b_flags & B_DELWRI) == 0)
                                        panic("u9fsbioread");
                                if (VOP_BWRITE(bp) == EINTR)
                                        return (EINTR);
                        } else
                                brelse(bp);
                        goto again;
                }
                if ((bp->b_flags & B_CACHE) == 0) {
                    bp->b_flags |= B_READ;
                    bp->b_flags &= ~(B_DONE | B_ERROR | B_INVAL);
                    not_readin = 0;
                    vfs_busy_pages(bp, 0);
                    error = u9fs_doio(bp, cred, p);
                    if (error) {
                        brelse(bp);
                        return (error);
                    }
                    np->n_qid.vers = np->n_dir.dir_qid.vers;
                }
                if (bufsize > on) {
                        n = min((unsigned)(bufsize - on), uio->uio_resid);
                } else {
                        n = 0;
                }
                diff = np->n_size - uio->uio_offset;
                if (diff < n)
                        n = diff;
                if (not_readin && n > 0) {
                        if (on < bp->b_validoff || (on + n) > bp->b_validend) {
                                bp->b_flags |= B_NOCACHE;
                                if (bp->b_dirtyend > 0) {
                                    if ((bp->b_flags & B_DELWRI) == 0)
                                        panic("u9fsbioread");
                                    if (VOP_BWRITE(bp) == EINTR)
                                        return (EINTR);
                                } else
                                    brelse(bp);
                                goto again;
                        }
                }
                vp->v_lastr = lbn;
                diff = (on >= bp->b_validend) ? 0 : (bp->b_validend - on);
                if (diff < n)
                        n = diff;
                break;
            case VDIR:
                biosize = nmp->nm_readdirsize;
                lbn = (uoff_t)uio->uio_offset / biosize;
                on = uio->uio_offset % biosize;
                bp = u9fs_getcacheblk(vp, lbn, biosize, p);
                if (!bp)
                    return (EINTR);
                if ((bp->b_flags & B_CACHE) == 0) {
                    bp->b_flags |= B_READ;
                    vfs_busy_pages(bp, 0);
                    error = u9fs_doio(bp, cred, p);
                    if (error) {
                            brelse(bp);
                    }
                    if (error)
                            return (error);
                    np->n_qid.vers = np->n_dir.dir_qid.vers;
                }

                /*
                 * Make sure we use a signed variant of min() since
                 * the second term may be negative.
                 */
                n = lmin(uio->uio_resid, biosize - bp->b_resid - on);
                break;
            default:
                printf(" u9fs_bioread: type %x unexpected\n",vp->v_type);
                break;
            };

            if (n > 0) {
                    error = uiomove(bp->b_data + on, (int)n, uio);
            }
            brelse(bp);
        } while (error == 0 && uio->uio_resid > 0 && n > 0);
        return (error);
}

/*
 * Vnode op for write using bio
 */
int
u9fs_biowrite(vp, uio, ioflag, cred)
     register struct vnode *vp;
     register struct uio *uio;
     register int  ioflag;
     register struct ucred *cred;
{
  register int biosize;
  struct proc *p = uio->uio_procp;
  struct u9fsnode *np = VTOU9FS(vp);
  struct buf *bp;
  struct vattr vattr;
  struct u9fsmount *nmp = VFSTOU9FS(vp->v_mount);
  daddr_t lbn;
  int bufsize;
  int n, on, error = 0;

  if (ioflag & (IO_APPEND | IO_SYNC)) {
    if (ioflag & IO_APPEND) {
      error = VOP_GETATTR(vp, &vattr, cred, p);
      if (error)
        return (error);
      uio->uio_offset = np->n_size;
    }
  }
  if (uio->uio_offset < 0)
    return (EINVAL);
  if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
    return (EFBIG);
  if (uio->uio_resid == 0)
    return (0);

        /*
         * I use nm_rsize, not nm_wsize so that all buffer cache blocks
         * will be the same size within a filesystem. nfs_writerpc will
         * still use nm_wsize when sizing the rpc's.
         */
        biosize = vp->v_mount->mnt_stat.f_iosize;
        do {
                lbn = uio->uio_offset / biosize;
                on = uio->uio_offset & (biosize-1);
                n = min((unsigned)(biosize - on), uio->uio_resid);
                if (uio->uio_offset + n > np->n_size) {
                        np->n_size = uio->uio_offset + n;
                        vnode_pager_setsize(vp, np->n_size);
                }
                bufsize = biosize;
                if ((off_t)(lbn + 1) * biosize > np->n_size) {
                        bufsize = np->n_size - (off_t)lbn * biosize;
                        bufsize = (bufsize + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
                }
                bp = u9fs_getcacheblk(vp, lbn, bufsize, p);
                if (!bp)
                        return (EINTR);
                if (bp->b_wcred == NOCRED) {
                        crhold(cred);
                        bp->b_wcred = cred;
                }

                error = uiomove((char *)bp->b_data + on, n, uio);
                if (error) {
                        bp->b_flags |= B_ERROR;
                        brelse(bp);
                        return (error);
                }

                /*
                 * This will keep the buffer and mmaped regions more coherent.
                 */
                u9fs_prot_buf(bp, on, n);
                bp->b_dirtyoff = on;
                bp->b_dirtyend = on + n;

                if (bp->b_validend == 0 || bp->b_validend < bp->b_dirtyoff ||
                    bp->b_validoff > bp->b_dirtyend) {
                  /* XXX: destroys our read cache if not overlapping */
                  /* two choice: none implemented
                     1> keep the bigger(smaller) piece
                     2> read the missing segment                     
                  */
                        bp->b_validoff = bp->b_dirtyoff;
                        bp->b_validend = bp->b_dirtyend;
                } else {
                        bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff);
                        bp->b_validend = max(bp->b_validend, bp->b_dirtyend);
                }

                error = bwrite(bp);
                if( error ) {
                  bp->b_flags |= B_ERROR;
                  /* brelse(bp); */
                  return error;           
                }
        } while (uio->uio_resid > 0 && n > 0);
        return 0;
}

/*
 * Do an I/O operation to/from a cache block. This may be called
 * synchronously or from an u9fsiod.
 */
int
u9fs_doio(bp, cr, p)
        register struct buf *bp;
        struct ucred *cr;
        struct proc *p;
{
        register struct uio *uiop;
        register struct vnode *vp;
        struct u9fsnode *np;
        struct u9fsmount *nmp;
        int error = 0, diff, len;
        struct uio uio;
        struct iovec io;

        vp = bp->b_vp;
        np = VTOU9FS(vp);
        nmp = VFSTOU9FS(vp->v_mount);
        uiop = &uio;
        uiop->uio_iov = &io;
        uiop->uio_iovcnt = 1;
        uiop->uio_segflg = UIO_SYSSPACE;
        uiop->uio_procp = p;

        if (bp->b_flags & B_READ ) {
            io.iov_len = uiop->uio_resid = bp->b_bcount;
            io.iov_base = bp->b_data;
            uiop->uio_rw = UIO_READ;
            switch (vp->v_type) {
            case VREG:
                uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
                error = u9fs_readrpc(vp, uiop, cr);
                if (!error) {
                    bp->b_validoff = 0;
                    if (uiop->uio_resid) {
                        /*
                         * If len > 0, there is a hole in the file and
                         * no writes after the hole have been pushed to
                         * the server yet.
                         * Just zero fill the rest of the valid area.
                         */
                        diff = bp->b_bcount - uiop->uio_resid;
                        len = np->n_size - (((u_quad_t)bp->b_blkno) * DEV_BSIZE
                                + diff);
                        if (len > 0) {
                            len = min(len, uiop->uio_resid);
                            bzero((char *)bp->b_data + diff, len);
                            bp->b_validend = diff + len;
                        } else
                            bp->b_validend = diff;
                    } else
                        bp->b_validend = bp->b_bcount;
                }
                break;
            case VDIR:
                uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * nmp->nm_readdirsize;
                error = u9fs_readdirrpc(vp, uiop, cr);
                if (error == 0 && uiop->uio_resid == bp->b_bcount)
                  bp->b_flags |= B_INVAL;
                break;
            default:
                printf("u9fs_doio:  type %x unexpected\n",vp->v_type);
                break;
            };
            if (error) {
                bp->b_flags |= B_ERROR;
                bp->b_error = error;
            }
        } else {
            if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
                bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;

            if (bp->b_dirtyend > bp->b_dirtyoff) {
                io.iov_len = uiop->uio_resid = bp->b_dirtyend
                    - bp->b_dirtyoff;
                uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
                    + bp->b_dirtyoff;
                io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
                uiop->uio_rw = UIO_WRITE;
                bp->b_flags |= B_WRITEINPROG;
                error = u9fs_writerpc(vp, uiop, cr);
                bp->b_flags &= ~B_WRITEINPROG;

                if (error) {
                  bp->b_flags |= B_ERROR;
                  bp->b_error = np->n_error = error;
                  np->n_flag |= NWRITEERR;
                }
                bp->b_dirtyoff = bp->b_dirtyend = 0;
            } else {
                bp->b_resid = 0;
                biodone(bp);
                return (0);
            }
        }
        bp->b_resid = uiop->uio_resid;
        biodone(bp);
        return error;
}

/*
 * Get an u9fs cache block.
 * Allocate a new one if the block isn't currently in the cache
 * and return the block marked busy. If the calling process is
 * interrupted by a signal for an interruptible mount point, return
 * NULL.
 */
static struct buf *
u9fs_getcacheblk(vp, bn, size, p)
        struct vnode *vp;
        daddr_t bn;
        int size;
        struct proc *p;
{
        register struct buf *bp;
        struct mount *mp;
        struct u9fsmount *nmp;

        mp = vp->v_mount;
        nmp = VFSTOU9FS(mp);

        if (nmp->nm_flag & U9FSMNT_INT) {
                bp = getblk(vp, bn, size, PCATCH, 0);
                while (bp == (struct buf *)0) {
                        if (u9fs_sigintr(nmp, p))
                                return ((struct buf *)0);
                        bp = getblk(vp, bn, size, 0, 2 * hz);
                }
        } else
                bp = getblk(vp, bn, size, 0, 0);

        if (vp->v_type == VREG) {
                int biosize;
                biosize = mp->mnt_stat.f_iosize;
                bp->b_blkno = bn * (biosize / DEV_BSIZE);
        }

        return (bp);
}

static void
u9fs_prot_buf(bp, off, n)
        struct buf *bp;
        int off;
        int n;
{
        int pindex, boff, end;

        if ((bp->b_flags & B_VMIO) == 0)
                return;

        end = round_page(off + n);
        for (boff = trunc_page(off); boff < end; boff += PAGE_SIZE) {
                pindex = boff >> PAGE_SHIFT;
                vm_page_protect(bp->b_pages[pindex], VM_PROT_NONE);
        }
}

/*
 * Flush and invalidate all dirty buffers. If another process is already
 * doing the flush, just wait for completion.
 */
int
u9fs_vinvalbuf(vp, flags, cred, p, intrflg)
        struct vnode *vp;
        int flags;
        struct ucred *cred;
        struct proc *p;
        int intrflg;
{
        register struct u9fsnode *np = VTOU9FS(vp);
        struct u9fsmount *nmp = VFSTOU9FS(vp->v_mount);
        int error = 0, slpflag, slptimeo;

        if (vp->v_flag & VXLOCK) {
                return (0);
        }

        if ((nmp->nm_flag & U9FSMNT_INT) == 0)
                intrflg = 0;
        if (intrflg) {
                slpflag = PCATCH;
                slptimeo = 2 * hz;
        } else {
                slpflag = 0;
                slptimeo = 0;
        }
        /*
         * First wait for any other process doing a flush to complete.
         */
        while (np->n_flag & NFLUSHINPROG) {
                np->n_flag |= NFLUSHWANT;
                error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "u9fsvinval",
                        slptimeo);
                if (error && intrflg && u9fs_sigintr(nmp, p))
                        return (EINTR);
        }

        /*
         * Now, flush as required.
         */
        np->n_flag |= NFLUSHINPROG;
        error = vinvalbuf(vp, flags, cred, p, slpflag, 0);
        while (error) {
                if (intrflg && u9fs_sigintr(nmp, p)) {
                        np->n_flag &= ~NFLUSHINPROG;
                        if (np->n_flag & NFLUSHWANT) {
                                np->n_flag &= ~NFLUSHWANT;
                                wakeup((caddr_t)&np->n_flag);
                        }
                        return (EINTR);
                }
                error = vinvalbuf(vp, flags, cred, p, 0, slptimeo);
        }
        np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
        if (np->n_flag & NFLUSHWANT) {
                np->n_flag &= ~NFLUSHWANT;
                wakeup((caddr_t)&np->n_flag);
        }
        return (0);
}