FreeBSD/Linux Kernel Cross Reference
sys/fs/coda/coda_vfsops.c

     /*-
      *             Coda: an Experimental Distributed File System
      *                              Release 3.1
      * 
      *           Copyright (c) 1987-1998 Carnegie Mellon University
      *                          All Rights Reserved
      * 
      * Permission  to  use, copy, modify and distribute this software and its
      * documentation is hereby granted,  provided  that  both  the  copyright
     * notice  and  this  permission  notice  appear  in  all  copies  of the
     * software, derivative works or  modified  versions,  and  any  portions
     * thereof, and that both notices appear in supporting documentation, and
     * that credit is given to Carnegie Mellon University  in  all  documents
     * and publicity pertaining to direct or indirect use of this code or its
     * derivatives.
     * 
     * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS  KNOWN  TO  HAVE  BUGS,
     * SOME  OF  WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON ALLOWS
     * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.   CARNEGIE  MELLON
     * DISCLAIMS  ANY  LIABILITY  OF  ANY  KIND  FOR  ANY  DAMAGES WHATSOEVER
     * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE  OR  OF
     * ANY DERIVATIVE WORK.
     * 
     * Carnegie  Mellon  encourages  users  of  this  software  to return any
     * improvements or extensions that  they  make,  and  to  grant  Carnegie
     * Mellon the rights to redistribute these changes without encumbrance.
     * 
     *      @(#) src/sys/cfs/coda_vfsops.c,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
     */
    /*-
     * Mach Operating System
     * Copyright (c) 1989 Carnegie-Mellon University
     * All rights reserved.  The CMU software License Agreement specifies
     * the terms and conditions for use and redistribution.
     */
    
    /*
     * This code was written for the Coda filesystem at Carnegie Mellon
     * University.  Contributers include David Steere, James Kistler, and
     * M. Satyanarayanan.  
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/conf.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/mount.h>
    #include <sys/namei.h>
    #include <sys/proc.h>
    
    #include <fs/coda/coda.h>
    #include <fs/coda/cnode.h>
    #include <fs/coda/coda_vfsops.h>
    #include <fs/coda/coda_venus.h>
    #include <fs/coda/coda_subr.h>
    #include <fs/coda/coda_opstats.h>
    
    MALLOC_DEFINE(M_CODA, "coda", "Various Coda Structures");
    
    int codadebug = 0;
    int coda_vfsop_print_entry = 0;
    #define ENTRY    if(coda_vfsop_print_entry) myprintf(("Entered %s\n",__func__))
    
    struct vnode *coda_ctlvp;
    
    /* structure to keep statistics of internally generated/satisfied calls */
    
    struct coda_op_stats coda_vfsopstats[CODA_VFSOPS_SIZE];
    
    #define MARK_ENTRY(op) (coda_vfsopstats[op].entries++)
    #define MARK_INT_SAT(op) (coda_vfsopstats[op].sat_intrn++)
    #define MARK_INT_FAIL(op) (coda_vfsopstats[op].unsat_intrn++)
    #define MARK_INT_GEN(op) (coda_vfsopstats[op].gen_intrn++)
    
    int
    coda_vfsopstats_init(void)
    {
            register int i;
            
            for (i=0;i<CODA_VFSOPS_SIZE;i++) {
                    coda_vfsopstats[i].opcode = i;
                    coda_vfsopstats[i].entries = 0;
                    coda_vfsopstats[i].sat_intrn = 0;
                    coda_vfsopstats[i].unsat_intrn = 0;
                    coda_vfsopstats[i].gen_intrn = 0;
            }
            
            return 0;
    }
    
    static const char *coda_opts[] = { "from", NULL };
    /*
     * cfs mount vfsop
     * Set up mount info record and attach it to vfs struct.
    */
   /*ARGSUSED*/
   int
   coda_mount(struct mount *vfsp, struct thread *td)
   {
       struct vnode *dvp;
       struct cnode *cp;
       struct cdev *dev;
       struct coda_mntinfo *mi;
       struct vnode *rootvp;
       CodaFid rootfid = INVAL_FID;
       CodaFid ctlfid = CTL_FID;
       int error;
       struct nameidata ndp;
       ENTRY;
       char *from;
   
       if (vfs_filteropt(vfsp->mnt_optnew, coda_opts))
           return (EINVAL);
   
       from = vfs_getopts(vfsp->mnt_optnew, "from", &error);
       if (error)
           return (error);
   
       coda_vfsopstats_init();
       coda_vnodeopstats_init();
       
       MARK_ENTRY(CODA_MOUNT_STATS);
       if (CODA_MOUNTED(vfsp)) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return(EBUSY);
       }
       
       /* Validate mount device.  Similar to getmdev(). */
       NDINIT(&ndp, LOOKUP, FOLLOW, UIO_SYSSPACE, from, td);
       error = namei(&ndp);
       dvp = ndp.ni_vp;
   
       if (error) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return (error);
       }
       if (dvp->v_type != VCHR) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           vrele(dvp);
           NDFREE(&ndp, NDF_ONLY_PNBUF);
           return(ENXIO);
       }
       dev = dvp->v_rdev;
       vrele(dvp);
       NDFREE(&ndp, NDF_ONLY_PNBUF);
   
       /*
        * Initialize the mount record and link it to the vfs struct
        */
       mi = dev2coda_mntinfo(dev);
       if (!mi) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           printf("Coda mount: %s is not a cfs device\n", from);
           return(ENXIO);
       }
       
       if (!VC_OPEN(&mi->mi_vcomm)) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return(ENODEV);
       }
       
       /* No initialization (here) of mi_vcomm! */
       vfsp->mnt_data = mi;
       vfs_getnewfsid (vfsp);
   
       mi->mi_vfsp = vfsp;
       mi->mi_started = 0;                 /* XXX See coda_root() */
       
       /*
        * Make a root vnode to placate the Vnode interface, but don't
        * actually make the CODA_ROOT call to venus until the first call
        * to coda_root in case a server is down while venus is starting.
        */
       cp = make_coda_node(&rootfid, vfsp, VDIR);
       rootvp = CTOV(cp);
       rootvp->v_vflag |= VV_ROOT;
           
       cp = make_coda_node(&ctlfid, vfsp, VREG);
       coda_ctlvp = CTOV(cp);
   
       /* Add vfs and rootvp to chain of vfs hanging off mntinfo */
       mi->mi_vfsp = vfsp;
       mi->mi_rootvp = rootvp;
       
       vfs_mountedfrom(vfsp, from);
       /* error is currently guaranteed to be zero, but in case some
          code changes... */
       CODADEBUG(1,
                myprintf(("coda_omount returned %d\n",error)););
       if (error)
           MARK_INT_FAIL(CODA_MOUNT_STATS);
       else
           MARK_INT_SAT(CODA_MOUNT_STATS);
       
       return(error);
   }
   
   int
   coda_unmount(vfsp, mntflags, td)
       struct mount *vfsp;
       int mntflags;
       struct thread *td;
   {
       struct coda_mntinfo *mi = vftomi(vfsp);
       int active, error = 0;
       
       ENTRY;
       MARK_ENTRY(CODA_UMOUNT_STATS);
       if (!CODA_MOUNTED(vfsp)) {
           MARK_INT_FAIL(CODA_UMOUNT_STATS);
           return(EINVAL);
       }
       
       if (mi->mi_vfsp == vfsp) {  /* We found the victim */
           if (!IS_UNMOUNTING(VTOC(mi->mi_rootvp)))
               return (EBUSY);     /* Venus is still running */
   
   #ifdef  DEBUG
           printf("coda_unmount: ROOT: vp %p, cp %p\n", mi->mi_rootvp, VTOC(mi->mi_rootvp));
   #endif
           vrele(mi->mi_rootvp);
           mi->mi_rootvp = NULL;
           vrele(coda_ctlvp);
           coda_ctlvp = NULL;
           active = coda_kill(vfsp, NOT_DOWNCALL);
           error = vflush(mi->mi_vfsp, 0, FORCECLOSE, td);
   #ifdef CODA_VERBOSE
           printf("coda_unmount: active = %d, vflush active %d\n", active, error);
   #endif
           error = 0;
           /* I'm going to take this out to allow lookups to go through. I'm
            * not sure it's important anyway. -- DCS 2/2/94
            */
           /* vfsp->VFS_DATA = NULL; */
   
           /* No more vfsp's to hold onto */
           mi->mi_vfsp = NULL;
   
           if (error)
               MARK_INT_FAIL(CODA_UMOUNT_STATS);
           else
               MARK_INT_SAT(CODA_UMOUNT_STATS);
   
           return(error);
       }
       return (EINVAL);
   }
   
   /*
    * find root of cfs
    */
   int
   coda_root(vfsp, flags, vpp, td)
           struct mount *vfsp;
           int flags;
           struct vnode **vpp;
           struct thread *td;
   {
       struct coda_mntinfo *mi = vftomi(vfsp);
       struct vnode **result;
       int error;
       struct proc *p = td->td_proc;
       CodaFid VFid;
       static const CodaFid invalfid = INVAL_FID;
    
       ENTRY;
       MARK_ENTRY(CODA_ROOT_STATS);
       result = NULL;
       
       if (vfsp == mi->mi_vfsp) {
           /*
            * Cache the root across calls. We only need to pass the request
            * on to Venus if the root vnode is the dummy we installed in
            * coda_omount() with all c_fid members zeroed.
            *
            * XXX In addition, we assume that the first call to coda_root()
            * is from vfs_omount()
            * (before the call to checkdirs()) and return the dummy root
            * node to avoid a deadlock. This bug is fixed in the Coda CVS
            * repository but not in any released versions as of 6 Mar 2003.
            */
           if (memcmp(&VTOC(mi->mi_rootvp)->c_fid, &invalfid,
               sizeof(CodaFid)) != 0 || mi->mi_started == 0)
               { /* Found valid root. */
                   *vpp = mi->mi_rootvp;
                   mi->mi_started = 1;
   
                   /* On Mach, this is vref.  On NetBSD, VOP_LOCK */
   #if     1
                   vref(*vpp);
                   vn_lock(*vpp, LK_EXCLUSIVE, td);
   #else
                   vget(*vpp, LK_EXCLUSIVE, td);
   #endif
                   MARK_INT_SAT(CODA_ROOT_STATS);
                   return(0);
               }
       }
   
       error = venus_root(vftomi(vfsp), td->td_ucred, p, &VFid);
   
       if (!error) {
           /*
            * Save the new rootfid in the cnode, and rehash the cnode into the
            * cnode hash with the new fid key.
            */
           coda_unsave(VTOC(mi->mi_rootvp));
           VTOC(mi->mi_rootvp)->c_fid = VFid;
           coda_save(VTOC(mi->mi_rootvp));
   
           *vpp = mi->mi_rootvp;
   #if     1
           vref(*vpp);
           vn_lock(*vpp, LK_EXCLUSIVE, td);
   #else
           vget(*vpp, LK_EXCLUSIVE, td);
   #endif
   
           MARK_INT_SAT(CODA_ROOT_STATS);
           goto exit;
       } else if (error == ENODEV || error == EINTR) {
           /* Gross hack here! */
           /*
            * If Venus fails to respond to the CODA_ROOT call, coda_call returns
            * ENODEV. Return the uninitialized root vnode to allow vfs
            * operations such as unmount to continue. Without this hack,
            * there is no way to do an unmount if Venus dies before a 
            * successful CODA_ROOT call is done. All vnode operations 
            * will fail.
            */
           *vpp = mi->mi_rootvp;
   #if     1
           vref(*vpp);
           vn_lock(*vpp, LK_EXCLUSIVE, td);
   #else
           vget(*vpp, LK_EXCLUSIVE, td);
   #endif
   
           MARK_INT_FAIL(CODA_ROOT_STATS);
           error = 0;
           goto exit;
       } else {
           CODADEBUG( CODA_ROOT, myprintf(("error %d in CODA_ROOT\n", error)); );
           MARK_INT_FAIL(CODA_ROOT_STATS);
                   
           goto exit;
       }
   
    exit:
       return(error);
   }
   
   /*
    * Get filesystem statistics.
    */
   int
   coda_nb_statfs(vfsp, sbp, td)
       register struct mount *vfsp;
       struct statfs *sbp;
       struct thread *td;
   {
       ENTRY;
   /*  MARK_ENTRY(CODA_STATFS_STATS); */
       if (!CODA_MOUNTED(vfsp)) {
   /*      MARK_INT_FAIL(CODA_STATFS_STATS);*/
           return(EINVAL);
       }
       
       /* XXX - what to do about f_flags, others? --bnoble */
       /* Below This is what AFS does
           #define NB_SFS_SIZ 0x895440
        */
       sbp->f_flags = 0;
       sbp->f_bsize = 8192; /* XXX */
       sbp->f_iosize = 8192; /* XXX */
   #define NB_SFS_SIZ 0x8AB75D
       sbp->f_blocks = NB_SFS_SIZ;
       sbp->f_bfree = NB_SFS_SIZ;
       sbp->f_bavail = NB_SFS_SIZ;
       sbp->f_files = NB_SFS_SIZ;
       sbp->f_ffree = NB_SFS_SIZ;
   /*  MARK_INT_SAT(CODA_STATFS_STATS); */
       return(0);
   }
   
   /*
    * Flush any pending I/O.
    */
   int
   coda_sync(vfsp, waitfor, td)
       struct mount *vfsp;
       int    waitfor;
       struct thread *td;
   {
       ENTRY;
       MARK_ENTRY(CODA_SYNC_STATS);
       MARK_INT_SAT(CODA_SYNC_STATS);
       return(0);
   }
   
   /* 
    * fhtovp is now what vget used to be in 4.3-derived systems.  For
    * some silly reason, vget is now keyed by a 32 bit ino_t, rather than
    * a type-specific fid.  
    */
   int
   coda_fhtovp(vfsp, fhp, nam, vpp, exflagsp, creadanonp)
       register struct mount *vfsp;    
       struct fid *fhp;
       struct mbuf *nam;
       struct vnode **vpp;
       int *exflagsp;
       struct ucred **creadanonp;
   {
       struct cfid *cfid = (struct cfid *)fhp;
       struct cnode *cp = 0;
       int error;
       struct thread *td = curthread; /* XXX -mach */
       struct proc *p = td->td_proc;
       CodaFid VFid;
       int vtype;
   
       ENTRY;
       
       MARK_ENTRY(CODA_VGET_STATS);
       /* Check for vget of control object. */
       if (IS_CTL_FID(&cfid->cfid_fid)) {
           *vpp = coda_ctlvp;
           vref(coda_ctlvp);
           MARK_INT_SAT(CODA_VGET_STATS);
           return(0);
       }
       
       error = venus_fhtovp(vftomi(vfsp), &cfid->cfid_fid, td->td_ucred, p, &VFid, &vtype);
       
       if (error) {
           CODADEBUG(CODA_VGET, myprintf(("vget error %d\n",error));)
               *vpp = (struct vnode *)0;
       } else {
           CODADEBUG(CODA_VGET, 
                    myprintf(("vget: %s type %d result %d\n",
                           coda_f2s(&VFid), vtype, error)); )          
           cp = make_coda_node(&VFid, vfsp, vtype);
           *vpp = CTOV(cp);
       }
       return(error);
   }
   
   /*
    * To allow for greater ease of use, some vnodes may be orphaned when
    * Venus dies.  Certain operations should still be allowed to go
    * through, but without propagating ophan-ness.  So this function will
    * get a new vnode for the file from the current run of Venus.  */
    
   int
   getNewVnode(vpp)
        struct vnode **vpp;
   {
       struct cfid cfid;
       struct coda_mntinfo *mi = vftomi((*vpp)->v_mount);
       
       ENTRY;
   
       cfid.cfid_len = (short)sizeof(CodaFid);
       cfid.cfid_fid = VTOC(*vpp)->c_fid;  /* Structure assignment. */
       /* XXX ? */
   
       /* We're guessing that if set, the 1st element on the list is a
        * valid vnode to use. If not, return ENODEV as venus is dead.
        */
       if (mi->mi_vfsp == NULL)
           return ENODEV;
       
       return coda_fhtovp(mi->mi_vfsp, (struct fid*)&cfid, NULL, vpp,
                         NULL, NULL);
   }
   
   #include <ufs/ufs/extattr.h>
   #include <ufs/ufs/quota.h>
   #include <ufs/ufs/ufsmount.h>
   /* get the mount structure corresponding to a given device.  Assume 
    * device corresponds to a UFS. Return NULL if no device is found.
    */ 
   struct mount *devtomp(dev)
       struct cdev *dev;
   {
       struct mount *mp;
      
       TAILQ_FOREACH(mp, &mountlist, mnt_list) {
           if (((VFSTOUFS(mp))->um_dev == dev)) {
               /* mount corresponds to UFS and the device matches one we want */
               return(mp); 
           }
       }
       /* mount structure wasn't found */ 
       return(NULL); 
   }
   
   struct vfsops coda_vfsops = {
       .vfs_mount =                coda_mount,
       .vfs_root =                 coda_root,
       .vfs_statfs =               coda_nb_statfs,
       .vfs_sync =                 coda_sync,
       .vfs_unmount =              coda_unmount,
   };
   
   VFS_SET(coda_vfsops, coda, VFCF_NETWORK);

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