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

     /*      $NetBSD: coda_vfsops.c,v 1.90 2022/03/28 12:37:46 riastradh Exp $       */
     
     /*
      *
      *             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.
     *
     *      @(#) cfs/coda_vfsops.c,v 1.1.1.1 1998/08/29 21:26:45 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 file system at Carnegie Mellon
     * University.  Contributers include David Steere, James Kistler, and
     * M. Satyanarayanan.
     */
    
    #include <sys/cdefs.h>
    __KERNEL_RCSID(0, "$NetBSD: coda_vfsops.c,v 1.90 2022/03/28 12:37:46 riastradh Exp $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/sysctl.h>
    #include <sys/malloc.h>
    #include <sys/conf.h>
    #include <sys/namei.h>
    #include <sys/dirent.h>
    #include <sys/mount.h>
    #include <sys/proc.h>
    #include <sys/select.h>
    #include <sys/kauth.h>
    #include <sys/module.h>
    
    #include <coda/coda.h>
    #include <coda/cnode.h>
    #include <coda/coda_vfsops.h>
    #include <coda/coda_venus.h>
    #include <coda/coda_subr.h>
    #include <coda/coda_opstats.h>
    /* for VN_RDEV */
    #include <miscfs/specfs/specdev.h>
    #include <miscfs/genfs/genfs.h>
     
    MODULE(MODULE_CLASS_VFS, coda, "vcoda");
    
    #define ENTRY if(coda_vfsop_print_entry) myprintf(("Entered %s\n",__func__))
    
    extern struct vnode *coda_ctlvp;
    extern struct coda_mntinfo coda_mnttbl[NVCODA]; /* indexed by minor device number */
    
    /* 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 MRAK_INT_GEN(op) (coda_vfsopstats[op].gen_intrn++)
    
    extern const struct cdevsw vcoda_cdevsw;
    extern const struct vnodeopv_desc coda_vnodeop_opv_desc;
    
    const struct vnodeopv_desc * const coda_vnodeopv_descs[] = {
            &coda_vnodeop_opv_desc,
            NULL,
    };
    
    struct vfsops coda_vfsops = {
            .vfs_name = MOUNT_CODA,
            .vfs_min_mount_data = 256,
                           /* This is the pathname, unlike every other fs */
           .vfs_mount = coda_mount,
           .vfs_start = coda_start,
           .vfs_unmount = coda_unmount,
           .vfs_root = coda_root,
           .vfs_quotactl = (void *)eopnotsupp,
           .vfs_statvfs = coda_nb_statvfs,
           .vfs_sync = coda_sync,
           .vfs_vget = coda_vget,
           .vfs_loadvnode = coda_loadvnode,
           .vfs_fhtovp = (void *)eopnotsupp,
           .vfs_vptofh = (void *)eopnotsupp,
           .vfs_init = coda_init,
           .vfs_done = coda_done,
           .vfs_mountroot = (void *)eopnotsupp,
           .vfs_snapshot = (void *)eopnotsupp,
           .vfs_extattrctl = vfs_stdextattrctl,
           .vfs_suspendctl = genfs_suspendctl,
           .vfs_renamelock_enter = genfs_renamelock_enter,
           .vfs_renamelock_exit = genfs_renamelock_exit,
           .vfs_fsync = (void *)eopnotsupp,
           .vfs_opv_descs = coda_vnodeopv_descs
   };
   
   static int
   coda_modcmd(modcmd_t cmd, void *arg)
   {
   
           switch (cmd) {
           case MODULE_CMD_INIT:
                   return vfs_attach(&coda_vfsops);
           case MODULE_CMD_FINI:
                   return vfs_detach(&coda_vfsops);
           default:
                   return ENOTTY;
           }
   }
   
   int
   coda_vfsopstats_init(void)
   {
           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;
   }
   
   /*
    * cfs mount vfsop
    * Set up mount info record and attach it to vfs struct.
    */
   /*ARGSUSED*/
   int
   coda_mount(struct mount *vfsp,  /* Allocated and initialized by mount(2) */
       const char *path,   /* path covered: ignored by the fs-layer */
       void *data,         /* Need to define a data type for this in netbsd? */
       size_t *data_len)
   {
       struct lwp *l = curlwp;
       struct vnode *dvp;
       struct cnode *cp;
       dev_t dev;
       struct coda_mntinfo *mi;
       struct vnode *rtvp;
       const struct cdevsw *cdev;
       CodaFid rootfid = INVAL_FID;
       CodaFid ctlfid = CTL_FID;
       int error;
   
       if (data == NULL)
           return EINVAL;
       if (vfsp->mnt_flag & MNT_GETARGS)
           return EINVAL;
       ENTRY;
   
       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(). */
   
       /*
        * XXX: coda passes the mount device as the entire mount args,
        * All other fs pass a structure contining a pointer.
        * In order to get sys_mount() to do the copyin() we've set a
        * fixed default size for the filename buffer.
        */
       /* Ensure that namei() doesn't run off the filename buffer */
       if (*data_len < 1 || *data_len > PATH_MAX ||
           strnlen(data, *data_len) >= *data_len) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return EINVAL;
       }
       error = namei_simple_kernel((char *)data, NSM_FOLLOW_NOEMULROOT,
                   &dvp);
   
       if (error) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return (error);
       }
       if (dvp->v_type != VCHR) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           vrele(dvp);
           return(ENXIO);
       }
       dev = dvp->v_rdev;
       vrele(dvp);
       cdev = cdevsw_lookup(dev);
       if (cdev == NULL) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return(ENXIO);
       }
   
       /*
        * See if the device table matches our expectations.
        */
       if (cdev != &vcoda_cdevsw)
       {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return(ENXIO);
       }
   
       if (minor(dev) >= NVCODA) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return(ENXIO);
       }
   
       /*
        * Initialize the mount record and link it to the vfs struct
        */
       mi = &coda_mnttbl[minor(dev)];
   
       if (!VC_OPEN(&mi->mi_vcomm)) {
           MARK_INT_FAIL(CODA_MOUNT_STATS);
           return(ENODEV);
       }
   
       /* No initialization (here) of mi_vcomm! */
       vfsp->mnt_data = mi;
       vfsp->mnt_stat.f_fsidx.__fsid_val[0] = 0;
       vfsp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_CODA);
       vfsp->mnt_stat.f_fsid = vfsp->mnt_stat.f_fsidx.__fsid_val[0];
       vfsp->mnt_stat.f_namemax = CODA_MAXNAMLEN;
       mi->mi_vfsp = vfsp;
   
       /*
        * 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);
       rtvp = CTOV(cp);
       rtvp->v_vflag |= VV_ROOT;
   
       cp = make_coda_node(&ctlfid, vfsp, VCHR);
   
       coda_ctlvp = CTOV(cp);
   
       /* Add vfs and rootvp to chain of vfs hanging off mntinfo */
       mi->mi_vfsp = vfsp;
       mi->mi_rootvp = rtvp;
   
       /* set filesystem block size */
       vfsp->mnt_stat.f_bsize = 8192;          /* XXX -JJK */
       vfsp->mnt_stat.f_frsize = 8192;         /* XXX -JJK */
   
       /* error is currently guaranteed to be zero, but in case some
          code changes... */
       CODADEBUG(1,
                myprintf(("coda_mount returned %d\n",error)););
       if (error)
           MARK_INT_FAIL(CODA_MOUNT_STATS);
       else
           MARK_INT_SAT(CODA_MOUNT_STATS);
   
       return set_statvfs_info("/coda", UIO_SYSSPACE, "CODA", UIO_SYSSPACE,
           vfsp->mnt_op->vfs_name, vfsp, l);
   }
   
   int
   coda_start(struct mount *vfsp, int flags)
   {
       ENTRY;
       vftomi(vfsp)->mi_started = 1;
       return (0);
   }
   
   int
   coda_unmount(struct mount *vfsp, int mntflags)
   {
       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
           mi->mi_started = 0;
   
           vrele(mi->mi_rootvp);
           vrele(coda_ctlvp);
   
           active = coda_kill(vfsp, NOT_DOWNCALL);
           mi->mi_rootvp->v_vflag &= ~VV_ROOT;
           error = vflush(mi->mi_vfsp, NULLVP, FORCECLOSE);
           printf("coda_unmount: active = %d, vflush active %d\n", active, error);
           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;
           mi->mi_rootvp = 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(struct mount *vfsp, int lktype, struct vnode **vpp)
   {
       struct coda_mntinfo *mi = vftomi(vfsp);
       int error;
       struct lwp *l = curlwp;    /* XXX - bnoble */
       CodaFid VFid;
       static const CodaFid invalfid = INVAL_FID;
   
       ENTRY;
       MARK_ENTRY(CODA_ROOT_STATS);
   
       if (vfsp == mi->mi_vfsp) {
           if (memcmp(&VTOC(mi->mi_rootvp)->c_fid, &invalfid, sizeof(CodaFid)))
               { /* Found valid root. */
                   *vpp = mi->mi_rootvp;
                   /* On Mach, this is vref.  On NetBSD, VOP_LOCK */
                   vref(*vpp);
                   vn_lock(*vpp, lktype);
                   MARK_INT_SAT(CODA_ROOT_STATS);
                   return(0);
               }
       }
   
       error = venus_root(vftomi(vfsp), l->l_cred, l->l_proc, &VFid);
   
       if (!error) {
           struct cnode *cp = VTOC(mi->mi_rootvp);
   
           /*
            * Save the new rootfid in the cnode, and rekey the cnode
            * with the new fid key.
            */
           error = vcache_rekey_enter(vfsp, mi->mi_rootvp,
               &invalfid, sizeof(CodaFid), &VFid, sizeof(CodaFid));
           if (error)
                   goto exit;
           cp->c_fid = VFid;
           vcache_rekey_exit(vfsp, mi->mi_rootvp,
               &invalfid, sizeof(CodaFid), &cp->c_fid, sizeof(CodaFid));
   
           *vpp = mi->mi_rootvp;
           vref(*vpp);
           vn_lock(*vpp, lktype);
           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;
           vref(*vpp);
           vn_lock(*vpp, lktype);
           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 file system statistics.
    */
   int
   coda_nb_statvfs(struct mount *vfsp, struct statvfs *sbp)
   {
       struct lwp *l = curlwp;
       struct coda_statfs fsstat;
       int error;
   
       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
        */
       /* Note: Normal fs's have a bsize of 0x400 == 1024 */
   
       error = venus_statfs(vftomi(vfsp), l->l_cred, l, &fsstat);
   
       if (!error) {
           sbp->f_bsize = 8192; /* XXX */
           sbp->f_frsize = 8192; /* XXX */
           sbp->f_iosize = 8192; /* XXX */
           sbp->f_blocks = fsstat.f_blocks;
           sbp->f_bfree  = fsstat.f_bfree;
           sbp->f_bavail = fsstat.f_bavail;
           sbp->f_bresvd = 0;
           sbp->f_files  = fsstat.f_files;
           sbp->f_ffree  = fsstat.f_ffree;
           sbp->f_favail = fsstat.f_ffree;
           sbp->f_fresvd = 0;
           copy_statvfs_info(sbp, vfsp);
       }
   
       MARK_INT_SAT(CODA_STATFS_STATS);
       return(error);
   }
   
   /*
    * Flush any pending I/O.
    */
   int
   coda_sync(struct mount *vfsp, int waitfor,
       kauth_cred_t cred)
   {
       ENTRY;
       MARK_ENTRY(CODA_SYNC_STATS);
       MARK_INT_SAT(CODA_SYNC_STATS);
       return(0);
   }
   
   int
   coda_vget(struct mount *vfsp, ino_t ino, int lktype,
       struct vnode **vpp)
   {
       ENTRY;
       return (EOPNOTSUPP);
   }
   
   int
   coda_loadvnode(struct mount *mp, struct vnode *vp,
       const void *key, size_t key_len, const void **new_key)
   {
           CodaFid fid;
           struct cnode *cp;
           extern int (**coda_vnodeop_p)(void *);
   
           KASSERT(key_len == sizeof(CodaFid));
           memcpy(&fid, key, key_len);
   
           cp = kmem_zalloc(sizeof(*cp), KM_SLEEP);
           mutex_init(&cp->c_lock, MUTEX_DEFAULT, IPL_NONE);
           cp->c_fid = fid;
           cp->c_vnode = vp;
           vp->v_op = coda_vnodeop_p;
           vp->v_tag = VT_CODA;
           vp->v_type = VNON;
           vp->v_data = cp;
   
           *new_key = &cp->c_fid;
   
           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(struct mount *vfsp, struct fid *fhp, struct mbuf *nam,
       struct vnode **vpp, int *exflagsp,
       kauth_cred_t *creadanonp, int lktype)
   {
       struct cfid *cfid = (struct cfid *)fhp;
       struct cnode *cp = 0;
       int error;
       struct lwp *l = curlwp; /* XXX -mach */
       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, l->l_cred, l->l_proc, &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);
   }
   
   int
   coda_vptofh(struct vnode *vnp, struct fid *fidp)
   {
       ENTRY;
       return (EOPNOTSUPP);
   }
   
   void
   coda_init(void)
   {
       ENTRY;
   }
   
   void
   coda_done(void)
   {
       ENTRY;
   }
   
   SYSCTL_SETUP(sysctl_vfs_coda_setup, "sysctl vfs.coda subtree setup")
   {
   
           sysctl_createv(clog, 0, NULL, NULL,
                          CTLFLAG_PERMANENT,
                          CTLTYPE_NODE, "coda",
                          SYSCTL_DESCR("code vfs options"),
                          NULL, 0, NULL, 0,
                          CTL_VFS, 18, CTL_EOL);
           /*
            * XXX the "18" above could be dynamic, thereby eliminating
            * one more instance of the "number to vfs" mapping problem,
            * but "18" is the order as taken from sys/mount.h
            */
   
   /*
           sysctl_createv(clog, 0, NULL, NULL,
                          CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                          CTLTYPE_INT, "clusterread",
                          SYSCTL_DESCR( anyone? ),
                          NULL, 0, &doclusterread, 0,
                          CTL_VFS, 18, FFS_CLUSTERREAD, CTL_EOL);
   */
   }
   
   /*
    * 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 orphan-ness.  So this function will
    * get a new vnode for the file from the current run of Venus.
    */
   
   int
   getNewVnode(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, LK_EXCLUSIVE);
   }
   
   /* Get the mount structure corresponding to a given device.
    * Return NULL if no device is found or the device is not mounted.
    */
   struct mount *devtomp(dev_t dev)
   {
       struct mount *mp;
       struct vnode *vp;
   
       if (spec_node_lookup_by_dev(VBLK, dev, VDEAD_NOWAIT, &vp) == 0) {
           mp = spec_node_getmountedfs(vp);
           vrele(vp);
       } else {
           mp = NULL;
       }
   
       return mp;
   }

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