/* Copyright (C) 1995, 1989, 1998 Transarc Corporation - All rights reserved */
/*
 * For copyright information, see IPL which you accepted in order to
 * download this software.
 *
 */

/*
 * afs_vnop_rename.c
 *
 * Implements:
 * afsrename
 * afs_rename
 *
 */

#include "../afs/param.h"	/* Should be always first */
#include "../afs/sysincludes.h"	/* Standard vendor system headers */
#include "../afs/afsincludes.h"	/* Afs-based standard headers */
#include "../afs/afs_stats.h" /* statistics */
#include "../afs/afs_cbqueue.h"
#include "../afs/nfsclient.h"
#include "../afs/afs_osidnlc.h"

extern afs_rwlock_t afs_xcbhash;

/* Note that we don't set CDirty here, this is OK because the rename
 * RPC is called synchronously. */

afsrename(aodp, aname1, andp, aname2, acred)
    register struct vcache *aodp, *andp;
    char *aname1, *aname2;
    struct AFS_UCRED *acred; {
    struct vrequest treq;
    register struct conn *tc;
    register afs_int32 code;
    afs_int32 returnCode;
    int oneDir, doLocally;
    afs_int32 offset, len;
    struct VenusFid unlinkFid, fileFid;
    struct vcache *tvc;
    struct dcache *tdc1, *tdc2;
    struct AFSFetchStatus OutOldDirStatus, OutNewDirStatus;
    struct AFSVolSync tsync;
    XSTATS_DECLS

    AFS_STATCNT(afs_rename);
    afs_Trace4(afs_iclSetp, CM_TRACE_RENAME, ICL_TYPE_POINTER, aodp, 
	       ICL_TYPE_STRING, aname1, ICL_TYPE_POINTER, andp,
	       ICL_TYPE_STRING, aname2);

    if (code = afs_InitReq(&treq, acred)) return code;

    /* verify the latest versions of the stat cache entries */
tagain:
    code = afs_VerifyVCache(aodp, &treq);
    if (code) goto done;
    code = afs_VerifyVCache(andp, &treq);
    if (code) goto done;
    
    /* lock in appropriate order, after some checks */
    if (aodp->fid.Cell != andp->fid.Cell || aodp->fid.Fid.Volume != andp->fid.Fid.Volume) {
	code = EXDEV;
	goto done;
    }
    oneDir = 0;
    if (andp->fid.Fid.Vnode == aodp->fid.Fid.Vnode) {
	if (!strcmp(aname1, aname2)) {
	    /* Same directory and same name; this is a noop and just return success
	     * to save cycles and follow posix standards */

	    code = 0;
	    goto done;
	}
	ObtainWriteLock(&andp->lock,147);
	oneDir = 1;	    /* only one dude locked */
    }
    else if ((andp->states & CRO) || (aodp->states & CRO)) {
       code = EROFS;
       goto done;
     }
    else if (andp->fid.Fid.Vnode < aodp->fid.Fid.Vnode) {
	ObtainWriteLock(&andp->lock,148);	/* lock smaller one first */
	ObtainWriteLock(&aodp->lock,149);
    }
    else {
	ObtainWriteLock(&aodp->lock,150);	/* lock smaller one first */
	ObtainWriteLock(&andp->lock,557);
    }

    osi_dnlc_remove (aodp, aname1, 0);
    osi_dnlc_remove (andp, aname2, 0);
    afs_symhint_inval(aodp); 
    afs_symhint_inval(andp);

    /* before doing the rename, lookup the fileFid, just in case we
     * don't make it down the path below that looks it up.  We always need
     * fileFid in order to handle ".." invalidation at the very end.
     */
    code = 0;
    tdc1 = afs_GetDCache(aodp, 0, &treq, &offset, &len, 0);
    if (!tdc1) {
	code = ENOENT;
    }
    /*
     * Make sure that the data in the cache is current. We may have
     * received a callback while we were waiting for the write lock.
     */
    else if (!(aodp->states & CStatd)
	|| !hsame(aodp->m.DataVersion, tdc1->f.versionNo)) {
	ReleaseWriteLock(&aodp->lock);
	if (!oneDir) ReleaseWriteLock(&andp->lock);
	afs_PutDCache(tdc1);
	goto tagain;
    }

    if (code == 0)
	code = afs_dir_Lookup(&tdc1->f.inode, aname1, &fileFid.Fid);
    if (code) {
	if (tdc1) afs_PutDCache(tdc1);
	ReleaseWriteLock(&aodp->lock);
	if (!oneDir) ReleaseWriteLock(&andp->lock);
	goto done;
    }
    afs_PutDCache(tdc1);

    /* locks are now set, proceed to do the real work */
    do {
	tc = afs_Conn(&aodp->fid, &treq, SHARED_LOCK);
	if (tc) {
          XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_RENAME);
#ifdef RX_ENABLE_LOCKS
	  AFS_GUNLOCK();
#endif /* RX_ENABLE_LOCKS */
	  code = RXAFS_Rename(tc->id, (struct AFSFid *) &aodp->fid.Fid, aname1,
				(struct AFSFid *) &andp->fid.Fid, aname2,
				&OutOldDirStatus, &OutNewDirStatus, &tsync);
#ifdef RX_ENABLE_LOCKS
	  AFS_GLOCK();
#endif /* RX_ENABLE_LOCKS */
          XSTATS_END_TIME;
	} else code = -1;

    } while
	(afs_Analyze(tc, code, &andp->fid, &treq,
		     AFS_STATS_FS_RPCIDX_RENAME, SHARED_LOCK, (struct cell *)0));

    returnCode = code;	    /* remember for later */
    
    /* Now we try to do things locally.  This is really loathsome code. */
    unlinkFid.Fid.Vnode = 0;
    if (code == 0) {
	tdc1 = tdc2 = 0;
	/* don't use GetDCache because we don't want to worry about what happens if
	    we have to stat the file (updating the stat block) before finishing
	    local hero stuff (which may put old (from rename) data version number
	    back in the cache entry).
	    In any event, we don't really care if the data is not
	    in the cache; if it isn't, we won't do the update locally.  */
	tdc1 = afs_FindDCache(aodp, 0);
	if (!oneDir) tdc2 = afs_FindDCache(andp, 0);
	else tdc2 = tdc1;
	/* see if version numbers increased properly */
	doLocally = 1;
	if (oneDir) {
	    /* number increases by 1 for whole rename operation */
	    if (!afs_LocalHero(aodp, tdc1, &OutOldDirStatus, 1)) {
		doLocally = 0;
	    }
	}
	else {
	    /* two separate dirs, each increasing by 1 */
	    if (!afs_LocalHero(aodp, tdc1, &OutOldDirStatus, 1))
		doLocally = 0;
	    if (!afs_LocalHero(andp, tdc2, &OutNewDirStatus, 1))
		doLocally = 0;
	    if (!doLocally) {
		if (tdc1) {
		    ZapDCE(tdc1);
		    DZap(&tdc1->f.inode);
		}
		if (tdc2) {
		    ZapDCE(tdc2);
		    DZap(&tdc2->f.inode);
		}
	    }
	}
	/* now really do the work */
	if (doLocally) {
	    /* first lookup the fid of the dude we're moving */
	    code = afs_dir_Lookup(&tdc1->f.inode, aname1, &fileFid.Fid);
	    if (code == 0) {
		/* delete the source */
		code = afs_dir_Delete(&tdc1->f.inode, aname1);
	    }
	    /* first see if target is there */
	    if (code == 0 &&
		afs_dir_Lookup(&tdc2->f.inode, aname2, &unlinkFid.Fid) == 0) {
		/* target already exists, and will be unlinked by server */
		code = afs_dir_Delete(&tdc2->f.inode, aname2);
	    }
	    if (code == 0) {
		code = afs_dir_Create(&tdc2->f.inode, aname2, &fileFid.Fid);
	    }
	    if (code != 0) {
		ZapDCE(tdc1);
		DZap(&tdc1->f.inode);
		if (!oneDir) {
		    ZapDCE(tdc2);
		    DZap(&tdc2->f.inode);
		}
	    }
	}
	if (tdc1) afs_PutDCache(tdc1);
	if ((!oneDir) && tdc2) afs_PutDCache(tdc2);

	/* update dir link counts */
	aodp->m.LinkCount = OutOldDirStatus.LinkCount;
	if (!oneDir)
	    andp->m.LinkCount = OutNewDirStatus.LinkCount;

    }
    else {	/* operation failed (code != 0) */
	if (code < 0) {	
	    /* if failed, server might have done something anyway, and 
	     * assume that we know about it */
	  ObtainWriteLock(&afs_xcbhash, 498);
	  afs_DequeueCallback(aodp);
	  afs_DequeueCallback(andp);
	  andp->states &= ~CStatd;
	  aodp->states &= ~CStatd;
	  ReleaseWriteLock(&afs_xcbhash);
	  osi_dnlc_purgedp(andp);
	  osi_dnlc_purgedp(aodp);
	}
    }

    /* release locks */
    ReleaseWriteLock(&aodp->lock);
    if (!oneDir) ReleaseWriteLock(&andp->lock);
    
    if (returnCode) {
	code = returnCode;
	goto done;
    }

    /* now, some more details.  if unlinkFid.Fid.Vnode then we should decrement
	the link count on this file.  Note that if fileFid is a dir, then we don't
	have to invalidate its ".." entry, since its DataVersion # should have
	changed. However, interface is not good enough to tell us the
	*file*'s new DataVersion, so we're stuck.  Our hack: delete mark
	the data as having an "unknown" version (effectively discarding the ".."
	entry */
    if (unlinkFid.Fid.Vnode) {
	unlinkFid.Fid.Volume = aodp->fid.Fid.Volume;
	unlinkFid.Cell = aodp->fid.Cell;
	tvc = (struct vcache *)0;
	if (!unlinkFid.Fid.Unique) {
	    tvc = afs_LookupVCache(&unlinkFid, &treq, (afs_int32 *)0, WRITE_LOCK,
				   aodp, aname1);
	}
	if (!tvc) /* lookup failed or wasn't called */
	   tvc = afs_GetVCache(&unlinkFid, &treq, (afs_int32 *)0,
			       (struct vcache*)0, WRITE_LOCK);

	if (tvc) {
#if	defined(AFS_SUN_ENV) || defined(AFS_ALPHA_ENV) || defined(AFS_SUN5_ENV)
	    afs_BozonLock(&tvc->pvnLock, tvc);	/* Since afs_TryToSmush will do a pvn_vptrunc */
#endif
	    ObtainWriteLock(&tvc->lock,151);
	    tvc->m.LinkCount--;
	    tvc->states &= ~CUnique;		/* For the dfs xlator */
	    if (tvc->m.LinkCount == 0 && !osi_Active(tvc)) {
		/* if this was last guy (probably) discard from cache.
                 * We have to be careful to not get rid of the stat
                 * information, since otherwise operations will start
                 * failing even if the file was still open (or
                 * otherwise active), and the server no longer has the
                 * info.  If the file still has valid links, we'll get
                 * a break-callback msg from the server, so it doesn't
                 * matter that we don't discard the status info */
		if (!AFS_NFSXLATORREQ(acred)) afs_TryToSmush(tvc, acred, 0);
	    }
	    ReleaseWriteLock(&tvc->lock);
#if	defined(AFS_SUN_ENV) || defined(AFS_ALPHA_ENV)  || defined(AFS_SUN5_ENV)
	    afs_BozonUnlock(&tvc->pvnLock, tvc);
#endif
	    afs_PutVCache(tvc, WRITE_LOCK);
	}
    }

    /* now handle ".." invalidation */
    if (!oneDir) {
	fileFid.Fid.Volume = aodp->fid.Fid.Volume;
	fileFid.Cell = aodp->fid.Cell;
	if (!fileFid.Fid.Unique)
	    tvc = afs_LookupVCache(&fileFid, &treq, (afs_int32 *)0, WRITE_LOCK, andp, aname2);
	else
	    tvc = afs_GetVCache(&fileFid, &treq, (afs_int32 *)0,
				(struct vcache*)0, WRITE_LOCK);
	if (tvc && (vType(tvc) == VDIR)) {
	    ObtainWriteLock(&tvc->lock,152);
	    tdc1 = afs_FindDCache(tvc, 0);
	    if (tdc1) {
		ZapDCE(tdc1);	/* mark as unknown */
		DZap(&tdc1->f.inode);
		afs_PutDCache(tdc1);	/* put it back */
	    }
	    osi_dnlc_remove(tvc, "..", 0);
	    ReleaseWriteLock(&tvc->lock);
	    afs_PutVCache(tvc, WRITE_LOCK);
	} else if (tvc) {
	    /* True we shouldn't come here since tvc SHOULD be a dir, but we
	     * 'syntactically' need to unless  we change the 'if' above...
	     */
	    afs_PutVCache(tvc, WRITE_LOCK);
	}
    }
    code = returnCode;
done:
    code = afs_CheckCode(code, &treq, 25);
    return code;
}

#ifdef	AFS_OSF_ENV
afs_rename(fndp, tndp)
    struct nameidata *fndp, *tndp; {
    register struct vcache *aodp = (struct vcache *)fndp->ni_dvp;
    char *aname1 = fndp->ni_dent.d_name;
    register struct vcache *andp = (struct vcache *)tndp->ni_dvp;
    char *aname2 = tndp->ni_dent.d_name;
    struct ucred *acred = tndp->ni_cred;
#else	/* AFS_OSF_ENV */
#if defined(AFS_SGI_ENV)
afs_rename(OSI_VC_ARG(aodp), aname1, andp, aname2, npnp, acred)
    struct pathname *npnp;
#else
afs_rename(OSI_VC_ARG(aodp), aname1, andp, aname2, acred)
#endif
    OSI_VC_DECL(aodp);
    register struct vcache *andp;
    char *aname1, *aname2;
    struct AFS_UCRED *acred; {
#endif
    register afs_int32 code;
    OSI_VC_CONVERT(aodp)

    code = afsrename(aodp, aname1, andp, aname2, acred);
#ifdef	AFS_OSF_ENV
    AFS_RELE(tndp->ni_dvp);
    if (tndp->ni_vp != NULL) {
	AFS_RELE(tndp->ni_vp);
    }
    AFS_RELE(fndp->ni_dvp);
    AFS_RELE(fndp->ni_vp);
#endif	/* AFS_OSF_ENV */
    return code;
}