diff options
| -rw-r--r-- | man/man1/venti.1 | 39 | ||||
| -rw-r--r-- | src/cmd/venti/copy.c | 121 |
2 files changed, 146 insertions, 14 deletions
diff --git a/man/man1/venti.1 b/man/man1/venti.1 index 12d664f4..cf160091 100644 --- a/man/man1/venti.1 +++ b/man/man1/venti.1 @@ -28,7 +28,7 @@ read, write, copy \- simple Venti clients .br .B venti/copy [ -.B -fir +.B -fimrVv ] [ .B -t @@ -99,14 +99,35 @@ the root block from the server to the server .IR dsthost . .PP +Venti's blocks are arranged in a directed acyclic graph (see venti(6)); +there may be multiple paths from a root score to an +interior block (for example, if the same file contents are stored +under multiple names in an archive). +.I Copy +runs more efficiently if it does not copy blocks +(and all their children) multiple times. The .B -f option causes .I copy -to run in `fast' mode, -assuming that if a block already exists on the -destination Venti server, all its children also -exist and need not be checked. +to assume that if a block already exists on the destination +Venti server, all its children also exist and need not be considered. +The +.B -m +option causes +.I copy +to maintain an in-memory list of blocks it has copied +and avoid considering the same block multiple times. +The +.B -f +option is only useful if the destination Venti server is +known not to have lost any blocks due to disk corruption +or other failures. +The +.B -m +option is only useful if enough memory is available to +hold the block list, which typically requires about 1% +of the total number of bytes being copied. .PP The .B -i @@ -135,6 +156,14 @@ option is given, replaces pointers to unreadable blocks with pointers to the zero block. It writes the new root score to standard output. +The +.B -v +option prints scores as it copies them, total writes, and other +debugging information. +The +.B -V +option prints debugging information about the Venti protocol +messages send/received. .SH SOURCE .B \*9/src/cmd/venti .SH SEE ALSO diff --git a/src/cmd/venti/copy.c b/src/cmd/venti/copy.c index 4a05e053..87075e48 100644 --- a/src/cmd/venti/copy.c +++ b/src/cmd/venti/copy.c @@ -3,6 +3,8 @@ #include <venti.h> #include <libsec.h> #include <thread.h> +#include <avl.h> +#include <bin.h> enum { @@ -15,25 +17,93 @@ int rewrite; int ignoreerrors; int fast; int verbose; +int nskip; +int nwrite; + VtConn *zsrc, *zdst; +uchar zeroscore[VtScoreSize]; /* all zeros */ + +typedef struct ScoreTree ScoreTree; +struct ScoreTree +{ + Avl avl; + uchar score[VtScoreSize]; + int type; +}; + +Avltree *scoretree; +Bin *scorebin; + +static int +scoretreecmp(Avl *va, Avl *vb) +{ + ScoreTree *a, *b; + int i; + + a = (ScoreTree*)va; + b = (ScoreTree*)vb; + + i = memcmp(a->score, b->score, VtScoreSize); + if(i != 0) + return i; + return a->type - b->type; +} + +static int +havevisited(uchar score[VtScoreSize], int type) +{ + ScoreTree a; + + if(scoretree == nil) + return 0; + memmove(a.score, score, VtScoreSize); + a.type = type; + return lookupavl(scoretree, &a.avl) != nil; +} + +static void +markvisited(uchar score[VtScoreSize], int type) +{ + ScoreTree *a; + Avl *old; + + if(scoretree == nil) + return; + a = binalloc(&scorebin, sizeof *a, 1); + memmove(a->score, score, VtScoreSize); + a->type = type; + insertavl(scoretree, &a->avl, &old); +} void usage(void) { - fprint(2, "usage: copy [-fir] [-t type] srchost dsthost score\n"); + fprint(2, "usage: copy [-fimrVv] [-t type] srchost dsthost score\n"); threadexitsall("usage"); } void -walk(uchar score[VtScoreSize], uint type, int base) +walk(uchar score[VtScoreSize], uint type, int base, int depth) { int i, n; uchar *buf; + uchar nscore[VtScoreSize]; VtEntry e; VtRoot root; - if(memcmp(score, vtzeroscore, VtScoreSize) == 0) + if(verbose){ + for(i = 0; i < depth; i++) + fprint(2, " "); + fprint(2, "-> %d %d %d %V\n", depth, type, base, score); + } + + if(memcmp(score, vtzeroscore, VtScoreSize) == 0 || memcmp(score, zeroscore, VtScoreSize) == 0) + return; + + if(havevisited(score, type)){ + nskip++; return; + } buf = vtmallocz(VtMaxLumpSize); if(fast && vtread(zdst, score, type, buf, VtMaxLumpSize) >= 0){ @@ -59,8 +129,8 @@ walk(uchar score[VtScoreSize], uint type, int base) fprint(2, "warning: could not unpack root in %V %d\n", score, type); break; } - walk(root.score, VtDirType, 0); - walk(root.prev, VtRootType, 0); + walk(root.prev, VtRootType, 0, depth+1); + walk(root.score, VtDirType, 0, depth+1); if(rewrite) vtrootpack(&root, buf); /* walk might have changed score */ break; @@ -73,7 +143,14 @@ walk(uchar score[VtScoreSize], uint type, int base) } if(!(e.flags & VtEntryActive)) continue; - walk(e.score, e.type, e.type&VtTypeBaseMask); + walk(e.score, e.type, e.type&VtTypeBaseMask, depth+1); + /* + * Don't repack unless we're rewriting -- some old + * vac files have psize==0 and dsize==0, and these + * get rewritten by vtentryunpack to have less strange + * block sizes. So vtentryunpack; vtentrypack does not + * guarantee to preserve the exact bytes in buf. + */ if(rewrite) vtentrypack(&e, buf, i); } @@ -85,17 +162,31 @@ walk(uchar score[VtScoreSize], uint type, int base) default: /* pointers */ for(i=0; i<n; i+=VtScoreSize) if(memcmp(buf+i, vtzeroscore, VtScoreSize) != 0) - walk(buf+i, type-1, base); + walk(buf+i, type-1, base, depth+1); break; } - if(vtwrite(zdst, score, type, buf, n) < 0){ + nwrite++; + if(vtwrite(zdst, nscore, type, buf, n) < 0){ /* figure out score for better error message */ /* can't use input argument - might have changed contents */ n = vtzerotruncate(type, buf, n); sha1(buf, n, score, nil); sysfatal("writing block %V (type %d): %r", score, type); } + if(!rewrite && memcmp(score, nscore, VtScoreSize) != 0) + sysfatal("not rewriting: wrote %V got %V", score, nscore); + + if((type !=0 || base !=0) && verbose){ + n = vtzerotruncate(type, buf, n); + sha1(buf, n, score, nil); + + for(i = 0; i < depth; i++) + fprint(2, " "); + fprint(2, "<- %V\n", score); + } + + markvisited(score, type); free(buf); } @@ -112,6 +203,9 @@ threadmain(int argc, char *argv[]) type = -1; ARGBEGIN{ + case 'V': + chattyventi++; + break; case 'f': fast = 1; break; @@ -120,6 +214,9 @@ threadmain(int argc, char *argv[]) usage(); ignoreerrors = 1; break; + case 'm': + scoretree = mkavltree(scoretreecmp); + break; case 'r': if(ignoreerrors) usage(); @@ -128,6 +225,9 @@ threadmain(int argc, char *argv[]) case 't': type = atoi(EARGF(usage())); break; + case 'v': + verbose = 1; + break; default: usage(); break; @@ -167,10 +267,13 @@ threadmain(int argc, char *argv[]) sysfatal("could not find block %V of any type", score); } - walk(score, type, VtDirType); + walk(score, type, VtDirType, 0); if(changes) print("%s:%V (%d pointers rewritten)\n", prefix, score, changes); + if(verbose) + print("%d skipped, %d written\n", nskip, nwrite); + if(vtsync(zdst) < 0) sysfatal("could not sync dst server: %r"); |