Commit 197f6c42 authored by Kirill Smelkov's avatar Kirill Smelkov

.

parent bb8d466b
......@@ -23,7 +23,6 @@ package main
import (
"context"
"fmt"
"sync/atomic"
"syscall"
log "github.com/golang/glog"
......@@ -185,10 +184,13 @@ type ZConn struct {
// read-only transaction under which we access zodb.Connection data.
txnCtx context.Context // XXX -> better directly store txn
// for historic @<rev> acess the connection can be shared between several bigfiles.
/* XXX redecided to purge files and @<rev>/ on atime timeout
// for historic @<rev> access the connection can be shared between several bigfiles.
// since we want to free such connections when no longer needed we
// return zodb.Connection back to zodb.DB when refcnt drops to 0.
refcnt int32
*/
}
// zopen opens new connection to ZODB database + associated read-only transaction.
......@@ -213,10 +215,11 @@ func zopen(ctx context.Context, zdb *zodb.DB, zopt *zodb.ConnOptions) (_ *ZConn,
return &ZConn{
Connection: zconn,
txnCtx: txnCtx,
refcnt: 1,
// refcnt: 1,
}, nil
}
/*
// Release decrements reference count and releases connection back to zodb.DB
// if it is no longer used.
func (zc *ZConn) Release() {
......@@ -249,8 +252,8 @@ func (zc *ZConn) Incref() {
// if the connection for this @<rev> was already opened - it is shared.
func (r *Root) zopenAt(ctx context.Context, rev zodb.Tid) (_ *ZConn, err error) {
// check if zconn for @<rev> is already there
r.zrevMu.Lock()
zconn := r.zrevTab[rev]
r.revMu.Lock()
zconn := r.revTab[rev]
if zconn != nil {
if atomic.LoadInt32(&zconn.refcnt) > 0 {
zconn.Incref()
......@@ -258,43 +261,43 @@ func (r *Root) zopenAt(ctx context.Context, rev zodb.Tid) (_ *ZConn, err error)
zconn = nil // in-progress destruction
}
}
r.zrevMu.Unlock()
r.revMu.Unlock()
if zconn != nil {
return zconn, nil
}
// not there - without zrevMu lock proceed to open it
// not there - without revMu lock proceed to open it
zconn, err = zopen(ctx, r.zdb, &zodb.ConnOptions{At: rev})
if err != nil {
return nil, err
}
// relock zrevTab and either register zconn, or returun another zconn2,
// that might have been opened while we were not holding zrevMu.
r.zrevMu.Lock()
defer r.zrevMu.Unlock()
// relock revTab and either register zconn, or returun another zconn2,
// that might have been opened while we were not holding revMu.
r.revMu.Lock()
defer r.revMu.Unlock()
zconn2 := r.zrevTab[rev]
zconn2 := r.revTab[rev]
if zconn2 != nil {
if atomic.LoadInt32(&zconn2.refcnt) > 0 {
zconn.Release()
zconn.Release() // FIXME aborts txn -> just drop zconn
zconn2.Incref()
return zconn2, nil
}
// else it was another in-progress destruction
}
r.zrevTab[rev] = zconn
r.revTab[rev] = zconn
// schedule del zrevTab[rev] on zconn destroy
// schedule del revTab[rev] on zconn destroy
txn := transaction.Current(zconn.txnCtx)
txn.RegisterSync(&zrevTabUnregister{r, zconn})
return zconn, nil
}
// zrevTabUnregister unregisters zconn from root.zrevTab on zconn's transaction abort.
// zrevTabUnregister unregisters zconn from root.revTab on zconn's transaction abort.
type zrevTabUnregister struct {
root *Root
zconn *ZConn
......@@ -304,12 +307,13 @@ func (u *zrevTabUnregister) BeforeCompletion(txn transaction.Transaction) {}
func (u *zrevTabUnregister) AfterCompletion(txn transaction.Transaction) {
rev := u.zconn.At()
u.root.zrevMu.Lock()
defer u.root.zrevMu.Unlock()
u.root.revMu.Lock()
defer u.root.revMu.Unlock()
// delete only if zconn is still registered - as another zconn2 might have
// been already registered instead while zconn was in zrevTab with refcnt=0.
if u.root.zrevTab[rev] == u.zconn {
delete(u.root.zrevTab, rev)
// been already registered instead while zconn was in revTab with refcnt=0.
if u.root.revTab[rev] == u.zconn {
delete(u.root.revTab, rev)
}
}
*/
......@@ -390,6 +390,7 @@ import (
"lab.nexedi.com/kirr/go123/xcontext"
"lab.nexedi.com/kirr/go123/xerr"
"lab.nexedi.com/kirr/neo/go/transaction"
"lab.nexedi.com/kirr/neo/go/zodb"
"lab.nexedi.com/kirr/neo/go/zodb/btree"
_ "lab.nexedi.com/kirr/neo/go/zodb/wks"
......@@ -412,24 +413,23 @@ type Root struct {
// only one connection is used for head/ and only one for each @<rev>.
zdb *zodb.DB
// ZODB connection for head/
zheadMu sync.RWMutex // protects access to zhead & live _objects_ associated with it
zhead *ZConn // zwatcher resyncs zhead; others only read zhead objects.
// directory + ZODB connection for head/
head *Head
// ZODB connections for @<rev>/
zrevMu sync.Mutex
zrevTab map[zodb.Tid]*ZConn
// XXX include?
// // {} rev -> @<rev>/
// mu sync.Mutex
// revTab map[zodb.Tid]*Rev
// directories + ZODB connections for @<rev>/
revMu sync.Mutex
revTab map[zodb.Tid]*Head
}
// /(head|<rev>)/ - served by Head. XXX separate Rev?
// /(head|<rev>)/ - served by Head.
type Head struct {
nodefs.Node
// bigfile, at, watch, etc - all implicitly linked to by fs
rev zodb.Tid // 0 for head/, !0 for @<rev>/
// bigfile/, at, watch, etc - all implicitly linked to by fs
// ZODB connection for everything under this head
zconnMu sync.RWMutex // protects access to zconn & live _objects_ associated with it
zconn *ZConn // for head/ zwatcher resyncs head.zconn; others only read zconn objects.
}
// /head/watch - served by Watch.
......@@ -442,6 +442,7 @@ type Watch struct {
// /(head|<rev>)/bigfile/ - served by BigFileDir.
type BigFileDir struct {
nodefs.Node
head *Head // parent head/ or @<rev>/
// {} oid -> <bigfileX>
mu sync.Mutex
......@@ -452,8 +453,9 @@ type BigFileDir struct {
type BigFile struct {
nodefs.Node
// this BigFile views ZODB via zconn
zconn *ZConn
// this BigFile is under head; it views ZODB via head.zconn
// parent's BigFileDir.head is the same.
head *Head
// ZBigFile top-level object. Kept activated during lifetime of current transaction.
zbf *ZBigFile
......@@ -629,9 +631,9 @@ func (f *BigFile) invalidateBlk(ctx context.Context, blk int64) error {
// ----------------------------------------
// /(head/<rev>)/bigfile/ -> Lookup receives client request to create (head|<rev>)/bigfile/<bigfileX>.
// /(head|<rev>)/bigfile/ -> Lookup receives client request to create /(head|<rev>)/bigfile/<bigfileX>.
func (bfdir *BigFileDir) Lookup(out *fuse.Attr, name string, fctx *fuse.Context) (*nodefs.Inode, fuse.Status) {
f, err := bfdir.lookup(out, name, fctx) // XXX reorder out?
f, err := bfdir.lookup(out, name, fctx)
var inode *nodefs.Inode
if f != nil {
inode = f.Inode()
......@@ -642,17 +644,21 @@ func (bfdir *BigFileDir) Lookup(out *fuse.Attr, name string, fctx *fuse.Context)
func (bfdir *BigFileDir) lookup(out *fuse.Attr, name string, fctx *fuse.Context) (f *BigFile, err error) {
defer xerr.Contextf(&err, "/bigfile: lookup %q", name)
defer func() {
if f != nil {
f.getattr(out)
}
}()
oid, err := zodb.ParseOid(name)
if err != nil {
return nil, eINVALf("not oid")
}
bfdir.head.zconnMu.Lock()
defer bfdir.head.zconnMu.Unlock()
defer func() {
if f != nil {
f.getattr(out)
}
}()
// check to see if dir(oid) is already there
bfdir.mu.Lock()
f, already := bfdir.tab[oid]
......@@ -663,7 +669,7 @@ func (bfdir *BigFileDir) lookup(out *fuse.Attr, name string, fctx *fuse.Context)
}
// not there - without bfdir lock proceed to open BigFile from ZODB
f, err = bigopen(asctx(fctx), groot.zhead, oid) // XXX zhead -> head|rev.zconn
f, err = bfdir.head.bigopen(asctx(fctx), oid)
if err != nil {
return nil, err
}
......@@ -690,6 +696,9 @@ func (bfdir *BigFileDir) lookup(out *fuse.Attr, name string, fctx *fuse.Context)
// XXX do we need to support unlink? (probably no)
// / -> Mkdir receives client request to create @<rev>/.
//
// it is not an error if @<rev>/ already exists - mkdir succeeds and EEXIST is not returned.
// in other words mkdir behaves here similarly to `mkdir -p`.
func (root *Root) Mkdir(name string, mode uint32, fctx *fuse.Context) (*nodefs.Inode, fuse.Status) {
inode, err := root.mkdir(name, fctx) // XXX ok to ignore mode?
return inode, err2LogStatus(err)
......@@ -710,51 +719,56 @@ func (root *Root) mkdir(name string, fctx *fuse.Context) (_ *nodefs.Inode, err e
}
// check to see if dir(rev) is already there
root.zrevMu.Lock()
_, already := root.zrevTab[rev]
root.zrevMu.Unlock()
root.revMu.Lock()
_, already := root.revTab[rev]
root.revMu.Unlock()
if already {
return nil, syscall.EEXIST
}
// not there - without zrevMu lock proceed to open @rev view of ZODB
// not there - without revMu lock proceed to open @rev view of ZODB
ctx := asctx(fctx)
zconnRev, err := groot.zopenAt(ctx, rev)
// zconnRev, err := root.zopenAt(ctx, rev)
zconnRev, err := zopen(ctx, root.zdb, &zodb.ConnOptions{At: rev})
if err != nil {
return nil, err
}
defer zconnRev.Release() // XXX ok?
// relock root and either mkdir or EEXIST if the directory was maybe
// simultanously created while we were not holding zrevMu.
root.zrevMu.Lock()
_, already = root.zrevTab[rev]
// simultanously created while we were not holding revMu.
root.revMu.Lock()
_, already = root.revTab[rev]
if already {
root.zrevMu.Unlock()
root.revMu.Unlock()
// zconnRev.Release()
transaction.Current(zconnRev.txnCtx).Abort()
return nil, syscall.EEXIST
}
revDir := &Head{ // XXX -> Rev ?
revDir := &Head{
Node: nodefs.NewDefaultNode(),
rev: rev,
zconn: zconnRev,
}
root.zrevTab[rev] = zconnRev
root.zrevMu.Unlock()
root.revTab[rev] = revDir
root.revMu.Unlock()
// mkdir takes filesystem treeLock - do it outside zrevMu.
// mkdir takes filesystem treeLock - do it outside revMu.
mkdir(root, name, revDir)
return revDir.Inode(), nil
}
// bigopen opens BigFile corresponding to oid on zconn.
// bigopen opens BigFile corresponding to oid on head.zconn.
//
// A ZBigFile corresponding to oid is activated and statted.
//
// The whole result is returned as BigFile.
func bigopen(ctx context.Context, zconn *ZConn, oid zodb.Oid) (_ *BigFile, err error) {
// head.zconn must be locked.
func (head *Head) bigopen(ctx context.Context, oid zodb.Oid) (_ *BigFile, err error) {
zconn := head.zconn
defer xerr.Contextf(&err, "bigopen %s @%s", oid, zconn.At())
// XXX better ctx = transaction.PutIntoContext(ctx, txn)
......@@ -794,10 +808,10 @@ func bigopen(ctx context.Context, zconn *ZConn, oid zodb.Oid) (_ *BigFile, err e
return nil, err
}
zconn.Incref()
// zconn.Incref()
return &BigFile{
Node: nodefs.NewDefaultNode(),
zconn: zconn,
head: head,
zbf: zbf,
zbfSize: zbfSize,
......@@ -809,11 +823,12 @@ func bigopen(ctx context.Context, zconn *ZConn, oid zodb.Oid) (_ *BigFile, err e
// Close release all resources of BigFile.
func (f *BigFile) Close() error {
f.zbf.PDeactivate()
f.zbf.PDeactivate() // XXX f.head.zconn must locked
f.zbf = nil
f.zconn.Release()
f.zconn = nil
// f.zconn.Release()
// f.zconn = nil
f.head = nil
return nil
}
......@@ -842,7 +857,8 @@ func (f *BigFile) getattr(out *fuse.Attr) {
// /(head|<rev>)/bigfile/<bigfileX> -> Read serves reading bigfile data.
func (f *BigFile) Read(_ nodefs.File, dest []byte, off int64, fctx *fuse.Context) (fuse.ReadResult, fuse.Status) {
// XXX locking
f.head.zconnMu.RLock()
defer f.head.zconnMu.RUnlock()
zbf := f.zbf
......@@ -866,7 +882,7 @@ func (f *BigFile) Read(_ nodefs.File, dest []byte, off int64, fctx *fuse.Context
dest = make([]byte, aend - aoff) // ~> [aoff:aend) in file
// XXX better ctx = transaction.PutIntoContext(ctx, txn)
ctx, cancel := xcontext.Merge(asctx(fctx), f.zconn.txnCtx)
ctx, cancel := xcontext.Merge(asctx(fctx), f.head.zconn.txnCtx)
defer cancel()
// read/load all block(s) in parallel
......@@ -1014,11 +1030,9 @@ func (f *BigFile) readBlk(ctx context.Context, blk int64, dest []byte) error {
// /(head|<rev>)/at -> readAt serves read.
func (h *Head) readAt() []byte {
// XXX implemented only for Head, not Rev
root := groot
root.zheadMu.Lock()
defer root.zheadMu.Unlock()
return []byte(root.zhead.At().String())
h.zconnMu.Lock()
defer h.zconnMu.Unlock()
return []byte(h.zconn.At().String())
}
......@@ -1031,7 +1045,7 @@ func (h *Head) readAt() []byte {
// - Mount:
// .Root() -> root Inode of the fs
// .Connector() -> FileSystemConnector through which fs is mounted
var groot *Root
//var groot *Root
var gfsconn *nodefs.FileSystemConnector
func main() {
......@@ -1070,13 +1084,19 @@ func main() {
}
zhead.Cache().SetControl(&zodbCacheControl{}) // XXX +locking?
// mount root
// mount root + head/
head := &Head{
Node: nodefs.NewDefaultNode(),
rev: 0,
zconn: zhead,
}
root := &Root{
Node: nodefs.NewDefaultNode(),
zstor: zstor,
zdb: zdb,
zhead: zhead,
zrevTab: make(map[zodb.Tid]*ZConn),
head: head,
revTab: make(map[zodb.Tid]*Head),
}
opts := &fuse.MountOptions{
......@@ -1091,7 +1111,7 @@ func main() {
if err != nil {
log.Fatal(err)
}
groot = root // FIXME temp workaround (see ^^^)
//groot = root // FIXME temp workaround (see ^^^)
gfsconn = fsconn // FIXME ----//----
// we require proper pagecache control (added to Linux 2.6.36 in 2010)
......@@ -1102,12 +1122,10 @@ func main() {
// add entries to /
mkfile(root, ".wcfs", NewStaticFile([]byte(zurl)))
head := &Head{
Node: nodefs.NewDefaultNode(),
}
mkdir(root, "head", head)
mkdir(head, "bigfile", &BigFileDir{
Node: nodefs.NewDefaultNode(),
head: head,
tab: make(map[zodb.Oid]*BigFile),
})
mkfile(head, "at", NewSmallFile(head.readAt)) // TODO mtime(at) = tidtime(at)
......
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