20060303a

1 files changed, 147 insertions, 0 deletions

diff --git a/liblogfs/remove.c b/liblogfs/remove.c
new file mode 100644
index 00000000..acc85dd2
--- /dev/null
+++ b/liblogfs/remove.c
@@ -0,0 +1,147 @@
+#include "lib9.h"
+#include "logfs.h"
+#include "local.h"
+
+void
+logfsfreeanddirtydatablockcheck(LogfsServer *server, long seq)
+{
+	DataBlock *db;
+	u32int mask;
+
+	if(seq >= server->ndatablocks)
+		return;
+	db = server->datablock + seq;
+	if(db->block < 0)
+		return;
+
+	mask = db->dirty & db->free;
+	if(mask) {
+		u32int allpages = logfsdatapagemask(1 << server->ll->l2pagesperblock, 0);
+		if((mask & allpages) == allpages) {
+//print("logfsfreedatapages: returning block to the wild\n");
+			logfsbootfettleblock(server->lb, db->block, LogfsTnone, ~0, nil);
+			db->block = -1;
+			if(seq == server->ndatablocks - 1)
+				server->ndatablocks--;
+		}
+	}
+}
+
+void
+logfsfreedatapages(LogfsServer *server, long seq, u32int mask)
+{
+	DataBlock *db;
+	if(seq >= server->ndatablocks)
+		return;
+	db = server->datablock + seq;
+	if(db->block < 0)
+		return;
+//print("logfsfreedatapages: index %ld mask 0x%.8ux\n", seq, mask);
+	db->dirty |= mask;
+	db->free |= mask;
+	logfsfreeanddirtydatablockcheck(server, seq);
+}
+
+int
+logfsunconditionallymarkfreeanddirty(void *magic, Extent *e, int hole)
+{
+	if(!hole && (e->flashaddr & LogAddr) == 0) {
+		LogfsServer *server = magic;
+		LogfsLowLevel *ll = server->ll;
+		DataBlock *db;
+		long blockindex;
+		int page, offset;
+		logfsflashaddr2spo(server, e->flashaddr, &blockindex, &page, &offset);
+		if(blockindex < server->ndatablocks && (db = server->datablock + blockindex)->block >= 0) {
+			int npages = ((offset + e->max - e->min) + (1 << ll->l2pagesize) - 1) >> ll->l2pagesize;
+			u32int mask = logfsdatapagemask(npages, page);
+			if((db->dirty & mask) != mask)
+				print("markfreeandirty: not all pages dirty\n");
+//print("markfreeanddirty: datablock %ld mask 0x%.8ux\n", blockindex, mask);
+			logfsfreedatapages(server, blockindex, mask);
+		}
+		else
+			print("markfreeanddirty: data block index %ld invalid\n", blockindex);
+	}
+	return 1;
+}
+
+char *
+logfsserverremove(LogfsServer *server, u32int fid)
+{
+	Fid *f;
+	char *errmsg;
+	Entry *parent;
+	Entry *e, **ep;
+	ulong now;
+	char *uid;
+	LogMessage s;
+
+	if(server->trace > 1)
+		print("logfsserverremove(%ud)\n", fid);
+	f = logfsfidmapfindentry(server->fidmap, fid);
+	if(f == nil) {
+		errmsg = logfsebadfid;
+		goto clunk;
+	}
+	if((f->openmode & 3) == OWRITE) {
+		errmsg = logfseaccess;
+		goto clunk;
+	}
+	parent = f->entry->parent;
+	if(parent == f->entry) {
+		errmsg = Eperm;
+		goto clunk;
+	}
+	if((parent->qid.type & QTDIR) == 0) {
+		errmsg = logfseinternal;
+		goto clunk;
+	}
+	if(!logfsuserpermcheck(server, parent, f, DMWRITE)) {
+		errmsg = Eperm;
+		goto clunk;
+	}
+	if((f->entry->qid.type & QTDIR) != 0 && f->entry->u.dir.list) {
+		errmsg = logfsenotempty;
+		goto clunk;
+	}
+	if(f->entry->deadandgone) {
+		errmsg = Eio;
+		goto clunk;
+	}
+	for(ep = &parent->u.dir.list; e = *ep; ep = &e->next)
+		if(e == f->entry)
+			break;
+	if(e == nil) {
+		errmsg = logfseinternal;
+		goto clunk;
+	}
+	now = logfsnow();
+	uid = logfsisfindidfromname(server->is, f->uname);
+	/* log it */
+	s.type = LogfsLogTremove;
+	s.path = e->qid.path;
+	s.u.remove.mtime = e->mtime;
+	s.u.remove.muid = e->muid;
+	errmsg = logfslog(server, 1, &s);
+	if(errmsg)
+		goto clunk;
+	parent->mtime = now;
+	parent->muid = uid;
+	logfspathmapdeleteentry(server->pathmap, e->qid.path);
+	*ep = e->next;				/* so open can't find it */
+	e->deadandgone = 1;		/* so that other fids don't work any more */
+	/*
+	 * lose the storage now, as deadandgone will prevent access
+	 */
+	if((e->qid.type & QTDIR) == 0) {
+		logfsextentlistwalk(e->u.file.extent, logfsunconditionallymarkfreeanddirty, server);
+		logfsextentlistfree(&e->u.file.extent);
+	}
+	e->inuse--;				/* so that the entryclunk removes the storage */
+	errmsg = nil;
+clunk:
+	logfsfidmapclunk(server->fidmap, fid);
+	return errmsg;
+}
+