ref: 7754c42469ca6f6dff350f2d87e0903a5ce61c00
parent: 236a5fcadfeb27c1ffa2037db91486019f226d4f
author: 9ferno <gophone2015@gmail.com>
date: Sat Oct 15 02:39:47 EDT 2022
replaced Iobuf.flags with Iobuf.readonly makes the code more comprehensible Also, not reading from the disk for allocations of free blocks
--- a/9p.c
+++ b/9p.c
@@ -158,7 +158,7 @@
/* TODO cwfs/9p2.c, hjfs/fs2.c and kfs64.b do more here. Get that stuff in. */
- dbuf = getbufchk(((Aux*)req->fid->aux)->dblkno, 1, Bmod,
+ dbuf = getbufchk(((Aux*)req->fid->aux)->dblkno, 1, Bwritable,
Tdentry, req->fid->qid.path);
if(dbuf == nil){respond(req, errstring[Eperm]);
@@ -503,7 +503,7 @@
cbuf = nil;
USED(cbuf);
zblkno = 0;
- dbuf = getbufchk(aux->dblkno, 1, Bmod, Tdentry, fid->qid.path);
+ dbuf = getbufchk(aux->dblkno, 1, Bwritable, Tdentry, fid->qid.path);
if(dbuf == nil){respond(req, errstring[Ephase]);
return;
@@ -546,7 +546,7 @@
if(blkno == 0){/* end reached, nothing found, create */
if(zblkno != 0){- cbuf = getbufchk(zblkno, 1,Bmod, Tdentry, Qpnone);
+ cbuf = getbufchk(zblkno, 1,Bwritable, Tdentry, Qpnone);
if(cbuf == nil){putbuf(dbuf);
respond(req, errstring[Ephase]);
@@ -553,7 +553,7 @@
return;
}
}else{- cbuf = allocblocks(1, Bmod, Tdentry, fid->qid.path);
+ cbuf = allocblocks(1, Tdentry, fid->qid.path);
if(cbuf == nil){putbuf(dbuf);
respond(req, errstring[Efull]);
@@ -622,7 +622,7 @@
respond(req, nil);
return;
}else{- cbuf = getbuf(blkno, 1,Breadonly);
+ cbuf = getbuf(blkno, 1,Breadonly, Bused);
if(cbuf == nil){putbuf(dbuf);
respond(req, errstring[Ephase]);
@@ -1203,7 +1203,7 @@
if(d == nil || wbuf == nil || wbufsize == 0)
return 0;
- buf = getdataspanat(d, offset/Maxspansize, Bmod);
+ buf = getdataspanat(d, offset/Maxspansize, Bwritable);
if(buf == nil)
return -1;
n = min(Maxspansize, wbufsize);
@@ -1239,7 +1239,7 @@
d->name, d->size, offset, offset/Maxspansize, s.blkno, s.len);
blkno = s.blkno;
nblocks = s.len;
- buf = getbufchk(blkno, nblocks, Bmod, Tdata, d->qid.path);
+ buf = getbufchk(blkno, nblocks, Bwritable, Tdata, d->qid.path);
if(buf == nil)
return -1;
@@ -1274,7 +1274,7 @@
if((wbufsize+sizeof(Tag))%Rawblocksize > 0)
nblocks++;
- buf = allocblocks(nblocks, Bmod, Tdata, d->qid.path);
+ buf = allocblocks(nblocks, Tdata, d->qid.path);
if(buf == nil)
return -1;
blkno = buf->blkno;
@@ -1307,7 +1307,7 @@
dprint("append update rel2abs d->name %s reli d->size %llud"" d->size/Maxspansize %llud s.blkno %llud s.len %d\n",
d->name, d->size, d->size/Maxspansize, s.blkno, s.len);
- buf = getbufchk(blkno, oldnblocks, Bmod, Tdata, d->qid.path);
+ buf = getbufchk(blkno, oldnblocks, Bwritable, Tdata, d->qid.path);
if(buf == nil)
return -1;
@@ -1318,7 +1318,7 @@
if((lastspansize+wbufsize+sizeof(Tag))%Rawblocksize > 0)
newnblocks++;
}
- nbuf = allocblocks(newnblocks, Bmod, Tdata, d->qid.path);
+ nbuf = allocblocks(newnblocks, Tdata, d->qid.path);
if(nbuf == nil){putbuf(buf);
return -1;
@@ -1381,7 +1381,7 @@
s32 n;
Iobuf *dbuf;
- dbuf = getbufchk(dblkno, 1, Bmod, Tdentry, qpath);
+ dbuf = getbufchk(dblkno, 1, Bwritable, Tdentry, qpath);
if(dbuf == nil)
return 0;
d = &dbuf->io->d;
--- a/all.h
+++ b/all.h
@@ -78,7 +78,7 @@
u8 *xiobuf; /* "real" buffer pointer */
Content *io; /* cast'able to contents */
};
- int flags;
+ u8 readonly;
};
extern u32 nbuckets; /* n hash buckets for i/o */
@@ -88,8 +88,8 @@
/* Iobuf routines - contents of the blocks in memory */
int checktag(Iobuf *p, u16 tag, u64 qpath);
-Iobuf* getbuf(u64 blkno, u16 len, int flags);
-Iobuf* getbufchk(u64 blkno, u16 len, int flags, int tag, u64 qpath);
+Iobuf* getbuf(u64 blkno, u16 len, u8 readonly, u8 freshalloc);
+Iobuf* getbufchk(u64 blkno, u16 len, u8 readonly, int tag, u64 qpath);
void iobufinit(void);
void putbuf(Iobuf *p);
void settag(Iobuf *p, int tag, u64 qpath);
@@ -96,7 +96,7 @@
void showbuf(Iobuf *p);
/* routines to manipulate the contents */
-Iobuf* allocblocks(u16 len, int flags, int tag, u64 qpath);
+Iobuf* allocblocks(u16 len, int tag, u64 qpath);
void freeblockbuf(Iobuf *buf);
void freeblocks(u64 blkno, u16 len, u16 tag, u64 qpath);
void fsok(int ok);
--- a/config.c
+++ b/config.c
@@ -91,7 +91,7 @@
Iobuf *buf;
s32 n;
- buf = getbufchk(bno, 1, Bmod, Tdata, Qpconfig);
+ buf = getbufchk(bno, 1, Bwritable, Tdata, Qpconfig);
if(buf == nil)
panic("cannot write config");n = snprint((s8*)buf->io->buf, Blocksize,
--- a/dat.h
+++ b/dat.h
@@ -386,15 +386,13 @@
/*
* flags to getbuf
- * As all writes except for the Super block are synchronous, Bimm is mostly obsolete.
*/
enum
{- Breadonly = (1<<0), /* read the block if miss */
- Bprobe = (1<<1), /* return null if miss */
- Bmod = (1<<2), /* set modified bit in buffer, needs writing */
- Bimm = (1<<3), /* set immediate bit in buffer */
- Bres = (1<<4), /* reserved, never renammed */
+ Breadonly = 1,/* read the block, cannot write to it */
+ Bwritable = 0,
+ Bfreshalloc = 1,/* newly allocated block, no contents on the disk */
+ Bused = 0,/* has contents on the disk */
};
/*
--- a/dentry.c
+++ b/dentry.c
@@ -76,13 +76,13 @@
return 0;
}
if(indblkno == 0){- if((buf = allocblocks(1, Bmod, tag, path)) == nil){+ if((buf = allocblocks(1, tag, path)) == nil){ dprint("%s",errstring[Efull]);return 0;
}
indblkno = buf->blkno;
}else{- if((buf = getbufchk(indblkno, 1, Bmod, tag, path)) == nil){+ if((buf = getbufchk(indblkno, 1, Bwritable, tag, path)) == nil){ dprint("updateindblock: %s",errstring[Ephase]);return 0;
}
@@ -180,7 +180,7 @@
if(iblkno == 0)
return;
- ibuf = getbufchk(iblkno, 1, Bmod, tag, qpath);
+ ibuf = getbufchk(iblkno, 1, Bwritable, tag, qpath);
if(ibuf == nil)
dprint("%s",errstring[Ephase]);if(tag == Tind0)
@@ -248,7 +248,7 @@
if(qpath < Qpusers || dblkno == 0)
return;
- dbuf = getbufchk(dblkno, 1, Bmod, Tdentry, qpath);
+ dbuf = getbufchk(dblkno, 1, Bwritable, Tdentry, qpath);
if(dbuf == nil)
dprint("%s",errstring[Ephase]);@@ -276,7 +276,7 @@
if(qpath < Qpusers || dblkno == 0)
return;
- dbuf = getbufchk(dblkno, 1, Bmod, Tdentry, qpath);
+ dbuf = getbufchk(dblkno, 1, Bwritable, Tdentry, qpath);
if(dbuf == nil)
dprint("%s",errstring[Ephase]);memcpy(&d, &dbuf->io->d, sizeof(Dentry));
@@ -311,7 +311,7 @@
if(qpath < Qpusers || dblkno == 0)
return;
/* clear the dentry to avoid links to removed content */
- dbuf = getbufchk(dblkno, 1, Bmod, Tdentry, qpath);
+ dbuf = getbufchk(dblkno, 1, Bwritable, Tdentry, qpath);
if(dbuf == nil)
dprint("%s",errstring[Ephase]);memcpy(&d, dbuf->io->buf, sizeof(Dentry));
@@ -329,7 +329,7 @@
if(s.blkno == 0)
break;
- buf = getbuf(s.blkno, 1, Breadonly);
+ buf = getbuf(s.blkno, 1, Breadonly, Bused);
child = &buf->io->d;
cqpath = child->qid.path;
mode = child->mode;
@@ -443,7 +443,7 @@
dprint("searchdir reli %d s.blkno %llud s.len %d\n",reli, s.blkno, s.len);
- *buf = getbuf(s.blkno, s.len, Breadonly);
+ *buf = getbuf(s.blkno, s.len, Breadonly, Bused);
if(*buf == nil){putbuf(*dbuf);
*dbuf = nil;
@@ -575,7 +575,7 @@
/* I cannot use truncatefile() below as it would
bfree() the blocks (which are already in the Extents frees)
and that would cause an inconsistency/panic */
- dbuf = getbufchk(dblkno, 1, Bmod, Tdentry, Qpfrees);
+ dbuf = getbufchk(dblkno, 1, Bwritable, Tdentry, Qpfrees);
if(dbuf == nil)
dprint("%s",errstring[Ephase]);d = &dbuf->io->d;
--- a/iobuf.c
+++ b/iobuf.c
@@ -55,7 +55,7 @@
Hiob.link->back is the oldest buffer that will be reused first.
*/
Iobuf *
-getbuf(u64 blkno, u16 len, int flags)
+getbuf(u64 blkno, u16 len, u8 readonly, u8 freshalloc)
{Hiob *hp;
Iobuf *s, *p;
@@ -62,16 +62,16 @@
s8 ncollisions;
if(len == 0){- panic("getbuf len == 0 blkno %llud flags %d caller %#p\n",- blkno, flags, getcallerpc(&blkno));
+ panic("getbuf len == 0 blkno %llud readonly %d caller %#p\n",+ blkno, readonly, getcallerpc(&blkno));
}
hp = &hiob[blkno%nbuckets];
if(chatty9p > 4)
dprint("getbuf blkno %llud len %d blkno%%nbuckets %llud pc 0x%p"- " hiob 0x%p hp 0x%p flags 0x%ux %d\n",
+ " hiob 0x%p hp 0x%p readonly %d\n",
blkno, len, blkno%nbuckets, getcallerpc(&blkno),
- hiob, hp, flags, flags);
+ hiob, hp, readonly);
qlock(hp);
s = hp->link;
if(s == nil)
@@ -110,12 +110,13 @@
free(p->xiobuf);
p->xiobuf = emalloc9p(len*Rawblocksize);
p->len = len;
- devread(blkno, p->xiobuf, len);
- if((flags & Bmod) == 0){+ if(freshalloc == 0)
+ devread(blkno, p->xiobuf, len);
+ if(readonly){chkwunlock(p);
rlock(p);
}
- }else if(flags & Bmod){+ }else if(readonly == 0){wlock(p);
if(chatty9p > 4)
dprint(" after wlock() blkno %llud\n", blkno);@@ -126,7 +127,7 @@
rlock(p);
}
decref(p);
- p->flags |= flags;
+ p->readonly = readonly;
return p;
}
p = p->fore;
@@ -133,11 +134,6 @@
if(p == s)
break;
}
- /* TODO Is this still needed? would be helpful for read ahead */
- /*if(flags == Bprobe){- qunlock(hp);
- return nil;
- }*/
/* maxed out our allowed number of collisions,
try to steal an older Iobuf without any ref's.
@@ -178,8 +174,9 @@
if(chatty9p > 4)
dprint(" after qunlock(hp) hp 0x%p blkno %llud\n",hp, blkno);
- devread(blkno, p->xiobuf, len);
- if((flags & Bmod) == 0){+ if(freshalloc == 0)
+ devread(blkno, p->xiobuf, len);
+ if(readonly){if(chatty9p > 4)
dprint("new buffer: switching from wlock() to rlock() blkno %llud\n", blkno);incref(p);
@@ -187,12 +184,12 @@
rlock(p);
decref(p);
}
- p->flags = flags;
+ p->readonly = readonly;
return p;
}
Iobuf *
-getbufchk(u64 blkno, u16 len, int flags, int tag, u64 qpath)
+getbufchk(u64 blkno, u16 len, u8 readonly, int tag, u64 qpath)
{Iobuf *b;
@@ -199,11 +196,11 @@
if(chatty9p > 4)
dprint("getbufchk caller pc 0x%p\n", getcallerpc(&blkno)); if(len == 0){- panic("getbufchk len == 0 blkno %llud flags %d tag %d"+ panic("getbufchk len == 0 blkno %llud readonly %d tag %d"" qpath %llud caller %#p\n",
- blkno, flags, tag, qpath, getcallerpc(&blkno));
+ blkno, readonly, tag, qpath, getcallerpc(&blkno));
}
- b = getbuf(blkno, len, flags);
+ b = getbuf(blkno, len, readonly, Bused);
if(b != nil)
if(checktag(b, tag, qpath) == 0){putbuf(b);
@@ -210,9 +207,9 @@
panic("checktag on %llud failed %s\n", blkno, errstring[Ephase]);}
if(b->io == nil)
- panic("b->io == nil blkno %llud flags %d tag %d"+ panic("b->io == nil blkno %llud readonly %d tag %d"" qpath %llud b->blkno %llud %d caller %#p\n",
- blkno, flags, tag, qpath, b->blkno, b->len,
+ blkno, readonly, tag, qpath, b->blkno, b->len,
getcallerpc(&blkno));
return b;
}
@@ -224,10 +221,10 @@
if(chatty9p > 4)
dprint("putbuf p->blkno 0x%d t->c->type %d devtab[t->c->type]->dc %c\n"- " p 0x%p p->flags 0x%ux %d\n"
+ " p 0x%p p->readonly %d\n"
" p->xiobuf 0x%p",
p->blkno, t->c->type, devtab[t->c->type]->dc,
- p, p->flags, p->flags, p->xiobuf);
+ p, p->readonly, p->xiobuf);
*/
void
@@ -246,7 +243,7 @@
return;
}
- buf = getbufchk(bno, 1, Bmod, Tdata, qpath);
+ buf = getbufchk(bno, 1, Bwritable, Tdata, qpath);
if(buf == nil){ panic("bkp: buf == nil\n");}
@@ -283,7 +280,13 @@
if(chatty9p > 4)
dprint("putbuf p->blkno %llud\n", p->blkno);- if(p->flags & Bmod){+
+ if(p->readonly){+ p->readonly = 0;
+ chkrunlock(p);
+ if(chatty9p > 4)
+ dprint(" .. runlock()'ed\n");+ }else{ if(canwlock(p)){ panic("putbuf: buffer not locked %llud\n", p->blkno);}
@@ -305,18 +308,9 @@
for(i=0; i<Nbkp; i++)
bkp(p, config.root.dest[i], Qproot0+i*3);
}
- }
-
- if(p->flags & Bmod){- p->flags = 0;
chkwunlock(p);
if(chatty9p > 4)
dprint(" .. wunlock()'ed\n");- }else{- p->flags = 0;
- chkrunlock(p);
- if(chatty9p > 4)
- dprint(" .. runlock()'ed\n");}
}
@@ -353,8 +347,8 @@
void
settag(Iobuf *p, int tagtype, u64 qpath)
{- if((p->flags & Bmod) == 0)
- panic("settag %s(%llux) tag/path=%s/%llud: not Bmod\n",+ if(p->readonly)
+ panic("settag %s(%llux) tag/path=%s/%llud: not Bwritable\n",devfile, (u64)p->blkno, tagnames[tagtype], qpath);
if(p->io == nil)
panic("settag %s(%llux) tag/path=%s/%llud: p->io == nil\n",@@ -412,11 +406,11 @@
}
dprint("showbuf p 0x%p blkno %llud len %d\n"" fore 0x%p back 0x%p\n"
- " xiobuf 0x%p flags 0x%x\n"
+ " xiobuf 0x%p readonly 0x%x\n"
" caller %#p\n",
p, p->blkno, p->len,
p->fore, p->back,
- p->xiobuf, p->flags,
+ p->xiobuf, p->readonly,
getcallerpc(&p));
if(p->io != nil)
showblock((u8*)p->io);
--- a/mafs.c
+++ b/mafs.c
@@ -42,7 +42,7 @@
static char *nets[8];
int doream, stdio, netc;
char buf[Namelen];
- int pid, ctl, n;
+ int pid, ctl;
progname = "mafs";
procname = "init";
--- a/sub.c
+++ b/sub.c
@@ -36,7 +36,7 @@
Iobuf *sb;
Superb *s;
- sb = getbufchk(Bsuper, 1, Bmod, Tdata, Qpsuper);
+ sb = getbufchk(Bsuper, 1, Bwritable, Tdata, Qpsuper);
if(sb == nil){ panic("newqpath: sb == nil\n");}
@@ -93,8 +93,9 @@
return 0;
}
+/* making the assumption that all allocations are not readonly */
Iobuf *
-allocblocks(u16 len, int flags, int tag, u64 qpath)
+allocblocks(u16 len, int tag, u64 qpath)
{u64 blkno;
Iobuf *buf;
@@ -106,7 +107,7 @@
if(chatty9p > 1)
dprint("alloc %d at %llud\n", len, blkno);/* cannot do getbufchk() unless we ream the whole disk at start */
- buf = getbuf(blkno, len, flags|Bmod);
+ buf = getbuf(blkno, len, Bwritable, Bfreshalloc);
/* clear the buf to avoid leaks on reuse */
memset(buf->io, 0, buf->len*Rawblocksize);
settag(buf, tag, qpath);
@@ -117,8 +118,8 @@
void
freeblockbuf(Iobuf *buf)
{- if((buf->flags&Bmod) == 0)
- panic("freeblockbuf without Bmod");+ if(buf->readonly)
+ panic("freeblockbuf without Bwritable");/* clear the buf to avoid leaks on reuse */
memset(buf->io, 0, buf->len*Rawblocksize);
@@ -137,7 +138,7 @@
blkno, config.nblocks);
return;
}
- buf = getbufchk(blkno, len, Bmod, tag, qpath);
+ buf = getbufchk(blkno, len, Bwritable, tag, qpath);
if(buf == nil)
dprint("%s",errstring[Ephase]);freeblockbuf(buf);
@@ -168,7 +169,7 @@
Iobuf *sb;
Superb *s;
- sb = getbufchk(Bsuper, 1, Bmod, Tdata, Qpsuper);
+ sb = getbufchk(Bsuper, 1, Bwritable, Tdata, Qpsuper);
if(sb == nil){ panic("newqpath: sb == nil\n");}
@@ -203,7 +204,7 @@
{Iobuf *b;
- b = getbuf(bno, len, Bmod);
+ b = getbuf(bno, len, Bwritable, Bfreshalloc);
memset(b->io, 0, len*Rawblocksize);
settag(b, Tdata, qpath);
putbuf(b);
@@ -216,7 +217,7 @@
Dentry *d;
u16 len;
- b = getbuf(dblkno, 1, Bmod);
+ b = getbuf(dblkno, 1, Bwritable, Bfreshalloc);
memset(b->io, 0, Rawblocksize);
settag(b, Tdentry, qpath);
d = &b->io->d;
@@ -260,7 +261,7 @@
"10006:glenda:glenda:\n"
"10007:manies::\n";
- b = getbuf(Badm, 1, Bmod);
+ b = getbuf(Badm, 1, Bwritable, Bfreshalloc);
memset(b->io, 0, Rawblocksize);
settag(b, Tdentry, Qpadm);
d = &b->io->d;
@@ -283,7 +284,7 @@
d->dspans[5] = (Spanid){Bdfrees, 1};putbuf(b);
- b = getbuf(Bbkp, 1, Bmod);
+ b = getbuf(Bbkp, 1, Bwritable, Bfreshalloc);
memset(b->io, 0, Rawblocksize);
settag(b, Tdentry, Qpbkp);
d = &b->io->d;
@@ -328,7 +329,7 @@
reamfile(Bdroot1, Qproot1, "root.1",
Blocksize, Bbkp, Qpbkp, config.root.dest[1]);
- b = getbuf(Busers, 1, Bmod);
+ b = getbuf(Busers, 1, Bwritable, Bfreshalloc);
if(b == nil)
panic("cannot get Busers");memset(b->io, 0, Rawblocksize);
@@ -343,7 +344,7 @@
Iobuf *b;
Dentry *d;
- b = getbuf(Broot, 1, Bmod);
+ b = getbuf(Broot, 1, Bwritable, Bfreshalloc);
if(b == nil)
panic("rootream b == nil");memset(b->io, 0, Rawblocksize);
@@ -372,7 +373,7 @@
u64 i, nbused;
nbused = Nbused;
- sbuf = getbuf(Bsuper, 1, Bmod);
+ sbuf = getbuf(Bsuper, 1, Bwritable, Bfreshalloc);
if(sbuf == nil)
panic("superream: sbuf == nil");memset(sbuf->io, 0, Rawblocksize);
@@ -454,7 +455,7 @@
superream(size, nblocks);
- iob = getbuf(Bmagicb, 1, Bmod);
+ iob = getbuf(Bmagicb, 1, Bwritable, Bfreshalloc);
snprint((s8*)iob->io->buf+256, Rawblocksize-256, "%s%d\n%llud\n",
magic, Rawblocksize, Maxspansize);
settag(iob, Tmagic, Qpmagic);