commit 67dbeee5fe9e2a855384048615bafe100e876f4c
parent 680c57a15c51c302d89aec134e25f08820d3f30d
Author: Russ Cox <rsc@swtch.com>
Date: Tue, 10 Oct 2017 13:49:37 -0400
acme: check file content before declaring file "modified since last read"
Bad remote file systems can change mtime unexpectedly,
and then there is the problem that git rebase and similar
operations like to change the files and then change them back,
modifying the mtimes but not the content.
Avoid spurious Put errors on both of those by checking file
content.
(False positive "modified since last read" make the real ones
difficult to notice.)
Diffstat:
23 files changed, 79 insertions(+), 13 deletions(-)
diff --git a/src/cmd/acme/acme.c b/src/cmd/acme/acme.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
/* for generating syms in mkfile only: */
diff --git a/src/cmd/acme/addr.c b/src/cmd/acme/addr.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/buff.c b/src/cmd/acme/buff.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
@@ -231,7 +232,7 @@ bufloader(void *v, uint q0, Rune *r, int nr)
}
uint
-loadfile(int fd, uint q0, int *nulls, int(*f)(void*, uint, Rune*, int), void *arg)
+loadfile(int fd, uint q0, int *nulls, int(*f)(void*, uint, Rune*, int), void *arg, DigestState *h)
{
char *p;
Rune *r;
@@ -253,6 +254,8 @@ loadfile(int fd, uint q0, int *nulls, int(*f)(void*, uint, Rune*, int), void *ar
warning(nil, "read error in Buffer.load");
break;
}
+ if(h != nil)
+ sha1((uchar*)p+m, n, nil, h);
m += n;
p[m] = 0;
l = m;
@@ -269,11 +272,11 @@ loadfile(int fd, uint q0, int *nulls, int(*f)(void*, uint, Rune*, int), void *ar
}
uint
-bufload(Buffer *b, uint q0, int fd, int *nulls)
+bufload(Buffer *b, uint q0, int fd, int *nulls, DigestState *h)
{
if(q0 > b->nc)
error("internal error: bufload");
- return loadfile(fd, q0, nulls, bufloader, b);
+ return loadfile(fd, q0, nulls, bufloader, b, h);
}
void
diff --git a/src/cmd/acme/cols.c b/src/cmd/acme/cols.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/dat.h b/src/cmd/acme/dat.h
@@ -105,7 +105,7 @@ struct Buffer
};
void bufinsert(Buffer*, uint, Rune*, uint);
void bufdelete(Buffer*, uint, uint);
-uint bufload(Buffer*, uint, int, int*);
+uint bufload(Buffer*, uint, int, int*, DigestState*);
void bufread(Buffer*, uint, Rune*, uint);
void bufclose(Buffer*);
void bufreset(Buffer*);
@@ -135,8 +135,9 @@ struct File
Rune *name; /* name of associated file */
int nname; /* size of name */
uvlong qidpath; /* of file when read */
- ulong mtime; /* of file when read */
+ ulong mtime; /* of file when read */
int dev; /* of file when read */
+ uchar sha1[20]; /* of file when read */
int unread; /* file has not been read from disk */
int editclean; /* mark clean after edit command */
@@ -152,7 +153,7 @@ void fileclose(File*);
void filedelete(File*, uint, uint);
void filedeltext(File*, Text*);
void fileinsert(File*, uint, Rune*, uint);
-uint fileload(File*, uint, int, int*);
+uint fileload(File*, uint, int, int*, DigestState*);
void filemark(File*);
void filereset(File*);
void filesetname(File*, Rune*, int);
diff --git a/src/cmd/acme/disk.c b/src/cmd/acme/disk.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/ecmd.c b/src/cmd/acme/ecmd.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "edit.h"
#include "fns.h"
@@ -336,7 +337,7 @@ e_cmd(Text *t, Cmd *cp)
}
elogdelete(f, q0, q1);
nulls = 0;
- loadfile(fd, q1, &nulls, readloader, f);
+ loadfile(fd, q1, &nulls, readloader, f, nil);
free(s);
close(fd);
if(nulls)
diff --git a/src/cmd/acme/edit.c b/src/cmd/acme/edit.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "edit.h"
#include "fns.h"
diff --git a/src/cmd/acme/elog.c b/src/cmd/acme/elog.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
#include "edit.h"
diff --git a/src/cmd/acme/exec.c b/src/cmd/acme/exec.c
@@ -9,6 +9,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include <9pclient.h>
#include "dat.h"
#include "fns.h"
@@ -635,6 +636,30 @@ get(Text *et, Text *t, Text *argt, int flag1, int _0, Rune *arg, int narg)
xfidlog(w, "get");
}
+static void
+checksha1(char *name, File *f, Dir *d)
+{
+ int fd, n;
+ DigestState *h;
+ uchar out[20];
+ uchar *buf;
+
+ fd = open(name, OREAD);
+ if(fd < 0)
+ return;
+ h = sha1(nil, 0, nil, nil);
+ buf = emalloc(8192);
+ while((n = read(fd, buf, 8192)) > 0)
+ sha1(buf, n, nil, h);
+ close(fd);
+ sha1(nil, 0, out, h);
+ if(memcmp(out, f->sha1, sizeof out) == 0) {
+ f->dev = d->dev;
+ f->qidpath = d->qid.path;
+ f->mtime = d->mtime;
+ }
+}
+
void
putfile(File *f, int q0, int q1, Rune *namer, int nname)
{
@@ -646,13 +671,15 @@ putfile(File *f, int q0, int q1, Rune *namer, int nname)
Dir *d, *d1;
Window *w;
int isapp;
+ DigestState *h;
w = f->curtext->w;
name = runetobyte(namer, nname);
d = dirstat(name);
if(d!=nil && runeeq(namer, nname, f->name, f->nname)){
- /* f->mtime+1 because when talking over NFS it's often off by a second */
- if(f->dev!=d->dev || f->qidpath!=d->qid.path || labs((long)(f->mtime-d->mtime)) > 1){
+ if(f->dev!=d->dev || f->qidpath!=d->qid.path || f->mtime != d->mtime)
+ checksha1(name, f, d);
+ if(f->dev!=d->dev || f->qidpath!=d->qid.path || f->mtime != d->mtime) {
if(f->unread)
warning(nil, "%s not written; file already exists\n", name);
else
@@ -679,6 +706,7 @@ putfile(File *f, int q0, int q1, Rune *namer, int nname)
s = fbufalloc();
free(d);
d = dirfstat(fd);
+ h = sha1(nil, 0, nil, nil);
isapp = (d!=nil && d->length>0 && (d->qid.type&QTAPPEND));
if(isapp){
warning(nil, "%s not written; file is append only\n", name);
@@ -691,6 +719,7 @@ putfile(File *f, int q0, int q1, Rune *namer, int nname)
n = BUFSIZE/UTFmax;
bufread(&f->b, q, r, n);
m = snprint(s, BUFSIZE+1, "%.*S", n, r);
+ sha1((uchar*)s, m, nil, h);
if(Bwrite(b, s, m) != m){
warning(nil, "can't write file %s: %r\n", name);
goto Rescue2;
@@ -730,6 +759,8 @@ putfile(File *f, int q0, int q1, Rune *namer, int nname)
f->qidpath = d->qid.path;
f->dev = d->dev;
f->mtime = d->mtime;
+ sha1(nil, 0, f->sha1, h);
+ h = nil;
f->mod = FALSE;
w->dirty = FALSE;
f->unread = FALSE;
@@ -741,6 +772,7 @@ putfile(File *f, int q0, int q1, Rune *namer, int nname)
}
fbuffree(s);
fbuffree(r);
+ free(h);
free(d);
free(namer);
free(name);
@@ -753,6 +785,7 @@ putfile(File *f, int q0, int q1, Rune *namer, int nname)
Bterm(b);
free(b);
}
+ free(h);
fbuffree(s);
fbuffree(r);
close(fd);
diff --git a/src/cmd/acme/file.c b/src/cmd/acme/file.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
@@ -163,11 +164,11 @@ fileunsetname(File *f, Buffer *delta)
}
uint
-fileload(File *f, uint p0, int fd, int *nulls)
+fileload(File *f, uint p0, int fd, int *nulls, DigestState *h)
{
if(f->seq > 0)
error("undo in file.load unimplemented");
- return bufload(&f->b, p0, fd, nulls);
+ return bufload(&f->b, p0, fd, nulls, h);
}
/* return sequence number of pending redo */
diff --git a/src/cmd/acme/fns.h b/src/cmd/acme/fns.h
@@ -25,7 +25,7 @@ void savemouse(Window*);
int restoremouse(Window*);
void clearmouse(void);
void allwindows(void(*)(Window*, void*), void*);
-uint loadfile(int, uint, int*, int(*)(void*, uint, Rune*, int), void*);
+uint loadfile(int, uint, int*, int(*)(void*, uint, Rune*, int), void*, DigestState*);
void movetodel(Window*);
Window* errorwin(Mntdir*, int);
diff --git a/src/cmd/acme/fsys.c b/src/cmd/acme/fsys.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/logf.c b/src/cmd/acme/logf.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/look.c b/src/cmd/acme/look.c
@@ -10,6 +10,7 @@
#include <regexp.h>
#include <9pclient.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/regx.c b/src/cmd/acme/regx.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/rows.c b/src/cmd/acme/rows.c
@@ -9,6 +9,7 @@
#include <fcall.h>
#include <bio.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/scrl.c b/src/cmd/acme/scrl.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/text.c b/src/cmd/acme/text.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include <complete.h>
#include "dat.h"
#include "fns.h"
@@ -198,6 +199,7 @@ textload(Text *t, uint q0, char *file, int setqid)
Dir *d, *dbuf;
char *tmp;
Text *u;
+ DigestState *h;
if(t->ncache!=0 || t->file->b.nc || t->w==nil || t!=&t->w->body)
error("text.load");
@@ -220,6 +222,7 @@ textload(Text *t, uint q0, char *file, int setqid)
goto Rescue;
}
nulls = FALSE;
+ h = nil;
if(d->qid.type & QTDIR){
/* this is checked in get() but it's possible the file changed underfoot */
if(t->file->ntext > 1){
@@ -264,9 +267,17 @@ textload(Text *t, uint q0, char *file, int setqid)
}else{
t->w->isdir = FALSE;
t->w->filemenu = TRUE;
- q1 = q0 + fileload(t->file, q0, fd, &nulls);
+ if(q0 == 0)
+ h = sha1(nil, 0, nil, nil);
+ q1 = q0 + fileload(t->file, q0, fd, &nulls, h);
}
if(setqid){
+ if(h != nil) {
+ sha1(nil, 0, t->file->sha1, h);
+ h = nil;
+ } else {
+ memset(t->file->sha1, 0, sizeof t->file->sha1);
+ }
t->file->dev = d->dev;
t->file->mtime = d->mtime;
t->file->qidpath = d->qid.path;
diff --git a/src/cmd/acme/time.c b/src/cmd/acme/time.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/util.c b/src/cmd/acme/util.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/wind.c b/src/cmd/acme/wind.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
diff --git a/src/cmd/acme/xfid.c b/src/cmd/acme/xfid.c
@@ -8,6 +8,7 @@
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
+#include <libsec.h>
#include "dat.h"
#include "fns.h"
