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xv6-public
提交 8d618cab 创建 作者: Robert Morris's avatar Robert Morris
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Merge branch 'master' of git+ssh://amsterdam.csail.mit.edu/home/am0/6.828/xv6

上级 12eeefc7 2b2c1971
隐藏空白字符变更
内嵌 并排
正在显示 包含 215 行增加 和 163 行删除
bio.c
浏览文件 @ 8d618cab
...@@ -80,6 +80,8 @@ bget(uint dev, uint sector) ...@@ -80,6 +80,8 @@ bget(uint dev, uint sector)
} }
// Not cached; recycle some non-busy and clean buffer. // Not cached; recycle some non-busy and clean buffer.
// "clean" because B_DIRTY and !B_BUSY means log.c
// hasn't yet committed the changes to the buffer.
for(b = bcache.head.prev; b != &bcache.head; b = b->prev){ for(b = bcache.head.prev; b != &bcache.head; b = b->prev){
if((b->flags & B_BUSY) == 0 && (b->flags & B_DIRTY) == 0){ if((b->flags & B_BUSY) == 0 && (b->flags & B_DIRTY) == 0){
b->dev = dev; b->dev = dev;
......
defs.h
浏览文件 @ 8d618cab
...@@ -81,8 +81,8 @@ void microdelay(int); ...@@ -81,8 +81,8 @@ void microdelay(int);
// log.c // log.c
void initlog(void); void initlog(void);
void log_write(struct buf*); void log_write(struct buf*);
void begin_trans(); void begin_op();
void commit_trans(); void end_op();
// mp.c // mp.c
extern int ismp; extern int ismp;
......
exec.c
浏览文件 @ 8d618cab
...@@ -18,9 +18,9 @@ exec(char *path, char **argv) ...@@ -18,9 +18,9 @@ exec(char *path, char **argv)
struct proghdr ph; struct proghdr ph;
pde_t *pgdir, *oldpgdir; pde_t *pgdir, *oldpgdir;
begin_trans(); begin_op();
if((ip = namei(path)) == 0){ if((ip = namei(path)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
ilock(ip); ilock(ip);
...@@ -50,7 +50,7 @@ exec(char *path, char **argv) ...@@ -50,7 +50,7 @@ exec(char *path, char **argv)
goto bad; goto bad;
} }
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
ip = 0; ip = 0;
// Allocate two pages at the next page boundary. // Allocate two pages at the next page boundary.
...@@ -101,7 +101,7 @@ exec(char *path, char **argv) ...@@ -101,7 +101,7 @@ exec(char *path, char **argv)
freevm(pgdir); freevm(pgdir);
if(ip){ if(ip){
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
} }
return -1; return -1;
} }
file.c
浏览文件 @ 8d618cab
...@@ -72,9 +72,9 @@ fileclose(struct file *f) ...@@ -72,9 +72,9 @@ fileclose(struct file *f)
if(ff.type == FD_PIPE) if(ff.type == FD_PIPE)
pipeclose(ff.pipe, ff.writable); pipeclose(ff.pipe, ff.writable);
else if(ff.type == FD_INODE){ else if(ff.type == FD_INODE){
begin_trans(); begin_op();
iput(ff.ip); iput(ff.ip);
commit_trans(); end_op();
} }
} }
...@@ -136,12 +136,12 @@ filewrite(struct file *f, char *addr, int n) ...@@ -136,12 +136,12 @@ filewrite(struct file *f, char *addr, int n)
if(n1 > max) if(n1 > max)
n1 = max; n1 = max;
begin_trans(); begin_op();
ilock(f->ip); ilock(f->ip);
if ((r = writei(f->ip, addr + i, f->off, n1)) > 0) if ((r = writei(f->ip, addr + i, f->off, n1)) > 0)
f->off += r; f->off += r;
iunlock(f->ip); iunlock(f->ip);
commit_trans(); end_op();
if(r < 0) if(r < 0)
break; break;
......
log.c
浏览文件 @ 8d618cab
...@@ -5,18 +5,19 @@ ...@@ -5,18 +5,19 @@
#include "fs.h" #include "fs.h"
#include "buf.h" #include "buf.h"
// Simple logging. Each file system system call // Simple logging that allows concurrent FS system calls.
// should be surrounded with begin_trans() and commit_trans() calls.
// //
// The log holds at most one transaction at a time. Commit forces // A log transaction contains the updates of multiple FS system
// the log (with commit record) to disk, then installs the affected // calls. The logging system only commits when there are
// blocks to disk, then erases the log. begin_trans() ensures that // no FS system calls active. Thus there is never
// only one system call can be in a transaction; others must wait. // any reasoning required about whether a commit might
// // write an uncommitted system call's updates to disk.
// Allowing only one transaction at a time means that the file //
// system code doesn't have to worry about the possibility of // A system call should call begin_op()/end_op() to mark
// one transaction reading a block that another one has modified, // its start and end. Usually begin_op() just increments
// for example an i-node block. // the count of in-progress FS system calls and returns.
// But if it thinks the log is close to running out, it
// sleeps until the last outstanding end_op() commits.
// //
// The log is a physical re-do log containing disk blocks. // The log is a physical re-do log containing disk blocks.
// The on-disk log format: // The on-disk log format:
...@@ -38,13 +39,15 @@ struct log { ...@@ -38,13 +39,15 @@ struct log {
struct spinlock lock; struct spinlock lock;
int start; int start;
int size; int size;
int busy; // a transaction is active int outstanding; // how many FS sys calls are executing.
int committing; // in commit(), please wait.
int dev; int dev;
struct logheader lh; struct logheader lh;
}; };
struct log log; struct log log;
static void recover_from_log(void); static void recover_from_log(void);
static void commit();
void void
initlog(void) initlog(void)
...@@ -117,36 +120,88 @@ recover_from_log(void) ...@@ -117,36 +120,88 @@ recover_from_log(void)
write_head(); // clear the log write_head(); // clear the log
} }
// called at the start of each FS system call.
void void
begin_trans(void) begin_op(void)
{ {
acquire(&log.lock); acquire(&log.lock);
while (log.busy) { while(1){
sleep(&log, &log.lock); if(log.committing){
sleep(&log, &log.lock);
} else if(log.lh.n + (log.outstanding+1)*MAXOPBLOCKS > LOGSIZE){
// this op might exhaust log space; wait for commit.
sleep(&log, &log.lock);
} else {
log.outstanding += 1;
release(&log.lock);
break;
}
} }
log.busy = 1;
release(&log.lock);
} }
// called at the end of each FS system call.
// commits if this was the last outstanding operation.
void void
commit_trans(void) end_op(void)
{
int do_commit = 0;
acquire(&log.lock);
log.outstanding -= 1;
if(log.committing)
panic("log.committing");
if(log.outstanding == 0){
do_commit = 1;
log.committing = 1;
} else {
// begin_op() may be waiting for log space.
wakeup(&log);
}
release(&log.lock);
if(do_commit){
// call commit w/o holding locks, since not allowed
// to sleep with locks.
commit();
acquire(&log.lock);
log.committing = 0;
wakeup(&log);
release(&log.lock);
}
}
// Copy modified blocks from cache to log.
static void
write_log(void)
{
int tail;
for (tail = 0; tail < log.lh.n; tail++) {
struct buf *to = bread(log.dev, log.start+tail+1); // log block
struct buf *from = bread(log.dev, log.lh.sector[tail]); // cache block
memmove(to->data, from->data, BSIZE);
bwrite(to); // write the log
brelse(from);
brelse(to);
}
}
static void
commit()
{ {
if (log.lh.n > 0) { if (log.lh.n > 0) {
write_log(); // Write modified blocks from cache to log
write_head(); // Write header to disk -- the real commit write_head(); // Write header to disk -- the real commit
install_trans(); // Now install writes to home locations install_trans(); // Now install writes to home locations
log.lh.n = 0; log.lh.n = 0;
write_head(); // Erase the transaction from the log write_head(); // Erase the transaction from the log
} }
acquire(&log.lock);
log.busy = 0;
wakeup(&log);
release(&log.lock);
} }
// Caller has modified b->data and is done with the buffer. // Caller has modified b->data and is done with the buffer.
// Append the block to the log and record the block number, // Record the block number and pin in the cache with B_DIRTY.
// but don't write the log header (which would commit the write). // commit()/write_log() will do the disk write.
//
// log_write() replaces bwrite(); a typical use is: // log_write() replaces bwrite(); a typical use is:
// bp = bread(...) // bp = bread(...)
// modify bp->data[] // modify bp->data[]
...@@ -159,21 +214,17 @@ log_write(struct buf *b) ...@@ -159,21 +214,17 @@ log_write(struct buf *b)
if (log.lh.n >= LOGSIZE || log.lh.n >= log.size - 1) if (log.lh.n >= LOGSIZE || log.lh.n >= log.size - 1)
panic("too big a transaction"); panic("too big a transaction");
if (!log.busy) if (log.outstanding < 1)
panic("write outside of trans"); panic("log_write outside of trans");
for (i = 0; i < log.lh.n; i++) { for (i = 0; i < log.lh.n; i++) {
if (log.lh.sector[i] == b->sector) // log absorbtion? if (log.lh.sector[i] == b->sector) // log absorbtion
break; break;
} }
log.lh.sector[i] = b->sector; log.lh.sector[i] = b->sector;
struct buf *lbuf = bread(b->dev, log.start+i+1);
memmove(lbuf->data, b->data, BSIZE);
bwrite(lbuf);
brelse(lbuf);
if (i == log.lh.n) if (i == log.lh.n)
log.lh.n++; log.lh.n++;
b->flags |= B_DIRTY; // XXX prevent eviction b->flags |= B_DIRTY; // prevent eviction
} }
//PAGEBREAK! //PAGEBREAK!
......
mkfs.c
浏览文件 @ 8d618cab
...@@ -13,7 +13,7 @@ ...@@ -13,7 +13,7 @@
#define static_assert(a, b) do { switch (0) case 0: case (a): ; } while (0) #define static_assert(a, b) do { switch (0) case 0: case (a): ; } while (0)
int nblocks = 985; int nblocks = (995-LOGSIZE);
int nlog = LOGSIZE; int nlog = LOGSIZE;
int ninodes = 200; int ninodes = 200;
int size = 1024; int size = 1024;
......
param.h
浏览文件 @ 8d618cab
...@@ -3,10 +3,11 @@ ...@@ -3,10 +3,11 @@
#define NCPU 8 // maximum number of CPUs #define NCPU 8 // maximum number of CPUs
#define NOFILE 16 // open files per process #define NOFILE 16 // open files per process
#define NFILE 100 // open files per system #define NFILE 100 // open files per system
#define NBUF 10 // size of disk block cache
#define NINODE 50 // maximum number of active i-nodes #define NINODE 50 // maximum number of active i-nodes
#define NDEV 10 // maximum major device number #define NDEV 10 // maximum major device number
#define ROOTDEV 1 // device number of file system root disk #define ROOTDEV 1 // device number of file system root disk
#define MAXARG 32 // max exec arguments #define MAXARG 32 // max exec arguments
#define LOGSIZE 10 // max data sectors in on-disk log #define MAXOPBLOCKS 10 // max # of blocks any FS op writes
#define LOGSIZE (MAXOPBLOCKS*3) // max data sectors in on-disk log
#define NBUF (MAXOPBLOCKS*3) // size of disk block cache (>= LOGSIZE)
proc.c
浏览文件 @ 8d618cab
...@@ -186,9 +186,9 @@ exit(void) ...@@ -186,9 +186,9 @@ exit(void)
} }
} }
begin_trans(); begin_op();
iput(proc->cwd); iput(proc->cwd);
commit_trans(); end_op();
proc->cwd = 0; proc->cwd = 0;
acquire(&ptable.lock); acquire(&ptable.lock);
......
sysfile.c
浏览文件 @ 8d618cab
...@@ -121,16 +121,16 @@ sys_link(void) ...@@ -121,16 +121,16 @@ sys_link(void)
if(argstr(0, &old) < 0 || argstr(1, &new) < 0) if(argstr(0, &old) < 0 || argstr(1, &new) < 0)
return -1; return -1;
begin_trans(); begin_op();
if((ip = namei(old)) == 0){ if((ip = namei(old)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
ilock(ip); ilock(ip);
if(ip->type == T_DIR){ if(ip->type == T_DIR){
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return -1; return -1;
} }
...@@ -148,7 +148,7 @@ sys_link(void) ...@@ -148,7 +148,7 @@ sys_link(void)
iunlockput(dp); iunlockput(dp);
iput(ip); iput(ip);
commit_trans(); end_op();
return 0; return 0;
...@@ -157,7 +157,7 @@ bad: ...@@ -157,7 +157,7 @@ bad:
ip->nlink--; ip->nlink--;
iupdate(ip); iupdate(ip);
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return -1; return -1;
} }
...@@ -189,9 +189,9 @@ sys_unlink(void) ...@@ -189,9 +189,9 @@ sys_unlink(void)
if(argstr(0, &path) < 0) if(argstr(0, &path) < 0)
return -1; return -1;
begin_trans(); begin_op();
if((dp = nameiparent(path, name)) == 0){ if((dp = nameiparent(path, name)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
...@@ -225,13 +225,13 @@ sys_unlink(void) ...@@ -225,13 +225,13 @@ sys_unlink(void)
iupdate(ip); iupdate(ip);
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return 0; return 0;
bad: bad:
iunlockput(dp); iunlockput(dp);
commit_trans(); end_op();
return -1; return -1;
} }
...@@ -291,23 +291,23 @@ sys_open(void) ...@@ -291,23 +291,23 @@ sys_open(void)
if(argstr(0, &path) < 0 || argint(1, &omode) < 0) if(argstr(0, &path) < 0 || argint(1, &omode) < 0)
return -1; return -1;
begin_trans(); begin_op();
if(omode & O_CREATE){ if(omode & O_CREATE){
ip = create(path, T_FILE, 0, 0); ip = create(path, T_FILE, 0, 0);
if(ip == 0){ if(ip == 0){
commit_trans(); end_op();
return -1; return -1;
} }
} else { } else {
if((ip = namei(path)) == 0){ if((ip = namei(path)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
ilock(ip); ilock(ip);
if(ip->type == T_DIR && omode != O_RDONLY){ if(ip->type == T_DIR && omode != O_RDONLY){
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return -1; return -1;
} }
} }
...@@ -316,11 +316,11 @@ sys_open(void) ...@@ -316,11 +316,11 @@ sys_open(void)
if(f) if(f)
fileclose(f); fileclose(f);
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return -1; return -1;
} }
iunlock(ip); iunlock(ip);
commit_trans(); end_op();
f->type = FD_INODE; f->type = FD_INODE;
f->ip = ip; f->ip = ip;
...@@ -336,13 +336,13 @@ sys_mkdir(void) ...@@ -336,13 +336,13 @@ sys_mkdir(void)
char *path; char *path;
struct inode *ip; struct inode *ip;
begin_trans(); begin_op();
if(argstr(0, &path) < 0 || (ip = create(path, T_DIR, 0, 0)) == 0){ if(argstr(0, &path) < 0 || (ip = create(path, T_DIR, 0, 0)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return 0; return 0;
} }
...@@ -354,16 +354,16 @@ sys_mknod(void) ...@@ -354,16 +354,16 @@ sys_mknod(void)
int len; int len;
int major, minor; int major, minor;
begin_trans(); begin_op();
if((len=argstr(0, &path)) < 0 || if((len=argstr(0, &path)) < 0 ||
argint(1, &major) < 0 || argint(1, &major) < 0 ||
argint(2, &minor) < 0 || argint(2, &minor) < 0 ||
(ip = create(path, T_DEV, major, minor)) == 0){ (ip = create(path, T_DEV, major, minor)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return 0; return 0;
} }
...@@ -373,20 +373,20 @@ sys_chdir(void) ...@@ -373,20 +373,20 @@ sys_chdir(void)
char *path; char *path;
struct inode *ip; struct inode *ip;
begin_trans(); begin_op();
if(argstr(0, &path) < 0 || (ip = namei(path)) == 0){ if(argstr(0, &path) < 0 || (ip = namei(path)) == 0){
commit_trans(); end_op();
return -1; return -1;
} }
ilock(ip); ilock(ip);
if(ip->type != T_DIR){ if(ip->type != T_DIR){
iunlockput(ip); iunlockput(ip);
commit_trans(); end_op();
return -1; return -1;
} }
iunlock(ip); iunlock(ip);
iput(proc->cwd); iput(proc->cwd);
commit_trans(); end_op();
proc->cwd = ip; proc->cwd = ip;
return 0; return 0;
} }
......
usertests.c
浏览文件 @ 8d618cab
...@@ -512,51 +512,56 @@ sharedfd(void) ...@@ -512,51 +512,56 @@ sharedfd(void)
} }
} }
// two processes write two different files at the same // four processes write different files at the same
// time, to test block allocation. // time, to test block allocation.
void void
twofiles(void) fourfiles(void)
{ {
int fd, pid, i, j, n, total; int fd, pid, i, j, n, total, pi;
char *names[] = { "f0", "f1", "f2", "f3" };
char *fname; char *fname;
printf(1, "twofiles test\n"); printf(1, "fourfiles test\n");
unlink("f1"); for(pi = 0; pi < 4; pi++){
unlink("f2"); fname = names[pi];
unlink(fname);
pid = fork(); pid = fork();
if(pid < 0){ if(pid < 0){
printf(1, "fork failed\n"); printf(1, "fork failed\n");
exit(); exit();
} }
fname = pid ? "f1" : "f2";
fd = open(fname, O_CREATE | O_RDWR);
if(fd < 0){
printf(1, "create failed\n");
exit();
}
memset(buf, pid?'p':'c', 512); if(pid == 0){
for(i = 0; i < 12; i++){ fd = open(fname, O_CREATE | O_RDWR);
if((n = write(fd, buf, 500)) != 500){ if(fd < 0){
printf(1, "write failed %d\n", n); printf(1, "create failed\n");
exit();
}
memset(buf, '0'+pi, 512);
for(i = 0; i < 12; i++){
if((n = write(fd, buf, 500)) != 500){
printf(1, "write failed %d\n", n);
exit();
}
}
exit(); exit();
} }
} }
close(fd);
if(pid) for(pi = 0; pi < 4; pi++){
wait(); wait();
else }
exit();
for(i = 0; i < 2; i++){ for(i = 0; i < 2; i++){
fd = open(i?"f1":"f2", 0); fname = names[i];
fd = open(fname, 0);
total = 0; total = 0;
while((n = read(fd, buf, sizeof(buf))) > 0){ while((n = read(fd, buf, sizeof(buf))) > 0){
for(j = 0; j < n; j++){ for(j = 0; j < n; j++){
if(buf[j] != (i?'p':'c')){ if(buf[j] != '0'+i){
printf(1, "wrong char\n"); printf(1, "wrong char\n");
exit(); exit();
} }
...@@ -568,87 +573,80 @@ twofiles(void) ...@@ -568,87 +573,80 @@ twofiles(void)
printf(1, "wrong length %d\n", total); printf(1, "wrong length %d\n", total);
exit(); exit();
} }
unlink(fname);
} }
unlink("f1"); printf(1, "fourfiles ok\n");
unlink("f2");
printf(1, "twofiles ok\n");
} }
// two processes create and delete different files in same directory // four processes create and delete different files in same directory
void void
createdelete(void) createdelete(void)
{ {
enum { N = 20 }; enum { N = 20 };
int pid, i, fd; int pid, i, fd, pi;
char name[32]; char name[32];
printf(1, "createdelete test\n"); printf(1, "createdelete test\n");
pid = fork();
if(pid < 0){
printf(1, "fork failed\n");
exit();
}
name[0] = pid ? 'p' : 'c'; for(pi = 0; pi < 4; pi++){
name[2] = '\0'; pid = fork();
for(i = 0; i < N; i++){ if(pid < 0){
name[1] = '0' + i; printf(1, "fork failed\n");
fd = open(name, O_CREATE | O_RDWR);
if(fd < 0){
printf(1, "create failed\n");
exit(); exit();
} }
close(fd);
if(i > 0 && (i % 2 ) == 0){ if(pid == 0){
name[1] = '0' + (i / 2); name[0] = 'p' + pi;
if(unlink(name) < 0){ name[2] = '\0';
printf(1, "unlink failed\n"); for(i = 0; i < N; i++){
exit(); name[1] = '0' + i;
fd = open(name, O_CREATE | O_RDWR);
if(fd < 0){
printf(1, "create failed\n");
exit();
}
close(fd);
if(i > 0 && (i % 2 ) == 0){
name[1] = '0' + (i / 2);
if(unlink(name) < 0){
printf(1, "unlink failed\n");
exit();
}
}
} }
exit();
} }
} }
if(pid==0) for(pi = 0; pi < 4; pi++){
exit();
else
wait(); wait();
}
name[0] = name[1] = name[2] = 0;
for(i = 0; i < N; i++){ for(i = 0; i < N; i++){
name[0] = 'p'; for(pi = 0; pi < 4; pi++){
name[1] = '0' + i; name[0] = 'p' + pi;
fd = open(name, 0); name[1] = '0' + i;
if((i == 0 || i >= N/2) && fd < 0){ fd = open(name, 0);
printf(1, "oops createdelete %s didn't exist\n", name); if((i == 0 || i >= N/2) && fd < 0){
exit(); printf(1, "oops createdelete %s didn't exist\n", name);
} else if((i >= 1 && i < N/2) && fd >= 0){ exit();
printf(1, "oops createdelete %s did exist\n", name); } else if((i >= 1 && i < N/2) && fd >= 0){
exit(); printf(1, "oops createdelete %s did exist\n", name);
} exit();
if(fd >= 0) }
close(fd); if(fd >= 0)
close(fd);
name[0] = 'c';
name[1] = '0' + i;
fd = open(name, 0);
if((i == 0 || i >= N/2) && fd < 0){
printf(1, "oops createdelete %s didn't exist\n", name);
exit();
} else if((i >= 1 && i < N/2) && fd >= 0){
printf(1, "oops createdelete %s did exist\n", name);
exit();
} }
if(fd >= 0)
close(fd);
} }
for(i = 0; i < N; i++){ for(i = 0; i < N; i++){
name[0] = 'p'; for(pi = 0; pi < 4; pi++){
name[1] = '0' + i; name[0] = 'p' + i;
unlink(name); name[1] = '0' + i;
name[0] = 'c'; unlink(name);
unlink(name); }
} }
printf(1, "createdelete ok\n"); printf(1, "createdelete ok\n");
...@@ -1716,6 +1714,12 @@ main(int argc, char *argv[]) ...@@ -1716,6 +1714,12 @@ main(int argc, char *argv[])
} }
close(open("usertests.ran", O_CREATE)); close(open("usertests.ran", O_CREATE));
createdelete();
linkunlink();
concreate();
fourfiles();
sharedfd();
bigargtest(); bigargtest();
bigwrite(); bigwrite();
bigargtest(); bigargtest();
...@@ -1741,18 +1745,12 @@ main(int argc, char *argv[]) ...@@ -1741,18 +1745,12 @@ main(int argc, char *argv[])
fourteen(); fourteen();
bigfile(); bigfile();
subdir(); subdir();
concreate();
linkunlink();
linktest(); linktest();
unlinkread(); unlinkread();
createdelete();
twofiles();
sharedfd();
dirfile(); dirfile();
iref(); iref();
forktest(); forktest();
bigdir(); // slow bigdir(); // slow
exectest(); exectest();
exit(); exit();
......
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