make mkdir crash-safer, as noticed by many students on midterm
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parent
e1626709d6
commit
f3e87bc838
1 changed files with 11 additions and 7 deletions
18
sysfile.c
18
sysfile.c
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@ -238,13 +238,6 @@ create(char *path, int canexist, short type, short major, short minor)
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ip->nlink = 1;
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iupdate(ip);
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if(dirlink(dp, name, ip->inum) < 0){
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ip->nlink = 0;
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iunlockput(ip);
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iunlockput(dp);
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return 0;
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}
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if(type == T_DIR){ // Create . and .. entries.
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dp->nlink++; // for ".."
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iupdate(dp);
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@ -252,6 +245,17 @@ create(char *path, int canexist, short type, short major, short minor)
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if(dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0)
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panic("create dots");
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}
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if(dirlink(dp, name, ip->inum) < 0){
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dp->nlink--;
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iupdate(dp);
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iunlockput(dp);
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ip->nlink = 0;
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iunlockput(ip);
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return 0;
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}
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iunlockput(dp);
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return ip;
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}
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