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tolerate out of disk when creating . and .. in mkdir()

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This commit is contained in:
Robert Morris 2022-08-23 08:52:15 -04:00
parent dc405cdb7b
commit 8621be8f3d
2 changed files with 21 additions and 9 deletions
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25
kernel/sysfile.c
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@ -272,24 +272,31 @@ create(char *path, short type, short major, short minor)
iupdate(ip);
if(type == T_DIR){ // Create . and .. entries.
dp->nlink++; // for ".."
iupdate(dp);
// No ip->nlink++ for ".": avoid cyclic ref count.
if(dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0)
panic("create dots");
goto fail;
}
if(dirlink(dp, name, ip->inum) < 0){
// oops. we don't need ip after all.
ip->nlink = 0;
iupdate(ip);
iunlockput(ip);
ip = 0;
if(dirlink(dp, name, ip->inum) < 0)
goto fail;
if(type == T_DIR){
// now that success is guaranteed:
dp->nlink++; // for ".."
iupdate(dp);
}
iunlockput(dp);
return ip;
fail:
// something went wrong. de-allocate ip.
ip->nlink = 0;
iupdate(ip);
iunlockput(ip);
iunlockput(dp);
return 0;
}
uint64