保证文件操作的顺序(Guarantees of order of the operations on file)

 我想知道文件/文件系统上的操作顺序是否有任何保证。 
 
 考虑我有一个文件foo.dat ，我将其更新如下： 
 
 lseek(fd,pos_a,SEEK_SET);
 write(fd,data_a,size_a);  //< - Operation A
 lseek(fd,pos_b,SEEK_SET);
 write(fd,data_b,size_b);  //< - Operation B
 lseek(fd,pos_c,SEEK_SET);
 write(fd,data_c,size_c);  //< - Operation C
 
 这样我在文件A，B，C中进行更新。并且可能发生一些故障 - 软件崩溃或例如电源故障。 
 
 是否有任何保证，如果执行的操作是以相同的顺序完成的。 
 
 即没有任何东西或“A”或“A和B”或“A和B和C” 
 
 但不是像“A和C”或“B”这样的情况。 
 
 我知道如果我在A和B之间fsync(fd)并在A和C之间fsync(fd) ，但它也保证实际上是在文件系统上。 
 
 我不太关心数据的松散，而是关注它的一致性。 
 
 POSIX标准是否保证不会出现无序执行？ 
 
 所以： 
 
 
 
 有没有这样的保证？ 
 
 
 在POSIX平台上？ 
 
 
 在Windows平台上？ 
 
 
 如果没有什么保证（除了fsync ）我可以有？ 
 

I'd like to know if there any guarantees on the order of the operations on file/file system.
 
Consider I have a file foo.dat and I update it as following:
 
 lseek(fd,pos_a,SEEK_SET);
 write(fd,data_a,size_a);  //< - Operation A
 lseek(fd,pos_b,SEEK_SET);
 write(fd,data_b,size_b);  //< - Operation B
 lseek(fd,pos_c,SEEK_SET);
 write(fd,data_c,size_c);  //< - Operation C
 
Such that I do updates in file A, B, C. And some fault may occur - software crash or for example power failure.
 
Is there any guarantees that the operations if they are executed are done in same order.
 
i.e. That there would be either nothing or "A" or "A and B" or "A and B and C"
 
But not situations like "A and C" or "B" only.
 
I know that if I call between A and B fsync(fd) and same between A and C but it also guarantees that is actually on file system.
 
I less care about loose of data but rather about its consistency.
 
Does POSIX standard guarantees that there will be no out-of-order execution?
 
So:
 
 
 
As there any such guarantees?
 
 
On POSIX platform?
 
 
On Windows platform?
 
 
If not what guarantees (besides fsync) I can have?
 

原文：https://stackoverflow.com/questions/7463925