Hello,
<div><br></div><div>I was looking at how a syscall read/write was done, and i found this : </div><div><br></div><div>   ....</div><div><div>   loff_t pos = file_pos_read(f.file);</div><div>   ret = vfs_read(f.file, buf, count, &amp;pos);</div>

<div>   file_pos_write(f.file, pos);</div><div>   fdput(f);</div></div><div>   ...</div><div><br></div><div>My questions are :</div><div><br></div><div>Where did the locking go? I would have imaginated something like :</div>

<div><br></div><div><div>   ....</div><div>   <b>lock(f);</b></div><div><div>   loff_t pos = file_pos_read(f.file);</div><div>   ret = vfs_read(f.file, buf, count, &amp;pos);</div><div>   file_pos_write(f.file, pos);</div>

<div>   fdput(f);</div></div><div>   <b>unlock(f);</b></div><div>   ...</div></div><div><br></div><div>If multiple threads try to read/write at the same time, they could read/write at the same offset ?</div><div><br></div>

<div>If my understanding are correct, is this POSIX compliant ?</div><div><br></div><div><br></div><div>thanks.</div><div><br></div>