On Fri, Jun 05, 2020 at 09:19:53AM +0800, Shukun Tan wrote: > Hi Dan, > > On 2020/6/2 21:54, Dan Carpenter wrote: > > Originally this code rejected any read less than 256 bytes. There > > is no need for this artificial limit. We should just use the normal > > helper functions to read a string from the kernel. > > > > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > --- > > v2: Use simple_read_from_buffer(). The v1 was slightly half arsed > > because I left the original check for: > > > > if (*pos) > > return 0; > > > > So it could result in partial reads. The new code means that if you > > want to read the buffer one byte at a time, that's fine or if you want > > to read it in one 256 byte chunk that's also fine. Plus it deletes 21 > > lines of code and is a lot cleaner. > > > > In fact, In our original design, we do not hope the user do the partial reads. > Thank you for your work, but I still insist on adding this limit. This not how POSIX filesystems work... :( Last time you said that this literally breaks cat. This doesn't break anything if the user chooses not to read a single byte at a time. That's obviously a crazy way to read a file. It just allows them to if they want. Or if they want to read 256 bytes at a time then that also works. My patch makes *everything* work. regards, dan carpenter
