On Tue, Apr 04 2017, Matthew Wilcox wrote:
> On Tue, Apr 04, 2017 at 12:25:46PM -0400, Jeff Layton wrote:
>> That said, I think giving more specific errors where we can is useful.
>> When your program is erroring out and writing 'I/O error' to the logs,
>> then how much time will your admins burn before they figure out that it
>> really failed because the filesystem was full?
>
> df is one of the first things I check ... a few years ago, I also learned
> to check df -i ... ;-)
>
> Anyway, given the decision to simply report the last error lets us do this
> implementation:
>
> void filemap_set_wb_error(struct address_space *mapping, int err)
> {
> struct inode *inode = mapping->host;
> unsigned int wb_err;
>
> if (!err)
> return;
> /*
> * This should be called with the error code that we want to return
> * on fsync. Thus, it should always be <= 0.
> */
> WARN_ON(err > 0 || err < -MAX_ERRNO);
>
> spin_lock(&inode->i_lock);
> wb_err = ((mapping->wb_err & ~MAX_ERRNO) + (1 << 12)) | -err;
Seriously? You are missing "MAX_ERRNO" (4095) together with "1 << 12"
(4096) in the one expression without a big comment saying why?
Surely:
> BUILD_BUG_ON_NOT_POWER_OF_2(MAX_ERRNO+1);
> wb_err = ((mapping->wb_err & ~MAX_ERRNO) + (MAX_ERRNO+1)) | -err;
NeilBrown
Attachment:
signature.asc
Description: PGP signature
