On 05/25/2011 01:46 PM, Josef Bacik wrote:
On 05/25/2011 03:45 PM, Andreas Dilger wrote:
Most of the filesystem-specific ->llseek() methods don't do any error
checking on "origin" because this is handled at the sys_llseek() level,
and hasn't changed in many years.
I assume this patch is also dependent upon the "remove default_llseek()"
patch, so that the implementation of SEEK_DATA and SEEK_HOLE can be done
in only generic_file_llseek()?
Finally, while looking through the various ->llseek() methods I notice
that many filesystems return "i_size" for SEEK_END, which clearly does
not make sense for filesystems like ext3/ext4 htree, btrfs, etc that
use hash keys instead of byte offsets for doing directory traversal.
The comment at generic_file_llseek() is that it is intended for use by
regular files.
Should the ext4_llseek() code be changed to return 0x7ffffffff for the
SEEK_END value? That makes more sense compared to values returned for
SEEK_CUR so that an application can compare the current "offset" with
the final value for a progress bar.
So maybe we make SEEK_DATA/SEEK_HOLE only work on regular files and not
directories? Sunil what does solaris do? Thanks,
In Solaris the size of the directory appears to be equal to the number
of entries and the offset is the file#, so to speak. SEEK_DATA returns
the current offset and SEEK_HOLE the last one.
Just to be clear, I am not a Solaris expert. I just happen to have access
to it. ;)
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