Re: [PATCH-e2fsprogs-resend] filefrag: fix fm_start in filefrag_fiemap loop

[Theodore Tso <tytso@mit.edu>]

On Thu, Jun 04, 2009 at 09:18:40AM +0800, Peng Tao wrote:
> When used with -v and the targeted file has more than 144 extents(double of
> the length of fm_extents array provided by buf), filefrag_fiemap loops and
> calls fiemap ioctl() multiple times to calculate the actual number of extents
> in a file. Each call to fiemap ioctl() uses  fm_start as the starting logical
> offset. The patch fixes fm_start in each loop( except for the first one) and
> makes the extent calculation correct for files with more that 144 extents.  
> 
> To produce the problem, first run filefrag -v on a highly fragmented file.
> Then change the buf size in filefrag_fiemap to make it large enough to have
> all the extent mapped in a single loop and run filefrag -v after recompiling.
> The former will produce a much smaller extent count because of the false
> fm_start used in the loop. And the two will produce different extent output
> since the 145th extent.

Thanks, applied.

						- Ted