Messages in this thread |  | | Date | Wed, 10 Oct 2001 22:25:54 -0600 | From | Richard Gooch <> | Subject | Re: Dump corrupts ext2? |
| |
Chris Mason writes: > > > On Wednesday, October 10, 2001 07:33:55 PM -0600 Richard Gooch <rgooch@ras.ucalgary.ca> wrote: > > > Andreas Dilger writes: > > >> In Linus kernels 2.4.11+ the block devices and filesystems all use > >> the page cache, so no more coherency issues. > > > > Um, I thought that there wasn't going to be coherency? For example, if > > you open /dev/sda and /dev/sda1, they each have a separate cache. I > > remember some debate about this, and Linus pointed out how hard it was > > to make things coherent. > > They all use the page cache, but they still use different address > spaces.
OK, different "address spaces". I didn't recall the precise terminology :-)
> The block device and getblk share the same address space, so the metadata > and the block device are on the same cache, except for ext2 directories, > which act like files do. Each file has its own address space, so that > isn't coherent with the block device. > > In other words, block device reads with the FS mounted will probably > never give consistent results.
Indeed.
Regards,
Richard.... Permanent: rgooch@atnf.csiro.au Current: rgooch@ras.ucalgary.ca - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |