jim owens
2010-Jan-08 17:10 UTC
[RFC PATCH 00/01] Btrfs: add decompression code for direct I/O.
The following patch has the btrfs code changes/additions needed
to support reading compressed data in my directio code.
The code always runs in process context.
The callbacks:
int (*get_next_in)(struct bio_vec *vec, struct btrfs_inflate *icb);
int (*get_next_out)(struct bio_vec *vec, struct btrfs_inflate *icb);
track where we currently are in the compressed pages (get_next_in) and
uncompressed output user pages (get_next_out). (in) is always full pages,
(out) may be partial pages with offsets as the user input to direct I/O is
a set of memory vectors/lengths.
The callback:
void (*done_with_out)(struct bio_vec *vec, struct btrfs_inflate *icb);
is currently coded in directio as:
static void btrfs_dio_done_with_out(struct bio_vec *ovec,
struct btrfs_inflate *icb)
{
flush_dcache_page(ovec->bv_page);
if (!PageCompound(ovec->bv_page))
set_page_dirty_lock(ovec->bv_page);
page_cache_release(ovec->bv_page);
}
Again, this patch has no value without my directio code.
jim
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