Messages in this thread Patch in this message | | | Date | Fri, 24 Mar 2006 20:27:38 -0800 | From | Greg KH <> | Subject | [patch 14/20] dm: bio split bvec fix |
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-stable review patch. If anyone has any objections, please let us know.
------------------ From: Alasdair G Kergon <agk@redhat.com>
The code that handles bios that span table target boundaries by breaking them up into smaller bios will not split an individual struct bio_vec into more than two pieces. Sometimes more than that are required.
This patch adds a loop to break the second piece up into as many pieces as are necessary.
Cc: "Abhishek Gupta" <abhishekgupt@gmail.com> Cc: Dan Smith <danms@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> ---
drivers/md/dm.c | 45 +++++++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 20 deletions(-)
--- linux-2.6.16.orig/drivers/md/dm.c +++ linux-2.6.16/drivers/md/dm.c @@ -533,30 +533,35 @@ static void __clone_and_map(struct clone } else { /* - * Create two copy bios to deal with io that has - * been split across a target. + * Handle a bvec that must be split between two or more targets. */ struct bio_vec *bv = bio->bi_io_vec + ci->idx; + sector_t remaining = to_sector(bv->bv_len); + unsigned int offset = 0; - clone = split_bvec(bio, ci->sector, ci->idx, - bv->bv_offset, max); - __map_bio(ti, clone, tio); - - ci->sector += max; - ci->sector_count -= max; - ti = dm_table_find_target(ci->map, ci->sector); - - len = to_sector(bv->bv_len) - max; - clone = split_bvec(bio, ci->sector, ci->idx, - bv->bv_offset + to_bytes(max), len); - tio = alloc_tio(ci->md); - tio->io = ci->io; - tio->ti = ti; - memset(&tio->info, 0, sizeof(tio->info)); - __map_bio(ti, clone, tio); + do { + if (offset) { + ti = dm_table_find_target(ci->map, ci->sector); + max = max_io_len(ci->md, ci->sector, ti); + + tio = alloc_tio(ci->md); + tio->io = ci->io; + tio->ti = ti; + memset(&tio->info, 0, sizeof(tio->info)); + } + + len = min(remaining, max); + + clone = split_bvec(bio, ci->sector, ci->idx, + bv->bv_offset + offset, len); + + __map_bio(ti, clone, tio); + + ci->sector += len; + ci->sector_count -= len; + offset += to_bytes(len); + } while (remaining -= len); - ci->sector += len; - ci->sector_count -= len; ci->idx++; } } -- - 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/
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