nfs: add mirroring support to pgio layer

This patch adds mirrored write support to the pgio layer. The default
is to use one mirror, but pgio callers may define callbacks to change
this to any value up to the (arbitrarily selected) limit of 16.

The basic idea is to break out members of nfs_pageio_descriptor that cannot
be shared between mirrored DSes and put them in a new structure.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
This commit is contained in:
Weston Andros Adamson 2014-09-19 10:55:07 -04:00 committed by Tom Haynes
parent b57ff1303a
commit a7d42ddb30
9 changed files with 311 additions and 67 deletions

View file

@ -1646,8 +1646,8 @@ EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
* of bytes (maximum @req->wb_bytes) that can be coalesced.
*/
size_t
pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
struct nfs_page *req)
pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
struct nfs_page *prev, struct nfs_page *req)
{
unsigned int size;
u64 seg_end, req_start, seg_left;
@ -1729,10 +1729,12 @@ static void
pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
struct nfs_pgio_header *hdr)
{
struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[desc->pg_mirror_idx];
if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
list_splice_tail_init(&hdr->pages, &desc->pg_list);
list_splice_tail_init(&hdr->pages, &mirror->pg_list);
nfs_pageio_reset_write_mds(desc);
desc->pg_recoalesce = 1;
mirror->pg_recoalesce = 1;
}
nfs_pgio_data_destroy(hdr);
}
@ -1781,12 +1783,14 @@ EXPORT_SYMBOL_GPL(pnfs_writehdr_free);
int
pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
{
struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[desc->pg_mirror_idx];
struct nfs_pgio_header *hdr;
int ret;
hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
if (!hdr) {
desc->pg_completion_ops->error_cleanup(&desc->pg_list);
desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
return -ENOMEM;
}
nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
@ -1795,6 +1799,7 @@ pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
ret = nfs_generic_pgio(desc, hdr);
if (!ret)
pnfs_do_write(desc, hdr, desc->pg_ioflags);
return ret;
}
EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
@ -1839,10 +1844,13 @@ static void
pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
struct nfs_pgio_header *hdr)
{
struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[desc->pg_mirror_idx];
if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
list_splice_tail_init(&hdr->pages, &desc->pg_list);
list_splice_tail_init(&hdr->pages, &mirror->pg_list);
nfs_pageio_reset_read_mds(desc);
desc->pg_recoalesce = 1;
mirror->pg_recoalesce = 1;
}
nfs_pgio_data_destroy(hdr);
}
@ -1893,12 +1901,14 @@ EXPORT_SYMBOL_GPL(pnfs_readhdr_free);
int
pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
{
struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[desc->pg_mirror_idx];
struct nfs_pgio_header *hdr;
int ret;
hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
if (!hdr) {
desc->pg_completion_ops->error_cleanup(&desc->pg_list);
desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
return -ENOMEM;
}
nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);