@@ -31,6 +31,7 @@
*/
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/bio.h> /* struct bio */
#include <linux/vmalloc.h>
#include "blocklayout.h"
@@ -40,9 +41,267 @@ MODULE_LICENSE("GPL");
MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
+static void print_page(struct page *page)
+{
+ dprintk("PRINTPAGE page %p\n", page);
+ dprintk(" PagePrivate %d\n", PagePrivate(page));
+ dprintk(" PageUptodate %d\n", PageUptodate(page));
+ dprintk(" PageError %d\n", PageError(page));
+ dprintk(" PageDirty %d\n", PageDirty(page));
+ dprintk(" PageReferenced %d\n", PageReferenced(page));
+ dprintk(" PageLocked %d\n", PageLocked(page));
+ dprintk(" PageWriteback %d\n", PageWriteback(page));
+ dprintk(" PageMappedToDisk %d\n", PageMappedToDisk(page));
+ dprintk("\n");
+}
+
+/* Given the be associated with isect, determine if page data needs to be
+ * initialized.
+ */
+static int is_hole(struct pnfs_block_extent *be, sector_t isect)
+{
+ if (be->be_state == PNFS_BLOCK_NONE_DATA)
+ return 1;
+ else if (be->be_state != PNFS_BLOCK_INVALID_DATA)
+ return 0;
+ else
+ return !is_sector_initialized(be->be_inval, isect);
+}
+
+static int
+dont_like_caller(struct nfs_page *req)
+{
+ if (atomic_read(&req->wb_complete)) {
+ /* Called by _multi */
+ return 1;
+ } else {
+ /* Called by _one */
+ return 0;
+ }
+}
+
+/* The data we are handed might be spread across several bios. We need
+ * to track when the last one is finished.
+ */
+struct parallel_io {
+ struct kref refcnt;
+ struct rpc_call_ops call_ops;
+ void (*pnfs_callback) (void *data);
+ void *data;
+};
+
+static inline struct parallel_io *alloc_parallel(void *data)
+{
+ struct parallel_io *rv;
+
+ rv = kmalloc(sizeof(*rv), GFP_KERNEL);
+ if (rv) {
+ rv->data = data;
+ kref_init(&rv->refcnt);
+ }
+ return rv;
+}
+
+static inline void get_parallel(struct parallel_io *p)
+{
+ kref_get(&p->refcnt);
+}
+
+static void destroy_parallel(struct kref *kref)
+{
+ struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
+
+ dprintk("%s enter\n", __func__);
+ p->pnfs_callback(p->data);
+ kfree(p);
+}
+
+static inline void put_parallel(struct parallel_io *p)
+{
+ kref_put(&p->refcnt, destroy_parallel);
+}
+
+static struct bio *
+bl_submit_bio(int rw, struct bio *bio)
+{
+ if (bio) {
+ get_parallel(bio->bi_private);
+ dprintk("%s submitting %s bio %u@%llu\n", __func__,
+ rw == READ ? "read" : "write",
+ bio->bi_size, (u64)bio->bi_sector);
+ submit_bio(rw, bio);
+ }
+ return NULL;
+}
+
+static inline void
+bl_done_with_rpage(struct page *page, const int ok)
+{
+ if (ok) {
+ ClearPagePnfsErr(page);
+ SetPageUptodate(page);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ SetPagePnfsErr(page);
+ }
+ /* Page is unlocked via rpc_release. Should really be done here. */
+}
+
+/* This is basically copied from mpage_end_io_read */
+static void bl_end_io_read(struct bio *bio, int err)
+{
+ void *data = bio->bi_private;
+ const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+
+ do {
+ struct page *page = bvec->bv_page;
+
+ if (--bvec >= bio->bi_io_vec)
+ prefetchw(&bvec->bv_page->flags);
+ bl_done_with_rpage(page, uptodate);
+ } while (bvec >= bio->bi_io_vec);
+ bio_put(bio);
+ put_parallel(data);
+}
+
+static void bl_read_cleanup(struct work_struct *work)
+{
+ struct rpc_task *task;
+ struct nfs_read_data *rdata;
+ dprintk("%s enter\n", __func__);
+ task = container_of(work, struct rpc_task, u.tk_work);
+ rdata = container_of(task, struct nfs_read_data, task);
+ pnfs_ld_read_done(rdata);
+}
+
+static void
+bl_end_par_io_read(void *data)
+{
+ struct nfs_read_data *rdata = data;
+
+ INIT_WORK(&rdata->task.u.tk_work, bl_read_cleanup);
+ schedule_work(&rdata->task.u.tk_work);
+}
+
+/* We don't want normal .rpc_call_done callback used, so we replace it
+ * with this stub.
+ */
+static void bl_rpc_do_nothing(struct rpc_task *task, void *calldata)
+{
+ return;
+}
+
static enum pnfs_try_status
bl_read_pagelist(struct nfs_read_data *rdata)
{
+ int i, hole;
+ struct bio *bio = NULL;
+ struct pnfs_block_extent *be = NULL, *cow_read = NULL;
+ sector_t isect, extent_length = 0;
+ struct parallel_io *par;
+ loff_t f_offset = rdata->args.offset;
+ size_t count = rdata->args.count;
+ struct page **pages = rdata->args.pages;
+ int pg_index = rdata->args.pgbase >> PAGE_CACHE_SHIFT;
+
+ dprintk("%s enter nr_pages %u offset %lld count %Zd\n", __func__,
+ rdata->npages, f_offset, count);
+
+ if (dont_like_caller(rdata->req)) {
+ dprintk("%s dont_like_caller failed\n", __func__);
+ goto use_mds;
+ }
+ if ((rdata->npages == 1) && PagePnfsErr(rdata->req->wb_page)) {
+ /* We want to fall back to mds in case of read_page
+ * after error on read_pages.
+ */
+ dprintk("%s PG_pnfserr set\n", __func__);
+ goto use_mds;
+ }
+ par = alloc_parallel(rdata);
+ if (!par)
+ goto use_mds;
+ par->call_ops = *rdata->mds_ops;
+ par->call_ops.rpc_call_done = bl_rpc_do_nothing;
+ par->pnfs_callback = bl_end_par_io_read;
+ /* At this point, we can no longer jump to use_mds */
+
+ isect = (sector_t) (f_offset >> 9);
+ /* Code assumes extents are page-aligned */
+ for (i = pg_index; i < rdata->npages; i++) {
+ if (!extent_length) {
+ /* We've used up the previous extent */
+ put_extent(be);
+ put_extent(cow_read);
+ bio = bl_submit_bio(READ, bio);
+ /* Get the next one */
+ be = find_get_extent(BLK_LSEG2EXT(rdata->lseg),
+ isect, &cow_read);
+ if (!be) {
+ /* Error out this page */
+ bl_done_with_rpage(pages[i], 0);
+ break;
+ }
+ extent_length = be->be_length -
+ (isect - be->be_f_offset);
+ if (cow_read) {
+ sector_t cow_length = cow_read->be_length -
+ (isect - cow_read->be_f_offset);
+ extent_length = min(extent_length, cow_length);
+ }
+ }
+ hole = is_hole(be, isect);
+ if (hole && !cow_read) {
+ bio = bl_submit_bio(READ, bio);
+ /* Fill hole w/ zeroes w/o accessing device */
+ dprintk("%s Zeroing page for hole\n", __func__);
+ zero_user(pages[i], 0,
+ min_t(int, PAGE_CACHE_SIZE, count));
+ print_page(pages[i]);
+ bl_done_with_rpage(pages[i], 1);
+ } else {
+ struct pnfs_block_extent *be_read;
+
+ be_read = (hole && cow_read) ? cow_read : be;
+ for (;;) {
+ if (!bio) {
+ bio = bio_alloc(GFP_NOIO, rdata->npages - i);
+ if (!bio) {
+ /* Error out this page */
+ bl_done_with_rpage(pages[i], 0);
+ break;
+ }
+ bio->bi_sector = isect -
+ be_read->be_f_offset +
+ be_read->be_v_offset;
+ bio->bi_bdev = be_read->be_mdev;
+ bio->bi_end_io = bl_end_io_read;
+ bio->bi_private = par;
+ }
+ if (bio_add_page(bio, pages[i], PAGE_SIZE, 0))
+ break;
+ bio = bl_submit_bio(READ, bio);
+ }
+ }
+ isect += PAGE_CACHE_SIZE >> 9;
+ extent_length -= PAGE_CACHE_SIZE >> 9;
+ }
+ if ((isect << 9) >= rdata->inode->i_size) {
+ rdata->res.eof = 1;
+ rdata->res.count = rdata->inode->i_size - f_offset;
+ } else {
+ rdata->res.count = (isect << 9) - f_offset;
+ }
+ put_extent(be);
+ put_extent(cow_read);
+ bl_submit_bio(READ, bio);
+ put_parallel(par);
+ return PNFS_ATTEMPTED;
+
+ use_mds:
+ dprintk("Giving up and using normal NFS\n");
return PNFS_NOT_ATTEMPTED;
}