pnfsblock: write_pagelist handle zero invalid extents

For invalid extents, find other pages in the same fsblock and write them out.

[pnfsblock: write_begin]
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 233 insertions, 42 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 21efef7c2fd2..e56564d2ef95 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -35,6 +35,7 @@
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/bio.h>          /* struct bio */
+#include <linux/buffer_head.h>  /* various write calls */
 
 #include "blocklayout.h"
 
@@ -79,12 +80,8 @@ static int is_hole(struct pnfs_block_extent *be, sector_t isect)
  */
 static int is_writable(struct pnfs_block_extent *be, sector_t isect)
 {
-        if (be->be_state == PNFS_BLOCK_READWRITE_DATA)
-                return 1;
-        else if (be->be_state != PNFS_BLOCK_INVALID_DATA)
-                return 0;
-        else
-                return bl_is_sector_init(be->be_inval, isect);
+        return (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
+                be->be_state == PNFS_BLOCK_INVALID_DATA);
 }
 
 /* The data we are handed might be spread across several bios.  We need
@@ -353,6 +350,31 @@ static void mark_extents_written(struct pnfs_block_layout *bl,
         }
 }
 
+static void bl_end_io_write_zero(struct bio *bio, int err)
+{
+        struct parallel_io *par = 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;
+        struct nfs_write_data *wdata = (struct nfs_write_data *)par->data;
+
+        do {
+                struct page *page = bvec->bv_page;
+
+                if (--bvec >= bio->bi_io_vec)
+                        prefetchw(&bvec->bv_page->flags);
+                /* This is the zeroing page we added */
+                end_page_writeback(page);
+                page_cache_release(page);
+        } while (bvec >= bio->bi_io_vec);
+        if (!uptodate) {
+                if (!wdata->pnfs_error)
+                        wdata->pnfs_error = -EIO;
+                bl_set_lo_fail(wdata->lseg);
+        }
+        bio_put(bio);
+        put_parallel(par);
+}
+
 /* This is basically copied from mpage_end_io_read */
 static void bl_end_io_write(struct bio *bio, int err)
 {
@@ -379,11 +401,8 @@ static void bl_write_cleanup(struct work_struct *work)
         dprintk("%s enter\n", __func__);
         task = container_of(work, struct rpc_task, u.tk_work);
         wdata = container_of(task, struct nfs_write_data, task);
-        if (!wdata->task.tk_status) {
+        if (!wdata->pnfs_error) {
                 /* Marks for LAYOUTCOMMIT */
-                /* BUG - this should be called after each bio, not after
-                 * all finish, unless have some way of storing success/failure
-                 */
                 mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
                                      wdata->args.offset, wdata->args.count);
         }
@@ -391,38 +410,110 @@ static void bl_write_cleanup(struct work_struct *work)
 }
 
 /* Called when last of bios associated with a bl_write_pagelist call finishes */
-static void
-bl_end_par_io_write(void *data)
+static void bl_end_par_io_write(void *data)
 {
         struct nfs_write_data *wdata = data;
 
-        /* STUB - ignoring error handling */
         wdata->task.tk_status = 0;
         wdata->verf.committed = NFS_FILE_SYNC;
         INIT_WORK(&wdata->task.u.tk_work, bl_write_cleanup);
         schedule_work(&wdata->task.u.tk_work);
 }
 
+/* FIXME STUB - mark intersection of layout and page as bad, so is not
+ * used again.
+ */
+static void mark_bad_read(void)
+{
+        return;
+}
+
+/*
+ * map_block:  map a requested I/0 block (isect) into an offset in the LVM
+ * block_device
+ */
+static void
+map_block(struct buffer_head *bh, sector_t isect, struct pnfs_block_extent *be)
+{
+        dprintk("%s enter be=%p\n", __func__, be);
+
+        set_buffer_mapped(bh);
+        bh->b_bdev = be->be_mdev;
+        bh->b_blocknr = (isect - be->be_f_offset + be->be_v_offset) >>
+            (be->be_mdev->bd_inode->i_blkbits - SECTOR_SHIFT);
+
+        dprintk("%s isect %llu, bh->b_blocknr %ld, using bsize %Zd\n",
+                __func__, (unsigned long long)isect, (long)bh->b_blocknr,
+                bh->b_size);
+        return;
+}
+
+/* Given an unmapped page, zero it or read in page for COW, page is locked
+ * by caller.
+ */
+static int
+init_page_for_write(struct page *page, struct pnfs_block_extent *cow_read)
+{
+        struct buffer_head *bh = NULL;
+        int ret = 0;
+        sector_t isect;
+
+        dprintk("%s enter, %p\n", __func__, page);
+        BUG_ON(PageUptodate(page));
+        if (!cow_read) {
+                zero_user_segment(page, 0, PAGE_SIZE);
+                SetPageUptodate(page);
+                goto cleanup;
+        }
+
+        bh = alloc_page_buffers(page, PAGE_CACHE_SIZE, 0);
+        if (!bh) {
+                ret = -ENOMEM;
+                goto cleanup;
+        }
+
+        isect = (sector_t) page->index << PAGE_CACHE_SECTOR_SHIFT;
+        map_block(bh, isect, cow_read);
+        if (!bh_uptodate_or_lock(bh))
+                ret = bh_submit_read(bh);
+        if (ret)
+                goto cleanup;
+        SetPageUptodate(page);
+
+cleanup:
+        bl_put_extent(cow_read);
+        if (bh)
+                free_buffer_head(bh);
+        if (ret) {
+                /* Need to mark layout with bad read...should now
+                 * just use nfs4 for reads and writes.
+                 */
+                mark_bad_read();
+        }
+        return ret;
+}
+
 static enum pnfs_try_status
 bl_write_pagelist(struct nfs_write_data *wdata, int sync)
 {
-        int i;
+        int i, ret, npg_zero, pg_index, last = 0;
         struct bio *bio = NULL;
-        struct pnfs_block_extent *be = NULL;
-        sector_t isect, extent_length = 0;
+        struct pnfs_block_extent *be = NULL, *cow_read = NULL;
+        sector_t isect, last_isect = 0, extent_length = 0;
         struct parallel_io *par;
         loff_t offset = wdata->args.offset;
         size_t count = wdata->args.count;
         struct page **pages = wdata->args.pages;
-        int pg_index = wdata->args.pgbase >> PAGE_CACHE_SHIFT;
+        struct page *page;
+        pgoff_t index;
+        u64 temp;
+        int npg_per_block =
+            NFS_SERVER(wdata->inode)->pnfs_blksize >> PAGE_CACHE_SHIFT;
 
         dprintk("%s enter, %Zu@%lld\n", __func__, count, offset);
         /* At this point, wdata->pages is a (sequential) list of nfs_pages.
-         * We want to write each, and if there is an error remove it from
-         * list and call
-         * nfs_retry_request(req) to have it redone using nfs.
-         * QUEST? Do as block or per req?  Think have to do per block
-         * as part of end_bio
+         * We want to write each, and if there is an error set pnfs_error
+         * to have it redone using nfs.
          */
         par = alloc_parallel(wdata);
         if (!par)
@@ -433,7 +524,91 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
         /* At this point, have to be more careful with error handling */
 
         isect = (sector_t) ((offset & (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
-        for (i = pg_index; i < wdata->npages ; i++) {
+        be = bl_find_get_extent(BLK_LSEG2EXT(wdata->lseg), isect, &cow_read);
+        if (!be || !is_writable(be, isect)) {
+                dprintk("%s no matching extents!\n", __func__);
+                wdata->pnfs_error = -EINVAL;
+                goto out;
+        }
+
+        /* First page inside INVALID extent */
+        if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+                temp = offset >> PAGE_CACHE_SHIFT;
+                npg_zero = do_div(temp, npg_per_block);
+                isect = (sector_t) (((offset - npg_zero * PAGE_CACHE_SIZE) &
+                                     (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
+                extent_length = be->be_length - (isect - be->be_f_offset);
+
+fill_invalid_ext:
+                dprintk("%s need to zero %d pages\n", __func__, npg_zero);
+                for (;npg_zero > 0; npg_zero--) {
+                        /* page ref released in bl_end_io_write_zero */
+                        index = isect >> PAGE_CACHE_SECTOR_SHIFT;
+                        dprintk("%s zero %dth page: index %lu isect %llu\n",
+                                __func__, npg_zero, index,
+                                (unsigned long long)isect);
+                        page =
+                            find_or_create_page(wdata->inode->i_mapping, index,
+                                                GFP_NOFS);
+                        if (!page) {
+                                dprintk("%s oom\n", __func__);
+                                wdata->pnfs_error = -ENOMEM;
+                                goto out;
+                        }
+
+                        /* PageDirty: Other will write this out
+                         * PageWriteback: Other is writing this out
+                         * PageUptodate: It was read before
+                         * sector_initialized: already written out
+                         */
+                        if (PageDirty(page) || PageWriteback(page) ||
+                            bl_is_sector_init(be->be_inval, isect)) {
+                                print_page(page);
+                                unlock_page(page);
+                                page_cache_release(page);
+                                goto next_page;
+                        }
+                        if (!PageUptodate(page)) {
+                                /* New page, readin or zero it */
+                                init_page_for_write(page, cow_read);
+                        }
+                        set_page_writeback(page);
+                        unlock_page(page);
+
+                        ret = bl_mark_sectors_init(be->be_inval, isect,
+                                                       PAGE_CACHE_SECTORS,
+                                                       NULL);
+                        if (unlikely(ret)) {
+                                dprintk("%s bl_mark_sectors_init fail %d\n",
+                                        __func__, ret);
+                                end_page_writeback(page);
+                                page_cache_release(page);
+                                wdata->pnfs_error = ret;
+                                goto out;
+                        }
+                        bio = bl_add_page_to_bio(bio, npg_zero, WRITE,
+                                                 isect, page, be,
+                                                 bl_end_io_write_zero, par);
+                        if (IS_ERR(bio)) {
+                                wdata->pnfs_error = PTR_ERR(bio);
+                                goto out;
+                        }
+                        /* FIXME: This should be done in bi_end_io */
+                        mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
+                                             page->index << PAGE_CACHE_SHIFT,
+                                             PAGE_CACHE_SIZE);
+next_page:
+                        isect += PAGE_CACHE_SECTORS;
+                        extent_length -= PAGE_CACHE_SECTORS;
+                }
+                if (last)
+                        goto write_done;
+        }
+        bio = bl_submit_bio(WRITE, bio);
+
+        /* Middle pages */
+        pg_index = wdata->args.pgbase >> PAGE_CACHE_SHIFT;
+        for (i = pg_index; i < wdata->npages; i++) {
                 if (!extent_length) {
                         /* We've used up the previous extent */
                         bl_put_extent(be);
@@ -442,35 +617,51 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
                         be = bl_find_get_extent(BLK_LSEG2EXT(wdata->lseg),
                                              isect, NULL);
                         if (!be || !is_writable(be, isect)) {
-                                wdata->pnfs_error = -ENOMEM;
+                                wdata->pnfs_error = -EINVAL;
                                 goto out;
                         }
                         extent_length = be->be_length -
-                                (isect - be->be_f_offset);
+                            (isect - be->be_f_offset);
                 }
-                for (;;) {
-                        if (!bio) {
-                                bio = bio_alloc(GFP_NOIO, wdata->npages - i);
-                                if (!bio) {
-                                        wdata->pnfs_error = -ENOMEM;
-                                        goto out;
-                                }
-                                bio->bi_sector = isect - be->be_f_offset +
-                                        be->be_v_offset;
-                                bio->bi_bdev = be->be_mdev;
-                                bio->bi_end_io = bl_end_io_write;
-                                bio->bi_private = par;
+                if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+                        ret = bl_mark_sectors_init(be->be_inval, isect,
+                                                       PAGE_CACHE_SECTORS,
+                                                       NULL);
+                        if (unlikely(ret)) {
+                                dprintk("%s bl_mark_sectors_init fail %d\n",
+                                        __func__, ret);
+                                wdata->pnfs_error = ret;
+                                goto out;
                         }
-                        if (bio_add_page(bio, pages[i], PAGE_SIZE, 0))
-                                break;
-                        bio = bl_submit_bio(WRITE, bio);
+                }
+                bio = bl_add_page_to_bio(bio, wdata->npages - i, WRITE,
+                                         isect, pages[i], be,
+                                         bl_end_io_write, par);
+                if (IS_ERR(bio)) {
+                        wdata->pnfs_error = PTR_ERR(bio);
+                        goto out;
                 }
                 isect += PAGE_CACHE_SECTORS;
+                last_isect = isect;
                 extent_length -= PAGE_CACHE_SECTORS;
         }
-        wdata->res.count = (isect << SECTOR_SHIFT) - (offset);
-        if (count < wdata->res.count)
+
+        /* Last page inside INVALID extent */
+        if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+                bio = bl_submit_bio(WRITE, bio);
+                temp = last_isect >> PAGE_CACHE_SECTOR_SHIFT;
+                npg_zero = npg_per_block - do_div(temp, npg_per_block);
+                if (npg_zero < npg_per_block) {
+                        last = 1;
+                        goto fill_invalid_ext;
+                }
+        }
+
+write_done:
+        wdata->res.count = (last_isect << SECTOR_SHIFT) - (offset);
+        if (count < wdata->res.count) {
                 wdata->res.count = count;
+        }
 out:
         bl_put_extent(be);
         bl_submit_bio(WRITE, bio);