4 files changed, 63 insertions, 57 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index ff4a9175b4e1..bd194f645c52 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -872,7 +872,7 @@ static int trunc_start(struct gfs2_inode *ip, uint64_t size)
                         if (do_div(junk, sdp->sd_jbsize))
                                 error = truncator_journaled(ip, size);
                 } else if (size & (uint64_t)(sdp->sd_sb.sb_bsize - 1))
-                        error = gfs2_truncator_page(ip, size);
+                        error = gfs2_block_truncate_page(ip->i_vnode->i_mapping);
 
                 if (!error) {
                         ip->i_di.di_size = size;
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index da5a0b445188..d611b2ad2e97 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -385,7 +385,7 @@ static int gfs2_commit_write(struct file *file, struct page *page,
                         i_size_write(inode, file_size);
         } else {
                 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED)
-                        gfs2_page_add_databufs(sdp, page, from, to);
+                        gfs2_page_add_databufs(ip, page, from, to);
                 error = generic_commit_write(file, page, from, to);
                 if (error)
                         goto fail;
diff --git a/fs/gfs2/page.c b/fs/gfs2/page.c
index 05453c5a06f0..ea31bceac4f2 100644
--- a/fs/gfs2/page.c
+++ b/fs/gfs2/page.c
@@ -21,6 +21,7 @@
 #include "inode.h"
 #include "page.h"
 #include "trans.h"
+#include "ops_address.h"
 
 /**
  * gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
@@ -184,76 +185,81 @@ int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
 }
 
 /**
- * gfs2_truncator_page - truncate a partial data block in the page cache
- * @ip: the inode
- * @size: the size the file should be
+ * gfs2_block_truncate_page - Deal with zeroing out data for truncate
  *
- * Returns: errno
+ * This is partly borrowed from ext3.
  */
-
-int gfs2_truncator_page(struct gfs2_inode *ip, uint64_t size)
+int gfs2_block_truncate_page(struct address_space *mapping)
 {
+        struct inode *inode = mapping->host;
+        struct gfs2_inode *ip = get_v2ip(inode);
         struct gfs2_sbd *sdp = ip->i_sbd;
-        struct inode *inode = ip->i_vnode;
-        struct page *page;
+        loff_t from = inode->i_size;
+        unsigned long index = from >> PAGE_CACHE_SHIFT;
+        unsigned offset = from & (PAGE_CACHE_SIZE-1);
+        unsigned blocksize, iblock, length, pos;
         struct buffer_head *bh;
+        struct page *page;
         void *kaddr;
-        uint64_t lbn, dbn;
-        unsigned long index;
-        unsigned int offset;
-        unsigned int bufnum;
-        int new = 0;
-        int error;
-
-        lbn = size >> inode->i_blkbits;
-        error = gfs2_block_map(ip, lbn, &new, &dbn, NULL);
-        if (error || !dbn)
-                return error;
-
-        index = size >> PAGE_CACHE_SHIFT;
-        offset = size & (PAGE_CACHE_SIZE - 1);
-        bufnum = lbn - (index << (PAGE_CACHE_SHIFT - inode->i_blkbits));
-
-        page = read_cache_page(inode->i_mapping, index,
-                               (filler_t *)inode->i_mapping->a_ops->readpage,
-                               NULL);
-        if (IS_ERR(page))
-                return PTR_ERR(page);
-
-        lock_page(page);
-
-        if (!PageUptodate(page) || PageError(page)) {
-                error = -EIO;
-                goto out;
-        }
+        int err;
+
+        page = grab_cache_page(mapping, index);
+        if (!page)
+                return 0;
 
-        kaddr = kmap(page);
-        memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
-        kunmap(page);
+        blocksize = inode->i_sb->s_blocksize;
+        length = blocksize - (offset & (blocksize - 1));
+        iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 
         if (!page_has_buffers(page))
-                create_empty_buffers(page, 1 << inode->i_blkbits,
-                                     (1 << BH_Uptodate));
+                create_empty_buffers(page, blocksize, 0);
 
-        for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
-                /* Do nothing */;
+        /* Find the buffer that contains "offset" */
+        bh = page_buffers(page);
+        pos = blocksize;
+        while (offset >= pos) {
+                bh = bh->b_this_page;
+                iblock++;
+                pos += blocksize;
+        }
 
-        if (!buffer_mapped(bh))
-                map_bh(bh, inode->i_sb, dbn);
+        err = 0;
 
-        set_buffer_uptodate(bh);
-        if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED)
+        if (!buffer_mapped(bh)) {
+                gfs2_get_block(inode, iblock, bh, 0);
+                /* unmapped? It's a hole - nothing to do */
+                if (!buffer_mapped(bh))
+                        goto unlock;
+        }
+
+        /* Ok, it's mapped. Make sure it's up-to-date */
+        if (PageUptodate(page))
+                set_buffer_uptodate(bh);
+
+        if (!buffer_uptodate(bh)) {
+                err = -EIO;
+                ll_rw_block(READ, 1, &bh);
+                wait_on_buffer(bh);
+                /* Uhhuh. Read error. Complain and punt. */
+                if (!buffer_uptodate(bh))
+                        goto unlock;
+        }
+
+        if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED/* || gfs2_is_jdata(ip)*/)
                 gfs2_trans_add_databuf(sdp, bh);
-        mark_buffer_dirty(bh);
 
- out:
+        kaddr = kmap_atomic(page, KM_USER0);
+        memset(kaddr + offset, 0, length);
+        flush_dcache_page(page);
+        kunmap_atomic(kaddr, KM_USER0);
+
+unlock:
         unlock_page(page);
         page_cache_release(page);
-
-        return error;
+        return err;
 }
 
-void gfs2_page_add_databufs(struct gfs2_sbd *sdp, struct page *page,
+void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
                             unsigned int from, unsigned int to)
 {
         struct buffer_head *head = page_buffers(page);
@@ -267,7 +273,7 @@ void gfs2_page_add_databufs(struct gfs2_sbd *sdp, struct page *page,
                 end = start + bsize;
                 if (end <= from || start >= to)
                         continue;
-                gfs2_trans_add_databuf(sdp, bh);
+                gfs2_trans_add_databuf(ip->i_sbd, bh);
         }
 }
 
diff --git a/fs/gfs2/page.h b/fs/gfs2/page.h
index 7ad8c99ee0ef..346e296420c6 100644
--- a/fs/gfs2/page.h
+++ b/fs/gfs2/page.h
@@ -16,8 +16,8 @@ void gfs2_page_sync(struct gfs2_glock *gl, int flags);
 
 int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
                         uint64_t block, void *private);
-int gfs2_truncator_page(struct gfs2_inode *ip, uint64_t size);
-void gfs2_page_add_databufs(struct gfs2_sbd *sdp, struct page *page,
+int gfs2_block_truncate_page(struct address_space *mapping);
+void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
                             unsigned int from, unsigned int to);
 
 #endif /* __PAGE_DOT_H__ */