1 files changed, 245 insertions, 64 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 6a13ea64c447..2b10b36d1577 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -724,28 +724,55 @@ leave:
         return status;
 }
 
+/*
+ * While a write will already be ordering the data, a truncate will not.
+ * Thus, we need to explicitly order the zeroed pages.
+ */
+static handle_t *ocfs2_zero_start_ordered_transaction(struct inode *inode)
+{
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+        handle_t *handle = NULL;
+        int ret = 0;
+
+        if (!ocfs2_should_order_data(inode))
+                goto out;
+
+        handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
+        if (IS_ERR(handle)) {
+                ret = -ENOMEM;
+                mlog_errno(ret);
+                goto out;
+        }
+
+        ret = ocfs2_jbd2_file_inode(handle, inode);
+        if (ret < 0)
+                mlog_errno(ret);
+
+out:
+        if (ret) {
+                if (!IS_ERR(handle))
+                        ocfs2_commit_trans(osb, handle);
+                handle = ERR_PTR(ret);
+        }
+        return handle;
+}
+
 /* Some parts of this taken from generic_cont_expand, which turned out
  * to be too fragile to do exactly what we need without us having to
  * worry about recursive locking in ->write_begin() and ->write_end(). */
-static int ocfs2_write_zero_page(struct inode *inode,
-                                 u64 size)
+static int ocfs2_write_zero_page(struct inode *inode, u64 abs_from,
+                                 u64 abs_to)
 {
         struct address_space *mapping = inode->i_mapping;
         struct page *page;
-        unsigned long index;
-        unsigned int offset;
+        unsigned long index = abs_from >> PAGE_CACHE_SHIFT;
         handle_t *handle = NULL;
-        int ret;
+        int ret = 0;
+        unsigned zero_from, zero_to, block_start, block_end;
 
-        offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */
-        /* ugh.  in prepare/commit_write, if from==to==start of block, we
-        ** skip the prepare.  make sure we never send an offset for the start
-        ** of a block
-        */
-        if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) {
-                offset++;
-        }
-        index = size >> PAGE_CACHE_SHIFT;
+        BUG_ON(abs_from >= abs_to);
+        BUG_ON(abs_to > (((u64)index + 1) << PAGE_CACHE_SHIFT));
+        BUG_ON(abs_from & (inode->i_blkbits - 1));
 
         page = grab_cache_page(mapping, index);
         if (!page) {
@@ -754,31 +781,56 @@ static int ocfs2_write_zero_page(struct inode *inode,
                 goto out;
         }
 
-        ret = ocfs2_prepare_write_nolock(inode, page, offset, offset);
-        if (ret < 0) {
-                mlog_errno(ret);
-                goto out_unlock;
-        }
+        /* Get the offsets within the page that we want to zero */
+        zero_from = abs_from & (PAGE_CACHE_SIZE - 1);
+        zero_to = abs_to & (PAGE_CACHE_SIZE - 1);
+        if (!zero_to)
+                zero_to = PAGE_CACHE_SIZE;
 
-        if (ocfs2_should_order_data(inode)) {
-                handle = ocfs2_start_walk_page_trans(inode, page, offset,
-                                                     offset);
-                if (IS_ERR(handle)) {
-                        ret = PTR_ERR(handle);
-                        handle = NULL;
+        mlog(0,
+             "abs_from = %llu, abs_to = %llu, index = %lu, zero_from = %u, zero_to = %u\n",
+             (unsigned long long)abs_from, (unsigned long long)abs_to,
+             index, zero_from, zero_to);
+
+        /* We know that zero_from is block aligned */
+        for (block_start = zero_from; block_start < zero_to;
+             block_start = block_end) {
+                block_end = block_start + (1 << inode->i_blkbits);
+
+                /*
+                 * block_start is block-aligned.  Bump it by one to
+                 * force ocfs2_{prepare,commit}_write() to zero the
+                 * whole block.
+                 */
+                ret = ocfs2_prepare_write_nolock(inode, page,
+                                                 block_start + 1,
+                                                 block_start + 1);
+                if (ret < 0) {
+                        mlog_errno(ret);
                         goto out_unlock;
                 }
-        }
 
-        /* must not update i_size! */
-        ret = block_commit_write(page, offset, offset);
-        if (ret < 0)
-                mlog_errno(ret);
-        else
-                ret = 0;
+                if (!handle) {
+                        handle = ocfs2_zero_start_ordered_transaction(inode);
+                        if (IS_ERR(handle)) {
+                                ret = PTR_ERR(handle);
+                                handle = NULL;
+                                break;
+                        }
+                }
+
+                /* must not update i_size! */
+                ret = block_commit_write(page, block_start + 1,
+                                         block_start + 1);
+                if (ret < 0)
+                        mlog_errno(ret);
+                else
+                        ret = 0;
+        }
 
         if (handle)
                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
+
 out_unlock:
         unlock_page(page);
         page_cache_release(page);
@@ -786,22 +838,114 @@ out:
         return ret;
 }
 
-static int ocfs2_zero_extend(struct inode *inode,
-                             u64 zero_to_size)
+/*
+ * Find the next range to zero.  We do this in terms of bytes because
+ * that's what ocfs2_zero_extend() wants, and it is dealing with the
+ * pagecache.  We may return multiple extents.
+ *
+ * zero_start and zero_end are ocfs2_zero_extend()s current idea of what
+ * needs to be zeroed.  range_start and range_end return the next zeroing
+ * range.  A subsequent call should pass the previous range_end as its
+ * zero_start.  If range_end is 0, there's nothing to do.
+ *
+ * Unwritten extents are skipped over.  Refcounted extents are CoWd.
+ */
+static int ocfs2_zero_extend_get_range(struct inode *inode,
+                                       struct buffer_head *di_bh,
+                                       u64 zero_start, u64 zero_end,
+                                       u64 *range_start, u64 *range_end)
 {
-        int ret = 0;
-        u64 start_off;
-        struct super_block *sb = inode->i_sb;
+        int rc = 0, needs_cow = 0;
+        u32 p_cpos, zero_clusters = 0;
+        u32 zero_cpos =
+                zero_start >> OCFS2_SB(inode->i_sb)->s_clustersize_bits;
+        u32 last_cpos = ocfs2_clusters_for_bytes(inode->i_sb, zero_end);
+        unsigned int num_clusters = 0;
+        unsigned int ext_flags = 0;
 
-        start_off = ocfs2_align_bytes_to_blocks(sb, i_size_read(inode));
-        while (start_off < zero_to_size) {
-                ret = ocfs2_write_zero_page(inode, start_off);
-                if (ret < 0) {
-                        mlog_errno(ret);
+        while (zero_cpos < last_cpos) {
+                rc = ocfs2_get_clusters(inode, zero_cpos, &p_cpos,
+                                        &num_clusters, &ext_flags);
+                if (rc) {
+                        mlog_errno(rc);
+                        goto out;
+                }
+
+                if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN)) {
+                        zero_clusters = num_clusters;
+                        if (ext_flags & OCFS2_EXT_REFCOUNTED)
+                                needs_cow = 1;
+                        break;
+                }
+
+                zero_cpos += num_clusters;
+        }
+        if (!zero_clusters) {
+                *range_end = 0;
+                goto out;
+        }
+
+        while ((zero_cpos + zero_clusters) < last_cpos) {
+                rc = ocfs2_get_clusters(inode, zero_cpos + zero_clusters,
+                                        &p_cpos, &num_clusters,
+                                        &ext_flags);
+                if (rc) {
+                        mlog_errno(rc);
                         goto out;
                 }
 
-                start_off += sb->s_blocksize;
+                if (!p_cpos || (ext_flags & OCFS2_EXT_UNWRITTEN))
+                        break;
+                if (ext_flags & OCFS2_EXT_REFCOUNTED)
+                        needs_cow = 1;
+                zero_clusters += num_clusters;
+        }
+        if ((zero_cpos + zero_clusters) > last_cpos)
+                zero_clusters = last_cpos - zero_cpos;
+
+        if (needs_cow) {
+                rc = ocfs2_refcount_cow(inode, di_bh, zero_cpos, zero_clusters,
+                                        UINT_MAX);
+                if (rc) {
+                        mlog_errno(rc);
+                        goto out;
+                }
+        }
+
+        *range_start = ocfs2_clusters_to_bytes(inode->i_sb, zero_cpos);
+        *range_end = ocfs2_clusters_to_bytes(inode->i_sb,
+                                             zero_cpos + zero_clusters);
+
+out:
+        return rc;
+}
+
+/*
+ * Zero one range returned from ocfs2_zero_extend_get_range().  The caller
+ * has made sure that the entire range needs zeroing.
+ */
+static int ocfs2_zero_extend_range(struct inode *inode, u64 range_start,
+                                   u64 range_end)
+{
+        int rc = 0;
+        u64 next_pos;
+        u64 zero_pos = range_start;
+
+        mlog(0, "range_start = %llu, range_end = %llu\n",
+             (unsigned long long)range_start,
+             (unsigned long long)range_end);
+        BUG_ON(range_start >= range_end);
+
+        while (zero_pos < range_end) {
+                next_pos = (zero_pos & PAGE_CACHE_MASK) + PAGE_CACHE_SIZE;
+                if (next_pos > range_end)
+                        next_pos = range_end;
+                rc = ocfs2_write_zero_page(inode, zero_pos, next_pos);
+                if (rc < 0) {
+                        mlog_errno(rc);
+                        break;
+                }
+                zero_pos = next_pos;
 
                 /*
                  * Very large extends have the potential to lock up
@@ -810,16 +954,63 @@ static int ocfs2_zero_extend(struct inode *inode,
                 cond_resched();
         }
 
-out:
+        return rc;
+}
+
+int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh,
+                      loff_t zero_to_size)
+{
+        int ret = 0;
+        u64 zero_start, range_start = 0, range_end = 0;
+        struct super_block *sb = inode->i_sb;
+
+        zero_start = ocfs2_align_bytes_to_blocks(sb, i_size_read(inode));
+        mlog(0, "zero_start %llu for i_size %llu\n",
+             (unsigned long long)zero_start,
+             (unsigned long long)i_size_read(inode));
+        while (zero_start < zero_to_size) {
+                ret = ocfs2_zero_extend_get_range(inode, di_bh, zero_start,
+                                                  zero_to_size,
+                                                  &range_start,
+                                                  &range_end);
+                if (ret) {
+                        mlog_errno(ret);
+                        break;
+                }
+                if (!range_end)
+                        break;
+                /* Trim the ends */
+                if (range_start < zero_start)
+                        range_start = zero_start;
+                if (range_end > zero_to_size)
+                        range_end = zero_to_size;
+
+                ret = ocfs2_zero_extend_range(inode, range_start,
+                                              range_end);
+                if (ret) {
+                        mlog_errno(ret);
+                        break;
+                }
+                zero_start = range_end;
+        }
+
         return ret;
 }
 
-int ocfs2_extend_no_holes(struct inode *inode, u64 new_i_size, u64 zero_to)
+int ocfs2_extend_no_holes(struct inode *inode, struct buffer_head *di_bh,
+                          u64 new_i_size, u64 zero_to)
 {
         int ret;
         u32 clusters_to_add;
         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 
+        /*
+         * Only quota files call this without a bh, and they can't be
+         * refcounted.
+         */
+        BUG_ON(!di_bh && (oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
+        BUG_ON(!di_bh && !(oi->ip_flags & OCFS2_INODE_SYSTEM_FILE));
+
         clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size);
         if (clusters_to_add < oi->ip_clusters)
                 clusters_to_add = 0;
@@ -840,7 +1031,7 @@ int ocfs2_extend_no_holes(struct inode *inode, u64 new_i_size, u64 zero_to)
          * still need to zero the area between the old i_size and the
          * new i_size.
          */
-        ret = ocfs2_zero_extend(inode, zero_to);
+        ret = ocfs2_zero_extend(inode, di_bh, zero_to);
         if (ret < 0)
                 mlog_errno(ret);
 
@@ -862,27 +1053,15 @@ static int ocfs2_extend_file(struct inode *inode,
                 goto out;
 
         if (i_size_read(inode) == new_i_size)
-                goto out;
+                goto out;
         BUG_ON(new_i_size < i_size_read(inode));
 
         /*
-         * Fall through for converting inline data, even if the fs
-         * supports sparse files.
-         *
-         * The check for inline data here is legal - nobody can add
-         * the feature since we have i_mutex. We must check it again
-         * after acquiring ip_alloc_sem though, as paths like mmap
-         * might have raced us to converting the inode to extents.
-         */
-        if (!(oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
-            && ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
-                goto out_update_size;
-
-        /*
          * The alloc sem blocks people in read/write from reading our
          * allocation until we're done changing it. We depend on
          * i_mutex to block other extend/truncate calls while we're
-         * here.
+         * here.  We even have to hold it for sparse files because there
+         * might be some tail zeroing.
          */
         down_write(&oi->ip_alloc_sem);
 
@@ -899,14 +1078,16 @@ static int ocfs2_extend_file(struct inode *inode,
                 ret = ocfs2_convert_inline_data_to_extents(inode, di_bh);
                 if (ret) {
                         up_write(&oi->ip_alloc_sem);
-
                         mlog_errno(ret);
                         goto out;
                 }
         }
 
-        if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
-                ret = ocfs2_extend_no_holes(inode, new_i_size, new_i_size);
+        if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
+                ret = ocfs2_zero_extend(inode, di_bh, new_i_size);
+        else
+                ret = ocfs2_extend_no_holes(inode, di_bh, new_i_size,
+                                            new_i_size);
 
         up_write(&oi->ip_alloc_sem);