+static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
+ u32 cpos,
+ unsigned int *start,
+ unsigned int *end)
+{
+ unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
+
+ if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
+ unsigned int cpp;
+
+ cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
+
+ cluster_start = cpos % cpp;
+ cluster_start = cluster_start << osb->s_clustersize_bits;
+
+ cluster_end = cluster_start + osb->s_clustersize;
+ }
+
+ BUG_ON(cluster_start > PAGE_SIZE);
+ BUG_ON(cluster_end > PAGE_SIZE);
+
+ if (start)
+ *start = cluster_start;
+ if (end)
+ *end = cluster_end;
+}
+
+/*
+ * 'from' and 'to' are the region in the page to avoid zeroing.
+ *
+ * If pagesize > clustersize, this function will avoid zeroing outside
+ * of the cluster boundary.
+ *
+ * from == to == 0 is code for "zero the entire cluster region"
+ */
+static void ocfs2_clear_page_regions(struct page *page,
+ struct ocfs2_super *osb, u32 cpos,
+ unsigned from, unsigned to)
+{
+ void *kaddr;
+ unsigned int cluster_start, cluster_end;
+
+ ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
+
+ kaddr = kmap_atomic(page, KM_USER0);
+
+ if (from || to) {
+ if (from > cluster_start)
+ memset(kaddr + cluster_start, 0, from - cluster_start);
+ if (to < cluster_end)
+ memset(kaddr + to, 0, cluster_end - to);
+ } else {
+ memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
+ }
+
+ kunmap_atomic(kaddr, KM_USER0);
+}
+
+/*
+ * Nonsparse file systems fully allocate before we get to the write
+ * code. This prevents ocfs2_write() from tagging the write as an
+ * allocating one, which means ocfs2_map_page_blocks() might try to
+ * read-in the blocks at the tail of our file. Avoid reading them by
+ * testing i_size against each block offset.
+ */
+static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
+ unsigned int block_start)
+{
+ u64 offset = page_offset(page) + block_start;
+
+ if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
+ return 1;
+
+ if (i_size_read(inode) > offset)
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Some of this taken from block_prepare_write(). We already have our
+ * mapping by now though, and the entire write will be allocating or
+ * it won't, so not much need to use BH_New.
+ *
+ * This will also skip zeroing, which is handled externally.
+ */
+int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
+ struct inode *inode, unsigned int from,
+ unsigned int to, int new)
+{
+ int ret = 0;
+ struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
+ unsigned int block_end, block_start;
+ unsigned int bsize = 1 << inode->i_blkbits;
+
+ if (!page_has_buffers(page))
+ create_empty_buffers(page, bsize, 0);
+
+ head = page_buffers(page);
+ for (bh = head, block_start = 0; bh != head || !block_start;
+ bh = bh->b_this_page, block_start += bsize) {
+ block_end = block_start + bsize;
+
+ clear_buffer_new(bh);
+
+ /*
+ * Ignore blocks outside of our i/o range -
+ * they may belong to unallocated clusters.
+ */
+ if (block_start >= to || block_end <= from) {
+ if (PageUptodate(page))
+ set_buffer_uptodate(bh);
+ continue;
+ }
+
+ /*
+ * For an allocating write with cluster size >= page
+ * size, we always write the entire page.
+ */
+ if (new)
+ set_buffer_new(bh);
+
+ if (!buffer_mapped(bh)) {
+ map_bh(bh, inode->i_sb, *p_blkno);
+ unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
+ }
+
+ if (PageUptodate(page)) {
+ if (!buffer_uptodate(bh))
+ set_buffer_uptodate(bh);
+ } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
+ !buffer_new(bh) &&
+ ocfs2_should_read_blk(inode, page, block_start) &&
+ (block_start < from || block_end > to)) {
+ ll_rw_block(READ, 1, &bh);
+ *wait_bh++=bh;
+ }
+
+ *p_blkno = *p_blkno + 1;
+ }
+
+ /*
+ * If we issued read requests - let them complete.
+ */
+ while(wait_bh > wait) {
+ wait_on_buffer(*--wait_bh);
+ if (!buffer_uptodate(*wait_bh))
+ ret = -EIO;
+ }
+
+ if (ret == 0 || !new)
+ return ret;
+
+ /*
+ * If we get -EIO above, zero out any newly allocated blocks
+ * to avoid exposing stale data.
+ */
+ bh = head;
+ block_start = 0;
+ do {
+ block_end = block_start + bsize;
+ if (block_end <= from)
+ goto next_bh;
+ if (block_start >= to)
+ break;
+
+ zero_user(page, block_start, bh->b_size);
+ set_buffer_uptodate(bh);
+ mark_buffer_dirty(bh);
+
+next_bh:
+ block_start = block_end;
+ bh = bh->b_this_page;
+ } while (bh != head);
+
+ return ret;
+}
+
+#if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
+#define OCFS2_MAX_CTXT_PAGES 1
+#else
+#define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
+#endif
+
+#define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
+
+/*
+ * Describe the state of a single cluster to be written to.
+ */
+struct ocfs2_write_cluster_desc {
+ u32 c_cpos;
+ u32 c_phys;
+ /*
+ * Give this a unique field because c_phys eventually gets
+ * filled.
+ */
+ unsigned c_new;
+ unsigned c_unwritten;
+ unsigned c_needs_zero;
+};
+
+struct ocfs2_write_ctxt {
+ /* Logical cluster position / len of write */
+ u32 w_cpos;
+ u32 w_clen;
+
+ /* First cluster allocated in a nonsparse extend */
+ u32 w_first_new_cpos;
+
+ struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
+
+ /*
+ * This is true if page_size > cluster_size.
+ *
+ * It triggers a set of special cases during write which might
+ * have to deal with allocating writes to partial pages.
+ */
+ unsigned int w_large_pages;
+
+ /*
+ * Pages involved in this write.
+ *
+ * w_target_page is the page being written to by the user.
+ *
+ * w_pages is an array of pages which always contains
+ * w_target_page, and in the case of an allocating write with
+ * page_size < cluster size, it will contain zero'd and mapped
+ * pages adjacent to w_target_page which need to be written
+ * out in so that future reads from that region will get
+ * zero's.
+ */
+ struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
+ unsigned int w_num_pages;
+ struct page *w_target_page;
+
+ /*
+ * ocfs2_write_end() uses this to know what the real range to
+ * write in the target should be.
+ */
+ unsigned int w_target_from;
+ unsigned int w_target_to;
+
+ /*
+ * We could use journal_current_handle() but this is cleaner,
+ * IMHO -Mark
+ */
+ handle_t *w_handle;
+
+ struct buffer_head *w_di_bh;
+
+ struct ocfs2_cached_dealloc_ctxt w_dealloc;
+};
+
+void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
+{
+ int i;
+
+ for(i = 0; i < num_pages; i++) {
+ if (pages[i]) {
+ unlock_page(pages[i]);
+ mark_page_accessed(pages[i]);
+ page_cache_release(pages[i]);
+ }
+ }
+}
+
+static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
+{
+ ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
+
+ brelse(wc->w_di_bh);
+ kfree(wc);
+}
+
+static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
+ struct ocfs2_super *osb, loff_t pos,
+ unsigned len, struct buffer_head *di_bh)
+{
+ u32 cend;
+ struct ocfs2_write_ctxt *wc;
+
+ wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
+ if (!wc)
+ return -ENOMEM;
+
+ wc->w_cpos = pos >> osb->s_clustersize_bits;
+ wc->w_first_new_cpos = UINT_MAX;
+ cend = (pos + len - 1) >> osb->s_clustersize_bits;
+ wc->w_clen = cend - wc->w_cpos + 1;
+ get_bh(di_bh);
+ wc->w_di_bh = di_bh;
+
+ if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
+ wc->w_large_pages = 1;
+ else
+ wc->w_large_pages = 0;
+
+ ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
+
+ *wcp = wc;
+
+ return 0;
+}
+
+/*
+ * If a page has any new buffers, zero them out here, and mark them uptodate
+ * and dirty so they'll be written out (in order to prevent uninitialised
+ * block data from leaking). And clear the new bit.
+ */
+static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
+{
+ unsigned int block_start, block_end;
+ struct buffer_head *head, *bh;
+
+ BUG_ON(!PageLocked(page));
+ if (!page_has_buffers(page))
+ return;
+
+ bh = head = page_buffers(page);
+ block_start = 0;
+ do {
+ block_end = block_start + bh->b_size;
+
+ if (buffer_new(bh)) {
+ if (block_end > from && block_start < to) {
+ if (!PageUptodate(page)) {
+ unsigned start, end;
+
+ start = max(from, block_start);
+ end = min(to, block_end);
+
+ zero_user_segment(page, start, end);
+ set_buffer_uptodate(bh);
+ }
+
+ clear_buffer_new(bh);
+ mark_buffer_dirty(bh);
+ }
+ }
+
+ block_start = block_end;
+ bh = bh->b_this_page;
+ } while (bh != head);
+}
+
+/*
+ * Only called when we have a failure during allocating write to write
+ * zero's to the newly allocated region.
+ */
+static void ocfs2_write_failure(struct inode *inode,
+ struct ocfs2_write_ctxt *wc,
+ loff_t user_pos, unsigned user_len)
+{
+ int i;
+ unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
+ to = user_pos + user_len;
+ struct page *tmppage;
+
+ ocfs2_zero_new_buffers(wc->w_target_page, from, to);
+
+ for(i = 0; i < wc->w_num_pages; i++) {
+ tmppage = wc->w_pages[i];
+
+ if (page_has_buffers(tmppage)) {
+ if (ocfs2_should_order_data(inode))
+ ocfs2_jbd2_file_inode(wc->w_handle, inode);
+
+ block_commit_write(tmppage, from, to);
+ }
+ }
+}
+
+static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
+ struct ocfs2_write_ctxt *wc,
+ struct page *page, u32 cpos,
+ loff_t user_pos, unsigned user_len,
+ int new)
+{
+ int ret;
+ unsigned int map_from = 0, map_to = 0;
+ unsigned int cluster_start, cluster_end;
+ unsigned int user_data_from = 0, user_data_to = 0;
+
+ ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
+ &cluster_start, &cluster_end);
+
+ if (page == wc->w_target_page) {
+ map_from = user_pos & (PAGE_CACHE_SIZE - 1);
+ map_to = map_from + user_len;
+
+ if (new)
+ ret = ocfs2_map_page_blocks(page, p_blkno, inode,
+ cluster_start, cluster_end,
+ new);
+ else
+ ret = ocfs2_map_page_blocks(page, p_blkno, inode,
+ map_from, map_to, new);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ user_data_from = map_from;
+ user_data_to = map_to;
+ if (new) {
+ map_from = cluster_start;
+ map_to = cluster_end;
+ }
+ } else {
+ /*
+ * If we haven't allocated the new page yet, we
+ * shouldn't be writing it out without copying user
+ * data. This is likely a math error from the caller.
+ */
+ BUG_ON(!new);
+
+ map_from = cluster_start;
+ map_to = cluster_end;
+
+ ret = ocfs2_map_page_blocks(page, p_blkno, inode,
+ cluster_start, cluster_end, new);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ /*
+ * Parts of newly allocated pages need to be zero'd.
+ *
+ * Above, we have also rewritten 'to' and 'from' - as far as
+ * the rest of the function is concerned, the entire cluster
+ * range inside of a page needs to be written.
+ *
+ * We can skip this if the page is up to date - it's already
+ * been zero'd from being read in as a hole.
+ */
+ if (new && !PageUptodate(page))
+ ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
+ cpos, user_data_from, user_data_to);
+
+ flush_dcache_page(page);
+
+out:
+ return ret;
+}
+
+/*
+ * This function will only grab one clusters worth of pages.
+ */
+static int ocfs2_grab_pages_for_write(struct address_space *mapping,
+ struct ocfs2_write_ctxt *wc,
+ u32 cpos, loff_t user_pos, int new,
+ struct page *mmap_page)
+{
+ int ret = 0, i;
+ unsigned long start, target_index, index;
+ struct inode *inode = mapping->host;
+
+ target_index = user_pos >> PAGE_CACHE_SHIFT;
+
+ /*
+ * Figure out how many pages we'll be manipulating here. For
+ * non allocating write, we just change the one
+ * page. Otherwise, we'll need a whole clusters worth.
+ */
+ if (new) {
+ wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
+ start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
+ } else {
+ wc->w_num_pages = 1;
+ start = target_index;
+ }
+
+ for(i = 0; i < wc->w_num_pages; i++) {
+ index = start + i;
+
+ if (index == target_index && mmap_page) {
+ /*
+ * ocfs2_pagemkwrite() is a little different
+ * and wants us to directly use the page
+ * passed in.
+ */
+ lock_page(mmap_page);
+
+ if (mmap_page->mapping != mapping) {
+ unlock_page(mmap_page);
+ /*
+ * Sanity check - the locking in
+ * ocfs2_pagemkwrite() should ensure
+ * that this code doesn't trigger.
+ */
+ ret = -EINVAL;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ page_cache_get(mmap_page);
+ wc->w_pages[i] = mmap_page;
+ } else {
+ wc->w_pages[i] = find_or_create_page(mapping, index,
+ GFP_NOFS);
+ if (!wc->w_pages[i]) {
+ ret = -ENOMEM;
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ if (index == target_index)
+ wc->w_target_page = wc->w_pages[i];
+ }
+out:
+ return ret;
+}
+
+/*
+ * Prepare a single cluster for write one cluster into the file.
+ */
+static int ocfs2_write_cluster(struct address_space *mapping,
+ u32 phys, unsigned int unwritten,
+ unsigned int should_zero,
+ struct ocfs2_alloc_context *data_ac,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_write_ctxt *wc, u32 cpos,
+ loff_t user_pos, unsigned user_len)
+{
+ int ret, i, new;
+ u64 v_blkno, p_blkno;
+ struct inode *inode = mapping->host;
+ struct ocfs2_extent_tree et;
+
+ new = phys == 0 ? 1 : 0;
+ if (new) {
+ u32 tmp_pos;
+
+ /*
+ * This is safe to call with the page locks - it won't take
+ * any additional semaphores or cluster locks.
+ */
+ tmp_pos = cpos;
+ ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
+ &tmp_pos, 1, 0, wc->w_di_bh,
+ wc->w_handle, data_ac,
+ meta_ac, NULL);
+ /*
+ * This shouldn't happen because we must have already
+ * calculated the correct meta data allocation required. The
+ * internal tree allocation code should know how to increase
+ * transaction credits itself.
+ *
+ * If need be, we could handle -EAGAIN for a
+ * RESTART_TRANS here.
+ */
+ mlog_bug_on_msg(ret == -EAGAIN,
+ "Inode %llu: EAGAIN return during allocation.\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ } else if (unwritten) {
+ ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
+ wc->w_di_bh);
+ ret = ocfs2_mark_extent_written(inode, &et,
+ wc->w_handle, cpos, 1, phys,
+ meta_ac, &wc->w_dealloc);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ if (should_zero)
+ v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
+ else
+ v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
+
+ /*
+ * The only reason this should fail is due to an inability to
+ * find the extent added.
+ */
+ ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
+ NULL);
+ if (ret < 0) {
+ ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
+ "at logical block %llu",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ (unsigned long long)v_blkno);
+ goto out;
+ }
+
+ BUG_ON(p_blkno == 0);
+
+ for(i = 0; i < wc->w_num_pages; i++) {
+ int tmpret;
+
+ tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
+ wc->w_pages[i], cpos,
+ user_pos, user_len,
+ should_zero);
+ if (tmpret) {
+ mlog_errno(tmpret);
+ if (ret == 0)
+ ret = tmpret;
+ }
+ }
+
+ /*
+ * We only have cleanup to do in case of allocating write.
+ */
+ if (ret && new)
+ ocfs2_write_failure(inode, wc, user_pos, user_len);
+
+out:
+
+ return ret;
+}
+
+static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
+ struct ocfs2_alloc_context *data_ac,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_write_ctxt *wc,
+ loff_t pos, unsigned len)
+{
+ int ret, i;
+ loff_t cluster_off;
+ unsigned int local_len = len;
+ struct ocfs2_write_cluster_desc *desc;
+ struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
+
+ for (i = 0; i < wc->w_clen; i++) {
+ desc = &wc->w_desc[i];
+
+ /*
+ * We have to make sure that the total write passed in
+ * doesn't extend past a single cluster.
+ */
+ local_len = len;
+ cluster_off = pos & (osb->s_clustersize - 1);
+ if ((cluster_off + local_len) > osb->s_clustersize)
+ local_len = osb->s_clustersize - cluster_off;
+
+ ret = ocfs2_write_cluster(mapping, desc->c_phys,
+ desc->c_unwritten,
+ desc->c_needs_zero,
+ data_ac, meta_ac,
+ wc, desc->c_cpos, pos, local_len);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ len -= local_len;
+ pos += local_len;
+ }
+
+ ret = 0;
+out:
+ return ret;
+}
+
+/*
+ * ocfs2_write_end() wants to know which parts of the target page it
+ * should complete the write on. It's easiest to compute them ahead of
+ * time when a more complete view of the write is available.
+ */
+static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
+ struct ocfs2_write_ctxt *wc,
+ loff_t pos, unsigned len, int alloc)
+{
+ struct ocfs2_write_cluster_desc *desc;
+
+ wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
+ wc->w_target_to = wc->w_target_from + len;
+
+ if (alloc == 0)
+ return;
+
+ /*
+ * Allocating write - we may have different boundaries based
+ * on page size and cluster size.
+ *
+ * NOTE: We can no longer compute one value from the other as
+ * the actual write length and user provided length may be
+ * different.
+ */
+
+ if (wc->w_large_pages) {
+ /*
+ * We only care about the 1st and last cluster within
+ * our range and whether they should be zero'd or not. Either
+ * value may be extended out to the start/end of a
+ * newly allocated cluster.
+ */
+ desc = &wc->w_desc[0];
+ if (desc->c_needs_zero)
+ ocfs2_figure_cluster_boundaries(osb,
+ desc->c_cpos,
+ &wc->w_target_from,
+ NULL);
+
+ desc = &wc->w_desc[wc->w_clen - 1];
+ if (desc->c_needs_zero)
+ ocfs2_figure_cluster_boundaries(osb,
+ desc->c_cpos,
+ NULL,
+ &wc->w_target_to);
+ } else {
+ wc->w_target_from = 0;
+ wc->w_target_to = PAGE_CACHE_SIZE;
+ }
+}
+
+/*
+ * Populate each single-cluster write descriptor in the write context
+ * with information about the i/o to be done.
+ *
+ * Returns the number of clusters that will have to be allocated, as
+ * well as a worst case estimate of the number of extent records that
+ * would have to be created during a write to an unwritten region.
+ */
+static int ocfs2_populate_write_desc(struct inode *inode,
+ struct ocfs2_write_ctxt *wc,
+ unsigned int *clusters_to_alloc,
+ unsigned int *extents_to_split)
+{
+ int ret;
+ struct ocfs2_write_cluster_desc *desc;
+ unsigned int num_clusters = 0;
+ unsigned int ext_flags = 0;
+ u32 phys = 0;
+ int i;
+
+ *clusters_to_alloc = 0;
+ *extents_to_split = 0;
+
+ for (i = 0; i < wc->w_clen; i++) {
+ desc = &wc->w_desc[i];
+ desc->c_cpos = wc->w_cpos + i;
+
+ if (num_clusters == 0) {
+ /*
+ * Need to look up the next extent record.
+ */
+ ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
+ &num_clusters, &ext_flags);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ /* We should already CoW the refcountd extent. */
+ BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
+
+ /*
+ * Assume worst case - that we're writing in
+ * the middle of the extent.
+ *
+ * We can assume that the write proceeds from
+ * left to right, in which case the extent
+ * insert code is smart enough to coalesce the
+ * next splits into the previous records created.
+ */
+ if (ext_flags & OCFS2_EXT_UNWRITTEN)
+ *extents_to_split = *extents_to_split + 2;
+ } else if (phys) {
+ /*
+ * Only increment phys if it doesn't describe
+ * a hole.
+ */
+ phys++;
+ }
+
+ /*
+ * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
+ * file that got extended. w_first_new_cpos tells us
+ * where the newly allocated clusters are so we can
+ * zero them.
+ */
+ if (desc->c_cpos >= wc->w_first_new_cpos) {
+ BUG_ON(phys == 0);
+ desc->c_needs_zero = 1;
+ }
+
+ desc->c_phys = phys;
+ if (phys == 0) {
+ desc->c_new = 1;
+ desc->c_needs_zero = 1;
+ *clusters_to_alloc = *clusters_to_alloc + 1;
+ }
+
+ if (ext_flags & OCFS2_EXT_UNWRITTEN) {
+ desc->c_unwritten = 1;
+ desc->c_needs_zero = 1;
+ }
+
+ num_clusters--;
+ }
+
+ ret = 0;
+out:
+ return ret;
+}
+
+static int ocfs2_write_begin_inline(struct address_space *mapping,
+ struct inode *inode,
+ struct ocfs2_write_ctxt *wc)
+{
+ int ret;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct page *page;
+ handle_t *handle;
+ struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
+
+ page = find_or_create_page(mapping, 0, GFP_NOFS);
+ if (!page) {
+ ret = -ENOMEM;
+ mlog_errno(ret);
+ goto out;
+ }
+ /*
+ * If we don't set w_num_pages then this page won't get unlocked
+ * and freed on cleanup of the write context.
+ */
+ wc->w_pages[0] = wc->w_target_page = page;
+ wc->w_num_pages = 1;
+
+ handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (ret) {
+ ocfs2_commit_trans(osb, handle);
+
+ mlog_errno(ret);
+ goto out;
+ }
+
+ if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
+ ocfs2_set_inode_data_inline(inode, di);
+
+ if (!PageUptodate(page)) {
+ ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
+ if (ret) {
+ ocfs2_commit_trans(osb, handle);
+
+ goto out;
+ }
+ }
+
+ wc->w_handle = handle;
+out:
+ return ret;
+}
+
+int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
+{
+ struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+
+ if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
+ return 1;
+ return 0;
+}
+
+static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
+ struct inode *inode, loff_t pos,
+ unsigned len, struct page *mmap_page,
+ struct ocfs2_write_ctxt *wc)
+{
+ int ret, written = 0;
+ loff_t end = pos + len;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_dinode *di = NULL;
+
+ mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n",
+ (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos,
+ oi->ip_dyn_features);
+
+ /*
+ * Handle inodes which already have inline data 1st.
+ */
+ if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+ if (mmap_page == NULL &&
+ ocfs2_size_fits_inline_data(wc->w_di_bh, end))
+ goto do_inline_write;
+
+ /*
+ * The write won't fit - we have to give this inode an
+ * inline extent list now.
+ */
+ ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
+ if (ret)
+ mlog_errno(ret);
+ goto out;
+ }
+
+ /*
+ * Check whether the inode can accept inline data.
+ */
+ if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
+ return 0;
+
+ /*
+ * Check whether the write can fit.
+ */
+ di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
+ if (mmap_page ||
+ end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
+ return 0;
+
+do_inline_write:
+ ret = ocfs2_write_begin_inline(mapping, inode, wc);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ /*
+ * This signals to the caller that the data can be written
+ * inline.
+ */
+ written = 1;
+out:
+ return written ? written : ret;
+}
+
+/*
+ * This function only does anything for file systems which can't
+ * handle sparse files.
+ *
+ * What we want to do here is fill in any hole between the current end
+ * of allocation and the end of our write. That way the rest of the
+ * write path can treat it as an non-allocating write, which has no
+ * special case code for sparse/nonsparse files.
+ */
+static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos,
+ unsigned len,
+ struct ocfs2_write_ctxt *wc)
+{
+ int ret;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ loff_t newsize = pos + len;
+
+ if (ocfs2_sparse_alloc(osb))
+ return 0;
+
+ if (newsize <= i_size_read(inode))
+ return 0;
+
+ ret = ocfs2_extend_no_holes(inode, newsize, pos);
+ if (ret)
+ mlog_errno(ret);
+
+ wc->w_first_new_cpos =
+ ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
+
+ return ret;
+}
+
+int ocfs2_write_begin_nolock(struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata,
+ struct buffer_head *di_bh, struct page *mmap_page)
+{
+ int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
+ unsigned int clusters_to_alloc, extents_to_split;
+ struct ocfs2_write_ctxt *wc;
+ struct inode *inode = mapping->host;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_dinode *di;
+ struct ocfs2_alloc_context *data_ac = NULL;
+ struct ocfs2_alloc_context *meta_ac = NULL;
+ handle_t *handle;
+ struct ocfs2_extent_tree et;
+
+ ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
+ if (ret) {
+ mlog_errno(ret);
+ return ret;
+ }
+
+ if (ocfs2_supports_inline_data(osb)) {
+ ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
+ mmap_page, wc);
+ if (ret == 1) {
+ ret = 0;
+ goto success;
+ }
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_check_range_for_refcount(inode, pos, len);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ } else if (ret == 1) {
+ ret = ocfs2_refcount_cow(inode, di_bh,
+ wc->w_cpos, wc->w_clen, UINT_MAX);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
+ &extents_to_split);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
+
+ /*
+ * We set w_target_from, w_target_to here so that
+ * ocfs2_write_end() knows which range in the target page to
+ * write out. An allocation requires that we write the entire
+ * cluster range.
+ */
+ if (clusters_to_alloc || extents_to_split) {
+ /*
+ * XXX: We are stretching the limits of
+ * ocfs2_lock_allocators(). It greatly over-estimates
+ * the work to be done.
+ */
+ mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u,"
+ " clusters_to_add = %u, extents_to_split = %u\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ (long long)i_size_read(inode), le32_to_cpu(di->i_clusters),
+ clusters_to_alloc, extents_to_split);
+
+ ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
+ wc->w_di_bh);
+ ret = ocfs2_lock_allocators(inode, &et,
+ clusters_to_alloc, extents_to_split,
+ &data_ac, &meta_ac);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ credits = ocfs2_calc_extend_credits(inode->i_sb,
+ &di->id2.i_list,
+ clusters_to_alloc);
+
+ }
+
+ /*
+ * We have to zero sparse allocated clusters, unwritten extent clusters,
+ * and non-sparse clusters we just extended. For non-sparse writes,
+ * we know zeros will only be needed in the first and/or last cluster.
+ */
+ if (clusters_to_alloc || extents_to_split ||
+ (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
+ wc->w_desc[wc->w_clen - 1].c_needs_zero)))
+ cluster_of_pages = 1;
+ else
+ cluster_of_pages = 0;
+
+ ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
+
+ handle = ocfs2_start_trans(osb, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ mlog_errno(ret);
+ goto out;
+ }
+
+ wc->w_handle = handle;
+
+ if (clusters_to_alloc && vfs_dq_alloc_space_nodirty(inode,
+ ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc))) {
+ ret = -EDQUOT;
+ goto out_commit;
+ }
+ /*
+ * We don't want this to fail in ocfs2_write_end(), so do it
+ * here.
+ */
+ ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_quota;
+ }
+
+ /*
+ * Fill our page array first. That way we've grabbed enough so
+ * that we can zero and flush if we error after adding the
+ * extent.
+ */
+ ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
+ cluster_of_pages, mmap_page);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_quota;
+ }
+
+ ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
+ len);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_quota;
+ }
+
+ if (data_ac)
+ ocfs2_free_alloc_context(data_ac);
+ if (meta_ac)
+ ocfs2_free_alloc_context(meta_ac);
+
+success:
+ *pagep = wc->w_target_page;
+ *fsdata = wc;
+ return 0;
+out_quota:
+ if (clusters_to_alloc)
+ vfs_dq_free_space(inode,
+ ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
+out_commit:
+ ocfs2_commit_trans(osb, handle);
+
+out:
+ ocfs2_free_write_ctxt(wc);
+
+ if (data_ac)
+ ocfs2_free_alloc_context(data_ac);
+ if (meta_ac)
+ ocfs2_free_alloc_context(meta_ac);
+ return ret;
+}
+
+static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+ struct buffer_head *di_bh = NULL;
+ struct inode *inode = mapping->host;
+
+ ret = ocfs2_inode_lock(inode, &di_bh, 1);
+ if (ret) {
+ mlog_errno(ret);
+ return ret;
+ }
+
+ /*
+ * Take alloc sem here to prevent concurrent lookups. That way
+ * the mapping, zeroing and tree manipulation within
+ * ocfs2_write() will be safe against ->readpage(). This
+ * should also serve to lock out allocation from a shared
+ * writeable region.
+ */
+ down_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
+ fsdata, di_bh, NULL);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_fail;
+ }
+
+ brelse(di_bh);
+
+ return 0;
+
+out_fail:
+ up_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ brelse(di_bh);
+ ocfs2_inode_unlock(inode, 1);
+
+ return ret;
+}
+
+static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
+ unsigned len, unsigned *copied,
+ struct ocfs2_dinode *di,
+ struct ocfs2_write_ctxt *wc)
+{
+ void *kaddr;
+
+ if (unlikely(*copied < len)) {
+ if (!PageUptodate(wc->w_target_page)) {
+ *copied = 0;
+ return;
+ }
+ }
+
+ kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
+ memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ mlog(0, "Data written to inode at offset %llu. "
+ "id_count = %u, copied = %u, i_dyn_features = 0x%x\n",
+ (unsigned long long)pos, *copied,
+ le16_to_cpu(di->id2.i_data.id_count),
+ le16_to_cpu(di->i_dyn_features));
+}
+
+int ocfs2_write_end_nolock(struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ int i;
+ unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
+ struct inode *inode = mapping->host;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_write_ctxt *wc = fsdata;
+ struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
+ handle_t *handle = wc->w_handle;
+ struct page *tmppage;
+
+ if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+ ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
+ goto out_write_size;
+ }
+
+ if (unlikely(copied < len)) {
+ if (!PageUptodate(wc->w_target_page))
+ copied = 0;
+
+ ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
+ start+len);
+ }
+ flush_dcache_page(wc->w_target_page);
+
+ for(i = 0; i < wc->w_num_pages; i++) {
+ tmppage = wc->w_pages[i];
+
+ if (tmppage == wc->w_target_page) {
+ from = wc->w_target_from;
+ to = wc->w_target_to;
+
+ BUG_ON(from > PAGE_CACHE_SIZE ||
+ to > PAGE_CACHE_SIZE ||
+ to < from);
+ } else {
+ /*
+ * Pages adjacent to the target (if any) imply
+ * a hole-filling write in which case we want
+ * to flush their entire range.
+ */
+ from = 0;
+ to = PAGE_CACHE_SIZE;
+ }
+
+ if (page_has_buffers(tmppage)) {
+ if (ocfs2_should_order_data(inode))
+ ocfs2_jbd2_file_inode(wc->w_handle, inode);
+ block_commit_write(tmppage, from, to);
+ }
+ }
+
+out_write_size:
+ pos += copied;
+ if (pos > inode->i_size) {
+ i_size_write(inode, pos);
+ mark_inode_dirty(inode);
+ }
+ inode->i_blocks = ocfs2_inode_sector_count(inode);
+ di->i_size = cpu_to_le64((u64)i_size_read(inode));
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
+ di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
+ ocfs2_journal_dirty(handle, wc->w_di_bh);
+
+ ocfs2_commit_trans(osb, handle);
+
+ ocfs2_run_deallocs(osb, &wc->w_dealloc);
+
+ ocfs2_free_write_ctxt(wc);
+
+ return copied;
+}
+
+static int ocfs2_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ int ret;
+ struct inode *inode = mapping->host;
+
+ ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
+
+ up_write(&OCFS2_I(inode)->ip_alloc_sem);
+ ocfs2_inode_unlock(inode, 1);
+
+ return ret;
+}
+
+const struct address_space_operations ocfs2_aops = {
+ .readpage = ocfs2_readpage,
+ .readpages = ocfs2_readpages,
+ .writepage = ocfs2_writepage,
+ .write_begin = ocfs2_write_begin,
+ .write_end = ocfs2_write_end,
+ .bmap = ocfs2_bmap,
+ .sync_page = block_sync_page,
+ .direct_IO = ocfs2_direct_IO,
+ .invalidatepage = ocfs2_invalidatepage,
+ .releasepage = ocfs2_releasepage,
+ .migratepage = buffer_migrate_page,
+ .is_partially_uptodate = block_is_partially_uptodate,
+ .error_remove_page = generic_error_remove_page,