zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/reiserfs/tail_conversion.c b/ap/os/linux/linux-3.4.x/fs/reiserfs/tail_conversion.c
new file mode 100644
index 0000000..5e2624d
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/reiserfs/tail_conversion.c
@@ -0,0 +1,280 @@
+/*
+ * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright details
+ */
+
+#include <linux/time.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include "reiserfs.h"
+
+/* access to tail : when one is going to read tail it must make sure, that is not running.
+ direct2indirect and indirect2direct can not run concurrently */
+
+/* Converts direct items to an unformatted node. Panics if file has no
+ tail. -ENOSPC if no disk space for conversion */
+/* path points to first direct item of the file regarless of how many of
+ them are there */
+int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode,
+ struct treepath *path, struct buffer_head *unbh,
+ loff_t tail_offset)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *up_to_date_bh;
+ struct item_head *p_le_ih = PATH_PITEM_HEAD(path);
+ unsigned long total_tail = 0;
+ struct cpu_key end_key; /* Key to search for the last byte of the
+ converted item. */
+ struct item_head ind_ih; /* new indirect item to be inserted or
+ key of unfm pointer to be pasted */
+ int blk_size, retval; /* returned value for reiserfs_insert_item and clones */
+ unp_t unfm_ptr; /* Handle on an unformatted node
+ that will be inserted in the
+ tree. */
+
+ BUG_ON(!th->t_trans_id);
+
+ REISERFS_SB(sb)->s_direct2indirect++;
+
+ blk_size = sb->s_blocksize;
+
+ /* and key to search for append or insert pointer to the new
+ unformatted node. */
+ copy_item_head(&ind_ih, p_le_ih);
+ set_le_ih_k_offset(&ind_ih, tail_offset);
+ set_le_ih_k_type(&ind_ih, TYPE_INDIRECT);
+
+ /* Set the key to search for the place for new unfm pointer */
+ make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4);
+
+ /* FIXME: we could avoid this */
+ if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) {
+ reiserfs_error(sb, "PAP-14030",
+ "pasted or inserted byte exists in "
+ "the tree %K. Use fsck to repair.", &end_key);
+ pathrelse(path);
+ return -EIO;
+ }
+
+ p_le_ih = PATH_PITEM_HEAD(path);
+
+ unfm_ptr = cpu_to_le32(unbh->b_blocknr);
+
+ if (is_statdata_le_ih(p_le_ih)) {
+ /* Insert new indirect item. */
+ set_ih_free_space(&ind_ih, 0); /* delete at nearest future */
+ put_ih_item_len(&ind_ih, UNFM_P_SIZE);
+ PATH_LAST_POSITION(path)++;
+ retval =
+ reiserfs_insert_item(th, path, &end_key, &ind_ih, inode,
+ (char *)&unfm_ptr);
+ } else {
+ /* Paste into last indirect item of an object. */
+ retval = reiserfs_paste_into_item(th, path, &end_key, inode,
+ (char *)&unfm_ptr,
+ UNFM_P_SIZE);
+ }
+ if (retval) {
+ return retval;
+ }
+ // note: from here there are two keys which have matching first
+ // three key components. They only differ by the fourth one.
+
+ /* Set the key to search for the direct items of the file */
+ make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT,
+ 4);
+
+ /* Move bytes from the direct items to the new unformatted node
+ and delete them. */
+ while (1) {
+ int tail_size;
+
+ /* end_key.k_offset is set so, that we will always have found
+ last item of the file */
+ if (search_for_position_by_key(sb, &end_key, path) ==
+ POSITION_FOUND)
+ reiserfs_panic(sb, "PAP-14050",
+ "direct item (%K) not found", &end_key);
+ p_le_ih = PATH_PITEM_HEAD(path);
+ RFALSE(!is_direct_le_ih(p_le_ih),
+ "vs-14055: direct item expected(%K), found %h",
+ &end_key, p_le_ih);
+ tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1))
+ + ih_item_len(p_le_ih) - 1;
+
+ /* we only send the unbh pointer if the buffer is not up to date.
+ ** this avoids overwriting good data from writepage() with old data
+ ** from the disk or buffer cache
+ ** Special case: unbh->b_page will be NULL if we are coming through
+ ** DIRECT_IO handler here.
+ */
+ if (!unbh->b_page || buffer_uptodate(unbh)
+ || PageUptodate(unbh->b_page)) {
+ up_to_date_bh = NULL;
+ } else {
+ up_to_date_bh = unbh;
+ }
+ retval = reiserfs_delete_item(th, path, &end_key, inode,
+ up_to_date_bh);
+
+ total_tail += retval;
+ if (tail_size == retval)
+ // done: file does not have direct items anymore
+ break;
+
+ }
+ /* if we've copied bytes from disk into the page, we need to zero
+ ** out the unused part of the block (it was not up to date before)
+ */
+ if (up_to_date_bh) {
+ unsigned pgoff =
+ (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
+ char *kaddr = kmap_atomic(up_to_date_bh->b_page);
+ memset(kaddr + pgoff, 0, blk_size - total_tail);
+ kunmap_atomic(kaddr);
+ }
+
+ REISERFS_I(inode)->i_first_direct_byte = U32_MAX;
+
+ return 0;
+}
+
+/* stolen from fs/buffer.c */
+void reiserfs_unmap_buffer(struct buffer_head *bh)
+{
+ lock_buffer(bh);
+ if (buffer_journaled(bh) || buffer_journal_dirty(bh)) {
+ BUG();
+ }
+ clear_buffer_dirty(bh);
+ /* Remove the buffer from whatever list it belongs to. We are mostly
+ interested in removing it from per-sb j_dirty_buffers list, to avoid
+ BUG() on attempt to write not mapped buffer */
+ if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) {
+ struct inode *inode = bh->b_page->mapping->host;
+ struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb);
+ spin_lock(&j->j_dirty_buffers_lock);
+ list_del_init(&bh->b_assoc_buffers);
+ reiserfs_free_jh(bh);
+ spin_unlock(&j->j_dirty_buffers_lock);
+ }
+ clear_buffer_mapped(bh);
+ clear_buffer_req(bh);
+ clear_buffer_new(bh);
+ bh->b_bdev = NULL;
+ unlock_buffer(bh);
+}
+
+/* this first locks inode (neither reads nor sync are permitted),
+ reads tail through page cache, insert direct item. When direct item
+ inserted successfully inode is left locked. Return value is always
+ what we expect from it (number of cut bytes). But when tail remains
+ in the unformatted node, we set mode to SKIP_BALANCING and unlock
+ inode */
+int indirect2direct(struct reiserfs_transaction_handle *th,
+ struct inode *inode, struct page *page,
+ struct treepath *path, /* path to the indirect item. */
+ const struct cpu_key *item_key, /* Key to look for
+ * unformatted node
+ * pointer to be cut. */
+ loff_t n_new_file_size, /* New file size. */
+ char *mode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct item_head s_ih;
+ unsigned long block_size = sb->s_blocksize;
+ char *tail;
+ int tail_len, round_tail_len;
+ loff_t pos, pos1; /* position of first byte of the tail */
+ struct cpu_key key;
+
+ BUG_ON(!th->t_trans_id);
+
+ REISERFS_SB(sb)->s_indirect2direct++;
+
+ *mode = M_SKIP_BALANCING;
+
+ /* store item head path points to. */
+ copy_item_head(&s_ih, PATH_PITEM_HEAD(path));
+
+ tail_len = (n_new_file_size & (block_size - 1));
+ if (get_inode_sd_version(inode) == STAT_DATA_V2)
+ round_tail_len = ROUND_UP(tail_len);
+ else
+ round_tail_len = tail_len;
+
+ pos =
+ le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE -
+ 1) * sb->s_blocksize;
+ pos1 = pos;
+
+ // we are protected by i_mutex. The tail can not disapper, not
+ // append can be done either
+ // we are in truncate or packing tail in file_release
+
+ tail = (char *)kmap(page); /* this can schedule */
+
+ if (path_changed(&s_ih, path)) {
+ /* re-search indirect item */
+ if (search_for_position_by_key(sb, item_key, path)
+ == POSITION_NOT_FOUND)
+ reiserfs_panic(sb, "PAP-5520",
+ "item to be converted %K does not exist",
+ item_key);
+ copy_item_head(&s_ih, PATH_PITEM_HEAD(path));
+#ifdef CONFIG_REISERFS_CHECK
+ pos = le_ih_k_offset(&s_ih) - 1 +
+ (ih_item_len(&s_ih) / UNFM_P_SIZE -
+ 1) * sb->s_blocksize;
+ if (pos != pos1)
+ reiserfs_panic(sb, "vs-5530", "tail position "
+ "changed while we were reading it");
+#endif
+ }
+
+ /* Set direct item header to insert. */
+ make_le_item_head(&s_ih, NULL, get_inode_item_key_version(inode),
+ pos1 + 1, TYPE_DIRECT, round_tail_len,
+ 0xffff /*ih_free_space */ );
+
+ /* we want a pointer to the first byte of the tail in the page.
+ ** the page was locked and this part of the page was up to date when
+ ** indirect2direct was called, so we know the bytes are still valid
+ */
+ tail = tail + (pos & (PAGE_CACHE_SIZE - 1));
+
+ PATH_LAST_POSITION(path)++;
+
+ key = *item_key;
+ set_cpu_key_k_type(&key, TYPE_DIRECT);
+ key.key_length = 4;
+ /* Insert tail as new direct item in the tree */
+ if (reiserfs_insert_item(th, path, &key, &s_ih, inode,
+ tail ? tail : NULL) < 0) {
+ /* No disk memory. So we can not convert last unformatted node
+ to the direct item. In this case we used to adjust
+ indirect items's ih_free_space. Now ih_free_space is not
+ used, it would be ideal to write zeros to corresponding
+ unformatted node. For now i_size is considered as guard for
+ going out of file size */
+ kunmap(page);
+ return block_size - round_tail_len;
+ }
+ kunmap(page);
+
+ /* make sure to get the i_blocks changes from reiserfs_insert_item */
+ reiserfs_update_sd(th, inode);
+
+ // note: we have now the same as in above direct2indirect
+ // conversion: there are two keys which have matching first three
+ // key components. They only differ by the fouhth one.
+
+ /* We have inserted new direct item and must remove last
+ unformatted node. */
+ *mode = M_CUT;
+
+ /* we store position of first direct item in the in-core inode */
+ /* mark_file_with_tail (inode, pos1 + 1); */
+ REISERFS_I(inode)->i_first_direct_byte = pos1 + 1;
+
+ return block_size - round_tail_len;
+}