patch-2.4.1 linux/fs/reiserfs/inode.c

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diff -u --recursive --new-file v2.4.0/linux/fs/reiserfs/inode.c linux/fs/reiserfs/inode.c
@@ -0,0 +1,1881 @@
+/*
+ * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
+ */
+#ifdef __KERNEL__
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/reiserfs_fs.h>
+#include <linux/locks.h>
+#include <linux/smp_lock.h>
+#include <asm/uaccess.h>
+
+#else
+
+#include "nokernel.h"
+
+#endif
+
+/* args for the create parameter of reiserfs_get_block */
+#define GET_BLOCK_NO_CREATE 0 /* don't create new blocks or convert tails */
+#define GET_BLOCK_CREATE 1    /* add anything you need to find block */
+#define GET_BLOCK_NO_HOLE 2   /* return -ENOENT for file holes */
+#define GET_BLOCK_READ_DIRECT 4  /* read the tail if indirect item not found */
+
+//
+// initially this function was derived from minix or ext2's analog and
+// evolved as the prototype did
+//
+void reiserfs_delete_inode (struct inode * inode)
+{
+    int jbegin_count = JOURNAL_PER_BALANCE_CNT * 2; 
+    int windex ;
+    struct reiserfs_transaction_handle th ;
+
+  
+    lock_kernel() ; 
+
+    /* The = 0 happens when we abort creating a new inode for some reason like lack of space.. */
+    if (INODE_PKEY(inode)->k_objectid != 0) { /* also handles bad_inode case */
+	down (&inode->i_sem); 
+
+	journal_begin(&th, inode->i_sb, jbegin_count) ;
+	windex = push_journal_writer("delete_inode") ;
+
+	reiserfs_delete_object (&th, inode);
+	reiserfs_remove_page_from_flush_list(&th, inode) ;
+	pop_journal_writer(windex) ;
+	reiserfs_release_objectid (&th, inode->i_ino);
+
+	journal_end(&th, inode->i_sb, jbegin_count) ;
+
+	up (&inode->i_sem); 
+    } else {
+	/* no object items are in the tree */
+	;
+    }
+    clear_inode (inode); /* note this must go after the journal_end to prevent deadlock */
+    unlock_kernel() ;
+}
+
+static void _make_cpu_key (struct cpu_key * key, int version, __u32 dirid, __u32 objectid, 
+			   loff_t offset, int type, int length)
+{
+  key->version = version;
+
+  key->on_disk_key.k_dir_id = dirid;
+  key->on_disk_key.k_objectid = objectid;
+  set_cpu_key_k_offset (key, offset);
+  set_cpu_key_k_type (key, type);  
+  key->key_length = length;
+}
+
+
+/* take base of inode_key (it comes from inode always) (dirid, objectid) and version from an inode, set
+   offset and type of key */
+void make_cpu_key (struct cpu_key * key, const struct inode * inode, loff_t offset,
+		   int type, int length)
+{
+  _make_cpu_key (key, inode_items_version (inode), le32_to_cpu (INODE_PKEY (inode)->k_dir_id),
+					  le32_to_cpu (INODE_PKEY (inode)->k_objectid), 
+		 offset, type, length);
+}
+
+
+//
+// when key is 0, do not set version and short key
+//
+inline void make_le_item_head (struct item_head * ih, struct cpu_key * key, int version,
+			       loff_t offset, int type, int length, int entry_count/*or ih_free_space*/)
+{
+    if (key) {
+	ih->ih_key.k_dir_id = cpu_to_le32 (key->on_disk_key.k_dir_id);
+	ih->ih_key.k_objectid = cpu_to_le32 (key->on_disk_key.k_objectid);
+    }
+    ih->ih_version = cpu_to_le16 (version);
+    set_le_ih_k_offset (ih, offset);
+    set_le_ih_k_type (ih, type);
+    ih->ih_item_len = cpu_to_le16 (length);
+    /*    set_ih_free_space (ih, 0);*/
+    // for directory items it is entry count, for directs and stat
+    // datas - 0xffff, for indirects - 0
+    ih->u.ih_entry_count = cpu_to_le16 (entry_count);
+}
+
+
+//
+// FIXME: we might cache recently accessed indirect item (or at least
+// first 15 pointers just like ext2 does
+
+// Ugh.  Not too eager for that....
+//  I cut the code until such time as I see a convincing argument (benchmark).
+// I don't want a bloated inode struct..., and I don't like code complexity....
+
+/* cutting the code is fine, since it really isn't in use yet and is easy
+** to add back in.  But, Vladimir has a really good idea here.  Think
+** about what happens for reading a file.  For each page,
+** The VFS layer calls reiserfs_readpage, who searches the tree to find
+** an indirect item.  This indirect item has X number of pointers, where
+** X is a big number if we've done the block allocation right.  But,
+** we only use one or two of these pointers during each call to readpage,
+** needlessly researching again later on.
+**
+** The size of the cache could be dynamic based on the size of the file.
+**
+** I'd also like to see us cache the location the stat data item, since
+** we are needlessly researching for that frequently.
+**
+** --chris
+*/
+
+/* people who call journal_begin with a page locked must call this
+** BEFORE calling journal_begin
+*/
+static int prevent_flush_page_lock(struct page *page, 
+				   struct inode *inode) {
+  struct reiserfs_page_list *pl ;
+  struct super_block *s = inode->i_sb ;
+  /* we don't care if the inode has a stale pointer from an old
+  ** transaction
+  */
+  if(!page || inode->u.reiserfs_i.i_conversion_trans_id != SB_JOURNAL(s)->j_trans_id) {
+    return 0 ;
+  }
+  pl = inode->u.reiserfs_i.i_converted_page ;
+  if (pl && pl->page == page) {
+    pl->do_not_lock = 1 ;
+  }
+  /* this last part is really important.  The address space operations have
+  ** the page locked before they call the journal functions.  So it is possible
+  ** for one process to be waiting in flush_pages_before_commit for a 
+  ** page, then for the process with the page locked to call journal_begin.
+  **
+  ** We'll deadlock because the process flushing pages will never notice
+  ** the process with the page locked has called prevent_flush_page_lock.
+  ** So, we wake up the page waiters, even though the page is still locked.
+  ** The process waiting in flush_pages_before_commit must check the
+  ** pl->do_not_lock flag, and stop trying to lock the page.
+  */
+  wake_up(&page->wait) ;
+  return 0 ;
+ 
+}
+/* people who call journal_end with a page locked must call this
+** AFTER calling journal_end
+*/
+static int allow_flush_page_lock(struct page *page, 
+				   struct inode *inode) {
+
+  struct reiserfs_page_list *pl ;
+  struct super_block *s = inode->i_sb ;
+  /* we don't care if the inode has a stale pointer from an old
+  ** transaction
+  */
+  if(!page || inode->u.reiserfs_i.i_conversion_trans_id != SB_JOURNAL(s)->j_trans_id) {
+    return 0 ;
+  }
+  pl = inode->u.reiserfs_i.i_converted_page ;
+  if (pl && pl->page == page) {
+    pl->do_not_lock = 0 ;
+  }
+  return 0 ;
+ 
+}
+
+/* If this page has a file tail in it, and
+** it was read in by get_block_create_0, the page data is valid,
+** but tail is still sitting in a direct item, and we can't write to
+** it.  So, look through this page, and check all the mapped buffers
+** to make sure they have valid block numbers.  Any that don't need
+** to be unmapped, so that block_prepare_write will correctly call
+** reiserfs_get_block to convert the tail into an unformatted node
+*/
+static inline void fix_tail_page_for_writing(struct page *page) {
+    struct buffer_head *head, *next, *bh ;
+
+    if (page && page->buffers) {
+	head = page->buffers ;
+	bh = head ;
+	do {
+	    next = bh->b_this_page ;
+	    if (buffer_mapped(bh) && bh->b_blocknr == 0) {
+	        reiserfs_unmap_buffer(bh) ;
+	    }
+	    bh = next ;
+	} while (bh != head) ;
+    }
+}
+
+
+
+
+/* we need to allocate a block for new unformatted node.  Try to figure out
+   what point in bitmap reiserfs_new_blocknrs should start from. */
+static b_blocknr_t find_tag (struct buffer_head * bh, struct item_head * ih,
+			     __u32 * item, int pos_in_item)
+{
+  if (!is_indirect_le_ih (ih))
+	 /* something more complicated could be here */
+	 return bh->b_blocknr;
+
+  /* for indirect item: go to left and look for the first non-hole entry in
+	  the indirect item */
+  if (pos_in_item == I_UNFM_NUM (ih))
+	 pos_in_item --;
+  while (pos_in_item >= 0) {
+	 if (item [pos_in_item])
+		return item [pos_in_item];
+	 pos_in_item --;
+  }
+  return bh->b_blocknr;
+}
+
+
+/* reiserfs_get_block does not need to allocate a block only if it has been
+   done already or non-hole position has been found in the indirect item */
+static inline int allocation_needed (int retval, b_blocknr_t allocated, 
+				     struct item_head * ih,
+				     __u32 * item, int pos_in_item)
+{
+  if (allocated)
+	 return 0;
+  if (retval == POSITION_FOUND && is_indirect_le_ih (ih) && item[pos_in_item])
+	 return 0;
+  return 1;
+}
+
+static inline int indirect_item_found (int retval, struct item_head * ih)
+{
+  return (retval == POSITION_FOUND) && is_indirect_le_ih (ih);
+}
+
+
+static inline void set_block_dev_mapped (struct buffer_head * bh, 
+					 b_blocknr_t block, struct inode * inode)
+{
+  bh->b_dev = inode->i_dev;
+  bh->b_blocknr = block;
+  bh->b_state |= (1UL << BH_Mapped);
+}
+
+
+//
+// files which were created in the earlier version can not be longer,
+// than 2 gb
+//
+int file_capable (struct inode * inode, long block)
+{
+    if (inode_items_version (inode) != ITEM_VERSION_1 || // it is new file.
+	block < (1 << (31 - inode->i_sb->s_blocksize_bits))) // old file, but 'block' is inside of 2gb
+	return 1;
+
+    return 0;
+}
+
+/*static*/ void restart_transaction(struct reiserfs_transaction_handle *th,
+				struct inode *inode, struct path *path) {
+  struct super_block *s = th->t_super ;
+  int len = th->t_blocks_allocated ;
+
+  pathrelse(path) ;
+  reiserfs_update_sd(th, inode) ;
+  journal_end(th, s, len) ;
+  journal_begin(th, s, len) ;
+}
+
+// it is called by get_block when create == 0. Returns block number
+// for 'block'-th logical block of file. When it hits direct item it
+// returns 0 (being called from bmap) or read direct item into piece
+// of page (bh_result)
+
+// Please improve the english/clarity in the comment above, as it is
+// hard to understand.
+
+static int _get_block_create_0 (struct inode * inode, long block,
+				 struct buffer_head * bh_result,
+				 int args)
+{
+    INITIALIZE_PATH (path);
+    struct cpu_key key;
+    struct buffer_head * bh;
+    struct item_head * ih, tmp_ih;
+    int fs_gen ;
+    int blocknr;
+    char * p = NULL;
+    int chars;
+    int ret ;
+    unsigned long offset ;
+
+    // prepare the key to look for the 'block'-th block of file
+    make_cpu_key (&key, inode,
+		  (loff_t)block * inode->i_sb->s_blocksize + 1, TYPE_ANY, 3);
+
+research:
+    if (search_for_position_by_key (inode->i_sb, &key, &path) != POSITION_FOUND) {
+	pathrelse (&path);
+        if (p)
+            kunmap(bh_result->b_page) ;
+	if ((args & GET_BLOCK_NO_HOLE)) {
+	    return -ENOENT ;
+	}
+        return 0 ;
+    }
+    
+    //
+    bh = get_bh (&path);
+    ih = get_ih (&path);
+    if (is_indirect_le_ih (ih)) {
+	__u32 * ind_item = (__u32 *)B_I_PITEM (bh, ih);
+	
+	/* FIXME: here we could cache indirect item or part of it in
+	   the inode to avoid search_by_key in case of subsequent
+	   access to file */
+	blocknr = le32_to_cpu (ind_item [path.pos_in_item]);
+	ret = 0 ;
+	if (blocknr) {
+	    bh_result->b_dev = inode->i_dev;
+	    bh_result->b_blocknr = blocknr;
+	    bh_result->b_state |= (1UL << BH_Mapped);
+	} else if ((args & GET_BLOCK_NO_HOLE)) {
+	    ret = -ENOENT ;
+	}
+	pathrelse (&path);
+        if (p)
+            kunmap(bh_result->b_page) ;
+	return ret ;
+    }
+
+    // requested data are in direct item(s)
+    if (!(args & GET_BLOCK_READ_DIRECT)) {
+	// we are called by bmap. FIXME: we can not map block of file
+	// when it is stored in direct item(s)
+	pathrelse (&path);	
+        if (p)
+            kunmap(bh_result->b_page) ;
+	return -ENOENT;
+    }
+
+    // read file tail into part of page
+    offset = (cpu_key_k_offset(&key) - 1) & (PAGE_CACHE_SIZE - 1) ;
+    fs_gen = get_generation(inode->i_sb) ;
+    copy_item_head (&tmp_ih, ih);
+
+    /* we only want to kmap if we are reading the tail into the page.
+    ** this is not the common case, so we don't kmap until we are
+    ** sure we need to.  But, this means the item might move if
+    ** kmap schedules
+    */
+    p = (char *)kmap(bh_result->b_page) ;
+    if (fs_changed (fs_gen, inode->i_sb) && item_moved (&tmp_ih, &path)) {
+        goto research;
+    }
+    p += offset ;
+    memset (p, 0, inode->i_sb->s_blocksize);
+    do {
+	if (!is_direct_le_ih (ih)) {
+	    BUG ();
+        }
+	chars = le16_to_cpu (ih->ih_item_len) - path.pos_in_item;
+	memcpy (p, B_I_PITEM (bh, ih) + path.pos_in_item, chars);
+	p += chars;
+
+	if (PATH_LAST_POSITION (&path) != (B_NR_ITEMS (bh) - 1))
+	    // we done, if read direct item is not the last item of
+	    // node FIXME: we could try to check right delimiting key
+	    // to see whether direct item continues in the right
+	    // neighbor or rely on i_size
+	    break;
+
+	// update key to look for the next piece
+	set_cpu_key_k_offset (&key, cpu_key_k_offset (&key) + chars);
+	if (search_for_position_by_key (inode->i_sb, &key, &path) != POSITION_FOUND)
+	    // we read something from tail, even if now we got IO_ERROR
+	    break;
+	bh = get_bh (&path);
+	ih = get_ih (&path);
+    } while (1);
+
+    pathrelse (&path);
+    
+    // FIXME: b_blocknr == 0 here. but b_data contains correct data
+    // from tail. ll_rw_block will skip uptodate buffers
+    bh_result->b_blocknr = 0 ;
+    bh_result->b_dev = inode->i_dev;
+    mark_buffer_uptodate (bh_result, 1);
+    bh_result->b_state |= (1UL << BH_Mapped);
+    kunmap(bh_result->b_page) ;
+
+    return 0;
+}
+
+
+// this is called to create file map. So, _get_block_create_0 will not
+// read direct item
+int reiserfs_bmap (struct inode * inode, long block,
+		   struct buffer_head * bh_result, int create)
+{
+    if (!file_capable (inode, block))
+	return -EFBIG;
+
+    lock_kernel() ;
+    /* do not read the direct item */
+    _get_block_create_0 (inode, block, bh_result, 0) ;
+    unlock_kernel() ;
+    return 0;
+}
+
+/* special version of get_block that is only used by grab_tail_page right
+** now.  It is sent to block_prepare_write, and when you try to get a
+** block past the end of the file (or a block from a hole) it returns
+** -ENOENT instead of a valid buffer.  block_prepare_write expects to
+** be able to do i/o on the buffers returned, unless an error value
+** is also returned.
+** 
+** So, this allows block_prepare_write to be used for reading a single block
+** in a page.  Where it does not produce a valid page for holes, or past the
+** end of the file.  This turns out to be exactly what we need for reading
+** tails for conversion.
+**
+** The point of the wrapper is forcing a certain value for create, even
+** though the VFS layer is calling this function with create==1.  If you 
+** don't want to send create == GET_BLOCK_NO_HOLE to reiserfs_get_block, 
+** don't use this function.
+*/
+static int reiserfs_get_block_create_0 (struct inode * inode, long block,
+			struct buffer_head * bh_result, int create) {
+    return reiserfs_get_block(inode, block, bh_result, GET_BLOCK_NO_HOLE) ;
+}
+
+/*
+** helper function for when reiserfs_get_block is called for a hole
+** but the file tail is still in a direct item
+** bh_result is the buffer head for the hole
+** tail_offset is the offset of the start of the tail in the file
+**
+** This calls prepare_write, which will start a new transaction
+** you should not be in a transaction, or have any paths held when you
+** call this.
+*/
+static int convert_tail_for_hole(struct inode *inode, 
+                                 struct buffer_head *bh_result,
+				 loff_t tail_offset) {
+    unsigned long index ;
+    unsigned long tail_end ; 
+    unsigned long tail_start ;
+    struct page * tail_page ;
+    struct page * hole_page = bh_result->b_page ;
+    int retval = 0 ;
+
+    if ((tail_offset & (bh_result->b_size - 1)) != 1) 
+        return -EIO ;
+
+    /* always try to read until the end of the block */
+    tail_start = tail_offset & (PAGE_CACHE_SIZE - 1) ;
+    tail_end = (tail_start | (bh_result->b_size - 1)) + 1 ;
+
+    index = tail_offset >> PAGE_CACHE_SHIFT ;
+    if (index != hole_page->index) {
+	tail_page = grab_cache_page(inode->i_mapping, index) ;
+	retval = PTR_ERR(tail_page) ;
+	if (IS_ERR(tail_page)) {
+	    goto out ;
+	}
+    } else {
+        tail_page = hole_page ;
+    }
+
+    /* we don't have to make sure the conversion did not happen while
+    ** we were locking the page because anyone that could convert
+    ** must first take i_sem.
+    **
+    ** We must fix the tail page for writing because it might have buffers
+    ** that are mapped, but have a block number of 0.  This indicates tail
+    ** data that has been read directly into the page, and block_prepare_write
+    ** won't trigger a get_block in this case.
+    */
+    fix_tail_page_for_writing(tail_page) ;
+    retval = block_prepare_write(tail_page, tail_start, tail_end, 
+                                 reiserfs_get_block) ; 
+    if (retval)
+        goto unlock ;
+
+    /* tail conversion might change the data in the page */
+    flush_dcache_page(tail_page) ;
+
+    retval = generic_commit_write(NULL, tail_page, tail_start, tail_end) ;
+
+unlock:
+    if (tail_page != hole_page) {
+        UnlockPage(tail_page) ;
+	page_cache_release(tail_page) ;
+    }
+out:
+    return retval ;
+}
+
+//
+// initially this function was derived from ext2's analog and evolved
+// as the prototype did.  You'll need to look at the ext2 version to
+// determine which parts are derivative, if any, understanding that
+// there are only so many ways to code to a given interface.
+//
+int reiserfs_get_block (struct inode * inode, long block,
+			struct buffer_head * bh_result, int create)
+{
+    int repeat, retval;
+    unsigned long tag;
+    b_blocknr_t allocated_block_nr = 0;// b_blocknr_t is unsigned long
+    INITIALIZE_PATH(path);
+    int pos_in_item;
+    struct cpu_key key;
+    struct buffer_head * bh, * unbh = 0;
+    struct item_head * ih, tmp_ih;
+    __u32 * item;
+    int done;
+    int fs_gen;
+    int windex ;
+    struct reiserfs_transaction_handle th ;
+    int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3 ;
+    int version;
+    int transaction_started = 0 ;
+    loff_t new_offset = (block << inode->i_sb->s_blocksize_bits) + 1 ;
+
+				/* bad.... */
+    lock_kernel() ;
+    th.t_trans_id = 0 ;
+    version = inode_items_version (inode);
+
+    if (!file_capable (inode, block)) {
+	unlock_kernel() ;
+	return -EFBIG;
+    }
+
+    /* if !create, we aren't changing the FS, so we don't need to
+    ** log anything, so we don't need to start a transaction
+    */
+    if (!(create & GET_BLOCK_CREATE)) {
+	int ret ;
+	/* find number of block-th logical block of the file */
+	ret = _get_block_create_0 (inode, block, bh_result, 
+	                           create | GET_BLOCK_READ_DIRECT) ;
+	unlock_kernel() ;
+	return ret;
+    }
+
+    if (block < 0) {
+	unlock_kernel();
+	return -EIO;
+    }
+
+    prevent_flush_page_lock(bh_result->b_page, inode) ;
+    inode->u.reiserfs_i.i_pack_on_close = 1 ;
+
+    windex = push_journal_writer("reiserfs_get_block") ;
+  
+    /* set the key of the first byte in the 'block'-th block of file */
+    make_cpu_key (&key, inode,
+		  (loff_t)block * inode->i_sb->s_blocksize + 1, // k_offset
+		  TYPE_ANY, 3/*key length*/);
+    if ((new_offset + inode->i_sb->s_blocksize) >= inode->i_size) {
+	journal_begin(&th, inode->i_sb, jbegin_count) ;
+	transaction_started = 1 ;
+    }
+ research:
+
+    retval = search_for_position_by_key (inode->i_sb, &key, &path);
+    if (retval == IO_ERROR) {
+	retval = -EIO;
+	goto failure;
+    }
+	
+    bh = get_bh (&path);
+    ih = get_ih (&path);
+    item = get_item (&path);
+    pos_in_item = path.pos_in_item;
+
+    fs_gen = get_generation (inode->i_sb);
+    copy_item_head (&tmp_ih, ih);
+
+    if (allocation_needed (retval, allocated_block_nr, ih, item, pos_in_item)) {
+	/* we have to allocate block for the unformatted node */
+	tag = find_tag (bh, ih, item, pos_in_item);
+	if (!transaction_started) {
+	    pathrelse(&path) ;
+	    journal_begin(&th, inode->i_sb, jbegin_count) ;
+	    transaction_started = 1 ;
+	    goto research ;
+	}
+
+#ifdef REISERFS_PREALLOCATE
+	repeat = reiserfs_new_unf_blocknrs2 (&th, inode, &allocated_block_nr, tag);
+#else
+	repeat = reiserfs_new_unf_blocknrs (&th, &allocated_block_nr, tag);
+#endif
+
+	if (repeat == NO_DISK_SPACE) {
+	    /* restart the transaction to give the journal a chance to free
+	    ** some blocks.  releases the path, so we have to go back to
+	    ** research if we succeed on the second try
+	    */
+	    restart_transaction(&th, inode, &path) ; 
+#ifdef REISERFS_PREALLOCATE
+	    repeat = reiserfs_new_unf_blocknrs2 (&th, inode, &allocated_block_nr, tag);
+#else
+	    repeat = reiserfs_new_unf_blocknrs (&th, &allocated_block_nr, tag);
+#endif
+
+	    if (repeat != NO_DISK_SPACE) {
+		goto research ;
+	    }
+	    retval = -ENOSPC;
+	    goto failure;
+	}
+
+	if (fs_changed (fs_gen, inode->i_sb) && item_moved (&tmp_ih, &path)) {
+	    goto research;
+	}
+    }
+
+    if (indirect_item_found (retval, ih)) {
+	/* 'block'-th block is in the file already (there is
+	   corresponding cell in some indirect item). But it may be
+	   zero unformatted node pointer (hole) */
+	if (!item[pos_in_item]) {
+	    /* use allocated block to plug the hole */
+	    reiserfs_prepare_for_journal(inode->i_sb, bh, 1) ;
+	    if (fs_changed (fs_gen, inode->i_sb) && item_moved (&tmp_ih, &path)) {
+		reiserfs_restore_prepared_buffer(inode->i_sb, bh) ;
+		goto research;
+	    }
+	    bh_result->b_state |= (1UL << BH_New);
+	    item[pos_in_item] = cpu_to_le32 (allocated_block_nr);
+	    journal_mark_dirty (&th, inode->i_sb, bh);
+	    inode->i_blocks += (inode->i_sb->s_blocksize / 512) ;
+	    reiserfs_update_sd(&th, inode) ;
+	}
+	set_block_dev_mapped(bh_result, le32_to_cpu (item[pos_in_item]), inode);
+	pathrelse (&path);
+#ifdef REISERFS_CHECK
+	pop_journal_writer(windex) ;
+#endif /* REISERFS_CHECK */
+	if (transaction_started)
+	    journal_end(&th, inode->i_sb, jbegin_count) ;
+
+	allow_flush_page_lock(bh_result->b_page, inode) ;
+	unlock_kernel() ;
+	 
+	/* the item was found, so new blocks were not added to the file
+	** there is no need to make sure the inode is updated with this 
+	** transaction
+	*/
+	return 0;
+    }
+
+    if (!transaction_started) {
+	/* if we don't pathrelse, we could vs-3050 on the buffer if
+	** someone is waiting for it (they can't finish until the buffer
+	** is released, we can start a new transaction until they finish)
+	*/
+	pathrelse(&path) ;
+	journal_begin(&th, inode->i_sb, jbegin_count) ;
+	transaction_started = 1 ;
+	goto research;
+    }
+
+    /* desired position is not found or is in the direct item. We have
+       to append file with holes up to 'block'-th block converting
+       direct items to indirect one if necessary */
+    done = 0;
+    do {
+	if (is_statdata_le_ih (ih)) {
+	    __u32 unp = 0;
+	    struct cpu_key tmp_key;
+
+	    /* indirect item has to be inserted */
+	    make_le_item_head (&tmp_ih, &key, version, 1, TYPE_INDIRECT, 
+			       UNFM_P_SIZE, 0/* free_space */);
+
+	    if (cpu_key_k_offset (&key) == 1) {
+		/* we are going to add 'block'-th block to the file. Use
+		   allocated block for that */
+		unp = cpu_to_le32 (allocated_block_nr);
+		set_block_dev_mapped (bh_result, allocated_block_nr, inode);
+		bh_result->b_state |= (1UL << BH_New);
+		done = 1;
+	    }
+	    tmp_key = key; // ;)
+	    set_cpu_key_k_offset (&tmp_key, 1);
+	    PATH_LAST_POSITION(&path) ++;
+
+	    retval = reiserfs_insert_item (&th, &path, &tmp_key, &tmp_ih, (char *)&unp);
+	    if (retval) {
+		reiserfs_free_block (&th, allocated_block_nr);
+
+#ifdef REISERFS_PREALLOCATE
+		reiserfs_discard_prealloc (&th, inode); 
+#endif
+		goto failure; // retval == -ENOSPC or -EIO or -EEXIST
+	    }
+	    if (unp)
+		inode->i_blocks += inode->i_sb->s_blocksize / 512;
+	    //mark_tail_converted (inode);
+	} else if (is_direct_le_ih (ih)) {
+	    /* direct item has to be converted */
+	    loff_t tail_offset;
+
+	    tail_offset = ((le_ih_k_offset (ih) - 1) & ~(inode->i_sb->s_blocksize - 1)) + 1;
+	    if (tail_offset == cpu_key_k_offset (&key)) {
+		/* direct item we just found fits into block we have
+                   to map. Convert it into unformatted node: use
+                   bh_result for the conversion */
+		set_block_dev_mapped (bh_result, allocated_block_nr, inode);
+		unbh = bh_result;
+		done = 1;
+	    } else {
+		/* we have to padd file tail stored in direct item(s)
+		   up to block size and convert it to unformatted
+		   node. FIXME: this should also get into page cache */
+
+		pathrelse(&path) ;
+		journal_end(&th, inode->i_sb, jbegin_count) ;
+		transaction_started = 0 ;
+
+		retval = convert_tail_for_hole(inode, bh_result, tail_offset) ;
+		if (retval) {
+		    printk("clm-6004: convert tail failed inode %lu, error %d\n", inode->i_ino, retval) ;
+		    if (allocated_block_nr)
+			reiserfs_free_block (&th, allocated_block_nr);
+		    goto failure ;
+		}
+		goto research ;
+	    }
+	    retval = direct2indirect (&th, inode, &path, unbh, tail_offset);
+	    /* it is important the mark_buffer_uptodate is done after
+	    ** the direct2indirect.  The buffer might contain valid
+	    ** data newer than the data on disk (read by readpage, changed,
+	    ** and then sent here by writepage).  direct2indirect needs
+	    ** to know if unbh was already up to date, so it can decide
+	    ** if the data in unbh needs to be replaced with data from
+	    ** the disk
+	    */
+	    mark_buffer_uptodate (unbh, 1);
+	    if (retval) {
+		reiserfs_free_block (&th, allocated_block_nr);
+
+#ifdef REISERFS_PREALLOCATE
+		reiserfs_discard_prealloc (&th, inode); 
+#endif
+		goto failure;
+	    }
+	    /* we've converted the tail, so we must 
+	    ** flush unbh before the transaction commits
+	    */
+	    reiserfs_add_page_to_flush_list(&th, inode, unbh) ;
+		  
+	    //inode->i_blocks += inode->i_sb->s_blocksize / 512;
+	    //mark_tail_converted (inode);
+	} else {
+	    /* append indirect item with holes if needed, when appending
+	       pointer to 'block'-th block use block, which is already
+	       allocated */
+	    struct cpu_key tmp_key;
+	    struct unfm_nodeinfo un = {0, 0};
+
+#ifdef CONFIG_REISERFS_CHECK
+	    if (pos_in_item != le16_to_cpu (ih->ih_item_len) / UNFM_P_SIZE)
+		reiserfs_panic (inode->i_sb, "vs-: reiserfs_get_block: "
+				"invalid position for append");
+#endif
+	    /* indirect item has to be appended, set up key of that position */
+	    make_cpu_key (&tmp_key, inode,
+			  le_key_k_offset (version, &(ih->ih_key)) + op_bytes_number (ih, inode->i_sb->s_blocksize),
+			  //pos_in_item * inode->i_sb->s_blocksize,
+			  TYPE_INDIRECT, 3);// key type is unimportant
+		  
+	    if (cpu_key_k_offset (&tmp_key) == cpu_key_k_offset (&key)) {
+		/* we are going to add target block to the file. Use allocated
+		   block for that */
+		un.unfm_nodenum = cpu_to_le32 (allocated_block_nr);
+		set_block_dev_mapped (bh_result, allocated_block_nr, inode);
+		bh_result->b_state |= (1UL << BH_New);
+		done = 1;
+	    } else {
+		/* paste hole to the indirect item */
+	    }
+	    retval = reiserfs_paste_into_item (&th, &path, &tmp_key, (char *)&un, UNFM_P_SIZE);
+	    if (retval) {
+		reiserfs_free_block (&th, allocated_block_nr);
+
+#ifdef REISERFS_PREALLOCATE
+		reiserfs_discard_prealloc (&th, inode); 
+#endif
+		goto failure;
+	    }
+	    if (un.unfm_nodenum)
+		inode->i_blocks += inode->i_sb->s_blocksize / 512;
+	    //mark_tail_converted (inode);
+	}
+		
+	if (done == 1)
+	    break;
+	 
+	/* this loop could log more blocks than we had originally asked
+	** for.  So, we have to allow the transaction to end if it is
+	** too big or too full.  Update the inode so things are 
+	** consistent if we crash before the function returns
+	**
+	** release the path so that anybody waiting on the path before
+	** ending their transaction will be able to continue.
+	*/
+	if (journal_transaction_should_end(&th, th.t_blocks_allocated)) {
+	  restart_transaction(&th, inode, &path) ; 
+	}
+	/* inserting indirect pointers for a hole can take a 
+	** long time.  reschedule if needed
+	*/
+	if (current->need_resched)
+	    schedule() ;
+
+	retval = search_for_position_by_key (inode->i_sb, &key, &path);
+	if (retval == IO_ERROR) {
+	    retval = -EIO;
+	    goto failure;
+	}
+	if (retval == POSITION_FOUND) {
+	    reiserfs_warning ("vs-: reiserfs_get_block: "
+			      "%k should not be found", &key);
+	    retval = -EEXIST;
+	    pathrelse(&path) ;
+	    goto failure;
+	}
+	bh = get_bh (&path);
+	ih = get_ih (&path);
+	item = get_item (&path);
+	pos_in_item = path.pos_in_item;
+    } while (1);
+
+
+    retval = 0;
+    reiserfs_check_path(&path) ;
+
+ failure:
+    if (transaction_started) {
+      reiserfs_update_sd(&th, inode) ;
+      journal_end(&th, inode->i_sb, jbegin_count) ;
+    }
+    pop_journal_writer(windex) ;
+    allow_flush_page_lock(bh_result->b_page, inode) ;
+    unlock_kernel() ;
+    reiserfs_check_path(&path) ;
+    return retval;
+}
+
+
+//
+// BAD: new directories have stat data of new type and all other items
+// of old type. Version stored in the inode says about body items, so
+// in update_stat_data we can not rely on inode, but have to check
+// item version directly
+//
+
+// called by read_inode
+static void init_inode (struct inode * inode, struct path * path)
+{
+    struct buffer_head * bh;
+    struct item_head * ih;
+    __u32 rdev;
+    //int version = ITEM_VERSION_1;
+
+    bh = PATH_PLAST_BUFFER (path);
+    ih = PATH_PITEM_HEAD (path);
+
+
+    copy_key (INODE_PKEY (inode), &(ih->ih_key));
+    inode->i_generation = INODE_PKEY (inode)->k_dir_id;
+    inode->i_blksize = PAGE_SIZE;
+
+    if (stat_data_v1 (ih)) {
+	struct stat_data_v1 * sd = (struct stat_data_v1 *)B_I_PITEM (bh, ih);
+	unsigned long blocks;
+
+	inode_items_version (inode) = ITEM_VERSION_1;
+	inode->i_mode = le16_to_cpu (sd->sd_mode);
+	inode->i_nlink = le16_to_cpu (sd->sd_nlink);
+	inode->i_uid = le16_to_cpu (sd->sd_uid);
+	inode->i_gid = le16_to_cpu (sd->sd_gid);
+	inode->i_size = le32_to_cpu (sd->sd_size);
+	inode->i_atime = le32_to_cpu (sd->sd_atime);
+	inode->i_mtime = le32_to_cpu (sd->sd_mtime);
+	inode->i_ctime = le32_to_cpu (sd->sd_ctime);
+
+	inode->i_blocks = le32_to_cpu (sd->u.sd_blocks);
+	blocks = (inode->i_size + 511) >> 9;
+	blocks = _ROUND_UP (blocks, inode->i_blksize >> 9);
+	if (inode->i_blocks > blocks) {
+	    // there was a bug in <=3.5.23 when i_blocks could take negative
+	    // values. Starting from 3.5.17 this value could even be stored in
+	    // stat data. For such files we set i_blocks based on file
+	    // size. Just 2 notes: this can be wrong for sparce files. On-disk value will be
+	    // only updated if file's inode will ever change
+	    inode->i_blocks = blocks;
+	}
+
+	rdev = le32_to_cpu (sd->u.sd_rdev);
+	inode->u.reiserfs_i.i_first_direct_byte = le32_to_cpu (sd->sd_first_direct_byte);
+    } else {
+	// new stat data found, but object may have old items
+	// (directories and symlinks)
+	struct stat_data * sd = (struct stat_data *)B_I_PITEM (bh, ih);
+
+	/* both old and new directories have old keys */
+	//version = (S_ISDIR (sd->sd_mode) ? ITEM_VERSION_1 : ITEM_VERSION_2);
+	if (S_ISDIR (sd->sd_mode) || S_ISLNK (sd->sd_mode))
+	    inode_items_version (inode) = ITEM_VERSION_1;
+	else
+	    inode_items_version (inode) = ITEM_VERSION_2;
+	inode->i_mode = le16_to_cpu (sd->sd_mode);
+	inode->i_nlink = le32_to_cpu (sd->sd_nlink);
+	inode->i_uid = le32_to_cpu (sd->sd_uid);
+	inode->i_size = le64_to_cpu (sd->sd_size);
+	inode->i_gid = le32_to_cpu (sd->sd_gid);
+	inode->i_mtime = le32_to_cpu (sd->sd_mtime);
+	inode->i_atime = le32_to_cpu (sd->sd_atime);
+	inode->i_ctime = le32_to_cpu (sd->sd_ctime);
+	inode->i_blocks = le32_to_cpu (sd->sd_blocks);
+	rdev = le32_to_cpu (sd->u.sd_rdev);
+    }
+
+    /* nopack = 0, by default */
+    inode->u.reiserfs_i.nopack = 0;
+
+    pathrelse (path);
+    if (S_ISREG (inode->i_mode)) {
+	inode->i_op = &reiserfs_file_inode_operations;
+	inode->i_fop = &reiserfs_file_operations;
+	inode->i_mapping->a_ops = &reiserfs_address_space_operations ;
+    } else if (S_ISDIR (inode->i_mode)) {
+	inode->i_op = &reiserfs_dir_inode_operations;
+	inode->i_fop = &reiserfs_dir_operations;
+    } else if (S_ISLNK (inode->i_mode)) {
+	inode->i_op = &page_symlink_inode_operations;
+	inode->i_mapping->a_ops = &reiserfs_address_space_operations;
+    } else {
+	inode->i_blocks = 0;
+	init_special_inode(inode, inode->i_mode, rdev) ;
+    }
+}
+
+
+// update new stat data with inode fields
+static void inode2sd (void * sd, struct inode * inode)
+{
+    struct stat_data * sd_v2 = (struct stat_data *)sd;
+
+    sd_v2->sd_mode = cpu_to_le16 (inode->i_mode);
+    sd_v2->sd_nlink = cpu_to_le16 (inode->i_nlink);
+    sd_v2->sd_uid = cpu_to_le32 (inode->i_uid);
+    sd_v2->sd_size = cpu_to_le64 (inode->i_size);
+    sd_v2->sd_gid = cpu_to_le32 (inode->i_gid);
+    sd_v2->sd_mtime = cpu_to_le32 (inode->i_mtime);
+    sd_v2->sd_atime = cpu_to_le32 (inode->i_atime);
+    sd_v2->sd_ctime = cpu_to_le32 (inode->i_ctime);
+    sd_v2->sd_blocks = cpu_to_le32 (inode->i_blocks);
+    if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+	sd_v2->u.sd_rdev = cpu_to_le32 (inode->i_rdev);
+}
+
+
+// used to copy inode's fields to old stat data
+static void inode2sd_v1 (void * sd, struct inode * inode)
+{
+    struct stat_data_v1 * sd_v1 = (struct stat_data_v1 *)sd;
+
+    sd_v1->sd_mode = cpu_to_le16 (inode->i_mode);
+    sd_v1->sd_uid = cpu_to_le16 (inode->i_uid);
+    sd_v1->sd_gid = cpu_to_le16 (inode->i_gid);
+    sd_v1->sd_nlink = cpu_to_le16 (inode->i_nlink);
+    sd_v1->sd_size = cpu_to_le32 (inode->i_size);
+    sd_v1->sd_atime = cpu_to_le32 (inode->i_atime);
+    sd_v1->sd_ctime = cpu_to_le32 (inode->i_ctime);
+    sd_v1->sd_mtime = cpu_to_le32 (inode->i_mtime);
+    if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+	sd_v1->u.sd_rdev = cpu_to_le32 (inode->i_rdev);
+    else
+	sd_v1->u.sd_blocks = cpu_to_le32 (inode->i_blocks);
+
+    // Sigh. i_first_direct_byte is back
+    sd_v1->sd_first_direct_byte = cpu_to_le32 (inode->u.reiserfs_i.i_first_direct_byte);
+}
+
+
+/* NOTE, you must prepare the buffer head before sending it here,
+** and then log it after the call
+*/
+static void update_stat_data (struct path * path, struct inode * inode)
+{
+    struct buffer_head * bh;
+    struct item_head * ih;
+  
+    bh = PATH_PLAST_BUFFER (path);
+    ih = PATH_PITEM_HEAD (path);
+
+    if (!is_statdata_le_ih (ih))
+	reiserfs_panic (inode->i_sb, "vs-13065: update_stat_data: key %k, found item %h",
+			INODE_PKEY (inode), ih);
+  
+    if (stat_data_v1 (ih)) {
+	// path points to old stat data
+	inode2sd_v1 (B_I_PITEM (bh, ih), inode);
+    } else {
+	inode2sd (B_I_PITEM (bh, ih), inode);
+    }
+
+    return;
+}
+
+
+void reiserfs_update_sd (struct reiserfs_transaction_handle *th, 
+			 struct inode * inode)
+{
+    struct cpu_key key;
+    INITIALIZE_PATH(path);
+    struct buffer_head *bh ;
+    int fs_gen ;
+    struct item_head *ih, tmp_ih ;
+    int retval;
+
+    make_cpu_key (&key, inode, SD_OFFSET, TYPE_STAT_DATA, 3);//key type is unimportant
+    
+    for(;;) {
+	int pos;
+	/* look for the object's stat data */
+	retval = search_item (inode->i_sb, &key, &path);
+	if (retval == IO_ERROR) {
+	    reiserfs_warning ("vs-13050: reiserfs_update_sd: "
+			      "i/o failure occurred trying to update %K stat data",
+			      &key);
+	    return;
+	}
+	if (retval == ITEM_NOT_FOUND) {
+	    pos = PATH_LAST_POSITION (&path);
+	    pathrelse(&path) ;
+	    if (inode->i_nlink == 0) {
+		/*printk ("vs-13050: reiserfs_update_sd: i_nlink == 0, stat data not found\n");*/
+		return;
+	    }
+	    reiserfs_warning ("vs-13060: reiserfs_update_sd: "
+			      "stat data of object %k (nlink == %d) not found (pos %d)\n", 
+			      INODE_PKEY (inode), inode->i_nlink, pos);
+	    reiserfs_check_path(&path) ;
+	    return;
+	}
+	
+	/* sigh, prepare_for_journal might schedule.  When it schedules the
+	** FS might change.  We have to detect that, and loop back to the
+	** search if the stat data item has moved
+	*/
+	bh = get_bh(&path) ;
+	ih = get_ih(&path) ;
+	copy_item_head (&tmp_ih, ih);
+	fs_gen = get_generation (inode->i_sb);
+	reiserfs_prepare_for_journal(inode->i_sb, bh, 1) ;
+	if (fs_changed (fs_gen, inode->i_sb) && item_moved(&tmp_ih, &path)) {
+	    reiserfs_restore_prepared_buffer(inode->i_sb, bh) ;
+	    continue ;	/* Stat_data item has been moved after scheduling. */
+	}
+	break;
+    }
+    update_stat_data (&path, inode);
+    journal_mark_dirty(th, th->t_super, bh) ; 
+    pathrelse (&path);
+    return;
+}
+
+void reiserfs_read_inode(struct inode *inode) {
+    make_bad_inode(inode) ;
+}
+
+
+//
+// initially this function was derived from minix or ext2's analog and
+// evolved as the prototype did
+//
+
+/* looks for stat data in the tree, and fills up the fields of in-core
+   inode stat data fields */
+void reiserfs_read_inode2 (struct inode * inode, void *p)
+{
+    INITIALIZE_PATH (path_to_sd);
+    struct cpu_key key;
+    struct reiserfs_iget4_args *args = (struct reiserfs_iget4_args *)p ;
+    unsigned long dirino;
+    int retval;
+
+    if (!p) {
+	make_bad_inode(inode) ;
+	return;
+    }
+
+    dirino = args->objectid ;
+
+    /* set version 1, version 2 could be used too, because stat data
+       key is the same in both versions */
+    key.version = ITEM_VERSION_1;
+    key.on_disk_key.k_dir_id = dirino;
+    key.on_disk_key.k_objectid = inode->i_ino;
+    key.on_disk_key.u.k_offset_v1.k_offset = SD_OFFSET;
+    key.on_disk_key.u.k_offset_v1.k_uniqueness = SD_UNIQUENESS;
+
+    /* look for the object's stat data */
+    retval = search_item (inode->i_sb, &key, &path_to_sd);
+    if (retval == IO_ERROR) {
+	reiserfs_warning ("vs-13070: reiserfs_read_inode2: "
+			  "i/o failure occurred trying to find stat data of %K\n",
+			  &key);
+	make_bad_inode(inode) ;
+	return;
+    }
+    if (retval != ITEM_FOUND) {
+	reiserfs_warning ("vs-13042: reiserfs_read_inode2: %K not found\n", &key);
+	pathrelse (&path_to_sd);
+	make_bad_inode(inode) ;
+	return;
+    }
+
+    init_inode (inode, &path_to_sd);
+    reiserfs_check_path(&path_to_sd) ; /* init inode should be relsing */
+
+}
+
+
+struct inode * reiserfs_iget (struct super_block * s, struct cpu_key * key)
+{
+    struct inode * inode;
+    struct reiserfs_iget4_args args ;
+
+    args.objectid = key->on_disk_key.k_dir_id ;
+    inode = iget4 (s, key->on_disk_key.k_objectid, 0, (void *)(&args));
+    if (!inode) 
+      return inode ;
+
+    //    if (comp_short_keys (INODE_PKEY (inode), key)) {
+    if (is_bad_inode (inode)) {
+	reiserfs_warning ("vs-13048: reiserfs_iget: "
+			  "bad_inode. Stat data of (%lu %lu) not found\n",
+			  key->on_disk_key.k_dir_id, key->on_disk_key.k_objectid);
+	iput (inode);
+	inode = 0;
+    }
+    return inode;
+}
+
+
+//
+// initially this function was derived from minix or ext2's analog and
+// evolved as the prototype did
+//
+/* looks for stat data, then copies fields to it, marks the buffer
+   containing stat data as dirty */
+/* reiserfs inodes are never really dirty, since the dirty inode call
+** always logs them.  This call allows the VFS inode marking routines
+** to properly mark inodes for datasync and such, but only actually
+** does something when called for a synchronous update.
+*/
+void reiserfs_write_inode (struct inode * inode, int do_sync) {
+    struct reiserfs_transaction_handle th ;
+    int jbegin_count = 1 ;
+
+    if (inode->i_sb->s_flags & MS_RDONLY) {
+        reiserfs_warning("clm-6005: writing inode %lu on readonly FS\n", 
+	                  inode->i_ino) ;
+        return ;
+    }
+    if (do_sync) {
+	lock_kernel() ;
+	journal_begin(&th, inode->i_sb, jbegin_count) ;
+	reiserfs_update_sd (&th, inode);
+	journal_end_sync(&th, inode->i_sb, jbegin_count) ;
+	unlock_kernel() ;
+    }
+}
+
+void reiserfs_dirty_inode (struct inode * inode) {
+    struct reiserfs_transaction_handle th ;
+
+    if (inode->i_sb->s_flags & MS_RDONLY) {
+        reiserfs_warning("clm-6006: writing inode %lu on readonly FS\n", 
+	                  inode->i_ino) ;
+        return ;
+    }
+    lock_kernel() ;
+    journal_begin(&th, inode->i_sb, 1) ;
+    reiserfs_update_sd (&th, inode);
+    journal_end(&th, inode->i_sb, 1) ;
+    unlock_kernel() ;
+}
+
+
+/* FIXME: no need any more. right? */
+int reiserfs_sync_inode (struct reiserfs_transaction_handle *th, struct inode * inode)
+{
+  int err = 0;
+
+  reiserfs_update_sd (th, inode);
+  return err;
+}
+
+
+/* stat data of new object is inserted already, this inserts the item
+   containing "." and ".." entries */
+static int reiserfs_new_directory (struct reiserfs_transaction_handle *th, 
+				   struct item_head * ih, struct path * path, const struct inode * dir)
+{
+    struct super_block * sb = th->t_super;
+    char empty_dir [EMPTY_DIR_SIZE];
+    char * body = empty_dir;
+    struct cpu_key key;
+    int retval;
+    
+    _make_cpu_key (&key, ITEM_VERSION_1, le32_to_cpu (ih->ih_key.k_dir_id),
+		   le32_to_cpu (ih->ih_key.k_objectid), DOT_OFFSET, TYPE_DIRENTRY, 3/*key length*/);
+    
+    /* compose item head for new item. Directories consist of items of
+       old type (ITEM_VERSION_1). Do not set key (second arg is 0), it
+       is done by reiserfs_new_inode */
+    if (old_format_only (sb)) {
+	make_le_item_head (ih, 0, ITEM_VERSION_1, DOT_OFFSET, TYPE_DIRENTRY, EMPTY_DIR_SIZE_V1, 2);
+	
+	make_empty_dir_item_v1 (body, ih->ih_key.k_dir_id, ih->ih_key.k_objectid,
+				le32_to_cpu (INODE_PKEY (dir)->k_dir_id), 
+				le32_to_cpu (INODE_PKEY (dir)->k_objectid));
+    } else {
+	make_le_item_head (ih, 0, ITEM_VERSION_1, DOT_OFFSET, TYPE_DIRENTRY, EMPTY_DIR_SIZE, 2);
+	
+	make_empty_dir_item (body, ih->ih_key.k_dir_id, ih->ih_key.k_objectid,
+			     le32_to_cpu (INODE_PKEY (dir)->k_dir_id), 
+			     le32_to_cpu (INODE_PKEY (dir)->k_objectid));
+    }
+    
+    /* look for place in the tree for new item */
+    retval = search_item (sb, &key, path);
+    if (retval == IO_ERROR) {
+	reiserfs_warning ("vs-13080: reiserfs_new_directory: "
+			  "i/o failure occured creating new directory\n");
+	return -EIO;
+    }
+    if (retval == ITEM_FOUND) {
+	pathrelse (path);
+	reiserfs_warning ("vs-13070: reiserfs_new_directory: "
+			  "object with this key exists (%k)", &(ih->ih_key));
+	return -EEXIST;
+    }
+
+    /* insert item, that is empty directory item */
+    return reiserfs_insert_item (th, path, &key, ih, body);
+}
+
+
+/* stat data of object has been inserted, this inserts the item
+   containing the body of symlink */
+static int reiserfs_new_symlink (struct reiserfs_transaction_handle *th, 
+				 struct item_head * ih,
+				 struct path * path, const char * symname, int item_len)
+{
+    struct super_block * sb = th->t_super;
+    struct cpu_key key;
+    int retval;
+
+    _make_cpu_key (&key, ITEM_VERSION_1, 
+		   le32_to_cpu (ih->ih_key.k_dir_id), 
+		   le32_to_cpu (ih->ih_key.k_objectid),
+		   1, TYPE_DIRECT, 3/*key length*/);
+
+    make_le_item_head (ih, 0, ITEM_VERSION_1, 1, TYPE_DIRECT, item_len, 0/*free_space*/);
+
+    /* look for place in the tree for new item */
+    retval = search_item (sb, &key, path);
+    if (retval == IO_ERROR) {
+	reiserfs_warning ("vs-13080: reiserfs_new_symlinik: "
+			  "i/o failure occured creating new symlink\n");
+	return -EIO;
+    }
+    if (retval == ITEM_FOUND) {
+	pathrelse (path);
+	reiserfs_warning ("vs-13080: reiserfs_new_symlink: "
+			  "object with this key exists (%k)", &(ih->ih_key));
+	return -EEXIST;
+    }
+
+    /* insert item, that is body of symlink */
+    return reiserfs_insert_item (th, path, &key, ih, symname);
+}
+
+
+/* inserts the stat data into the tree, and then calls
+   reiserfs_new_directory (to insert ".", ".." item if new object is
+   directory) or reiserfs_new_symlink (to insert symlink body if new
+   object is symlink) or nothing (if new object is regular file) */
+struct inode * reiserfs_new_inode (struct reiserfs_transaction_handle *th,
+				   const struct inode * dir, int mode, 
+				   const char * symname, 
+				   int i_size, /* 0 for regular, EMTRY_DIR_SIZE for dirs,
+						  strlen (symname) for symlinks)*/
+				   struct dentry *dentry, struct inode *inode, int * err)
+{
+    struct super_block * sb;
+    INITIALIZE_PATH (path_to_key);
+    struct cpu_key key;
+    struct item_head ih;
+    struct stat_data sd;
+    int retval;
+  
+    if (!dir || !dir->i_nlink) {
+	*err = -EPERM;
+	iput(inode) ;
+	return NULL;
+    }
+
+    sb = dir->i_sb;
+    inode->i_sb = sb;
+    inode->i_flags = 0;//inode->i_sb->s_flags;
+
+    /* item head of new item */
+    ih.ih_key.k_dir_id = INODE_PKEY (dir)->k_objectid;
+    ih.ih_key.k_objectid = cpu_to_le32 (reiserfs_get_unused_objectid (th));
+    if (!ih.ih_key.k_objectid) {
+	iput(inode) ;
+	*err = -ENOMEM;
+	return NULL;
+    }
+    if (old_format_only (sb))
+	make_le_item_head (&ih, 0, ITEM_VERSION_1, SD_OFFSET, TYPE_STAT_DATA, SD_V1_SIZE, MAX_US_INT);
+    else
+	make_le_item_head (&ih, 0, ITEM_VERSION_2, SD_OFFSET, TYPE_STAT_DATA, SD_SIZE, MAX_US_INT);
+
+
+    /* key to search for correct place for new stat data */
+    _make_cpu_key (&key, ITEM_VERSION_2, le32_to_cpu (ih.ih_key.k_dir_id),
+		   le32_to_cpu (ih.ih_key.k_objectid), SD_OFFSET, TYPE_STAT_DATA, 3/*key length*/);
+
+    /* find proper place for inserting of stat data */
+    retval = search_item (sb, &key, &path_to_key);
+    if (retval == IO_ERROR) {
+	iput (inode);
+	*err = -EIO;
+	return NULL;
+    }
+    if (retval == ITEM_FOUND) {
+	pathrelse (&path_to_key);
+	iput (inode);
+	*err = -EEXIST;
+	return NULL;
+    }
+
+    /* fill stat data */
+    inode->i_mode = mode;
+    inode->i_nlink = (S_ISDIR (mode) ? 2 : 1);
+    inode->i_uid = current->fsuid;
+    if (dir->i_mode & S_ISGID) {
+	inode->i_gid = dir->i_gid;
+	if (S_ISDIR(mode))
+	    inode->i_mode |= S_ISGID;
+    } else
+	inode->i_gid = current->fsgid;
+
+    inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+    inode->i_size = i_size;
+    inode->i_blocks = (inode->i_size + 511) >> 9;
+    inode->u.reiserfs_i.i_first_direct_byte = S_ISLNK(mode) ? 1 : 
+      U32_MAX/*NO_BYTES_IN_DIRECT_ITEM*/;
+
+    if (old_format_only (sb))
+	inode2sd_v1 (&sd, inode);
+    else
+	inode2sd (&sd, inode);
+
+    // these do not go to on-disk stat data
+    inode->i_ino = le32_to_cpu (ih.ih_key.k_objectid);
+    inode->i_blksize = PAGE_SIZE;
+    inode->i_dev = sb->s_dev;
+  
+    // store in in-core inode the key of stat data and version all
+    // object items will have (directory items will have old offset
+    // format, other new objects will consist of new items)
+    memcpy (INODE_PKEY (inode), &(ih.ih_key), KEY_SIZE);
+    if (old_format_only (sb) || S_ISDIR(mode) || S_ISLNK(mode))
+	inode_items_version (inode) = ITEM_VERSION_1;
+    else
+	inode_items_version (inode) = ITEM_VERSION_2;
+
+    /* insert the stat data into the tree */
+    retval = reiserfs_insert_item (th, &path_to_key, &key, &ih, (char *)(&sd));
+    if (retval) {
+	iput (inode);
+	*err = retval;
+	reiserfs_check_path(&path_to_key) ;
+	return NULL;
+    }
+
+    if (S_ISDIR(mode)) {
+	/* insert item with "." and ".." */
+	retval = reiserfs_new_directory (th, &ih, &path_to_key, dir);
+    }
+
+    if (S_ISLNK(mode)) {
+	/* insert body of symlink */
+	if (!old_format_only (sb))
+	    i_size = ROUND_UP(i_size);
+	retval = reiserfs_new_symlink (th, &ih, &path_to_key, symname, i_size);
+    }
+    if (retval) {
+      inode->i_nlink = 0;
+	iput (inode);
+	*err = retval;
+	reiserfs_check_path(&path_to_key) ;
+	return NULL;
+    }
+
+    /* not a perfect generation count, as object ids can be reused, but this
+    ** is as good as reiserfs can do right now
+    */
+    inode->i_generation = INODE_PKEY (inode)->k_dir_id;
+    insert_inode_hash (inode);
+    // we do not mark inode dirty: on disk content matches to the
+    // in-core one
+    reiserfs_check_path(&path_to_key) ;
+
+    return inode;
+}
+
+/*
+** finds the tail page in the page cache,
+** reads the last block in.
+**
+** On success, page_result is set to a locked, pinned page, and bh_result
+** is set to an up to date buffer for the last block in the file.  returns 0.
+**
+** tail conversion is not done, so bh_result might not be valid for writing
+** check buffer_mapped(bh_result) and bh_result->b_blocknr != 0 before
+** trying to write the block.
+**
+** on failure, nonzero is returned, page_result and bh_result are untouched.
+*/
+static int grab_tail_page(struct inode *p_s_inode, 
+			  struct page **page_result, 
+			  struct buffer_head **bh_result) {
+
+    /* we want the page with the last byte in the file,
+    ** not the page that will hold the next byte for appending
+    */
+    unsigned long index = (p_s_inode->i_size-1) >> PAGE_CACHE_SHIFT ;
+    unsigned long pos = 0 ;
+    unsigned long start = 0 ;
+    unsigned long blocksize = p_s_inode->i_sb->s_blocksize ;
+    unsigned long offset = (p_s_inode->i_size) & (PAGE_CACHE_SIZE - 1) ;
+    struct buffer_head *bh ;
+    struct buffer_head *head ;
+    struct page * page ;
+    int error ;
+    
+    /* we know that we are only called with inode->i_size > 0.
+    ** we also know that a file tail can never be as big as a block
+    ** If i_size % blocksize == 0, our file is currently block aligned
+    ** and it won't need converting or zeroing after a truncate.
+    */
+    if ((offset & (blocksize - 1)) == 0) {
+        return -ENOENT ;
+    }
+    page = grab_cache_page(p_s_inode->i_mapping, index) ;
+    error = PTR_ERR(page) ;
+    if (IS_ERR(page)) {
+        goto out ;
+    }
+    /* start within the page of the last block in the file */
+    start = (offset / blocksize) * blocksize ;
+
+    error = block_prepare_write(page, start, offset, 
+				reiserfs_get_block_create_0) ;
+    if (error)
+	goto unlock ;
+
+    kunmap(page) ; /* mapped by block_prepare_write */
+
+    head = page->buffers ;      
+    bh = head;
+    do {
+	if (pos >= start) {
+	    break ;
+	}
+	bh = bh->b_this_page ;
+	pos += blocksize ;
+    } while(bh != head) ;
+
+    if (!buffer_uptodate(bh)) {
+	/* note, this should never happen, prepare_write should
+	** be taking care of this for us.  If the buffer isn't up to date,
+	** I've screwed up the code to find the buffer, or the code to
+	** call prepare_write
+	*/
+	reiserfs_warning("clm-6000: error reading block %lu on dev %s\n",
+	                  bh->b_blocknr, kdevname(bh->b_dev)) ;
+	error = -EIO ;
+	goto unlock ;
+    }
+    *bh_result = bh ;
+    *page_result = page ;
+
+out:
+    return error ;
+
+unlock:
+    UnlockPage(page) ;
+    page_cache_release(page) ;
+    return error ;
+}
+
+/*
+** vfs version of truncate file.  Must NOT be called with
+** a transaction already started.
+**
+** some code taken from block_truncate_page
+*/
+void reiserfs_truncate_file(struct inode *p_s_inode, int update_timestamps) {
+    struct reiserfs_transaction_handle th ;
+    int windex ;
+
+    /* we want the offset for the first byte after the end of the file */
+    unsigned long offset = p_s_inode->i_size & (PAGE_CACHE_SIZE - 1) ;
+    unsigned blocksize = p_s_inode->i_sb->s_blocksize ;
+    unsigned length ;
+    struct page *page = NULL ;
+    int error ;
+    struct buffer_head *bh = NULL ;
+
+    if (p_s_inode->i_size > 0) {
+        if ((error = grab_tail_page(p_s_inode, &page, &bh))) {
+	    // -ENOENT means we truncated past the end of the file, 
+	    // and get_block_create_0 could not find a block to read in,
+	    // which is ok.
+	    if (error != -ENOENT)
+	        reiserfs_warning("clm-6001: grab_tail_page failed %d\n", error);
+	    page = NULL ;
+	    bh = NULL ;
+	}
+    }
+
+    /* so, if page != NULL, we have a buffer head for the offset at 
+    ** the end of the file. if the bh is mapped, and bh->b_blocknr != 0, 
+    ** then we have an unformatted node.  Otherwise, we have a direct item, 
+    ** and no zeroing is required.  We zero after the truncate, because the 
+    ** truncate might pack the item anyway (it will unmap bh if it packs).
+    */
+    prevent_flush_page_lock(page, p_s_inode) ;
+    journal_begin(&th, p_s_inode->i_sb,  JOURNAL_PER_BALANCE_CNT * 2 ) ;
+    windex = push_journal_writer("reiserfs_vfs_truncate_file") ;
+    reiserfs_do_truncate (&th, p_s_inode, page, update_timestamps) ;
+    pop_journal_writer(windex) ;
+    journal_end(&th, p_s_inode->i_sb,  JOURNAL_PER_BALANCE_CNT * 2 ) ;
+    allow_flush_page_lock(page, p_s_inode) ;
+
+    if (page && buffer_mapped(bh) && bh->b_blocknr != 0) {
+        length = offset & (blocksize - 1) ;
+	/* if we are not on a block boundary */
+	if (length) {
+	    length = blocksize - length ;
+	    memset((char *)kmap(page) + offset, 0, length) ;   
+	    flush_dcache_page(page) ;
+	    kunmap(page) ;
+	    mark_buffer_dirty(bh) ;
+	}
+    } 
+
+    if (page) {
+	UnlockPage(page) ;
+	page_cache_release(page) ;
+    }
+    return ;
+}
+
+static int map_block_for_writepage(struct inode *inode, 
+			       struct buffer_head *bh_result, 
+                               unsigned long block) {
+    struct reiserfs_transaction_handle th ;
+    int fs_gen ;
+    struct item_head tmp_ih ;
+    struct item_head *ih ;
+    struct buffer_head *bh ;
+    __u32 *item ;
+    struct cpu_key key ;
+    INITIALIZE_PATH(path) ;
+    int pos_in_item ;
+    int jbegin_count = JOURNAL_PER_BALANCE_CNT ;
+    loff_t byte_offset = (block << inode->i_sb->s_blocksize_bits) + 1 ;
+    int retval ;
+    int use_get_block = 0 ;
+    int bytes_copied = 0 ;
+    int copy_size ;
+
+start_over:
+    lock_kernel() ;
+    prevent_flush_page_lock(bh_result->b_page, inode) ;
+    journal_begin(&th, inode->i_sb, jbegin_count) ;
+
+    make_cpu_key(&key, inode, byte_offset, TYPE_ANY, 3) ;
+
+research:
+    retval = search_for_position_by_key(inode->i_sb, &key, &path) ;
+    if (retval != POSITION_FOUND) {
+        use_get_block = 1;
+	goto out ;
+    } 
+
+    bh = get_bh(&path) ;
+    ih = get_ih(&path) ;
+    item = get_item(&path) ;
+    pos_in_item = path.pos_in_item ;
+
+    /* we've found an unformatted node */
+    if (indirect_item_found(retval, ih)) {
+	if (bytes_copied > 0) {
+	    reiserfs_warning("clm-6002: bytes_copied %d\n", bytes_copied) ;
+	}
+        if (!item[pos_in_item]) {
+	    /* crap, we are writing to a hole */
+	    use_get_block = 1;
+	    goto out ;
+	}
+	set_block_dev_mapped(bh_result, le32_to_cpu(item[pos_in_item]), inode);
+    } else if (is_direct_le_ih(ih)) {
+        char *p ; 
+        p = page_address(bh_result->b_page) ;
+        p += (byte_offset -1) & (PAGE_CACHE_SIZE - 1) ;
+        copy_size = le16_to_cpu(ih->ih_item_len) - pos_in_item ;
+
+	fs_gen = get_generation(inode->i_sb) ;
+	copy_item_head(&tmp_ih, ih) ;
+	reiserfs_prepare_for_journal(inode->i_sb, bh, 1) ;
+	if (fs_changed (fs_gen, inode->i_sb) && item_moved (&tmp_ih, &path)) {
+	    reiserfs_restore_prepared_buffer(inode->i_sb, bh) ;
+	    goto research;
+	}
+
+	memcpy( B_I_PITEM(bh, ih) + pos_in_item, p + bytes_copied, copy_size) ;
+
+	journal_mark_dirty(&th, inode->i_sb, bh) ;
+	bytes_copied += copy_size ;
+	set_block_dev_mapped(bh_result, 0, inode);
+
+	/* are there still bytes left? */
+        if (bytes_copied < bh_result->b_size && 
+	    (byte_offset + bytes_copied) < inode->i_size) {
+	    set_cpu_key_k_offset(&key, cpu_key_k_offset(&key) + copy_size) ;
+	    goto research ;
+	}
+    } else {
+        reiserfs_warning("clm-6003: bad item inode %lu, device %s\n", inode->i_ino, kdevname(inode->i_sb->s_dev)) ;
+        retval = -EIO ;
+	goto out ;
+    }
+    retval = 0 ;
+    
+out:
+    pathrelse(&path) ;
+    journal_end(&th, inode->i_sb, jbegin_count) ;
+    allow_flush_page_lock(bh_result->b_page, inode) ;
+    unlock_kernel() ;
+
+    /* this is where we fill in holes in the file. */
+    if (use_get_block) {
+        kmap(bh_result->b_page) ;
+	retval = reiserfs_get_block(inode, block, bh_result, 1) ;
+        kunmap(bh_result->b_page) ;
+	if (!retval) {
+	    if (!buffer_mapped(bh_result) || bh_result->b_blocknr == 0) {
+	        /* get_block failed to find a mapped unformatted node. */
+		use_get_block = 0 ;
+		goto start_over ;
+	    }
+	}
+    }
+    return retval ;
+}
+
+/* helper func to get a buffer head ready for writepage to send to
+** ll_rw_block
+*/
+static inline void submit_bh_for_writepage(struct buffer_head **bhp, int nr) {
+    struct buffer_head *bh ;
+    int i;
+    for(i = 0 ; i < nr ; i++) {
+        bh = bhp[i] ;
+	lock_buffer(bh) ;
+	atomic_inc(&bh->b_count) ; /* async end_io handler decs this */
+	set_buffer_async_io(bh) ;
+	/* submit_bh doesn't care if the buffer is dirty, but nobody
+	** later on in the call chain will be cleaning it.  So, we
+	** clean the buffer here, it still gets written either way.
+	*/
+	clear_bit(BH_Dirty, &bh->b_state) ;
+	set_bit(BH_Uptodate, &bh->b_state) ;
+	submit_bh(WRITE, bh) ;
+    }
+}
+
+static int reiserfs_write_full_page(struct page *page) {
+    struct inode *inode = page->mapping->host ;
+    unsigned long end_index = inode->i_size >> PAGE_CACHE_SHIFT ;
+    unsigned last_offset = PAGE_CACHE_SIZE;
+    int error = 0;
+    unsigned long block ;
+    unsigned cur_offset = 0 ;
+    struct buffer_head *head, *bh ;
+    int partial = 0 ;
+    struct buffer_head *arr[PAGE_CACHE_SIZE/512] ;
+    int nr = 0 ;
+
+    if (!page->buffers) {
+        block_prepare_write(page, 0, 0, NULL) ;
+	kunmap(page) ;
+    }
+    /* last page in the file, zero out any contents past the
+    ** last byte in the file
+    */
+    if (page->index >= end_index) {
+        last_offset = inode->i_size & (PAGE_CACHE_SIZE - 1) ;
+	/* no file contents in this page */
+	if (page->index >= end_index + 1 || !last_offset) {
+	    error =  -EIO ;
+	    goto fail ;
+	}
+	memset((char *)kmap(page)+last_offset, 0, PAGE_CACHE_SIZE-last_offset) ;
+	flush_dcache_page(page) ;
+	kunmap(page) ;
+    }
+    head = page->buffers ;
+    bh = head ;
+    block = page->index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits) ;
+    do {
+	/* if this offset in the page is outside the file */
+	if (cur_offset >= last_offset) {
+	    if (!buffer_uptodate(bh))
+	        partial = 1 ;
+	} else {
+	    /* fast path, buffer mapped to an unformatted node */
+	    if (buffer_mapped(bh) && bh->b_blocknr != 0) {
+		arr[nr++] = bh ;
+	    } else {
+		/* buffer not mapped yet, or points to a direct item.
+		** search and dirty or log
+		*/
+		if ((error = map_block_for_writepage(inode, bh, block))) {
+		    goto fail ;
+		}
+		/* map_block_for_writepage either found an unformatted node
+		** and mapped it for us, or it found a direct item
+		** and logged the changes.  
+		*/
+		if (buffer_mapped(bh) && bh->b_blocknr != 0) {
+		    arr[nr++] = bh ;
+		}
+	    }
+	}
+        bh = bh->b_this_page ;
+	cur_offset += bh->b_size ;
+	block++ ;
+    } while(bh != head) ;
+
+    /* if this page only had a direct item, it is very possible for
+    ** nr == 0 without there being any kind of error.
+    */
+    if (nr) {
+        submit_bh_for_writepage(arr, nr) ;
+    } else {
+        UnlockPage(page) ;
+    }
+    if (!partial)
+        SetPageUptodate(page) ;
+
+    return 0 ;
+
+fail:
+    if (nr) {
+        submit_bh_for_writepage(arr, nr) ;
+    } else {
+        UnlockPage(page) ;
+    }
+    ClearPageUptodate(page) ;
+    return error ;
+}
+
+//
+// this is exactly what 2.3.99-pre9's ext2_readpage is
+//
+static int reiserfs_readpage (struct file *f, struct page * page)
+{
+    return block_read_full_page (page, reiserfs_get_block);
+}
+
+
+//
+// modified from ext2_writepage is
+//
+static int reiserfs_writepage (struct page * page)
+{
+    struct inode *inode = page->mapping->host ;
+    reiserfs_wait_on_write_block(inode->i_sb) ;
+    return reiserfs_write_full_page(page) ;
+}
+
+
+//
+// from ext2_prepare_write, but modified
+//
+int reiserfs_prepare_write(struct file *f, struct page *page, unsigned from, unsigned to) {
+    struct inode *inode = page->mapping->host ;
+    reiserfs_wait_on_write_block(inode->i_sb) ;
+    fix_tail_page_for_writing(page) ;
+    return block_prepare_write(page, from, to, reiserfs_get_block) ;
+}
+
+
+//
+// this is exactly what 2.3.99-pre9's ext2_bmap is
+//
+static int reiserfs_aop_bmap(struct address_space *as, long block) {
+  return generic_block_bmap(as, block, reiserfs_bmap) ;
+}
+
+
+static int reiserfs_commit_write(struct file *f, struct page *page, 
+                                 unsigned from, unsigned to) {
+    struct inode *inode = page->mapping->host ;
+    int ret ; 
+    struct reiserfs_transaction_handle th ;
+    
+    reiserfs_wait_on_write_block(inode->i_sb) ;
+    lock_kernel();
+    prevent_flush_page_lock(page, inode) ;
+    ret = generic_commit_write(f, page, from, to) ;
+    /* we test for O_SYNC here so we can commit the transaction
+    ** for any packed tails the file might have had
+    */
+    if (f->f_flags & O_SYNC) {
+	journal_begin(&th, inode->i_sb, 1) ;
+	reiserfs_prepare_for_journal(inode->i_sb, 
+	                             SB_BUFFER_WITH_SB(inode->i_sb), 1) ;
+	journal_mark_dirty(&th, inode->i_sb, SB_BUFFER_WITH_SB(inode->i_sb)) ;
+	journal_end_sync(&th, inode->i_sb, 1) ;
+    }
+    allow_flush_page_lock(page, inode) ;
+    unlock_kernel();
+    return ret ;
+}
+
+struct address_space_operations reiserfs_address_space_operations = {
+    writepage: reiserfs_writepage,
+    readpage: reiserfs_readpage, 
+    sync_page: block_sync_page,
+    prepare_write: reiserfs_prepare_write,
+    commit_write: reiserfs_commit_write,
+    bmap: reiserfs_aop_bmap
+} ;

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)