/*
* Get delimiting key of the buffer by looking for it in the buffers in
* the path, starting from the bottom of the path, and going upwards. We
* must check the path's validity at each step. If the key is not in the
* path, there is no delimiting key in the tree (buffer is first or last
* buffer in tree), and in this case we return a special key, either
* MIN_KEY or MAX_KEY.
*/
const struct key *
get_lkey(const struct path *p_s_chk_path,
const struct reiserfs_sb_info *p_s_sbi)
{
struct buf *p_s_parent;
int n_position, n_path_offset = p_s_chk_path->path_length;
/* While not higher in path than first element. */
while (n_path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
/* Parent at the path is not in the tree now. */
if (!B_IS_IN_TREE(p_s_parent =
PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)))
return (&MAX_KEY);
/* Check whether position in the parent is correct. */
if ((n_position = PATH_OFFSET_POSITION(p_s_chk_path,
n_path_offset)) > B_NR_ITEMS(p_s_parent))
return (&MAX_KEY);
/*
* Check whether parent at the path really points to
* the child.
*/
if (B_N_CHILD_NUM(p_s_parent, n_position) !=
(PATH_OFFSET_PBUFFER(p_s_chk_path,
n_path_offset + 1)->b_blkno
/ btodb(p_s_sbi->s_blocksize)))
return (&MAX_KEY);
/*
* Return delimiting key if position in the parent is not
* equal to zero.
*/
if (n_position)
return (B_N_PDELIM_KEY(p_s_parent, n_position - 1));
}
/* Return MIN_KEY if we are in the root of the buffer tree. */
if ((PATH_OFFSET_PBUFFER(p_s_chk_path,
FIRST_PATH_ELEMENT_OFFSET)->b_blkno
/ btodb(p_s_sbi->s_blocksize)) == SB_ROOT_BLOCK(p_s_sbi))
return (&MIN_KEY);
return (&MAX_KEY);
}
/* Get delimiting key of the buffer by looking for it in the buffers in the path, starting from the bottom
of the path, and going upwards. We must check the path's validity at each step. If the key is not in
the path, there is no delimiting key in the tree (buffer is first or last buffer in tree), and in this
case we return a special key, either MIN_KEY or MAX_KEY. */
static inline const struct reiserfs_key *get_lkey(const struct treepath *chk_path,
const struct super_block *sb)
{
int position, path_offset = chk_path->path_length;
struct buffer_head *parent;
RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
"PAP-5010: invalid offset in the path");
/* While not higher in path than first element. */
while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
RFALSE(!buffer_uptodate
(PATH_OFFSET_PBUFFER(chk_path, path_offset)),
"PAP-5020: parent is not uptodate");
/* Parent at the path is not in the tree now. */
if (!B_IS_IN_TREE
(parent =
PATH_OFFSET_PBUFFER(chk_path, path_offset)))
return &MAX_KEY;
/* Check whether position in the parent is correct. */
if ((position =
PATH_OFFSET_POSITION(chk_path,
path_offset)) >
B_NR_ITEMS(parent))
return &MAX_KEY;
/* Check whether parent at the path really points to the child. */
if (B_N_CHILD_NUM(parent, position) !=
PATH_OFFSET_PBUFFER(chk_path,
path_offset + 1)->b_blocknr)
return &MAX_KEY;
/* Return delimiting key if position in the parent is not equal to zero. */
if (position)
return B_N_PDELIM_KEY(parent, position - 1);
}
/* Return MIN_KEY if we are in the root of the buffer tree. */
if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
b_blocknr == SB_ROOT_BLOCK(sb))
return &MIN_KEY;
return &MAX_KEY;
}
/* Get delimiting key of the buffer at the path and its right neighbor. */
inline struct key * get_rkey (
struct path * p_s_chk_path,
struct super_block * p_s_sb
) {
int n_position,
n_path_offset = p_s_chk_path->path_length;
struct buffer_head * p_s_parent;
#ifdef CONFIG_REISERFS_CHECK
if ( n_path_offset < FIRST_PATH_ELEMENT_OFFSET )
reiserfs_panic(p_s_sb,"PAP-5030: get_rkey: illegal offset in the path");
#endif
while ( n_path_offset-- > FIRST_PATH_ELEMENT_OFFSET ) {
#ifdef CONFIG_REISERFS_CHECK
if ( ! buffer_uptodate(PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)) )
reiserfs_panic(p_s_sb, "PAP-5040: get_rkey: parent is not uptodate");
#endif
/* Parent at the path is not in the tree now. */
if ( ! B_IS_IN_TREE(p_s_parent = PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)) )
return &MIN_KEY;
/* Check whether position in the parrent is correct. */
if ( (n_position = PATH_OFFSET_POSITION(p_s_chk_path, n_path_offset)) > B_NR_ITEMS(p_s_parent) )
return &MIN_KEY;
/* Check whether parent at the path really points to the child. */
if ( B_N_CHILD_NUM(p_s_parent, n_position) !=
PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset + 1)->b_blocknr )
return &MIN_KEY;
/* Return delimiting key if position in the parent is not the last one. */
if ( n_position != B_NR_ITEMS(p_s_parent) )
return B_N_PDELIM_KEY(p_s_parent, n_position);
}
/* Return MAX_KEY if we are in the root of the buffer tree. */
if ( PATH_OFFSET_PBUFFER(p_s_chk_path, FIRST_PATH_ELEMENT_OFFSET)->b_blocknr ==
SB_ROOT_BLOCK (p_s_sb) )
return &MAX_KEY;
return &MIN_KEY;
}