linux-toradex.git/fs/nilfs2/btree.c, branch tegra-11.2.2

nilfs2: apply read-ahead for nilfs_btree_lookup_contig

2010-07-23T01:02:16+00:00

This applies read-ahead to nilfs_btree_do_lookup and
nilfs_btree_lookup_contig functions and extends them to read ahead
siblings of level 1 btree nodes that hold data blocks.

At present, the read-ahead is not applied to most btree operations;
only get_block() callback function, which is used during read of
regular files or directories, receives the benefit.

Signed-off-by: Ryusuke Konishi

nilfs2: introduce check flag to btree node buffer

2010-07-23T01:02:15+00:00

nilfs_btree_get_block() now may return untested buffer due to
read-ahead.  This adds a new flag for buffer heads so that the btree
code can check whether the buffer is already verified or not.

Signed-off-by: Ryusuke Konishi

nilfs2: add btree get block function with readahead option

2010-07-23T01:02:15+00:00

This adds __nilfs_btree_get_block() function that can issue a series
of read-ahead requests for sibling btree nodes.

This read-ahead needs parent node block, so nilfs_btree_readahead_info
structure is added to pass the information that
__nilfs_btree_get_block() needs.

This also replaces the previous nilfs_btree_get_block() implementation
with a wrapper function of __nilfs_btree_get_block().

Signed-off-by: Ryusuke Konishi

nilfs2: add read ahead mode to nilfs_btnode_submit_block

2010-07-23T01:02:15+00:00

This adds mode argument to nilfs_btnode_submit_block() function and
allows it to issue a read-ahead request.

An optional submit_ptr argument is also added to store the actual
block address for which bio is sent.  submit_ptr is used for a series
of read-ahead requests, and helps to decide if each requested block is
continous to the previous one on disk.

Signed-off-by: Ryusuke Konishi

nilfs2: eliminate inline keywords in btree implementation

2010-07-23T01:02:15+00:00

This removes all inline uses from btree.c.  Gcc now agressively apply
inline expansion even for the functions declared without the keyword;
the inline use in btree.c looks excessive.

Signed-off-by: Ryusuke Konishi

nilfs2: get maximum number of child nodes from bmap object

2010-07-23T01:02:14+00:00

The patch "reduce repetitive calculation of max number of child nodes"
gathered up the calculation of maximum number of child nodes into
nilfs_btree_nchildren_per_block() function.  This makes the function
get resultant value from a private variable in bmap object instead of
calculating it for each call.

Signed-off-by: Ryusuke Konishi

nilfs2: reduce repetitive calculation of max number of child nodes

2010-07-23T01:02:14+00:00

The current btree implementation repeats the same calculation on the
maximum number of child nodes.  This is because a few low level
routines use the calculation for index addressing in a btree node
block.

This reduces the calculation by explicitly passing the maximum number
of child nodes (ncmax) through their argument.

This changes parameter passing of the following functions:

 - nilfs_btree_node_dptrs
 - nilfs_btree_node_get_ptr
 - nilfs_btree_node_set_ptr
 - nilfs_btree_node_init
 - nilfs_btree_node_move_left
 - nilfs_btree_node_move_right
 - nilfs_btree_node_insert
 - nilfs_btree_node_delete, and
 - nilfs_btree_get_node

The following functions are removed:

 - nilfs_btree_node_nchildren_min
 - nilfs_btree_node_nchildren_max

Most middle level btree operations are rewritten to pass a proper
ncmax value depending on whether each occurrence of node is "root" or
not.

A constant NILFS_BTREE_ROOT_NCHILDREN_MAX is used for the root node,
whereas nilfs_btree_nchildren_per_block() function is used for
non-root nodes.  If a node could be either root or a non-root node, an
output argument of nilfs_btree_get_node() is used to set up ncmax.

Signed-off-by: Ryusuke Konishi

nilfs2: optimize calculation of min/max number of btree node children

2010-07-23T01:02:14+00:00

nilfs_btree_node_nchildren_max() and nilfs_btree_node_nchildren_min()
functions switch return value depending on whether target node is the
root or a node block.  In most uses of these functions, however, the
node type is fixed, and moreover the same calculation is repeatedly
performed in loop.

This unfold these functions depending on context and move them outside
loops wherever possible.

Signed-off-by: Ryusuke Konishi

nilfs2: remove redundant pointer checks in bmap lookup functions

2010-07-23T01:02:14+00:00

nilfs_bmap_lookup and its variants are supposed to take a valid
pointer argument to return a block address, thus pointer checks in
nilfs_btree_lookup and nilfs_direct_lookup are needless.

Signed-off-by: Ryusuke Konishi

nilfs2: unify bmap set_target_v operations

2010-07-23T01:02:14+00:00

This unifies two similar functions nilfs_btree_set_target_v and
nilfs_direct_set_target_v into one, nilfs_bmap_set_target_v.

Signed-off-by: Ryusuke Konishi