linux-toradex.git/fs/nilfs2/btree.c, branch v2.6.32.45

nilfs2: allow btree code to directly call dat operations

2009-09-14T09:27:16+00:00

The current btree code is written so that btree functions call dat
operations via wrapper functions in bmap.c when they allocate, free,
or modify virtual block addresses.

This abstraction requires additional function calls and causes
frequent call of nilfs_bmap_get_dat() function since it is used in the
every wrapper function.

This removes the wrapper functions and makes them available from
btree.c and direct.c, which will increase the opportunity of
compiler optimization.

Signed-off-by: Ryusuke Konishi

nilfs2: stop zero-fill of btree path just before free it

2009-09-14T09:27:15+00:00

The btree path object is cleared just before it is freed.

This will remove the code doing the unnecessary clear operation.

Signed-off-by: Ryusuke Konishi

nilfs2: remove unused btree argument from btree functions

2009-09-14T09:27:15+00:00

Even though many btree functions take a btree object as their first
argument, most of them are not used in their functions.

This sticky use of the btree argument is hurting code readability and
giving the possibility of inefficient code generation.

So, this removes the unnecessary btree arguments.

Signed-off-by: Ryusuke Konishi

nilfs2: support contiguous lookup of blocks

2009-06-10T14:41:12+00:00

Although get_block() callback function can return extent of contiguous
blocks with bh->b_size, nilfs_get_block() function did not support
this feature.

This adds contiguous lookup feature to the block mapping codes of
nilfs, and allows the nilfs_get_blocks() function to return the extent
information by applying the feature.

Signed-off-by: Ryusuke Konishi

nilfs2: remove nilfs_btree_operations from btree mapping

2009-06-10T14:41:11+00:00

will remove indirect function calls using nilfs_btree_operations
table.

Signed-off-by: Ryusuke Konishi

nilfs2: remove bmap pointer operations

2009-06-10T14:41:10+00:00

Previously, the bmap codes of nilfs used three types of function
tables.  The abuse of indirect function calls decreased source
readability and suffered many indirect jumps which would confuse
branch prediction of processors.

This eliminates one type of the function tables,
nilfs_bmap_ptr_operations, which was used to dispatch low level
pointer operations of the nilfs bmap.

This adds a new integer variable "b_ptr_type" to nilfs_bmap struct,
and uses the value to select the pointer operations.

Signed-off-by: Ryusuke Konishi

nilfs2: remove useless b_low and b_high fields from nilfs_bmap struct

2009-06-10T14:41:10+00:00

This will cut off 16 bytes from the nilfs_bmap struct which is
embedded in the on-memory inode of nilfs.

The b_high field was never used, and the b_low field stores a constant
value which can be determined by whether the inode uses btree for
block mapping or not.

Signed-off-by: Ryusuke Konishi

nilfs2: remove pointless NULL check of bpop_commit_alloc_ptr function

2009-06-10T14:41:10+00:00

This indirect function is set to NULL only for gc cache inodes, but
the gc cache inodes never call this function.

Signed-off-by: Ryusuke Konishi

nilfs2: move get block functions in bmap.c into btree codes

2009-06-10T14:41:10+00:00

Two get block function for btree nodes, nilfs_bmap_get_block() and
nilfs_bmap_get_new_block(), are called only from the btree codes.
This relocation will increase opportunities of compiler optimization.

Signed-off-by: Ryusuke Konishi

nilfs2: remove nilfs_bmap_delete_block

2009-06-10T14:41:10+00:00

nilfs_bmap_delete_block() is a wrapper function calling
nilfs_btnode_delete().  This removes it for simplicity.

Signed-off-by: Ryusuke Konishi