linux-stable.git/fs/gfs2/bmap.c, branch linux-3.3.y

GFS2: decouple quota allocations from block allocations

2011-11-22T10:25:21+00:00

This patch separates the code pertaining to allocations into two
parts: quota-related information and block reservations.
This patch also moves all the block reservation structure allocations to
function gfs2_inplace_reserve to simplify the code, and moves
the frees to function gfs2_inplace_release.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: move toward a generic multi-block allocator

2011-11-21T10:04:09+00:00

This patch is a revision of the one I previously posted.
I tried to integrate all the suggestions Steve gave.
The purpose of the patch is to change function gfs2_alloc_block
(allocate either a dinode block or an extent of data blocks)
to a more generic gfs2_alloc_blocks function that can
allocate both a dinode _and_ an extent of data blocks in the
same call. This will ultimately help us create a multi-block
reservation scheme to reduce file fragmentation.

This patch moves more toward a generic multi-block allocator that
takes a pointer to the number of data blocks to allocate, plus whether
or not to allocate a dinode. In theory, it could be called to allocate
(1) a single dinode block, (2) a group of one or more data blocks, or
(3) a dinode plus several data blocks.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: combine gfs2_alloc_block and gfs2_alloc_di

2011-11-15T15:25:03+00:00

GFS2 functions gfs2_alloc_block and gfs2_alloc_di do basically
the same things, with a few exceptions. This patch combines
the two functions into a slightly more generic gfs2_alloc_block.
Having one centralized block allocation function will reduce
code redundancy and make it easier to implement multi-block
reservations to reduce file fragmentation in the future.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: More automated code analysis fixes

2011-11-08T14:04:20+00:00

A potentially uninitialised variable, some unreachable code,
and the main part of this, fixing the error path in the
unlink function.

Signed-off-by: Steven Whitehouse

GFS2: Move readahead of metadata during deallocation into its own function

2011-10-21T11:39:54+00:00

Move the recently added readahead of the indirect pointer
tree during deallocation into its own function in order
that we can use it elsewhere in the future. Also this
fixes the resetting of the "first" variable in the
original patch.

Signed-off-by: Steven Whitehouse

GFS2: rewrite fallocate code to write blocks directly

2011-10-21T11:39:49+00:00

GFS2's fallocate code currently goes through the page cache. Since it's only
writing to the end of the file or to holes in it, it doesn't need to, and it
was causing issues on low memory environments. This patch pulls in some of
Steve's block allocation work, and uses it to simply allocate the blocks for
the file, and zero them out at allocation time.  It provides a slight
performance increase, and it dramatically simplifies the code.

Signed-off-by: Benjamin Marzinski 
Signed-off-by: Steven Whitehouse

GFS2: speed up delete/unlink performance for large files

2011-10-21T11:39:47+00:00

This patch improves the performance of delete/unlink
operations in a GFS2 file system where the files are large
by adding a layer of metadata read-ahead for indirect blocks.
Mileage will vary, but on my system, deleting an 8.6G file
dropped from 22 seconds to about 4.5 seconds.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: Use cached rgrp in gfs2_rlist_add()

2011-10-21T11:39:39+00:00

Each block which is deallocated, requires a call to gfs2_rlist_add()
and each of those calls was calling gfs2_blk2rgrpd() in order to
figure out which rgrp the block belonged in. This can be speeded up
by making use of the rgrp cached in the inode. We also reset this
cached rgrp in case the block has changed rgrp. This should provide
a big reduction in gfs2_blk2rgrpd() calls during deallocation.

Signed-off-by: Steven Whitehouse

GFS2: Call do_strip() directly from recursive_scan()

2011-10-21T11:39:38+00:00

The recursive_scan() function only ever takes a single "bc"
argument, so we might as well just call do_strip() directly
from resource_scan() rather than pass it in as an argument.

Also the "data" argument is always a struct strip_mine, so
we can pass that in, rather than using a void pointer.

This also moves do_strip() ahead of recursive_scan() so that
we don't need to add a prototype.

Signed-off-by: Steven Whitehouse

GFS2: Make resource groups "append only" during life of fs

2011-10-21T11:39:33+00:00

Since we have ruled out supporting online filesystem shrink,
it is possible to make the resource group list append only
during the life of a super block. This gives several benefits:

Firstly, we only need to read new rindex elements as they are added
rather than needing to reread the whole rindex file each time one
element is added.

Secondly, the rindex glock can be held for much shorter periods of
time, and is completely removed from the fast path for allocations.
The lock is taken in shared mode only when updating the resource
groups when the first allocation occurs, and after a grow has
taken place.

Thirdly, this results in a reduction in code size, and everything
gets a lot simpler to understand in this area.

Signed-off-by: Steven Whitehouse