Actually the whole reflink will touch refcount tree 2 times:
1. It will add the clusters in the extent record to the tree if it
isn't refcounted before.
2. It will add 1 refcount to these clusters when it add these
extent records to the tree.
So actually we shouldn't do merge in the 1st operation since the 2nd
one will soon be called and we may have to split it again. Do a merge
first and split soon is a waste of time. So we only merge in the 2nd
round. This is done by adding a new internal __ocfs2_increase_refcount
and call it with "not-merge" for 1st refcount operation in reflink.
This also has a side-effect that we don't need to worry too much about
the metadata allocation in the 2nd round since it will only merge and
no split will happen for those records.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
The old xattr value remove is quite simple, it just erase the
tree and free the clusters. But as we have added refcount support,
The process is a little complicated.
We have to lock the refcount tree at the beginning, what's more,
we may split the refcount tree in some cases, so meta/credits are
needed.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
With reflink, there is a need that we create a new xattr indexed
block from the very beginning. So add a new parameter for
ocfs2_create_xattr_block.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Now with xattr refcount support, we need to check whether
we have xattr refcounted before we remove the refcount tree.
Now the mechanism is:
1) Check whether i_clusters == 0, if no, exit.
2) check whether we have i_xattr_loc in dinode. if yes, exit.
2) Check whether we have inline xattr stored outside, if yes, exit.
4) Remove the tree.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
In ocfs2, when xattr's value is larger than OCFS2_XATTR_INLINE_SIZE,
it will be kept outside of the blocks we store xattr entry. And they
are stored in a b-tree also. So this patch try to attach all these
clusters to refcount tree also.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Currently we have ocfs2_iterate_xattr_buckets which can receive
a para and a callback to iterate a series of bucket. It is good.
But actually the 2 callers ocfs2_xattr_tree_list_index_block and
ocfs2_delete_xattr_index_block are almost the same. The only
difference is that the latter need to handle the extent record
also. So add a new function named ocfs2_iterate_xattr_index_block.
It can be given func callback which are used for exten record.
So now we only have one iteration function for the xattr index
block. Ane what's more, it is useful for our future reflink
operations.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
In order to make 2 transcation(xattr and cow) independent with each other,
we CoW the whole xattr out in case we are setting them.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
We currently use pagecache to duplicate clusters in CoW,
but it isn't suitable for xattr case. So abstract it out
so that the caller can decide which method it use.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
With the new refcount tree, xattr value can also be refcounted
among multiple files. So return the appropriate extent flags
so that CoW can used it later.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
A reflink creates a snapshot of a file, that means the attributes
must be identical except for three exceptions - nlink, ino, and ctime.
As for time changes, Here is a brief description:
1. Source file:
1) atime: Ignore. Let the lazy atime code handle that.
2) mtime: don't touch.
3) ctime: If we change the tree (adding REFCOUNTED to at least one
extent), update it.
2. Destination file:
1) atime: ignore.
2) mtime: we want it to appear identical to the source.
3) ctime: update.
The idea here is that an ls -l will show the same time for the
src and target - it shows mtime. Backup software like rsync and tar
will treat the new file correctly too.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2 major functions are added in this patch.
ocfs2_attach_refcount_tree will create a new refcount tree to the
old file if it doesn't have one and insert all the extent records
to the tree if they are not refcounted.
ocfs2_create_reflink_node will:
1. set the refcount tree to the new file.
2. call ocfs2_duplicate_extent_list which will iterate all the
extents for the old file, insert it to the new file and increase
the corresponding referennce count.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
When we truncate a file to a specific size which resides in a reflinked
cluster, we need to CoW it since ocfs2_zero_range_for_truncate will
zero the space after the size(just another type of write).
So we add a "max_cpos" in ocfs2_refcount_cow so that it will stop when
it hit the max cluster offset.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
When we use mmap, we CoW the refcountd clusters in
ocfs2_write_begin_nolock. While for normal file
io(including directio), we do CoW in
ocfs2_prepare_inode_for_write.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
During CoW, if the old extent record is refcounted, we allocate
som new clusters and do CoW. Actually we can have some improvement
here. If the old extent has refcount=1, that means now it is only
used by this file. So we don't need to allocate new clusters, just
remove the refcounted flag and it is OK. We also have to remove
it from the refcount tree while not deleting it.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
This patch try CoW support for a refcounted record.
the whole process will be:
1. Calculate how many clusters we need to CoW and where we start.
Extents that are not completely encompassed by the write will
be broken on 1MB boundaries.
2. Do CoW for the clusters with the help of page cache.
3. Change the b-tree structure with the new allocated clusters.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Add 'Decrement refcount for delete' in to the normal truncate
process. So for a refcounted extent record, call refcount rec
decrementation instead of cluster free.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Given a physical cpos and length, decrement the refcount
in the tree. If the refcount for any portion of the extent goes
to zero, that portion is queued for freeing.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Given a physical cpos and length, increment the refcount
in the tree. If the extent has not been seen before, a refcount
record is created for it. Refcount records may be merged or
split by this operation.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Now fs/ocfs2/alloc.c has more than 7000 lines. It contains our
basic b-tree operation. Although we have already make our b-tree
operation generic, the basic structrue ocfs2_path which is used
to iterate one b-tree branch is still static and limited to only
used in alloc.c. As refcount tree need them and I don't want to
add any more b-tree unrelated code to alloc.c, export them out.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Add refcount b-tree as a new extent tree so that it can
use the b-tree to store and maniuplate ocfs2_refcount_rec.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
ocfs2_mark_extent_written actually does the following things:
1. check the parameters.
2. initialize the left_path and split_rec.
3. call __ocfs2_mark_extent_written. it will do:
1) check the flags of unwritten
2) do the real split work.
The whole process is packed tightly somehow. So this patch
will abstract 2 different functions so that future b-tree
operation can work with it.
1. __ocfs2_split_extent will accept path and split_rec and do
the real split work.
2. ocfs2_change_extent_flag will accept a new flag and initialize
path and split_rec.
So now ocfs2_mark_extent_written will do:
1. check the parameters.
2. call ocfs2_change_extent_flag.
1) initalize the left_path and split_rec.
2) check whether the new flags conflict with the old one.
3) call __ocfs2_split_extent to do the split.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Add a new operation eo_ocfs2_extent_contig int the extent tree's
operations vector. So that with the new refcount tree, We want
this so that refcount trees can always return CONTIG_NONE and
prevent extent merging.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Implement locking around struct ocfs2_refcount_tree. This protects
all read/write operations on refcount trees. ocfs2_refcount_tree
has its own lock and its own caching_info, protecting buffers among
multiple nodes.
User must call ocfs2_lock_refcount_tree before his operation on
the tree and unlock it after that.
ocfs2_refcount_trees are referenced by the block number of the
refcount tree root block, So we create an rb-tree on the ocfs2_super
to look them up.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
refcount tree should use its own caching info so that when
we downconvert the refcount tree lock, we can drop all the
cached buffer head.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
In meta downconvert, we need to checkpoint the metadata in an inode.
For refcount tree, we also need it. So abstract the process out.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Only 32 bits of system call number are meaningful, so make the
specification for syscall_get_nr() be to return int, not long.
Signed-off-by: Roland McGrath <roland@redhat.com>
Provide some brief documentation of some of the design decisions that
are made by the regulator API.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Currently, when the physical resume CPU is not equal to the physical suspend
CPU, we swap the CPUs logically, by modifying the logical/physical CPU mapping.
This has two major drawbacks: First the change is visible from user space (e.g.
CPU sysfs files) and second it is hard to ensure that nowhere in the kernel
the physical CPU ID is stored before suspend.
To fix this, we now really swap the physical CPUs, if the resume CPU is not
the pysical suspend CPU. We restart the suspend CPU and stop the resume CPU
using SIGP restart and SIGP stop. If the suspend CPU is no longer available,
we write a message and load a disabled wait PSW.
Signed-off-by: Michael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The DASD device driver reads the feature codes of a device during
device initialization. These codes are later used to determine the
availability of advanced features like PAV or High Performance FICON.
Some very old devices do not support the command to read feature
codes and the initialization routine fails.
As the feature codes are not necessary for basic DASD operations, we
can support such devices by just ignoring missing feature codes.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Devices are no longer removed or added in the suspend and resume
callbacks. Instead they are marked unregistered in suspend. In the
resume callback the ap_scan_bus method is scheduled. The bus scan
function will remove the old device and add new ones. This way all
the device handling will be done in only one function. Additionaly
the case where the domain might change during suspend/resume is
caught. In that case the devices qid needs to re-calculated in
order of having it found by the scan method.
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
pfn_is_nosave doesn't return the correct value for the second lowcore
page if lowcore protection is enabled. Make sure it always returns
the correct value.
While at it simplify the whole thing.
NSS special handling is done by the tprot check like it already works
for DCSS as well. So remove the extra code for NSS.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Removes a couple of simple code duplications. But before I have to do
this again, just simplify it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch_ptrace on s390 implements PTRACE_(PEEK|POKE)(TEXT|DATA) instead of
using using ptrace_request in kernel/ptrace.c.
The only reason is the 31bit addressing mode, where we have to unmask the
highest bit.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The disabled_wait inline assmembly also clobbers register r1, but it
is missing in the clobber list.
Fixes recursive Oops on panic.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make the inline assembly look like all others.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
