ocfs2_xattr_set_in_bucket() doesn't need to do its own hacky space
checking.  Let's let ocfs2_xa_prepare_entry() (via ocfs2_xa_set()) do
the more accurate work.  Whenever it doesn't have space,
ocfs2_xattr_set_in_bucket() can try to get more space.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

ocfs2_xa_set() wraps the ocfs2_xa_prepare_entry()/ocfs2_xa_store_value()
logic.  Both callers can now use the same routine.  ocfs2_xa_remove()
moves directly into ocfs2_xa_set().
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

ocfs2_xa_prepare_entry() gets all the logic to add, remove, or modify
external value trees.  Now, when it exits, the entry is ready to receive
a value of any size.

ocfs2_xa_remove() is added to handle the complete removal of an entry.
It truncates the external value tree before calling
ocfs2_xa_remove_entry().

ocfs2_xa_store_inline_value() becomes ocfs2_xa_store_value().  It can
store any value.

ocfs2_xattr_set_entry() loses all the allocation logic and just uses
these functions.  ocfs2_xattr_set_value_outside() disappears.

ocfs2_xattr_set_in_bucket() uses these functions and makes
ocfs2_xattr_set_entry_in_bucket() obsolete.  That goes away, as does
ocfs2_xattr_bucket_set_value_outside() and
ocfs2_xattr_bucket_value_truncate().
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

We're going to want to make sure our buffers get accessed and dirtied
correctly.  So have the xa_loc do the work.  This includes storing the
inode on ocfs2_xa_loc.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

We use the ocfs2_xattr_value_buf structure to manage external values.
It lets the value tree code do its work regardless of the containing
storage.  ocfs2_xa_fill_value_buf() initializes a value buf from an
ocfs2_xa_loc entry.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Previously the xattr code would send in a fake value, containing a tree
root, to the function that installed name+value pairs.  Instead, we pass
the real value to ocfs2_xa_set_inline_value(), and it notices that the
value cannot fit.  Thus, it installs a tree root.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

We create two new functions on ocfs2_xa_loc, ocfs2_xa_prepare_entry()
and ocfs2_xa_store_inline_value().

ocfs2_xa_prepare_entry() makes sure that the xl_entry field of
ocfs2_xa_loc is ready to receive an xattr.  The entry will point to an
appropriately sized name+value region in storage.  If an existing entry
can be reused, it will be.  If no entry already exists, it will be
allocated.  If there isn't space to allocate it, -ENOSPC will be
returned.

ocfs2_xa_store_inline_value() stores the data that goes into the 'value'
part of the name+value pair.  For values that don't fit directly, this
stores the value tree root.

A number of operations are added to ocfs2_xa_loc_operations to support
these functions.  This reflects the disparate behaviors of xattr blocks
and buckets.

With these functions, the overlapping ocfs2_xattr_set_entry_local() and
ocfs2_xattr_set_entry_normal() can be replaced with a single call
scheme.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

An ocfs2 xattr entry stores the text name and value as a pair in the
storage area.  Obviously names and values can be variable-sized.  If a
value is too large for the entry storage, a tree root is stored instead.
The name+value pair is also padded.

Because of this, there are a million places in the code that do:

	if (needs_external_tree(value_size)
		namevalue_size = pad(name_size) + tree_root_size;
	else
		namevalue_size = pad(name_size) + pad(value_size);

Let's create some convenience functions to make the code more readable.
There are three forms.  The first takes the raw sizes.  The second takes
an ocfs2_xattr_info structure.  The third takes an existing
ocfs2_xattr_entry.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Rather than calculating strlen all over the place, let's store the
name length directly on ocfs2_xattr_info.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

struct ocfs2_xattr_info is a useful structure describing an xattr
you'd like to set.  Let's put prefixes on the member fields so it's
easier to read and use.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Add ocfs2_xa_remove_entry(), which will remove an xattr entry from its
storage via the ocfs2_xa_loc descriptor.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

The ocfs2 extended attribute (xattr) code is very flexible.  It can
store xattrs in the inode itself, in an external block, or in a tree of
data structures.  This allows the number of xattrs to be bounded by the
filesystem size.

However, the code that manages each possible storage location is
different.  Maintaining the ocfs2 xattr code requires changing each hunk
separately.

This patch is the start of a series introducing the ocfs2_xa_loc
structure.  This structure wraps the on-disk details of an xattr
entry.  The goal is that the generic xattr routines can use
ocfs2_xa_loc without knowing the underlying storage location.

This first pass merely implements the basic structure, initializing it,
and wiping the name+value pair of the entry.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch add extent block (metadata) stealing mechanism for
extent allocation. This mechanism is same as the inode stealing.
if no room in slot specific extent_alloc, we will try to
allocate extent block from the next slot.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Acked-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

In ocfs2_value_metas_in_xattr_header, we should Use
le16_to_cpu for ocfs2_extent_list.l_next_free_rec.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Add a flags argument to struct xattr_handler and pass it to all xattr
handler methods.  This allows using the same methods for multiple
handlers, e.g. for the ACL methods which perform exactly the same action
for the access and default ACLs, just using a different underlying
attribute.  With a little more groundwork it'll also allow sharing the
methods for the regular user/trusted/secure handlers in extN, ocfs2 and
jffs2 like it's already done for xfs in this patch.

Also change the inode argument to the handlers to a dentry to allow
using the handlers mechnism for filesystems that require it later,
e.g. cifs.

[with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJames Morris <jmorris@namei.org>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

To become consistent with filesystems such as XFS or BTRFS, make posix
ACLs always available. This also reduces possibility of
misconfiguration on admin's side.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

reflink has 2 options for the destination file:
1. snapshot: reflink will attempt to preserve ownership, permissions,
   and all other security state in order to create a full snapshot.
2. new file: it will acquire the data extent sharing but will see the
   file's security state and attributes initialized as a new file.

So add the option to ocfs2.
Signed-off-by: NTao 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: NTao Ma <tao.ma@oracle.com>

Signed-off-by: NTao 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: NTao 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: NTao 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: NTao 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: NTao Ma <tao.ma@oracle.com>

In xattr reflink, we also need to create xattr block, so
abstract the process out.
Signed-off-by: NTao Ma <tao.ma@oracle.com>

In ocfs2_xattr_bucket_get_name_value, actually we only use
super_block. So use it.
Signed-off-by: NTao 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: NTao 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: NTao Ma <tao.ma@oracle.com>

With this commit, extent tree operations are divorced from inodes and
rely on ocfs2_caching_info.  Phew!
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

One more generic btree function that is isolated from struct inode.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

One more function that doesn't need a struct inode to pass to its
children.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

One more function down, no inode in the entire insert-extent chain.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

ocfs2_find_path and ocfs2_find_leaf() walk our btrees, reading extent
blocks.  They need struct ocfs2_caching_info for that, but not struct
inode.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

The next step in divorcing metadata I/O management from struct inode is
to pass struct ocfs2_caching_info to the journal functions.  Thus the
journal locks a metadata cache with the cache io_lock function.  It also
can compare ci_last_trans and ci_created_trans directly.

This is a large patch because of all the places we change
ocfs2_journal_access..(handle, inode, ...) to
ocfs2_journal_access..(handle, INODE_CACHE(inode), ...).
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

We are really passing the inode into the ocfs2_read/write_blocks()
functions to get at the metadata cache.  This commit passes the cache
directly into the metadata block functions, divorcing them from the
inode.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

gcc 4.4.1 generates the following build warning on i386:

CC [M]  fs/ocfs2/xattr.o
fs/ocfs2/xattr.c: In function ‘ocfs2_xattr_block_get’:
fs/ocfs2/xattr.c:1055: warning: ‘block_off’ may be used uninitialized in this function

The following fix is based on a similar approach by David Howells
few days back: http://lkml.org/lkml/2009/7/9/109,

Signed-off-by: Subrata Modak<subrata@linux.vnet.ibm.com>,
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Currently the kernel defines XATTR_LIST_MAX as 65536
in include/linux/limits.h.  This is the largest buffer that is used for
listing xattrs.

But with ocfs2 xattr tree, we actually have no limit for the number.  If
filesystem has more names than can fit in the buffer, the kernel
logs will be pollluted with something like this when listing:

(27738,0):ocfs2_iterate_xattr_buckets:3158 ERROR: status = -34
(27738,0):ocfs2_xattr_tree_list_index_block:3264 ERROR: status = -34

So don't print "ERROR" message as this is not an ocfs2 error.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch makes use of Ocfs2's flexible btree code to add an additional
tree to directory inodes. The new tree stores an array of small,
fixed-length records in each leaf block. Each record stores a hash value,
and pointer to a block in the traditional (unindexed) directory tree where a
dirent with the given name hash resides. Lookup exclusively uses this tree
to find dirents, thus providing us with constant time name lookups.

Some of the hashing code was copied from ext3. Unfortunately, it has lots of
unfixed checkpatch errors. I left that as-is so that tracking changes would
be easier.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>
Acked-by: NJoel Becker <joel.becker@oracle.com>

A long time ago, xs->base is allocated a 4K size and all the contents
in the bucket are copied to the it. Now we use ocfs2_xattr_bucket to
abstract xattr bucket and xs->base is initialized to the start of the
bu_bhs[0]. So xs->base + offset will overflow when the value root is
stored outside the first block.

Then why we can survive the xattr test by now? It is because we always
read the bucket contiguously now and kernel mm allocate continguous
memory for us. We are lucky, but we should fix it. So just get the
right value root as other callers do.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

If this is a new directory with inline data, we choose to
reserve the entire inline area for directory contents and
force an external xattr block.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This patch set a gap (4 bytes) between xattr entry and
name/value when xattr in bucket. This gap use to seperate
entry and name/value when a bucket is full. It had already
been set when xattr in inode/block.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>