A common action is to call ocfs2_journal_access() and
ocfs2_journal_dirty() on the buffer heads of an xattr bucket.  Let's
create nice wrappers.

While we're there, let's drop the places that try to be smart by writing
only the first and last blocks of a bucket.  A bucket is contiguous, so
writing the whole thing is actually more efficient.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The ocfs2_read_xattr_bucket() function would read an xattr bucket into a
list of buffer heads.  However, we have a nice ocfs2_xattr_bucket
structure.  Let's have it fill that out instead.

In addition, ocfs2_read_xattr_bucket() would initialize buffer heads for
a bucket that's never been on disk before.  That's confusing.  Let's
call that functionality ocfs2_init_xattr_bucket().

The functions ocfs2_cp_xattr_bucket() and ocfs2_half_xattr_bucket() are
updated to use the ocfs2_xattr_bucket structure rather than raw bh
lists.  That way they can use the new read/init calls.  In addition,
they drop the wasted read of an existing target bucket.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

A common theme is walking all the buffer heads on an ocfs2_xattr_bucket
and releasing them.  Let's wrap that.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The xattr code often wants to access the ocfs2_xattr_header at the start
of an bucket.  Rather than walk the pointer chains, let's just create
another nice macro.  As a side benefit, we can get rid of the mostly
spurious ->bu_xh element on the bucket structure.  The idea is ripped
from the ocfs2_path code.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The xattr code often wants to access the data pointer for blocks in an
xattr bucket.  This is usually found by dereferencing the bh array
hanging off of the ocfs2_xattr_bucket structure.  Rather than do this
all the time, let's provide a nice little macro.  The idea is ripped
from the ocfs2_path code.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The xattr code often wants to know the block number of an xattr bucket.
This is usually found by dereferencing the first bh hanging off of the
ocfs2_xattr_bucket structure.  Rather than do this all the time, let's
provide a nice little macro.  The idea is ripped from the ocfs2_path
code.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The ocfs2_xattr_bucket structure keeps track of the buffers for one
xattr bucket.  Let's prefix the fields for easier code navigation.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

When we create xattr bucket during the process of xattr set, we always
need to update the ocfs2_xattr_search since even if the bucket size is
the same as block size, the offset will change because of the removal
of the ocfs2_xattr_block header.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

ocfs2_xattr_block_get() calls ocfs2_xattr_search() to find an external
xattr, but doesn't check the search result that is passed back via struct
ocfs2_xattr_search. Add a check for search result, and pass back -ENODATA if
the xattr search failed. This avoids a later NULL pointer error.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Signed-off-by: NMark Fasheh <mfasheh@suse.com>

In ocfs2/xattr, we must make sure the xattrs which have the same hash value
exist in the same bucket so that the search schema can work. But in the old
implementation, when we want to extend a bucket, we just move half number of
xattrs to the new bucket. This works in most cases, but if we are lucky
enough we will move 2 xattrs into 2 different buckets. This means that an
xattr from the previous bucket cannot be found anymore. This patch fix this
problem by finding the right position during extending the bucket and extend
an empty bucket if needed.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Cc: Joel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

On failure, ocfs2_start_trans() returns values like ERR_PTR(-ENOMEM),
so we should check whether handle is NULL. Fix them to use IS_ERR().
Jan has made the patch for other part in ocfs2(thank Jan for it), so
this is just the fix for fs/ocfs2/xattr.c.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Since now ocfs2 supports empty xattr buckets, we will never remove
the xattr index tree even if all the xattrs are removed, so this
function will never be called. So remove it.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

ocfs2_xattr_block_get() looks up the xattr in a startlingly familiar
way; it's identical to the function ocfs2_xattr_block_find().  Let's just
use the later in the former.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

There are a couple places that get an xattr bucket that may be reading
an existing one or may be allocating a new one.  They should specify the
correct journal access mode depending.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The ocfs2_xattr_update_xattr_search() function can return an error when
trying to read blocks off of disk.  The caller needs to check this error
before using those (possibly invalid) blocks.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

If the xattr disk structures are corrupt, return -EIO, not -EFAULT.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The xattr.c code is currently memcmp()ing naking buffer pointers.
Create the OCFS2_IS_VALID_XATTR_BLOCK() macro to match its peers and use
that.

In addition, failed signature checks were returning -EFAULT, which is
completely wrong.  Return -EIO.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Make the handler_map array as large as the possible value range to avoid
a fencepost error.

[ Utilize alternate method -- Joel ]
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Include/linux/xattr.h already has the definition about xattr prefix,
so remove the duplicate definitions in xattr.c.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Because we merged the xattr sources into one file, some functions
no longer belong in the header file.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This patch fixes the license in xattr.c and xattr.h.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

I merged the latest ocfs2_read_blocks() changes in xattr.c wrong. This makes
Ocfs2 compile again.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

More than 30 callers of ocfs2_read_block() pass exactly OCFS2_BH_CACHED.
Only six pass a different flag set.  Rather than have every caller care,
let's make ocfs2_read_block() take no flags and always do a cached read.
The remaining six places can call ocfs2_read_blocks() directly.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Now that synchronous readers are using ocfs2_read_blocks_sync(), all
callers of ocfs2_read_blocks() are passing an inode.  Use it
unconditionally.  Since it's there, we don't need to pass the
ocfs2_super either.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

According to Christoph Hellwig's advice, we really don't need
a ->list to handle one xattr's list. Just a map from index to
xattr prefix is enough. And I also refactor the old list method
with the reference from fs/xfs/linux-2.6/xfs_xattr.c and the
xattr list method in btrfs.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

According to Christoph Hellwig's advice, the hash value of EA
is only calculated by its suffix.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Per Christoph Hellwig's suggestion - don't split these up. It's not like we
gained much by having the two tiny files around.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This is too big to be inlined.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

As Mark mentioned, it may be time-consuming when we remove the
empty xattr bucket, so this patch try to let empty bucket exist
in xattr operation. The modification includes:
1. Remove the functin of bucket and extent record deletion during
   xattr delete.
2. In xattr set:
   1) Don't clean the last entry so that if the bucket is empty,
      the hash value of the bucket is the hash value of the entry
      which is deleted last.
   2) During insert, if we meet with an empty bucket, just use the
      1st entry.
3. In binary search of xattr bucket, use the bucket hash value(which
   stored in the 1st xattr entry) to find the right place.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

During the process of xatt insertion, we use binary search
to find the right place and "low" is set to it. But when
there is one xattr which has the same name hash as the inserted
one, low is the wrong value. So set it to the right position.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

In ocfs2_xattr_free_block, we take a cluster lock on xb_alloc_inode while we
have a transaction open. This will deadlock the downconvert thread, so fix
it.

We can clean up how xattr blocks are removed while here - this patch also
moves the mechanism of releasing xattr block (including both value, xattr
tree and xattr block) into this function.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

In ocfs2_extend_trans, when we can't extend the current
transaction, it will commit current transaction and restart
a new one. So if the previous credits we have allocated aren't
used(the block isn't dirtied before our extend), we will not
have enough credits for any future operation(it will cause jbd
complain and bug out). So check this and re-extend it.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The original get/put_extent_tree() functions held a reference on
et_root_bh.  However, every single caller already has a safe reference,
making the get/put cycle irrelevant.

We change ocfs2_get_*_extent_tree() to ocfs2_init_*_extent_tree().  It
no longer gets a reference on et_root_bh.  ocfs2_put_extent_tree() is
removed.  Callers now have a simpler init+use pattern.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

We now have three different kinds of extent trees in ocfs2: inode data
(dinode), extended attributes (xattr_tree), and extended attribute
values (xattr_value).  There is a nice abstraction for them,
ocfs2_extent_tree, but it is hidden in alloc.c.  All the calling
functions have to pick amongst a varied API and pass in type bits and
often extraneous pointers.

A better way is to make ocfs2_extent_tree a first-class object.
Everyone converts their object to an ocfs2_extent_tree() via the
ocfs2_get_*_extent_tree() calls, then uses the ocfs2_extent_tree for all
tree calls to alloc.c.

This simplifies a lot of callers, making for readability.  It also
provides an easy way to add additional extent tree types, as they only
need to be defined in alloc.c with a ocfs2_get_<new>_extent_tree()
function.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This patch fixes the following build warnings:

fs/ocfs2/xattr.c: In function 'ocfs2_half_xattr_bucket':
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 7 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 8 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 7 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 8 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 7 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 8 has type 'long int'
fs/ocfs2/xattr.c: In function 'ocfs2_xattr_set_entry_in_bucket':
fs/ocfs2/xattr.c:4092: warning: format '%d' expects type 'int', but argument 6 has type 'size_t'
fs/ocfs2/xattr.c:4092: warning: format '%d' expects type 'int', but argument 6 has type 'size_t'
fs/ocfs2/xattr.c:4092: warning: format '%d' expects type 'int', but argument 6 has type 'size_t'
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This patch adds the s_incompat flag for extended attribute support. This
helps us ensure that older versions of Ocfs2 or ocfs2-tools will not be able
to mount a volume with xattr support.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

In inode removal, we need to iterate all the buckets, remove any
externally-stored EA values and delete the xattr buckets.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Where the previous patches added the ability of list/get xattr in buckets
for ocfs2, this patch enables ocfs2 to store large numbers of EAs.

The original design doc is written by Mark Fasheh, and it can be found in
http://oss.oracle.com/osswiki/OCFS2/DesignDocs/IndexedEATrees. I only had to
make small modifications to it.

First, because the bucket size is 4K, a new field named xh_free_start is added
in ocfs2_xattr_header to indicate the next valid name/value offset in a bucket.
It is used when we store new EA name/value. With this field, we can find the
place more quickly and what's more, we don't need to sort the name/value every
time to let the last entry indicate the next unused space. This makes the
insert operation more efficient for blocksizes smaller than 4k.

Because of the new xh_free_start, another field named as xh_name_value_len is
also added in ocfs2_xattr_header. It records the total length of all the
name/values in the bucket. We need this so that we can check it and defragment
the bucket if there is not enough contiguous free space.

An xattr insertion looks like this:
1. xattr_index_block_find: find the right bucket by the name_hash, say bucketA.
2. check whether there is enough space in bucketA. If yes, insert it directly
   and modify xh_free_start and xh_name_value_len accordingly. If not, check
   xh_name_value_len to see whether we can store this by defragment the bucket.
   If yes, defragment it and go on insertion.
3. If defragement doesn't work, check whether there is new empty bucket in
   the clusters within this extent record. If yes, init the new bucket and move
   all the buckets after bucketA one by one to the next bucket. Move half of the
   entries in bucketA to the next bucket and go on insertion.
4. If there is no new bucket, grow the extent tree.

As for xattr deletion, we will delete an xattr bucket when all it's xattrs
are removed and move all the buckets after it to the previous one. When all
the xattr buckets in an extend record are freed, free this extend records
from ocfs2_xattr_tree.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Add code to lookup a given extended attribute in the xattr btree. Lookup
follows this general scheme:

1. Use ocfs2_xattr_get_rec to find the xattr extent record

2. Find the xattr bucket within the extent which may contain this xattr

3. Iterate the bucket to find the xattr. In ocfs2_xattr_block_get(), we need
   to recalcuate the block offset and name offset for the right position of
   name/value.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>