Commit Graph

51 Commits

Author SHA1 Message Date
Tao Ma
757055adc5 ocfs2/xattr: Only set buffer update if it doesn't exist in cache.
When we call ocfs2_init_xattr_bucket, we deem that the new buffer head
will be written to disk immediately, so we just use sb_getblk. But in
some cases the buffer may have already been in ocfs2 uptodate cache,
so we only call ocfs2_set_buffer_uptodate if the buffer head isn't
in the cache.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:18 -08:00
Tao Ma
1c32a2fd46 ocfs2/xattr: Remove additional bucket allocation in bucket defragment.
Joel has refactored xattr bucket and make xattr bucket a general
wrapper. So in ocfs2_defrag_xattr_bucket, we have already passed the
bucket in, so there is no need to allocate a new one and read it.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:18 -08:00
Joel Becker
02dbf38d19 ocfs2: Use buckets in ocfs2_xattr_set_entry_in_bucket().
The ocfs2_xattr_set_entry_in_bucket() function is already working on an
ocfs2_xattr_bucket structure, so let's use the bucket API.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:18 -08:00
Joel Becker
161d6f30f1 ocfs2: Use buckets in ocfs2_defrag_xattr_bucket().
Use the ocfs2_xattr_bucket abstraction for reading and writing the
bucket in ocfs2_defrag_xattr_bucket().

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:18 -08:00
Joel Becker
178eeac354 ocfs2: Use buckets in ocfs2_xattr_create_index_block().
Use the ocfs2_xattr_bucket abstraction in
ocfs2_xattr_create_index_block() and its helpers.  We get more efficient
reads, a lot less buffer_head munging, and nicer code to boot.  While
we're at it, ocfs2_xattr_update_xattr_search() becomes void.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:18 -08:00
Joel Becker
e2356a3f02 ocfs2: Use buckets in ocfs2_xattr_bucket_find().
Change the ocfs2_xattr_bucket_find() function to use ocfs2_xattr_bucket
as its abstraction.  This makes for more efficient reads, as buckets are
linear blocks, and also has improved caching characteristics.  It also
reads better.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:17 -08:00
Joel Becker
ba93712759 ocfs2: Take ocfs2_xattr_bucket structures off of the stack.
The ocfs2_xattr_bucket structure is a nice abstraction, but it is a bit
large to have on the stack.  Just like ocfs2_path, let's allocate it
with a ocfs2_xattr_bucket_new() function.

We can now store the inode on the bucket, cleaning up all the other
bucket functions.  While we're here, we catch another place or two that
wasn't using ocfs2_read_xattr_bucket().

Updates:
- No longer allocating xis.bucket, as it will never be used.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:17 -08:00
Joel Becker
4980c6daba ocfs2: Copy xattr buckets with a dedicated function.
Now that the places that copy whole buckets are using struct
ocfs2_xattr_bucket, we can do the copy in a dedicated function.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:17 -08:00
Joel Becker
1224be020f ocfs2: Wrap journal_access/journal_dirty for xattr buckets.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:17 -08:00
Joel Becker
784b816a91 ocfs2: Improve ocfs2_read_xattr_bucket().
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:17 -08:00
Joel Becker
6dde41d9e7 ocfs2: Provide a wrapper to brelse() xattr bucket buffers.
A common theme is walking all the buffer heads on an ocfs2_xattr_bucket
and releasing them.  Let's wrap that.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:17 -08:00
Joel Becker
3e6329463e ocfs2: Convenient access to an xattr bucket's header.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:16 -08:00
Joel Becker
51def39f0c ocfs2: Convenient access to xattr bucket data blocks.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:16 -08:00
Joel Becker
9c7759aa67 ocfs2: Convenient access to an xattr bucket's block number.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:16 -08:00
Joel Becker
4ac6032d6c ocfs2: Field prefixes for the xattr_bucket structure
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:34:16 -08:00
Tao Ma
83099bc647 ocfs2: Always update xattr search when creating bucket.
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-12-16 14:07:37 -08:00
Tiger Yang
6c1e183e12 ocfs2: Check search result in ocfs2_xattr_block_get()
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: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:47 -08:00
Mark Fasheh
de29c08528 ocfs2: fix printk related build warnings in xattr.c
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:47 -08:00
Tao Ma
80bcaf3469 ocfs2/xattr: Proper hash collision handle in bucket division
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: Tao Ma <tao.ma@oracle.com>
Cc: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:47 -08:00
Tao Ma
d32647993c ocfs2: Fix check of return value of ocfs2_start_trans() in xattr.c.
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: Tao Ma <tao.ma@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:47 -08:00
Tao Ma
63fd775737 ocfs2: Remove unused ocfs2_restore_xattr_block().
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:46 -08:00
Joel Becker
54f443f4e7 ocfs2: Don't repeat ocfs2_xattr_block_find()
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:46 -08:00
Joel Becker
eb6ff2397d ocfs2: Specify appropriate journal access for new xattr buckets.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:46 -08:00
Joel Becker
bd60bd37ad ocfs2: Check errors from ocfs2_xattr_update_xattr_search()
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:45 -08:00
Joel Becker
b37c4d84e9 ocfs2: Don't return -EFAULT from a corrupt xattr entry.
If the xattr disk structures are corrupt, return -EIO, not -EFAULT.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:45 -08:00
Joel Becker
f6087fb799 ocfs2: Check xattr block signatures properly.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:44 -08:00
Tiger Yang
c988fd045f ocfs2: add handler_map array bounds checking
Make the handler_map array as large as the possible value range to avoid
a fencepost error.

[ Utilize alternate method -- Joel ]

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:44 -08:00
Tiger Yang
ceb1eba3dc ocfs2: remove duplicate definition in xattr
Include/linux/xattr.h already has the definition about xattr prefix,
so remove the duplicate definitions in xattr.c.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:44 -08:00
Tiger Yang
0030e00150 ocfs2: fix function declaration and definition in xattr
Because we merged the xattr sources into one file, some functions
no longer belong in the header file.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:44 -08:00
Tiger Yang
c3cb682735 ocfs2: fix license in xattr
This patch fixes the license in xattr.c and xattr.h.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-11-10 09:51:43 -08:00
Mark Fasheh
1efd47f873 ocfs2: fix build error
I merged the latest ocfs2_read_blocks() changes in xattr.c wrong. This makes
Ocfs2 compile again.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-14 18:31:46 -07:00
Joel Becker
0fcaa56a2a ocfs2: Simplify ocfs2_read_block()
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-14 11:51:57 -07:00
Joel Becker
31d33073ca ocfs2: Require an inode for ocfs2_read_block(s)().
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-14 11:43:29 -07:00
Tao Ma
936b883436 ocfs2: Refactor xattr list and remove ocfs2_xattr_handler().
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 17:02:45 -07:00
Tao Ma
2057e5c678 ocfs2: Calculate EA hash only by its suffix.
According to Christoph Hellwig's advice, the hash value of EA
is only calculated by its suffix.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 17:02:44 -07:00
Mark Fasheh
99219aea68 ocfs2: Move trusted and user attribute support into xattr.c
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: Mark Fasheh <mfasheh@suse.com>
2008-10-13 17:02:44 -07:00
Mark Fasheh
40daa16a34 ocfs2: Uninline ocfs2_xattr_name_hash()
This is too big to be inlined.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 17:02:44 -07:00
Tao Ma
5a09561199 ocfs2: Add empty bucket support in xattr.
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 17:02:43 -07:00
Tao Ma
06b240d8af ocfs2/xattr.c: Fix a bug when inserting xattr.
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 17:02:43 -07:00
Tao Ma
08413899db ocfs2: Resolve deadlock in ocfs2_xattr_free_block.
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:06 -07:00
Tao Ma
28b8ca0b7f ocfs2: bug-fix for journal extend in xattr.
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:06 -07:00
Joel Becker
8d6220d6a7 ocfs2: Change ocfs2_get_*_extent_tree() to ocfs2_init_*_extent_tree()
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:05 -07:00
Joel Becker
f99b9b7ccf ocfs2: Make ocfs2_extent_tree the first-class representation of a tree.
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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:05 -07:00
Mark Fasheh
ff1ec20ef6 ocfs2: fix printk format warnings
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: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:03 -07:00
Tiger Yang
8154da3d21 ocfs2: Add incompatible flag for extended attribute
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: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:03 -07:00
Tao Ma
a394425643 ocfs2: Delete all xattr buckets during inode removal
In inode removal, we need to iterate all the buckets, remove any
externally-stored EA values and delete the xattr buckets.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:03 -07:00
Tao Ma
012255961c ocfs2: Enable xattr set in index btree
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:03 -07:00
Tao Ma
589dc2602f ocfs2: Add xattr lookup code xattr btrees
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: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:03 -07:00
Tao Ma
0c044f0b24 ocfs2: Add xattr bucket iteration for large numbers of EAs
Ocfs2 breaks up xattr index tree leaves into 4k regions, called buckets.
Attributes are stored within a given bucket, depending on hash value.

After a discussion with Mark, we decided that the per-bucket index
(xe_entry[]) would only exist in the 1st block of a bucket. Likewise,
name/value pairs will not straddle more than one block. This allows the
majority of operations to work directly on the buffer heads in a leaf block.

This patch adds code to iterate the buckets in an EA. A new abstration of
ocfs2_xattr_bucket is added. It records the bhs in this bucket and
ocfs2_xattr_header. This keeps the code neat, improving readibility.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:03 -07:00
Tiger Yang
cf1d6c763f ocfs2: Add extended attribute support
This patch implements storing extended attributes both in inode or a single
external block. We only store EA's in-inode when blocksize > 512 or that
inode block has free space for it. When an EA's value is larger than 80
bytes, we will store the value via b-tree outside inode or block.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13 16:57:02 -07:00