Dropping of last reference to dentry lock is a complicated operation involving
dropping of reference to inode. This can get complicated and quota code in
particular needs to obtain some quota locks which leads to potential deadlock.
Thus we defer dropping of inode reference to ocfs2_wq.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Future ocfs2 features metaecc and indexed directories need to store a
little bit of data in each dirblock. For compatibility, we place this
in a trailer at the end of the dirblock. The trailer plays itself as an
empty dirent, so that if the features are turned off, it can be reused
without requiring a tunefs scan.
This code adds the trailer and validates it when the block is read in.
[ Mark is the original author, but I reinserted this code before his
dir index work. -- Joel ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The per-metadata-type ocfs2_journal_access_*() functions hook up jbd2
commit triggers and allow us to compute metadata ecc right before the
buffers are written out. This commit provides ecc for inodes, extent
blocks, group descriptors, and quota blocks. It is not safe to use
extened attributes and metaecc at the same time yet.
The ocfs2_extent_tree and ocfs2_path abstractions in alloc.c both hide
the type of block at their root. Before, it didn't matter, but now the
root block must use the appropriate ocfs2_journal_access_*() function.
To keep this abstract, the structures now have a pointer to the matching
journal_access function and a wrapper call to call it.
A few places use naked ocfs2_write_block() calls instead of adding the
blocks to the journal. We make sure to calculate their checksum and ecc
before the write.
Since we pass around the journal_access functions. Let's typedef them
in ocfs2.h.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This is the code that computes crc32 and ecc for ocfs2 metadata blocks.
There are high-level functions that check whether the filesystem has the
ecc feature, mid-level functions that work on a single block or array of
buffer_heads, and the low-level ecc hamming code that can handle
multiple buffers like crc32_le().
It's not hooked up to the filesystem yet.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Enable quota usage tracking on mount and disable it on umount. Also
add support for quota on and quota off quotactls and usrquota and
grpquota mount options. Add quota features among supported ones.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Implement functions for recovery after a crash. Functions just
read local quota file and sync info to global quota file.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
We weren't consistently checking extent blocks after we read them.
Most places checked the signature, but none checked h_blkno or
h_fs_signature. Create a toplevel ocfs2_read_extent_block() that does
the read and the validation.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Random places in the code would check a group descriptor bh to see if it
was valid. The previous commit unified descriptor block reads,
validating all block reads in the same place. Thus, these checks are no
longer necessary. Rather than eliminate them, however, we change them
to BUG_ON() checks. This ensures the assumptions remain true. All of
the code paths to these checks have been audited to ensure they come
from a validated descriptor read.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Random places in the code would check a dinode bh to see if it was
valid. Not only did they do different levels of validation, they
handled errors in different ways.
The previous commit unified inode block reads, validating all block
reads in the same place. Thus, these haphazard checks are no longer
necessary. Rather than eliminate them, however, we change them to
BUG_ON() checks. This ensures the assumptions remain true. All of the
code paths to these checks have been audited to ensure they come from a
validated inode read.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch adds POSIX ACL(access control lists) APIs in ocfs2. We convert
struct posix_acl to many ocfs2_acl_entry and regard them as an extended
attribute entry.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark 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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2 wants JBD2 for many reasons, not the least of which is that JBD is
limiting our maximum filesystem size.
It's a pretty trivial change. Most functions are just renamed. The
only functional change is moving to Jan's inode-based ordered data mode.
It's better, too.
Because JBD2 reads and writes JBD journals, this is compatible with any
existing filesystem. It can even interact with JBD-based ocfs2 as long
as the journal is formated for JBD.
We provide a compatibility option so that paranoid people can still use
JBD for the time being. This will go away shortly.
[ Moved call of ocfs2_begin_ordered_truncate() from ocfs2_delete_inode() to
ocfs2_truncate_for_delete(). --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Now that ocfs2 limits inode numbers to 32bits, add a mount option to
disable the limit. This parallels XFS. 64bit systems can handle the
larger inode numbers.
[ Added description of inode64 mount option in ocfs2.txt. --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark 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: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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>
Add the structures and helper functions we want for handling inline extended
attributes. We also update the inline-data handlers so that they properly
function in the event that we have both inline data and inline attributes
sharing an inode block.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
A per-mount debugfs file, "local_alloc" is created which when read will
expose live state of the nodes local alloc file. Performance impact is
minimal, only a bit of memory overhead per mount point. Still, the code is
hidden behind CONFIG_OCFS2_FS_STATS. This feature will help us debug
local alloc performance problems on a live system.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Ocfs2's local allocator disables itself for the duration of a mount point
when it has trouble allocating a large enough area from the primary bitmap.
That can cause performance problems, especially for disks which were only
temporarily full or fragmented. This patch allows for the allocator to
shrink it's window first, before being disabled. Later, it can also be
re-enabled so that any performance drop is minimized.
To do this, we allow the value of osb->local_alloc_bits to be shrunk when
needed. The default value is recorded in a mostly read-only variable so that
we can re-initialize when required.
Locking had to be updated so that we could protect changes to
local_alloc_bits. Mostly this involves protecting various local alloc values
with the osb spinlock. A new state is also added, OCFS2_LA_THROTTLED, which
is used when the local allocator is has shrunk, but is not disabled. If the
available space dips below 1 megabyte, the local alloc file is disabled. In
either case, local alloc is re-enabled 30 seconds after the event, or when
an appropriate amount of bits is seen in the primary bitmap.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Do this instead of tracking absolute local alloc size. This avoids
needless re-calculatiion of bits from bytes in localalloc.c. Additionally,
the value is now in a more natural unit for internal file system bitmap
work.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
As the fs recovery is asynchronous, there is a small chance that another
node can mount (and thus recover) the slot before the recovery thread
gets to it.
If this happens, the recovery thread will block indefinitely on the
journal/slot lock as that lock will be held for the duration of the mount
(by design) by the node assigned to that slot.
The solution implemented is to keep track of the journal replays using
a recovery generation in the journal inode, which will be incremented by the
thread replaying that journal. The recovery thread, before attempting the
blocking lock on the journal/slot lock, will compare the generation on disk
with what it has cached and skip recovery if it does not match.
This bug appears to have been inadvertently introduced during the mount/umount
vote removal by mainline commit 34d024f843. In the
mount voting scheme, the messaging would indirectly indicate that the slot
was being recovered.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch adds code to track the number of times the fs takes
various cluster locks as well as the times associated with it.
The information is made available to users via debugfs.
This patch was originally written by Jan Kara <jack@suse.cz>.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Inode allocation is modified to look in other nodes allocators during
extreme out of space situations. We retry our own slot when space is freed
back to the global bitmap, or whenever we've allocated more than 1024 inodes
from another slot.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The filesystem gains the USERSPACE_STACK incomat bit and the
s_cluster_info field on the superblock. When a userspace stack is in
use, the name of the stack is stored on-disk for mount-time
verification.
The "cluster_stack" option is added to mount(2) processing. The mount
process needs to pass the matching stack name. If the passed name and
the on-disk name do not match, the mount is failed.
When using the classic o2cb stack, the incompat bit is *not* set and no
mount option is used other than the usual heartbeat=local. Thus, the
filesystem is compatible with older tools.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
o2dlm has the non-standard behavior of providing a cancel callback
(unlock_ast) even when the cancel has failed (the locking operation
succeeded without canceling). This is called CANCELGRANT after the
status code sent to the callback. fs/dlm does not provide this
callback, so dlmglue must be changed to live without it.
o2dlm_unlock_ast_wrapper() in stackglue now ignores CANCELGRANT calls.
Because dlmglue no longer sees CANCELGRANT, ocfs2_unlock_ast() no longer
needs to check for it. ocfs2_locking_ast() must catch that a cancel was
tried and clear the cancel state.
Making these changes opens up a locking race. dlmglue uses the the
OCFS2_LOCK_BUSY flag to ensure only one thread is calling the dlm at any
one time. But dlmglue must unlock the lockres before calling into the
dlm. In the small window of time between unlocking the lockres and
calling the dlm, the downconvert thread can try to cancel the lock. The
downconvert thread is checking the OCFS2_LOCK_BUSY flag - it doesn't
know that ocfs2_dlm_lock() has not yet been called.
Because ocfs2_dlm_lock() has not yet been called, the cancel operation
will just be a no-op. There's nothing to cancel. With CANCELGRANT,
dlmglue uses the CANCELGRANT callback to clear up the cancel state.
When it comes around again, it will retry the cancel. Eventually, the
first thread will have called into ocfs2_dlm_lock(), and either the
lock or the cancel will succeed. The downconvert thread can then do its
downconvert.
Without CANCELGRANT, there is nothing to clean up the cancellation
state. The downconvert thread does not know to retry its operations.
More importantly, the original lock may be blocking on the other node
that is trying to cancel us. With neither able to make progress, the
ast is never called and the cancellation state is never cleaned up that
way. dlmglue is deadlocked.
The OCFS2_LOCK_PENDING flag is introduced to remedy this window. It is
set at the same time OCFS2_LOCK_BUSY is. Thus, the downconvert thread
can check whether the lock is cancelable. If not, it just loops around
to try again. Once ocfs2_dlm_lock() is called, the thread then clears
OCFS2_LOCK_PENDING and wakes the downconvert thread. Now, if the
downconvert thread finds the lock BUSY, it can safely try to cancel it.
Whether the cancel works or not, the state will be properly set and the
lock processing can continue.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The last bit of classic stack used directly in ocfs2 code is o2hb.
Specifically, the check for heartbeat during mount and the call to
ocfs2_hb_ctl during unmount.
We create an extra API, ocfs2_cluster_hangup(), to encapsulate the call
to ocfs2_hb_ctl. Other stacks will just leave hangup() empty.
The check for heartbeat is moved into ocfs2_cluster_connect(). It will
be matched by a similar check for other stacks.
With this change, only stackglue.c includes cluster/ headers.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2 asks the cluster stack for the local node's node number for two
reasons; to fill the slot map and to print it. While the slot map isn't
necessary for userspace cluster stacks, the printing is very nice for
debugging. Thus we add ocfs2_cluster_this_node() as a generic API to get
this value. It is anticipated that the slot map will not be used under a
userspace cluster stack, so validity checks of the node num only need to
exist in the slot map code. Otherwise, it just gets used and printed as an
opaque value.
[ Fixed up some "int" versus "unsigned int" issues and made osb->node_num
truly opaque. --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This step introduces a cluster stack agnostic API for initializing and
exiting. fs/ocfs2/dlmglue.c no longer uses o2cb/o2dlm knowledge to
connect to the stack. It is all handled in stackglue.c.
heartbeat.c no longer needs to know how it gets called.
ocfs2_do_node_down() is now a clean recovery trigger.
The big gotcha is the ordering of initializations and de-initializations done
underneath ocfs2_cluster_connect(). ocfs2_dlm_init() used to do all
o2dlm initialization in one block. Thus, the o2dlm functionality of
ocfs2_cluster_connect() is very straightforward. ocfs2_dlm_shutdown(),
however, did a few things between de-registration of the eviction
callback and actually shutting down the domain. Now de-registration and
shutdown of the domain are wrapped within the single
ocfs2_cluster_disconnect() call. I've checked the code paths to make
sure we can safely tear down things in ocfs2_dlm_shutdown() before
calling ocfs2_cluster_disconnect(). The filesystem has already set
itself to ignore the callback.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Wrap the lock status block (lksb) in a union. Later we will add a union
element for the fs/dlm lksb. Create accessors for the status and lvb
fields.
Other than a debugging function, dlmglue.c does not directly reference
the o2dlm locking path anymore.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The old slot map had a few limitations:
- It was limited to one block, so the maximum slot count was 255.
- Each slot was signed 16bits, limiting node numbers to INT16_MAX.
- An empty slot was marked by the magic 0xFFFF (-1).
The new slot map format provides 32bit node numbers (UINT32_MAX), a
separate space to mark a slot in use, and extra room to grow. The slot
map is now bounded by i_size, not a block.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The in-memory slot map uses the same magic as the on-disk one. There is
a special value to mark a slot as invalid. It relies on the size of
certain types and so on.
Write a new in-memory map that keeps validity as a separate field. Outside
of the I/O functions, OCFS2_INVALID_SLOT now means what it is supposed to.
It also is no longer tied to the type size.
This also means that only the I/O functions refer to 16bit quantities.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The old recovery map was a bitmap of node numbers. This was sufficient
for the maximum node number of 254. Going forward, we want node numbers
to be UINT32. Thus, we need a new recovery map.
Note that we can't keep track of slots here. We must write down the
node number to recovery *before* we get the locks needed to convert a
node number into a slot number.
The recovery map is now an array of unsigned ints, max_slots in size.
It moves to journal.c with the rest of recovery.
Because it needs to be initialized, we move all of recovery initialization
into a new function, ocfs2_recovery_init(). This actually cleans up
ocfs2_initialize_super() a little as well. Following on, recovery cleaup
becomes part of ocfs2_recovery_exit().
A number of node map functions are rendered obsolete and are removed.
Finally, waiting on recovery is wrapped in a function rather than naked
checks on the recovery_event. This is a cleanup from Mark.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Just use osb_lock around the ocfs2_slot_info data. This allows us to
take the ocfs2_slot_info structure private in slot_info.c. All access
is now via accessors.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patchset moves le*_add_cpu and be*_add_cpu functions from OCFS2 to core
header (1st), converts ext3 filesystem to this API (2nd) and replaces XFS
different named functions with new ones (3rd).
There are many places where these functions will be useful. Just look at:
grep -r 'cpu_to_[ble12346]*([ble12346]*_to_cpu.*[-+]' linux-src/ Patch for
ext3 is an example how conversions will probably look like.
This patch:
- move inline functions which add native byte order variable to
little/big endian variable to core header
* le16_add_cpu(__le16 *var, u16 val)
* le32_add_cpu(__le32 *var, u32 val)
* le64_add_cpu(__le64 *var, u64 val)
* be32_add_cpu(__be32 *var, u32 val)
- add for completeness:
* be16_add_cpu(__be16 *var, u16 val)
* be64_add_cpu(__be64 *var, u64 val)
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, when ocfs2 nodes connect via TCP, they advertise their
compatibility level. If the versions do not match, two nodes cannot speak
to each other and they disconnect. As a result, this provides no forward or
backwards compatibility.
This patch implements a simple protocol negotiation at the dlm level by
introducing a major/minor version number scheme for entities that
communicate. Specifically, o2dlm has a major/minor version for interaction
with o2dlm on other nodes, and ocfs2 itself has a major/minor version for
interacting with the filesystem on other nodes.
This will allow rolling upgrades of ocfs2 clusters when changes to the
locking or network protocols can be done in a backwards compatible manner.
In those cases, only the minor number is changed and the negotatied protocol
minor is returned from dlm join. In the far less likely event that a
required protocol change makes backwards compatibility impossible, we simply
bump the major number.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
ocfs2_super->blocked_lock_list and ocfs2_super->blocked_lock_count have some
usage restrictions which aren't immediately obvious to anyone reading the
code. It's a good idea to document this so that we avoid making costly
mistakes in the future.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Hook up ocfs2_flock(), using the new flock lock type in dlmglue.c. A new
mount option, "localflocks" is added so that users can revert to old
functionality as need be.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This adds a new dlmglue lock type which is intended to back flock()
requests.
Since these locks are driven from userspace, usage rules are much more
liberal than the typical Ocfs2 internal cluster lock. As a result, we can't
make use of most dlmglue features - lock caching and lock level
optimizations in particular. Additionally, userspace is free to deadlock
itself, so we have to deal with that in the same way as the rest of the
kernel - by allowing a signal to abort a lock request.
In order to keep ocfs2_cluster_lock() complexity down, ocfs2_file_lock()
does it's own dlm coordination. We still use the same helper functions
though, so duplicated code is kept to a minimum.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Local alloc is a performance optimization in ocfs2 in which a node
takes a window of bits from the global bitmap and then uses that for
all small local allocations. This window size is fixed to 8MB currently.
This patch allows users to specify the window size in MB including
disabling it by passing in 0. If the number specified is too large,
the fs will use the default value of 8MB.
mount -o localalloc=X /dev/sdX /mntpoint
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Mostly taken from ext3. This allows the user to set the jbd commit interval,
in seconds. The default of 5 seconds stays the same, but now users can
easily increase the commit interval. Typically, this would be increased in
order to benefit performance at the expense of data-safety.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The node maps that are set/unset by these votes are no longer relevant, thus
we can remove the mount and umount votes. Since those are the last two
remaining votes, we can also remove the entire vote infrastructure.
The vote thread has been renamed to the downconvert thread, and the small
amount of functionality related to managing it has been moved into
fs/ocfs2/dlmglue.c. All references to votes have been removed or updated.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Add the disk, network and memory structures needed to support data in inode.
Struct ocfs2_inline_data is defined and embedded in ocfs2_dinode for storing
inline data.
A new inode field, i_dyn_features, is added to facilitate tracking of
dynamic inode state. Since it will be used often, we want to mirror it on
ocfs2_inode_info, and transfer it via the meta data lvb.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>
ocfs2_align_clusters_to_page_index() needs to cast the clusters shift to
pgoff_t and ocfs2_file_buffered_write() needs loff_t when calculating
destination start for memcpy.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Writes to a region marked as unwritten might result in a record split or
merge. We can support splits by making minor changes to the existing insert
code. Merges require left rotations which mostly re-use right rotation
support functions.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
ocfs2 will attempt to assign the node the slot# provided in the mount
option. Failure to assign the preferred slot is not an error. This small
feature can be useful for automated testing.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Since we don't zero on extend anymore, truncate needs to be fixed up to zero
the part of a file between i_size and and end of it's cluster. Otherwise a
subsequent extend could expose bad data.
This introduced a new helper, which can be used in ocfs2_write().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Unfortunately, ocfs2 can no longer make use of generic_file_aio_write_nlock()
because allocating writes will require zeroing of pages adjacent to the I/O
for cluster sizes greater than page size.
Implement a custom file write here, which can order page locks for zeroing.
This also has the advantage that cluster locks can easily be ordered outside
of the page locks.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The code in extent_map.c is not prepared to deal with a subtree being
rotated between lookups. This can happen when filling holes in sparse files.
Instead of a lengthy patch to update the code (which would likely lose the
benefit of caching subtree roots), we remove most of the algorithms and
implement a simple path based lookup. A less ambitious extent caching scheme
will be added in a later patch.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Introduce tree rotations into the b-tree code. This will allow ocfs2 to
support sparse files. Much of the added code is designed to be generic (in
the ocfs2 sense) so that it can later be re-used to implement large
extended attributes.
This patch only adds the rotation code and does minimal updates to callers
of the extent api.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Jan Kara