This is done to differentiate between using and not using controld and
use the connection information accordingly.
We need to be backward compatible. So, we use a new enum
ocfs2_connection_type to identify when controld is used and when it is
not.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is an effort of removing ocfs2_controld.pcmk and getting ocfs2 DLM
handling up to the times with respect to DLM (>=4.0.1) and corosync
(2.3.x). AFAIK, cman also is being phased out for a unified corosync
cluster stack.
fs/dlm performs all the functions with respect to fencing and node
management and provides the API's to do so for ocfs2. For all future
references, DLM stands for fs/dlm code.
The advantages are:
+ No need to run an additional userspace daemon (ocfs2_controld)
+ No controld device handling and controld protocol
+ Shifting responsibilities of node management to DLM layer
For backward compatibility, we are keeping the controld handling code.
Once enough time has passed we can remove a significant portion of the
code. This was tested by using the kernel with changes on older
unmodified tools. The kernel used ocfs2_controld as expected, and
displayed the appropriate warning message.
This feature requires modification in the userspace ocfs2-tools. The
changes can be found at: https://github.com/goldwynr/ocfs2-tools branch:
nocontrold Currently, not many checks are present in the userspace code,
but that would change soon.
This patch (of 6):
Add clustername to cluster connection.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.
[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the retry-based AIO infrastructure now that nothing in tree
is using it.
We want to remove retry-based AIO because it is fundemantally unsafe.
It retries IO submission from a kernel thread that has only assumed the
mm of the submitting task. All other task_struct references in the IO
submission path will see the kernel thread, not the submitting task.
This design flaw means that nothing of any meaningful complexity can use
retry-based AIO.
This removes all the code and data associated with the retry machinery.
The most significant benefit of this is the removal of the locking
around the unused run list in the submission path.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull user namespace and namespace infrastructure changes from Eric W Biederman:
"This set of changes starts with a few small enhnacements to the user
namespace. reboot support, allowing more arbitrary mappings, and
support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
user namespace root.
I do my best to document that if you care about limiting your
unprivileged users that when you have the user namespace support
enabled you will need to enable memory control groups.
There is a minor bug fix to prevent overflowing the stack if someone
creates way too many user namespaces.
The bulk of the changes are a continuation of the kuid/kgid push down
work through the filesystems. These changes make using uids and gids
typesafe which ensures that these filesystems are safe to use when
multiple user namespaces are in use. The filesystems converted for
3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs. The
changes for these filesystems were a little more involved so I split
the changes into smaller hopefully obviously correct changes.
XFS is the only filesystem that remains. I was hoping I could get
that in this release so that user namespace support would be enabled
with an allyesconfig or an allmodconfig but it looks like the xfs
changes need another couple of days before it they are ready."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
cifs: Enable building with user namespaces enabled.
cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
cifs: Convert struct cifs_sb_info to use kuids and kgids
cifs: Modify struct smb_vol to use kuids and kgids
cifs: Convert struct cifsFileInfo to use a kuid
cifs: Convert struct cifs_fattr to use kuid and kgids
cifs: Convert struct tcon_link to use a kuid.
cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
cifs: Convert from a kuid before printing current_fsuid
cifs: Use kuids and kgids SID to uid/gid mapping
cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
cifs: Override unmappable incoming uids and gids
nfsd: Enable building with user namespaces enabled.
nfsd: Properly compare and initialize kuids and kgids
nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
nfsd: Modify nfsd4_cb_sec to use kuids and kgids
nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
nfsd: Convert nfsxdr to use kuids and kgids
nfsd: Convert nfs3xdr to use kuids and kgids
...
If lockres refresh failed, the super lock will never be released which
will cause some processes on other cluster nodes hung forever.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert between uid and gids stored in the on the wire format of dlm
locks aka struct ocfs2_meta_lvb and kuids and kgids stored in
inode->i_uid and inode->i_gid.
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When ocfs2dc thread holds dc_task_lock spinlock and receives soft IRQ it
deadlock itself trying to get same spinlock in ocfs2_wake_downconvert_thread.
Below is the stack snippet.
The patch disables interrupts when acquiring dc_task_lock spinlock.
ocfs2_wake_downconvert_thread
ocfs2_rw_unlock
ocfs2_dio_end_io
dio_complete
.....
bio_endio
req_bio_endio
....
scsi_io_completion
blk_done_softirq
__do_softirq
do_softirq
irq_exit
do_IRQ
ocfs2_downconvert_thread
[kthread]
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (31 commits)
ocfs2: avoid unaligned access to dqc_bitmap
ocfs2: Use filemap_write_and_wait() instead of write_inode_now()
ocfs2: honor O_(D)SYNC flag in fallocate
ocfs2: Add a missing journal credit in ocfs2_link_credits() -v2
ocfs2: send correct UUID to cleancache initialization
ocfs2: Commit transactions in error cases -v2
ocfs2: make direntry invalid when deleting it
fs/ocfs2/dlm/dlmlock.c: free kmem_cache_zalloc'd data using kmem_cache_free
ocfs2: Avoid livelock in ocfs2_readpage()
ocfs2: serialize unaligned aio
ocfs2: Implement llseek()
ocfs2: Fix ocfs2_page_mkwrite()
ocfs2: Add comment about orphan scanning
ocfs2: Clean up messages in the fs
ocfs2/cluster: Cluster up now includes network connections too
ocfs2/cluster: Add new function o2net_fill_node_map()
ocfs2/cluster: Fix output in file elapsed_time_in_ms
ocfs2/dlm: dlmlock_remote() needs to account for remastery
ocfs2/dlm: Take inflight reference count for remotely mastered resources too
ocfs2/dlm: Cleanup dlm_wait_for_node_death() and dlm_wait_for_node_recovery()
...
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
ocfs2 cannot currently mount a device that is readonly at the media
("hard readonly"). Fix the broken places.
see detail: http://oss.oracle.com/bugzilla/show_bug.cgi?id=1322
[ Description edited -- Joel ]
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Reviewed-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
mlog_exit is used to record the exit status of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.
This patch just try to remove it or change it. So:
1. if all the error paths already use mlog_errno, it is just removed.
Otherwise, it will be replaced by mlog_errno.
2. if it is used to print some return value, it is replaced with
mlog(0,...).
mlog_exit_ptr is changed to mlog(0.
All those mlog(0,...) will be replaced with trace events later.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
ENTRY is used to record the entry of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.
So for mlog_entry_void, we just remove it.
for mlog_entry(...), we replace it with mlog(0,...), and they
will be replace by trace event later.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Patch makes use of the hrtimer to track times in ocfs2 lock stats.
The patch is a bit involved to ensure no additional impact on the memory
footprint. The size of ocfs2_inode_cache remains 1280 bytes on 32-bit systems.
A related change was to modify the unit of the max wait time from nanosec to
microsec allowing us to track max time larger than 4 secs. This change
necessitated the bumping of the output version in the debugfs file,
locking_state, from 2 to 3.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
Track negative dentries by recording the generation number of the parent
directory in d_fsdata. The generation number for the parent directory is
recorded in the inode_info, which increments every time the lock on the
directory is dropped.
If the generation number of the parent directory and the negative dentry
matches, there is no need to perform the revalidate, else a revalidate
is forced. This improves performance in situations where nodes look for
the same non-existent file multiple times.
Thanks Mark for explaining the DLM sequence.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The position of global quota file info does not change. So we do not have
to do logical -> physical block translation every time we reread it from
disk. Thus we can also avoid taking ip_alloc_sem.
Acked-by: Joel Becker <Joel.Becker@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This patch adds a new masklog and uses it allow tracing ASTs and BASTs
in the dlmglue layer. This has been found to be very useful in debugging
cluster locking issues.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Inside the stackglue, the locking protocol structure is hanging off of
the ocfs2_cluster_connection. This takes it one further; the locking
protocol is passed into ocfs2_cluster_connect(). Now different cluster
connections can have different locking protocols with distinct asts.
Note that all locking protocols have to keep their maximum protocol
version in lock-step.
With the protocol structure set in ocfs2_cluster_connect(), there is no
need for the stackglue to have a static pointer to a specific protocol
structure. We can change initialization to only pass in the maximum
protocol version.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We're going to want it in the ast functions, so we convert union
ocfs2_dlm_lksb to struct ocfs2_dlm_lksb and let it carry the connection.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The stackglue ast and bast functions tried to maintain the fiction that
their arguments were void pointers. In reality, stack_user.c had to
know that the argument was an ocfs2_lock_res in order to get the status
off of the lksb. That's ugly.
This changes stackglue to always pass the lksb as the argument to ast
and bast functions. The caller can always use container_of() to get the
ocfs2_lock_res or user_dlm_lock_res. The net effect to the caller is
zero. They still get back the lockres in their ast. stackglue gets
cleaner, and now can use the lksb itself.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch plugs a race between the downconvert thread and an unlock ast message.
Specifically, after the downconvert worker has done its task, the dc thread needs
to check whether an unlock ast made the downconvert moot.
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@sus.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
During blocked lock processing, we should consider the possibility that the
lock is no longer blocking.
Joel Becker <joel.becker@oracle.com> assisted in fixing this issue.
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
During upconvert, if the master were to send a BAST, dlmglue will detect the
upconversion in process and send a cancel convert to the master. Upon receiving
the AST for the cancel convert, it will re-process the lock resource to determine
whether it needs downconverting. Say, the up was from PR to EX and the BAST was
for EX. After the cancel convert, it will need to downconvert to NL.
However, if the node was originally upconverting from NL to EX, then there would
be no reason to downconvert (assuming the same message sequence).
This patch makes dlmglue consider the possibility that the current lock level
is already compatible and that downconverting is not required.
Joel Becker <joel.becker@oracle.com> assisted in fixing this issue.
Fixes ossbz#1178
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1178
Reported-by: Coly Li <coly.li@suse.de>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
There is possibility of a livelock in __ocfs2_cluster_lock(). If a node were
to get an ast for an upconvert request, followed immediately by a bast,
there is a small window where the fs may downconvert the lock before the
process requesting the upconvert is able to take the lock.
This patch adds a new flag to indicate that the upconvert is still in
progress and that the dc thread should not downconvert it right now.
Wengang Wang <wen.gang.wang@oracle.com> and Joel Becker
<joel.becker@oracle.com> contributed heavily to this patch.
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
During bast, set the OCFS2_LOCK_BLOCKED flag only if the lock needs to
downconverted.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Acked-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This patch adds the missed mlog_exit() and mlog_exit_void() lines when routines
return.
Signed-off-by: Coly Li <coly.li@suse.de>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@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>
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: Joel 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: Joel Becker <joel.becker@oracle.com>
Add lockdep support to OCFS2. The support also covers all of the cluster
locks except for open locks, journal locks, and local quotafile locks. These
are special because they are acquired for a node, not for a particular process
and lockdep cannot deal with such type of locking.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Local and Hard-RO mounts do not need orphan scanning.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We don't access the LVB in our ocfs2_*_lock_res_init() functions.
Since the LVB can become invalid during some cluster recovery
operations, the dlmglue must be able to handle an uninitialized
LVB.
For the orphan scan lock, we initialized an uninitialzed LVB with our
scan sequence number plus one. This starts a normal orphan scan
cycle.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The Lock Value Block (LVB) of a DLM lock can be lost when nodes die and
the DLM cannot reconstruct its state. Clients of the DLM need to know
this.
ocfs2's internal DLM, o2dlm, explicitly zeroes out the LVB when it loses
track of the state. This is not a standard behavior, but ocfs2 has
always relied on it. Thus, an o2dlm LVB is always "valid".
ocfs2 now supports both o2dlm and fs/dlm via the stack glue. When
fs/dlm loses track of an LVBs state, it sets a flag
(DLM_SBF_VALNOTVALID) on the Lock Status Block (LKSB). The contents of
the LVB may be garbage or merely stale.
ocfs2 doesn't want to try to guess at the validity of the stale LVB.
Instead, it should be checking the VALNOTVALID flag. As this is the
'standard' way of treating LVBs, we will promote this behavior.
We add a stack glue API ocfs2_dlm_lvb_valid(). It returns non-zero when
the LVB is valid. o2dlm will always return valid, while fs/dlm will
check VALNOTVALID.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
When a dentry is unlinked, the unlinking node takes an EX on the dentry lock
before moving the dentry to the orphan directory. Other nodes that have
this dentry in cache have a PR on the same dentry lock. When the EX is
requested, the other nodes flag the corresponding inode as MAYBE_ORPHANED
during downconvert. The inode is finally deleted when the last node to iput
the inode sees that i_nlink==0 and the MAYBE_ORPHANED flag is set.
A problem arises if a node is forced to free dentry locks because of memory
pressure. If this happens, the node will no longer get downconvert
notifications for the dentries that have been unlinked on another node.
If it also happens that node is actively using the corresponding inode and
happens to be the one performing the last iput on that inode, it will fail
to delete the inode as it will not have the MAYBE_ORPHANED flag set.
This patch fixes this shortcoming by introducing a periodic scan of the
orphan directories to delete such inodes. Care has been taken to distribute
the workload across the cluster so that no one node has to perform the task
all the time.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
For nfs exporting, ocfs2_get_dentry() returns the dentry for fh.
ocfs2_get_dentry() may read from disk when the inode is not in memory,
without any cross cluster lock. this leads to the file system loading a
stale inode.
This patch fixes above problem.
Solution is that in case of inode is not in memory, we get the cluster
lock(PR) of alloc inode where the inode in question is allocated from (this
causes node on which deletion is done sync the alloc inode) before reading
out the inode itsself. then we check the bitmap in the group (the inode in
question allcated from) to see if the bit is clear. if it's clear then it's
stale. if the bit is set, we then check generation as the existing code
does.
We have to read out the inode in question from disk first to know its alloc
slot and allot bit. And if its not stale we read it out using ocfs2_iget().
The second read should then be from cache.
And also we have to add a per superblock nfs_sync_lock to cover the lock for
alloc inode and that for inode in question. this is because ocfs2_get_dentry()
and ocfs2_delete_inode() lock on them in reverse order. nfs_sync_lock is locked
in EX mode in ocfs2_get_dentry() and in PR mode in ocfs2_delete_inode(). so
that mutliple ocfs2_delete_inode() can run concurrently in normal case.
[mfasheh@suse.com: build warning fixes and comment cleanups]
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The dentry lock has a different format than other locks. This patch fixes
ocfs2_log_dlm_error() macro to make it print the dentry lock correctly.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
When two nodes holding PR locks on a resource concurrently attempt to
upconvert the locks to EX, the master sends a BAST to one of the nodes. This
message tells that node to first cancel convert the upconvert request,
followed by downconvert to a NL. Only when this lock is downconverted to NL,
can the master upconvert the first node's lock to EX.
While the fs was doing the cancel convert, it was forgetting to wake up the
dc thread after a successful cancel, leading to a deadlock.
Reported-and-Tested-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
When I review ocfs2 code, find there are 2 typos to "successfull". After
doing grep "successfull " in kernel tree, 22 typos found totally -- great
minds always think alike :)
This patch fixes all the similar typos. Thanks for Randy's ack and comments.
Signed-off-by: Coly Li <coyli@suse.de>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dlmglue.c has lots of code which casts the return value of ocfs2_dlm_lvb().
This is pointless however, as ocfs2_dlm_lvb() returns void *.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2_bread() has become ocfs2_read_virt_blocks(), with a prototype to
match ocfs2_read_blocks(). The quota code, converting from
ocfs2_bread(), wraps the call to ocfs2_read_virt_blocks() in
ocfs2_read_quota_block(). Unfortunately, the prototype of
ocfs2_read_quota_block() matches the old prototype of ocfs2_bread().
The problem is that ocfs2_bread() returned the buffer head, and callers
assumed that a NULL pointer was indicative of error. It wasn't. This
is why ocfs2_bread() took an int*err argument as well.
The new prototype of ocfs2_read_virt_blocks() avoids this error handling
confusion. Let's change ocfs2_read_quota_block() to match.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
For each quota type each node has local quota file. In this file it stores
changes users have made to disk usage via this node. Once in a while this
information is synced to global file (and thus with other nodes) so that
limits enforcement at least aproximately works.
Global quota files contain all the information about usage and limits. It's
mostly handled by the generic VFS code (which implements a trie of structures
inside a quota file). We only have to provide functions to convert structures
from on-disk format to in-memory one. We also have to provide wrappers for
various quota functions starting transactions and acquiring necessary cluster
locks before the actual IO is really started.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The ocfs2 code currently reads inodes off disk with a simple
ocfs2_read_block() call. Each place that does this has a different set
of sanity checks it performs. Some check only the signature. A couple
validate the block number (the block read vs di->i_blkno). A couple
others check for VALID_FL. Only one place validates i_fs_generation. A
couple check nothing. Even when an error is found, they don't all do
the same thing.
We wrap inode reading into ocfs2_read_inode_block(). This will validate
all the above fields, going readonly if they are invalid (they never
should be). ocfs2_read_inode_block_full() is provided for the places
that want to pass read_block flags. Every caller is passing a struct
inode with a valid ip_blkno, so we don't need a separate blkno argument
either.
We will remove the validation checks from the rest of the code in a
later commit, as they are no longer necessary.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In ocfs2_unlock_ast(), call wake_up() on lockres before releasing
the spin lock on it. As soon as the spin lock is released, the
lockres can be freed.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mark 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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark 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: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Fix printk format warnings when OCFS2_FS_STATS=n:
linux-next-20080528/fs/ocfs2/dlmglue.c: In function 'ocfs2_dlm_seq_show':
linux-next-20080528/fs/ocfs2/dlmglue.c:2623: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type 'int'
linux-next-20080528/fs/ocfs2/dlmglue.c:2623: warning: format '%llu' expects type 'long long unsigned int', but argument 4 has type 'int'
linux-next-20080528/fs/ocfs2/dlmglue.c:2623: warning: format '%llu' expects type 'long long unsigned int', but argument 7 has type 'int'
linux-next-20080528/fs/ocfs2/dlmglue.c:2623: warning: format '%llu' expects type 'long long unsigned int', but argument 8 has type 'int'
Signed-off-by: Randy Dunlap <randy.dunlap@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>
The stack-glue merge changed the way we use flags in dlmglue in that we now
use the fs/dlm equivalents. Unfortunately, a merge error left the new flock
code only partially updated. This took a while to show up though, because
the lock level constants are actually identical between o2dlm and fs/dlm.
The *_CONVERT and *_NOQUEUE flags have different values though, which is
eventually causing a crash in flags_to_o2dlm().
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Userspace can now query and specify the cluster stack in use via the
/sys/fs/ocfs2/cluster_stack file. By default, it is 'o2cb', which is
the classic stack. Thus, old tools that do not know how to modify this
file will work just fine. The stack cannot be modified if there is a
live filesystem.
ocfs2_cluster_connect() now takes the expected cluster stack as an
argument. This way, the filesystem and the stack glue ensure they are
speaking to the same backend.
If the stack is 'o2cb', the o2cb stack plugin is used. For any other
value, the fsdlm stack plugin is selected.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
We define the ocfs2_stack_plugin structure to represent a stack driver.
The o2cb stack code is split into stack_o2cb.c. This becomes the
ocfs2_stack_o2cb.ko module.
The stackglue generic functions are similarly split into the
ocfs2_stackglue.ko module. This module now provides an interface to
register drivers. The ocfs2_stack_o2cb driver registers itself. As
part of this interface, ocfs2_stackglue can load drivers on demand.
This is accomplished in ocfs2_cluster_connect().
ocfs2_cluster_disconnect() is now notified when a _hangup() is pending.
If a hangup is pending, it will not release the driver module and will
let _hangup() do that.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The stack glue initialization function needs a better name so that it can be
used cleanly when stackglue becomes a module.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
dlmglue.c was still referencing a raw o2dlm lksb in one instance. Let's
create a generic ocfs2_dlm_dump_lksb() function. This allows underlying
DLMs to print whatever they want about their lock.
We then move the o2dlm dump into stackglue.c where it belongs.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
When using fsdlm, -EAGAIN is returned in the async callback for NOQUEUE
requests. Fix up dlmglue to expect this.
Signed-off-by: David Teigland <teigland@redhat.com>
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>
It doesn't make sense to query for a node number before connecting to the
cluster stack. This should be safe to do because node_num is only just
printed,
and we're actually only moving the setting of node num a small amount
further in the mount process.
[ Disconnect when node query fails -- Joel ]
Reviewed-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>
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>
Change the ocfs2_dlm_lock/unlock() functions to return -errno values.
This is the first step towards elminiating dlm_status in
fs/ocfs2/dlmglue.c. The change also passes -errno values to
->unlock_ast().
[ Fix a return code in dlmglue.c and change the error translation table into
an array of ints. --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The ocfs2 generic code should use the values in <linux/dlmconstants.h>.
stackglue.c will convert them to o2dlm values.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This is the first in a series of patches to isolate ocfs2 from the
underlying cluster stack. Here we wrap the dlm locking functions with
ocfs2-specific calls. Because ocfs2 always uses the same dlm lock status
callbacks, we can eliminate the callbacks from the filesystem visible
functions.
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>
journal.c and dlmglue.c would refresh the slot map by hand. Instead, have
the update and clear functions do the work inside slot_map.c. The eventual
result is to make ocfs2_slot_info defined privately in slot_map.c
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch makes the needlessly global ocfs2_downconvert_thread()
static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This patch contains the following cleanups that are now possible:
- make the following needlessly global functions static:
- dlmglue.c:ocfs2_process_blocked_lock()
- heartbeat.c:ocfs2_node_map_init()
- #if 0 the following unused global function plus support functions:
- heartbeat.c:ocfs2_node_map_is_only()
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Commit f1f540688e "optimized"
ocfs2_data_convert_worker() to "only do work for regular files".
Unfortunately, I left out a '!', which casued it to *skip* regular files.
This was hidden from testing until recently because the default data
journaling mode (data=ordered) doesn't exercise this code.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
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>
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>
Call this the "inode_lock" now, since it covers both data and meta data.
This patch makes no functional changes.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The meta lock now covers both meta data and data, so this just removes the
now-redundant data lock.
Combining locks saves us a round of lock mastery per inode and one less lock
to ping between nodes during read/write.
We don't lose much - since meta locks were always held before a data lock
(and at the same level) ordered writeout mode (the default) ensured that
flushing for the meta data lock also pushed out data anyways.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
In order to extend inode lock coverage to inode data, we use the same data
downconvert worker with only a small modification to only do work for
regular files.
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>
If we have not yet created a cluster lock, ocfs2_cluster_lock() will
first create it at NLMODE, and then convert the lock to either PRMODE or
EXMODE (whichever is requested).
Change ocfs2_cluster_lock() to just create the lock at the initially
requested level. ocfs2_locking_ast() handles this case fine, so the only
update required was in setup of locking state. This should reduce the number
of network messages required for a new lock by one, providing an incremental
performance enhancement.
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>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes the following needlessly global functions static:
- aops.c: ocfs2_write_data_page()
- dlmglue.c: ocfs2_dump_meta_lvb_info()
- file.c: ocfs2_set_inode_size()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The extent map code was ripped out earlier because of an inability to deal
with holes. This patch adds back a simpler caching scheme requiring far less
code.
Our old extent map caching was designed back when meta data block caching in
Ocfs2 didn't work very well, resulting in many disk reads. These days our
metadata caching is much better, resulting in no un-necessary disk reads. As
a result, extent caching doesn't have to be as fancy, nor does it have to
cache as many extents. Keeping the last 3 extents seen should be sufficient
to give us a small performance boost on some streaming workloads.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Older file systems which didn't support holes did a dumb calculation of
i_blocks based on i_size. This is no longer accurate, so fix things up to
take actual allocation into account.
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>
Ocfs2 currently does cluster-wide node messaging to check the open state of
an inode during delete. This patch removes that mechanism in favor of an
inode cluster lock which is taken at shared read when an inode is first read
and dropped in clear_inode(). This allows a deleting node to test the
liveness of an inode by attempting to take an exclusive lock.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
We don't want the extent map and uptodate cache destruction in
ocfs2_meta_lock_update() on a local mount, so skip that.
This fixes several bugs with uptodate being cleared on buffers and extent
maps being corrupted.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Mmap-heavy clustered workloads were sometimes finding stale data on mmap
reads. The solution is to call unmap_mapping_range() on any down convert of
a data lock.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This allows users to format an ocfs2 file system with a special flag,
OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT. When the file system sees this flag, it
will not use any cluster services, nor will it require a cluster
configuration, thus acting like a 'local' file system.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This patch adds the core routines for updating atime in ocfs2.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This gets us rid of a slab we no longer need, as well as removing the
majority of what's left on ocfs2_journal_handle.
ocfs2_commit_unstarted_handle() has no more real work to do, so remove that
function too.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This patch makes the needlessly global ocfs2_create_new_lock() static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86. (It would be more on an x86_64 system). This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).
This patch:
The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer. Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer. This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.
[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With this, we don't need to pass an additional struct with function pointer.
Now that the callbacks are fully used, comment the remaining API.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Goldwyn Rodrigues