Provide a mechanism for higher levels to create CUI/CUD items, submit
them to the log, and a stub function to deal with recovered CUI items.
These parts will be connected to the refcountbt in a later patch.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Nothing ever uses the extent array in the rmap update done redo
item, so remove it before it is fixed in the on-disk log format.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

When we map, unmap, or convert an extent in a file's data or attr
fork, schedule a respective update in the rmapbt.  Previous versions
of this patch required a 1:1 correspondence between bmap and rmap,
but this is no longer true as we now have ability to make interval
queries against the rmapbt.

We use the deferred operations code to handle redo operations
atomically and deadlock free.  This plumbs in all five rmap actions
(map, unmap, convert extent, alloc, free); we'll use the first three
now for file data, and reflink will want the last two.  We also add
an error injection site to test log recovery.

Finally, we need to fix the bmap shift extent code to adjust the
rmaps correctly.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Connect the xfs_defer mechanism with the pieces that we'll need to
handle deferred rmap updates.  We'll wire up the existing code to
our new deferred mechanism later.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Provide a mechanism for higher levels to create RUI/RUD items, submit
them to the log, and a stub function to deal with recovered RUI items.
These parts will be connected to the rmapbt in a later patch.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

For the rmap btree to work, we have to feed the extent owner
information to the the allocation and freeing functions. This
information is what will end up in the rmap btree that tracks
allocated extents. While we technically don't need the owner
information when freeing extents, passing it allows us to validate
that the extent we are removing from the rmap btree actually
belonged to the owner we expected it to belong to.

We also define a special set of owner values for internal metadata
that would otherwise have no owner. This allows us to tell the
difference between metadata owned by different per-ag btrees, as
well as static fs metadata (e.g. AG headers) and internal journal
blocks.

There are also a couple of special cases we need to take care of -
during EFI recovery, we don't actually know who the original owner
was, so we need to pass a wildcard to indicate that we aren't
checking the owner for validity. We also need special handling in
growfs, as we "free" the space in the last AG when extending it, but
because it's new space it has no actual owner...

While touching the xfs_bmap_add_free() function, re-order the
parameters to put the struct xfs_mount first.

Extend the owner field to include both the owner type and some sort
of index within the owner.  The index field will be used to support
reverse mappings when reflink is enabled.

When we're freeing extents from an EFI, we don't have the owner
information available (rmap updates have their own redo items).
xfs_free_extent therefore doesn't need to do an rmap update. Make
sure that the log replay code signals this correctly.

This is based upon a patch originally from Dave Chinner. It has been
extended to add more owner information with the intent of helping
recovery operations when things go wrong (e.g. offset of user data
block in a file).

[dchinner: de-shout the xfs_rmap_*_owner helpers]
[darrick: minor style fixes suggested by Christoph Hellwig]
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Drop the compatibility shims that we were using to integrate the new
deferred operation mechanism into the existing code.  No new code.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Connect the xfs_defer mechanism with the pieces that we'll need to
handle deferred extent freeing.  We'll wire up the existing code to
our new deferred mechanism later.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Replace structure typedefs with struct xfs_foo_* in the EFI/EFD
handling code in preparation to move it over to deferred ops.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

One of the problems we currently have with delayed logging is that
under serious memory pressure we can deadlock memory reclaim. THis
occurs when memory reclaim (such as run by kswapd) is reclaiming XFS
inodes and issues a log force to unpin inodes that are dirty in the
CIL.

The CIL is pushed, but this will only occur once it gets the CIL
context lock to ensure that all committing transactions are complete
and no new transactions start being committed to the CIL while the
push switches to a new context.

The deadlock occurs when the CIL context lock is held by a
committing process that is doing memory allocation for log vector
buffers, and that allocation is then blocked on memory reclaim
making progress. Memory reclaim, however, is blocked waiting for
a log force to make progress, and so we effectively deadlock at this
point.

To solve this problem, we have to move the CIL log vector buffer
allocation outside of the context lock so that memory reclaim can
always make progress when it needs to force the log. The problem
with doing this is that a CIL push can take place while we are
determining if we need to allocate a new log vector buffer for
an item and hence the current log vector may go away without
warning. That means we canot rely on the existing log vector being
present when we finally grab the context lock and so we must have a
replacement buffer ready to go at all times.

To ensure this, introduce a "shadow log vector" buffer that is
always guaranteed to be present when we gain the CIL context lock
and format the item. This shadow buffer may or may not be used
during the formatting, but if the log item does not have an existing
log vector buffer or that buffer is too small for the new
modifications, we swap it for the new shadow buffer and format
the modifications into that new log vector buffer.

The result of this is that for any object we modify more than once
in a given CIL checkpoint, we double the memory required
to track dirty regions in the log. For single modifications then
we consume the shadow log vectorwe allocate on commit, and that gets
consumed by the checkpoint. However, if we make multiple
modifications, then the second transaction commit will allocate a
shadow log vector and hence we will end up with double the memory
usage as only one of the log vectors is consumed by the CIL
checkpoint. The remaining shadow vector will be freed when th elog
item is freed.

This can probably be optimised in future - access to the shadow log
vector is serialised by the object lock (as opposited to the active
log vector, which is controlled by the CIL context lock) and so we
can probably free shadow log vector from some objects when the log
item is marked clean on removal from the AIL.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Merge xfs_trans_reserve and xfs_trans_alloc into a single function call
that returns a transaction with all the required log and block reservations,
and which allows passing transaction flags directly to avoid the cumbersome
_xfs_trans_alloc interface.

While we're at it we also get rid of the transaction type argument that has
been superflous since we stopped supporting the non-CIL logging mode.  The
guts of it will be removed in another patch.

[dchinner: fixed transaction leak in error path in xfs_setattr_nonsize]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Just use the t_blk_res field directly instead of obsfucating the reference
by a macro.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Log recovery attempts to free extents with leftover EFIs in the AIL
after initial processing. If the extent free fails (e.g., due to
unrelated fs corruption), the transaction is cancelled, though it
might not be dirtied at the time. If this is the case, the EFD does
not abort and thus does not release the EFI. This can lead to hangs
as the EFI pins the AIL.

Update xlog_recover_process_efi() to log the EFD in the transaction
before xfs_free_extent() errors are handled to ensure the
transaction is dirty, aborts the EFD and releases the EFI on error.
Since this is a requirement for EFD processing (and consistent with
xfs_bmap_finish()), update the EFD logging helper to do the extent
free and unconditionally log the EFD. This encodes the required EFD
logging behavior into the helper and reduces the likelihood of
errors down the road.

[dchinner: re-add xfs_alloc.h to xfs_log_recover.c to fix build
 failure.]
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Some callers need to make error handling decisions based on whether
the current transaction successfully committed or not. Rename
xfs_trans_roll(), add a new parameter and provide a wrapper to
preserve existing callers.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Release of the EFI either occurs based on the reference count or the
extent count. The extent count used is either the count tracked in
the EFI or EFD, depending on the particular situation. In either
case, the count is initialized to the final value and thus always
matches the current efi_next_extent value once the EFI is completely
constructed.  For example, the EFI extent count is increased as the
extents are logged in xfs_bmap_finish() and the full free list is
always completely processed. Therefore, the count is guaranteed to
be complete once the EFI transaction is committed. The EFD uses the
efd_nextents counter to release the EFI. This counter is initialized
to the count of the EFI when the EFD is created. Thus the EFD, as
currently used, has no concept of partial EFI release based on
extent count.

Given that the EFI extent count is always released in whole, use of
the extent count for reference counting is unnecessary. Remove this
level of the API and release the EFI based on the core reference
count. The efi_next_extent counter remains because it is still used
to track the slot to log the next extent to free.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

The flags argument to xfs_trans_commit is not useful for most callers, as
a commit of a transaction without a permanent log reservation must pass
0 here, and all callers for a transaction with a permanent log reservation
except for xfs_trans_roll must pass XFS_TRANS_RELEASE_LOG_RES.  So remove
the flags argument from the public xfs_trans_commit interfaces, and
introduce low-level __xfs_trans_commit variant just for xfs_trans_roll
that regrants a log reservation instead of releasing it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

xfs_trans_cancel takes two flags arguments: XFS_TRANS_RELEASE_LOG_RES and
XFS_TRANS_ABORT.  Both of them are a direct product of the transaction
state, and can be deducted:

 - any dirty transaction needs XFS_TRANS_ABORT to be properly canceled,
   and XFS_TRANS_ABORT is a noop for a transaction that is not dirty.
 - any transaction with a permanent log reservation needs
   XFS_TRANS_RELEASE_LOG_RES to be properly canceled, and passing
   XFS_TRANS_RELEASE_LOG_RES for a transaction without a permanent
   log reservation is invalid.

So just remove the flags argument and do the right thing.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

We have three remaining callers of xfs_trans_dup:

 - xfs_itruncate_extents which open codes xfs_trans_roll
 - xfs_bmap_finish doesn't have an xfs_inode argument and thus leaves
   attaching them to it's callers, but otherwise is identical to
   xfs_trans_roll
 - xfs_dir_ialloc looks at the log reservations in the old xfs_trans
   structure instead of the log reservation parameters, but otherwise
   is identical to xfs_trans_roll.

By allowing a NULL xfs_inode argument to xfs_trans_roll we can switch
these three remaining users over to xfs_trans_roll and mark xfs_trans_dup
static.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Instead of setting up pointers to memory locations in iop_format which then
get copied into the CIL linear buffer after return move the copy into
the individual inode items.  This avoids the need to always have a memory
block in the exact same layout that gets written into the log around, and
allow the log items to be much more flexible in their in-memory layouts.

The only caveat is that we need to properly align the data for each
iovec so that don't have structures misaligned in subsequent iovecs.

Note that all log item format routines now need to be careful to modify
the copy of the item that was placed into the CIL after calls to
xlog_copy_iovec instead of the in-memory copy.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Currently the xfs_inode.h header has a dependency on the definition
of the BMAP btree records as the inode fork includes an array of
xfs_bmbt_rec_host_t objects in it's definition.

Move all the btree format definitions from xfs_btree.h,
xfs_bmap_btree.h, xfs_alloc_btree.h and xfs_ialloc_btree.h to
xfs_format.h to continue the process of centralising the on-disk
format definitions. With this done, the xfs inode definitions are no
longer dependent on btree header files.

The enables a massive culling of unnecessary includes, with close to
200 #include directives removed from the XFS kernel code base.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

xfs_trans.h has a dependency on xfs_log.h for a couple of
structures. Most code that does transactions doesn't need to know
anything about the log, but this dependency means that they have to
include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header
files and clean up the includes to be in dependency order.

In doing this, remove the direct include of xfs_trans_reserve.h from
xfs_trans.h so that we remove the dependency between xfs_trans.h and
xfs_mount.h. Hence the xfs_trans.h include can be moved to the
indicate the actual dependencies other header files have on it.

Note that these are kernel only header files, so this does not
translate to any userspace changes at all.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

We don't do callbacks at transaction commit time, no do we have any
infrastructure to set up or run such callbacks, so remove the
variables and typedefs for these operations. If we ever need to add
callbacks, we can reintroduce the variables at that time.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

In optimising the CIL operations, some of the IOP_* macros for
calling log item operations were removed. Remove the rest of them as
Christoph requested.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NGeoffrey Wehrman <gwehrman@sgi.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Now that we have the size of the log vector that has been allocated,
we can determine if we need to allocate a new log vector for
formatting and insertion. We only need to allocate a new vector if
it won't fit into the existing buffer.

However, we need to hold the CIL context lock while we do this so
that we can't race with a push draining the currently queued log
vectors. It is safe to do this as long as we do GFP_NOFS allocation
to avoid avoid memory allocation recursing into the filesystem.
Hence we can safely overwrite the existing log vector on the CIL if
it is large enough to hold all the dirty regions of the current
item.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Now that we have the size of the object before the formatting pass
is called, we can allocation the log vector and it's buffer in a
single allocation rather than two separate allocations.

Store the size of the allocated buffer in the log vector so that
we potentially avoid allocation for future modifications of the
object.

While touching this code, remove the IOP_FORMAT definition.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

To begin optimising the CIL commit process, we need to have IOP_SIZE
return both the number of vectors and the size of the data pointed
to by the vectors. This enables us to calculate the size ofthe
memory allocation needed before the formatting step and reduces the
number of memory allocations per item by one.

While there, kill the IOP_SIZE macro.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

With the new xfs_trans_res structure has been introduced, the log
reservation size, log count as well as log flags are pre-initialized
at mount time.  So it's time to refine xfs_trans_reserve() interface
to be more neat.

Also, introduce a new helper M_RES() to return a pointer to the
mp->m_resv structure to simplify the input.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The transaction reservation size calculations is used by both kernel
and userspace, but most of the transaction code in xfs_trans.c is
kernel specific. Split all the transaction reservation code out into
it's own files to make sharing with userspace simpler. This just
leaves kernel-only definitions in xfs_trans.h, so it doesn't need to
be shared with userspace anymore, either.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Little things like exported functions, __KERNEL__ protections, and
so on that ensure user and kernel shared headers are identical.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

There's a bunch of definitions in xfs_trans.h that define on-disk
formats - transaction headers that get written into the log, log
item type definitions, etc. Split out everything into a separate
file so that all which remains in xfs_trans.h are kernel only
definitions.

Also, remove the duplicate magic number definitions for
XFS_TRANS_MAGIC...
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Introduce the inode create log item type for logical inode create logging.
Instead of logging the changes in buffers, pass the range to be
initialised through the log by a new transaction type.  This reduces
the amount of log space required to record initialisation during
allocation from about 128 bytes per inode to a small fixed amount
per inode extent to be initialised.

This requires a new log item type to track it through the log
and the AIL. This is a relatively simple item - most callbacks are
noops as this item has the same life cycle as the transaction.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

If we have a buffer that we have modified but we do not wish to
physically log in a transaction (e.g. we've logged a logical
change), we still need to ensure that transactional integrity is
maintained. Hence we must not move the tail of the log past the
transaction that the buffer is associated with before the buffer is
written to disk.

This means these special buffers still need to be included in the
transaction and added to the AIL just like a normal buffer, but we
do not want the modifications to the buffer written into the
transaction. IOWs, what we want is an "ordered buffer" that
maintains the same transactional life cycle as a physically logged
buffer, just without the transcribing of the modifications to the
log.

Hence we need to flag the buffer as an "ordered buffer" to avoid
including it in vector size calculations or formatting during the
transaction. Once the transaction is committed, the buffer appears
for all intents to be the same as a physically logged buffer as it
transitions through the log and AIL.

Relogging will also work just fine for such an ordered buffer - the
logical transaction will be replayed before the subsequent
modifications that relog the buffer, so everything will be
reconstructed correctly by recovery.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Upstream commit 5b292ae3
	xfs: make use of xfs_calc_buf_res() in xfs_trans.c

Beginning from above commit, neither XFS_ALLOCFREE_LOG_RES() nor
XFS_DIROP_LOG_RES() is used by those routines for calculating
transaction space reservations, so it's safe to remove them now.

Also, with a slightly update for the relevant comments to reflect
the ideas of why those log count numbers should be.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Running a CONFIG_XFS_DEBUG kernel in production environments is not
the best idea as it introduces significant overhead, can change
the behaviour of algorithms (such as allocation) to improve test
coverage, and (most importantly) panic the machine on non-fatal
errors.

There are many cases where all we want to do is run a
kernel with more bounds checking enabled, such as is provided by the
ASSERT() statements throughout the code, but without all the
potential overhead and drawbacks.

This patch converts all the ASSERT statements to evaluate as
WARN_ON(1) statements and hence if they fail dump a warning and a
stack trace to the log. This has minimal overhead and does not
change any algorithms, and will allow us to find strange "out of
bounds" problems more easily on production machines.

There are a few places where assert statements contain debug only
code. These are converted to be debug-or-warn only code so that we
still get all the assert checks in the code.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The buffer type passed to log recvoery in the buffer log item
overruns the blf_flags field. I had assumed that flags field was a
32 bit value, and it turns out it is a unisgned short. Therefore
having 19 flags doesn't really work.

Convert the buffer type field to numeric value, and use the top 5
bits of the flags field for it. We currently have 17 types of
buffers, so using 5 bits gives us plenty of room for expansion in
future....
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Add buffer types to the buffer log items so that log recovery can
validate the buffers and calculate CRCs correctly after the buffers
are recovered.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Add support for larger btree blocks that contains a CRC32C checksum,
a filesystem uuid and block number for detecting filesystem
consistency and out of place writes.

[dchinner@redhat.com] Also include an owner field to allow reverse
mappings to be implemented for improved repairability and a LSN
field to so that log recovery can easily determine the last
modification that made it to disk for each buffer.

[dchinner@redhat.com] Add buffer log format flags to indicate the
type of buffer to recovery so that we don't have to do blind magic
number tests to determine what the buffer is.

[dchinner@redhat.com] Modified to fit into the verifier structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Currently, we calculate the attribute set transaction
log space reservation at runtime in two parts:

1) XFS_ATTRSET_LOG_RES() which is calcuated out at mount time.

2) ((ext * (mp)->m_sb.sb_sectsize) + \
    (ext * XFS_FSB_TO_B((mp), XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK))) + \
    (128 * (ext + (ext * XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK))))))
which is calculated out at runtime since it depend on the given extent length in blocks.

This patch renamed XFS_ATTRSET_LOG_RES(mp) to XFS_ATTRSETM_LOG_RES(mp) to indicate
that it is figured out at mount time.  Introduce XFS_ATTRSETRT_LOG_RES(mp) which would
be used to calculate out the unit of the log space reservation for one block.

In this way, the total runtime space for the given extent length can be figured out by:
XFS_ATTRSETM_LOG_RES(mp) + XFS_ATTRSETRT_LOG_RES(mp) * ext
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Introduce a new transaction space reservation XFS_SB_LOG_RES() for
those transactions that need to modify the superblock on disk.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Convert the calculation for end of quotaoff log space reservation
from runtime to mount time.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>