When we create a directory, we reserve a number of blocks for the maximum
possible expansion of of the directory due to various btree splits,
freespace allocation, etc. Unfortunately, each allocation is not reflected
in the total number of blocks still available to the transaction, so the
maximal reservation is used over and over again.

This leads to problems where an allocation group has only enough blocks
for *some* of the allocations required for the directory modification.
After the first N allocations, the remaining blocks in the allocation
group drops below the total reservation, and subsequent allocations fail
because the allocator will not allow the allocation to proceed if the AG
does not have the enough blocks available for the entire allocation total.

This results in an ENOSPC occurring after an allocation has already
occurred. This results in aborting the directory operation (leaving the
directory in an inconsistent state) and cancelling a dirty transaction,
which results in a filesystem shutdown.

Avoid the problem by reflecting the number of blocks allocated in any
directory expansion in the total number of blocks available to the
modification in progress. This prevents a directory modification from
being aborted part way through with an ENOSPC.

SGI-PV: 988144

SGI-Modid: xfs-linux-melb:xfs-kern:32340a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

If the last block of the AG has inodes in it and the AG is an exactly
power-of-2 size then the last inode in the AG points to the last block in
the AG. If we try to find the next inode in the AG by adding one to the
inode number, we increment the inode number past the size of the AG. The
result is that the macro XFS_INO_TO_AGINO() will strip the AG portion of
the inode number and return an inode number of zero.

That is, instead of terminating the lookup loop because we hit the inode
number went outside the valid range for the AG, the search index returns
to zero and we start traversing the radix tree from the start again. This
results in an endless loop in xfs_sync_inodes_ag().

Fix it be detecting if the new search index decreases as a result of
incrementing the current inode number. That indicate an overflow and hence
that we have finished processing the AG so we can terminate the loop.

SGI-PV: 988142

SGI-Modid: xfs-linux-melb:xfs-kern:32335a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Now that the deleted inodes list is unused, kill it. This also removes the
i_reclaim list head from the xfs_inode, shrinking it by two pointers.

SGI-PV: 988142

SGI-Modid: xfs-linux-melb:xfs-kern:32334a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Use the reclaim tag to walk the radix tree and find the inodes under
reclaim. This was the only user of the deleted inode list.

SGI-PV: 988142

SGI-Modid: xfs-linux-melb:xfs-kern:32333a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Prepare for removing the deleted inode list by marking inodes for reclaim
in the inode radix trees so that we can use the radix trees to find
reclaimable inodes.

SGI-PV: 988142

SGI-Modid: xfs-linux-melb:xfs-kern:32331a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

The function names xfs_finish_reclaim and xfs_finish_reclaim_all are not
very descriptive of what they are reclaiming. Rename to
xfs_reclaim_inode[s] to match the xfs_sync_inodes() function.

SGI-PV: 988142

SGI-Modid: xfs-linux-melb:xfs-kern:32330a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Background inode reclaim is run by the xfssyncd. Move the reclaim worker
functions to be close to the sync code as the are very similar in
structure and are both run from the same background thread.

SGI-PV: 988142

SGI-Modid: xfs-linux-melb:xfs-kern:32329a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

SGI-PV: 988141

SGI-Modid: xfs-linux-melb:xfs-kern:32325a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

With the combined linux and XFS inode, we need to ensure that the combined
structure is not freed before the generic code is finished with the inode.
As it turns out, there is a case where the XFS inode is freed before the
linux inode - when xfs_reclaim() is called from ->clear_inode() on a clean
inode, the xfs inode is freed during that call. The generic code
references the inode after the ->clear_inode() call, so this is a use
after free situation.

Fix the problem by moving the xfs_reclaim() call to ->destroy_inode()
instead of in ->clear_inode(). This ensures the combined inode structure
is not freed until after the generic code has finished with it.

SGI-PV: 988141

SGI-Modid: xfs-linux-melb:xfs-kern:32324a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

To avoid issues with different lifecycles of XFS and Linux inodes, embedd
the linux inode inside the XFS inode. This means that the linux inode has
the same lifecycle as the XFS inode, even when it has been released by the
OS. XFS inodes don't live much longer than this (a short stint in reclaim
at most), so there isn't significant memory usage penalties here.

Version 3 o kill xfs_icount()

Version 2 o remove unused commented out code from xfs_iget(). o kill
useless cast in VFS_I()

SGI-PV: 988141

SGI-Modid: xfs-linux-melb:xfs-kern:32323a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

To allow XFS to combine the XFS and linux inodes into a single
structure, we need to drive inode lookup from the XFS inode cache,
not the generic inode cache. This means that we need initialise a
struct inode from a context outside alloc_inode() as it is no longer
used by XFS.

After inode allocation and initialisation, we need to add the inode
to the superblock list, the in-use list, hash it and do some
accounting. This all needs to be done with the inode_lock held and
there are already several places in fs/inode.c that do this list
manipulation.  Factor out the common code, add a locking wrapper and
export the function so ti can be called from XFS.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

To allow XFS to combine the XFS and linux inodes into a single
structure, we need to drive inode lookup from the XFS inode cache,
not the generic inode cache. This means that we need initialise a
struct inode from a context outside alloc_inode() as it is no longer
used by XFS.

Factor and export the struct inode initialisation code from
alloc_inode() to inode_init_always() as a counterpart to
inode_init_once().  i.e. we have to call this init function for each
inode instantiation (always), as opposed inode_init_once() which is
only called on slab object instantiation (once).
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Once the Linux inode and the XFS inode are combined, we cannot rely on
just check if the linux inode exists as a method of determining if it is
valid or not. Hence we should always call xfs_mark_inode_dirty_sync()
instead as it does the correct checks to determine if the liinux inode is
in a valid state or not.

SGI-PV: 988141

SGI-Modid: xfs-linux-melb:xfs-kern:32318a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

There are really two cases in xfs_iget_core(). The first is the cache hit
case, the second is the miss case. They share very little code, and hence
can easily be factored out into separate functions. This makes the code
much easier to understand and subsequently modify.

SGI-PV: 988141

SGI-Modid: xfs-linux-melb:xfs-kern:32317a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

We can only read inode->i_count if the inode is actually there and not a
NULL pointer. This was introduced in one of the recent sync patches.

SGI-PV: 988255

SGI-Modid: xfs-linux-melb:xfs-kern:32315a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

With all the other filesystem sync code it in xfs_sync.c including the
data quiesce code, it makes sense to move the remaining quiesce code to
the same place.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32312a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

There are no more callers to xfs_sync() now, so remove the function
altogther.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32311a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

SYNC_CLOSE is only ever used and checked in conjunction with SYNC_WAIT,
and this only done in one spot. The only thing this does is make
XFS_bflush() calls to the data buftargs.

This will happen very shortly afterwards the xfs_sync() call anyway in the
unmount path via the xfs_close_devices(), so this code is redundant and
can be removed. That only user of SYNC_CLOSE is now gone, so kill the flag
completely.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32310a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Continue to de-multiplex xfs_sync be replacing all SYNC_DELWRI callers
with direct calls functions that do the work. Isolate the data quiesce
case to a function in xfs_sync.c. Isolate the FSDATA case with explicit
calls to xfs_sync_fsdata().

Version 2: o Push delwri related log forces into xfs_sync_inodes().

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32309a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Continue to de-multiplex xfs_sync be replacing all SYNC_ATTR callers with
direct calls xfs_sync_inodes(). Add an assert into xfs_sync() to ensure we
caught all the SYNC_ATTR callers.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32308a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Start de-multiplexing xfs_sync() by making xfs_sync_worker() call the
specific sync functions it needs. This is only a small, unique subset of
the entire xfs_sync() code so is easier to follow.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32307a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Now that the only caller is xfs_sync(), merge the two together as it makes
no sense to keep them separate.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32306a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Kill the unused arg in xfs_syncsub() and xfs_sync_inodes(). For callers of
xfs_syncsub() that only want to flush inodes, replace xfs_syncsub() with
direct calls to xfs_sync_inodes() as that is all that is being done with
the specific flags being passed in.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32305a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

With the sync code relocated to the linux-2.6 directory we can use struct
inodes directly. If we do the same thing for the quota release code, we
can remove vn_grab altogether. While here, convert the VN_BAD() checks to
is_bad_inode() so we can remove vnodes entirely from this code.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32304a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Split out two helpers from xfs_syncsub for the dummy log commit and the
superblock writeout.

SGI-PV: 988140

SGI-Modid: xfs-linux-melb:xfs-kern:32303a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Move the XFS_BMAP_SANITY_CHECK macro out of line and make it a properly
typed function. Also pass the xfs_buf for the btree block instead of just
the btree block header, as we will need some additional information for it
to implement CRC checking of btree blocks.

SGI-PV: 988146

SGI-Modid: xfs-linux-melb:xfs-kern:32301a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

structures.

Always use the generic xfs_btree_block type instead of the short / long
structures. Add XFS_BTREE_SBLOCK_LEN / XFS_BTREE_LBLOCK_LEN defines for
the length of a short / long form block. The rationale for this is that we
will grow more btree block header variants to support CRCs and other RAS
information, and always accessing them through the same datatype with
unions for the short / long form pointers makes implementing this much
easier.

SGI-PV: 988146

SGI-Modid: xfs-linux-melb:xfs-kern:32300a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Replace the generic record / key / ptr addressing macros that use cpp
token pasting with simpler macros that do the job for just one given btree
type. The new macros lose the cur argument and thus can be used outside
the core btree code, but also gain an xfs_mount * argument to allow for
checking the CRC flag in the near future. Note that many of these macros
aren't actually used in the kernel code, but only in userspace (mostly in
xfs_repair).

SGI-PV: 988146

SGI-Modid: xfs-linux-melb:xfs-kern:32295a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Now we've removed all users of the mount inode list, we can kill it. This
reduces the size of the xfs_inode by 2 pointers.

SGI-PV: 988139

SGI-Modid: xfs-linux-melb:xfs-kern:32293a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Clean up the way the maximum and minimum records for the btree blocks are
calculated. For the alloc and inobt btrees all the values are
pre-calculated in xfs_mount_common, and we switch the current loop around
the ugly generic macros that use cpp token pasting to generate type names
to two small helpers in normal C code. For the bmbt and bmdr trees these
helpers also exist, but can be called during runtime, too. Here we also
kill various macros dealing with them and inline the logic into the
get_minrecs / get_maxrecs / get_dmaxrecs methods in xfs_bmap_btree.c.

Note that all these new helpers take an xfs_mount * argument which will be
needed to determine the size of a btree block once we add support for
extended btree blocks with CRCs and other RAS information.

SGI-PV: 988146

SGI-Modid: xfs-linux-melb:xfs-kern:32292a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Make releasing all inode dquots traverse the per-ag inode radix trees
rather than the mount inode list. This removes another user of the mount
inode list.

Version 3 o fix comment relating to avoiding trying to release the

quota inodes and those in reclaim.

Version 2 o add comment explaining use of gang lookups for a single inode
o use IRELE, not VN_RELE o move check for ag initialisation to caller.

SGI-PV: 988139

SGI-Modid: xfs-linux-melb:xfs-kern:32291a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Update xfs_sync_inodes to walk the inode radix tree cache to find dirty
inodes. This removes a huge bunch of nasty, messy code for traversing the
mount inode list safely and removes another user of the mount inode list.

Version 3 o rediff against new linux-2.6/xfs_sync.c code

Version 2 o add comment explaining use of gang lookups for a single inode
o use IRELE, not VN_RELE o move check for ag initialisation to caller.

SGI-PV: 988139

SGI-Modid: xfs-linux-melb:xfs-kern:32290a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Normally dquots are written back via delayed write mechanisms. They are
flushed to their backing buffer by xfssyncd, which is then pushed out by
either AIL or xfsbufd flushing. The flush from the xfssyncd is supposed to
be non-blocking, but xfs_qm_dqflush() always waits for pinned duots, which
means that it will block for the length of time it takes to do a
synchronous log force. This causes unnecessary extra log I/O to be issued
whenever we try to flush a busy dquot.

Avoid the log forces and blocking xfssyncd by making xfs_qm_dqflush() pay
attention to what type of sync it is doing when it sees a pinned dquot and
not waiting when doing non-blocking flushes.

SGI-PV: 988147

SGI-Modid: xfs-linux-melb:xfs-kern:32287a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NPeter Leckie <pleckie@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_iflush_all() walks the m_inodes list to find inodes that need
reclaiming. We already have such a list - the m_del_inodes list. Replace
xfs_iflush_all() with a call to xfs_finish_reclaim_all() and clean up
xfs_finish_reclaim_all() to handle the different flush modes now needed.

Originally based on a patch from Christoph Hellwig.

Version 3 o rediff against new linux-2.6/xfs_sync.c code

Version 2 o revert xfs_syncsub() inode reclaim behaviour back to original

code o xfs_quiesce_fs() should use XFS_IFLUSH_DELWRI_ELSE_ASYNC, not

XFS_IFLUSH_ASYNC, to prevent change of behaviour.

SGI-PV: 988139

SGI-Modid: xfs-linux-melb:xfs-kern:32284a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Move all the xfssyncd code to the new xfs_sync.c file. This places it
closer to the actual code that it interacts with, rather than just being
associated with high level VFS code.

SGI-PV: 988139

SGI-Modid: xfs-linux-melb:xfs-kern:32283a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

The sync code in XFS is spread around several files. While it used to make
sense to have such a distribution, the code is about to be cleaned up and
so centralising it in one spot as the first step makes sense.

SGI-PV: 988139

SGI-Modid: xfs-linux-melb:xfs-kern:32282a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

SGI-PV: 987246

SGI-Modid: xfs-linux-melb:xfs-kern:32233a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 987683

SGI-Modid: xfs-linux-melb:xfs-kern:32232a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 986558

SGI-Modid: xfs-linux-melb:xfs-kern:32231a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32224a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>