Dave Chinner [Wed, 28 Nov 2012 02:01:00 +0000 (13:01 +1100)]
xfs: fix direct IO nested transaction deadlock.
The direct IO path can do a nested transaction reservation when
writing past the EOF. The first transaction is the append
transaction for setting the filesize at IO completion, but we can
also need a transaction for allocation of blocks. If the log is low
on space due to reservations and small log, the append transaction
can be granted after wating for space as the only active transaction
in the system. This then attempts a reservation for an allocation,
which there isn't space in the log for, and the reservation sleeps.
The result is that there is nothing left in the system to wake up
all the processes waiting for log space to come free.
The stack trace that shows this deadlock is relatively innocuous:
This was discovered on a filesystem with a log of only 10MB, and a
log stripe unit of 256k whih increased the base reservations by
512k. Hence a allocation transaction requires 1.2MB of log space to
be available instead of only 260k, and so greatly increased the
chance that there wouldn't be enough log space available for the
nested transaction to succeed. The key to reproducing it is this
mkfs command:
The test case was a 1000 fsstress processes running with random
freeze and unfreezes every few seconds. Thanks to Eryu Guan
(eguan@redhat.com) for writing the test that found this on a system
with a somewhat unique default configuration....
cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andrew Dahl <adahl@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Thu, 29 Nov 2012 04:26:33 +0000 (15:26 +1100)]
xfs: byte range granularity for XFS_IOC_ZERO_RANGE
XFS_IOC_ZERO_RANGE simply does not work properly for non page cache
aligned ranges. Neither test 242 or 290 exercise this correctly, so
the behaviour is completely busted even though the tests pass.
Fix it to support full byte range granularity as was originally
intended for this ioctl.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 23 Nov 2012 03:24:23 +0000 (14:24 +1100)]
xfs: inode allocation should use unmapped buffers.
Inode buffers do not need to be mapped as inodes are read or written
directly from/to the pages underlying the buffer. This fixes a
regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the
default behaviour").
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Implement CRCs for the log buffers. We re-use a field in
struct xlog_rec_header that was used for a weak checksum of the
log buffer payload in debug builds before.
The new checksumming uses the crc32c checksum we will use elsewhere
in XFS, and also protects the record header and addition cycle data.
Due to this there are some interesting changes in xlog_sync, as we
need to do the cycle wrapping for the split buffer case much earlier,
as we would touch the buffer after generating the checksum otherwise.
The CRC calculation is always enabled, even for non-CRC filesystems,
as adding this CRC does not change the log format. On non-CRC
filesystems, only issue an alert if a CRC mismatch is found and
allow recovery to continue - this will act as an indicator that
log recovery problems are a result of log corruption. On CRC enabled
filesystems, however, log recovery will fail.
Note that existing debug kernels will write a simple checksum value
to the log, so the first time this is run on a filesystem taht was
last used on a debug kernel it will through CRC mismatch warning
errors. These can be ignored.
Initially based on a patch from Dave Chinner, then modified
significantly by Christoph Hellwig. Modified again by Dave Chinner
to get to this version.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
- add a mount feature bit for CRC enabled filesystems
- add some helpers for generating and verifying the CRCs
- add a copy_uuid helper
The checksumming helpers are loosely based on similar ones in sctp,
all other bits come from Dave Chinner.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Wed, 14 Nov 2012 06:54:40 +0000 (17:54 +1100)]
xfs: convert buffer verifiers to an ops structure.
To separate the verifiers from iodone functions and associate read
and write verifiers at the same time, introduce a buffer verifier
operations structure to the xfs_buf.
This avoids the need for assigning the write verifier, clearing the
iodone function and re-running ioend processing in the read
verifier, and gets rid of the nasty "b_pre_io" name for the write
verifier function pointer. If we ever need to, it will also be
easier to add further content specific callbacks to a buffer with an
ops structure in place.
We also avoid needing to export verifier functions, instead we
can simply export the ops structures for those that are needed
outside the function they are defined in.
This patch also fixes a directory block readahead verifier issue
it exposed.
This patch also adds ops callbacks to the inode/alloc btree blocks
initialised by growfs. These will need more work before they will
work with CRCs.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Wed, 14 Nov 2012 06:53:49 +0000 (17:53 +1100)]
xfs: connect up write verifiers to new buffers
Metadata buffers that are read from disk have write verifiers
already attached to them, but newly allocated buffers do not. Add
appropriate write verifiers to all new metadata buffers.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
These verifiers are essentially the same code as the read verifiers,
but do not require ioend processing. Hence factor the read verifier
functions and add a new write verifier wrapper that is used as the
callback.
This is done as one large patch for all verifiers rather than one
patch per verifier as the change is largely mechanical. This
includes hooking up the write verifier via the read verifier
function.
Hooking up the write verifier for buffers obtained via
xfs_trans_get_buf() will be done in a separate patch as that touches
code in many different places rather than just the verifier
functions.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:19 +0000 (22:54 +1100)]
xfs: add buffer pre-write callback
Add a callback to the buffer write path to enable verification of
the buffer and CRC calculation prior to issuing the write to the
underlying storage.
If the callback function detects some kind of failure or error
condition, it must mark the buffer with an error so that the caller
can take appropriate action. In the case of xfs_buf_ioapply(), a
corrupt metadta buffer willt rigger a shutdown of the filesystem,
because something is clearly wrong and we can't allow corrupt
metadata to be written to disk.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:16 +0000 (22:54 +1100)]
xfs: factor and verify attr leaf reads
Some reads are not converted yet because it isn't obvious ahead of
time what the format of the block is going to be. Need to determine
how to tell if the first block in the tree is a node or leaf format
block. That will be done in later patches.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:12 +0000 (22:54 +1100)]
xfs: verify dir2 block format buffers
Add a dir2 block format read verifier. To fully verify every block
when read, call xfs_dir2_data_check() on them. Change
xfs_dir2_data_check() to do runtime checking, convert ASSERT()
checks to XFS_WANT_CORRUPTED_RETURN(), which will trigger an ASSERT
failure on debug kernels, but on production kernels will dump an
error to dmesg and return EFSCORRUPTED to the caller.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:11 +0000 (22:54 +1100)]
xfs: factor dir2 block read operations
In preparation for verifying dir2 block format buffers, factor
the read operations out of the block operations (lookup, addname,
getdents) and some of the additional logic to make it easier to
understand an dmodify the code.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:10 +0000 (22:54 +1100)]
xfs: add verifier callback to directory read code
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Wed, 14 Nov 2012 06:50:13 +0000 (17:50 +1100)]
xfs: verify dquot blocks as they are read from disk
Add a dquot buffer verify callback function and pass it into the
buffer read functions. This checks all the dquots in a buffer, but
cannot completely verify the dquot ids are correct. Also, errors
cannot be repaired, so an additional function is added to repair bad
dquots in the buffer if such an error is detected in a context where
repair is allowed.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:08 +0000 (22:54 +1100)]
xfs: verify btree blocks as they are read from disk
Add an btree block verify callback function and pass it into the
buffer read functions. Because each different btree block type
requires different verification, add a function to the ops structure
that is called from the generic code.
Also, propagate the verification callback functions through the
readahead functions, and into the external bmap and bulkstat inode
readahead code that uses the generic btree buffer read functions.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:07 +0000 (22:54 +1100)]
xfs: verify inode buffers as they are read from disk
Add an inode buffer verify callback function and pass it into the
buffer read functions. Inodes are special in that the verbose checks
will be done when reading the inode, but we still need to sanity
check the buffer when that is first read. Always verify the magic
numbers in all inodes in the buffer, rather than jus ton debug
kernels.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:06 +0000 (22:54 +1100)]
xfs: verify AGFL blocks as they are read from disk
Add an AGFL block verify callback function and pass it into the
buffer read functions.
While this commit adds verification code to the AGFL, it cannot be
used reliably until the CRC format change comes along as mkfs does
not initialise the full AGFL. Hence it can be full of garbage at the
first mount and will fail verification right now. CRC enabled
filesystems won't have this problem, so leave the code that has
already been written ifdef'd out until the proper time.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:05 +0000 (22:54 +1100)]
xfs: verify AGI blocks as they are read from disk
Add an AGI block verify callback function and pass it into the
buffer read functions. Remove the now redundant verification code
that is currently in use.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Wed, 14 Nov 2012 06:44:56 +0000 (17:44 +1100)]
xfs: verify AGF blocks as they are read from disk
Add an AGF block verify callback function and pass it into the
buffer read functions. This replaces the existing verification that
is done after the read completes.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:03 +0000 (22:54 +1100)]
xfs: verify superblocks as they are read from disk
Add a superblock verify callback function and pass it into the
buffer read functions. Remove the now redundant verification code
that is currently in use.
Adding verification shows that secondary superblocks never have
their "sb_inprogress" flag cleared by mkfs.xfs, so when validating
the secondary superblocks during a grow operation we have to avoid
checking this field. Even if we fix mkfs, we will still have to
ignore this field for verification purposes unless a version of mkfs
that does not have this bug was used.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:02 +0000 (22:54 +1100)]
xfs: uncached buffer reads need to return an error
With verification being done as an IO completion callback, different
errors can be returned from a read. Uncached reads only return a
buffer or NULL on failure, which means the verification error cannot
be returned to the caller.
Split the error handling for these reads into two - a failure to get
a buffer will still return NULL, but a read error will return a
referenced buffer with b_error set rather than NULL. The caller is
responsible for checking the error state of the buffer returned.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:01 +0000 (22:54 +1100)]
xfs: make buffer read verication an IO completion function
Add a verifier function callback capability to the buffer read
interfaces. This will be used by the callers to supply a function
that verifies the contents of the buffer when it is read from disk.
This patch does not provide callback functions, but simply modifies
the interfaces to allow them to be called.
The reason for adding this to the read interfaces is that it is very
difficult to tell fom the outside is a buffer was just read from
disk or whether we just pulled it out of cache. Supplying a callbck
allows the buffer cache to use it's internal knowledge of the buffer
to execute it only when the buffer is read from disk.
It is intended that the verifier functions will mark the buffer with
an EFSCORRUPTED error when verification fails. This allows the
reading context to distinguish a verification error from an IO
error, and potentially take further actions on the buffer (e.g.
attempt repair) based on the error reported.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:53:57 +0000 (22:53 +1100)]
xfs: remove xfs_flushinval_pages
It's just a simple wrapper around VFS functionality, and is actually
bugging in that it doesn't remove mappings before invalidating the
page cache. Remove it and replace it with the correct VFS
functionality.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Andrew Dahl <adahl@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:53:56 +0000 (22:53 +1100)]
xfs: remove xfs_flush_pages
It is a complex wrapper around VFS functions, but there are VFS
functions that provide exactly the same functionality. Call the VFS
functions directly and remove the unnecessary indirection and
complexity.
We don't need to care about clearing the XFS_ITRUNCATED flag, as
that is done during .writepages. Hence is cleared by the VFS
writeback path if there is anything to write back during the flush.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Andrew Dahl <adahl@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:53:55 +0000 (22:53 +1100)]
xfs: remove xfs_wait_on_pages()
It's just a simple wrapper around a VFS function that is only called
by another function in xfs_fs_subr.c. Remove it and call the VFS
function directly.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Andrew Dahl <adahl@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Wed, 14 Nov 2012 06:42:47 +0000 (17:42 +1100)]
xfs: remove xfs_tosspages
It's a buggy, unnecessary wrapper that is duplicating
truncate_pagecache_range().
When replacing the call in xfs_change_file_space(), also ensure that
the length being allocated/freed is always positive before making
any changes. These checks are done in the lower extent manipulation
functions, too, but we need to do them before any page cache
operations.
Reported-by: Andrew Dahl <adahl@sgi.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-By: Andrew Dahl <adahl@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:54:00 +0000 (22:54 +1100)]
xfs: make growfs initialise the AGFL header
For verification purposes, AGFLs need to be initialised to a known
set of values. For upcoming CRC changes, they are also headers that
need to be initialised. Currently, growfs does neither for the AGFLs
- it ignores them completely. Add initialisation of the AGFL to be
full of invalid block numbers (NULLAGBLOCK) to put the
infrastructure in place needed for CRC support.
Includes a comment clarification from Jeff Liu.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:53:59 +0000 (22:53 +1100)]
xfs: growfs: use uncached buffers for new headers
When writing the new AG headers to disk, we can't attach write
verifiers because they have a dependency on the struct xfs-perag
being attached to the buffer to be fully initialised and growfs
can't fully initialise them until later in the process.
The simplest way to avoid this problem is to use uncached buffers
for writing the new headers. These buffers don't have the xfs-perag
attached to them, so it's simple to detect in the write verifier and
be able to skip the checks that need the xfs-perag.
This enables us to attach the appropriate buffer ops to the buffer
and hence calculate CRCs on the way to disk. IT also means that the
buffer is torn down immediately, and so the first access to the AG
headers will re-read the header from disk and perform full
verification of the buffer. This way we also can catch corruptions
due to problems that went undetected in growfs.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Tue, 13 Nov 2012 22:40:27 +0000 (16:40 -0600)]
xfs: use btree block initialisation functions in growfs
Factor xfs_btree_init_block() to be independent of the btree cursor,
and use the function to initialise btree blocks in the growfs code.
This makes adding support for different format btree blocks simple.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:53:53 +0000 (22:53 +1100)]
xfs: add more attribute tree trace points.
Added when debugging recent attribute tree problems to more finely
trace code execution through the maze of twisty passages that makes
up the attr code.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:09:46 +0000 (22:09 +1100)]
xfs: drop buffer io reference when a bad bio is built
Error handling in xfs_buf_ioapply_map() does not handle IO reference
counts correctly. We increment the b_io_remaining count before
building the bio, but then fail to decrement it in the failure case.
This leads to the buffer never running IO completion and releasing
the reference that the IO holds, so at unmount we can leak the
buffer. This leak is captured by this assert failure during unmount:
This is not a new bug - the b_io_remaining accounting has had this
problem for a long, long time - it's just very hard to get a
zero length bio being built by this code...
Further, the buffer IO error can be overwritten on a multi-segment
buffer by subsequent bio completions for partial sections of the
buffer. Hence we should only set the buffer error status if the
buffer is not already carrying an error status. This ensures that a
partial IO error on a multi-segment buffer will not be lost. This
part of the problem is a regression, however.
cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:09:45 +0000 (22:09 +1100)]
xfs: fix broken error handling in xfs_vm_writepage
When we shut down the filesystem, it might first be detected in
writeback when we are allocating a inode size transaction. This
happens after we have moved all the pages into the writeback state
and unlocked them. Unfortunately, if we fail to set up the
transaction we then abort writeback and try to invalidate the
current page. This then triggers are BUG() in block_invalidatepage()
because we are trying to invalidate an unlocked page.
Fixing this is a bit of a chicken and egg problem - we can't
allocate the transaction until we've clustered all the pages into
the IO and we know the size of it (i.e. whether the last block of
the IO is beyond the current EOF or not). However, we don't want to
hold pages locked for long periods of time, especially while we lock
other pages to cluster them into the write.
To fix this, we need to make a clear delineation in writeback where
errors can only be handled by IO completion processing. That is,
once we have marked a page for writeback and unlocked it, we have to
report errors via IO completion because we've already started the
IO. We may not have submitted any IO, but we've changed the page
state to indicate that it is under IO so we must now use the IO
completion path to report errors.
To do this, add an error field to xfs_submit_ioend() to pass it the
error that occurred during the building on the ioend chain. When
this is non-zero, mark each ioend with the error and call
xfs_finish_ioend() directly rather than building bios. This will
immediately push the ioends through completion processing with the
error that has occurred.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 12 Nov 2012 11:09:44 +0000 (22:09 +1100)]
xfs: fix attr tree double split corruption
In certain circumstances, a double split of an attribute tree is
needed to insert or replace an attribute. In rare situations, this
can go wrong, leaving the attribute tree corrupted. In this case,
the attr being replaced is the last attr in a leaf node, and the
replacement is larger so doesn't fit in the same leaf node.
When we have the initial condition of a node format attribute
btree with two leaves at index 1 and 2. Call them L1 and L2. The
leaf L1 is completely full, there is not a single byte of free space
in it. L2 is mostly empty. The attribute being replaced - call it X
- is the last attribute in L1.
The way an attribute replace is executed is that the replacement
attribute - call it Y - is first inserted into the tree, but has an
INCOMPLETE flag set on it so that list traversals ignore it. Once
this transaction is committed, a second transaction it run to
atomically mark Y as COMPLETE and X as INCOMPLETE, so that a
traversal will now find Y and skip X. Once that transaction is
committed, attribute X is then removed.
So now we go to replace X, and see that L1:fsp = 0 - it is full so
we can't insert Y in the same leaf. So we record the the location of
attribute X so we can track it for later use, then we split L1 into
L1 and L3 and reblance across the two leafs. We end with:
And we track that the original attribute is now at L3:0.
We then try to insert Y into L1 again, and find that there isn't
enough room because the new attribute is larger than the old one.
Hence we have to split again to make room for Y. We end up with
this:
And now we have the new (incomplete) attribute @ L4:0, and the
original attribute at L3:0. At this point, the first transaction is
committed, and we move to the flipping of the flags.
This is where we are supposed to end up with this:
But that doesn't happen properly - the attribute tracking indexes
are not pointing to the right locations. What we end up with is both
the old attribute to be removed pointing at L4:0 and the new
attribute at L4:1. On a debug kernel, this assert fails like so:
because the new attribute location does not exist. On a production
kernel, this goes unnoticed and the code proceeds ahead merrily and
removes L4 because it thinks that is the block that is no longer
needed. This leaves the hash index node pointing to entries
L1, L4 and L2, but only blocks L1, L3 and L2 to exist. Further, the
leaf level sibling list is L1 <-> L4 <-> L2, but L4 is now free
space, and so everything is busted. This corruption is caused by the
removal of the old attribute triggering a join - it joins everything
correctly but then frees the wrong block.
xfs_repair will report something like:
bad sibling back pointer for block 4 in attribute fork for inode 131
problem with attribute contents in inode 131
would clear attr fork
bad nblocks 8 for inode 131, would reset to 3
bad anextents 4 for inode 131, would reset to 0
The problem lies in the assignment of the old/new blocks for
tracking purposes when the double leaf split occurs. The first split
tries to place the new attribute inside the current leaf (i.e.
"inleaf == true") and moves the old attribute (X) to the new block.
This sets up the old block/index to L1:X, and newly allocated
block to L3:0. It then moves attr X to the new block and tries to
insert attr Y at the old index. That fails, so it splits again.
With the second split, the rebalance ends up placing the new attr in
the second new block - L4:0 - and this is where the code goes wrong.
What is does is it sets both the new and old block index to the
second new block. Hence it inserts attr Y at the right place (L4:0)
but overwrites the current location of the attr to replace that is
held in the new block index (currently L3:0). It over writes it with
L4:1 - the index we later assert fail on.
Hopefully this table will show this in a foramt that is a bit easier
to understand:
Split old attr index new attr index
vanilla patched vanilla patched
before 1st L1:26 L1:26 N/A N/A
after 1st L3:0 L3:0 L1:26 L1:26
after 2nd L4:0 L3:0 L4:1 L4:0
^^^^ ^^^^
wrong wrong
The fix is surprisingly simple, for all this analysis - just stop
the rebalance on the out-of leaf case from overwriting the new attr
index - it's already correct for the double split case.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:47 +0000 (09:50 -0500)]
xfs: add background scanning to clear eofblocks inodes
Create a new mount workqueue and delayed_work to enable background
scanning and freeing of eofblocks inodes. The scanner kicks in once
speculative preallocation occurs and stops requeueing itself when
no eofblocks inodes exist.
The scan interval is based on the new
'speculative_prealloc_lifetime' tunable (default to 5m). The
background scanner performs unfiltered, best effort scans (which
skips inodes under lock contention or with a dirty cache mapping).
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Wed, 7 Nov 2012 17:21:14 +0000 (12:21 -0500)]
xfs: add minimum file size filtering to eofblocks scan
Support minimum file size filtering in the eofblocks scan. The
caller must set the XFS_EOF_FLAGS_MINFILESIZE flags bit and minimum
file size value in bytes.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:45 +0000 (09:50 -0500)]
xfs: support multiple inode id filtering in eofblocks scan
Enhance the eofblocks scan code to filter based on multiply specified
inode id values. When multiple inode id values are specified, only
inodes that match all id values are selected.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Wed, 7 Nov 2012 17:21:13 +0000 (12:21 -0500)]
xfs: add inode id filtering to eofblocks scan
Support inode ID filtering in the eofblocks scan. The caller must
set the associated XFS_EOF_FLAGS_*ID bit and ID field.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Wed, 7 Nov 2012 17:21:12 +0000 (12:21 -0500)]
xfs: add XFS_IOC_FREE_EOFBLOCKS ioctl
The XFS_IOC_FREE_EOFBLOCKS ioctl allows users to invoke an EOFBLOCKS
scan. The xfs_eofblocks structure is defined to support the command
parameters (scan mode).
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:42 +0000 (09:50 -0500)]
xfs: create function to scan and clear EOFBLOCKS inodes
xfs_inodes_free_eofblocks() implements scanning functionality for
EOFBLOCKS inodes. It uses the AG iterator to walk the tagged inodes
and free post-EOF blocks via the xfs_inode_free_eofblocks() execute
function. The scan can be invoked in best-effort mode or wait
(force) mode.
A best-effort scan (default) handles all inodes that do not have a
dirty cache and we successfully acquire the io lock via trylock. In
wait mode, we continue to cycle through an AG until all inodes are
handled.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:41 +0000 (09:50 -0500)]
xfs: make xfs_free_eofblocks() non-static, return EAGAIN on trylock failure
Turn xfs_free_eofblocks() into a non-static function, return EAGAIN to
indicate trylock failure and make sure this error is not propagated in
xfs_release().
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:40 +0000 (09:50 -0500)]
xfs: create helper to check whether to free eofblocks on inode
This check is used in multiple places to determine whether we
should check for (and potentially free) post EOF blocks on an
inode. Add a helper to consolidate the check.
Note that when we remove an inode from the cache (xfs_inactive()),
we are required to trim post-EOF blocks even if the inode is marked
preallocated or append-only to maintain correct space accounting.
The 'force' parameter to xfs_can_free_eofblocks() specifies whether
we should ignore the prealloc/append-only status of the inode.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:39 +0000 (09:50 -0500)]
xfs: support a tag-based inode_ag_iterator
Genericize xfs_inode_ag_walk() to support an optional radix tree tag
and args argument for the execute function. Create a new wrapper
called xfs_inode_ag_iterator_tag() that performs a tag based walk
of perag's and inodes.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Brian Foster [Tue, 6 Nov 2012 14:50:38 +0000 (09:50 -0500)]
xfs: add EOFBLOCKS inode tagging/untagging
Add the XFS_ICI_EOFBLOCKS_TAG inode tag to identify inodes with
speculatively preallocated blocks beyond EOF. An inode is tagged
when speculative preallocation occurs and untagged either via
truncate down or when post-EOF blocks are freed via release or
reclaim.
The tag management is intentionally not aggressive to prefer
simplicity over the complexity of handling all the corner cases
under which post-EOF blocks could be freed (i.e., forward
truncation, fallocate, write error conditions, etc.). This means
that a tagged inode may or may not have post-EOF blocks after a
period of time. The tag is eventually cleared when the inode is
released or reclaimed.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Eric Sandeen [Tue, 9 Oct 2012 19:11:45 +0000 (14:11 -0500)]
xfs: report projid32bit feature in geometry call
When xfs gained the projid32bit feature, it was never added to
the FSGEOMETRY ioctl feature flags, so it's not queryable without
this patch.
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 00:38:44 +0000 (11:38 +1100)]
xfs: fix reading of wrapped log data
Commit 4439647 ("xfs: reset buffer pointers before freeing them") in
3.0-rc1 introduced a regression when recovering log buffers that
wrapped around the end of log. The second part of the log buffer at
the start of the physical log was being read into the header buffer
rather than the data buffer, and hence recovery was seeing garbage
in the data buffer when it got to the region of the log buffer that
was incorrectly read.
Cc: <stable@vger.kernel.org> # 3.0.x, 3.2.x, 3.4.x 3.6.x Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 03:23:12 +0000 (14:23 +1100)]
xfs: fix buffer shudown reference count mismatch
When we shut down the filesystem, we have to unpin and free all the
buffers currently active in the CIL. To do this we unpin and remove
them in one operation as a result of a failed iclogbuf write. For
buffers, we do this removal via a simultated IO completion of after
marking the buffer stale.
At the time we do this, we have two references to the buffer - the
active LRU reference and the buf log item. The LRU reference is
removed by marking the buffer stale, and the active CIL reference is
by the xfs_buf_iodone() callback that is run by
xfs_buf_do_callbacks() during ioend processing (via the bp->b_iodone
callback).
However, ioend processing requires one more reference - that of the
IO that it is completing. We don't have this reference, so we free
the buffer prematurely and use it after it is freed. For buffers
marked with XBF_ASYNC, this leads to assert failures in
xfs_buf_rele() on debug kernels because the b_hold count is zero.
Fix this by making sure we take the necessary IO reference before
starting IO completion processing on the stale buffer, and set the
XBF_ASYNC flag to ensure that IO completion processing removes all
the active references from the buffer to ensure it is fully torn
down.
Cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 00:38:42 +0000 (11:38 +1100)]
xfs: don't vmap inode cluster buffers during free
Inode buffers do not need to be mapped as inodes are read or written
directly from/to the pages underlying the buffer. This fixes a
regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the
default behaviour").
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 00:38:41 +0000 (11:38 +1100)]
xfs: invalidate allocbt blocks moved to the free list
When we free a block from the alloc btree tree, we move it to the
freelist held in the AGFL and mark it busy in the busy extent tree.
This typically happens when we merge btree blocks.
Once the transaction is committed and checkpointed, the block can
remain on the free list for an indefinite amount of time. Now, this
isn't the end of the world at this point - if the free list is
shortened, the buffer is invalidated in the transaction that moves
it back to free space. If the buffer is allocated as metadata from
the free list, then all the modifications getted logged, and we have
no issues, either. And if it gets allocated as userdata direct from
the freelist, it gets invalidated and so will never get written.
However, during the time it sits on the free list, pressure on the
log can cause the AIL to be pushed and the buffer that covers the
block gets pushed for write. IOWs, we end up writing a freed
metadata block to disk. Again, this isn't the end of the world
because we know from the above we are only writing to free space.
The problem, however, is for validation callbacks. If the block was
on old btree root block, then the level of the block is going to be
higher than the current tree root, and so will fail validation.
There may be other inconsistencies in the block as well, and
currently we don't care because the block is in free space. Shutting
down the filesystem because a freed block doesn't pass write
validation, OTOH, is rather unfriendly.
So, make sure we always invalidate buffers as they move from the
free space trees to the free list so that we guarantee they never
get written to disk while on the free list.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Carlos Maiolino [Sat, 20 Oct 2012 14:08:19 +0000 (11:08 -0300)]
xfs: Update inode alloc comments
I found some out of date comments while studying the inode allocation
code, so I believe it's worth to have these comments updated.
It basically rewrites the comment regarding to "call_again" variable,
which is not used anymore, but instead, callers of xfs_ialloc() decides
if it needs to be called again relying only if ialloc_context is NULL or
not.
Also did some small changes in another comment that I thought to be
pertinent to the current behaviour of these functions and some alignment
on both comments.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Thu, 25 Oct 2012 06:22:30 +0000 (17:22 +1100)]
xfs: silence uninitialised f.file warning.
Uninitialised variable build warning introduced by 2903ff0 ("switch
simple cases of fget_light to fdget"), gcc is not smart enough to
work out that the variable is not used uninitialised, and the commit
removed the initialisation at declaration that the old variable had.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Tue, 9 Oct 2012 03:50:52 +0000 (14:50 +1100)]
xfs: growfs: don't read garbage for new secondary superblocks
When updating new secondary superblocks in a growfs operation, the
superblock buffer is read from the newly grown region of the
underlying device. This is not guaranteed to be zero, so violates
the underlying assumption that the unused parts of superblocks are
zero filled. Get a new buffer for these secondary superblocks to
ensure that the unused regions are zero filled correctly.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 5 Oct 2012 01:06:59 +0000 (11:06 +1000)]
xfs: move allocation stack switch up to xfs_bmapi_allocate
Switching stacks are xfs_alloc_vextent can cause deadlocks when we
run out of worker threads on the allocation workqueue. This can
occur because xfs_bmap_btalloc can make multiple calls to
xfs_alloc_vextent() and even if xfs_alloc_vextent() fails it can
return with the AGF locked in the current allocation transaction.
If we then need to make another allocation, and all the allocation
worker contexts are exhausted because the are blocked waiting for
the AGF lock, holder of the AGF cannot get it's xfs-alloc_vextent
work completed to release the AGF. Hence allocation effectively
deadlocks.
To avoid this, move the stack switch one layer up to
xfs_bmapi_allocate() so that all of the allocation attempts in a
single switched stack transaction occur in a single worker context.
This avoids the problem of an allocation being blocked waiting for
a worker thread whilst holding the AGF.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 5 Oct 2012 01:06:58 +0000 (11:06 +1000)]
xfs: introduce XFS_BMAPI_STACK_SWITCH
Certain allocation paths through xfs_bmapi_write() are in situations
where we have limited stack available. These are almost always in
the buffered IO writeback path when convertion delayed allocation
extents to real extents.
The current stack switch occurs for userdata allocations, which
means we also do stack switches for preallocation, direct IO and
unwritten extent conversion, even those these call chains have never
been implicated in a stack overrun.
Hence, let's target just the single stack overun offended for stack
switches. To do that, introduce a XFS_BMAPI_STACK_SWITCH flag that
the caller can pass xfs_bmapi_write() to indicate it should switch
stacks if it needs to do allocation.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:12 +0000 (21:56 +1100)]
xfs: only update the last_sync_lsn when a transaction completes
The log write code stamps each iclog with the current tail LSN in
the iclog header so that recovery knows where to find the tail of
thelog once it has found the head. Normally this is taken from the
first item on the AIL - the log item that corresponds to the oldest
active item in the log.
The problem is that when the AIL is empty, the tail lsn is dervied
from the the l_last_sync_lsn, which is the LSN of the last iclog to
be written to the log. In most cases this doesn't happen, because
the AIL is rarely empty on an active filesystem. However, when it
does, it opens up an interesting case when the transaction being
committed to the iclog spans multiple iclogs.
That is, the first iclog is stamped with the l_last_sync_lsn, and IO
is issued. Then the next iclog is setup, the changes copied into the
iclog (takes some time), and then the l_last_sync_lsn is stamped
into the header and IO is issued. This is still the same
transaction, so the tail lsn of both iclogs must be the same for log
recovery to find the entire transaction to be able to replay it.
The problem arises in that the iclog buffer IO completion updates
the l_last_sync_lsn with it's own LSN. Therefore, If the first iclog
completes it's IO before the second iclog is filled and has the tail
lsn stamped in it, it will stamp the LSN of the first iclog into
it's tail lsn field. If the system fails at this point, log recovery
will not see a complete transaction, so the transaction will no be
replayed.
The fix is simple - the l_last_sync_lsn is updated when a iclog
buffer IO completes, and this is incorrect. The l_last_sync_lsn
shoul dbe updated when a transaction is completed by a iclog buffer
IO. That is, only iclog buffers that have transaction commit
callbacks attached to them should update the l_last_sync_lsn. This
means that the last_sync_lsn will only move forward when a commit
record it written, not in the middle of a large transaction that is
rolling through multiple iclog buffers.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:11 +0000 (21:56 +1100)]
xfs: remove xfs_iget.c
The inode cache functions remaining in xfs_iget.c can be moved to xfs_icache.c
along with the other inode cache functions. This removes all functionality from
xfs_iget.c, so the file can simply be removed.
This move results in various functions now only having the scope of a single
file (e.g. xfs_inode_free()), so clean up all the definitions and exported
prototypes in xfs_icache.[ch] and xfs_inode.h appropriately.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:10 +0000 (21:56 +1100)]
xfs: move inode locking functions to xfs_inode.c
xfs_ilock() and friends really aren't related to the inode cache in
any way, so move them to xfs_inode.c with all the other inode
related functionality.
While doing this move, move the xfs_ilock() tracepoints to *before*
the lock is taken so that when a hang on a lock occurs we have
events to indicate which process and what inode we were trying to
lock when the hang occurred. This is much better than the current
silence we get on a hang...
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:09 +0000 (21:56 +1100)]
xfs: rename xfs_sync.[ch] to xfs_icache.[ch]
xfs_sync.c now only contains inode reclaim functions and inode cache
iteration functions. It is not related to sync operations anymore.
Rename to xfs_icache.c to reflect it's contents and prepare for
consolidation with the other inode cache file that exists
(xfs_iget.c).
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:08 +0000 (21:56 +1100)]
xfs: xfs_quiesce_attr() should quiesce the log like unmount
xfs_quiesce_attr() is supposed to leave the log empty with an
unmount record written. Right now it does not wait for the AIL to be
emptied before writing the unmount record, not does it wait for
metadata IO completion, either. Fix it to use the same method and
code as xfs_log_unmount().
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:07 +0000 (21:56 +1100)]
xfs: move xfs_quiesce_attr() into xfs_super.c
Both callers of xfs_quiesce_attr() are in xfs_super.c, and there's
nothing really sync-specific about this functionality so it doesn't
really matter where it lives. Move it to benext to it's callers, so
all the remount/sync_fs code is in the one place.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:06 +0000 (21:56 +1100)]
xfs: xfs_sync_fsdata is redundant
Why do we need to write the superblock to disk once we've written
all the data? We don't actually - the reasons for doing this are
lost in the mists of time, and go back to the way Irix used to drive
VFS flushing.
On linux, this code is only called from two contexts: remount and
.sync_fs. In the remount case, the call is followed by a metadata
sync, which unpins and writes the superblock. In the sync_fs case,
we only need to force the log to disk to ensure that the superblock
is correctly on disk, so we don't actually need to write it. Hence
the functionality is either redundant or superfluous and thus can be
removed.
Seeing as xfs_quiesce_data is essentially now just a log force,
remove it as well and fold the code back into the two callers.
Neither of them need the log covering check, either, as that is
redundant for the remount case, and unnecessary for the .sync_fs
case.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:05 +0000 (21:56 +1100)]
xfs: syncd workqueue is no more
With the syncd functions moved to the log and/or removed, the syncd
workqueue is the only remaining bit left. It is used by the log
covering/ail pushing work, as well as by the inode reclaim work.
Given how cheap workqueues are these days, give the log and inode
reclaim work their own work queues and kill the syncd work queue.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:04 +0000 (21:56 +1100)]
xfs: xfs_sync_data is redundant.
We don't do any data writeback from XFS any more - the VFS is
completely responsible for that, including for freeze. We can
replace the remaining caller with a VFS level function that
achieves the same thing, but without conflicting with current
writeback work.
This means we can remove the flush_work and xfs_flush_inodes() - the
VFS functionality completely replaces the internal flush queue for
doing this writeback work in a separate context to avoid stack
overruns.
This does have one complication - it cannot be called with page
locks held. Hence move the flushing of delalloc space when ENOSPC
occurs back up into xfs_file_aio_buffered_write when we don't hold
any locks that will stall writeback.
Unfortunately, writeback_inodes_sb_if_idle() is not sufficient to
trigger delalloc conversion fast enough to prevent spurious ENOSPC
whent here are hundreds of writers, thousands of small files and GBs
of free RAM. Hence we need to use sync_sb_inodes() to block callers
while we wait for writeback like the previous xfs_flush_inodes
implementation did.
That means we have to hold the s_umount lock here, but because this
call can nest inside i_mutex (the parent directory in the create
case, held by the VFS), we have to use down_read_trylock() to avoid
potential deadlocks. In practice, this trylock will succeed on
almost every attempt as unmount/remount type operations are
exceedingly rare.
Note: we always need to pass a count of zero to
generic_file_buffered_write() as the previously written byte count.
We only do this by accident before this patch by the virtue of ret
always being zero when there are no errors. Make this explicit
rather than needing to specifically zero ret in the ENOSPC retry
case.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Tested-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:03 +0000 (21:56 +1100)]
xfs: Bring some sanity to log unmounting
When unmounting the filesystem, there are lots of operations that
need to be done in a specific order, and they are spread across
across a couple of functions. We have to drain the AIL before we
write the unmount record, and we have to shut down the background
log work before we do either of them.
But this is all split haphazardly across xfs_unmountfs() and
xfs_log_unmount(). Move all the AIL flushing and log manipulations
to xfs_log_unmount() so that the responisbilities of each function
is clear and the operations they perform obvious.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:02 +0000 (21:56 +1100)]
xfs: sync work is now only periodic log work
The only thing the periodic sync work does now is flush the AIL and
idle the log. These are really functions of the log code, so move
the work to xfs_log.c and rename it appropriately.
The only wart that this leaves behind is the xfssyncd_centisecs
sysctl, otherwise the xfssyncd is dead. Clean up any comments that
related to xfssyncd to reflect it's passing.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:01 +0000 (21:56 +1100)]
xfs: don't run the sync work if the filesystem is read-only
If the filesystem is mounted or remounted read-only, stop the sync
worker that tries to flush or cover the log if the filesystem is
dirty. It's read-only, so it isn't dirty. Restart it on a remount,rw
as necessary. This avoids the need for RO checks in the work.
Similarly, stop the sync work when the filesystem is frozen, and
start it again when the filesysetm is thawed. This avoids the need
for special freeze checks in the work.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:00 +0000 (21:56 +1100)]
xfs: rationalise xfs_mount_wq users
Instead of starting and stopping background work on the xfs_mount_wq
all at the same time, separate them to where they really are needed
to start and stop.
The xfs_sync_worker, only needs to be started after all the mount
processing has completed successfully, while it needs to be stopped
before the log is unmounted.
The xfs_reclaim_worker is started on demand, and can be
stopped before the unmount process does it's own inode reclaim pass.
The xfs_flush_inodes work is run on demand, and so we really only
need to ensure that it has stopped running before we start
processing an unmount, freeze or remount,ro.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:55:59 +0000 (21:55 +1100)]
xfs: xfs_syncd_stop must die
xfs_syncd_start and xfs_syncd_stop tie a bunch of unrelated
functionailty together that actually have different start and stop
requirements. Kill these functions and open code the start/stop
methods for each of the background functions.
Subsequent patches will move the start/stop functions around to the
correct places to avoid races and shutdown issues.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Linus Torvalds [Sun, 14 Oct 2012 21:39:05 +0000 (14:39 -0700)]
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS update from Ralf Baechle:
"Cleanups and fixes for breakage that occured earlier during this merge
phase. Also a few patches that didn't make the first pull request.
Of those is the Alchemy work that merges code for many of the SOCs and
evaluation boards thus among other code shrinkage, reduces the number
of MIPS defconfigs by 5."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (22 commits)
MIPS: SNI: Switch RM400 serial to SCCNXP driver
MIPS: Remove unused empty_bad_pmd_table[] declaration.
MIPS: MT: Remove kspd.
MIPS: Malta: Fix section mismatch.
MIPS: asm-offset.c: Delete unused irq_cpustat_t struct offsets.
MIPS: Alchemy: Merge PB1100/1500 support into DB1000 code.
MIPS: Alchemy: merge PB1550 support into DB1550 code
MIPS: Alchemy: Single kernel for DB1200/1300/1550
MIPS: Optimize TLB refill for RI/XI configurations.
MIPS: proc: Cleanup printing of ASEs.
MIPS: Hardwire detection of DSP ASE Rev 2 for systems, as required.
MIPS: Add detection of DSP ASE Revision 2.
MIPS: Optimize pgd_init and pmd_init
MIPS: perf: Add perf functionality for BMIPS5000
MIPS: perf: Split the Kconfig option CONFIG_MIPS_MT_SMP
MIPS: perf: Remove unnecessary #ifdef
MIPS: perf: Add cpu feature bit for PCI (performance counter interrupt)
MIPS: perf: Change the "mips_perf_event" table unsupported indicator.
MIPS: Align swapper_pg_dir to 64K for better TLB Refill code.
vmlinux.lds.h: Allow architectures to add sections to the front of .bss
...
Linus Torvalds [Sun, 14 Oct 2012 20:39:34 +0000 (13:39 -0700)]
Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module signing support from Rusty Russell:
"module signing is the highlight, but it's an all-over David Howells frenzy..."
Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG.
* 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits)
X.509: Fix indefinite length element skip error handling
X.509: Convert some printk calls to pr_devel
asymmetric keys: fix printk format warning
MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking
MODSIGN: Make mrproper should remove generated files.
MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs
MODSIGN: Use the same digest for the autogen key sig as for the module sig
MODSIGN: Sign modules during the build process
MODSIGN: Provide a script for generating a key ID from an X.509 cert
MODSIGN: Implement module signature checking
MODSIGN: Provide module signing public keys to the kernel
MODSIGN: Automatically generate module signing keys if missing
MODSIGN: Provide Kconfig options
MODSIGN: Provide gitignore and make clean rules for extra files
MODSIGN: Add FIPS policy
module: signature checking hook
X.509: Add a crypto key parser for binary (DER) X.509 certificates
MPILIB: Provide a function to read raw data into an MPI
X.509: Add an ASN.1 decoder
X.509: Add simple ASN.1 grammar compiler
...
Matt Fleming [Fri, 12 Oct 2012 10:19:59 +0000 (11:19 +0100)]
x86, boot: Explicitly include autoconf.h for hostprogs
The hostprogs need access to the CONFIG_* symbols found in
include/generated/autoconf.h. But commit abbf1590de22 ("UAPI: Partition
the header include path sets and add uapi/ header directories") replaced
$(LINUXINCLUDE) with $(USERINCLUDE) which doesn't contain the necessary
include paths.
This has the undesirable effect of breaking the EFI boot stub because
the #ifdef CONFIG_EFI_STUB code in arch/x86/boot/tools/build.c is
never compiled.
It should also be noted that because $(USERINCLUDE) isn't exported by
the top-level Makefile it's actually empty in arch/x86/boot/Makefile.
Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 14 Oct 2012 00:18:53 +0000 (17:18 -0700)]
Merge branch 'late-for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM update from Russell King:
"This is the final round of stuff for ARM, left until the end of the
merge window to reduce the number of conflicts. This set contains the
ARM part of David Howells UAPI changes, and a fix to the ordering of
'select' statements in ARM Kconfig files (see the appropriate commit
for why this happened - thanks to Andrew Morton for pointing out the
problem.)
I've left this as long as I dare for this window to avoid conflicts,
and I regenerated the config patch yesterday, posting it to our
mailing list for review and testing. I have several acks which
include successful test reports for it.
However, today I notice we've got new conflicts with previously unseen
code... though that conflict should be trivial (it's my changes vs a
one liner.)"
* 'late-for-linus' of git://git.linaro.org/people/rmk/linux-arm:
ARM: config: make sure that platforms are ordered by option string
ARM: config: sort select statements alphanumerically
UAPI: (Scripted) Disintegrate arch/arm/include/asm
Fix up fairly conflict in arch/arm/Kconfig (the select re-organization
vs recent addition of GENERIC_KERNEL_EXECVE)
Linus Torvalds [Sat, 13 Oct 2012 20:28:32 +0000 (13:28 -0700)]
Merge tag 'disintegrate-main-20121013' of git://git.infradead.org/users/dhowells/linux-headers
Pull UAPI disintegration for include/linux/{,byteorder/}*.h from David Howells:
"The patches contained herein do the following:
(1) Remove kernel-only stuff in linux/ppp-comp.h from the UAPI. I checked
this with Paul Mackerras before I created the patch and he suggested some
extra bits to unexport.
(2) Remove linux/blk_types.h entirely from the UAPI as none of it is userspace
applicable, and remove from the UAPI that part of linux/fs.h that was the
reason for linux/blk_types.h being exported in the first place. I
discussed this with Jens Axboe before creating the patch.
(3) The big patch of the series to disintegrate include/linux/*.h as a unit.
This could be split up, though there would be collisions in moving stuff
between the two Kbuild files when the parts are merged as that file is
sorted alphabetically rather than being grouped by subsystem.
Of this set of headers, 17 files have changed in the UAPI exported region
since the 4th and only 8 since the 9th so there isn't much change in this
area - as one might expect.
It should be pretty obvious and straightforward if it does come to fixing
up: stuff in __KERNEL__ guards stays where it is and stuff outside moves
to the same file in the include/uapi/linux/ directory.
If a new file appears then things get a bit more complicated as the
"headers +=" line has to move to include/uapi/linux/Kbuild. Only one new
file has appeared since the 9th and I judge this type of event relatively
unlikely.
(4) A patch to disintegrate include/linux/byteorder/*.h as a unit.
Signed-off-by: David Howells <dhowells@redhat.com>"
* tag 'disintegrate-main-20121013' of git://git.infradead.org/users/dhowells/linux-headers:
UAPI: (Scripted) Disintegrate include/linux/byteorder
UAPI: (Scripted) Disintegrate include/linux
UAPI: Unexport linux/blk_types.h
UAPI: Unexport part of linux/ppp-comp.h
Linus Torvalds [Sat, 13 Oct 2012 20:26:39 +0000 (13:26 -0700)]
Merge tag 'disintegrate-spi-20121009' of git://git.infradead.org/users/dhowells/linux-headers
Pull spi UAPI disintegration from David Howells:
"This is to complete part of the Userspace API (UAPI) disintegration
for which the preparatory patches were pulled recently. After these
patches, userspace headers will be segregated into:
include/uapi/linux/.../foo.h
for the userspace interface stuff, and:
include/linux/.../foo.h
for the strictly kernel internal stuff.
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Grant Likely <grant.likely@secretlab.ca>"
* tag 'disintegrate-spi-20121009' of git://git.infradead.org/users/dhowells/linux-headers:
UAPI: (Scripted) Disintegrate include/linux/spi
Linus Torvalds [Sat, 13 Oct 2012 20:23:39 +0000 (13:23 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace compile fixes from Eric W Biederman:
"This tree contains three trivial fixes. One compiler warning, one
thinko fix, and one build fix"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
btrfs: Fix compilation with user namespace support enabled
userns: Fix posix_acl_file_xattr_userns gid conversion
userns: Properly print bluetooth socket uids
Linus Torvalds [Sat, 13 Oct 2012 20:22:01 +0000 (13:22 -0700)]
Merge tag 'md-3.7' of git://neil.brown.name/md
Pull md updates from NeilBrown:
- "discard" support, some dm-raid improvements and other assorted bits
and pieces.
* tag 'md-3.7' of git://neil.brown.name/md: (29 commits)
md: refine reporting of resync/reshape delays.
md/raid5: be careful not to resize_stripes too big.
md: make sure manual changes to recovery checkpoint are saved.
md/raid10: use correct limit variable
md: writing to sync_action should clear the read-auto state.
Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races
md/raid5: make sure to_read and to_write never go negative.
md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write.
md/raid5: protect debug message against NULL derefernce.
md/raid5: add some missing locking in handle_failed_stripe.
MD: raid5 avoid unnecessary zero page for trim
MD: raid5 trim support
md/bitmap:Don't use IS_ERR to judge alloc_page().
md/raid1: Don't release reference to device while handling read error.
raid: replace list_for_each_continue_rcu with new interface
add further __init annotations to crypto/xor.c
DM RAID: Fix for "sync" directive ineffectiveness
DM RAID: Fix comparison of index and quantity for "rebuild" parameter
DM RAID: Add rebuild capability for RAID10
DM RAID: Move 'rebuild' checking code to its own function
...
Russell King [Fri, 12 Oct 2012 13:20:52 +0000 (14:20 +0100)]
ARM: config: make sure that platforms are ordered by option string
The large platform selection choice should be sorted by option string
so it's easy to find the platform you're looking for. Fix the few
options which are out of this order.
Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is a pet peeve of mine. Any time there's a long list of items
(header file inclusions, kconfig entries, array initalisers, etc) and
someone wants to add a new item, they *always* go and stick it at the
end of the list.
Guys, don't do this. Either put the new item into a randomly-chosen
position or, probably better, alphanumerically sort the list.
lets sort all our select statements alphanumerically. This commit was
created by the following perl:
while (<>) {
while (/\\\s*$/) {
$_ .= <>;
}
undef %selects if /^\s*config\s+/;
if (/^\s+select\s+(\w+).*/) {
if (defined($selects{$1})) {
if ($selects{$1} eq $_) {
print STDERR "Warning: removing duplicated $1 entry\n";
} else {
print STDERR "Error: $1 differently selected\n".
"\tOld: $selects{$1}\n".
"\tNew: $_\n";
exit 1;
}
}
$selects{$1} = $_;
next;
}
if (%selects and (/^\s*$/ or /^\s+help/ or /^\s+---help---/ or
/^endif/ or /^endchoice/)) {
foreach $k (sort (keys %selects)) {
print "$selects{$k}";
}
undef %selects;
}
print;
}
if (%selects) {
foreach $k (sort (keys %selects)) {
print "$selects{$k}";
}
}
and they are identical duplicates, hence the shrinkage in the diffstat
of two lines.
We have four testers reporting success of this change (Tony, Stephen,
Linus and Sekhar.)
Acked-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Stephen Warren <swarren@nvidia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
David Howells [Sat, 13 Oct 2012 09:46:48 +0000 (10:46 +0100)]
UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
David Howells [Sat, 13 Oct 2012 09:45:06 +0000 (10:45 +0100)]
UAPI: Unexport linux/blk_types.h
It seems that was linux/blk_types.h incorrectly exported to fix up some missing
bits required by the exported parts of linux/fs.h (READ, WRITE, READA, etc.).
So unexport linux/blk_types.h and unexport the relevant bits of linux/fs.h.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jens Axboe <jaxboe@fusionio.com>
cc: Tejun Heo <tj@kernel.org>
cc: Al Viro <viro@ZenIV.linux.org.uk>
Jonas Bonn [Sat, 13 Oct 2012 05:38:37 +0000 (07:38 +0200)]
Merge tag 'disintegrate-openrisc-20121009' of git://git.infradead.org/users/dhowells/linux-headers
UAPI Disintegration 2012-10-09
* tag 'disintegrate-openrisc-20121009' of git://git.infradead.org/users/dhowells/linux-headers:
UAPI: (Scripted) Disintegrate arch/openrisc/include/asm
Linus Torvalds [Sat, 13 Oct 2012 02:29:00 +0000 (11:29 +0900)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull TPM bugfixes from James Morris.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
tpm: Propagate error from tpm_transmit to fix a timeout hang
driver/char/tpm: fix regression causesd by ppi
Linus Torvalds [Sat, 13 Oct 2012 02:27:59 +0000 (11:27 +0900)]
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
Pull ACPI & Thermal updates from Len Brown:
"The generic Linux thermal layer is gaining some new capabilities
(generic cooling via cpufreq) and some new customers (ARM).
Also, an ACPI EC bug fix plus a regression fix."
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (30 commits)
tools/power/acpi/acpidump: remove duplicated include from acpidump.c
ACPI idle, CPU hotplug: Fix NULL pointer dereference during hotplug
cpuidle / ACPI: fix potential NULL pointer dereference
ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
ACPI: EC: Make the GPE storm threshold a module parameter
thermal: Exynos: Fix NULL pointer dereference in exynos_unregister_thermal()
Thermal: Fix bug on cpu_cooling, cooling device's id conflict problem.
thermal: exynos: Use devm_* functions
ARM: exynos: add thermal sensor driver platform data support
thermal: exynos: register the tmu sensor with the kernel thermal layer
thermal: exynos5: add exynos5250 thermal sensor driver support
hwmon: exynos4: move thermal sensor driver to driver/thermal directory
thermal: add generic cpufreq cooling implementation
Fix a build error.
thermal: Fix potential NULL pointer accesses
thermal: add Renesas R-Car thermal sensor support
thermal: fix potential out-of-bounds memory access
Thermal: Introduce locking for cdev.thermal_instances list.
Thermal: Unify the code for both active and passive cooling
Thermal: Introduce simple arbitrator for setting device cooling state
...
Linus Torvalds [Sat, 13 Oct 2012 02:25:41 +0000 (11:25 +0900)]
Merge tag 'for-3.7' of git://openrisc.net/jonas/linux
Pull OpenRISC updates from Jonas Bonn:
"Fixups for some corner cases, build issues, and some obvious bugs in
IRQ handling. No major changes."
* tag 'for-3.7' of git://openrisc.net/jonas/linux:
openrisc: mask interrupts in irq_mask_ack function
openrisc: fix typos in comments and warnings
openrisc: PIC should act on domain-local irqs
openrisc: Make cpu_relax() invoke barrier()
audit: define AUDIT_ARCH_OPENRISC
openrisc: delay: fix handling of counter overflow
openrisc: delay: fix loops calculation for __const_udelay