In preparation for combined pquota/gquota support, for the sake
of readability, change the macro to an inline function.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

In preparation for combined pquota/gquota support, define
a new function to check if the given inode is a quota inode.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

For CRC enabled filesystems, add support for the monotonic inode
version change counter that is needed by protocols like NFSv4 for
determining if the inode has changed in any way at all between two
unrelated operations on the inode.

This bumps the change count the first time an inode is dirtied in a
transaction. Since all modifications to the inode are logged, this
will catch all changes that are made to the inode, including
timestamp updates that occur during data writes.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Replace the use of buffer based logging of inode initialisation,
uses the new logical form to describe the range to be initialised
in recovery. We continue to "log" the inode buffers to push them
into the AIL and ensure that the inode create transaction is not
removed from the log before the inode buffers are written to disk.

Update the transaction identifier and reservations to match the
changed implementation.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When we find a icreate transaction, we need to get and initialise
the buffers in the range that has been passed. Extract and verify
the information in the item record, then loop over the range
initialising and issuing the buffer writes delayed.

Support an arbitrary size range to initialise so that in
future when we allocate inodes in much larger chunks all kernels
that understand this transaction can still recover them.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Define the log and space transaction sizes. Factor the current
create log reservation macro into the two logical halves and reuse
one half for the new icreate transactions. The icreate transaction
is transparent to all the high level create code - the
pre-calculated reservations will correctly set the reservations
dependent on whether the filesystem supports the icreate
transaction.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

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

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

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

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

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

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

And "ordered log vector" is a log vector that is used for
tracking a log item through the CIL and into the AIL as part of the
log checkpointing. These ordered log vectors are special in that
they are not written to to journal in any way, and are not accounted
to the checkpoint being written.

The reason for this behaviour is to allow operations to attach items
to transactions and have them follow the normal transactional
lifecycle without actually having to write them to the journal. This
allows logging of items that track high level logical changes and
writing them to the log, while the physical items being modified
pass through into the AIL and pin the tail of the log (and therefore
the logical item in the log) until all the modified items are
physically written to disk.

IOWs, it allows us to write metadata without physically logging
every individual change but still maintain the full transactional
integrity guarantees we currently have w.r.t. crash recovery.

This change modifies some of the CIL item insertion loops, as
ordered log vectors introduce some new constraints as they don't
track any data. One advantage of this change is that it combines
two log vector chain walks into a single pass, so there is less
overhead in the transaction commit pass as well. It also kills some
unused code in the log vector walk loop when committing the CIL.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Long ago, bulkstat used to read inodes directly from the backing
buffer for speed. This had the unfortunate problem of being cache
incoherent with unlinks, and so xfs_ifree() had to mark the inode
as free directly in the backing buffer. bulkstat was changed some
time ago to use inode cache coherent lookups, and so will never see
unlinked inodes in it's lookups. Hence xfs_ifree() does not need to
touch the inode backing buffer anymore.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When we are allocating a new inode, we read the inode cluster off
disk to increment the generation number. We are already using a
random generation number for newly allocated inodes, so if we are not
using the ikeep mode, we can just generate a new generation number
when we initialise the newly allocated inode.

This avoids the need for reading the inode buffer during inode
creation. This will speed up allocation of inodes in cold, partially
allocated clusters as they will no longer need to be read from disk
during allocation. It will also reduce the CPU overhead of inode
allocation by not having the process the buffer read, even on cache
hits.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Dedicated small file workloads have been seeing significant free
space fragmentation causing premature inode allocation failure
when large inode sizes are in use. A particular test case showed
that a workload that runs to a real ENOSPC on 256 byte inodes would
fail inode allocation with ENOSPC about about 80% full with 512 byte
inodes, and at about 50% full with 1024 byte inodes.

The same workload, when run with -o allocsize=4096 on 1024 byte
inodes would run to being 100% full before giving ENOSPC. That is,
no freespace fragmentation at all.

The issue was caused by the specific IO pattern the application had
- the framework it was using did not support direct IO, and so it
was emulating it by using fadvise(DONT_NEED). The result was that
the data was getting written back before the speculative prealloc
had been trimmed from memory by the close(), and so small single
block files were being allocated with 2 blocks, and then having one
truncated away. The result was lots of small 4k free space extents,
and hence each new 8k allocation would take another 8k from
contiguous free space and turn it into 4k of allocated space and 4k
of free space.

Hence inode allocation, which requires contiguous, aligned
allocation of 16k (256 byte inodes), 32k (512 byte inodes) or 64k
(1024 byte inodes) can fail to find sufficiently large freespace and
hence fail while there is still lots of free space available.

There's a simple fix for this, and one that has precendence in the
allocator code already - don't do speculative allocation unless the
size of the file is larger than a certain size. In this case, that
size is the minimum default preallocation size:
mp->m_writeio_blocks. And to keep with the concept of being nice to
people when the files are still relatively small, cap the prealloc
to mp->m_writeio_blocks until the file goes over a stripe unit is
size, at which point we'll fall back to the current behaviour based
on the last extent size.

This will effectively turn off speculative prealloc for very small
files, keep preallocation low for small files, and behave as it
currently does for any file larger than a stripe unit. This
completely avoids the freespace fragmentation problem this
particular IO pattern was causing.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Similar to bulkstat inode chunk readahead, we need to plug directory
data buffer readahead during getdents to ensure that we can merge
adjacent readahead requests and sort out of order requests optimally
before they are dispatched. This improves the readahead efficiency
and reduces the IO load it generates as the IO patterns are
significantly better for both contiguous and fragmented directories.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

I was running some tests on bulkstat on CRC enabled filesystems when
I noticed that all the IO being issued was 8k in size, regardless of
the fact taht we are issuing sequential 8k buffers for inodes
clusters. The IO size should be 16k for 256 byte inodes, and 32k for
512 byte inodes, but this wasn't happening.

blktrace showed that there was an explict plug and unplug happening
around each readahead IO from _xfs_buf_ioapply, and the unplug was
causing the IO to be issued immediately. Hence no opportunity was
being given to the elevator to merge adjacent readahead requests and
dispatch them as a single IO.

Add plugging around the inode chunk readahead dispatch loop in
bulkstat to ensure that we don't unplug the queue between adjacent
inode buffer readahead IOs and so we get fewer, larger IO requests
hitting the storage subsystem for bulkstat.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Remove dead function prototype xfs_sync_inode_grab()
from xfs_icache.h.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

This patch clean out the left function variable as it is
useless to xfs_ialloc_get_rec().
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

xfs_swap_extents_check_format() contains checks to make sure that
original and the temporary files during defrag are compatible;
Gabriel VLASIU ran into a case where xfs_fsr returned EINVAL
because the tests found the btree root to be of size 120,
while the fork offset was only 104; IOW, they overlapped.

However, this is just due to an error in the
xfs_swap_extents_check_format() tests, because it is checking
the in-memory btree root size against the on-disk fork offset.
We should be checking the on-disk sizes in both cases.

This patch adds a new macro to calculate this size, and uses
it in the tests.

With this change, the filesystem image provided by Gabriel
allows for proper file degragmentation.
Reported-by: NGabriel VLASIU <gabriel@vlasiu.net>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

XFS_MOUNT_RETERR is going to be set at xfs_parseargs() if
mp->m_dalign is enabled, so any time we enter "if (mp->m_dalign)"
branch in xfs_update_alignment(), XFS_MOUNT_RETERR is set and so
we always be emitting a warning and returning an error.

Hence, we can remove it and get rid of a couple of redundant
check up against it at xfs_upate_alignment().

Thanks Dave Chinner for the suggestions of simplify the code
in xfs_parseargs().
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

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

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

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

For FIEMAP ioctl(2), if an extent is in delayed allocation
state, we need to return the FIEMAP_EXTENT_UNKNOWN flag except
the FIEMAP_EXTENT_DELALLOC because its data location is unknown.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Adding an extended attribute to a symbolic link can force that
link to an remote extent. xfs_inactive() incorrectly assumes
that any symbolic link small enough to be in the inode core
is incore, resulting in the remote extent to not be removed.
xfs_ifree() will assert on presence of this leaked remote extent.
Signed-off-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Remove struct xfs_chash from struct xfs_mount as there is no user of
it nowadays.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

As per the mount man page, sunit and swidth can be changed via
mount options.  For XFS, on the face of it, those options seems
works if the specified alignments is properly, e.g.
# mount -o sunit=4096,swidth=8192 /dev/sdb1 /mnt
# mount | grep sdb1
/dev/sdb1 on /mnt type xfs (rw,sunit=4096,swidth=8192)

However, neither sunit nor swidth is shown from the xfs_info output.
# xfs_info /mnt
meta-data=/dev/sdb1    isize=256    agcount=4, agsize=262144 blks
         =             sectsz=512   attr=2
data     =             bsize=4096   blocks=1048576, imaxpct=25
         =             sunit=0      swidth=0 blks
		       ^^^^^^^^^^^^^^^^^^^^^^^^^^
naming   =version 2    bsize=4096   ascii-ci=0
log      =internal     bsize=4096   blocks=2560, version=2
         =             sectsz=512   sunit=0 blks, lazy-count=1
realtime =none         extsz=4096   blocks=0, rtextents=0

The reason is that the alignment can only be changed if the relevant
super block is already configured with alignments, otherwise, the
given value is silently ignored.

With this fix, the attempt to mount a storage without strip alignment
setup on a super block will get an error with a warning in syslog to
indicate the true cause, e.g.
# mount -o sunit=4096,swidth=8192 /dev/sdb1 /mnt
mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
	dmesg | tail  or so
.......
XFS (sdb1): cannot change alignment: superblock does not support data
alignment
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Cc: Mark Tinguely <tinguely@sgi.com>
Cc: Dave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Commit eab4e633 "xfs: uncached buffer reads need to return an error".

Remove redundant error variable, using the function level error variable
to store bp->b_error instead.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

This typedef is unnecessary and should just be removed.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Unfortunately, we cannot guarantee that items logged multiple times
and replayed by log recovery do not take objects back in time. When
they are taken back in time, the go into an intermediate state which
is corrupt, and hence verification that occurs on this intermediate
state causes log recovery to abort with a corruption shutdown.

Instead of causing a shutdown and unmountable filesystem, don't
verify post-recovery items before they are written to disk. This is
less than optimal, but there is no way to detect this issue for
non-CRC filesystems If log recovery successfully completes, this
will be undone and the object will be consistent by subsequent
transactions that are replayed, so in most cases we don't need to
take drastic action.

For CRC enabled filesystems, leave the verifiers in place - we need
to call them to recalculate the CRCs on the objects anyway. This
recovery problem can be solved for such filesystems - we have a LSN
stamped in all metadata at writeback time that we can to determine
whether the item should be replayed or not. This is a separate piece
of work, so is not addressed by this patch.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

For CRC enabled filesystems, the BMBT is rooted in an inode, so it
passes through a different code path on root splits than the
freespace and inode btrees. This is much less traversed by xfstests
than the other trees. When testing on a 1k block size filesystem,
I've been seeing ASSERT failures in generic/234 like:

XFS: Assertion failed: cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_private.b.allocated == 0, file: fs/xfs/xfs_btree.c, line: 317

which are generally preceded by a lblock check failure. I noticed
this in the bmbt stats:

$ pminfo -f xfs.btree.block_map

xfs.btree.block_map.lookup
    value 39135

xfs.btree.block_map.compare
    value 268432

xfs.btree.block_map.insrec
    value 15786

xfs.btree.block_map.delrec
    value 13884

xfs.btree.block_map.newroot
    value 2

xfs.btree.block_map.killroot
    value 0
.....

Very little coverage of root splits and merges. Indeed, on a 4k
filesystem, block_map.newroot and block_map.killroot are both zero.
i.e. the code is not exercised at all, and it's the only generic
btree infrastructure operation that is not exercised by a default run
of xfstests.

Turns out that on a 1k filesystem, generic/234 accounts for one of
those two root splits, and that is somewhat of a smoking gun. In
fact, it's the same problem we saw in the directory/attr code where
headers are memcpy()d from one block to another without updating the
self describing metadata.

Simple fix - when copying the header out of the root block, make
sure the block number is updated correctly.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Michael L. Semon has been testing CRC patches on a 32 bit system and
been seeing assert failures in the directory code from xfs/080.
Thanks to Michael's heroic efforts with printk debugging, we found
that the problem was that the last free space being left in the
directory structure was too small to fit a unused tag structure and
it was being corrupted and attempting to log a region out of bounds.
Hence the assert failure looked something like:

.....
#5 calling xfs_dir2_data_log_unused() 36 32
#1 4092 4095 4096
#2 8182 8183 4096
XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568

Where #1 showed the first region of the dup being logged (i.e. the
last 4 bytes of a directory buffer) and #2 shows the corrupt values
being calculated from the length of the dup entry which overflowed
the size of the buffer.

It turns out that the problem was not in the logging code, nor in
the freespace handling code. It is an initial condition bug that
only shows up on 32 bit systems. When a new buffer is initialised,
where's the freespace that is set up:

[  172.316249] calling xfs_dir2_leaf_addname() from xfs_dir_createname()
[  172.316346] #9 calling xfs_dir2_data_log_unused()
[  172.316351] #1 calling xfs_trans_log_buf() 60 63 4096
[  172.316353] #2 calling xfs_trans_log_buf() 4094 4095 4096

Note the offset of the first region being logged? It's 60 bytes into
the buffer. Once I saw that, I pretty much knew that the bug was
going to be caused by this.

Essentially, all direct entries are rounded to 8 bytes in length,
and all entries start with an 8 byte alignment. This means that we
can decode inplace as variables are naturally aligned. With the
directory data supposedly starting on a 8 byte boundary, and all
entries padded to 8 bytes, the minimum freespace in a directory
block is supposed to be 8 bytes, which is large enough to fit a
unused data entry structure (6 bytes in size). The fact we only have
4 bytes of free space indicates a directory data block alignment
problem.

And what do you know - there's an implicit hole in the directory
data block header for the CRC format, which means the header is 60
byte on 32 bit intel systems and 64 bytes on 64 bit systems. Needs
padding. And while looking at the structures, I found the same
problem in the attr leaf header. Fix them both.

Note that this only affects 32 bit systems with CRCs enabled.
Everything else is just fine. Note that CRC enabled filesystems created
before this fix on such systems will not be readable with this fix
applied.
Reported-by: NMichael L. Semon <mlsemon35@gmail.com>
Debugged-by: NMichael L. Semon <mlsemon35@gmail.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The limit of 25 ACL entries is arbitrary, but baked into the on-disk
format.  For version 5 superblocks, increase it to the maximum nuber
of ACLs that can fit into a single xattr.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinuguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

attr2 format is always enabled for v5 superblock filesystems, so the
mount options to enable or disable it need to be cause mount errors.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The inode unlinked list manipulations operate directly on the inode
buffer, and so bypass the inode CRC calculation mechanisms. Hence an
inode on the unlinked list has an invalid CRC. Fix this by
recalculating the CRC whenever we modify an unlinked list pointer in
an inode, ncluding during log recovery. This is trivial to do and
results in  unlinked list operations always leaving a consistent
inode in the buffer.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

There are several constraints that inode allocation and unlink
logging impose on log recovery. These all stem from the fact that
inode alloc/unlink are logged in buffers, but all other inode
changes are logged in inode items. Hence there are ordering
constraints that recovery must follow to ensure the correct result
occurs.

As it turns out, this ordering has been working mostly by chance
than good management. The existing code moves all buffers except
cancelled buffers to the head of the list, and everything else to
the tail of the list. The problem with this is that is interleaves
inode items with the buffer cancellation items, and hence whether
the inode item in an cancelled buffer gets replayed is essentially
left to chance.

Further, this ordering causes problems for log recovery when inode
CRCs are enabled. It typically replays the inode unlink buffer long before
it replays the inode core changes, and so the CRC recorded in an
unlink buffer is going to be invalid and hence any attempt to
validate the inode in the buffer is going to fail. Hence we really
need to enforce the ordering that the inode alloc/unlink code has
expected log recovery to have since inode chunk de-allocation was
introduced back in 2003...
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When invalidating an attribute leaf block block, there might be
remote attributes that it points to. With the recent rework of the
remote attribute format, we have to make sure we calculate the
length of the attribute correctly. We aren't doing that in
xfs_attr3_leaf_inactive(), so fix it.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinuguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Calculating dquot CRCs when the backing buffer is written back just
doesn't work reliably. There are several places which manipulate
dquots directly in the buffers, and they don't calculate CRCs
appropriately, nor do they always set the buffer up to calculate
CRCs appropriately.

Firstly, if we log a dquot buffer (e.g. during allocation) it gets
logged without valid CRC, and so on recovery we end up with a dquot
that is not valid.

Secondly, if we recover/repair a dquot, we don't have a verifier
attached to the buffer and hence CRCs are not calculated on the way
down to disk.

Thirdly, calculating the CRC after we've changed the contents means
that if we re-read the dquot from the buffer, we cannot verify the
contents of the dquot are valid, as the CRC is invalid.

So, to avoid all the dquot CRC errors that are being detected by the
read verifier, change to using the same model as for inodes. That
is, dquot CRCs are calculated and written to the backing buffer at
the time the dquot is flushed to the backing buffer. If we modify
the dquot directly in the backing buffer, calculate the CRC
immediately after the modification is complete. Hence the dquot in
the on-disk buffer should always have a valid CRC.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When the directory freespace index grows to a second block (2017
4k data blocks in the directory), the initialisation of the second
new block header goes wrong. The write verifier fires a corruption
error indicating that the block number in the header is zero. This
was being tripped by xfs/110.

The problem is that the initialisation of the new block is done just
fine in xfs_dir3_free_get_buf(), but the caller then users a dirv2
structure to zero on-disk header fields that xfs_dir3_free_get_buf()
has already zeroed. These lined up with the block number in the dir
v3 header format.

While looking at this, I noticed that the struct xfs_dir3_free_hdr()
had 4 bytes of padding in it that wasn't defined as padding or being
zeroed by the initialisation. Add a pad field declaration and fully
zero the on disk and in-core headers in xfs_dir3_free_get_buf() so
that this is never an issue in the future. Note that this doesn't
change the on-disk layout, just makes the 32 bits of padding in the
layout explicit.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

XFS has failed to kill suid/sgid bits correctly when truncating
files of non-zero size since commit c4ed4243 ("xfs: split
xfs_setattr") introduced in the 3.1 kernel. Fix it.

Fix it.

cc: stable kernel <stable@vger.kernel.org>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Currently userspace has no way of determining that a filesystem is
CRC enabled. Add a flag to the XFS_IOC_FSGEOMETRY ioctl output to
indicate that the filesystem has v5 superblock support enabled.
This will allow xfs_info to correctly report the state of the
filesystem.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Currently, swapping extents from one inode to another is a simple
act of switching data and attribute forks from one inode to another.
This, unfortunately in no longer so simple with CRC enabled
filesystems as there is owner information embedded into the BMBT
blocks that are swapped between inodes. Hence swapping the forks
between inodes results in the inodes having mapping blocks that
point to the wrong owner and hence are considered corrupt.

To fix this we need an extent tree block or record based swap
algorithm so that the BMBT block owner information can be updated
atomically in the swap transaction. This is a significant piece of
new work, so for the moment simply don't allow swap extent
operations to succeed on CRC enabled filesystems.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

A long time ago in a galaxy far away....

.. the was a commit made to fix some ilinux specific "fragmented
buffer" log recovery problem:

http://oss.sgi.com/cgi-bin/gitweb.cgi?p=archive/xfs-import.git;a=commitdiff;h=b29c0bece51da72fb3ff3b61391a391ea54e1603

That problem occurred when a contiguous dirty region of a buffer was
split across across two pages of an unmapped buffer. It's been a
long time since that has been done in XFS, and the changes to log
the entire inode buffers for CRC enabled filesystems has
re-introduced that corner case.

And, of course, it turns out that the above commit didn't actually
fix anything - it just ensured that log recovery is guaranteed to
fail when this situation occurs. And now for the gory details.

xfstest xfs/085 is failing with this assert:

XFS (vdb): bad number of regions (0) in inode log format
XFS: Assertion failed: 0, file: fs/xfs/xfs_log_recover.c, line: 1583

Largely undocumented factoid #1: Log recovery depends on all log
buffer format items starting with this format:

struct foo_log_format {
	__uint16_t	type;
	__uint16_t	size;
	....

As recoery uses the size field and assumptions about 32 bit
alignment in decoding format items.  So don't pay much attention to
the fact log recovery thinks that it decoding an inode log format
item - it just uses them to determine what the size of the item is.

But why would it see a log format item with a zero size? Well,
luckily enough xfs_logprint uses the same code and gives the same
error, so with a bit of gdb magic, it turns out that it isn't a log
format that is being decoded. What logprint tells us is this:

Oper (130): tid: a0375e1a  len: 28  clientid: TRANS  flags: none
BUF:  #regs: 2   start blkno: 144 (0x90)  len: 16  bmap size: 2  flags: 0x4000
Oper (131): tid: a0375e1a  len: 4096  clientid: TRANS  flags: none
BUF DATA
----------------------------------------------------------------------------
Oper (132): tid: a0375e1a  len: 4096  clientid: TRANS  flags: none
xfs_logprint: unknown log operation type (4e49)
**********************************************************************
* ERROR: data block=2                                                 *
**********************************************************************

That we've got a buffer format item (oper 130) that has two regions;
the format item itself and one dirty region. The subsequent region
after the buffer format item and it's data is them what we are
tripping over, and the first bytes of it at an inode magic number.
Not a log opheader like there is supposed to be.

That means there's a problem with the buffer format item. It's dirty
data region is 4096 bytes, and it contains - you guessed it -
initialised inodes. But inode buffers are 8k, not 4k, and we log
them in their entirety. So something is wrong here. The buffer
format item contains:

(gdb) p /x *(struct xfs_buf_log_format *)in_f
$22 = {blf_type = 0x123c, blf_size = 0x2, blf_flags = 0x4000,
       blf_len = 0x10, blf_blkno = 0x90, blf_map_size = 0x2,
       blf_data_map = {0xffffffff, 0xffffffff, .... }}

Two regions, and a signle dirty contiguous region of 64 bits.  64 *
128 = 8k, so this should be followed by a single 8k region of data.
And the blf_flags tell us that the type of buffer is a
XFS_BLFT_DINO_BUF. It contains inodes. And because it doesn't have
the XFS_BLF_INODE_BUF flag set, that means it's an inode allocation
buffer. So, it should be followed by 8k of inode data.

But we know that the next region has a header of:

(gdb) p /x *ohead
$25 = {oh_tid = 0x1a5e37a0, oh_len = 0x100000, oh_clientid = 0x69,
       oh_flags = 0x0, oh_res2 = 0x0}

and so be32_to_cpu(oh_len) = 0x1000 = 4096 bytes. It's simply not
long enough to hold all the logged data. There must be another
region. There is - there's a following opheader for another 4k of
data that contains the other half of the inode cluster data - the
one we assert fail on because it's not a log format header.

So why is the second part of the data not being accounted to the
correct buffer log format structure? It took a little more work with
gdb to work out that the buffer log format structure was both
expecting it to be there but hadn't accounted for it. It was at that
point I went to the kernel code, as clearly this wasn't a bug in
xfs_logprint and the kernel was writing bad stuff to the log.

First port of call was the buffer item formatting code, and the
discontiguous memory/contiguous dirty region handling code
immediately stood out. I've wondered for a long time why the code
had this comment in it:

                        vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
                        vecp->i_len = nbits * XFS_BLF_CHUNK;
                        vecp->i_type = XLOG_REG_TYPE_BCHUNK;
/*
 * You would think we need to bump the nvecs here too, but we do not
 * this number is used by recovery, and it gets confused by the boundary
 * split here
 *                      nvecs++;
 */
                        vecp++;

And it didn't account for the extra vector pointer. The case being
handled here is that a contiguous dirty region lies across a
boundary that cannot be memcpy()d across, and so has to be split
into two separate operations for xlog_write() to perform.

What this code assumes is that what is written to the log is two
consecutive blocks of data that are accounted in the buf log format
item as the same contiguous dirty region and so will get decoded as
such by the log recovery code.

The thing is, xlog_write() knows nothing about this, and so just
does it's normal thing of adding an opheader for each vector. That
means the 8k region gets written to the log as two separate regions
of 4k each, but because nvecs has not been incremented, the buf log
format item accounts for only one of them.

Hence when we come to log recovery, we process the first 4k region
and then expect to come across a new item that starts with a log
format structure of some kind that tells us whenteh next data is
going to be. Instead, we hit raw buffer data and things go bad real
quick.

So, the commit from 2002 that commented out nvecs++ is just plain
wrong. It breaks log recovery completely, and it would seem the only
reason this hasn't been since then is that we don't log large
contigous regions of multi-page unmapped buffers very often. Never
would be a closer estimate, at least until the CRC code came along....

So, lets fix that by restoring the nvecs accounting for the extra
region when we hit this case.....

.... and there's the problemin log recovery it is apparently working
around:

XFS: Assertion failed: i == item->ri_total, file: fs/xfs/xfs_log_recover.c, line: 2135

Yup, xlog_recover_do_reg_buffer() doesn't handle contigous dirty
regions being broken up into multiple regions by the log formatting
code. That's an easy fix, though - if the number of contiguous dirty
bits exceeds the length of the region being copied out of the log,
only account for the number of dirty bits that region covers, and
then loop again and copy more from the next region. It's a 2 line
fix.

Now xfstests xfs/085 passes, we have one less piece of mystery
code, and one more important piece of knowledge about how to
structure new log format items..
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When CRCs are enabled, the number of blocks needed to hold a remote
symlink on a 1k block size filesystem may be 2 instead of 1. The
transaction reservation for the allocated blocks was not taking this
into account and only allocating one block. Hence when trying to
read or invalidate such symlinks, we are mapping a hole where there
should be a block and things go bad at that point.

Fix the reservation to use the correct block count, clean up the
block count calculation similar to the remote attribute calculation,
and add a debug guard to detect when we don't write the entire
symlink to disk.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>