Add project quota changes to all the places where group quota field
is used:
   * add separate project quota members into various structures
   * split project quota and group quotas so that instead of overriding
     the group quota members incore, the new project quota members are
     used instead
   * get rid of usage of the OQUOTA flag incore, in favor of separate
     group and project quota flags.
   * add a project dquot argument to various functions.

Not using the pquotino field from superblock yet.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

XFS removes sgid bits of subdirectories under a directory containing a default
acl.

When a default acl is set, it implies xfs to call xfs_setattr_nonsize() in its
code path. Such function is shared among mkdir and chmod system calls, and
does some checks unneeded by mkdir (calling inode_change_ok()). Such checks
remove sgid bit from the inode after it has been granted.

With this patch, we extend the meaning of XFS_ATTR_NOACL flag to avoid these
checks when acls are being inherited (thanks hch).

Also, xfs_setattr_mode, doesn't need to re-check for group id and capabilities
permissions, this only implies in another try to remove sgid bit from the
directories. Such check is already done either on inode_change_ok() or
xfs_setattr_nonsize().

Changelog:

V2: Extends the meaning of XFS_ATTR_NOACL instead of wrap the tests into another
    function

V3: Remove S_ISDIR check in xfs_setattr_nonsize() from the patch
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

During review of the separate project quota inode patches, it became
obvious that the dquot log reservation calculation underestimated
the number dquots that can be modified in a transaction. This has
it's roots way back in the Irix quota implementation.

That is, when quotas were first implemented in XFS, it only
supported user and project quotas as Irix did not have group quotas.
Hence the worst case operation involving dquot modification was
calculated to involve 2 user dquots and 1 project dquot or 1 user
dequot and 2 project dquots. i.e. 3 dquots. This was determined back
in 1996, and has remained unchanged ever since.

However, back in 2001, the Linux XFS port dropped all support for
project quota and implmented group quotas over the top. This was
effectively done with a search-and-replace of project with group,
and as such the log reservation was not changed. However, with the
advent of group quotas, chmod and rename now could modify more than
3 dquots in a single transaction - both could modify 4 dquots. Hence
this log reservation has been wrong for a long time.

In 2005, project quota support was reintroduced into Linux, but it
was implemented to be mutually exclusive to group quotas and so this
didn't add any new changes to the dquot log reservation. Hence when
project quotas were in use (rather than group quotas) the log
reservation was again valid, just like in the Irix days.

Now, with the addition of the separate project quota inode, group
and project quotas are no longer mutually exclusive, and hence
operations can now modify three dquots per inode where previously it
was only two. The worst case here is the rename transaction, which
can allocate/free space on two different directory inodes, and if
they have different uid/gid/prid configurations and are world
writeable, then rename can actually modify 6 different dquots now.

Further, the dquot log reservation doesn't take into account the
space used by the dquot log format structure that precedes the dquot
that is logged, and hence further underestimates the worst case
log space required by dquots during a transaction. This has been
missing since the first commit in 1996.

Hence the worst case log reservation needs to be increased from 3 to
6, and it needs to take into account a log format header for each of
those dquots.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

The conversion from local format to extent format requires
interpretation of the data in the fork being converted, so it cannot
be done in a generic way. It is up to the caller to convert the fork
format to extent format before calling into xfs_bmapi_write() so
format conversion can be done correctly.

The code in xfs_bmapi_write() to convert the format is used
implicitly by the attribute and directory code, but they
specifically zero the fork size so that the conversion does not do
any allocation or manipulation. Move this conversion into the
shortform to leaf functions for the dir/attr code so the conversions
are explicitly controlled by all callers.

Now we can remove the conversion code in xfs_bmapi_write.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

Because it's horribly out of date.

And mark various deprecated options as deprecated and give them a
removal date.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

Macro get_unused_fd() is used to allocate a file descriptor with
default flags. Those default flags (0) can be "unsafe":
O_CLOEXEC must be used by default to not leak file descriptor
across exec().

Instead of macro get_unused_fd(), functions anon_inode_getfd()
or get_unused_fd_flags() should be used with flags given by userspace.
If not possible, flags should be set to O_CLOEXEC to provide userspace
with a default safe behavor.

In a further patch, get_unused_fd() will be removed so that
new code start using anon_inode_getfd() or get_unused_fd_flags()
with correct flags.

This patch replaces calls to get_unused_fd() with equivalent call to
get_unused_fd_flags(0) to preserve current behavor for existing code.

The hard coded flag value (0) should be reviewed on a per-subsystem basis,
and, if possible, set to O_CLOEXEC.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

There are some unused codes at xfs_bulkstat():

- Variable bp is defined to point to the on-disk inode cluster
  buffer, but it proved to be of no practical help.

- We process the chunks of good inodes which were fetched by iterating
  btree records from an AG.  When processing inodes from each chunk,
  the code recomputing agbno if run into the first inode of a cluster,
  however, the agbno is not being used thereafter.

This patch tries to clean up those things.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

XFS_BROOT_SIZE_ADJ is an undocumented macro which accounts for
the difference in size between the on-disk and in-core btree
root.  It's much clearer to just use the newly-added
XFS_BMAP_BMDR_SPACE macro which gives us the on-disk size
directly.

In one case, we must test that the if_broot exists before
applying the macro, however.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

Remove all incore use of XFS_OQUOTA_ENFD and XFS_OQUOTA_CHKD. Instead,
start using XFS_GQUOTA_.* XFS_PQUOTA_.* counterparts for GQUOTA and
PQUOTA respectively.

On-disk copy still uses XFS_OQUOTA_ENFD and XFS_OQUOTA_CHKD.

Read and write of the superblock does the conversion from *OQUOTA*
to *[PG]QUOTA*.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

In preparation for combined pquota/gquota support, for the sake
of readability, change xfs_dquot_acct to be a 2-dimensional array.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

In preparation for combined pquota/gquota support, for the sake
of readability, do some code cleanup surrounding the affected
code.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

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

In preparation for combined pquota/gquota support, for the sake
of readability, change the macro to an inline function.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Ben 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: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

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

This patch clean out the left function variable as it is
useless to xfs_ialloc_get_rec().
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben 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: Gabriel VLASIU <gabriel@vlasiu.net>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben 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: Jie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben 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: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

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

This typedef is unnecessary and should just be removed.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben 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: Michael L. Semon <mlsemon35@gmail.com>
Debugged-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>