Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

All other xfs_buf_get/read-like helpers return the buffer locked, make sure
xfs_buf_get_uncached isn't different for no reason.  Half of the callers
already lock it directly after, and the others probably should also keep
it locked if only for consistency and beeing able to use xfs_buf_rele,
but I'll leave that for later.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Rename xfs_buf_cond_lock and reverse it's return value to fit most other
trylock operations in the Kernel and XFS (with the exception of down_trylock,
after which xfs_buf_cond_lock was modelled), and replace xfs_buf_lock_val
with an xfs_buf_islocked for use in asserts, or and opencoded variant in
tracing.  remove the XFS_BUF_* wrappers for all the locking helpers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Micro-optimize various comparisms by always byteswapping the constant
instead of the variable, which allows to do the swap at compile instead
of runtime.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

When we free a vmapped buffer, we need to ensure the vmap address
and length we free is the same as when it was allocated. In various
places in the log code we change the memory the buffer is pointing
to before issuing IO, but we never reset the buffer to point back to
it's original memory (or no memory, if that is the case for the
buffer).

As a result, when we free the buffer it points to memory that is
owned by something else and attempts to unmap and free it. Because
the range does not match any known mapped range, it can trigger
BUG_ON() traps in the vmap code, and potentially corrupt the vmap
area tracking.

Fix this by always resetting these buffers to their original state
before freeing them.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Convert the xfs log operations to use the new error logging
interfaces. This removes the xlog_{warn,panic} wrappers and makes
almost all errors emit the device they belong to instead of just
refering to "XFS".
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

We currently have a global error message buffer in cmn_err that is
protected by a spin lock that disables interrupts.  Recently there
have been reports of NMI timeouts occurring when the console is
being flooded by SCSI error reports due to cmn_err() getting stuck
trying to print to the console while holding this lock (i.e. with
interrupts disabled). The NMI watchdog is seeing this CPU as
non-responding and so is triggering a panic.  While the trigger for
the reported case is SCSI errors, pretty much anything that spams
the kernel log could cause this to occur.

Realistically the only reason that we have the intemediate message
buffer is to prepend the correct kernel log level prefix to the log
message. The only reason we have the lock is to protect the global
message buffer and the only reason the message buffer is global is
to keep it off the stack. Hence if we can avoid needing a global
message buffer we avoid needing the lock, and we can do this with a
small amount of cleanup and some preprocessor tricks:

	1. clean up xfs_cmn_err() panic mask functionality to avoid
	   needing debug code in xfs_cmn_err()
	2. remove the couple of "!" message prefixes that still exist that
	   the existing cmn_err() code steps over.
	3. redefine CE_* levels directly to KERN_*
	4. redefine cmn_err() and friends to use printk() directly
	   via variable argument length macros.

By doing this, we can completely remove the cmn_err() code and the
lock that is causing the problems, and rely solely on printk()
serialisation to ensure that we don't get garbled messages.

A series of followup patches is really needed to clean up all the
cmn_err() calls and related messages properly, but that results in a
series that is not easily back portable to enterprise kernels. Hence
this initial fix is only to address the direct problem in the lowest
impact way possible.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

log->l_tail_lsn is currently protected by the log grant lock. The
lock is only needed for serialising readers against writers, so we
don't really need the lock if we make the l_tail_lsn variable an
atomic. Converting the l_tail_lsn variable to an atomic64_t means we
can start to peel back the grant lock from various operations.

Also, provide functions to safely crack an atomic LSN variable into
it's component pieces and to recombined the components into an
atomic variable. Use them where appropriate.

This also removes the need for explicitly holding a spinlock to read
the l_tail_lsn on 32 bit platforms.
Signed-off-by: NDave Chinner <dchinner@redhat.com>

log->l_last_sync_lsn is updated in only one critical spot - log
buffer Io completion - and is protected by the grant lock here. This
requires the grant lock to be taken for every log buffer IO
completion. Converting the l_last_sync_lsn variable to an atomic64_t
means that we do not need to take the grant lock in log buffer IO
completion to update it.

This also removes the need for explicitly holding a spinlock to read
the l_last_sync_lsn on 32 bit platforms.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Prepare for switching the grant heads to atomic variables by
combining the two 32 bit values that make up the grant head into a
single 64 bit variable.  Provide wrapper functions to combine and
split the grant heads appropriately for calculations and use them as
necessary.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

We now have two copies of AIL insert operations that are mostly
duplicate functionality. The single log item updates can be
implemented via the bulk updates by turning xfs_trans_ail_update()
into a simple wrapper. This removes all the duplicate insert
functionality and associated helpers.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

EFI/EFD interactions are protected from races by the AIL lock. They
are the only type of log items that require the the AIL lock to
serialise internal state, so they need to be separated from the AIL
lock before we can do bulk insert operations on the AIL.

To acheive this, convert the counter of the number of extents in the
EFI to an atomic so it can be safely manipulated by EFD processing
without locks. Also, convert the EFI state flag manipulations to use
atomic bit operations so no locks are needed to record state
changes. Finally, use the state bits to determine when it is safe to
free the EFI and clean up the code to do this neatly.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Dispatch to a different helper for phase1 vs phase2 in
xlog_recover_commit_trans instead of doing it in all the
low-level functions.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Merge the call to xlog_recover_reorder_trans and the loop over the
recovery items from xlog_recover_do_trans into xlog_recover_commit_trans,
and keep the switch statement over the log item types as a separate helper.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

XFS used to support different types of buffer log items long time
ago.  Remove the switch statements checking the log item type in
various buffer recovery helpers that were left over from those days
and the rather useless xlog_recover_do_buffer_pass2 wrapper.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Stop having two different names for many buffer functions and use
the more descriptive xfs_buf_* names directly.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Each buffer contains both a buftarg pointer and a mount pointer. If
we add a mount pointer into the buftarg, we can avoid needing the
b_mount field in every buffer and grab it from the buftarg when
needed instead. This shrinks the xfs_buf by 8 bytes.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

xfs_buf_get_nodaddr() is really used to allocate a buffer that is
uncached. While it is not directly assigned a disk address, the fact
that they are not cached is a more important distinction. With the
upcoming uncached buffer read primitive, we should be consistent
with this disctinction.

While there, make page allocation in xfs_buf_get_nodaddr() safe
against memory reclaim re-entrancy into the filesystem by allowing
a flags parameter to be passed.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

By making this member a void pointer we can get rid of a lot of pointless
casts.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>

Dmapi support was never merged upstream, but we still have a lot of hooks
bloating XFS for it, all over the fast pathes of the filesystem.

This patch drops over 700 lines of dmapi overhead.  If we'll ever get HSM
support in mainline at least the namespace events can be done much saner
in the VFS instead of the individual filesystem, so it's not like this
is much help for future work.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

The block number comes from bulkstat based inode lookups to shortcut
the mapping calculations. We ar enot able to trust anything from
bulkstat, so drop the block number as well so that the correct
lookups and mappings are always done.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Add suggested cleanups to commit 29db3370a1369541d58d692fbfb168b8a0bd7f41
from review that didn't end up being commited.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Clean up the buffer log format (XFS_BLI_*) flags because they have a
polluted namespace. They XFS_BLI_ prefix is used for both in-memory
and on-disk flag feilds, but have overlapping values for different
flags. Rename the buffer log format flags to use the XFS_BLF_*
prefix to avoid confusing them with the in-memory XFS_BLI_* prefixed
flags.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

There remains only one user of the l_sectbb_mask field in the log
structure.  Just kill it off and compute the mask where needed from
the power-of-2 sector size.

(Only update from last post is to accomodate the changes in the
previous patch in the series.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Change struct log so it keeps track of the size (in basic blocks) of
a log sector in l_sectBBsize rather than the log-base-2 of that
value (previously, l_sectbb_log).  The name was chosen for
consistency with the other fields in the structure that represent
a number of basic blocks.

(Updated so that a variable used in computing and verifying a log's
sector size is named "log2_size".  Also added the "BB" to the
structure field name, based on feedback from Eric Sandeen.  Also
dropped some superfluous parentheses.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

This can't be enabled through the build system and has been dead for
ages.  Note that the CRC patches add back log checksumming, but the
code is quite different from the version removed here anyway.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>

Odds and ends in "xfs_log_recover.c".  This patch just contains some
minor things that didn't seem to warrant their own individual
patches:
- In xlog_bread_noalign(), drop an assertion that a pointer is
  non-null (the crash will tell us it was a bad pointer).
- Add a more descriptive header comment for xlog_find_verify_cycle().
- Make a few additions to the comments in xlog_find_head().  Also
  rearrange some expressions in a few spots to produce the same
  result, but in a way that seems more clear what's being computed.

(Updated in response to Dave's review comments.  Note I did not
split this patch like I said I would.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

In xlog_find_cycle_start() use a local variable for some repeated
operations rather than constantly accessing the memory location
whose address is passed in.

(This version drops an assertion that a pointer is non-null.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Rename a label used in xlog_find_head() that I thought was poorly
chosen.  Also combine two adjacent labels xlog_find_tail() into a
single label, and give it a more generic name.

(Now using Dave's suggested "validate_head" name for first label.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

There are a number of places where a log sector size of 1 uses
special case code.  The round_up() and round_down() macros
produce the correct result even when the log sector size is 1, and
this eliminates the need for treating this as a special case.
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Define a function that encapsulates checking the validity of a log
block count.

(Updated from previous version--no longer includes error reporting in the
encapsulated validation function.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>

XLOG_SECTOR_ROUNDUP_BBCOUNT() and XLOG_SECTOR_ROUNDDOWN_BLKNO()
are now fairly simple macro translations.  Just get rid of them in
favor of the round_up() and round_down() macro calls they represent.

Also, in spots in xlog_get_bp() and xlog_write_log_records(),
round_up() was being called with value 1, which just evaluates
to the macro's second argument; so just use that instead.
In the latter case, make use of that value, as long as it's
already been computed.
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <dchinner@redhat.com>

XLOG_SECTOR_ROUNDUP_BBCOUNT() is defined in "fs/xfs/xfs_log_recover.c"
in an overly-complicated way.  It is basically roundup(), but that
is not at all clear from its definition.  (Actually, there is
another macro round_up() that applies for power-of-two-based masks
which I'll be using here.)

The operands in XLOG_SECTOR_ROUNDUP_BBCOUNT() are basically the
block number (bbs) and the log sector basic block mask
(log->l_sectbb_mask).  I'll call them B and M for this discussion.

The macro computes is value this way:
	M && (B & M) ? (B + M + 1) & ~M : B

Put another way, we can break it into 3 cases:
	1)  ! M          -> B			# 0 mask, no effect
	2)  ! (B & M)    -> B			# sector aligned
	3)  M && (B & M) -> (B + M + 1) & ~M	# round up otherwise

The round_up() macro is cleverly defined using a value, v, and a
power-of-2, p, and the result is the nearest multiple of p greater
than or equal to v.  Its value is computed something like this:
	((v - 1) | (p - 1)) + 1
Let's consider using this in the context of the 3 cases above.

When p = 2^0 = 1, the result boils down to ((v - 1) | 0) + 1, so it
just translates any value v to itself.  That handles case (1) above.

When p = 2^n, n > 0, we know that (p - 1) will be a mask with all n
bits 0..n-1 set.  The condition in this case occurs when none of
those mask bits is set in the value v provided.  If that is the
case, subtracting 1 from v will have 1's in all those lower bits (at
least).  Therefore, OR-ing the mask with that decremented value has
no effect, so adding the 1 back again will just translate the v to
itself.  This handles case (2).

Otherwise, the value v is greater than some multiple of p, and
decrementing it will produce a result greater than or equal to that
multiple.  OR-ing in the mask will produce a value 1 less than the
next multiple of p, so finally adding 1 back will result in the
desired rounded-up value.  This handles case (3).

Hopefully this is convincing.

While I was at it, I converted XLOG_SECTOR_ROUNDDOWN_BLKNO() to use
the round_down() macro.
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <dchinner@redhat.com>

This fixes a bug in two places that I found by inspection.  In
xlog_find_verify_cycle() and xlog_write_log_records(), the code
attempts to allocate a buffer to hold as many blocks as possible.
It gives up if the number of blocks to be allocated gets too small.
Right now it uses log->l_sectbb_log as that lower bound, but I'm
sure it's supposed to be the actual log sector size instead.  That
is, the lower bound should be (1 << log->l_sectbb_log).

Also define a simple macro xlog_sectbb(log) to represent the number
of basic blocks in a sector for the given log.

(No change from original submission; I have implemented Christoph's
suggestion about storing l_sectsize rather than l_sectbb_log in
a new, separate patch in this series.)
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>

Currently there is no tracing in log recovery, so it is difficult to
determine what is going on when something goes wrong.

Add tracing for log item recovery to provide visibility into the log
recovery process. The tracing added shows regions being extracted
from the log transactions and added to the transaction hash forming
recovery items, followed by the reordering, cancelling and finally
recovery of the items.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Remove the XFS_LOG_FORCE argument which was always set, and the
XFS_LOG_URGE define, which was never used.

Split xfs_log_force into a two helpers - xfs_log_force which forces
the whole log, and xfs_log_force_lsn which forces up to the
specified LSN.  The underlying implementations already were entirely
separate, as were the users.

Also re-indent the new _xfs_log_force/_xfs_log_force which
previously had a weird coding style.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Currently we define aliases for the buffer flags in various
namespaces, which only adds confusion.  Remove all but the XBF_
flags to clean this up a bit.

Note that we still abuse XFS_B_ASYNC/XBF_ASYNC for some non-buffer
uses, but I'll clean that up later.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>