xfs: allow setting full range of panic tags

xfs will not allow combining other panic masks with
XFS_PTAG_VERIFIER_ERROR.

# sysctl fs.xfs.panic_mask=511
sysctl: setting key "fs.xfs.panic_mask": Invalid argument
fs.xfs.panic_mask = 511

Update to the maximum value that can be set to allow the full range of
masks. Do this using a mask of possible values to prevent this happening
again as suggested by Darrick.

Fixes: d519da41e2b7 ("xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask")
Signed-off-by: Donald Douwsma <ddouwsma@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: add debug knob to slow down writeback for fun

Add a new error injection knob so that we can arbitrarily slow down
writeback to test for race conditions and aberrant reclaim behavior if
the writeback mechanisms are slow to issue writeback. This will enable
functional testing for the ifork sequence counters introduced in commit
745b3f76d1c8 ("xfs: maintain a sequence count for inode fork
manipulations").

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: convert ptag flags to unsigned.

5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: add trace point for fs shutdown

Add a tracepoint for fs shutdowns so we can capture that in ftrace
output.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: xfs_buf_corruption_error should take __this_address

Add a xfs_failaddr_t parameter to this function so that callers can
potentially pass in (and therefore report) the exact point in the code
where we decided that a metadata buffer was corrupt. This enables us to
wire it up to checking functions that have to run outside of verifiers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: kill the XFS_WANT_CORRUPT_* macros

The XFS_WANT_CORRUPT_* macros conceal subtle side effects such as the
creation of local variables and redirections of the code flow. This is
pretty ugly, so replace them with explicit XFS_IS_CORRUPT tests that
remove both of those ugly points. The change was performed with the
following coccinelle script:

@@
expression mp, test;
identifier label;
@@

- XFS_WANT_CORRUPTED_GOTO(mp, test, label);
+ if (XFS_IS_CORRUPT(mp, !test)) { error = -EFSCORRUPTED; goto label; }

@@
expression mp, test;
@@

- XFS_WANT_CORRUPTED_RETURN(mp, test);
+ if (XFS_IS_CORRUPT(mp, !test)) return -EFSCORRUPTED;

@@
expression mp, lval, rval;
@@

- XFS_IS_CORRUPT(mp, !(lval == rval))
+ XFS_IS_CORRUPT(mp, lval != rval)

@@
expression mp, e1, e2;
@@

- XFS_IS_CORRUPT(mp, !(e1 && e2))
+ XFS_IS_CORRUPT(mp, !e1 || !e2)

@@
expression e1, e2;
@@

- !(e1 == e2)
+ e1 != e2

@@
expression e1, e2, e3, e4, e5, e6;
@@

- !(e1 == e2 && e3 == e4) || e5 != e6
+ e1 != e2 || e3 != e4 || e5 != e6

@@
expression e1, e2, e3, e4, e5, e6;
@@

- !(e1 == e2 || (e3 <= e4 && e5 <= e6))
+ e1 != e2 && (e3 > e4 || e5 > e6)

@@
expression mp, e1, e2;
@@

- XFS_IS_CORRUPT(mp, !(e1 <= e2))
+ XFS_IS_CORRUPT(mp, e1 > e2)

@@
expression mp, e1, e2;
@@

- XFS_IS_CORRUPT(mp, !(e1 < e2))
+ XFS_IS_CORRUPT(mp, e1 >= e2)

@@
expression mp, e1;
@@

- XFS_IS_CORRUPT(mp, !!e1)
+ XFS_IS_CORRUPT(mp, e1)

@@
expression mp, e1, e2;
@@

- XFS_IS_CORRUPT(mp, !(e1 || e2))
+ XFS_IS_CORRUPT(mp, !e1 && !e2)

@@
expression mp, e1, e2, e3, e4;
@@

- XFS_IS_CORRUPT(mp, !(e1 == e2) && !(e3 == e4))
+ XFS_IS_CORRUPT(mp, e1 != e2 && e3 != e4)

@@
expression mp, e1, e2, e3, e4;
@@

- XFS_IS_CORRUPT(mp, !(e1 <= e2) || !(e3 >= e4))
+ XFS_IS_CORRUPT(mp, e1 > e2 || e3 < e4)

@@
expression mp, e1, e2, e3, e4;
@@

- XFS_IS_CORRUPT(mp, !(e1 == e2) && !(e3 <= e4))
+ XFS_IS_CORRUPT(mp, e1 != e2 && e3 > e4)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: always log corruption errors

Make sure we log something to dmesg whenever we return -EFSCORRUPTED up
the call stack.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: constify the buffer pointer arguments to error functions

Some of the xfs error message functions take a pointer to a buffer that
will be dumped to the system log. The logging functions don't change
the contents, so constify all the parameters. This enables the next
patch to ensure that we log bad metadata when we encounter it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask

Currently we have a few PTAGs in place allowing us to transform a filesystem
error in a BUG() call. However, we don't have a panic tag for corrupt
metadata, so introduce XFS_PTAG_VERIFIER_ERROR so that the administrator can
use the fs.xfs.panic_mask sysctl knob to convert any error detected by buffer
verifiers into a kernel panic.

Signed-off-by: Marco Benatto <mbenatto@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
[darrick: light editing of commit message]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}

/^ \* This program is free software/ {
hdr = 2.0;
next
}

/any later version./ {
tag = "GPL-2.0+"
next
}

/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}

/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}

/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}

// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}

END { }
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: explicitly pass buffer size to xfs_corruption_error

Explicitly pass the buffer length to xfs_corruption_error() instead of
assuming XFS_CORRUPTION_DUMP_LEN so that we avoid dumping off the end
of the buffer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: refactor inode buffer verifier error logging

When the inode buffer verifier encounters an error, it's much more
helpful to print a buffer from the offending inode instead of just the
start of the inode chunk buffer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: refactor inode verifier corruption error printing

Refactor inode verifier error reporting into a non-libxfs function so
that we aren't encoding the message format in libxfs. This also
changes the kernel dmesg output to resemble buffer verifier errors
more closely.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: dump the first 128 bytes of any corrupt buffer

Increase the corrupt buffer dump to the first 128 bytes since v5
filesystems have larger block headers than before.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: teach error reporting functions to take xfs_failaddr_t

Convert the two other error reporting functions to take xfs_failaddr_t
when the caller wishes to capture a code pointer instead of the classic
void * pointer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: refactor verifier callers to print address of failing check

Refactor the callers of verifiers to print the instruction address of a
failing check.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: refactor xfs_verifier_error and xfs_buf_ioerror

Since all verification errors also mark the buffer as having an error,
we can combine these two calls. Later we'll add a xfs_failaddr_t
parameter to promote the idea of reporting corruption errors and the
address of the failing check to enable better debugging reports.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: move error injection tags into their own file

Move the error injection tag names into a libxfs header so that we can
share it between kernel and userspace.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: buffer lru reference count error injection tag

XFS uses a fixed reference count for certain types of buffers in the
internal LRU cache. These reference counts dictate how aggressively
certain buffers are reclaimed vs. others. While the reference counts
implements priority across different buffer types, all buffers
(other than uncached buffers) are typically cached for at least one
reclaim cycle.

We've had at least one bug recently that has been hidden by a
released buffer sitting around in the LRU. Users hitting the problem
were able to reproduce under enough memory pressure to cause
aggressive reclaim in a particular window of time.

To support future xfstests cases, add an error injection tag to
hardcode the buffer reference count to zero. When enabled, this
bypasses caching of associated buffers and facilitates test cases
that depend on this behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: add log item pinning error injection tag

Add an error injection tag to force log items in the AIL to the
pinned state. This option can be used by test infrastructure to
induce head behind tail conditions. Specifically, this is intended
to be used by xfstests to reproduce log recovery problems after
failed/corrupted log writes overwrite the last good tail LSN in the
log.

When enabled, AIL push attempts see log items in the AIL in the
pinned state. This stalls metadata writeback and thus prevents the
current tail of the log from moving forward. When disabled,
subsequent AIL pushes observe the log items in their appropriate
state and filesystem operation continues as normal.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: replace log_badcrc_factor knob with error injection tag

Now that error injection tags support dynamic frequency adjustment,
replace the debug mode sysfs knob that controls log record CRC error
injection with an error injection tag.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: convert drop_writes to use the errortag mechanism

We now have enhanced error injection that can control the frequency
with which errors happen, so convert drop_writes to use this.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

xfs: remove unneeded parameter from XFS_TEST_ERROR

Since we moved the injected error frequency controls to the mountpoint,
we can get rid of the last argument to XFS_TEST_ERROR.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

xfs: expose errortag knobs via sysfs

Creates a /sys/fs/xfs/$dev/errortag/ directory to control the errortag
values directly. This enables us to control the randomness values,
rather than having to accept the defaults.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

xfs: make errortag a per-mountpoint structure

Remove the xfs_etest structure in favor of a per-mountpoint structure.
This will give us the flexibility to set as many error injection points
as we want, and later enable us to set up sysfs knobs to set the trigger
frequency as we wish. This comes at a cost of higher memory use, but
unti we hit 1024 injection points (we're at 29) or a lot of mounts this
shouldn't be a huge issue.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

xfs: simulate per-AG reservations being critically low

Create an error injection point that enables us to simulate being
critically low on per-AG block reservations. This should enable us to
simulate this specific ENOSPC condition so that we can test falling back
to a regular file copy.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: implement deferred bmbt map/unmap operations

Implement deferred versions of the inode block map/unmap functions.
These will be used in subsequent patches to make reflink operations
atomic.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: connect refcount adjust functions to upper layers

Plumb in the upper level interface to schedule and finish deferred
refcount operations via the deferred ops mechanism.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: adjust refcount of an extent of blocks in refcount btree

Provide functions to adjust the reference counts for an extent of
physical blocks stored in the refcount btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

xfs: propagate bmap updates to rmapbt

When we map, unmap, or convert an extent in a file's data or attr
fork, schedule a respective update in the rmapbt. Previous versions
of this patch required a 1:1 correspondence between bmap and rmap,
but this is no longer true as we now have ability to make interval
queries against the rmapbt.

We use the deferred operations code to handle redo operations
atomically and deadlock free. This plumbs in all five rmap actions
(map, unmap, convert extent, alloc, free); we'll use the first three
now for file data, and reflink will want the last two. We also add
an error injection site to test log recovery.

Finally, we need to fix the bmap shift extent code to adjust the
rmaps correctly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: add tracepoints and error injection for deferred extent freeing

Add a couple of tracepoints for the deferred extent free operation and
a site for injecting errors while finishing the operation. This makes
it easier to debug deferred ops and test log redo.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: don't allow negative error tags

Errors go from zero which means no error to XFS_ERRTAG_MAX (22). My
static checker complains that xfs_errortag_add() puts an upper bound on
this but not a lower bound. Let's fix it by making it unsigned.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: remove inst_t

We can simply use a void pointer to pass a long return addresses in the
debugging helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: pass mp to XFS_WANT_CORRUPTED_RETURN

Today, if we hit an XFS_WANT_CORRUPTED_RETURN we don't print any
information about which filesystem hit it. Passing in the mp allows
us to print the filesystem (device) name, which is a pretty critical
piece of information.

Tested by running fsfuzzer 'til I hit some.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: pass mp to XFS_WANT_CORRUPTED_GOTO

Today, if we hit an XFS_WANT_CORRUPTED_GOTO we don't print any
information about which filesystem hit it. Passing in the mp allows
us to print the filesystem (device) name, which is a pretty critical
piece of information.

Tested by running fsfuzzer 'til I hit some.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: global error sign conversion

Convert all the errors the core XFs code to negative error signs
like the rest of the kernel and remove all the sign conversion we
do in the interface layers.

Errors for conversion (and comparison) found via searches like:

$ git grep " E" fs/xfs
$ git grep "return E" fs/xfs
$ git grep " E[A-Z].*;$" fs/xfs

Negation points found via searches like:

$ git grep "= -[a-z,A-Z]" fs/xfs
$ git grep "return -[a-z,A-D,F-Z]" fs/xfs
$ git grep " -[a-z].*;" fs/xfs

[ with some bits I missed from Brian Foster ]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: Nuke XFS_ERROR macro

XFS_ERROR was designed long ago to trap return values, but it's not
runtime configurable, it's not consistently used, and we can do
similar error trapping with ftrace scripts and triggers from
userspace.

Just nuke XFS_ERROR and associated bits.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: add xfs_verifier_error()

We want to distinguish between corruption, CRC errors,
etc. In addition, the full stack trace on verifier errors
seems less than helpful; it looks more like an oops than
corruption.

Create a new function to specifically alert the user to
verifier errors, which can differentiate between
EFSCORRUPTED and CRC mismatches. It doesn't dump stack
unless the xfs error level is turned up high.

Define a new error message (EFSBADCRC) to clearly identify
CRC errors. (Defined to EBADMSG, bad message)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: kill support/debug.[ch]

The remaining functionality in debug.[ch] is effectively just assert
handling, conditional debug definitions and hex dumping. The hex
dumping and assert function can be moved into the new printk module,
while the rest can be moved into top-level header files. This allows
fs/xfs/support/debug.[ch] to be completely removed from the
codebase.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: kill xfs_fs_mount_cmn_err() macro

The xfs_fs_mount_cmn_err() hides a simple check as to whether the
mount path should output an error or not. Remove the macro and open
code the check.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: kill xfs_fs_repair_cmn_err() macro

In certain cases of inode corruption, the xfs_fs_repair_cmn_err()
macro is used to output an extra message in the corruption report.
That extra message is "unmount and run xfs_repair", which really
applies to any corruption report. Each case that this macro is
called (except one) a following call to xfs_corruption_error() is
made to optionally dump more information about the error.

Hence, move the output of "run xfs_repair" to xfs_corruption_error()
so that it is output on all corruption reports. Also, convert the
callers of the repair macro that don't call xfs_corruption_error()
to call it, hence provide consiѕtent error reporting for all cases
where xfs_fs_repair_cmn_err() used to be called.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: convert xfs_cmn_err to xfs_alert_tag

Continue the conversion of the old cmn_err interface be converting
all the conditional panic tag errors to xfs_alert_tag() and then
removing xfs_cmn_err().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: prevent NMI timeouts in cmn_err

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: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

xfs: only run xfs_error_test if error injection is active

Recent tests writing lots of small files showed the flusher thread
being CPU bound and taking a long time to do allocations on a debug
kernel. perf showed this as the prime reason:

samples pcnt function DSO
_______ _____ ___________________________ _________________

224648.00 36.8% xfs_error_test [kernel.kallsyms]
86045.00 14.1% xfs_btree_check_sblock [kernel.kallsyms]
39778.00 6.5% prandom32 [kernel.kallsyms]
37436.00 6.1% xfs_btree_increment [kernel.kallsyms]
29278.00 4.8% xfs_btree_get_rec [kernel.kallsyms]
27717.00 4.5% random32 [kernel.kallsyms]

Walking btree blocks during allocation checking them requires each
block (a cache hit, so no I/O) call xfs_error_test(), which then
does a random32() call as the first operation. IOWs, ~50% of the
CPU is being consumed just testing whether we need to inject an
error, even though error injection is not active.

Kill this overhead when error injection is not active by adding a
global counter of active error traps and only calling into
xfs_error_test when fault injection is active.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: add const qualifiers to xfs error function args

Change the tag and file name arguments to xfs_error_report() and
xfs_corruption_error() to use a const qualifier.

Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>

[XFS] avoid memory allocations in xfs_fs_vcmn_err

xfs_fs_vcmn_err can be called under a spinlock, but does a sleeping memory
allocation to create buffer for it's internal sprintf. Fortunately it's
the only caller of icmn_err, so we can merge the two and have one single
static buffer and spinlock protecting it. While we're at it make sure
we proper __attribute__ format annotations so that the compiler can detect
mismatched format strings.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

[XFS] kill INDUCE_IO_ERROR

All the error injection is already enabled through ifdef DEBUG, so kill
the never set second cpp symbol to activate it without the rest of the
debugging infrastructure.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31771a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

[XFS] streamline init/exit path

Currently the xfs module init/exit code is a mess. It's farmed out over a
lot of function with very little error checking. This patch makes sure we
propagate all initialization failures properly and clean up after them.
Various runtime initializations are replaced with compile-time
initializations where possible to make this easier. The exit path is
similarly consolidated.

There's now split out function to create/destroy the kmem zones and
alloc/free the trace buffers. I've also changed the ktrace allocations to
KM_MAYFAIL and handled errors resulting from that.

And yes, we really should replace the XFS_*_TRACE ifdefs with a single
XFS_TRACE..

SGI-PV: 976035

SGI-Modid: xfs-linux-melb:xfs-kern:31354a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

[XFS] lose xfs_hex_dump in favor of print_hex_dump

No need for xfs to have its own hex dumping routine now that the kernel
has one.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:29847a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

[XFS] kill the vfs_fsid and vfs_altfsid members in struct bhv_vfs

vfs_altfsid was just a pointer to mp->m_fixedfsid so we can trivially
replace it with the latter. vfs_fsid also was identical to m_fixedfsid
through rather obfuscated ways so we can kill it as well and simply its
only user.

SGI-PV: 969608
SGI-Modid: xfs-linux-melb:xfs-kern:29506a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

[XFS] Remove a bunch of unused functions from XFS.

Patch provided by Eric Sandeen (sandeen@sandeen.net).

SGI-PV: 960897
SGI-Modid: xfs-linux-melb:xfs-kern:28038a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

[XFS] Make quiet mounts quiet

The XFS quiet mount logic was inverted making quiet mounts noisy and vice
versa. Fix it.

SGI-PV: 958469
SGI-Modid: xfs-linux-melb:xfs-kern:27520a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Tim Shimmin <tes@sgi.com>

[XFS] Improve error handling for the zero-fsblock extent detection code.

SGI-PV: 955302
SGI-Modid: xfs-linux-melb:xfs-kern:26802a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

[XFS] Remove several macros that are no longer used anywhere

SGI-PV: 955302
SGI-Modid: xfs-linux-melb:xfs-kern:26749a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

[XFS] Implement the silent parameter to fill_super, previously ignored.

SGI-PV: 951299
SGI-Modid: xfs-linux-melb:xfs-kern:25632a

Signed-off-by: Nathan Scott <nathans@sgi.com>

[XFS] Merge in trivial changes, sync up headers with userspace
equivalents.

SGI-PV: 907752
SGI-Modid: xfs-linux-melb:xfs-kern:24961a

Signed-off-by: Nathan Scott <nathans@sgi.com>

[XFS] Update license/copyright notices to match the prefered SGI
boilerplate.

SGI-PV: 913862
SGI-Modid: xfs-linux:xfs-kern:23903a

Signed-off-by: Nathan Scott <nathans@sgi.com>

[XFS] Remove xfs_macros.c, xfs_macros.h, rework headers a whole lot.

SGI-PV: 943122
SGI-Modid: xfs-linux:xfs-kern:23901a

Signed-off-by: Nathan Scott <nathans@sgi.com>

[XFS] mark various symbols static Patch from Adrian Bunk

SGI-PV: 936255
SGI-Modid: xfs-linux:xfs-kern:192760a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!