Commit graph

312 commits

Author SHA1 Message Date
Darrick J. Wong 722e251770 xfs: remove the extents array from the rmap update done log item
Nothing ever uses the extent array in the rmap update done redo
item, so remove it before it is fixed in the on-disk log format.

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>
2016-08-03 12:28:43 +10:00
Darrick J. Wong a650e8f98e xfs: add rmap btree block detection to log recovery
Originally-From: Dave Chinner <dchinner@redhat.com>

So such blocks can be correctly identified and have their operations
structures attached to validate recovery has not resulted in a
correct block.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03 12:17:11 +10:00
Darrick J. Wong 9e88b5d867 xfs: log rmap intent items
Provide a mechanism for higher levels to create RUI/RUD items, submit
them to the log, and a stub function to deal with recovered RUI items.
These parts will be connected to the rmapbt in a later patch.

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>
2016-08-03 12:09:48 +10:00
Darrick J. Wong 525488520a xfs: rmap btree requires more reserved free space
Originally-From: Dave Chinner <dchinner@redhat.com>

The rmap btree is allocated from the AGFL, which means we have to
ensure ENOSPC is reported to userspace before we run out of free
space in each AG. The last allocation in an AG can cause a full
height rmap btree split, and that means we have to reserve at least
this many blocks *in each AG* to be placed on the AGFL at ENOSPC.
Update the various space calculation functions to handle this.

Also, because the macros are now executing conditional code and are
called quite frequently, convert them to functions that initialise
variables in the struct xfs_mount, use the new variables everywhere
and document the calculations better.

[darrick.wong@oracle.com: don't reserve blocks if !rmap]
[dchinner@redhat.com: update m_ag_max_usable after growfs]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
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>
2016-08-03 11:38:24 +10:00
Darrick J. Wong dc42375d5f xfs: refactor redo intent item processing
Refactor the EFI intent item recovery (and cancellation) functions
into a general function that scans the AIL and an intent item type
specific handler.  Move the function that recovers a single EFI item
into the extent free item code.  We'll want the generalized function
when we start wiring up more redo item types.

Furthermore, ensure that log recovery only replays the redo items
that were in the AIL prior to recovery by checking the item LSN
against the largest LSN seen during log scanning.  As written this
should never happen, but we can be defensive anyway.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03 11:23:49 +10:00
Darrick J. Wong 3ab78df2a5 xfs: rework xfs_bmap_free callers to use xfs_defer_ops
Restructure everything that used xfs_bmap_free to use xfs_defer_ops
instead.  For now we'll just remove the old symbols and play some
cpp magic to make it work; in the next patch we'll actually rename
everything.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03 11:15:38 +10:00
Dave Chinner 2a4ad5894c Merge branch 'xfs-4.7-misc-fixes' into for-next 2016-05-20 10:33:17 +10:00
Christoph Hellwig 664b60f6ba xfs: improve kmem_realloc
Use krealloc to implement our realloc function.  This helps to avoid
new allocations if we are still in the slab bucket.  At least for the
bmap btree root that's actually the common case.

This also allows removing the now unused oldsize argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-04-06 09:47:01 +10:00
Christoph Hellwig 253f4911f2 xfs: better xfs_trans_alloc interface
Merge xfs_trans_reserve and xfs_trans_alloc into a single function call
that returns a transaction with all the required log and block reservations,
and which allows passing transaction flags directly to avoid the cumbersome
_xfs_trans_alloc interface.

While we're at it we also get rid of the transaction type argument that has
been superflous since we stopped supporting the non-CIL logging mode.  The
guts of it will be removed in another patch.

[dchinner: fixed transaction leak in error path in xfs_setattr_nonsize]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-04-06 09:19:55 +10:00
Dave Chinner ab9d1e4f7b Merge branch 'xfs-misc-fixes-4.6-3' into for-next 2016-03-09 08:18:30 +11:00
Dave Chinner 7f0ed5461a Merge branch 'xfs-buf-macro-cleanup-4.6' into for-next 2016-03-07 09:31:00 +11:00
Dave Chinner a2bbcb60ff Merge branch 'xfs-gut-icdinode-4.6' into for-next 2016-03-07 09:30:32 +11:00
Dave Chinner c53473be45 Merge branch 'xfs-rt-fixes-4.6' into for-next 2016-03-07 09:29:04 +11:00
Dave Chinner 9deed09554 Merge branch 'xfs-torn-log-fixes-4.5' into for-next 2016-03-07 09:28:36 +11:00
Dave Chinner a798011c8f xfs: reinitialise per-AG structures if geometry changes during recovery
If a crash occurs immediately after a filesystem grow operation, the
updated superblock geometry is found only in the log. After we
recover the log, the superblock is reread and re-initialised and so
has the new geometry in memory. If the new geometry has more AGs
than prior to the grow operation, then the new AGs will not have
in-memory xfs_perag structurea associated with them.

This will result in an oops when the first metadata buffer from a
new AG is looked up in the buffer cache, as the block lies within
the new geometry but then fails to find a perag structure on lookup.
This is easily fixed by simply re-initialising the perag structure
after re-reading the superblock at the conclusion of the first pahse
of log recovery.

This, however, does not fix the case of log recovery requiring
access to metadata in the newly grown space. Fortunately for us,
because the in-core superblock has not been updated, this will
result in detection of access beyond the end of the filesystem
and so recovery will fail at that point. If this proves to be
a problem, then we can address it separately to the current
reported issue.

Reported-by: Alex Lyakas <alex@zadarastorage.com>
Tested-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
2016-03-07 08:39:36 +11:00
Brian Foster 7f6aff3a29 xfs: only run torn log write detection on dirty logs
XFS uses CRC verification over a sub-range of the head of the log to
detect and handle torn writes. This torn log write detection currently
runs unconditionally at mount time, regardless of whether the log is
dirty or clean. This is problematic in cases where a filesystem might
end up being moved across different, incompatible (i.e., opposite
byte-endianness) architectures.

The problem lies in the fact that log data is not necessarily written in
an architecture independent format. For example, certain bits of data
are written in native endian format. Further, the size of certain log
data structures differs (i.e., struct xlog_rec_header) depending on the
word size of the cpu. This leads to false positive crc verification
errors and ultimately failed mounts when a cleanly unmounted filesystem
is mounted on a system with an incompatible architecture from data that
was written near the head of the log.

Update the log head/tail discovery code to run torn write detection only
when the log is not clean. This means something other than an unmount
record resides at the head of the log and log recovery is imminent. It
is a requirement to run log recovery on the same type of host that had
written the content of the dirty log and therefore CRC failures are
legitimate corruptions in that scenario.

Reported-by: Jan Beulich <JBeulich@suse.com>
Tested-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-07 08:22:22 +11:00
Brian Foster 717bc0ebca xfs: refactor in-core log state update to helper
Once the record at the head of the log is identified and verified, the
in-core log state is updated based on the record. This includes
information such as the current head block and cycle, the start block of
the last record written to the log, the tail lsn, etc.

Once torn write detection is conditional, this logic will need to be
reused. Factor the code to update the in-core log data structures into a
new helper function. This patch does not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-07 08:22:22 +11:00
Brian Foster 65b99a08b3 xfs: refactor unmount record detection into helper
Once the mount sequence has identified the head and tail blocks of the
physical log, the record at the head of the log is located and examined
for an unmount record to determine if the log is clean. This currently
occurs after torn write verification of the head region of the log.

This must ultimately be separated from torn write verification and may
need to be called again if the log head is walked back due to a torn
write (to determine whether the new head record is an unmount record).
Separate this logic into a new helper function. This patch does not
change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-07 08:22:22 +11:00
Brian Foster 82ff6cc26e xfs: separate log head record discovery from verification
The code that locates the log record at the head of the log is buried in
the log head verification function. This is fine when torn write
verification occurs unconditionally, but this behavior is problematic
for filesystems that might be moved across systems with different
architectures.

In preparation for separating examination of the log head for unmount
records from torn write detection, lift the record location logic out of
the log verification function and into the caller. This patch does not
change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-07 08:22:22 +11:00
Dave Chinner 12877da584 xfs: remove XFS_BUF_ZEROFLAGS macro
The places where we use this macro already clear unnecessary IO
flags (e.g. through xfs_bwrite()) or never have unexpected IO flags
set on them in the first place (e.g. iclog buffers). Remove the
macro from these locations, and where necessary clear only the
specific flags that are conditional in the current buffer context.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-10 15:01:30 +11:00
Dave Chinner b68c08219a xfs: remove XBF_WRITE flag wrapper macros
They only set/clear/check a flag, no need for obfuscating this
with a macro.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-10 15:01:11 +11:00
Dave Chinner 0cac682ff6 xfs: remove XBF_READ flag wrapper macros
They only set/clear/check a flag, no need for obfuscating this
with a macro.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-10 15:01:11 +11:00
Dave Chinner 1157b32c73 xfs: remove XBF_ASYNC flag wrapper macros
They only set/clear/check a flag, no need for obfuscating this
with a macro.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-10 15:01:11 +11:00
Dave Chinner b0388bf108 xfs: remove XBF_DONE flag wrapper macros
They only set/clear/check a flag, no need for obfuscating this
with a macro.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-10 15:01:11 +11:00
Dave Chinner c19b3b05ae xfs: mode di_mode to vfs inode
Move the di_mode value from the xfs_icdinode to the VFS inode, reducing
the xfs_icdinode byte another 2 bytes and collapsing another 2 byte hole
in the structure.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:54:58 +11:00
Dave Chinner 54d7b5c1d0 xfs: use vfs inode nlink field everywhere
The VFS tracks the inode nlink just like the xfs_icdinode. We can
remove the variable from the icdinode and use the VFS inode variable
everywhere, reducing the size of the xfs_icdinode by a further 4
bytes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:54:58 +11:00
Dave Chinner 3987848c7c xfs: remove timestamps from incore inode
The struct xfs_inode has two copies of the current timestamps in it,
one in the vfs inode and one in the struct xfs_icdinode. Now that we
no longer log the struct xfs_icdinode directly, we don't need to
keep the timestamps in this structure. instead we can copy them
straight out of the VFS inode when formatting the inode log item or
the on-disk inode.

This reduces the struct xfs_inode in size by 24 bytes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:54:58 +11:00
Dave Chinner f8d55aa052 xfs: introduce inode log format object
We currently carry around and log an entire inode core in the
struct xfs_inode. A lot of the information in the inode core is
duplicated in the VFS inode, but we cannot remove this duplication
of infomration because the inode core is logged directly in
xfs_inode_item_format().

Add a new function xfs_inode_item_format_core() that copies the
inode core data into a struct xfs_icdinode that is pulled directly
from the log vector buffer. This means we no longer directly
copy the inode core, but copy the structures one member at a time.
This will be slightly less efficient than copying, but will allow us
to remove duplicate and unnecessary items from the struct xfs_inode.

To enable us to do this, call the new structure a xfs_log_dinode,
so that we know it's different to the physical xfs_dinode and the
in-core xfs_icdinode.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:54:58 +11:00
Dave Chinner bf85e0998a xfs: RT bitmap and summary buffers need verifiers
Buffers without verifiers issue runtime warnings on XFS. We don't
have anything we can actually verify in the RT buffers (no CRCs, not
magic numbers, etc), but we still need verifiers to avoid the
warnings.

Add a set of dummy verifier operations for the realtime buffers and
apply them in the appropriate places.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:41:45 +11:00
Dave Chinner f67ca6eca8 xfs: RT bitmap and summary buffers are not typed
When logging buffers, we attach a type to them that follows the
buffer all the way into the log and is used to identify the buffer
contents in log recovery. Both the realtime summary buffers and the
bitmap buffers do not have types defined or set, so when we try to
log them we see assert failure:

XFS: Assertion failed: (bip->bli_flags & XFS_BLI_STALE) || (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF), file: fs/xfs/xfs_buf_item.c, line: 294

Fix this by adding buffer log format types for these buffers, and
add identification support into log recovery for them. Only build the log
recovery support if CONFIG_XFS_RT=y - we can't get into log recovery for real
time filesystems if support is not built into the kernel, and this avoids
potential build problems.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:41:31 +11:00
Darrick J. Wong 8e0bd4925b xfs: fix endianness error when checking log block crc on big endian platforms
Since the checksum function and the field are both __le32, don't
perform endian conversion when comparing the two.  This fixes mount
failures on ppc64.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-08 11:03:58 +11:00
Dave Chinner dde7f55bd0 Merge branch 'xfs-misc-fixes-for-4.5-2' into for-next 2016-01-12 07:04:30 +11:00
Dave Chinner 7d6a13f023 xfs: handle dquot buffer readahead in log recovery correctly
When we do dquot readahead in log recovery, we do not use a verifier
as the underlying buffer may not have dquots in it. e.g. the
allocation operation hasn't yet been replayed. Hence we do not want
to fail recovery because we detect an operation to be replayed has
not been run yet. This problem was addressed for inodes in commit
d891400 ("xfs: inode buffers may not be valid during recovery
readahead") but the problem was not recognised to exist for dquots
and their buffers as the dquot readahead did not have a verifier.

The result of not using a verifier is that when the buffer is then
next read to replay a dquot modification, the dquot buffer verifier
will only be attached to the buffer if *readahead is not complete*.
Hence we can read the buffer, replay the dquot changes and then add
it to the delwri submission list without it having a verifier
attached to it. This then generates warnings in xfs_buf_ioapply(),
which catches and warns about this case.

Fix this and make it handle the same readahead verifier error cases
as for inode buffers by adding a new readahead verifier that has a
write operation as well as a read operation that marks the buffer as
not done if any corruption is detected.  Also make sure we don't run
readahead if the dquot buffer has been marked as cancelled by
recovery.

This will result in readahead either succeeding and the buffer
having a valid write verifier, or readahead failing and the buffer
state requiring the subsequent read to resubmit the IO with the new
verifier.  In either case, this will result in the buffer always
ending up with a valid write verifier on it.

Note: we also need to fix the inode buffer readahead error handling
to mark the buffer with EIO. Brian noticed the code I copied from
there wrong during review, so fix it at the same time. Add comments
linking the two functions that handle readahead verifier errors
together so we don't forget this behavioural link in future.

cc: <stable@vger.kernel.org> # 3.12 - current
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-12 07:04:01 +11:00
Brian Foster 7088c4136f xfs: detect and trim torn writes during log recovery
Certain types of storage, such as persistent memory, do not provide
sector atomicity for writes. This means that if a crash occurs while XFS
is writing log records, only part of those records might make it to the
storage. This is problematic because log recovery uses the cycle value
packed at the top of each log block to locate the head/tail of the log.
This can lead to CRC verification failures during log recovery and an
unmountable fs for a filesystem that is otherwise consistent.

Update log recovery to incorporate log record CRC verification as part
of the head/tail discovery process. Once the head is located via the
traditional algorithm, run a CRC-only pass over the records up to the
head of the log. If CRC verification fails, assume that the records are
torn as a matter of policy and trim the head block back to the start of
the first bad record.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-05 07:40:16 +11:00
Brian Foster eed6b462fb xfs: refactor log record start detection into a new helper
As part of the head/tail discovery process, log recovery locates the
head block and then reverse seeks to find the start of the last active
record in the log. This is non-trivial as the record itself could have
wrapped around the end of the physical log. Log recovery torn write
detection potentially needs to walk further behind the last record in
the log, as multiple log I/Os can be in-flight at one time during a
crash event.

Therefore, refactor the reverse log record header search mechanism into
a new helper that supports the ability to seek past an arbitrary number
of log records (or until the tail is hit). Update the head/tail search
mechanism to call the new helper, but otherwise there is no change in
log recovery behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 15:55:10 +11:00
Brian Foster 6528250b71 xfs: support a crc verification only log record pass
Log recovery torn write detection uses CRC verification over a range of
the active log to identify torn writes. Since the generic log recovery
pass code implements a superset of the functionality required for CRC
verification, it can be easily modified to support a CRC verification
only pass.

Create a new CRC pass type and update the log record processing helper
to skip everything beyond CRC verification when in this mode. This pass
will be invoked in subsequent patches to implement torn write detection.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 15:55:10 +11:00
Brian Foster d7f37692e3 xfs: return start block of first bad log record during recovery
Each log recovery pass walks from the tail block to the head block and
processes records appropriately based on the associated log pass type.
There are various failure conditions that can occur through this
sequence, such as I/O errors, CRC errors, etc. Log torn write detection
will perform CRC verification near the head of the log to detect torn
writes and trim torn records from the log appropriately.

As it is, xlog_do_recovery_pass() only returns an error code in the
event of CRC failure, which isn't enough information to trim the head of
the log. Update xlog_do_recovery_pass() to optionally return the start
block of the associated record when an error occurs. This patch contains
no functional changes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 15:55:10 +11:00
Brian Foster b94fb2d178 xfs: refactor and open code log record crc check
Log record CRC verification currently occurs during active log recovery,
immediately before a log record is unpacked. Therefore, the CRC
calculation code is buried within the data unpack function. CRC
verification pass support only needs to go so far as check the CRC, but
this is not easily allowed as the code is currently organized.

Since we now have a new log record processing helper, pull the record
CRC verification code out from the unpack helper and open-code it at the
top of the new process helper. This facilitates the ability to modify
how records are processed based on the type of the current pass. This
patch contains no functional changes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 15:55:10 +11:00
Brian Foster 9d94901f6e xfs: refactor log record unpack and data processing
xlog_do_recovery_pass() duplicates a couple function calls related to
processing log records because the function must handle wrapping around
the end of the log if the head is behind the tail. This is implemented
as separate loops. CRC verification pass support will modify how records
are processed in both of these loops.

Rather than continue to duplicate code, factor the calls that process a
log record into a new helper and call that helper from both loops. This
patch contains no functional changes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 15:55:10 +11:00
Brian Foster a70f9fe52d xfs: detect and handle invalid iclog size set by mkfs
XFS log records have separate fields for the record size and the iclog
size used to write the record. mkfs.xfs zeroes the log and writes an
unmount record to generate a clean log for the subsequent mount. The
userspace record logging code has a bug where the iclog size (h_size)
field of the log record is hardcoded to 32k, even if a log stripe unit
is specified. The log record length is correctly extended to the stripe
unit. Since the kernel log recovery code uses the h_size field to
determine the log buffer size, this means that the kernel can attempt to
read/process records larger than the buffer size and overrun the buffer.

This has historically not been a problem because the kernel doesn't
actually run through log recovery in the clean unmount case. Instead,
the kernel detects that a single unmount record exists between the head
and tail and pushes the tail forward such that the log is viewed as
clean (head == tail). Once CRC verification is enabled, however, all
records at the head of the log are verified for CRC errors and thus we
are susceptible to overrun problems if the iclog field is not correct.

While the core problem must be fixed in userspace, this is historical
behavior that must be detected in the kernel to avoid severe side
effects such as memory corruption and crashes. Update the log buffer
size calculation code to detect this condition, warn the user and resize
the log buffer based on the log stripe unit. Return a corruption error
in cases where this does not look like a clean filesystem (i.e., the log
record header indicates more than one operation).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 15:55:10 +11:00
Dave Chinner 4e14e49a91 Merge branch 'xfs-misc-fixes-for-4.4-3' into for-next 2015-11-10 10:20:48 +11:00
Brian Foster 848ccfc8fe xfs: fix log recovery op header validation assert
Commit 89cebc84 ("xfs: validate transaction header length on log
recovery") added additional validation of the on-disk op header length
to protect from buffer overflow during log recovery. It accounts for the
fact that the transaction header can be split across multiple op
headers. It added an assert for when this occurs that verifies the
length of the second part of a split transaction header is less than a
full transaction header. In other words, it expects that the first op
header of a split transaction header includes at least some portion of
the transaction header.

This expectation is not always valid as a zero-length op header can
exist for the first op header of a split transaction header (see
xlog_recover_add_to_trans() for details). This means that the second op
header can have a valid, full length transaction header and thus the
full header is copied in xlog_recover_add_to_cont_trans(). Fix the
assert in xlog_recover_add_to_cont_trans() to handle this case correctly
and require that the op header length is less than or equal to a full
transaction header.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-10 10:10:33 +11:00
Brian Foster a45086e27d xfs: validate metadata LSNs against log on v5 superblocks
Since the onset of v5 superblocks, the LSN of the last modification has
been included in a variety of on-disk data structures. This LSN is used
to provide log recovery ordering guarantees (e.g., to ensure an older
log recovery item is not replayed over a newer target data structure).

While this works correctly from the point a filesystem is formatted and
mounted, userspace tools have some problematic behaviors that defeat
this mechanism. For example, xfs_repair historically zeroes out the log
unconditionally (regardless of whether corruption is detected). If this
occurs, the LSN of the filesystem is reset and the log is now in a
problematic state with respect to on-disk metadata structures that might
have a larger LSN. Until either the log catches up to the highest
previously used metadata LSN or each affected data structure is modified
and written out without incident (which resets the metadata LSN), log
recovery is susceptible to filesystem corruption.

This problem is ultimately addressed and repaired in the associated
userspace tools. The kernel is still responsible to detect the problem
and notify the user that something is wrong. Check the superblock LSN at
mount time and fail the mount if it is invalid. From that point on,
trigger verifier failure on any metadata I/O where an invalid LSN is
detected. This results in a filesystem shutdown and guarantees that we
do not log metadata changes with invalid LSNs on disk. Since this is a
known issue with a known recovery path, present a warning to instruct
the user how to recover.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12 15:59:25 +11:00
Dave Chinner aa493382cb Merge branch 'xfs-misc-fixes-for-4.3-2' into for-next 2015-08-20 09:28:45 +10:00
Dave Chinner fcfbe2c4ef xfs: log recovery needs to validate against sb_meta_uuid
Now that sb_uuid can be changed by the user, we cannot use this to
validate the metadata blocks being recovered belong to this
filesystem. We must check against the sb_meta_uuid as that will
remain unchanged.

There is a complication in this code - the superblock itself. We can
not check the sb_meta_uuid unconditionally, as that may not be set
on disk. Hence we must verify the superblock sb_uuid matches between
the log record and the in-core superblock.

Found by inspection after the previous two problems were found.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19 10:31:54 +10:00
Dave Chinner 5be203ad11 Merge branch 'xfs-efi-rework' into for-next 2015-08-19 10:10:47 +10:00
Brian Foster fc0d165696 xfs: fix broken icreate log item cancellation
Inode cluster buffers are invalidated and cancelled when inode chunks
are freed to notify log recovery that previous logged updates to the
metadata buffer should be skipped. This ensures that log recovery does
not overwrite buffers that might have already been reused.

On v4 filesystems, inode chunk allocation and inode updates are logged
via the cluster buffers and thus cancellation is easily detected via
buffer cancellation items. v5 filesystems use the new icreate
transaction, which uses logical logging and ordered buffers to log a
full inode chunk allocation at once. The resulting icreate item often
spans multiple inode cluster buffers.

Log recovery checks for cancelled buffers when processing icreate log
items, but it has a couple problems. First, it uses the full length of
the inode chunk rather than the cluster size. Second, it uses the length
in FSB units rather than BB units. Either of these problems prevent
icreate recovery from identifying cancelled buffers and thus inode
initialization proceeds unconditionally.

Update xlog_recover_do_icreate_pass2() to iterate the icreate range in
cluster sized increments and check each increment for cancellation.
Since icreate is currently only used for the minimum atomic inode chunk
allocation, we expect that either all or none of the buffers will be
cancelled. Cancel the icreate if at least one buffer is cancelled to
avoid making a bad situation worse by initializing a partial inode
chunk, but detect such anomalies and warn the user.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19 09:59:38 +10:00
Brian Foster 78d57e4593 xfs: icreate log item recovery and cancellation tracepoints
Various log items have recovery tracepoints to identify whether a
particular log item is recovered or cancelled. Add the equivalent
tracepoints for the icreate transaction.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19 09:58:48 +10:00
Brian Foster f0b2efad16 xfs: don't leave EFIs on AIL on mount failure
Log recovery occurs in two phases at mount time. In the first phase,
EFIs and EFDs are processed and potentially cancelled out. EFIs without
EFD objects are inserted into the AIL for processing and recovery in the
second phase. xfs_mountfs() runs various other operations between the
phases and is thus subject to failure. If failure occurs after the first
phase but before the second, pending EFIs sit on the AIL, pin it and
cause the mount to hang.

Update the mount sequence to ensure that pending EFIs are cancelled in
the event of failure. Add a recovery cancellation mechanism to iterate
the AIL and cancel all EFI items when requested. Plumb cancellation
support through the log mount finish helper and update xfs_mountfs() to
invoke cancellation in the event of failure after recovery has started.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19 09:58:36 +10:00
Brian Foster e32a1d1fbf xfs: use EFI refcount consistently in log recovery
The EFI is initialized with a reference count of 2. One for the EFI to
ensure the item makes it to the AIL and one for the subsequently created
EFD to release the EFI once the EFD is committed. Log recovery uses the
EFI in a similar manner, but implements a hack to remove both references
in one call once the EFD is handled.

Update log recovery to use EFI reference counting in a manner consistent
with the log. When an EFI is encountered during recovery, an EFI item is
allocated and inserted to the AIL directly. Since the EFI reference is
typically dropped when the EFI is unpinned and this is analogous with
AIL insertion, drop the EFI reference at this point.

When a corresponding EFD is encountered in the log, this indicates that
the extents were freed, no processing is required and the EFI can be
dropped. Update xlog_recover_efd_pass2() to simply drop the EFD
reference at this point rather than open code the AIL removal and EFI
free.

Remaining EFIs (i.e., with no corresponding EFD) are processed in
xlog_recover_finish(). An EFD transaction is allocated and the extents
are freed, which transfers ownership of the EFI reference to the EFD
item in the log.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19 09:52:21 +10:00