Darrick J. Wong [Wed, 3 Aug 2016 02:09:48 +0000 (12:09 +1000)]
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>
Darrick J. Wong [Wed, 3 Aug 2016 02:04:45 +0000 (12:04 +1000)]
xfs: create rmap update intent log items
Create rmap update intent/done log items to record redo information in
the log. Because we need to roll transactions between updating the
bmbt mapping and updating the reverse mapping, we also have to track
the status of the metadata updates that will be recorded in the
post-roll transactions, just in case we crash before committing the
final transaction. This mechanism enables log recovery to finish what
was already started.
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>
Darrick J. Wong [Wed, 3 Aug 2016 02:03:58 +0000 (12:03 +1000)]
xfs: add rmap btree insert and delete helpers
Add a couple of helper functions to encapsulate rmap btree insert and
delete operations. Add tracepoints to the update function.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 02:03:19 +0000 (12:03 +1000)]
xfs: convert unwritten status of reverse mappings
Provide a function to convert an unwritten rmap extent to a real one
and vice versa.
[ dchinner: Note that this algorithm and code was derived from the
existing bmapbt unwritten extent conversion code in
xfs_bmap_add_extent_unwritten_real(). ]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:45:12 +0000 (11:45 +1000)]
xfs: remove an extent from the rmap btree
Originally-From: Dave Chinner <dchinner@redhat.com>
Now that we have records in the rmap btree, we need to remove them
when extents are freed. This needs to find the relevant record in
the btree and remove/trim/split it accordingly.
[darrick.wong@oracle.com: make rmap routines handle the enlarged keyspace]
[dchinner: remove remaining unused debug printks]
[darrick: fix a bug when growfs in an AG with an rmap ending at EOFS]
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>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:44:21 +0000 (11:44 +1000)]
xfs: add an extent to the rmap btree
Originally-From: Dave Chinner <dchinner@redhat.com>
Now all the btree, free space and transaction infrastructure is in
place, we can finally add the code to insert reverse mappings to the
rmap btree. Freeing will be done in a separate patch, so just the
addition operation can be focussed on here.
[darrick: handle owner offsets when adding rmaps]
[dchinner: remove remaining debug printk statements]
[darrick: move unwritten bit to rm_offset]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:43:24 +0000 (11:43 +1000)]
xfs: add tracepoints for the rmap functions
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:42:39 +0000 (11:42 +1000)]
xfs: teach rmapbt to support interval queries
Now that the generic btree code supports querying all records within a
range of keys, use that functionality to allow us to ask for all the
extents mapped to a range of physical blocks.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:40:56 +0000 (11:40 +1000)]
xfs: support overlapping intervals in the rmap btree
Now that the generic btree code supports overlapping intervals, plug
in the rmap btree to this functionality. We will need it to find
potential left neighbors in xfs_rmap_{alloc,free} later in the patch
set.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:39:05 +0000 (11:39 +1000)]
xfs: add rmap btree operations
Originally-From: Dave Chinner <dchinner@redhat.com>
Implement the generic btree operations needed to manipulate rmap
btree blocks. This is very similar to the per-ag freespace btree
implementation, and uses the AGFL for allocation and freeing of
blocks.
Adapt the rmap btree to store owner offsets within each rmap record,
and to handle the primary key being redefined as the tuple
[agblk, owner, offset]. The expansion of the primary key is crucial
to allowing multiple owners per extent.
[darrick: adapt the btree ops to deal with offsets]
[darrick: remove init_rec_from_key]
[darrick: move unwritten bit to rm_offset]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:38:24 +0000 (11:38 +1000)]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:37:10 +0000 (11:37 +1000)]
xfs: rmap btree transaction reservations
The rmap btrees will use the AGFL as the block allocation source, so
we need to ensure that the transaction reservations reflect the fact
this tree is modified by allocation and freeing. Hence we need to
extend all the extent allocation/free reservations used in
transactions to handle this.
Note that this also gets rid of the unused XFS_ALLOCFREE_LOG_RES
macro, as we now do buffer reservations based on the number of
buffers logged via xfs_calc_buf_res(). Hence we only need the buffer
count calculation now.
[darrick: use rmap_maxlevels when calculating log block resv]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:36:08 +0000 (11:36 +1000)]
xfs: add rmap btree growfs support
Originally-From: Dave Chinner <dchinner@redhat.com>
Now we can read and write rmap btree blocks, we can add support to
the growfs code to initialise new rmap btree blocks.
[darrick.wong@oracle.com: fill out the rmap offset fields]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:36:07 +0000 (11:36 +1000)]
xfs: define the on-disk rmap btree format
Originally-From: Dave Chinner <dchinner@redhat.com>
Now we have all the surrounding call infrastructure in place, we can
start filling out the rmap btree implementation. Start with the
on-disk btree format; add everything needed to read, write and
manipulate rmap btree blocks. This prepares the way for adding the
btree operations implementation.
[darrick: record owner and offset info in rmap btree]
[darrick: fork, bmbt and unwritten state in rmap btree]
[darrick: flags are a separate field in xfs_rmap_irec]
[darrick: calculate maxlevels separately]
[darrick: move the 'unwritten' bit into unused parts of rm_offset]
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>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:33:43 +0000 (11:33 +1000)]
xfs: introduce rmap extent operation stubs
Originally-From: Dave Chinner <dchinner@redhat.com>
Add the stubs into the extent allocation and freeing paths that the
rmap btree implementation will hook into. While doing this, add the
trace points that will be used to track rmap btree extent
manipulations.
[darrick.wong@oracle.com: Extend the stubs to take full owner info.]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:33:42 +0000 (11:33 +1000)]
xfs: add owner field to extent allocation and freeing
For the rmap btree to work, we have to feed the extent owner
information to the the allocation and freeing functions. This
information is what will end up in the rmap btree that tracks
allocated extents. While we technically don't need the owner
information when freeing extents, passing it allows us to validate
that the extent we are removing from the rmap btree actually
belonged to the owner we expected it to belong to.
We also define a special set of owner values for internal metadata
that would otherwise have no owner. This allows us to tell the
difference between metadata owned by different per-ag btrees, as
well as static fs metadata (e.g. AG headers) and internal journal
blocks.
There are also a couple of special cases we need to take care of -
during EFI recovery, we don't actually know who the original owner
was, so we need to pass a wildcard to indicate that we aren't
checking the owner for validity. We also need special handling in
growfs, as we "free" the space in the last AG when extending it, but
because it's new space it has no actual owner...
While touching the xfs_bmap_add_free() function, re-order the
parameters to put the struct xfs_mount first.
Extend the owner field to include both the owner type and some sort
of index within the owner. The index field will be used to support
reverse mappings when reflink is enabled.
When we're freeing extents from an EFI, we don't have the owner
information available (rmap updates have their own redo items).
xfs_free_extent therefore doesn't need to do an rmap update. Make
sure that the log replay code signals this correctly.
This is based upon a patch originally from Dave Chinner. It has been
extended to add more owner information with the intent of helping
recovery operations when things go wrong (e.g. offset of user data
block in a file).
[dchinner: de-shout the xfs_rmap_*_owner helpers]
[darrick: minor style fixes suggested by Christoph Hellwig]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:31:47 +0000 (11:31 +1000)]
xfs: rmap btree add more reserved blocks
Originally-From: Dave Chinner <dchinner@redhat.com>
XFS reserves a small amount of space in each AG for the minimum
number of free blocks needed for operation. Adding the rmap btree
increases the number of reserved blocks, but it also increases the
complexity of the calculation as the free inode btree is optional
(like the rmbt).
Rather than calculate the prealloc blocks every time we need to
check it, add a function to calculate it at mount time and store it
in the struct xfs_mount, and convert the XFS_PREALLOC_BLOCKS macro
just to use the xfs-mount variable directly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:31:11 +0000 (11:31 +1000)]
xfs: add rmap btree stats infrastructure
Originally-From: Dave Chinner <dchinner@redhat.com>
The rmap btree will require the same stats as all the other generic
btrees, so add all the code for that now.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:30:32 +0000 (11:30 +1000)]
xfs: introduce rmap btree definitions
Originally-From: Dave Chinner <dchinner@redhat.com>
Add new per-ag rmap btree definitions to the per-ag structures. The
rmap btree will sit in the empty slots on disk after the free space
btrees, and hence form a part of the array of space management
btrees. This requires the definition of the btree to be contiguous
with the free space btrees.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:29:42 +0000 (11:29 +1000)]
xfs: increase XFS_BTREE_MAXLEVELS to fit the rmapbt
By my calculations, a 1,073,741,824 block AG with a 1k block size
can attain a maximum height of 9. Assuming a record size of 24
bytes, a key/ptr size of 44 bytes, and half-full btree nodes, we'd
need 53,687,092 blocks for the records and ~6 million blocks for the
keys. That requires a btree of height 9 based on the following
derivation:
Block size = 1024b
sblock CRC header = 56b
== 1024-56 = 968 bytes for tree data
rmapbt record = 24b
== 40 records per leaf block
rmapbt ptr/key = 44b
== 22 ptr/keys per block
Worst case, each block is half full, so 20 records and 11 ptrs per block.
1073741824 rmap records / 20 records per block
==
53687092 leaf blocks
53687092 leaves / 11 ptrs per block
== 4880645 level 1 blocks
== 443695 level 2 blocks
== 40336 level 3 blocks
== 3667 level 4 blocks
== 334 level 5 blocks
== 31 level 6 blocks
== 3 level 7 blocks
== 1 level 8 block
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:26:33 +0000 (11:26 +1000)]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:23:49 +0000 (11:23 +1000)]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:19:29 +0000 (11:19 +1000)]
xfs: rename flist/free_list to dfops
Mechanical change of flist/free_list to dfops, since they're now
deferred ops, not just a freeing list.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:18:10 +0000 (11:18 +1000)]
xfs: change xfs_bmap_{finish,cancel,init,free} -> xfs_defer_*
Drop the compatibility shims that we were using to integrate the new
deferred operation mechanism into the existing code. No new code.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:15:38 +0000 (11:15 +1000)]
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:14:35 +0000 (11:14 +1000)]
xfs: enable the xfs_defer mechanism to process extents to free
Connect the xfs_defer mechanism with the pieces that we'll need to
handle deferred extent freeing. We'll wire up the existing code to
our new deferred mechanism later.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:13:47 +0000 (11:13 +1000)]
xfs: clean up typedef usage in the EFI/EFD handling code
Replace structure typedefs with struct xfs_foo_* in the EFI/EFD
handling code in preparation to move it over to deferred ops.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:13:02 +0000 (11:13 +1000)]
xfs: add tracepoints for the deferred ops mechanism
Add tracepoints for the internals of the deferred ops mechanism
and tracepoint classes for clients of the dops, to make debugging
easier.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:12:25 +0000 (11:12 +1000)]
xfs: move deferred operations into a separate file
All the code around struct xfs_bmap_free basically implements a
deferred operation framework through which we can roll transactions
(to unlock buffers and avoid violating lock order rules) while
managing all the necessary log redo items. Previously we only used
this code to free extents after some sort of mapping operation, but
with the advent of rmap and reflink, we suddenly need to do more than
that.
With that in mind, xfs_bmap_free really becomes a deferred ops control
structure. Rename the structure and move the deferred ops into their
own file to avoid further bloating of the bmap code.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:10:55 +0000 (11:10 +1000)]
xfs: refactor btree owner change into a separate visit-blocks function
Refactor the btree_change_owner function into a more generic apparatus
which visits all blocks in a btree. We'll use this in a subsequent
patch for counting btree blocks for AG reservations.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:10:21 +0000 (11:10 +1000)]
xfs: introduce interval queries on btrees
Create a function to enable querying of btree records mapping to a
range of keys. This will be used in subsequent patches to allow
querying the reverse mapping btree to find the extents mapped to a
range of physical blocks, though the generic code can be used for
any range query.
The overlapped query range function needs to use the btree get_block
helper because the root block could be an inode, in which case
bc_bufs[nlevels-1] will be NULL.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:08:36 +0000 (11:08 +1000)]
xfs: support btrees with overlapping intervals for keys
On a filesystem with both reflink and reverse mapping enabled, it's
possible to have multiple rmap records referring to the same blocks on
disk. When overlapping intervals are possible, querying a classic
btree to find all records intersecting a given interval is inefficient
because we cannot use the left side of the search interval to filter
out non-matching records the same way that we can use the existing
btree key to filter out records coming after the right side of the
search interval. This will become important once we want to use the
rmap btree to rebuild BMBTs, or implement the (future) fsmap ioctl.
(For the non-overlapping case, we can perform such queries trivially
by starting at the left side of the interval and walking the tree
until we pass the right side.)
Therefore, extend the btree code to come closer to supporting
intervals as a first-class record attribute. This involves widening
the btree node's key space to store both the lowest key reachable via
the node pointer (as the btree does now) and the highest key reachable
via the same pointer and teaching the btree modifying functions to
keep the highest-key records up to date.
This behavior can be turned on via a new btree ops flag so that btrees
that cannot store overlapping intervals don't pay the overhead costs
in terms of extra code and disk format changes.
When we're deleting a record in a btree that supports overlapped
interval records and the deletion results in two btree blocks being
joined, we defer updating the high/low keys until after all possible
joining (at higher levels in the tree) have finished. At this point,
the btree pointers at all levels have been updated to remove the empty
blocks and we can update the low and high keys.
When we're doing this, we must be careful to update the keys of all
node pointers up to the root instead of stopping at the first set of
keys that don't need updating. This is because it's possible for a
single deletion to cause joining of multiple levels of tree, and so
we need to update everything going back to the root.
The diff_two_keys functions return < 0, 0, or > 0 if key1 is less than,
equal to, or greater than key2, respectively. This is consistent
with the rest of the kernel and the C library.
In btree_updkeys(), we need to evaluate the force_all parameter before
running the key diff to avoid reading uninitialized memory when we're
forcing a key update. This happens when we've allocated an empty slot
at level N + 1 to point to a new block at level N and we're in the
process of filling out the new keys.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:03:38 +0000 (11:03 +1000)]
xfs: add function pointers for get/update keys to the btree
Add some function pointers to bc_ops to get the btree keys for
leaf and node blocks, and to update parent keys of a block.
Convert the _btree_updkey calls to use our new pointer, and
modify the tree shape changing code to call the appropriate
get_*_keys pointer instead of _btree_copy_keys because the
overlapping btree has to calculate high key values.
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>
Darrick J. Wong [Wed, 3 Aug 2016 01:02:39 +0000 (11:02 +1000)]
xfs: during btree split, save new block key & ptr for future insertion
When a btree block has to be split, we pass the new block's ptr from
xfs_btree_split() back to xfs_btree_insert() via a pointer parameter;
however, we pass the block's key through the cursor's record. It is a
little weird to "initialize" a record from a key since the non-key
attributes will have garbage values.
When we go to add support for interval queries, we have to be able to
pass the lowest and highest keys accessible via a pointer. There's no
clean way to pass this back through the cursor's record field.
Therefore, pass the key directly back to xfs_btree_insert() the same
way that we pass the btree_ptr.
As a bonus, we no longer need init_rec_from_key and can drop it from the
codebase.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:01:25 +0000 (11:01 +1000)]
xfs: set *stat=1 after iroot realloc
If we make the inode root block of a btree unfull by expanding the
root, we must set *stat to 1 to signal success, rather than leaving
it uninitialized.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 01:00:42 +0000 (11:00 +1000)]
xfs: fix locking of the rt bitmap/summary inodes
When we're deleting realtime extents, we need to lock the summary
inode in case we need to update the summary info to prevent an assert
on the rsumip inode lock on a debug kernel. While we're at it, fix
the locking annotations so that we avoid triggering lockdep warnings.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 00:59:42 +0000 (10:59 +1000)]
xfs: fix attr shortform structure alignment on cris
Apparently cris doesn't require structure stride to align with the
largest type in the struct, so list[0] isn't at offset 4 like it is
everywhere else. Fix this... insofar as existing XFSes on cris are
screwed.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Wed, 3 Aug 2016 00:58:53 +0000 (10:58 +1000)]
xfs: in _attrlist_by_handle, copy the cursor back to userspace
When we're iterating inode xattrs by handle, we have to copy the
cursor back to userspace so that a subsequent invocation actually
retrieves subsequent contents.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Fri, 22 Jul 2016 04:10:56 +0000 (14:10 +1000)]
Merge branch 'xfs-4.8-misc-fixes-4' into for-next
Dave Chinner [Fri, 22 Jul 2016 04:10:18 +0000 (14:10 +1000)]
xfs: remove EXPERIMENTAL tag from sparse inode feature
Been around for long enough now, hasn't caused any regression test
failures in the past 3 months, so it's time to make it a fully
supported feature.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Thu, 21 Jul 2016 23:56:38 +0000 (09:56 +1000)]
xfs: bufferhead chains are invalid after end_page_writeback
In xfs_finish_page_writeback(), we have a loop that looks like this:
do {
if (off < bvec->bv_offset)
goto next_bh;
if (off > end)
break;
bh->b_end_io(bh, !error);
next_bh:
off += bh->b_size;
} while ((bh = bh->b_this_page) != head);
The b_end_io function is end_buffer_async_write(), which will call
end_page_writeback() once all the buffers have marked as no longer
under IO. This issue here is that the only thing currently
protecting both the bufferhead chain and the page from being
reclaimed is the PageWriteback state held on the page.
While we attempt to limit the loop to just the buffers covered by
the IO, we still read from the buffer size and follow the next
pointer in the bufferhead chain. There is no guarantee that either
of these are valid after the PageWriteback flag has been cleared.
Hence, loops like this are completely unsafe, and result in
use-after-free issues. One such problem was caught by Calvin Owens
with KASAN:
.....
INFO: Freed in 0x103fc80ec age=
18446651500051355200 cpu=
2165122683 pid=-1
free_buffer_head+0x41/0x90
__slab_free+0x1ed/0x340
kmem_cache_free+0x270/0x300
free_buffer_head+0x41/0x90
try_to_free_buffers+0x171/0x240
xfs_vm_releasepage+0xcb/0x3b0
try_to_release_page+0x106/0x190
shrink_page_list+0x118e/0x1a10
shrink_inactive_list+0x42c/0xdf0
shrink_zone_memcg+0xa09/0xfa0
shrink_zone+0x2c3/0xbc0
.....
Call Trace:
<IRQ> [<
ffffffff81e8b8e4>] dump_stack+0x68/0x94
[<
ffffffff8153a995>] print_trailer+0x115/0x1a0
[<
ffffffff81541174>] object_err+0x34/0x40
[<
ffffffff815436e7>] kasan_report_error+0x217/0x530
[<
ffffffff81543b33>] __asan_report_load8_noabort+0x43/0x50
[<
ffffffff819d651f>] xfs_destroy_ioend+0x3bf/0x4c0
[<
ffffffff819d69d4>] xfs_end_bio+0x154/0x220
[<
ffffffff81de0c58>] bio_endio+0x158/0x1b0
[<
ffffffff81dff61b>] blk_update_request+0x18b/0xb80
[<
ffffffff821baf57>] scsi_end_request+0x97/0x5a0
[<
ffffffff821c5558>] scsi_io_completion+0x438/0x1690
[<
ffffffff821a8d95>] scsi_finish_command+0x375/0x4e0
[<
ffffffff821c3940>] scsi_softirq_done+0x280/0x340
Where the access is occuring during IO completion after the buffer
had been freed from direct memory reclaim.
Prevent use-after-free accidents in this end_io processing loop by
pre-calculating the loop conditionals before calling bh->b_end_io().
The loop is already limited to just the bufferheads covered by the
IO in progress, so the offset checks are sufficient to prevent
accessing buffers in the chain after end_page_writeback() has been
called by the the bh->b_end_io() callout.
Yet another example of why Bufferheads Must Die.
cc: <stable@vger.kernel.org> # 4.7
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reported-and-Tested-by: Calvin Owens <calvinowens@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Thu, 21 Jul 2016 23:52:35 +0000 (09:52 +1000)]
xfs: allocate log vector buffers outside CIL context lock
One of the problems we currently have with delayed logging is that
under serious memory pressure we can deadlock memory reclaim. THis
occurs when memory reclaim (such as run by kswapd) is reclaiming XFS
inodes and issues a log force to unpin inodes that are dirty in the
CIL.
The CIL is pushed, but this will only occur once it gets the CIL
context lock to ensure that all committing transactions are complete
and no new transactions start being committed to the CIL while the
push switches to a new context.
The deadlock occurs when the CIL context lock is held by a
committing process that is doing memory allocation for log vector
buffers, and that allocation is then blocked on memory reclaim
making progress. Memory reclaim, however, is blocked waiting for
a log force to make progress, and so we effectively deadlock at this
point.
To solve this problem, we have to move the CIL log vector buffer
allocation outside of the context lock so that memory reclaim can
always make progress when it needs to force the log. The problem
with doing this is that a CIL push can take place while we are
determining if we need to allocate a new log vector buffer for
an item and hence the current log vector may go away without
warning. That means we canot rely on the existing log vector being
present when we finally grab the context lock and so we must have a
replacement buffer ready to go at all times.
To ensure this, introduce a "shadow log vector" buffer that is
always guaranteed to be present when we gain the CIL context lock
and format the item. This shadow buffer may or may not be used
during the formatting, but if the log item does not have an existing
log vector buffer or that buffer is too small for the new
modifications, we swap it for the new shadow buffer and format
the modifications into that new log vector buffer.
The result of this is that for any object we modify more than once
in a given CIL checkpoint, we double the memory required
to track dirty regions in the log. For single modifications then
we consume the shadow log vectorwe allocate on commit, and that gets
consumed by the checkpoint. However, if we make multiple
modifications, then the second transaction commit will allocate a
shadow log vector and hence we will end up with double the memory
usage as only one of the log vectors is consumed by the CIL
checkpoint. The remaining shadow vector will be freed when th elog
item is freed.
This can probably be optimised in future - access to the shadow log
vector is serialised by the object lock (as opposited to the active
log vector, which is controlled by the CIL context lock) and so we
can probably free shadow log vector from some objects when the log
item is marked clean on removal from the AIL.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Thu, 21 Jul 2016 23:51:05 +0000 (09:51 +1000)]
libxfs: directory node splitting does not have an extra block
xfsprogs source commit
4280e59dcbc4cd8e01585efe788a68eb378048e8
xfs_da3_split() has to handle all three versions of the
directory/attribute btree structure. The attr tree is v1, the dir
tre is v2 or v3. The main difference between the v1 and v2/3 trees
is the way tree nodes are split - in the v1 tree we can require a
double split to occur because the object to be inserted may be
larger than the space made by splitting a leaf. In this case we need
to do a double split - one to split the full leaf, then another to
allocate an empty leaf block in the correct location for the new
entry. This does not happen with dir (v2/v3) formats as the objects
being inserted are always guaranteed to fit into the new space in
the split blocks.
Indeed, for directories they *may* be an extra block on this buffer
pointer. However, it's guaranteed not to be a leaf block (i.e. a
directory data block) - the directory code only ever places hash
index or free space blocks in this pointer (as a cursor of
sorts), and so to use it as a directory data block will immediately
corrupt the directory.
The problem is that the code assumes that there may be extra blocks
that we need to link into the tree once we've split the root, but
this is not true for either dir or attr trees, because the extra
attr block is always consumed by the last node split before we split
the root. Hence the linking in an extra block is always wrong at the
root split level, and this manifests itself in repair as a directory
corruption in a repaired directory, leaving the directory rebuild
incomplete.
This is a dir v2 zero-day bug - it was in the initial dir v2 commit
that was made back in February 1998.
Fix this by ensuring the linking of the blocks after the root split
never tries to make use of the extra blocks that may be held in the
cursor. They are held there for other purposes and should never be
touched by the root splitting code.
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>
Arnd Bergmann [Thu, 21 Jul 2016 23:50:55 +0000 (09:50 +1000)]
xfs: remove dax code from object file when disabled
We check IS_DAX(inode) before calling either xfs_file_dax_read or
xfs_file_dax_write, and this will lead the call being optimized out at
compile time when CONFIG_FS_DAX is disabled.
However, the two functions are marked STATIC, so they become global
symbols when CONFIG_XFS_DEBUG is set, leaving us with two unused global
functions that call into an undefined function and a broken "allmodconfig"
build:
fs/built-in.o: In function `xfs_file_dax_read':
fs/xfs/xfs_file.c:348: undefined reference to `dax_do_io'
fs/built-in.o: In function `xfs_file_dax_write':
fs/xfs/xfs_file.c:758: undefined reference to `dax_do_io'
Marking the two functions 'static noinline' instead of 'STATIC' will let
the compiler drop the symbols when there are no callers but avoid the
implicit inlining.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes:
16d4d43595b4 ("xfs: split direct I/O and DAX path")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Thu, 21 Jul 2016 23:50:38 +0000 (09:50 +1000)]
xfs: skip dirty pages in ->releasepage()
XFS has had scattered reports of delalloc blocks present at
->releasepage() time. This results in a warning with a stack trace
similar to the following:
...
Call Trace:
[<
ffffffffa23c5b8f>] dump_stack+0x63/0x84
[<
ffffffffa20837a7>] warn_slowpath_common+0x97/0xe0
[<
ffffffffa208380a>] warn_slowpath_null+0x1a/0x20
[<
ffffffffa2326caf>] xfs_vm_releasepage+0x10f/0x140
[<
ffffffffa218c680>] ? page_mkclean_one+0xd0/0xd0
[<
ffffffffa218d3a0>] ? anon_vma_prepare+0x150/0x150
[<
ffffffffa21521c2>] try_to_release_page+0x32/0x50
[<
ffffffffa2166b2e>] shrink_active_list+0x3ce/0x3e0
[<
ffffffffa21671c7>] shrink_lruvec+0x687/0x7d0
[<
ffffffffa21673ec>] shrink_zone+0xdc/0x2c0
[<
ffffffffa2168539>] kswapd+0x4f9/0x970
[<
ffffffffa2168040>] ? mem_cgroup_shrink_node_zone+0x1a0/0x1a0
[<
ffffffffa20a0d99>] kthread+0xc9/0xe0
[<
ffffffffa20a0cd0>] ? kthread_stop+0x100/0x100
[<
ffffffffa26b404f>] ret_from_fork+0x3f/0x70
[<
ffffffffa20a0cd0>] ? kthread_stop+0x100/0x100
This occurs because it is possible for shrink_active_list() to send
pages marked dirty to ->releasepage() when certain buffer_head threshold
conditions are met. shrink_active_list() doesn't check the page dirty
state apparently to handle an old ext3 corner case where in some cases
clean pages would not have the dirty bit cleared, thus it is up to the
filesystem to determine how to handle the page.
XFS currently handles the delalloc case properly, but this behavior
makes the warning spurious. Update the XFS ->releasepage() handler to
explicitly skip dirty pages. Retain the existing delalloc/unwritten
checks so we continue to warn if such buffers exist on clean pages when
they shouldn't.
Diagnosed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Wed, 20 Jul 2016 01:54:59 +0000 (11:54 +1000)]
Merge branch 'xfs-4.8-dir2-sf-fixes' into for-next
Dave Chinner [Wed, 20 Jul 2016 01:54:37 +0000 (11:54 +1000)]
Merge branch 'xfs-4.8-split-dax-dio' into for-next
Dave Chinner [Wed, 20 Jul 2016 01:53:35 +0000 (11:53 +1000)]
Merge branch 'xfs-4.8-buf-fixes' into for-next
Dave Chinner [Wed, 20 Jul 2016 01:51:08 +0000 (11:51 +1000)]
Merge branch 'xfs-4.8-misc-fixes-3' into for-next
Christoph Hellwig [Wed, 20 Jul 2016 01:48:46 +0000 (11:48 +1000)]
xfs: remove __arch_pack
Instead we always declare struct xfs_dir2_sf_hdr as packed. That's
the expected layout, and while most major architectures do the packing
by default the new structure size and offset checker showed that not
only the ARM old ABI got this wrong, but various minor embedded
architectures did as well.
[Verified that no code change on x86-64 results from this change]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:48:31 +0000 (11:48 +1000)]
xfs: kill xfs_dir2_inou_t
And use an array of unsigned char values directly to avoid problems
with architectures that pad the size of structures. This also gets
rid of the xfs_dir2_ino4_t and xfs_dir2_ino8_t types, and introduces
new constants for the size of 4 and 8 bytes as well as the size
difference between the two.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:47:21 +0000 (11:47 +1000)]
xfs: kill xfs_dir2_sf_off_t
Just use an array of two unsigned chars directly to avoid problems
with architectures that pad the size of structures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:38:55 +0000 (11:38 +1000)]
xfs: split direct I/O and DAX path
So far the DAX code overloaded the direct I/O code path. There is very little
in common between the two, and untangling them allows to clean up both variants.
As a side effect we also get separate trace points for both I/O types.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:38:01 +0000 (11:38 +1000)]
xfs: direct calls in the direct I/O path
We control both the callers and callees of ->direct_IO, so remove the
indirect calls.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:36:57 +0000 (11:36 +1000)]
xfs: stop using generic_file_read_iter for direct I/O
XFS already implement it's own flushing of the pagecache because it
implements proper synchronization for direct I/O reads. This means
calling generic_file_read_iter for direct I/O is rather useless,
as it doesn't do much but updating the atime and iocb position for
us. This also gets rid of the buffered I/O fallback that isn't used
for XFS.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:35:42 +0000 (11:35 +1000)]
xfs: split xfs_file_read_iter into buffered and direct I/O helpers
Similar to what we did on the write side a while ago.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:31:53 +0000 (11:31 +1000)]
xfs: remove s_maxbytes enforcement in xfs_file_read_iter
All the three low-level read implementations that we might call already
take care of not overflowing the maximum supported bytes, no need to
duplicate it here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:31:42 +0000 (11:31 +1000)]
xfs: kill ioflags
Now that we have the direct I/O kiocb flag there is no real need to sample
the value inside of XFS, and the invis flag was always just partially used
and isn't worth keeping this infrastructure around for. This also splits
the read tracepoint into buffered vs direct as we've done for writes a long
time ago.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 20 Jul 2016 01:29:35 +0000 (11:29 +1000)]
xfs: don't pass ioflags around in the ioctl path
Instead check the file pointer for the invisble I/O flag directly, and
use the chance to drop redundant arguments from the xfs_ioc_space
prototype.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Wed, 20 Jul 2016 01:15:28 +0000 (11:15 +1000)]
xfs: track and serialize in-flight async buffers against unmount
Newly allocated XFS metadata buffers are added to the LRU once the hold
count is released, which typically occurs after I/O completion. There is
no other mechanism at current that tracks the existence or I/O state of
a new buffer. Further, readahead I/O tends to be submitted
asynchronously by nature, which means the I/O can remain in flight and
actually complete long after the calling context is gone. This means
that file descriptors or any other holds on the filesystem can be
released, allowing the filesystem to be unmounted while I/O is still in
flight. When I/O completion occurs, core data structures may have been
freed, causing completion to run into invalid memory accesses and likely
to panic.
This problem is reproduced on XFS via directory readahead. A filesystem
is mounted, a directory is opened/closed and the filesystem immediately
unmounted. The open/close cycle triggers a directory readahead that if
delayed long enough, runs buffer I/O completion after the unmount has
completed.
To address this problem, add a mechanism to track all in-flight,
asynchronous buffers using per-cpu counters in the buftarg. The buffer
is accounted on the first I/O submission after the current reference is
acquired and unaccounted once the buffer is returned to the LRU or
freed. Update xfs_wait_buftarg() to wait on all in-flight I/O before
walking the LRU list. Once in-flight I/O has completed and the workqueue
has drained, all new buffers should have been released onto the LRU.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Wed, 20 Jul 2016 01:13:43 +0000 (11:13 +1000)]
xfs: exclude never-released buffers from buftarg I/O accounting
The upcoming buftarg I/O accounting mechanism maintains a count of
all buffers that have undergone I/O in the current hold-release
cycle. Certain buffers associated with core infrastructure (e.g.,
the xfs_mount superblock buffer, log buffers) are never released,
however. This means that accounting I/O submission on such buffers
elevates the buftarg count indefinitely and could lead to lockup on
unmount.
Define a new buffer flag to explicitly exclude buffers from buftarg
I/O accounting. Set the flag on the superblock and associated log
buffers.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Eric Sandeen [Wed, 20 Jul 2016 00:54:09 +0000 (10:54 +1000)]
xfs: don't reset b_retries to 0 on every failure
With the code as it stands today, b_retries never increments because
it gets reset to 0 in the error callback.
Remove that, and fix a similar problem where the first retry time
was constantly being overwritten, which defeated the timeout tunable
as well. We now only set first retry time if a non-zero timeout is
set, to match the behavior of only incrementing retries if a retry
value is set.
This way max retries & timeouts consistently take effect after a
tunable is set, rather than acting retroactively on a buffer which
has failed at some point in the past and has accumulated state from
those prior failures.
Thanks to dchinner for talking through this with me.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Eric Sandeen [Wed, 20 Jul 2016 00:53:22 +0000 (10:53 +1000)]
xfs: remove extraneous buffer flag changes
Fix up a couple places where extra flag manipulation occurs.
In the first case we clear XBF_ASYNC and then immediately reset it -
so don't bother clearing in the first place.
In the 2nd case we are at a point in the function where the buffer
must already be async, so there is no need to reset it.
Add consistent spacing around the " | " while we're at it.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Eric Sandeen [Wed, 20 Jul 2016 00:48:51 +0000 (10:48 +1000)]
xfs: fix xfs_error_get_cfg for negative errnos
xfs_error_get_cfg() is called with bp->b_error as an arg, which is
negative, so the switch statement won't ever find any matches.
This results in only the default error handler having any effect, as
EIO/ENOSPC/ENODEV get ignored due to the wrong sign.
It seems simplest to always flip the error sign to positive, so that
we can handle either negative errors in bp->b_error, or possibly a
positive errno via something like xfs_error_get_cfg(EIO) - this
future-proofs the function.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Hou Tao [Wed, 20 Jul 2016 00:43:11 +0000 (10:43 +1000)]
xfs: remove the magic numbers in xfs_btree_block-related len macros
replace the magic numbers by offsetof(...) and sizeof(...), and add two
extra checks on xfs_check_ondisk_structs()
[dchinner: renamed header structures to be more descriptive]
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Kaho Ng [Wed, 20 Jul 2016 00:37:50 +0000 (10:37 +1000)]
xfs: indentation fix in xfs_btree_get_iroot()
The indentation in this function is different from the other functions.
Those spacebars are converted to tabs to improve readability.
Signed-off-by: Kaho Ng <ngkaho1234@gmail.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dan Carpenter [Wed, 20 Jul 2016 00:37:13 +0000 (10:37 +1000)]
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>
Jann Horn [Wed, 20 Jul 2016 00:30:30 +0000 (10:30 +1000)]
xfs: fix type confusion in xfs_ioc_swapext
When calling fdget() in xfs_ioc_swapext(), we need to verify that
the file descriptors passed into the ioctl point to XFS inodes
before we start operations on them. If we don't do this, we could be
referencing arbitrary kernel memory as an XFS inode. THis could lead
to memory corruption and/or performing locking operations on
attacker-chosen structures in kernel memory.
[dchinner: rewrite commit message ]
[dchinner: add comment explaining new check ]
Signed-off-by: Jann Horn <jann@thejh.net>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Tue, 21 Jun 2016 01:55:13 +0000 (11:55 +1000)]
Merge branch 'xfs-4.8-misc-fixes-2' into for-next
Darrick J. Wong [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: refactor btree maxlevels computation
Create a common function to calculate the maximum height of a per-AG
btree. This will eventually be used by the rmapbt and refcountbt
code to calculate appropriate maxlevels values for each. This is
important because the verifiers and the transaction block
reservations depend on accurate estimates of how many blocks are
needed to satisfy a btree split.
We were mistakenly using the max bnobt height for all the btrees,
which creates a dangerous situation since the larger records and
keys in an rmapbt make it very possible that the rmapbt will be
taller than the bnobt and so we can run out of transaction block
reservation.
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>
Darrick J. Wong [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: convert list of extents to free into a regular list
In struct xfs_bmap_free, convert the open-coded free extent list to
a regular list, then use list_sort to sort it prior to processing.
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>
Dave Chinner [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: separate freelist fixing into a separate helper
Break up xfs_free_extent() into a helper that fixes the freelist.
This helper will be used subsequently to ensure the freelist during
deferred rmap processing.
[darrick: refactor to put this at the head of the patchset]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: rearrange xfs_bmap_add_free parameters
This is already in xfsprogs' libxfs, so port it to the kernel.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: check for a valid error_tag in errortag_add
Currently we don't check the error_tag when someone's trying to set up
error injection testing. If userspace passes in a value we don't know
about, send back an error. This will help xfstests to _notrun a test
that uses error injection to test things like log replay.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: enable buffer deadlock postmortem diagnosis via ftrace
Create a second buf_trylock tracepoint so that we can distinguish
between a successful and a failed trylock. With this piece, we can
use a script to look at the ftrace output to detect buffer deadlocks.
[dchinner: update to if/else as per hch's suggestion]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Darrick J. Wong [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: check offsets of variable length structures
Some of the directory/attr structures contain variable-length objects,
so the enclosing structure doesn't have a meaningful fixed size at
compile time. We can check the offsets of the members before the
variable-length member, so do those.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: refactor xfs_reserve_blocks() to handle ENOSPC correctly
xfs_reserve_blocks() is responsible to update the XFS reserved block
pool count at mount time or based on user request. When the caller
requests to increase the reserve pool, blocks must be allocated from
the global counters such that they are no longer available for
general purpose use. If the requested reserve pool size is too
large, XFS reserves what blocks are available. The implementation
requires looking at the percpu counters and making an educated guess
as to how many blocks to try and allocate from xfs_mod_fdblocks(),
which can return -ENOSPC if the guess was not accurate due to
counters being modified in parallel.
xfs_reserve_blocks() retries the guess in this scenario until the
allocation succeeds or it is determined that there is no space
available in the fs. While not easily reproducible in the current
form, the retry code doesn't actually work correctly if
xfs_mod_fdblocks() actually fails. The problem is that the percpu
calculations use the m_resblks counter to determine how many blocks
to allocate, but unconditionally update m_resblks before the block
allocation has actually succeeded. Therefore, if xfs_mod_fdblocks()
fails, the code jumps to the retry label and uses the already
updated m_resblks value to determine how many blocks to try and
allocate. If the percpu counters previously suggested that the
entire request was available, fdblocks_delta could end up set to 0.
In that case, m_resblks is updated to the requested value, yet no
blocks have been reserved at all.
Refactor xfs_reserve_blocks() to use an explicit loop and make the
code easier to follow. Since we have to drop the spinlock across the
xfs_mod_fdblocks() call, use a delta value for m_resblks as well and
only apply the delta once allocation succeeds.
[dchinner: convert to do {} while() loop]
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Tue, 21 Jun 2016 01:53:28 +0000 (11:53 +1000)]
xfs: cancel eofblocks background trimming on remount read-only
The filesystem quiesce sequence performs the operations necessary to
drain all background work, push pending transactions through the log
infrastructure and wait on I/O resulting from the final AIL push. We
have had reports of remount,ro hangs in xfs_log_quiesce() ->
xfs_wait_buftarg(), however, and some instrumentation code to detect
transaction commits at this point in the quiesce sequence has inculpated
the eofblocks background scanner as a cause.
While higher level remount code generally prevents user modifications by
the time the filesystem has made it to xfs_log_quiesce(), the background
scanner may still be alive and can perform pending work at any time. If
this occurs between the xfs_log_force() and xfs_wait_buftarg() calls
within xfs_log_quiesce(), this can lead to an indefinite lockup in
xfs_wait_buftarg().
To prevent this problem, cancel the background eofblocks scan worker
during the remount read-only quiesce sequence. This suspends background
trimming when a filesystem is remounted read-only. This is only done in
the remount path because the freeze codepath has already locked out new
transactions by the time the filesystem attempts to quiesce (and thus
waiting on an active work item could deadlock). Kick the eofblocks
worker to pick up where it left off once an fs is remounted back to
read-write.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Tue, 21 Jun 2016 00:10:38 +0000 (10:10 +1000)]
Merge branch 'xfs-4.8-iomap-write' into for-next
Dave Chinner [Tue, 21 Jun 2016 00:10:19 +0000 (10:10 +1000)]
Merge branch 'fs-4.8-iomap-infrastructure' into for-next
Christoph Hellwig [Tue, 21 Jun 2016 00:02:23 +0000 (10:02 +1000)]
xfs: kill xfs_zero_remaining_bytes
Instead punch the whole first, and the use the our zeroing helper
to punch out the edge blocks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Tue, 21 Jun 2016 00:00:55 +0000 (10:00 +1000)]
xfs: split xfs_free_file_space in manageable pieces
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:57:26 +0000 (09:57 +1000)]
xfs: use xfs_zero_range in xfs_zero_eof
We now skip holes in it, so no need to have the caller do it as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:56:26 +0000 (09:56 +1000)]
xfs: handle 64-bit length in xfs_iozero
We'll want to use this code for large offsets now that we're
skipping holes and unwritten extents efficiently. Also rename it to
xfs_zero_range to be a bit more descriptive, and tell the caller if
we actually did any zeroing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:55:18 +0000 (09:55 +1000)]
xfs: use iomap infrastructure for DAX zeroing
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:54:53 +0000 (09:54 +1000)]
xfs: use iomap fiemap implementation
Note that this removes support for the untested FIEMAP_FLAG_XATTR. It
could be added relatively easily with iomap ops for the attr fork, but
without test coverage I don't feel safe doing this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:53:45 +0000 (09:53 +1000)]
xfs: remove buffered write support from __xfs_get_blocks
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:53:44 +0000 (09:53 +1000)]
xfs: implement iomap based buffered write path
Convert XFS to use the new iomap based multipage write path. This involves
implementing the ->iomap_begin and ->iomap_end methods, and switching the
buffered file write, page_mkwrite and xfs_iozero paths to the new iomap
helpers.
With this change __xfs_get_blocks will never be used for buffered writes,
and the code handling them can be removed.
Based on earlier code from Dave Chinner.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:52:47 +0000 (09:52 +1000)]
xfs: reorder zeroing and flushing sequence in truncate
Currently zeroing out blocks and waiting for writeout is a bit of a mess in
truncate. This patch gives it a clear order in preparation for the iomap
path:
(1) we first wait for any direct I/O to complete to prevent any races
for it
(2) we then perform the actual zeroing, and only use the truncate_page
helpers for truncating down. The truncate up case already is
handled by the separate call to xfs_zero_eof.
(3) only then we write back dirty data, as zeroing block may cause
dirty pages when using either xfs_zero_eof or the new iomap
infrastructure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:52:47 +0000 (09:52 +1000)]
xfs: make xfs_bmbt_to_iomap available outside of xfs_pnfs.c
And ensure it works for RT subvolume files an set the block device,
both of which will be needed to be able to use the function in the
buffered write path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:38:45 +0000 (09:38 +1000)]
fs: iomap based fiemap implementation
Add a simple fiemap implementation based on iomap_ops, partially based
on a previous implementation from Bob Peterson <rpeterso@redhat.com>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:31:39 +0000 (09:31 +1000)]
fs: support DAX based iomap zeroing
This avoid needing a separate inefficient get_block based DAX zero_range
implementation in file systems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:23:11 +0000 (09:23 +1000)]
fs: introduce iomap infrastructure
Add infrastructure for multipage buffered writes. This is implemented
using an main iterator that applies an actor function to a range that
can be written.
This infrastucture is used to implement a buffered write helper, one
to zero file ranges and one to implement the ->page_mkwrite VM
operations. All of them borrow a fair amount of code from fs/buffers.
for now by using an internal version of __block_write_begin that
gets passed an iomap and builds the corresponding buffer head.
The file system is gets a set of paired ->iomap_begin and ->iomap_end
calls which allow it to map/reserve a range and get a notification
once the write code is finished with it.
Based on earlier code from Dave Chinner.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Mon, 20 Jun 2016 23:22:39 +0000 (09:22 +1000)]
fs: move struct iomap from exportfs.h to a separate header
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Dave Chinner [Wed, 1 Jun 2016 07:38:15 +0000 (17:38 +1000)]
xfs: reduce lock hold times in buffer writeback
When we have a lot of metadata to flush from the AIL, the buffer
list can get very long. The current submission code tries to batch
submission to optimise IO order of the metadata (i.e. ascending
block order) to maximise block layer merging or IO to adjacent
metadata blocks.
Unfortunately, the method used can result in long lock times
occurring as buffers locked early on in the buffer list might not be
dispatched until the end of the IO licst processing. This is because
sorting does not occur util after the buffer list has been processed
and the buffers that are going to be submitted are locked. Hence
when the buffer list is several thousand buffers long, the lock hold
times before IO dispatch can be significant.
To fix this, sort the buffer list before we start trying to lock and
submit buffers. This means we can now submit buffers immediately
after they are locked, allowing merging to occur immediately on the
plug and dispatch to occur as quickly as possible. This means there
is minimal delay between locking the buffer and IO submission
occuring, hence reducing the worst case lock hold times seen during
delayed write buffer IO submission signficantly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Christoph Hellwig [Wed, 1 Jun 2016 07:38:15 +0000 (17:38 +1000)]
xfs: define XFS_IOC_FREEZE even if FIFREEZE is defined
And the same for XFS_IOC_THAW. Just because we now have a common
version of the ioctl we still need to provide the old name for it
for anyone using those.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Eric Sandeen [Wed, 1 Jun 2016 07:38:15 +0000 (17:38 +1000)]
xfs: make several functions static
Al Viro noticed that xfs_lock_inodes should be static, and
that led to ... a few more.
These are just the easy ones, others require moving functions
higher in source files, so that's not done here to keep
this review simple.
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Wed, 1 Jun 2016 07:38:15 +0000 (17:38 +1000)]
xfs: remove spurious shutdown type check from xfs_bmap_finish()
The static checker reports that after commit
8d99fe92fed0 ("xfs: fix
efi/efd error handling to avoid fs shutdown hangs"), the code has been
reworked such that error == -EFSCORRUPTED is not possible in this
codepath.
Remove the spurious error check and just use SHUTDOWN_META_IO_ERROR
unconditionally.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Brian Foster [Wed, 1 Jun 2016 07:38:12 +0000 (17:38 +1000)]
xfs: fix broken multi-fsb buffer logging
Multi-block buffers are logged based on buffer offset in
xfs_trans_log_buf(). xfs_buf_item_log() ultimately walks each mapping in
the buffer and marks the associated range to be logged in the
xfs_buf_log_format bitmap for that mapping. This code is broken,
however, in that it marks the actual buffer offsets of the associated
range in each bitmap rather than shifting to the byte range for that
particular mapping.
For example, on a 4k fsb fs, buffer offset 4096 refers to the first byte
of the second mapping in the buffer. This means byte 0 of the second log
format bitmap should be tagged as dirty. Instead, the current code marks
byte offset 4096 of the second log format bitmap, which is invalid and
potentially out of range of the mapping.
As a result of this, the log item format code invoked at transaction
commit time is not be able to correctly identify what parts of the
buffer to copy into log vectors. This can lead to NULL log vector
pointer dereferences in CIL push context if the item format code was not
able to locate any dirty ranges at all. This crash has been reproduced
on a 4k FSB filesystem using 16k directory blocks where an unlink
operation happened not to log anything in the first block of the
mapping. The logged offsets were all over 4k, marked as such in the
subsequent log format mappings, and thus left the transaction with an
xfs_log_item that is marked DIRTY but without any logged regions.
Further, even when the logged regions are marked correctly in the buffer
log format bitmaps, the format code doesn't copy the correct ranges of
the buffer into the log. This means that any logged region beyond the
first block of a multi-block buffer is subject to corruption after a
crash and log recovery sequence. This is due to a failure to convert the
mapping bm_len field from basic blocks to bytes in the buffer offset
tracking code in xfs_buf_item_format().
Update xfs_buf_item_log() to convert buffer offsets to segment relative
offsets when logging multi-block buffers. This ensures that the modified
regions of a buffer are logged correctly and avoids the aforementioned
crash. Also update xfs_buf_item_format() to correctly track the source
offset into the buffer for the log vector formatting code. This ensures
that the correct data is copied into the log.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Linus Torvalds [Sun, 29 May 2016 16:29:24 +0000 (09:29 -0700)]
Linux 4.7-rc1