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path: root/fs/xfs/libxfs/xfs_bmap.c
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2017-02-02xfs: filter out obviously bad btree pointersDarrick J. Wong
Don't let anybody load an obviously bad btree pointer. Since the values come from disk, we must return an error, not just ASSERT. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2017-01-30xfs: remove boilerplate around xfs_btree_init_blockEric Sandeen
Now that xfs_btree_init_block_int is able to determine crc status from the passed-in mp, we can determine the proper magic as well if we are given a btree number, rather than an explicit magic value. Change xfs_btree_init_block[_int] callers to pass in the btree number, and let xfs_btree_init_block_int use the xfs_magics array via the xfs_btree_magic macro to determine which magic value is needed. This makes all of the if (crc) / else stanzas identical, and the if/else can be removed, leading to a single, common init_block call. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-30xfs: glean crc status from mp not flags in xfs_btree_init_block_intEric Sandeen
xfs_btree_init_block_int() can determine whether crcs are in effect without the passed-in XFS_BTREE_CRC_BLOCKS flag; the mp argument allows us to determine this from the superblock. Remove the flag from callers, and use xfs_sb_version_hascrc(&mp->m_sb) internally instead. This removes one difference between the if & else cases in the callers. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-25xfs: extsize hints are not unlikely in xfs_bmap_btallocxfs-for-linus-4.10-rc6-2Christoph Hellwig
With COW files they are the hotpath, just like for files with the extent size hint attribute. We really shouldn't micro-manage anything but failure cases with unlikely. Additionally Arnd Bergmann recently reported that one of these two unlikely annotations causes link failures together with an upcoming kernel instrumentation patch, so let's get rid of it ASAP. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-23xfs: fix COW writeback raceChristoph Hellwig
Due to the way how xfs_iomap_write_allocate tries to convert the whole found extents from delalloc to real space we can run into a race condition with multiple threads doing writes to this same extent. For the non-COW case that is harmless as the only thing that can happen is that we call xfs_bmapi_write on an extent that has already been converted to a real allocation. For COW writes where we move the extent from the COW to the data fork after I/O completion the race is, however, not quite as harmless. In the worst case we are now calling xfs_bmapi_write on a region that contains hole in the COW work, which will trip up an assert in debug builds or lead to file system corruption in non-debug builds. This seems to be reproducible with workloads of small O_DSYNC write, although so far I've not managed to come up with a with an isolated reproducer. The fix for the issue is relatively simple: tell xfs_bmapi_write that we are only asked to convert delayed allocations and skip holes in that case. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-09xfs: fix bogus minleft manipulationsChristoph Hellwig
We can't just set minleft to 0 when we're low on space - that's exactly what we need minleft for: to protect space in the AG for btree block allocations when we are low on free space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-12-07Merge branch 'xfs-4.10-misc-fixes-3' into for-nextDave Chinner
2016-12-05xfs: error out if trying to add attrs and anextents > 0Darrick J. Wong
We shouldn't assert if somehow we end up trying to add an attr fork to an inode that apparently already has attr extents because this is an indication of on-disk corruption. Instead, return an error code to userspace. 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>
2016-12-05xfs: complain if we don't get nextents bmap recordsDarrick J. Wong
When reading into memory all extents of a btree-format inode fork, complain if the number of extents we find is not the same as the number of extents reported in the inode core. This is needed to stop an IO action from accessing the garbage areas of the in-core fork. [dchinner: removed redundant assert] 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>
2016-12-05xfs: handle cow fork in xfs_bmap_trace_exlistEric Sandeen
By inspection, xfs_bmap_trace_exlist isn't handling cow forks, and will trace the data fork instead. Fix this by setting state appropriately if whichfork == XFS_COW_FORK. ()___() < @ @ > | | {o_o} (|) Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05xfs: pass state not whichfork to trace_xfs_extlistEric Sandeen
When xfs_bmap_trace_exlist called trace_xfs_extlist, it sent in the "whichfork" var instead of the bmap "state" as expected (even though state was already set up for this purpose). As a result, the xfs_bmap_class in tracing code used "whichfork" not state in xfs_iext_state_to_fork(), and got the wrong ifork pointer. It all goes downhill from there, including an ASSERT when ifp_bytes is empty by the time it reaches xfs_iext_get_ext(): XFS: Assertion failed: idx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t) Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-28Merge branch 'xfs-4.10-misc-fixes-2' into for-nextDave Chinner
2016-11-28xfs: track preallocation separately in xfs_bmapi_reserve_delalloc()Brian Foster
Speculative preallocation is currently processed entirely by the callers of xfs_bmapi_reserve_delalloc(). The caller determines how much preallocation to include, adjusts the extent length and passes down the resulting request. While this works fine for post-eof speculative preallocation, it is not as reliable for COW fork preallocation. COW fork preallocation is implemented via the cowextszhint, which aligns the start offset as well as the length of the extent. Further, it is difficult for the caller to accurately identify when preallocation occurs because the returned extent could have been merged with neighboring extents in the fork. To simplify this situation and facilitate further COW fork preallocation enhancements, update xfs_bmapi_reserve_delalloc() to take a separate preallocation parameter to incorporate into the allocation request. The preallocation blocks value is tacked onto the end of the request and adjusted to accommodate neighboring extents and extent size limits. Since xfs_bmapi_reserve_delalloc() now knows precisely how much preallocation was included in the allocation, it can also tag the inodes appropriately to support preallocation reclaim. Note that xfs_bmapi_reserve_delalloc() callers are not yet updated to use the preallocation mechanism. This patch should not change behavior outside of correctly tagging reflink inodes when start offset preallocation occurs (which the caller does not handle correctly). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-28xfs: factor rmap btree size into the indlen calculationsDarrick J. Wong
When we're estimating the amount of space it's going to take to satisfy a delalloc reservation, we need to include the space that we might need to grow the rmapbt. This helps us to avoid running out of space later when _iomap_write_allocate needs more space than we reserved. Eryu Guan observed this happening on generic/224 when sunit/swidth were set. Reported-by: Eryu Guan <eguan@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>
2016-11-24Merge branch 'xfs-4.10-extent-lookup' into for-nextDave Chinner
2016-11-24xfs: remove NULLEXTNUMChristoph Hellwig
We only ever set a field to this constant for an impossible to reach error case in xfs_bmap_search_extents. That functions has been removed, so we can remove the constant as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: remove xfs_bmap_search_extentsChristoph Hellwig
Now that all users are gone. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: remove prev argument to xfs_bmapi_reserve_delallocChristoph Hellwig
We can easily lookup the previous extent for the cases where we need it, which saves the callers from looking it up for us later in the series. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: use new extent lookup helpers in __xfs_bunmapiChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: use new extent lookup helpers in xfs_bmapi_writeChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: use new extent lookup helpers in xfs_bmapi_readChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: cleanup xfs_bmap_last_beforeChristoph Hellwig
Rewrite the function using xfs_iext_lookup_extent and xfs_iext_get_extent, and massage the flow into something easily understandable. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-10Merge branch 'xfs-4.10-misc-fixes-1' into for-nextDave Chinner
2016-11-08xfs: provide helper for counting extents from if_bytesEric Sandeen
The open-coded pattern: ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t) is all over the xfs code; provide a new helper xfs_iext_count(ifp) to count the number of inline extents in an inode fork. [dchinner: pick up several missed conversions] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-08xfs: check return value of _trans_reserve_quota_nblksDarrick J. Wong
Check the return value of xfs_trans_reserve_quota_nblks for errors. 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>
2016-10-20xfs: remove xfs_bunmapi_cowChristoph Hellwig
Since no one uses it anymore. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: refactor xfs_bunmapi_cowChristoph Hellwig
Split out two helpers for deleting delayed or real extents from the COW fork. This allows to call them directly from xfs_reflink_cow_end_io once that function is refactored to iterate the extent tree. It will also allow to reuse the delalloc deletion from xfs_bunmapi in the future. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: add xfs_trim_extentDarrick J. Wong
This helpers allows to trim an extent to a subset of it's original range while making sure the block numbers in it remain valid, In the future xfs_trim_extent and xfs_bmapi_trim_map should probably be merged in some form. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: split from a previous patch from Darrick, moved around and added support for "raw" delayed extents"] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: remove pointless error goto in xfs_bmap_remap_allocEric Sandeen
The commit: f65306ea xfs: map an inode's offset to an exact physical block added a pointless error0: target; remove it. Addresses-Coverity-Id: 1373865 Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: remove redundant assignment of ifpColin Ian King
Remove redundant ifp = ifp statement, it does nothing. Found with static analysis by CoverityScan. Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-05xfs: try other AGs to allocate a BMBT blockDarrick J. Wong
Prior to the introduction of reflink, allocating a block and mapping it into a file was performed in a single transaction with a single block reservation, and the allocator was supposed to find enough blocks to allocate the extent and any BMBT blocks that might be necessary (unless we're low on space). However, due to the way copy on write works, allocation and mapping have been split into two transactions, which means that we must be able to handle the case where we allocate an extent for CoW but that AG runs out of free space before the blocks can be mapped into a file, and the mapping requires a new BMBT block. When this happens, look in one of the other AGs for a BMBT block instead of taking the FS down. The same applies to the functions that convert a data fork to extents and later btree format. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05xfs: create a separate cow extent size hint for the allocatorDarrick J. Wong
Create a per-inode extent size allocator hint for copy-on-write. This hint is separate from the existing extent size hint so that CoW can take advantage of the fragmentation-reducing properties of extent size hints without disabling delalloc for regular writes. The extent size hint that's fed to the allocator during a copy on write operation is the greater of the cowextsize and regular extsize hint. During reflink, if we're sharing the entire source file to the entire destination file and the destination file doesn't already have a cowextsize hint, propagate the source file's cowextsize hint to the destination file. Furthermore, zero the bulkstat buffer prior to setting the fields so that we don't copy kernel memory contents into userspace. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05xfs: store in-progress CoW allocations in the refcount btreeDarrick J. Wong
Due to the way the CoW algorithm in XFS works, there's an interval during which blocks allocated to handle a CoW can be lost -- if the FS goes down after the blocks are allocated but before the block remapping takes place. This is exacerbated by the cowextsz hint -- allocated reservations can sit around for a while, waiting to get used. Since the refcount btree doesn't normally store records with refcount of 1, we can use it to record these in-progress extents. In-progress blocks cannot be shared because they're not user-visible, so there shouldn't be any conflicts with other programs. This is a better solution than holding EFIs during writeback because (a) EFIs can't be relogged currently, (b) even if they could, EFIs are bound by available log space, which puts an unnecessary upper bound on how much CoW we can have in flight, and (c) we already have a mechanism to track blocks. At mount time, read the refcount records and free anything we find with a refcount of 1 because those were in-progress when the FS went down. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05xfs: support removing extents from CoW forkDarrick J. Wong
Create a helper method to remove extents from the CoW fork without any of the side effects (rmapbt/bmbt updates) of the regular extent deletion routine. We'll eventually use this to clear out the CoW fork during ioend processing. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: support allocating delayed extents in CoW forkDarrick J. Wong
Modify xfs_bmap_add_extent_delay_real() so that we can convert delayed allocation extents in the CoW fork to real allocations, and wire this up all the way back to xfs_iomap_write_allocate(). In a subsequent patch, we'll modify the writepage handler to call this. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: support bmapping delalloc extents in the CoW forkDarrick J. Wong
Allow the creation of delayed allocation extents in the CoW fork. In a subsequent patch we'll wire up iomap_begin to actually do this via reflink helper functions. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: introduce the CoW forkDarrick J. Wong
Introduce a new in-core fork for storing copy-on-write delalloc reservations and allocated extents that are in the process of being written out. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: return work remaining at the end of a bunmapi operationDarrick J. Wong
Return the range of file blocks that bunmapi didn't free. This hint is used by CoW and reflink to figure out what part of an extent actually got freed so that it can set up the appropriate atomic remapping of just the freed range. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: implement deferred bmbt map/unmap operationsDarrick J. Wong
Implement deferred versions of the inode block map/unmap functions. These will be used in subsequent patches to make reflink operations atomic. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: pass bmapi flags through to bmap_del_extentDarrick J. Wong
Pass BMAPI_ flags from bunmapi into bmap_del_extent and extend BMAPI_REMAP (which means "don't touch the allocator or the quota accounting") to apply to bunmapi as well. This will be used to implement the unmap operation, which will be used by swapext. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04xfs: map an inode's offset to an exact physical blockDarrick J. Wong
Teach the bmap routine to know how to map a range of file blocks to a specific range of physical blocks, instead of simply allocating fresh blocks. This enables reflink to map a file to blocks that are already in use. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: adjust refcount when unmapping file blocksDarrick J. Wong
When we're unmapping blocks from a reflinked file, decrease the refcount of the affected blocks and free the extents that are no longer in use. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03Merge branch 'xfs-4.9-log-recovery-fixes' into for-nextxfs-for-linus-4.9-rc1Dave Chinner
2016-10-03Merge branch 'xfs-4.9-delalloc-rework' into for-nextDave Chinner
2016-09-26xfs: remote attribute blocks aren't really userdataDave Chinner
When adding a new remote attribute, we write the attribute to the new extent before the allocation transaction is committed. This means we cannot reuse busy extents as that violates crash consistency semantics. Hence we currently treat remote attribute extent allocation like userdata because it has the same overwrite ordering constraints as userdata. Unfortunately, this also allows the allocator to incorrectly apply extent size hints to the remote attribute extent allocation. This results in interesting failures, such as transaction block reservation overruns and in-memory inode attribute fork corruption. To fix this, we need to separate the busy extent reuse configuration from the userdata configuration. This changes the definition of XFS_BMAPI_METADATA slightly - it now means that allocation is metadata and reuse of busy extents is acceptible due to the metadata ordering semantics of the journal. If this flag is not set, it means the allocation is that has unordered data writeback, and hence busy extent reuse is not allowed. It no longer implies the allocation is for user data, just that the data write will not be strictly ordered. This matches the semantics for both user data and remote attribute block allocation. As such, This patch changes the "userdata" field to a "datatype" field, and adds a "no busy reuse" flag to the field. When we detect an unordered data extent allocation, we immediately set the no reuse flag. We then set the "user data" flags based on the inode fork we are allocating the extent to. Hence we only set userdata flags on data fork allocations now and consider attribute fork remote extents to be an unordered metadata extent. The result is that remote attribute extents now have the expected allocation semantics, and the data fork allocation behaviour is completely unchanged. It should be noted that there may be other ways to fix this (e.g. use ordered metadata buffers for the remote attribute extent data write) but they are more invasive and difficult to validate both from a design and implementation POV. Hence this patch takes the simple, obvious route to fixing the problem... Reported-and-tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19xfs: rewrite and optimize the delalloc write pathChristoph Hellwig
Currently xfs_iomap_write_delay does up to lookups in the inode extent tree, which is rather costly especially with the new iomap based write path and small write sizes. But it turns out that the low-level xfs_bmap_search_extents gives us all the information we need in the regular delalloc buffered write path: - it will return us an extent covering the block we are looking up if it exists. In that case we can simply return that extent to the caller and are done - it will tell us if we are beyoned the last current allocated block with an eof return parameter. In that case we can create a delalloc reservation and use the also returned information about the last extent in the file as the hint to size our delalloc reservation. - it can tell us that we are writing into a hole, but that there is an extent beyoned this hole. In this case we can create a delalloc reservation that covers the requested size (possible capped to the next existing allocation). All that can be done in one single routine instead of bouncing up and down a few layers. This reduced the CPU overhead of the block mapping routines and also simplified the code a lot. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19xfs: set up per-AG free space reservationsDarrick J. Wong
One unfortunate quirk of the reference count and reverse mapping btrees -- they can expand in size when blocks are written to *other* allocation groups if, say, one large extent becomes a lot of tiny extents. Since we don't want to start throwing errors in the middle of CoWing, we need to reserve some blocks to handle future expansion. The transaction block reservation counters aren't sufficient here because we have to have a reserve of blocks in every AG, not just somewhere in the filesystem. Therefore, create two per-AG block reservation pools. One feeds the AGFL so that rmapbt expansion always succeeds, and the other feeds all other metadata so that refcountbt expansion never fails. Use the count of how many reserved blocks we need to have on hand to create a virtual reservation in the AG. Through selective clamping of the maximum length of allocation requests and of the length of the longest free extent, we can make it look like there's less free space in the AG unless the reservation owner is asking for blocks. In other words, play some accounting tricks in-core to make sure that we always have blocks available. On the plus side, there's nothing to clean up if we crash, which is contrast to the strategy that the rough draft used (actually removing extents from the freespace btrees). 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>
2016-08-03xfs: propagate bmap updates to rmapbtDarrick J. Wong
When we map, unmap, or convert an extent in a file's data or attr fork, schedule a respective update in the rmapbt. Previous versions of this patch required a 1:1 correspondence between bmap and rmap, but this is no longer true as we now have ability to make interval queries against the rmapbt. We use the deferred operations code to handle redo operations atomically and deadlock free. This plumbs in all five rmap actions (map, unmap, convert extent, alloc, free); we'll use the first three now for file data, and reflink will want the last two. We also add an error injection site to test log recovery. Finally, we need to fix the bmap shift extent code to adjust the rmaps correctly. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03xfs: rmap btree requires more reserved free spaceDarrick J. Wong
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>
2016-08-03xfs: add owner field to extent allocation and freeingDarrick J. Wong
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>