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path: root/fs/xfs/xfs_extfree_item.h
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2016-08-03xfs: refactor redo intent item processingDarrick J. Wong
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>
2015-08-19xfs: fix efi/efd error handling to avoid fs shutdown hangsBrian Foster
Freeing an extent in XFS involves logging an EFI (extent free intention), freeing the actual extent, and logging an EFD (extent free done). The EFI object is created with a reference count of 2: one for the current transaction and one for the subsequently created EFD. Under normal circumstances, the first reference is dropped when the EFI is unpinned and the second reference is dropped when the EFD is committed to the on-disk log. In event of errors or filesystem shutdown, there are various potential cleanup scenarios depending on the state of the EFI/EFD. The cleanup scenarios are confusing and racy, as demonstrated by the following test sequence: # mount $dev $mnt # fsstress -d $mnt -n 99999 -p 16 -z -f fallocate=1 \ -f punch=1 -f creat=1 -f unlink=1 & # sleep 5 # killall -9 fsstress; wait # godown -f $mnt # umount ... in which the final umount can hang due to the AIL being pinned indefinitely by one or more EFI items. This can occur due to several conditions. For example, if the shutdown occurs after the EFI is committed to the on-disk log and the EFD committed to the CIL, but before the EFD committed to the log, the EFD iop_committed() abort handler does not drop its reference to the EFI. Alternatively, manual error injection in the xfs_bmap_finish() codepath shows that if an error occurs after the EFI transaction is committed but before the EFD is constructed and logged, the EFI is never released from the AIL. Update the EFI/EFD item handling code to use a more straightforward and reliable approach to error handling. If an error occurs after the EFI transaction is committed and before the EFD is constructed, release the EFI explicitly from xfs_bmap_finish(). If the EFI transaction is cancelled, release the EFI in the unlock handler. Once the EFD is constructed, it is responsible for releasing the EFI under any circumstances (including whether the EFI item aborts due to log I/O error). Update the EFD item handlers to release the EFI if the transaction is cancelled or aborts due to log I/O error. Finally, update xfs_bmap_finish() to log at least one EFD extent to the transaction before xfs_free_extent() errors are handled to ensure the transaction is dirty and EFD item error handling is triggered. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19xfs: disentagle EFI release from the extent countBrian Foster
Release of the EFI either occurs based on the reference count or the extent count. The extent count used is either the count tracked in the EFI or EFD, depending on the particular situation. In either case, the count is initialized to the final value and thus always matches the current efi_next_extent value once the EFI is completely constructed. For example, the EFI extent count is increased as the extents are logged in xfs_bmap_finish() and the full free list is always completely processed. Therefore, the count is guaranteed to be complete once the EFI transaction is committed. The EFD uses the efd_nextents counter to release the EFI. This counter is initialized to the count of the EFI when the EFD is created. Thus the EFD, as currently used, has no concept of partial EFI release based on extent count. Given that the EFI extent count is always released in whole, use of the extent count for reference counting is unnecessary. Remove this level of the API and release the EFI based on the core reference count. The efi_next_extent counter remains because it is still used to track the slot to log the next extent to free. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2013-08-12xfs: split out EFI/EFD log item format definitionDave Chinner
The EFI/EFD item format definitions are shared with userspace. Split the out of header files that contain kernel only defintions to make it simple to shared them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-05xfs: don't free EFIs before the EFDs are committedDave Chinner
Filesystems are occasionally being shut down with this error: xfs_trans_ail_delete_bulk: attempting to delete a log item that is not in the AIL. It was diagnosed to be related to the EFI/EFD commit order when the EFI and EFD are in different checkpoints and the EFD is committed before the EFI here: http://oss.sgi.com/archives/xfs/2013-01/msg00082.html The real problem is that a single bit cannot fully describe the states that the EFI/EFD processing can be in. These completion states are: EFI EFI in AIL EFD Result committed/unpinned Yes committed OK committed/pinned No committed Shutdown uncommitted No committed Shutdown Note that the "result" field is what should happen, not what does happen. The current logic is broken and handles the first two cases correctly by luck. That is, the code will free the EFI if the XFS_EFI_COMMITTED bit is *not* set, rather than if it is set. The inverted logic "works" because if both EFI and EFD are committed, then the first __xfs_efi_release() call clears the XFS_EFI_COMMITTED bit, and the second frees the EFI item. Hence as long as xfs_efi_item_committed() has been called, everything appears to be fine. It is the third case where the logic fails - where xfs_efd_item_committed() is called before xfs_efi_item_committed(), and that results in the EFI being freed before it has been committed. That is the bug that triggered the shutdown, and hence keeping track of whether the EFI has been committed or not is insufficient to correctly order the EFI/EFD operations w.r.t. the AIL. What we really want is this: the EFI is always placed into the AIL before the last reference goes away. The only way to guarantee that is that the EFI is not freed until after it has been unpinned *and* the EFD has been committed. That is, restructure the logic so that the only case that can occur is the first case. This can be done easily by replacing the XFS_EFI_COMMITTED with an EFI reference count. The EFI is initialised with it's own count, and that is not released until it is unpinned. However, there is a complication to this method - the high level EFI/EFD code in xfs_bmap_finish() does not hold direct references to the EFI structure, and runs a transaction commit between the EFI and EFD processing. Hence the EFI can be freed even before the EFD is created using such a method. Further, log recovery uses the AIL for tracking EFI/EFDs that need to be recovered, but it uses the AIL *differently* to the EFI transaction commit. Hence log recovery never pins or unpins EFIs, so we can't drop the EFI reference count indirectly to free the EFI. However, this doesn't prevent us from using a reference count here. There is a 1:1 relationship between EFIs and EFDs, so when we initialise the EFI we can take a reference count for the EFD as well. This solves the xfs_bmap_finish() issue - the EFI will never be freed until the EFD is processed. In terms of log recovery, during the committing of the EFD we can look for the XFS_EFI_RECOVERED bit being set and drop the EFI reference as well, thereby ensuring everything works correctly there as well. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2010-12-20xfs: Pull EFI/EFD handling out from under the AIL lockDave Chinner
EFI/EFD interactions are protected from races by the AIL lock. They are the only type of log items that require the the AIL lock to serialise internal state, so they need to be separated from the AIL lock before we can do bulk insert operations on the AIL. To acheive this, convert the counter of the number of extents in the EFI to an atomic so it can be safely manipulated by EFD processing without locks. Also, convert the EFI state flag manipulations to use atomic bit operations so no locks are needed to record state changes. Finally, use the state bits to determine when it is safe to free the EFI and clean up the code to do this neatly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: fix EFI transaction cancellation.Dave Chinner
XFS_EFI_CANCELED has not been set in the code base since xfs_efi_cancel() was removed back in 2006 by commit 065d312e15902976d256ddaf396a7950ec0350a8 ("[XFS] Remove unused iop_abort log item operation), and even then xfs_efi_cancel() was never called. I haven't tracked it back further than that (beyond git history), but it indicates that the handling of EFIs in cancelled transactions has been broken for a long time. Basically, when we get an IOP_UNPIN(lip, 1); call from xfs_trans_uncommit() (i.e. remove == 1), if we don't free the log item descriptor we leak it. Fix the behviour to be correct and kill the XFS_EFI_CANCELED flag. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2009-01-22[XFS] remove always-true #ifndef HAVE_FORMAT32 testsEric Sandeen
There are several tests for #ifndef HAVE_FORMAT32, but this is never defined anywhere so it is always the default behavior; just remove the ifndef goop. Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Reviewed-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2006-09-28[XFS] cleanup the field types of some item format structuresTim Shimmin
SGI-PV: 954365 SGI-Modid: xfs-linux-melb:xfs-kern:26406a Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-06-09[XFS] inode items and EFI/EFDs have different ondisk format for 32bit andTim Shimmin
64bit kernels allow recovery to handle both versions and do the necessary decoding SGI-PV: 952214 SGI-Modid: xfs-linux-melb:xfs-kern:26011a Signed-off-by: Tim Shimmin <tes@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Update license/copyright notices to match the prefered SGINathan Scott
boilerplate. SGI-PV: 913862 SGI-Modid: xfs-linux:xfs-kern:23903a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-06-21[XFS] consolidate extent item freeingChristoph Hellwig
SGI-PV: 938062 SGI-Modid: xfs-linux:xfs-kern:194415a Signed-off-by: Christoph Hellwig <hch@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!