- 07 Apr, 2014 5 commits
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Josef Bacik authored
We currently rely too heavily on roots being read-only to save us from just accessing root->commit_root. We can easily balance blocks out from underneath a read only root, so to save us from getting screwed make sure we only access root->commit_root under the commit root sem. Thanks, Signed-off-by:
Josef Bacik <jbacik@fb.com> Signed-off-by:
Chris Mason <clm@fb.com>
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Josef Bacik authored
Lets try this again. We can deadlock the box if we send on a box and try to write onto the same fs with the app that is trying to listen to the send pipe. This is because the writer could get stuck waiting for a transaction commit which is being blocked by the send. So fix this by making sure looking at the commit roots is always going to be consistent. We do this by keeping track of which roots need to have their commit roots swapped during commit, and then taking the commit_root_sem and swapping them all at once. Then make sure we take a read lock on the commit_root_sem in cases where we search the commit root to make sure we're always looking at a consistent view of the commit roots. Previously we had problems with this because we would swap a fs tree commit root and then swap the extent tree commit root independently which would cause the backref walking code to screw up sometimes. With this patch we no longer deadlock and pass all the weird send/receive corner cases. Thanks, Reportedy-by:
Hugo Mills <hugo@carfax.org.uk> Signed-off-by:
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Josef Bacik authored
So I have an awful exercise script that will run snapshot, balance and send/receive in parallel. This sometimes would crash spectacularly and when it came back up the fs would be completely hosed. Turns out this is because of a bad interaction of balance and send/receive. Send will hold onto its entire path for the whole send, but its blocks could get relocated out from underneath it, and because it doesn't old tree locks theres nothing to keep this from happening. So it will go to read in a slot with an old transid, and we could have re-allocated this block for something else and it could have a completely different transid. But because we think it is invalid we clear uptodate and re-read in the block. If we do this before we actually write out the new block we could write back stale data to the fs, and boom we're screwed. Now we definitely need to fix this disconnect between send and balance, but we really really need to not allow ourselves to accidently read in stale data over new data. So make sure we check if the extent buffer is not under io before clearing uptodate, this will kick back EIO to the caller instead of reading in stale data and keep us from corrupting the fs. Thanks, Signed-off-by:
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Josef Bacik authored
We could have possibly added an extent_op to the locked_ref while we dropped locked_ref->lock, so check for this case as well and loop around. Otherwise we could lose flag updates which would lead to extent tree corruption. Thanks, cc: stable@vger.kernel.org Signed-off-by:
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Josef Bacik authored
This was done to allow NO_COW to continue to be NO_COW after relocation but it is not right. When relocating we will convert blocks to FULL_BACKREF that we relocate. We can leave some of these full backref blocks behind if they are not cow'ed out during the relocation, like if we fail the relocation with ENOSPC and then just drop the reloc tree. Then when we go to cow the block again we won't lookup the extent flags because we won't think there has been a snapshot recently which means we will do our normal ref drop thing instead of adding back a tree ref and dropping the shared ref. This will cause btrfs_free_extent to blow up because it can't find the ref we are trying to free. This was found with my ref verifying tool. Thanks, Signed-off-by:
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- 22 Mar, 2014 1 commit
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Liu Bo authored
xfstests's btrfs/035 triggers a BUG_ON, which we use to detect the split of inline extents in __btrfs_drop_extents(). For inline extents, we cannot duplicate another EXTENT_DATA item, because it breaks the rule of inline extents, that is, 'start offset' needs to be 0. We have set limitations for the source inode's compressed inline extents, because it needs to decompress and recompress. Now the destination inode's inline extents also need similar limitations. With this, xfstests btrfs/035 doesn't run into panic. Signed-off-by:
Liu Bo <bo.li.liu@oracle.com> Signed-off-by:
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- 21 Mar, 2014 12 commits
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Chris Mason authored
fs/btrfs/send.c:2926: warning: ‘entry’ may be used uninitialized in this function Signed-off-by: -
Josef Bacik authored
I added an optimization for large files where we would stop searching for backrefs once we had looked at the number of references we currently had for this extent. This works great most of the time, but for snapshots that point to this extent and has changes in the original root this assumption falls on it face. So keep track of any delayed ref mods made and add in the actual ref count as reported by the extent item and use that to limit how far down an inode we'll search for extents. Thanks, Reportedy-by:
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Filipe Manana authored
For an incremental send, fix the process of determining whether the directory inode we're currently processing needs to have its move/rename operation delayed. We were ignoring the fact that if the inode's new immediate ancestor has a higher inode number than ours but wasn't renamed/moved, we might still need to delay our move/rename, because some other ancestor directory higher in the hierarchy might have an inode number higher than ours *and* was renamed/moved too - in this case we have to wait for rename/move of that ancestor to happen before our current directory's rename/move operation. Simple steps to reproduce this issue: $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir -p /mnt/a/x1/x2 $ mkdir /mnt/a/Z $ mkdir -p /mnt/a/x1/x2/x3/x4/x5 $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mv /mnt/a/x1/x2/x3 /mnt/a/Z/X33 $ mv /mnt/a/x1/x2 /mnt/a/Z/X33/x4/x5/X22 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send The incremental send caused the kernel code to enter an infinite loop when building the path string for directory Z after its references are processed. A more complex scenario: $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir -p /mnt/a/b/c/d $ mkdir /mnt/a/b/c/d/e $ mkdir /mnt/a/b/c/d/f $ mv /mnt/a/b/c/d/e /mnt/a/b/c/d/f/E2 $ mkdir /mmt/a/b/c/g $ mv /mnt/a/b/c/d /mnt/a/b/D2 $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mkdir /mnt/a/o $ mv /mnt/a/b/c/g /mnt/a/b/D2/f/G2 $ mv /mnt/a/b/D2 /mnt/a/b/dd $ mv /mnt/a/b/c /mnt/a/C2 $ mv /mnt/a/b/dd/f /mnt/a/o/FF $ mv /mnt/a/b /mnt/a/o/FF/E2/BB $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send A test case for xfstests follows. Signed-off-by:Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by:
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Filipe Manana authored
It's possible to change the parent/child relationship between directories in such a way that if a child directory has a higher inode number than its parent, it doesn't necessarily means the child rename/move operation can be performed immediately. The parent migth have its own rename/move operation delayed, therefore in this case the child needs to have its rename/move operation delayed too, and be performed after its new parent's rename/move. Steps to reproduce the issue: $ umount /mnt $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/C $ mv /mnt/C /mnt/A $ mv /mnt/B /mnt/A/C $ mkdir /mnt/A/C/D $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mv /mnt/A/C/D /mnt/A/D2 $ mv /mnt/A/C/B /mnt/A/D2/B2 $ mv /mnt/A/C /mnt/A/D2/B2/C2 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send The incremental send caused the kernel code to enter an infinite loop when building the path string for directory C after its references are processed. The necessary conditions here are that C has an inode number higher than both A and B, and B as an higher inode number higher than A, and D has the highest inode number, that is: inode_number(A) < inode_number(B) < inode_number(C) < inode_number(D) The same issue could happen if after the first snapshot there's any number of intermediary parent directories between A2 and B2, and between B2 and C2. A test case for xfstests follows, covering this simple case and more advanced ones, with files and hard links created inside the directories. Signed-off-by: -
Filipe Manana authored
No need to search in the send tree for the generation number of the inode, we already have it in the recorded_ref structure passed to us. Signed-off-by:
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Filipe Manana authored
While we update an existing ref head's extent_op, we're not holding its spinlock, so while we're updating its extent_op contents (key, flags) we can have a task running __btrfs_run_delayed_refs() that holds the ref head's lock and sets its extent_op to NULL right after the task updating the ref head just checked its extent_op was not NULL. Signed-off-by:
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Qu Wenruo authored
Since most of the btrfs_workqueue is printed as pointer address, for easier analysis, add trace for btrfs_workqueue alloc/destroy. So it is possible to determine the workqueue that a given work belongs to(by comparing the wq pointer address with alloc trace event). Signed-off-by:
Qu Wenruo <quenruo@cn.fujitsu.com> Signed-off-by:
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Filipe Manana authored
When finding new extents during an autodefrag, don't do so many fs tree lookups to find an extent with a size smaller then the target treshold. Instead, after each fs tree forward search immediately unlock upper levels and process the entire leaf while holding a read lock on the leaf, since our leaf processing is very fast. This reduces lock contention, allowing for higher concurrency when other tasks want to write/update items related to other inodes in the fs tree, as we're not holding read locks on upper tree levels while processing the leaf and we do less tree searches. Test: sysbench --test=fileio --file-num=512 --file-total-size=16G \ --file-test-mode=rndrw --num-threads=32 --file-block-size=32768 \ --file-rw-ratio=3 --file-io-mode=sync --max-time=1800 \ --max-requests=10000000000 [prepare|run] (fileystem mounted with -o autodefrag, averages of 5 runs) Before this change: 58.852Mb/sec throughtput, read 77.589Gb, written 25.863Gb After this change: 63.034Mb/sec throughtput, read 83.102Gb, written 27.701Gb Test machine: quad core intel i5-3570K, 32Gb of RAM, SSD. Signed-off-by: -
Guangyu Sun authored
The error message is confusing: # btrfs sub delete /mnt/mysub/ Delete subvolume '/mnt/mysub' ERROR: cannot delete '/mnt/mysub' - Directory not empty The error message does not make sense to me: It's not about deleting a directory but it's a subvolume, and it doesn't matter if the subvolume is empty or not. Maybe EPERM or is more appropriate in this case, combined with an explanatory kernel log message. (e.g. "subvolume with ID 123 cannot be deleted because it is configured as default subvolume.") Reported-by:
Koen De Wit <koen.de.wit@oracle.com> Signed-off-by:
Guangyu Sun <guangyu.sun@oracle.com> Reviewed-by:
David Sterba <dsterba@suse.cz> Signed-off-by:
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Filipe Manana authored
Signed-off-by:
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Filipe Manana authored
When locking file ranges in the inode's io_tree, cache the first extent state that belongs to the target range, so that when unlocking the range we don't need to search in the io_tree again, reducing cpu time and making and therefore holding the io_tree's lock for a shorter period. Signed-off-by:
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Josef Bacik authored
Zach found this deadlock that would happen like this btrfs_end_transaction <- reduce trans->use_count to 0 btrfs_run_delayed_refs btrfs_cow_block find_free_extent btrfs_start_transaction <- increase trans->use_count to 1 allocate chunk btrfs_end_transaction <- decrease trans->use_count to 0 btrfs_run_delayed_refs lock tree block we are cowing above ^^ We need to only decrease trans->use_count if it is above 1, otherwise leave it alone. This will make nested trans be the only ones who decrease their added ref, and will let us get rid of the trans->use_count++ hack if we have to commit the transaction. Thanks, cc: stable@vger.kernel.org Reported-by:Zach Brown <zab@redhat.com> Signed-off-by:
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- 10 Mar, 2014 22 commits
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Miao Xie authored
We didn't have a lock to protect the access to the delalloc inodes list, that is we might access a empty delalloc inodes list if someone start flushing delalloc inodes because the delalloc inodes were moved into a other list temporarily. Fix it by wrapping the access with a lock. Signed-off-by:
Miao Xie <miaox@cn.fujitsu.com> Signed-off-by:
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Miao Xie authored
When we create a snapshot, we just need wait the ordered extents in the source fs/file root, but because we use the global mutex to protect this ordered extents list of the source fs/file root to avoid accessing a empty list, if someone got the mutex to access the ordered extents list of the other fs/file root, we had to wait. This patch splits the above global mutex, now every fs/file root has its own mutex to protect its own list. Signed-off-by:
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Miao Xie authored
We needn't flush all delalloc inodes when we doesn't get s_umount lock, or we would make the tasks wait for a long time. Signed-off-by:
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Miao Xie authored
generic/074 in xfstests failed sometimes because of the enospc error, the reason of this problem is that we just reclaimed the space we need from the reserved space for delalloc, and then tried to reserve the space, but if some task did no-flush reservation between the above reclamation and reservation, Task1 Task2 shrink_delalloc() reclaim 1 block (The space that can be reserved now is 1 block) do no-flush reservation reserve 1 block (The space that can be reserved now is 0 block) reserving 1 block failed the reservation of Task1 failed, but in fact, there was enough space to reserve if we could reclaim more space before. Fix this problem by the aggressive reclamation of the reserved delalloc metadata space. Signed-off-by:
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Miao Xie authored
The reason is: - The per-cpu counter has its own lock to protect itself. - Here we needn't get a exact value. Signed-off-by:
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Miao Xie authored
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Miao Xie authored
As the comment in the btrfs_direct_IO says, only the compressed pages need be flush again to make sure they are on the disk, but the common pages needn't, so we add a if statement to check if the inode has compressed pages or not, if no, skip the flush. And in order to prevent the write ranges from intersecting, we need wait for the running ordered extents. But the current code waits for them twice, one is done before the direct IO starts (in btrfs_wait_ordered_range()), the other is before we get the blocks, it is unnecessary. because we can do the direct IO without holding i_mutex, it means that the intersected ordered extents may happen during the direct IO, the first wait can not avoid this problem. So we use filemap_fdatawrite_range() instead of btrfs_wait_ordered_range() to remove the first wait. Signed-off-by:
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Miao Xie authored
The tasks that wait for the IO_DONE flag just care about the io of the dirty pages, so it is better to wake up them immediately after all the pages are written, not the whole process of the io completes. Signed-off-by:
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Miao Xie authored
btrfs_wait_ordered_roots() moves all the list entries to a new list, and then deals with them one by one. But if the other task invokes this function at that time, it would get a empty list. It makes the enospc error happens more early. Fix it. Signed-off-by:
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Miao Xie authored
If the snapshot creation happened after the nocow write but before the dirty data flush, we would fail to flush the dirty data because of no space. So we must keep track of when those nocow write operations start and when they end, if there are nocow writers, the snapshot creators must wait. In order to implement this function, I introduce btrfs_{start, end}_nocow_write(), which is similar to mnt_{want,drop}_write(). These two functions are only used for nocow file write operations. Signed-off-by: -
Qu Wenruo authored
Add ftrace for btrfs_workqueue for further workqueue tunning. This patch needs to applied after the workqueue replace patchset. Signed-off-by:
Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by:
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Qu Wenruo authored
The new btrfs_workqueue still use open-coded function defition, this patch will change them into btrfs_func_t type which is much the same as kernel workqueue. Signed-off-by:
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Liu Bo authored
Btrfs send reads data from disk and then writes to a stream via pipe or a file via flush. Currently we're going to read each page a time, so every page results in a disk read, which is not friendly to disks, esp. HDD. Given that, the performance can be gained by adding readahead for those pages. Here is a quick test: $ btrfs subvolume create send $ xfs_io -f -c "pwrite 0 1G" send/foobar $ btrfs subvolume snap -r send ro $ time "btrfs send ro -f /dev/null" w/o w real 1m37.527s 0m9.097s user 0m0.122s 0m0.086s sys 0m53.191s 0m12.857s Signed-off-by: -
Liu Bo authored
This has no functional change, only picks out the same part of two functions, and makes it shared. Signed-off-by:
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Filipe Manana authored
When we're finishing processing of an inode, if we're dealing with a directory inode that has a pending move/rename operation, we don't need to send a utimes update instruction to the send stream, as we'll do it later after doing the move/rename operation. Therefore we save some time here building paths and doing btree lookups. Signed-off-by:
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Filipe Manana authored
When using prealloc extents, a file defragment operation may actually fragment the file and increase the amount of data space used by the file. This change fixes that behaviour. Example: $ mkfs.btrfs -f /dev/sdb3 $ mount /dev/sdb3 /mnt $ cd /mnt $ xfs_io -f -c 'falloc 0 1048576' foobar && sync $ xfs_io -c 'pwrite -S 0xff -b 100000 5000 100000' foobar $ xfs_io -c 'pwrite -S 0xac -b 100000 200000 100000' foobar $ xfs_io -c 'pwrite -S 0xe1 -b 100000 900000 100000' foobar && sync Before defragmenting the file: $ btrfs filesystem df /mnt Data, single: total=8.00MiB, used=1.25MiB System, DUP: total=8.00MiB, used=16.00KiB System, single: total=4.00MiB, used=0.00 Metadata, DUP: total=1.00GiB, used=112.00KiB Metadata, single: total=8.00MiB, used=0.00 $ btrfs-debug-tree /dev/sdb3 (...) item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53 prealloc data disk byte 12845056 nr 1048576 prealloc data offset 0 nr 4096 item 7 key (257 EXTENT_DATA 4096) itemoff 15757 itemsize 53 extent data disk byte 12845056 nr 1048576 extent data offset 4096 nr 102400 ram 1048576 extent compression 0 item 8 key (257 EXTENT_DATA 106496) itemoff 15704 itemsize 53 prealloc data disk byte 12845056 nr 1048576 prealloc data offset 106496 nr 90112 item 9 key (257 EXTENT_DATA 196608) itemoff 15651 itemsize 53 extent data disk byte 12845056 nr 1048576 extent data offset 196608 nr 106496 ram 1048576 extent compression 0 item 10 key (257 EXTENT_DATA 303104) itemoff 15598 itemsize 53 prealloc data disk byte 12845056 nr 1048576 prealloc data offset 303104 nr 593920 item 11 key (257 EXTENT_DATA 897024) itemoff 15545 itemsize 53 extent data disk byte 12845056 nr 1048576 extent data offset 897024 nr 106496 ram 1048576 extent compression 0 item 12 key (257 EXTENT_DATA 1003520) itemoff 15492 itemsize 53 prealloc data disk byte 12845056 nr 1048576 prealloc data offset 1003520 nr 45056 (...) Now defragmenting the file results in more data space used than before: $ btrfs filesystem defragment -f foobar && sync $ btrfs filesystem df /mnt Data, single: total=8.00MiB, used=1.55MiB System, DUP: total=8.00MiB, used=16.00KiB System, single: total=4.00MiB, used=0.00 Metadata, DUP: total=1.00GiB, used=112.00KiB Metadata, single: total=8.00MiB, used=0.00 And the corresponding file extent items are now no longer perfectly sequential as before, and we're now needlessly using more space from data block groups: $ btrfs-debug-tree /dev/sdb3 (...) item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53 extent data disk byte 12845056 nr 1048576 extent data offset 0 nr 4096 ram 1048576 extent compression 0 item 7 key (257 EXTENT_DATA 4096) itemoff 15757 itemsize 53 extent data disk byte 13893632 nr 102400 extent data offset 0 nr 102400 ram 102400 extent compression 0 item 8 key (257 EXTENT_DATA 106496) itemoff 15704 itemsize 53 extent data disk byte 12845056 nr 1048576 extent data offset 106496 nr 90112 ram 1048576 extent compression 0 item 9 key (257 EXTENT_DATA 196608) itemoff 15651 itemsize 53 extent data disk byte 13996032 nr 106496 extent data offset 0 nr 106496 ram 106496 extent compression 0 item 10 key (257 EXTENT_DATA 303104) itemoff 15598 itemsize 53 prealloc data disk byte 12845056 nr 1048576 prealloc data offset 303104 nr 593920 item 11 key (257 EXTENT_DATA 897024) itemoff 15545 itemsize 53 extent data disk byte 14102528 nr 106496 extent data offset 0 nr 106496 ram 106496 extent compression 0 item 12 key (257 EXTENT_DATA 1003520) itemoff 15492 itemsize 53 extent data disk byte 12845056 nr 1048576 extent data offset 1003520 nr 45056 ram 1048576 extent compression 0 (...) With this change, the above example will no longer cause allocation of new data space nor change the sequentiality of the file extents, that is, defragment will be effectless, leaving all extent items pointing to the extent starting at disk byte 12845056. In a 20Gb filesystem I had, mounted with the autodefrag option and 20 files of 400Mb each, initially consisting of a single prealloc extent of 400Mb, having random writes happening at a low rate, lead to a total of over ~17Gb of data space used, not far from eventually reaching an ENOSPC state. Signed-off-by:
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Filipe Manana authored
When the defrag flag BTRFS_DEFRAG_RANGE_START_IO is set and compression enabled, we weren't flushing completely, as writing compressed extents is a 2 steps process, one to compress the data and another one to write the compressed data to disk. Signed-off-by:
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Qu Wenruo authored
Since the "_struct" suffix is mainly used for distinguish the differnt btrfs_work between the original and the newly created one, there is no need using the suffix since all btrfs_workers are changed into btrfs_workqueue. Also this patch fixed some codes whose code style is changed due to the too long "_struct" suffix. Signed-off-by:
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Qu Wenruo authored
Since all the btrfs_worker is replaced with the newly created btrfs_workqueue, the old codes can be easily remove. Signed-off-by:
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Qu Wenruo authored
Replace the fs_info->scrub_* with the newly created btrfs_workqueue. Signed-off-by:
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Qu Wenruo authored
Replace the fs_info->qgroup_rescan_worker with the newly created btrfs_workqueue. Signed-off-by:
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Qu Wenruo authored
Replace the fs_info->delayed_workers with the newly created btrfs_workqueue. Signed-off-by:
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