- 08 Feb, 2021 40 commits
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Josef Bacik authored
The fix 361048f5 ("Btrfs: fix full backref problem when inserting shared block reference") added a delayed ref flushing at subvolume creation time in order to avoid hitting this particular BUG_ON(). Before this fix, we were tripping the BUG_ON() by 1. Modify snapshot A, which creates blocks with a normal reference for snapshot A, as A is the owner of these blocks. We now have delayed refs for these blocks. 2. Create a snapshot of A named B, which pushes references for the children blocks of the root node for the new root B, thus creating more delayed refs for newly allocated blocks. 3. A is modified, and because the metadata blocks can now be shared, it must push FULL_BACKREF references to the children of any block that A COWs down it's path to its target key. 4. Delayed refs are run. Because these are newly allocated blocks, we have ->must_insert_reserved reserved set on the delayed ref head, we call into alloc_reserved_tree_block() to add the extent item, and then add our ref. At the time of this fix, we were ordering FULL_BACKREF delayed ref operations first, so we'd go to add this reference and then BUG_ON() because we didn't have the FULL_BACKREF flag set. The patch fixed this problem by making sure we ran the delayed refs before we had the chance to modify A. This meant that any *new* blocks would have had their extent items created _before_ we would ever actually COW down and generate FULL_BACKREF entries. Thus the problem went away. However this BUG_ON() is actually completely bogus. The existence of a full backref doesn't necessarily mean that FULL_BACKREF must be set on that block, it must only be set on the actual parent itself. Consider the example provided above. If we COW down one path from A, any nodes are going to have a FULL_BACKREF ref pushed down to _all_ of their children, but not all of the children are going to have FULL_BACKREF set. It is completely valid to have an extent item with normal and full backrefs without FULL_BACKREF actually set on the block itself. As a final note, I have been testing with the patch (applied after this one) btrfs: stop running all delayed refs during snapshot which removed this flushing. My test was a torture test which did a lot of operations while snapshotting and deleting snapshots as well as relocation, and I never tripped this BUG_ON(). This is actually because at the time of 361048f5, we ordered SHARED keys _before_ normal references, and thus they would get run first. However currently they are ordered _after_ normal references, so we'd do the initial creation without having a shared reference, and thus not hit this BUG_ON(), which explains why I didn't start hitting this problem during my testing with my other patch applied. Signed-off-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Josef Bacik authored
The commit d6726335 ("btrfs: qgroup: Make snapshot accounting work with new extent-oriented qgroup.") added a flush of the delayed refs during snapshot creation in order to get the qgroup accounting properly. However this code has changed and been moved to it's own helper that is skipped if qgroups are turned off. Move the flushing to the helper, as we do not need it when qgroups are turned off. Also add a comment explaining why it exists, and why it doesn't actually save us. This will be helpful later when we try to fix qgroup accounting properly. Signed-off-by:
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Josef Bacik authored
We try to pre-flush the delayed refs when committing, because we want to do as little work as possible in the critical section of the transaction commit. However doing this twice can lead to very long transaction commit delays as other threads are allowed to continue to generate more delayed refs, which potentially delays the commit by multiple minutes in very extreme cases. So simply stick to one pre-flush, and then continue the rest of the transaction commit. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
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Josef Bacik authored
Previously our delayed ref running used the total number of items as the items to run. However we changed that to number of heads to run with the delayed_refs_rsv, as generally we want to run all of the operations for one bytenr. But with btrfs_run_delayed_refs(trans, 0) we set our count to 2x the number of items that we have. This is generally fine, but if we have some operation generation loads of delayed refs while we're doing this pre-flushing in the transaction commit, we'll just spin forever doing delayed refs. Fix this to simply pick the number of delayed refs we currently have, that way we do not end up doing a lot of extra work that's being generated in other threads. Reviewed-by:
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Josef Bacik authored
I've been running a stress test that runs 20 workers in their own subvolume, which are running an fsstress instance with 4 threads per worker, which is 80 total fsstress threads. In addition to this I'm running balance in the background as well as creating and deleting snapshots. This test takes around 12 hours to run normally, going slower and slower as the test goes on. The reason for this is because fsstress is running fsync sometimes, and because we're messing with block groups we often fall through to btrfs_commit_transaction, so will often have 20-30 threads all calling btrfs_commit_transaction at the same time. These all get stuck contending on the extent tree while they try to run delayed refs during the initial part of the commit. This is suboptimal, really because the extent tree is a single point of failure we only want one thread acting on that tree at once to reduce lock contention. Fix this by making the flushing mechanism a bit operation, to make it easy to use test_and_set_bit() in order to make sure only one task does this initial flush. Once we're into the transaction commit we only have one thread doing delayed ref running, it's just this initial pre-flush that is problematic. With this patch my stress test takes around 90 minutes to run, instead of 12 hours. The memory barrier is not necessary for the flushing bit as it's ordered, unlike plain int. The transaction state accessed in btrfs_should_end_transaction could be affected by that too as it's not always used under transaction lock. Upon Nikolay's analysis in [1] it's not necessary: In should_end_transaction it's read without holding any locks. (U) It's modified in btrfs_cleanup_transaction without holding the fs_info->trans_lock (U), but the STATE_ERROR flag is going to be set. set in cleanup_transaction under fs_info->trans_lock (L) set in btrfs_commit_trans to COMMIT_START under fs_info->trans_lock.(L) set in btrfs_commit_trans to COMMIT_DOING under fs_info->trans_lock.(L) set in btrfs_commit_trans to COMMIT_UNBLOCK under fs_info->trans_lock.(L) set in btrfs_commit_trans to COMMIT_COMPLETED without locks but at this point the transaction is finished and fs_info->running_trans is NULL (U but irrelevant). So by the looks of it we can have a concurrent READ race with a WRITE, due to reads not taking a lock. In this case what we want to ensure is we either see new or old state. I consulted with Will Deacon and he said that in such a case we'd want to annotate the accesses to ->state with (READ|WRITE)_ONCE so as to avoid a theoretical tear, in this case I don't think this could happen but I imagine at some point KCSAN would flag such an access as racy (which it is). [1] https://lore.kernel.org/linux-btrfs/e1fd5cc1-0f28-f670-69f4-e9958b4964e6@suse.comReviewed-by:
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Josef Bacik authored
While running some stress tests I started getting hung task messages. This is because the delete unused block groups code has to take the delete_unused_bgs_mutex to do it's work, which is taken by balance to make sure we don't delete block groups while we're balancing. The problem is that balance can take a while, and so we were getting hung task warnings. We don't need to block and run these things, and the cleaner is needed to do other work, so trylock on this mutex and just bail if we can't acquire it right away. Reviewed-by:
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Josef Bacik authored
While testing my error handling patches, I added a error injection site at btrfs_inc_extent_ref, to validate the error handling I added was doing the correct thing. However I hit a pretty ugly corruption while doing this check, with the following error injection stack trace: btrfs_inc_extent_ref btrfs_copy_root create_reloc_root btrfs_init_reloc_root btrfs_record_root_in_trans btrfs_start_transaction btrfs_update_inode btrfs_update_time touch_atime file_accessed btrfs_file_mmap This is because we do not catch the error from btrfs_inc_extent_ref, which in practice would be ENOMEM, which means we lose the extent references for a root that has already been allocated and inserted, which is the problem. Fix this by aborting the transaction if we fail to do the reference modification. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: -
Josef Bacik authored
A weird KASAN problem that Zygo reported could have been easily caught if we checked for basic things in our backref freeing code. We have two methods of freeing a backref node - btrfs_backref_free_node: this just is kfree() essentially. - btrfs_backref_drop_node: this actually unlinks the node and cleans up everything and then calls btrfs_backref_free_node(). We should mostly be using btrfs_backref_drop_node(), to make sure the node is properly unlinked from the backref cache, and only use btrfs_backref_free_node() when we know the node isn't actually linked to the backref cache. We made a mistake here and thus got the KASAN splat. Make this style of issue easier to find by adding some ASSERT()'s to btrfs_backref_free_node() and adjusting our deletion stuff to properly init the list so we can rely on list_empty() checks working properly. BUG: KASAN: use-after-free in btrfs_backref_cleanup_node+0x18a/0x420 Read of size 8 at addr ffff888112402950 by task btrfs/28836 CPU: 0 PID: 28836 Comm: btrfs Tainted: G W 5.10.0-e35f27394290-for-next+ #23 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack+0xbc/0xf9 ? btrfs_backref_cleanup_node+0x18a/0x420 print_address_description.constprop.8+0x21/0x210 ? record_print_text.cold.34+0x11/0x11 ? btrfs_backref_cleanup_node+0x18a/0x420 ? btrfs_backref_cleanup_node+0x18a/0x420 kasan_report.cold.10+0x20/0x37 ? btrfs_backref_cleanup_node+0x18a/0x420 __asan_load8+0x69/0x90 btrfs_backref_cleanup_node+0x18a/0x420 btrfs_backref_release_cache+0x83/0x1b0 relocate_block_group+0x394/0x780 ? merge_reloc_roots+0x4a0/0x4a0 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x1900 ? check_flags.part.50+0x6c/0x1e0 ? btrfs_relocate_chunk+0x120/0x120 ? kmem_cache_alloc_trace+0xa06/0xcb0 ? _copy_from_user+0x83/0xc0 btrfs_ioctl_balance+0x3a7/0x460 btrfs_ioctl+0x24c8/0x4360 ? __kasan_check_read+0x11/0x20 ? check_chain_key+0x1f4/0x2f0 ? __asan_loadN+0xf/0x20 ? btrfs_ioctl_get_supported_features+0x30/0x30 ? kvm_sched_clock_read+0x18/0x30 ? check_chain_key+0x1f4/0x2f0 ? lock_downgrade+0x3f0/0x3f0 ? handle_mm_fault+0xad6/0x2150 ? do_vfs_ioctl+0xfc/0x9d0 ? ioctl_file_clone+0xe0/0xe0 ? check_flags.part.50+0x6c/0x1e0 ? check_flags.part.50+0x6c/0x1e0 ? check_flags+0x26/0x30 ? lock_is_held_type+0xc3/0xf0 ? syscall_enter_from_user_mode+0x1b/0x60 ? do_syscall_64+0x13/0x80 ? rcu_read_lock_sched_held+0xa1/0xd0 ? __kasan_check_read+0x11/0x20 ? __fget_light+0xae/0x110 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4c4bdfe427 RSP: 002b:00007fff33ee6df8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fff33ee6e98 RCX: 00007f4c4bdfe427 RDX: 00007fff33ee6e98 RSI: 00000000c4009420 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078 R10: fffffffffffff59d R11: 0000000000000202 R12: 0000000000000001 R13: 0000000000000000 R14: 00007fff33ee8a34 R15: 0000000000000001 Allocated by task 28836: kasan_save_stack+0x21/0x50 __kasan_kmalloc.constprop.18+0xbe/0xd0 kasan_kmalloc+0x9/0x10 kmem_cache_alloc_trace+0x410/0xcb0 btrfs_backref_alloc_node+0x46/0xf0 btrfs_backref_add_tree_node+0x60d/0x11d0 build_backref_tree+0xc5/0x700 relocate_tree_blocks+0x2be/0xb90 relocate_block_group+0x2eb/0x780 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x1900 btrfs_ioctl_balance+0x3a7/0x460 btrfs_ioctl+0x24c8/0x4360 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 28836: kasan_save_stack+0x21/0x50 kasan_set_track+0x20/0x30 kasan_set_free_info+0x1f/0x30 __kasan_slab_free+0xf3/0x140 kasan_slab_free+0xe/0x10 kfree+0xde/0x200 btrfs_backref_error_cleanup+0x452/0x530 build_backref_tree+0x1a5/0x700 relocate_tree_blocks+0x2be/0xb90 relocate_block_group+0x2eb/0x780 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x1900 btrfs_ioctl_balance+0x3a7/0x460 btrfs_ioctl+0x24c8/0x4360 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888112402900 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 80 bytes inside of 128-byte region [ffff888112402900, ffff888112402980) The buggy address belongs to the page: page:0000000028b1cd08 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888131c810c0 pfn:0x112402 flags: 0x17ffe0000000200(slab) raw: 017ffe0000000200 ffffea000424f308 ffffea0007d572c8 ffff888100040440 raw: ffff888131c810c0 ffff888112402000 0000000100000009 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888112402800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888112402880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888112402900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888112402980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888112402a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Link: https://lore.kernel.org/linux-btrfs/20201208194607.GI31381@hungrycats.org/ CC: stable@vger.kernel.org # 5.10+ Signed-off-by: -
Josef Bacik authored
The backref code is looking for a reloc_root that corresponds to the given fs root. However any number of things could have gone wrong while initializing that reloc_root, like ENOMEM while trying to allocate the root itself, or EIO while trying to write the root item. This would result in no corresponding reloc_root being in the reloc root cache, and thus would return NULL when we do the find_reloc_root() call. Because of this we do not want to WARN_ON(). This presumably was meant to catch developer errors, cases where we messed up adding the reloc root. However we can easily hit this case with error injection, and thus should not do a WARN_ON(). CC: stable@vger.kernel.org # 5.10+ Reported-by:
Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Signed-off-by:
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Josef Bacik authored
While doing error injection testing with my relocation patches I hit the following assert: assertion failed: list_empty(&block_group->dirty_list), in fs/btrfs/block-group.c:3356 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.h:3357! invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 PID: 24351 Comm: umount Tainted: G W 5.10.0-rc3+ #193 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:assertfail.constprop.0+0x18/0x1a RSP: 0018:ffffa09b019c7e00 EFLAGS: 00010282 RAX: 0000000000000056 RBX: ffff8f6492c18000 RCX: 0000000000000000 RDX: ffff8f64fbc27c60 RSI: ffff8f64fbc19050 RDI: ffff8f64fbc19050 RBP: ffff8f6483bbdc00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffa09b019c7c38 R11: ffffffff85d70928 R12: ffff8f6492c18100 R13: ffff8f6492c18148 R14: ffff8f6483bbdd70 R15: dead000000000100 FS: 00007fbfda4cdc40(0000) GS:ffff8f64fbc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbfda666fd0 CR3: 000000013cf66002 CR4: 0000000000370ef0 Call Trace: btrfs_free_block_groups.cold+0x55/0x55 close_ctree+0x2c5/0x306 ? fsnotify_destroy_marks+0x14/0x100 generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 deactivate_locked_super+0x36/0xa0 cleanup_mnt+0x12d/0x190 task_work_run+0x5c/0xa0 exit_to_user_mode_prepare+0x1b1/0x1d0 syscall_exit_to_user_mode+0x54/0x280 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This happened because I injected an error in btrfs_cow_block() while running the dirty block groups. When we run the dirty block groups, we splice the list onto a local list to process. However if an error occurs, we only cleanup the transactions dirty block group list, not any pending block groups we have on our locally spliced list. In fact if we fail to allocate a path in this function we'll also fail to clean up the splice list. Fix this by splicing the list back onto the transaction dirty block group list so that the block groups are cleaned up. Then add a 'out' label and have the error conditions jump to out so that the errors are handled properly. This also has the side-effect of fixing a problem where we would clear 'ret' on error because we unconditionally ran btrfs_run_delayed_refs(). CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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Josef Bacik authored
When recovering a relocation, if we run into a reloc root that has 0 refs we simply add it to the reloc_control->reloc_roots list, and then clean it up later. The problem with this is __del_reloc_root() doesn't do anything if the root isn't in the radix tree, which in this case it won't be because we never call __add_reloc_root() on the reloc_root. This exit condition simply isn't correct really. During normal operation we can remove ourselves from the rb tree and then we're meant to clean up later at merge_reloc_roots() time, and this happens correctly. During recovery we're depending on free_reloc_roots() to drop our references, but we're short-circuiting. Fix this by continuing to check if we're on the list and dropping ourselves from the reloc_control root list and dropping our reference appropriately. Change the corresponding BUG_ON() to an ASSERT() that does the correct thing if we aren't in the rb tree. CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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Nigel Christian authored
Comment for processed extent end of range has an unnecessary "in", remove it. Signed-off-by:
Nigel Christian <nigel.l.christian@gmail.com> Reviewed-by:
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Josef Bacik authored
My recent patch set "A variety of lock contention fixes", found here https://lore.kernel.org/linux-btrfs/cover.1608319304.git.josef@toxicpanda.com/ (Tracked in https://github.com/btrfs/linux/issues/86) that reduce lock contention on the extent root by running delayed refs less often resulted in a regression in generic/371. This test fallocate()'s the fs until it's full, deletes all the files, and then tries to fallocate() until full again. Before these patches we would run all of the delayed refs during flushing, and then would commit the transaction because we had plenty of pinned space to recover in order to allocate. However my patches made it so we weren't running the delayed refs as aggressively, which meant that we appeared to have less pinned space when we were deciding to commit the transaction. We use the space_info->total_bytes_pinned to approximate how much space we have pinned. It's approximate because if we remove a reference to an extent we may free it, but there may be more references to it than we know of at that point, but we account it as pinned at the creation time, and then it's properly accounted when the delayed ref runs. The way we account for pinned space is if the delayed_ref_head->total_ref_mod is < 0, because that is clearly a freeing option. However there is another case, and that is where ->total_ref_mod == 0 && ->must_insert_reserved == 1. When we allocate a new extent, we have ->total_ref_mod == 1 and we have ->must_insert_reserved == 1. This is used to indicate that it is a brand new extent and will need to have its extent entry added before we modify any references on the delayed ref head. But if we subsequently remove that extent reference, our ->total_ref_mod will be 0, and that space will be pinned and freed. Accounting for this case properly allows for generic/371 to pass with my delayed refs patches applied. It's important to note that this problem exists without the referenced patches, it just was uncovered by them. CC: stable@vger.kernel.org # 5.10 Reviewed-by:
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Josef Bacik authored
Currently we pass things around to figure out if we maybe freeing data based on the state of the delayed refs head. This makes the accounting sort of confusing and hard to follow, as it's distinctly separate from the delayed ref heads stuff, but also depends on it entirely. Fix this by explicitly adjusting the space_info->total_bytes_pinned in the delayed refs code. We now have two places where we modify this counter, once where we create the delayed and destroy the delayed refs, and once when we pin and unpin the extents. This means there is a slight overlap between delayed refs and the pin/unpin mechanisms, but this is simply used by the ENOSPC infrastructure to determine if we need to commit the transaction, so there's no adverse affect from this, we might simply commit thinking it will give us enough space when it might not. CC: stable@vger.kernel.org # 5.10 Reviewed-by:
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Nikolay Borisov authored
Now that the btrfs' codebase is clean of almost all W=1 warnings let's enable those checks unconditionally for the entire fs/btrfs/ and its subdirectories to catch potential errors during development. Signed-off-by:
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Nikolay Borisov authored
These constants are really used internally by zstd and including linux/zstd.h into users results in the following warnings: In file included from fs/btrfs/zstd.c:19: ./include/linux/zstd.h:798:21: warning: ‘ZSTD_skippableHeaderSize’ defined but not used [-Wunused-const-variable=] 798 | static const size_t ZSTD_skippableHeaderSize = 8; | ^~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/zstd.h:796:21: warning: ‘ZSTD_frameHeaderSize_max’ defined but not used [-Wunused-const-variable=] 796 | static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX; | ^~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/zstd.h:795:21: warning: ‘ZSTD_frameHeaderSize_min’ defined but not used [-Wunused-const-variable=] 795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN; | ^~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/zstd.h:794:21: warning: ‘ZSTD_frameHeaderSize_prefix’ defined but not used [-Wunused-const-variable=] 794 | static const size_t ZSTD_frameHeaderSize_prefix = 5; So fix those warnings by turning the constants into defines. Reviewed-by:Nick Terrell <terrelln@fb.com> Signed-off-by:
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Nikolay Borisov authored
This fixes warning: fs/btrfs/zoned.c:491:6: warning: variable ‘zone_size’ set but not used [-Wunused-but-set-variable] 491 | u64 zone_size; which got introduced in 12659251 ("btrfs: implement log-structured superblock for ZONED mode"). We'll enable the warning by default and want clean build until the relevant zoned patches land. Signed-off-by:
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Nikolay Borisov authored
This makes the file W=1 clean and fixes the following warnings: fs/btrfs/extent_io.c:414: warning: Function parameter or member 'tree' not described in '__etree_search' fs/btrfs/extent_io.c:414: warning: Function parameter or member 'offset' not described in '__etree_search' fs/btrfs/extent_io.c:414: warning: Function parameter or member 'next_ret' not described in '__etree_search' fs/btrfs/extent_io.c:414: warning: Function parameter or member 'prev_ret' not described in '__etree_search' fs/btrfs/extent_io.c:414: warning: Function parameter or member 'p_ret' not described in '__etree_search' fs/btrfs/extent_io.c:414: warning: Function parameter or member 'parent_ret' not described in '__etree_search' fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'tree' not described in 'find_contiguous_extent_bit' fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'start' not described in 'find_contiguous_extent_bit' fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'start_ret' not described in 'find_contiguous_extent_bit' fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'end_ret' not described in 'find_contiguous_extent_bit' fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'bits' not described in 'find_contiguous_extent_bit' fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'tree' not described in 'find_first_clear_extent_bit' fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'start' not described in 'find_first_clear_extent_bit' fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'start_ret' not described in 'find_first_clear_extent_bit' fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'end_ret' not described in 'find_first_clear_extent_bit' fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'bits' not described in 'find_first_clear_extent_bit' fs/btrfs/extent_io.c:4187: warning: Function parameter or member 'epd' not described in 'extent_write_cache_pages' fs/btrfs/extent_io.c:4187: warning: Excess function parameter 'data' description in 'extent_write_cache_pages' Signed-off-by:
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Nikolay Borisov authored
With these fixes space-info.c is clear for W=1 warnings, namely the following ones are fixed: fs/btrfs/space-info.c:575: warning: Function parameter or member 'fs_info' not described in 'may_commit_transaction' fs/btrfs/space-info.c:575: warning: Function parameter or member 'space_info' not described in 'may_commit_transaction' fs/btrfs/space-info.c:1231: warning: Function parameter or member 'fs_info' not described in 'handle_reserve_ticket' fs/btrfs/space-info.c:1231: warning: Function parameter or member 'space_info' not described in 'handle_reserve_ticket' fs/btrfs/space-info.c:1231: warning: Function parameter or member 'ticket' not described in 'handle_reserve_ticket' fs/btrfs/space-info.c:1231: warning: Function parameter or member 'flush' not described in 'handle_reserve_ticket' fs/btrfs/space-info.c:1315: warning: Function parameter or member 'fs_info' not described in '__reserve_bytes' fs/btrfs/space-info.c:1315: warning: Function parameter or member 'space_info' not described in '__reserve_bytes' fs/btrfs/space-info.c:1315: warning: Function parameter or member 'orig_bytes' not described in '__reserve_bytes' fs/btrfs/space-info.c:1315: warning: Function parameter or member 'flush' not described in '__reserve_bytes' fs/btrfs/space-info.c:1427: warning: Function parameter or member 'root' not described in 'btrfs_reserve_metadata_bytes' fs/btrfs/space-info.c:1427: warning: Function parameter or member 'block_rsv' not described in 'btrfs_reserve_metadata_bytes' fs/btrfs/space-info.c:1427: warning: Function parameter or member 'orig_bytes' not described in 'btrfs_reserve_metadata_bytes' fs/btrfs/space-info.c:1427: warning: Function parameter or member 'flush' not described in 'btrfs_reserve_metadata_bytes' fs/btrfs/space-info.c:1462: warning: Function parameter or member 'fs_info' not described in 'btrfs_reserve_data_bytes' fs/btrfs/space-info.c:1462: warning: Function parameter or member 'bytes' not described in 'btrfs_reserve_data_bytes' fs/btrfs/space-info.c:1462: warning: Function parameter or member 'flush' not described in 'btrfs_reserve_data_bytes' Signed-off-by:
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Nikolay Borisov authored
Fixes following warnings: fs/btrfs/delalloc-space.c:205: warning: Function parameter or member 'inode' not described in 'btrfs_inode_rsv_release' fs/btrfs/delalloc-space.c:205: warning: Function parameter or member 'qgroup_free' not described in 'btrfs_inode_rsv_release' fs/btrfs/delalloc-space.c:472: warning: Function parameter or member 'reserved' not described in 'btrfs_delalloc_release_space' fs/btrfs/delalloc-space.c:472: warning: Function parameter or member 'qgroup_free' not described in 'btrfs_delalloc_release_space' fs/btrfs/delalloc-space.c:472: warning: Excess function parameter 'release_bytes' description in 'btrfs_delalloc_release_space' Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
Fixes fs/btrfs/inode.c:3101: warning: Function parameter or member 'fs_info' not described in 'btrfs_wait_on_delayed_iputs' Signed-off-by:
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Nikolay Borisov authored
Fixes fs/btrfs/block-group.c:1570: warning: Function parameter or member 'fs_info' not described in 'btrfs_rmap_block' Signed-off-by:
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Nikolay Borisov authored
Fixes fs/btrfs/discard.c:203: warning: Function parameter or member 'now' not described in 'peek_discard_list' Signed-off-by:
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Nikolay Borisov authored
Fixes following W=1 warnings: fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'root' not described in '__btrfs_write_out_cache' fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'inode' not described in '__btrfs_write_out_cache' fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'ctl' not described in '__btrfs_write_out_cache' fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'block_group' not described in '__btrfs_write_out_cache' fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'io_ctl' not described in '__btrfs_write_out_cache' fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'trans' not described in '__btrfs_write_out_cache' Signed-off-by:
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Nikolay Borisov authored
This fixes the following warnings: fs/btrfs/delayed-ref.c:80: warning: Function parameter or member 'fs_info' not described in 'btrfs_delayed_refs_rsv_release' fs/btrfs/delayed-ref.c:80: warning: Function parameter or member 'nr' not described in 'btrfs_delayed_refs_rsv_release' fs/btrfs/delayed-ref.c:128: warning: Function parameter or member 'fs_info' not described in 'btrfs_migrate_to_delayed_refs_rsv' fs/btrfs/delayed-ref.c:128: warning: Function parameter or member 'src' not described in 'btrfs_migrate_to_delayed_refs_rsv' fs/btrfs/delayed-ref.c:128: warning: Function parameter or member 'num_bytes' not described in 'btrfs_migrate_to_delayed_refs_rsv' fs/btrfs/delayed-ref.c:174: warning: Function parameter or member 'fs_info' not described in 'btrfs_delayed_refs_rsv_refill' fs/btrfs/delayed-ref.c:174: warning: Function parameter or member 'flush' not described in 'btrfs_delayed_refs_rsv_refill' Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
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Nikolay Borisov authored
This fixes following W=1 warnings: fs/btrfs/file-item.c:27: warning: Cannot understand * @inode: the inode we want to update the disk_i_size for on line 27 - I thought it was a doc line fs/btrfs/file-item.c:65: warning: Cannot understand * @inode - the inode we're modifying on line 65 - I thought it was a doc line fs/btrfs/file-item.c:91: warning: Cannot understand * @inode - the inode we're modifying on line 91 - I thought it was a doc line Signed-off-by:
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Nikolay Borisov authored
This fixes the following compiler warnings: fs/btrfs/extent_map.c:601: warning: Function parameter or member 'fs_info' not described in 'btrfs_add_extent_mapping' fs/btrfs/extent_map.c:601: warning: Function parameter or member 'em_tree' not described in 'btrfs_add_extent_mapping' fs/btrfs/extent_map.c:601: warning: Function parameter or member 'em_in' not described in 'btrfs_add_extent_mapping' fs/btrfs/extent_map.c:601: warning: Function parameter or member 'start' not described in 'btrfs_add_extent_mapping' fs/btrfs/extent_map.c:601: warning: Function parameter or member 'len' not described in 'btrfs_add_extent_mapping' Reviewed-by:
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Nikolay Borisov authored
Fixes fs/btrfs/extent_map.c:399: warning: Function parameter or member 'modified' not described in 'add_extent_mapping' Reviewed-by:
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Qu Wenruo authored
[BUG] There is a long existing bug in the last parameter of btrfs_add_ordered_extent(), in commit 771ed689 ("Btrfs: Optimize compressed writeback and reads") back to 2008. In that ancient commit btrfs_add_ordered_extent() expects the @type parameter to be one of the following: - BTRFS_ORDERED_REGULAR - BTRFS_ORDERED_NOCOW - BTRFS_ORDERED_PREALLOC - BTRFS_ORDERED_COMPRESSED But we pass 0 in cow_file_range(), which means BTRFS_ORDERED_IO_DONE. Ironically extra check in __btrfs_add_ordered_extent() won't set the bit if we see (type == IO_DONE || type == IO_COMPLETE), and avoid any obvious bug. But this still leads to regular COW ordered extent having no bit to indicate its type in various trace events, rendering REGULAR bit useless. [FIX] Change the following aspects to avoid such problem: - Reorder btrfs_ordered_extent::flags Now the type bits go first (REGULAR/NOCOW/PREALLCO/COMPRESSED), then DIRECT bit, finally extra status bits like IO_DONE/COMPLETE/IOERR. - Add extra ASSERT() for btrfs_add_ordered_extent_*() - Remove @type parameter for btrfs_add_ordered_extent_compress() As the only valid @type here is BTRFS_ORDERED_COMPRESSED. - Remove the unnecessary special check for IO_DONE/COMPLETE in __btrfs_add_ordered_extent() This is just to make the code work, with extra ASSERT(), there are limited values can be passed in. Reviewed-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
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Yang Li authored
Fix below warnings reported by coccicheck: ./fs/btrfs/raid56.c:237:2-8: WARNING: NULL check before some freeing functions is not needed. Reported-by:
Abaci Robot <abaci@linux.alibaba.com> Reviewed-by:
Anand Jain <anand.jain@oracle.com> Signed-off-by:
Yang Li <abaci-bugfix@linux.alibaba.com> Reviewed-by:
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Josef Bacik authored
Zygo reported the following panic when testing my error handling patches for relocation: kernel BUG at fs/btrfs/backref.c:2545! invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 3 PID: 8472 Comm: btrfs Tainted: G W 14 Hardware name: QEMU Standard PC (i440FX + PIIX, Call Trace: btrfs_backref_error_cleanup+0x4df/0x530 build_backref_tree+0x1a5/0x700 ? _raw_spin_unlock+0x22/0x30 ? release_extent_buffer+0x225/0x280 ? free_extent_buffer.part.52+0xd7/0x140 relocate_tree_blocks+0x2a6/0xb60 ? kasan_unpoison_shadow+0x35/0x50 ? do_relocation+0xc10/0xc10 ? kasan_kmalloc+0x9/0x10 ? kmem_cache_alloc_trace+0x6a3/0xcb0 ? free_extent_buffer.part.52+0xd7/0x140 ? rb_insert_color+0x342/0x360 ? add_tree_block.isra.36+0x236/0x2b0 relocate_block_group+0x2eb/0x780 ? merge_reloc_roots+0x470/0x470 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x18f0 ? pvclock_clocksource_read+0xeb/0x190 ? btrfs_relocate_chunk+0x120/0x120 ? lock_contended+0x620/0x6e0 ? do_raw_spin_lock+0x1e0/0x1e0 ? do_raw_spin_unlock+0xa8/0x140 btrfs_ioctl_balance+0x1f9/0x460 btrfs_ioctl+0x24c8/0x4380 ? __kasan_check_read+0x11/0x20 ? check_chain_key+0x1f4/0x2f0 ? __asan_loadN+0xf/0x20 ? btrfs_ioctl_get_supported_features+0x30/0x30 ? kvm_sched_clock_read+0x18/0x30 ? check_chain_key+0x1f4/0x2f0 ? lock_downgrade+0x3f0/0x3f0 ? handle_mm_fault+0xad6/0x2150 ? do_vfs_ioctl+0xfc/0x9d0 ? ioctl_file_clone+0xe0/0xe0 ? check_flags.part.50+0x6c/0x1e0 ? check_flags.part.50+0x6c/0x1e0 ? check_flags+0x26/0x30 ? lock_is_held_type+0xc3/0xf0 ? syscall_enter_from_user_mode+0x1b/0x60 ? do_syscall_64+0x13/0x80 ? rcu_read_lock_sched_held+0xa1/0xd0 ? __kasan_check_read+0x11/0x20 ? __fget_light+0xae/0x110 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This occurs because of this check if (RB_EMPTY_NODE(&upper->rb_node)) BUG_ON(!list_empty(&node->upper)); As we are dropping the backref node, if we discover that our upper node in the edge we just cleaned up isn't linked into the cache that we are now done with this node, thus the BUG_ON(). However this is an erroneous assumption, as we will look up all the references for a node first, and then process the pending edges. All of the 'upper' nodes in our pending edges won't be in the cache's rb_tree yet, because they haven't been processed. We could very well have many edges still left to cleanup on this node. The fact is we simply do not need this check, we can just process all of the edges only for this node, because below this check we do the following if (list_empty(&upper->lower)) { list_add_tail(&upper->lower, &cache->leaves); upper->lowest = 1; } If the upper node truly isn't used yet, then we add it to the cache->leaves list to be cleaned up later. If it is still used then the last child node that has it linked into its node will add it to the leaves list and then it will be cleaned up. Fix this problem by dropping this logic altogether. With this fix I no longer see the panic when testing with error injection in the backref code. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: -
Josef Bacik authored
While testing the error paths in relocation, I hit the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.10.0-rc3+ #206 Not tainted ------------------------------------------------------ btrfs-balance/1571 is trying to acquire lock: ffff8cdbcc8f77d0 (&head_ref->mutex){+.+.}-{3:3}, at: btrfs_lookup_extent_info+0x156/0x3b0 but task is already holding lock: ffff8cdbc54adbf8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x100 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (btrfs-tree-00){++++}-{3:3}: down_write_nested+0x43/0x80 __btrfs_tree_lock+0x27/0x100 btrfs_search_slot+0x248/0x890 relocate_tree_blocks+0x490/0x650 relocate_block_group+0x1ba/0x5d0 kretprobe_trampoline+0x0/0x50 -> #1 (btrfs-csum-01){++++}-{3:3}: down_read_nested+0x43/0x130 __btrfs_tree_read_lock+0x27/0x100 btrfs_read_lock_root_node+0x31/0x40 btrfs_search_slot+0x5ab/0x890 btrfs_del_csums+0x10b/0x3c0 __btrfs_free_extent+0x49d/0x8e0 __btrfs_run_delayed_refs+0x283/0x11f0 btrfs_run_delayed_refs+0x86/0x220 btrfs_start_dirty_block_groups+0x2ba/0x520 kretprobe_trampoline+0x0/0x50 -> #0 (&head_ref->mutex){+.+.}-{3:3}: __lock_acquire+0x1167/0x2150 lock_acquire+0x116/0x3e0 __mutex_lock+0x7e/0x7b0 btrfs_lookup_extent_info+0x156/0x3b0 walk_down_proc+0x1c3/0x280 walk_down_tree+0x64/0xe0 btrfs_drop_subtree+0x182/0x260 do_relocation+0x52e/0x660 relocate_tree_blocks+0x2ae/0x650 relocate_block_group+0x1ba/0x5d0 kretprobe_trampoline+0x0/0x50 other info that might help us debug this: Chain exists of: &head_ref->mutex --> btrfs-csum-01 --> btrfs-tree-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-tree-00); lock(btrfs-csum-01); lock(btrfs-tree-00); lock(&head_ref->mutex); *** DEADLOCK *** 5 locks held by btrfs-balance/1571: #0: ffff8cdb89749ff8 (&fs_info->delete_unused_bgs_mutex){+.+.}-{3:3}, at: btrfs_balance+0x563/0xf40 #1: ffff8cdb89748838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x156/0x300 #2: ffff8cdbc2c16650 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x413/0x5c0 #3: ffff8cdbc135f538 (btrfs-treloc-01){+.+.}-{3:3}, at: __btrfs_tree_lock+0x27/0x100 #4: ffff8cdbc54adbf8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x100 stack backtrace: CPU: 1 PID: 1571 Comm: btrfs-balance Not tainted 5.10.0-rc3+ #206 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x8b/0xb0 check_noncircular+0xcf/0xf0 ? trace_call_bpf+0x139/0x260 __lock_acquire+0x1167/0x2150 lock_acquire+0x116/0x3e0 ? btrfs_lookup_extent_info+0x156/0x3b0 __mutex_lock+0x7e/0x7b0 ? btrfs_lookup_extent_info+0x156/0x3b0 ? btrfs_lookup_extent_info+0x156/0x3b0 ? release_extent_buffer+0x124/0x170 ? _raw_spin_unlock+0x1f/0x30 ? release_extent_buffer+0x124/0x170 btrfs_lookup_extent_info+0x156/0x3b0 walk_down_proc+0x1c3/0x280 walk_down_tree+0x64/0xe0 btrfs_drop_subtree+0x182/0x260 do_relocation+0x52e/0x660 relocate_tree_blocks+0x2ae/0x650 ? add_tree_block+0x149/0x1b0 relocate_block_group+0x1ba/0x5d0 elfcorehdr_read+0x40/0x40 ? elfcorehdr_read+0x40/0x40 ? btrfs_balance+0x796/0xf40 ? __kthread_parkme+0x66/0x90 ? btrfs_balance+0xf40/0xf40 ? balance_kthread+0x37/0x50 ? kthread+0x137/0x150 ? __kthread_bind_mask+0x60/0x60 ? ret_from_fork+0x1f/0x30 As you can see this is bogus, we never take another tree's lock under the csum lock. This happens because sometimes we have to read tree blocks from disk without knowing which root they belong to during relocation. We defaulted to an owner of 0, which translates to an fs tree. This is fine as all fs trees have the same class, but obviously isn't fine if the block belongs to a COW only tree. Thankfully COW only trees only have their owners root as a reference to them, and since we already look up the extent information during relocation, go ahead and check and see if this block might belong to a COW only tree, and if so save the owner in the tree_block struct. This allows us to read_tree_block with the proper owner, which gets rid of this lockdep splat. Signed-off-by: -
Qu Wenruo authored
This patch will extract the code to grab an extent buffer from a page into a helper, grab_extent_buffer_from_page(). This reduces one indent level, and provides the work place for later expansion for subapge support. Reviewed-by:
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Qu Wenruo authored
The original comment is from the initial merge, which has several problems: - No holes check any more - No inline decision is made Update the out-of-date comment with more correct one. Signed-off-by:
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Qu Wenruo authored
The refactoring involves the following modifications: - iosize alignment In fact we don't really need to manually do alignment at all. All extent maps should already be aligned, thus basic ASSERT() check would be enough. - redundant variables We have extra variable like blocksize/pg_offset/end. They are all unnecessary. @blocksize can be replaced by sectorsize size directly, and it's only used to verify the em start/size is aligned. @pg_offset can be easily calculated using @cur and page_offset(page). @end is just assigned from @page_end and never modified, use "start + PAGE_SIZE - 1" directly and remove @page_end. - remove some BUG_ON()s The BUG_ON()s are for extent map, which we have tree-checker to check on-disk extent data item and runtime check. ASSERT() should be enough. Reviewed-by:
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Qu Wenruo authored
The parameter offset is confusing, it's supposed to be the disk bytenr of metadata/data. Rename it to disk_bytenr and update the comment. Also rename each offset passed to submit_extent_page() as @disk_bytenr so they're consistent. Reviewed-by:
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Qu Wenruo authored
The refactoring involves the following modifications: - Return bool instead of int - Parameter update for @cached of btrfs_dec_test_first_ordered_pending() For btrfs_dec_test_first_ordered_pending(), @cached is only used to return the finished ordered extent. Rename it to @finished_ret. - Comment updates * Change one stale comment Which still refers to btrfs_dec_test_ordered_pending(), but the context is calling btrfs_dec_test_first_ordered_pending(). * Follow the common comment style for both functions Add more detailed descriptions for parameters and the return value * Move the reason why test_and_set_bit() is used into the call sites - Change how the return value is calculated The most anti-human part of the return value is: if (...) ret = 1; ... return ret == 0; This means, when we set ret to 1, the function returns 0. Change the local variable name to @finished, and directly return the value of it. Signed-off-by: -
Qu Wenruo authored
btrfs_dio_private::bytes is only assigned from bio::bi_iter::bi_size, which is never larger than U32. Signed-off-by:
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Nikolay Borisov authored
Following the rework in e076ab2a ("btrfs: shrink delalloc pages instead of full inodes") the nr variable is no longer passed by reference to start_delalloc_inodes hence it cannot change. Additionally we are always guaranteed for it to be positive number hence it's redundant to have it as a condition in the loop. Simply remove that usage. Reviewed-by:
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