- 15 Oct, 2018 40 commits
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Qu Wenruo authored
Number of qgroup dirty extents is directly linked to the performance overhead, so add a new trace event, trace_qgroup_num_dirty_extents(), to record how many dirty extents is processed in btrfs_qgroup_account_extents(). This will be pretty handy to analyze later balance performance improvement. Signed-off-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Qu Wenruo authored
fs/btrfs/relocation.c:build_backref_tree() is some code from 2009 era, although it works pretty fine, it's not that easy to understand. Especially combined with the complex btrfs backref format. This patch adds some basic comment for the backref build part of the code, making it less hard to read, at least for backref searching part. Signed-off-by:
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Omar Sandoval authored
The only aops we define for symlinks are identical to the aops for regular files. This has been the case since symlink support was added in commit 2b8d99a7 ("Btrfs: symlinks and hard links"). As far as I can tell, there wasn't a good reason to have separate aops then, and there isn't now, so let's just do what most other filesystems do and reuse the same structure. Signed-off-by:
Omar Sandoval <osandov@fb.com> Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
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Chris Mason authored
During buffered writes, we follow this basic series of steps: again: lock all the pages wait for writeback on all the pages Take the extent range lock wait for ordered extents on the whole range clean all the pages if (copy_from_user_in_atomic() hits a fault) { drop our locks goto again; } dirty all the pages release all the locks The extra waiting, cleaning and locking are there to make sure we don't modify pages in flight to the drive, after they've been crc'd. If some of the pages in the range were already dirty when the write began, and we need to goto again, we create a window where a dirty page has been cleaned and unlocked. It may be reclaimed before we're able to lock it again, which means we'll read the old contents off the drive and lose any modifications that had been pending writeback. We don't actually need to clean the pages. All of the other locking in place makes sure we don't start IO on the pages, so we can just leave them dirty for the duration of the write. Fixes: 73d59314 (the original btrfs merge) CC: stable@vger.kernel.org # v4.4+ Signed-off-by:Chris Mason <clm@fb.com> Reviewed-by:
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David Sterba authored
The helper does the same math and we take care about the special case when flags is 0 too. Reviewed-by:
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Nikolay Borisov authored
Refactor the delayed refs loop by using the newly introduced btrfs_run_delayed_refs_for_head function. This greatly simplifies __btrfs_run_delayed_refs and makes it more obvious what is happening. We now have 1 loop which iterates the existing delayed_heads and then each selected ref head is processed by the new helper. All existing semantics of the code are preserved so no functional changes. Signed-off-by:
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Nikolay Borisov authored
This patch introduces a new helper encompassing the implicit inner loop in __btrfs_run_delayed_refs which processes all the refs for a given head. The code is mostly copy/paste, the only difference is that if we detect a newer reference then -EAGAIN is returned so that callers can react correctly. Also, at the end of the loop the head is relocked and btrfs_merge_delayed_refs is run again to retain the pre-refactoring semantics. Signed-off-by:
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Nikolay Borisov authored
This is in preparation to refactor the giant loop in __btrfs_run_delayed_refs. As a first step define a new function which implements acquiring a reference to a btrfs_delayed_refs_head and use it. No functional changes. Signed-off-by:
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David Sterba authored
Avoid the inline ifdefs and use two sections for self-tests enabled and disabled. Though there could be no ifdef and unconditional test_bit of BTRFS_FS_STATE_DUMMY_FS_INFO, the static inline can help to optimize out any code that would depend on conditions using btrfs_is_testing. As this is only for the testing code, drop unlikely(). Reviewed-by:
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David Sterba authored
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David Sterba authored
The data used only for tests are better placed at the end of the structure so that they don't change the structure layout. All new members of btrfs_root should be placed before. Reviewed-by:
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David Sterba authored
The helper find_lock_delalloc_range is now conditionally built static, dpending on whether the self-tests are enabled or not. There's a macro that is supposed to hide the export, used only once. To discourage further use, drop it an add a public wrapper for the helper needed by tests. Reviewed-by:
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Liu Bo authored
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). While resolving indirect refs and missing refs, it always looks for the first rb entry in a while loop, it's helpful to use rb_first_cached instead. For more details about the optimization see patch "Btrfs: delayed-refs: use rb_first_cached for href_root". Tested-by:
Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by:
Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by:
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Liu Bo authored
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). As evict_inode_truncate_pages() removes all extent mapping by always looking for the first rb entry, it's helpful to use rb_first_cached instead. For more details about the optimization see patch "Btrfs: delayed-refs: use rb_first_cached for href_root". Tested-by:
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Liu Bo authored
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). Functions manipulating delayed_item need to get the first entry, this converts it to use rb_first_cached(). For more details about the optimization see patch "Btrfs: delayed-refs: use rb_first_cached for href_root". Tested-by:
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Liu Bo authored
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). Functions manipulating href->ref_tree need to get the first entry, this converts href->ref_tree to use rb_first_cached(). For more details about the optimization see patch "Btrfs: delayed-refs: use rb_first_cached for href_root". Tested-by:
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Liu Bo authored
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). Functions manipulating href_root need to get the first entry, this converts href_root to use rb_first_cached(). This patch is first in the sequenct of similar updates to other rbtrees and this is analysis of the expected behaviour and improvements. There's a common pattern: while (node = rb_first) { entry = rb_entry(node) next = rb_next(node) rb_erase(node) cleanup(entry) } rb_first needs to traverse the tree up to logN depth, rb_erase can completely reshuffle the tree. With the caching we'll skip the traversal in rb_first. That's a cached memory access vs looped pointer dereference trade-off that IMHO has a clear winner. Measurements show there's not much difference in a sample tree with 10000 nodes: 4.5s / rb_first and 4.8s / rb_first_cached. Real effects of caching and pointer chasing are unpredictable though. Further optimzations can be done to avoid the expensive rb_erase step. In some cases it's ok to process the nodes in any order, so the tree can be traversed in post-order, not rebalancing the children nodes and just calling free. Care must be taken regarding the next node. Tested-by: -
Josef Bacik authored
While testing my backport I noticed there was a panic if I ran generic/416 generic/417 generic/418 all in a row. This just happened to uncover a race where we had outstanding IO after we destroy all of our workqueues, and then we'd go to queue the endio work on those free'd workqueues. This is because we aren't waiting for the caching threads to be done before freeing everything up, so to fix this make sure we wait on any outstanding caching that's being done before we free up the block group, so we're sure to be done with all IO by the time we get to btrfs_stop_all_workers(). This fixes the panic I was seeing consistently in testing. ------------[ cut here ]------------ kernel BUG at fs/btrfs/volumes.c:6112! SMP PTI Modules linked in: CPU: 1 PID: 27165 Comm: kworker/u4:7 Not tainted 4.16.0-02155-g3553e54a578d-dirty #875 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Workqueue: btrfs-cache btrfs_cache_helper RIP: 0010:btrfs_map_bio+0x346/0x370 RSP: 0000:ffffc900061e79d0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff880071542e00 RCX: 0000000000533000 RDX: ffff88006bb74380 RSI: 0000000000000008 RDI: ffff880078160000 RBP: 0000000000000001 R08: ffff8800781cd200 R09: 0000000000503000 R10: ffff88006cd21200 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8800781cd200 R15: ffff880071542e00 FS: 0000000000000000(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000817ffc4 CR3: 0000000078314000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btree_submit_bio_hook+0x8a/0xd0 submit_one_bio+0x5d/0x80 read_extent_buffer_pages+0x18a/0x320 btree_read_extent_buffer_pages+0xbc/0x200 ? alloc_extent_buffer+0x359/0x3e0 read_tree_block+0x3d/0x60 read_block_for_search.isra.30+0x1a5/0x360 btrfs_search_slot+0x41b/0xa10 btrfs_next_old_leaf+0x212/0x470 caching_thread+0x323/0x490 normal_work_helper+0xc5/0x310 process_one_work+0x141/0x340 worker_thread+0x44/0x3c0 kthread+0xf8/0x130 ? process_one_work+0x340/0x340 ? kthread_bind+0x10/0x10 ret_from_fork+0x35/0x40 RIP: btrfs_map_bio+0x346/0x370 RSP: ffffc900061e79d0 ---[ end trace 827eb13e50846033 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
Josef Bacik <josef@toxicpanda.com> Reviewed-by:
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Jeff Mahoney authored
Commit 499f377f (btrfs: iterate over unused chunk space in FITRIM) fixed free space trimming, but introduced latency when it was running. This is due to it pinning the transaction using both a incremented refcount and holding the commit root sem for the duration of a single trim operation. This was to ensure safety but it's unnecessary. We already hold the the chunk mutex so we know that the chunk we're using can't be allocated while we're trimming it. In order to check against chunks allocated already in this transaction, we need to check the pending chunks list. To to that safely without joining the transaction (or attaching than then having to commit it) we need to ensure that the dev root's commit root doesn't change underneath us and the pending chunk lists stays around until we're done with it. We can ensure the former by holding the commit root sem and the latter by pinning the transaction. We do this now, but the critical section covers the trim operation itself and we don't need to do that. This patch moves the pinning and unpinning logic into helpers and unpins the transaction after performing the search and check for pending chunks. Limiting the critical section of the transaction pinning improves the latency substantially on slower storage (e.g. image files over NFS). Fixes: 499f377f ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
Jeff Mahoney <jeffm@suse.com> Reviewed-by:
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Jeff Mahoney authored
We check whether any device the file system is using supports discard in the ioctl call, but then we attempt to trim free extents on every device regardless of whether discard is supported. Due to the way we mask off EOPNOTSUPP, we can end up issuing the trim operations on each free range on devices that don't support it, just wasting time. Fixes: 499f377f ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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Jeff Mahoney authored
btrfs_trim_fs iterates over the fs_devices->alloc_list while holding the device_list_mutex. The problem is that ->alloc_list is protected by the chunk mutex. We don't want to hold the chunk mutex over the trim of the entire file system. Fortunately, the ->dev_list list is protected by the dev_list mutex and while it will give us all devices, including read-only devices, we already just skip the read-only devices. Then we can continue to take and release the chunk mutex while scanning each device. Fixes: 499f377f ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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Qu Wenruo authored
[BUG] fstrim on some btrfs only trims the unallocated space, not trimming any space in existing block groups. [CAUSE] Before fstrim_range passed to btrfs_trim_fs(), it gets truncated to range [0, super->total_bytes). So later btrfs_trim_fs() will only be able to trim block groups in range [0, super->total_bytes). While for btrfs, any bytenr aligned to sectorsize is valid, since btrfs uses its logical address space, there is nothing limiting the location where we put block groups. For filesystem with frequent balance, it's quite easy to relocate all block groups and bytenr of block groups will start beyond super->total_bytes. In that case, btrfs will not trim existing block groups. [FIX] Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs() can get the unmodified range, which is normally set to [0, U64_MAX]. Reported-by:
Chris Murphy <lists@colorremedies.com> Fixes: f4c697e6 ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl") CC: <stable@vger.kernel.org> # v4.4+ Signed-off-by:
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Qu Wenruo authored
Function btrfs_trim_fs() doesn't handle errors in a consistent way. If error happens when trimming existing block groups, it will skip the remaining blocks and continue to trim unallocated space for each device. The return value will only reflect the final error from device trimming. This patch will fix such behavior by: 1) Recording the last error from block group or device trimming The return value will also reflect the last error during trimming. Make developer more aware of the problem. 2) Continuing trimming if possible If we failed to trim one block group or device, we could still try the next block group or device. 3) Report number of failures during block group and device trimming It would be less noisy, but still gives user a brief summary of what's going wrong. Such behavior can avoid confusion for cases like failure to trim the first block group and then only unallocated space is trimmed. Reported-by:
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Jeff Mahoney authored
When we fail to start a transaction in btrfs_dev_replace_start, we leave dev_replace->replace_start set to STARTED but clear ->srcdev and ->tgtdev. Later, that can result in an Oops in btrfs_dev_replace_progress when having state set to STARTED or SUSPENDED implies that ->srcdev is valid. Also fix error handling when the state is already STARTED or SUSPENDED while starting. That, too, will clear ->srcdev and ->tgtdev even though it doesn't own them. This should be an impossible case to hit since we should be protected by the BTRFS_FS_EXCL_OP bit being set. Let's add an ASSERT there while we're at it. Fixes: e93c89c1 (Btrfs: add new sources for device replace code) CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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zhong jiang authored
remove_extent_mapping uses the variable "ret" for return value, but it is not modified after initialzation. Further, I find that any of the callers do not handle the return value and the callees are only simple functions so the return values does not need to be passed. Signed-off-by:
zhong jiang <zhongjiang@huawei.com> Reviewed-by:
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Nikolay Borisov authored
In btrfs_search_old_slot get_old_root is always used with the assumption it cannot fail. However, this is not true in rare circumstance it can fail and return null. This will lead to null point dereference when the header is read. Fix this by checking the return value and properly handling NULL by setting ret to -EIO and returning gracefully. Coverity-id: 1087503 Signed-off-by:
Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by:
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Nikolay Borisov authored
In btrfs_orphan_cleanup the final 'if (ret) goto out' cannot ever be executed. This is due to the last assignment to 'ret' depending on the return value of btrfs_iget. If an error other than -ENOENT is returned then the loop is prematurely terminated by 'goto out'. On the other hand, if the error value is ENOENT then a subsequent if branch is executed that always re-assigns 'ret' and in case it's an error just terminates the loop. No functional changes. Coverity-id: 1437392 Signed-off-by:
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Liu Bo authored
When we delete an inode, btrfs_evict_inode() { truncate_inode_pages_final() truncate_inode_pages_range() lock_page() truncate_cleanup_page() btrfs_invalidatepage() wait_on_page_writeback btrfs_lookup_ordered_range() cancel_dirty_page() unlock_page() ... btrfs_wait_ordered_range() ... As VFS has called ->invalidatepage() to get all ordered extents done (if there are any) and truncated all page cache pages (no dirty pages to writeback after this step), wait_ordered_range() is just a noop. Signed-off-by: -
Liu Bo authored
As long as @eb is marked with EXTENT_BUFFER_DIRTY, all of its pages are dirty, so no need to set pages dirty again. Ftrace showed that the loop took 10us on my dev box, so removing this can save us at least 10us if eb is already dirty and otherwise avoid a potentially expensive calls to set_page_dirty. Signed-off-by:
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Liu Bo authored
Just in case that someone breaks the rule that pages are dirty as long as eb is dirty. The next patch will dirty the pages conditionally. Signed-off-by:
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Liu Bo authored
In the callchain: btrfs_search_slot() if (level != 0) setup_nodes_for_search() balance_level() It is just impossible to have level=0 in balance_level, we can drop the check. Signed-off-by: -
Liu Bo authored
Unify the error handling of directory item lookups using IS_ERR_OR_NULL. No functional changes. Signed-off-by:
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Liu Bo authored
kcalloc is defined as: kcalloc(size_t n, size_t size, gfp_t flags) Although this won't cause problems in practice, btrfsic_read_block() uses kcalloc with n and size in the opposite order. Reviewed-by:
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Nikolay Borisov authored
Instead of returning an error value and using one of the parameters for returning the actual object we are interested in just refactor the function to directly return btrfs_device *. Also bubble up the error handling for the special BTRFS_ERROR_DEV_MISSING_NOT_FOUND value into btrfs_rm_device. No functional changes. Signed-off-by:
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Nikolay Borisov authored
This function returns a numeric error value and additionally the device found in one of its input parameters. Simplify this by making the function directly return a pointer to btrfs_device. Additionally adjust the caller to handle the case when we want to remove the 'missing' device and ENOENT is returned to return the expected positive error value, parsed by progs. Finally, unexport the function since it's not called outside of volume.c. No functional changes. Signed-off-by:
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Nikolay Borisov authored
Currently this function returns an error code as well as uses one of its arguments as a return value for struct btrfs_device. Change the function so that it returns btrfs_device directly and use the usual "encode error in pointer" mechanics if something goes wrong. No functional changes. Signed-off-by:
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Jeff Mahoney authored
When we hit an I/O error in free_log_tree->walk_log_tree during file system shutdown we can crash due to there not being a valid transaction handle. Use btrfs_handle_fs_error when there's no transaction handle to use. BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 IP: free_log_tree+0xd2/0x140 [btrfs] PGD 0 P4D 0 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI Modules linked in: <modules> CPU: 2 PID: 23544 Comm: umount Tainted: G W 4.12.14-kvmsmall #9 SLE15 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 task: ffff96bfd3478880 task.stack: ffffa7cf40d78000 RIP: 0010:free_log_tree+0xd2/0x140 [btrfs] RSP: 0018:ffffa7cf40d7bd10 EFLAGS: 00010282 RAX: 00000000fffffffb RBX: 00000000fffffffb RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff96c02f07d4c8 RDI: 0000000000000282 RBP: ffff96c013cf1000 R08: ffff96c02f07d4c8 R09: ffff96c02f07d4d0 R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 R13: ffff96c005e800c0 R14: ffffa7cf40d7bdb8 R15: 0000000000000000 FS: 00007f17856bcfc0(0000) GS:ffff96c03f600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000060 CR3: 0000000045ed6002 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? wait_for_writer+0xb0/0xb0 [btrfs] btrfs_free_log+0x17/0x30 [btrfs] btrfs_drop_and_free_fs_root+0x9a/0xe0 [btrfs] btrfs_free_fs_roots+0xc0/0x130 [btrfs] ? wait_for_completion+0xf2/0x100 close_ctree+0xea/0x2e0 [btrfs] ? kthread_stop+0x161/0x260 generic_shutdown_super+0x6c/0x120 kill_anon_super+0xe/0x20 btrfs_kill_super+0x13/0x100 [btrfs] deactivate_locked_super+0x3f/0x70 cleanup_mnt+0x3b/0x70 task_work_run+0x78/0x90 exit_to_usermode_loop+0x77/0xa6 do_syscall_64+0x1c5/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f1784f90827 RSP: 002b:00007ffdeeb03118 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000556a60c62970 RCX: 00007f1784f90827 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556a60c62b50 RBP: 0000000000000000 R08: 0000000000000005 R09: 00000000ffffffff R10: 0000556a60c63900 R11: 0000000000000246 R12: 0000556a60c62b50 R13: 00007f17854a81c4 R14: 0000000000000000 R15: 0000000000000000 RIP: free_log_tree+0xd2/0x140 [btrfs] RSP: ffffa7cf40d7bd10 CR2: 0000000000000060 Fixes: 681ae509 ("Btrfs: cleanup reserved space when freeing tree log on error") CC: <stable@vger.kernel.org> # v3.13 Signed-off-by:
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Misono Tomohiro authored
Since commit d7df2c79 ("Btrfs attach delayed ref updates to delayed ref heads"), check_delayed_ref() won't return -ENOENT. In btrfs_cross_ref_exist(), two variables 'ret' and 'ret2' are originally used to handle -ENOENT error case. Since the code is not needed anymore, let's just remove 'ret2'. Signed-off-by:
Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by:
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Liu Bo authored
Unless it's going to read inline extents from btree leaf to page, btrfs_get_extent won't sleep during the period of holding path lock. This sets leave_spinning at first and sets path to blocking mode right before reading inline extent if that's the case. The benefit is that a path in spinning mode typically has lower impact (faster) on waiters rather than that in the blocking mode. Signed-off-by:
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Liu Bo authored
This fixes btrfs_get_extent to be consistent with our existing declaration style. Note: For the record, indentation styles that are accepted are both, aligning under the opening ( and tab or double tab indentation on the next line. Preferrably not spliting the type or long expressions in the argument lists. Signed-off-by:
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