- 17 Dec, 2018 40 commits
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Josef Bacik authored
Traditionally we've had voodoo in btrfs to account for the space that delayed refs may take up by having a global_block_rsv. This works most of the time, except when it doesn't. We've had issues reported and seen in production where sometimes the global reserve is exhausted during transaction commit before we can run all of our delayed refs, resulting in an aborted transaction. Because of this voodoo we have equally dubious flushing semantics around throttling delayed refs which we often get wrong. So instead give them their own block_rsv. This way we can always know exactly how much outstanding space we need for delayed refs. This allows us to make sure we are constantly filling that reservation up with space, and allows us to put more precise pressure on the enospc system. Instead of doing math to see if its a good time to throttle, the normal enospc code will be invoked if we have a lot of delayed refs pending, and they will be run via the normal flushing mechanism. For now the delayed_refs_rsv will hold the reservations for the delayed refs, the block group updates, and deleting csums. We could have a separate rsv for the block group updates, but the csum deletion stuff is still handled via the delayed_refs so that will stay there. Historical background: The global reserve has grown to cover everything we don't reserve space explicitly for, and we've grown a lot of weird ad-hoc heuristics to know if we're running short on space and when it's time to force a commit. A failure rate of 20-40 file systems when we run hundreds of thousands of them isn't super high, but cleaning up this code will make things less ugly and more predictible. Thus the delayed refs rsv. We always know how many delayed refs we have outstanding, and although running them generates more we can use the global reserve for that spill over, which fits better into it's desired use than a full blown reservation. This first approach is to simply take how many times we're reserving space for and multiply that by 2 in order to save enough space for the delayed refs that could be generated. This is a niave approach and will probably evolve, but for now it works. Signed-off-by:
Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> # high-level review [ added background notes from the cover letter ] Signed-off-by:
David Sterba <dsterba@suse.com>
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Josef Bacik authored
We use this number to figure out how many delayed refs to run, but __btrfs_run_delayed_refs really only checks every time we need a new delayed ref head, so we always run at least one ref head completely no matter what the number of items on it. Fix the accounting to only be adjusted when we add/remove a ref head. In addition to using this number to limit the number of delayed refs run, a future patch is also going to use it to calculate the amount of space required for delayed refs space reservation. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
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Josef Bacik authored
The cleanup_extent_op function actually would run the extent_op if it needed running, which made the name sort of a misnomer. Change it to run_and_cleanup_extent_op, and move the actual cleanup work to cleanup_extent_op so it can be used by check_ref_cleanup() in order to unify the extent op handling. Reviewed-by:
Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by:
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Josef Bacik authored
We were missing some quota cleanups in check_ref_cleanup, so break the ref head accounting cleanup into a helper and call that from both check_ref_cleanup and cleanup_ref_head. This will hopefully ensure that we don't screw up accounting in the future for other things that we add. Reviewed-by:
Omar Sandoval <osandov@fb.com> Reviewed-by:
Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by:
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Josef Bacik authored
We do this dance in cleanup_ref_head and check_ref_cleanup, unify it into a helper and cleanup the calling functions. Reviewed-by:
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Johannes Thumshirn authored
When using a 'var & (PAGE_SIZE - 1)' construct one is checking for a page alignment and thus should use the PAGE_ALIGNED() macro instead of open-coding it. Convert all open-coded occurrences of PAGE_ALIGNED(). Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by:
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Johannes Thumshirn authored
Constructs like 'var & (PAGE_SIZE - 1)' or 'var & ~PAGE_MASK' can denote an offset into a page. So replace them by the offset_in_page() macro instead of open-coding it if they're not used as an alignment check. Reviewed-by:
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David Sterba authored
The dev-replace locking functions are now trivial wrappers around rw semaphore that can be used directly everywhere. No functional change. Signed-off-by: -
David Sterba authored
After the rw semaphore has been added, the custom blocking using ::blocking_readers and ::read_lock_wq is redundant. The blocking logic in __btrfs_map_block is replaced by extending the time the semaphore is held, that has the same blocking effect on writes as the previous custom scheme that waited until ::blocking_readers was zero. Signed-off-by: -
David Sterba authored
This is the first part of removing the custom locking and waiting scheme used for device replace. It was probably copied from extent buffer locking, but there's nothing that would require more than is provided by the common locking primitives. The rw spinlock protects waiting tasks counter in case of incompatible locks and the waitqueue. Same as rw semaphore. This patch only switches the locking primitive, for better bisectability. There should be no functional change other than the overhead of the locking and potential sleeping instead of spinning when the lock is contended. Signed-off-by: -
David Sterba authored
The device-replace read lock is going to use rw semaphore in followup commits. The semaphore might sleep which is not possible in the radix tree preload section. The lock nesting is now: * device replace * radix tree preload * readahead spinlock Signed-off-by: -
Nikolay Borisov authored
Running btrfs/124 in a loop hung up on me sporadically with the following call trace: btrfs D 0 5760 5324 0x00000000 Call Trace: ? __schedule+0x243/0x800 schedule+0x33/0x90 btrfs_start_ordered_extent+0x10c/0x1b0 [btrfs] ? wait_woken+0xa0/0xa0 btrfs_wait_ordered_range+0xbb/0x100 [btrfs] btrfs_relocate_block_group+0x1ff/0x230 [btrfs] btrfs_relocate_chunk+0x49/0x100 [btrfs] btrfs_balance+0xbeb/0x1740 [btrfs] btrfs_ioctl_balance+0x2ee/0x380 [btrfs] btrfs_ioctl+0x1691/0x3110 [btrfs] ? lockdep_hardirqs_on+0xed/0x180 ? __handle_mm_fault+0x8e7/0xfb0 ? _raw_spin_unlock+0x24/0x30 ? __handle_mm_fault+0x8e7/0xfb0 ? do_vfs_ioctl+0xa5/0x6e0 ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs] do_vfs_ioctl+0xa5/0x6e0 ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe ksys_ioctl+0x3a/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x49/0xbe This happens because during page writeback it's valid for writepage_delalloc to instantiate a delalloc range which doesn't belong to the page currently being written back. The reason this case is valid is due to find_lock_delalloc_range returning any available range after the passed delalloc_start and ignoring whether the page under writeback is within that range. In turn ordered extents (OE) are always created for the returned range from find_lock_delalloc_range. If, however, a failure occurs while OE are being created then the clean up code in btrfs_cleanup_ordered_extents will be called. Unfortunately the code in btrfs_cleanup_ordered_extents doesn't consider the case of such 'foreign' range being processed and instead it always assumes that the range OE are created for belongs to the page. This leads to the first page of such foregin range to not be cleaned up since it's deliberately missed and skipped by the current cleaning up code. Fix this by correctly checking whether the current page belongs to the range being instantiated and if so adjsut the range parameters passed for cleaning up. If it doesn't, then just clean the whole OE range directly. Fixes: 52427260 ("btrfs: Handle delalloc error correctly to avoid ordered extent hang") CC: stable@vger.kernel.org # 4.14+ Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
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Lu Fengqi authored
The @found is always false when it comes to the if branch. Besides, the bool type is more suitable for @found. Change the return value of the function and its caller to bool as well. Reviewed-by:
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Lu Fengqi authored
The test case btrfs/001 with inode_cache mount option will encounter the following warning: WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs] CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs] Call Trace: ? free_extent_buffer+0x46/0x90 [btrfs] run_delalloc_nocow+0x455/0x900 [btrfs] btrfs_run_delalloc_range+0x1a7/0x360 [btrfs] writepage_delalloc+0xf9/0x150 [btrfs] __extent_writepage+0x125/0x3e0 [btrfs] extent_write_cache_pages+0x1b6/0x3e0 [btrfs] ? __wake_up_common_lock+0x63/0xc0 extent_writepages+0x50/0x80 [btrfs] do_writepages+0x41/0xd0 ? __filemap_fdatawrite_range+0x9e/0xf0 __filemap_fdatawrite_range+0xbe/0xf0 btrfs_fdatawrite_range+0x1b/0x50 [btrfs] __btrfs_write_out_cache+0x42c/0x480 [btrfs] btrfs_write_out_ino_cache+0x84/0xd0 [btrfs] btrfs_save_ino_cache+0x551/0x660 [btrfs] commit_fs_roots+0xc5/0x190 [btrfs] btrfs_commit_transaction+0x2bf/0x8d0 [btrfs] btrfs_mksubvol+0x48d/0x4d0 [btrfs] btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs] btrfs_ioctl+0x123f/0x3030 [btrfs] The file extent generation of the free space inode is equal to the last snapshot of the file root, so the inode will be passed to cow_file_rage. But the inode was created and its extents were preallocated in btrfs_save_ino_cache, there are no cow copies on disk. The preallocated extent is not yet in the extent tree, and btrfs_cross_ref_exist will ignore the -ENOENT returned by check_committed_ref, so we can directly write the inode to the disk. Fixes: 78d4295b ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path") CC: stable@vger.kernel.org # 4.18+ Reviewed-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
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Filipe Manana authored
The log tree has a long standing problem that when a file is fsync'ed we only check for new ancestors, created in the current transaction, by following only the hard link for which the fsync was issued. We follow the ancestors using the VFS' dget_parent() API. This means that if we create a new link for a file in a directory that is new (or in an any other new ancestor directory) and then fsync the file using an old hard link, we end up not logging the new ancestor, and on log replay that new hard link and ancestor do not exist. In some cases, involving renames, the file will not exist at all. Example: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt mkdir /mnt/A touch /mnt/foo ln /mnt/foo /mnt/A/bar xfs_io -c fsync /mnt/foo <power failure> In this example after log replay only the hard link named 'foo' exists and directory A does not exist, which is unexpected. In other major linux filesystems, such as ext4, xfs and f2fs for example, both hard links exist and so does directory A after mounting again the filesystem. Checking if any new ancestors are new and need to be logged was added in 2009 by commit 12fcfd22 ("Btrfs: tree logging unlink/rename fixes"), however only for the ancestors of the hard link (dentry) for which the fsync was issued, instead of checking for all ancestors for all of the inode's hard links. So fix this by tracking the id of the last transaction where a hard link was created for an inode and then on fsync fallback to a full transaction commit when an inode has more than one hard link and at least one new hard link was created in the current transaction. This is the simplest solution since this is not a common use case (adding frequently hard links for which there's an ancestor created in the current transaction and then fsync the file). In case it ever becomes a common use case, a solution that consists of iterating the fs/subvol btree for each hard link and check if any ancestor is new, could be implemented. This solves many unexpected scenarios reported by Jayashree Mohan and Vijay Chidambaram, and for which there is a new test case for fstests under review. Fixes: 12fcfd22 ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Reported-by:
Vijay Chidambaram <vvijay03@gmail.com> Reported-by:
Jayashree Mohan <jayashree2912@gmail.com> Signed-off-by:
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David Sterba authored
The first auto-assigned value to enum is 0, we can use that and not initialize all members where the auto-increment does the same. This is used for values that are not part of on-disk format. Reviewed-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: ordered extent flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: extent map flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: extent buffer flags; Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: root tree flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: internal filesystem states. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: block reserve types. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: global filesystem states. Reviewed-by:
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Nikolay Borisov authored
This function really checks whether adding more data to the bio will straddle a stripe/chunk. So first let's give it a more appropraite name - btrfs_bio_fits_in_stripe. Secondly, the offset parameter was never used to just remove it. Thirdly, pages are submitted to either btree or data inodes so it's guaranteed that tree->ops is set so replace the check with an ASSERT. Finally, document the parameters of the function. No functional changes. Signed-off-by:
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Lu Fengqi authored
When it was introduced in commit f094ac32 ("Btrfs: fix NULL pointer after aborting a transaction"), it was not used. Signed-off-by:
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Johannes Thumshirn authored
Document why map_private_extent_buffer() cannot return '1' (i.e. the map spans two pages) for the csum_tree_block() case. The current algorithm for detecting a page boundary crossing in map_private_extent_buffer() will return a '1' *IFF* the extent buffer's offset in the page + the offset passed in by csum_tree_block() and the minimal length passed in by csum_tree_block() - 1 are bigger than PAGE_SIZE. We always pass BTRFS_CSUM_SIZE (32) as offset and a minimal length of 32 and the current extent buffer allocator always guarantees page aligned extends, so the above condition can't be true. Reviewed-by:
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Johannes Thumshirn authored
In map_private_extent_buffer() the 'offset' variable is initialized to a page aligned version of the 'start' parameter. But later on it is overwritten with either the offset from the extent buffer's start or 0. So get rid of the initial initialization. Reviewed-by:
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Filipe Manana authored
When a transaction commit starts, it attempts to pause scrub and it blocks until the scrub is paused. So while the transaction is blocked waiting for scrub to pause, we can not do memory allocation with GFP_KERNEL from scrub, otherwise we risk getting into a deadlock with reclaim. Checking for scrub pause requests is done early at the beginning of the while loop of scrub_stripe() and later in the loop, scrub_extent() and scrub_raid56_parity() are called, which in turn call scrub_pages() and scrub_pages_for_parity() respectively. These last two functions do memory allocations using GFP_KERNEL. Same problem could happen while scrubbing the super blocks, since it calls scrub_pages(). We also can not have any of the worker tasks, created by the scrub task, doing GFP_KERNEL allocations, because before pausing, the scrub task waits for all the worker tasks to complete (also done at scrub_stripe()). So make sure GFP_NOFS is used for the memory allocations because at any time a scrub pause request can happen from another task that started to commit a transaction. Fixes: 58c4e173 ("btrfs: scrub: use GFP_KERNEL on the submission path") CC: stable@vger.kernel.org # 4.6+ Reviewed-by:
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Nikolay Borisov authored
For data inodes this hook does nothing but to return -EAGAIN which is used to signal to the endio routines that this bio belongs to a data inode. If this is the case the actual retrying is handled by bio_readpage_error. Alternatively, if this bio belongs to the btree inode then btree_io_failed_hook just does some cleanup and doesn't retry anything. This patch simplifies the code flow by eliminating readpage_io_failed_hook and instead open-coding btree_io_failed_hook in end_bio_extent_readpage. Also eliminate some needless checks since IO is always performed on either data inode or btree inode, both of which are guaranteed to have their extent_io_tree::ops set. Signed-off-by:
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Johannes Thumshirn authored
The btrfs_bio_end_io_t typedef was introduced with commit a1d3c478 ("btrfs: btrfs_multi_bio replaced with btrfs_bio") but never used anywhere. This commit also introduced a forward declaration of 'struct btrfs_bio' which is only needed for btrfs_bio_end_io_t. Remove both as they're not needed anywhere. Reviewed-by:
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David Sterba authored
The end_io callback implemented as btrfs_io_bio_endio_readpage only calls kfree. Also the callback is set only in case the csum buffer is allocated and not pointing to the inline buffer. We can use that information to drop the indirection and call a helper that will free the csums only in the right case. This shrinks struct btrfs_io_bio by 8 bytes. Reviewed-by:
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David Sterba authored
The io_bio tracks checksums and has an inline buffer or an allocated one. And there's a third member that points to the right one, but we don't need to use an extra pointer for that. Let btrfs_io_bio::csum point to the right buffer and check that the inline buffer is not accidentally freed. This shrinks struct btrfs_io_bio by 8 bytes. Reviewed-by:
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David Sterba authored
The async_cow::root is used to propagate fs_info to async_cow_submit. We can't use inode to reach it because it could become NULL after write without compression in async_cow_start. Reviewed-by:
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David Sterba authored
There's one caller and its code is simple, we can open code it in run_one_async_done. The errors are passed through bio. Reviewed-by:
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Anand Jain authored
Print a kernel log message when the balance ends, either for cancel or completed or if it is paused. Signed-off-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
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Anand Jain authored
The information about balance arguments is important for system audit, this patch prints the textual representation when balance starts or is resumed. Example command: $ btrfs balance start -f -mprofiles=raid1,convert=single,soft -dlimit=10..20,usage=50 /btrfs Example kernel log output: BTRFS info (device sdb): balance: start -f -dusage=50,limit=10..20 -mconvert=single,soft,profiles=raid1 -sconvert=single,soft,profiles=raid1 Signed-off-by:
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Anand Jain authored
Factor out helper that describes block group flags from describe_relocation. The result will not be longer than the given size. Signed-off-by:
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Filipe Manana authored
If the quota enable and snapshot creation ioctls are called concurrently we can get into a deadlock where the task enabling quotas will deadlock on the fs_info->qgroup_ioctl_lock mutex because it attempts to lock it twice, or the task creating a snapshot tries to commit the transaction while the task enabling quota waits for the former task to commit the transaction while holding the mutex. The following time diagrams show how both cases happen. First scenario: CPU 0 CPU 1 btrfs_ioctl() btrfs_ioctl_quota_ctl() btrfs_quota_enable() mutex_lock(fs_info->qgroup_ioctl_lock) btrfs_start_transaction() btrfs_ioctl() btrfs_ioctl_snap_create_v2 create_snapshot() --> adds snapshot to the list pending_snapshots of the current transaction btrfs_commit_transaction() create_pending_snapshots() create_pending_snapshot() qgroup_account_snapshot() btrfs_qgroup_inherit() mutex_lock(fs_info->qgroup_ioctl_lock) --> deadlock, mutex already locked by this task at btrfs_quota_enable() Second scenario: CPU 0 CPU 1 btrfs_ioctl() btrfs_ioctl_quota_ctl() btrfs_quota_enable() mutex_lock(fs_info->qgroup_ioctl_lock) btrfs_start_transaction() btrfs_ioctl() btrfs_ioctl_snap_create_v2 create_snapshot() --> adds snapshot to the list pending_snapshots of the current transaction btrfs_commit_transaction() --> waits for task at CPU 0 to release its transaction handle btrfs_commit_transaction() --> sees another task started the transaction commit first --> releases its transaction handle --> waits for the transaction commit to be completed by the task at CPU 1 create_pending_snapshot() qgroup_account_snapshot() btrfs_qgroup_inherit() mutex_lock(fs_info->qgroup_ioctl_lock) --> deadlock, task at CPU 0 has the mutex locked but it is waiting for us to finish the transaction commit So fix this by setting the quota enabled flag in fs_info after committing the transaction at btrfs_quota_enable(). This ends up serializing quota enable and snapshot creation as if the snapshot creation happened just before the quota enable request. The quota rescan task, scheduled after committing the transaction in btrfs_quote_enable(), will do the accounting. Fixes: 6426c7ad ("btrfs: qgroup: Fix qgroup accounting when creating snapshot") Signed-off-by: -
Filipe Manana authored
The available allocation bits members from struct btrfs_fs_info are protected by a sequence lock, and when starting balance we access them incorrectly in two different ways: 1) In the read sequence lock loop at btrfs_balance() we use the values we read from fs_info->avail_*_alloc_bits and we can immediately do actions that have side effects and can not be undone (printing a message and jumping to a label). This is wrong because a retry might be needed, so our actions must not have side effects and must be repeatable as long as read_seqretry() returns a non-zero value. In other words, we were essentially ignoring the sequence lock; 2) Right below the read sequence lock loop, we were reading the values from avail_metadata_alloc_bits and avail_data_alloc_bits without any protection from concurrent writers, that is, reading them outside of the read sequence lock critical section. So fix this by making sure we only read the available allocation bits while in a read sequence lock critical section and that what we do in the critical section is repeatable (has nothing that can not be undone) so that any eventual retry that is needed is handled properly. Fixes: de98ced9 ("Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits") Fixes: 14506127 ("btrfs: fix a bogus warning when converting only data or metadata") Reviewed-by:
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Filipe Manana authored
We can have a lot freed extents during the life span of transaction, so the red black tree that keeps track of the ranges of each freed extent (fs_info->freed_extents[]) can get quite big. When finishing a transaction commit we find each range, process it (discard the extents, unpin them) and then remove it from the red black tree. We can use an extent state record as a cache when searching for a range, so that when we clean the range we can use the cached extent state we passed to the search function instead of iterating the red black tree again. Doing things as fast as possible when finishing a transaction (in state TRANS_STATE_UNBLOCKED) is convenient as it reduces the time we block another task that wants to commit the next transaction. So change clear_extent_dirty() to allow an optional extent state record to be passed as an argument, which will be passed down to __clear_extent_bit. Reviewed-by:
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