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path: root/fs/btrfs/extent-tree.c
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2024-01-18btrfs: don't warn if discard range is not aligned to sectorDavid Sterba
There's a warning in btrfs_issue_discard() when the range is not aligned to 512 bytes, originally added in 4d89d377bbb0 ("btrfs: btrfs_issue_discard ensure offset/length are aligned to sector boundaries"). We can't do sub-sector writes anyway so the adjustment is the only thing that we can do and the warning is unnecessary. CC: stable@vger.kernel.org # 4.19+ Reported-by: syzbot+4a4f1eba14eb5c3417d1@syzkaller.appspotmail.com Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-01-12btrfs: zoned: optimize hint byte for zoned allocatorNaohiro Aota
Writing sequentially to a huge file on btrfs on a SMR HDD revealed a decline of the performance (220 MiB/s to 30 MiB/s after 500 minutes). The performance goes down because of increased latency of the extent allocation, which is induced by a traversing of a lot of full block groups. So, this patch optimizes the ffe_ctl->hint_byte by choosing a block group with sufficient size from the active block group list, which does not contain full block groups. After applying the patch, the performance is maintained well. Fixes: 2eda57089ea3 ("btrfs: zoned: implement sequential extent allocation") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-01-12btrfs: zoned: factor out prepare_allocation_zoned()Naohiro Aota
Factor out prepare_allocation_zoned() for further extension. While at it, optimize the if-branch a bit. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-15btrfs: reflow btrfs_free_tree_blockJohannes Thumshirn
Reflow btrfs_free_tree_block() so that there is one level of indentation needed. This patch has no functional changes. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-15btrfs: remove now unneeded btrfs_redirty_list_addJohannes Thumshirn
Now that we're not clearing the dirty flag off of extent_buffers in zoned mode, all that is left of btrfs_redirty_list_add() is a memzero() and some ASSERT()ions. As we're also memzero()ing the buffer on write-out btrfs_redirty_list_add() has become obsolete and can be removed. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-15btrfs: rename EXTENT_BUFFER_NO_CHECK to EXTENT_BUFFER_ZONED_ZEROOUTJohannes Thumshirn
EXTENT_BUFFER_ZONED_ZEROOUT better describes the state of the extent buffer, namely it is written as all zeros. This is needed in zoned mode, to preserve I/O ordering. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-06btrfs: ensure releasing squota reserve on head refsBoris Burkov
A reservation goes through a 3 step lifetime: - generated during delalloc - released/counted by ordered_extent allocation - freed by running delayed ref That third step depends on must_insert_reserved on the head ref, so the head ref with that field set owns the reservation. Once you prepare to run the head ref, must_insert_reserved is unset, which means that running the ref must free the reservation, whether or not it succeeds, or else the reservation is leaked. That results in either a risk of spurious ENOSPC if the fs stays writeable or a warning on unmount if it is readonly. The existing squota code was aware of these invariants, but missed a few cases. Improve it by adding a helper function to use in the cleanup paths and call it from the existing early returns in running delayed refs. This also simplifies btrfs_record_squota_delta and struct btrfs_quota_delta. This fixes (or at least improves the reliability of) generic/475 with "mkfs -O squota". On my machine, that test failed ~4/10 times without this patch and passed 100/100 times with it. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-11-03btrfs: get correct owning_root when dropping snapshotJosef Bacik
Dave reported a bug where we were aborting the transaction while trying to cleanup the squota reservation for an extent. This turned out to be because we're doing btrfs_header_owner(next) in do_walk_down when we decide to free the block. However in this code block we haven't explicitly read next, so it could be stale. We would then get whatever garbage happened to be in the pages at this point. The commit that introduced that is "btrfs: track owning root in btrfs_ref". Fix this by saving the owner_root when we do the btrfs_lookup_extent_info(). We always do this in do_walk_down, it is how we make the decision of whether or not to delete the block. This is cheap because we've already done the extent item lookup at this point, so it's straightforward to just grab the owner root as well. Then we can use this when deleting the metadata block without needing to force a read of the extent buffer to find the owner. This fixes the problem that Dave reported. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: track data relocation with simple quotaBoris Burkov
Relocation data allocations are quite tricky for simple quotas. The basic data relocation sequence is (ignoring details that aren't relevant to this fix): - create a fake relocation data fs root - create a fake relocation inode in that root - for each data extent: - preallocate a data extent on behalf of the fake inode - copy over the data - for each extent - swap the refs so that the original file extent now refers to the new extent item - drop the fake root, dropping its refs on the old extents, which lets us delete them. Done naively, this results in storing an extent item in the extent tree whose owner_ref points at the relocation data root and a no-op squota recording, since the reloc root is not a legit fstree. So far, that's OK. The problem comes when you do the swap, and leave an extent item owned by this bogus root as the real permanent extents of the file. If the file then drops that ref, we free it and no-op account that against the fake relocation root. Essentially, this means that relocation is simple quota "extent laundering", since we re-own the extents into a fake root. Simple quotas very intentionally doesn't have a mechanism for transferring ownership of extents, as that is exactly the complicated thing we are trying to avoid with the new design. Further, it cannot be correctly done in this case, since at the time you create the new "real" refs, there is no way to know which was the original owner before relocation unless we track it. Therefore, it makes more sense to trick the preallocation to handle relocation as a special case and note the proper owner ref from the beginning. That way, we never write out an extent item without the correct owner ref that it will eventually have. This could be done by wiring a special root parameter all the way through the allocation code path, but to avoid that special case touching all the code, take advantage of the serial nature of relocation to store the src root on the relocation root object. Then when we finish the prealloc, if it happens to be this case, prepare the delayed ref appropriately. We must also add logic to handle relocating adjacent extents with different owning roots. Those cannot be preallocated together in a cluster as it would lose the separate ownership information. This is obviously a smelly bit of code, but I think it is the best solution to the problem, given the relocation implementation. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: qgroup: track metadata relocation COW with simple quotaBoris Burkov
Relocation COWs metadata blocks in two cases for the reloc root: - copying the subvolume root item when creating the reloc root - copying a btree node when there is a COW during relocation In both cases, the resulting btree node hits an abnormal code path with respect to the owner field in its btrfs_header. It first creates the root item for the new objectid, which populates the reloc root id, and it at this point that delayed refs are created. Later, it fully copies the old node into the new node (including the original owner field) which overwrites it. This results in a simple quotas mismatch where we run the delayed ref for the reloc root which has no simple quota effect (reloc root is not an fstree) but when we ultimately delete the node, the owner is the real original fstree and we do free the space. To work around this without tampering with the behavior of relocation, add a parameter to btrfs_add_tree_block that lets the relocation code path specify a different owning root than the "operating" root (in this case, owning root is the real root and the operating root is the reloc root). These can naturally be plumbed into delayed refs that have the same concept. Note that this is a double count in some sense, but a relatively natural one, as there are really two extents, and the old one will be deleted soon. This is consistent with how data relocation extents are accounted by simple quotas. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: qgroup: check generation when recording simple quota deltaBoris Burkov
Simple quotas count extents only from the moment the feature is enabled. Therefore, if we do something like: 1. create subvol S 2. write F in S 3. enable quotas 4. remove F 5. write G in S then after 3. and 4. we would expect the simple quota usage of S to be 0 (putting aside some metadata extents that might be written) and after 5., it should be the size of G plus metadata. Therefore, we need to be able to determine whether a particular quota delta we are processing predates simple quota enablement. To do this, store the transaction id when quotas were enabled. In fs_info for immediate use and in the quota status item to make it recoverable on mount. When we see a delta, check if the generation of the extent item is less than that of quota enablement. If so, we should ignore the delta from this extent. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: record simple quota deltas in delayed refsBoris Burkov
At the moment that we run delayed refs, we make the final ref-count based decision on creating/removing extent (and metadata) items. Therefore, it is exactly the spot to hook up simple quotas. There are a few important subtleties to the fields we must collect to accurately track simple quotas, particularly when removing an extent. When removing a data extent, the ref could be in any tree (due to reflink, for example) and so we need to recover the owning root id from the owner ref item. When removing a metadata extent, we know the owning root from the owner field in the header when we create the delayed ref, so we can recover it from there. We must also be careful to handle reservations properly to not leaked reserved space. The happy path is freeing the reservation when the simple quota delta runs on a data extent. If that doesn't happen, due to refs canceling out or some error, the ref head already has the must_insert_reserved machinery to handle this, so we piggy back on that and use it to clean up the reserved data. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: add helper for inline owner ref lookupBoris Burkov
Inline ref parsing is a bit tricky and relies on a decent amount of implicit information, so I think it is beneficial to have a helper function for reading the owner ref, if only to "document" the format, along with the write path. The main subtlety of note which I was missing by open-coding this was that it is important to check whether or not inline refs are present *at all*. i.e., if we are writing out a new extent under squotas, we will always use a big enough item for the inline ref and have it. However, it is possible that some random item predating squotas will not have any inline refs. In that case, trying to read the "type" field of the first inline ref will just be reading garbage in the form of whatever is in the next item. This will be used by the extent free-ing path, which looks up data extent owners as well as a relocation path which needs to grab the owner before relocating an extent. Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: new inline ref storing owning subvol of data extentsBoris Burkov
In order to implement simple quota groups, we need to be able to associate a data extent with the subvolume that created it. Once you account for reflink, this information cannot be recovered without explicitly storing it. Options for storing it are: - a new key/item - a new extent inline ref item The former is backwards compatible, but wastes space, the latter is incompat, but is efficient in space and reuses the existing inline ref machinery, while only abusing it a tiny amount -- specifically, the new item is not a ref, per-se. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: track owning root in btrfs_refBoris Burkov
While data extents require us to store additional inline refs to track the original owner on free, this information is available implicitly for metadata. It is found in the owner field of the header of the tree block. Even if other trees refer to this block and the original ref goes away, we will not rewrite that header field, so it will reliably give the original owner. In addition, there is a relocation case where a new data extent needs to have an owning root separate from the referring root wired through delayed refs. To use it for recording simple quota deltas, we need to wire this root id through from when we create the delayed ref until we fully process it. Store it in the generic btrfs_ref struct of the delayed ref. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: rename tree_ref and data_ref owning_rootBoris Burkov
commit 113479d5b8eb ("btrfs: rename root fields in delayed refs structs") changed these from ref_root to owning_root. However, there are many circumstances where that name is not really accurate and the root on the ref struct _is_ the referring root. In general, these are not the owning root, though it does happen in some ref merging cases involving overwrites during snapshots and similar. Simple quotas cares quite a bit about tracking the original owner of an extent through delayed refs, so rename these back to free up the name for the real owning root (which will live on the generic btrfs_ref and the head ref) Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: delete stripe extent on extent deletionJohannes Thumshirn
As each stripe extent is tied to an extent item, delete the stripe extent once the corresponding extent item is deleted. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: add support for inserting raid stripe extentsJohannes Thumshirn
Add support for inserting stripe extents into the raid stripe tree on completion of every write that needs an extra logical-to-physical translation when using RAID. Inserting the stripe extents happens after the data I/O has completed, this is done to a) support zone-append and b) rule out the possibility of a RAID-write-hole. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove useless comment from btrfs_pin_extent_for_log_replay()Filipe Manana
The comment on top of btrfs_pin_extent_for_log_replay() mentioning that the function must be called within a transaction is pointless as of commit 9fce5704542c ("btrfs: Make btrfs_pin_extent_for_log_replay take transaction handle"), since the function now takes a transaction handle as its first argument. So remove the comment because it's completely useless now. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove stale comment from btrfs_free_extent()Filipe Manana
A comment at btrfs_free_extent() mentions the call to btrfs_pin_extent() unlocks the pinned mutex, however that mutex is long gone, it was removed in 2009 by commit 04018de5d41e ("Btrfs: kill the pinned_mutex"). So just delete the comment. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: abort transaction on generation mismatch when marking eb as dirtyFilipe Manana
When marking an extent buffer as dirty, at btrfs_mark_buffer_dirty(), we check if its generation matches the running transaction and if not we just print a warning. Such mismatch is an indicator that something really went wrong and only printing a warning message (and stack trace) is not enough to prevent a corruption. Allowing a transaction to commit with such an extent buffer will trigger an error if we ever try to read it from disk due to a generation mismatch with its parent generation. So abort the current transaction with -EUCLEAN if we notice a generation mismatch. For this we need to pass a transaction handle to btrfs_mark_buffer_dirty() which is always available except in test code, in which case we can pass NULL since it operates on dummy extent buffers and all test roots have a single node/leaf (root node at level 0). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: stop doing excessive space reservation for csum deletionFilipe Manana
Currently when reserving space for deleting the csum items for a data extent, when adding or updating a delayed ref head, we determine how many leaves of csum items we can have and then pass that number to the helper btrfs_calc_delayed_ref_bytes(). This helper is used for calculating space for all tree modifications we need when running delayed references, however the amount of space it computes is excessive for deleting csum items because: 1) It uses btrfs_calc_insert_metadata_size() which is excessive because we only need to delete csum items from the csum tree, we don't need to insert any items, so btrfs_calc_metadata_size() is all we need (as it computes space needed to delete an item); 2) If the free space tree is enabled, it doubles the amount of space, which is pointless for csum deletion since we don't need to touch the free space tree or any other tree other than the csum tree. So improve on this by tracking how many csum deletions we have and using a new helper to calculate space for csum deletions (just a wrapper around btrfs_calc_metadata_size() with a comment). This reduces the amount of space we need to reserve for csum deletions by a factor of 4, and it helps reduce the number of times we have to block space reservations and have the reclaim task enter the space flushing algorithm (flush delayed items, flush delayed refs, etc) in order to satisfy tickets. For example this results in a total time decrease when unlinking (or truncating) files with many extents, as we end up having to block on space metadata reservations less often. Example test: $ cat test.sh #!/bin/bash DEV=/dev/nullb0 MNT=/mnt/test umount $DEV &> /dev/null mkfs.btrfs -f $DEV # Use compression to quickly create files with a lot of extents # (each with a size of 128K). mount -o compress=lzo $DEV $MNT # 100G gives at least 983040 extents with a size of 128K. xfs_io -f -c "pwrite -S 0xab -b 1M 0 120G" $MNT/foobar # Flush all delalloc and clear all metadata from memory. umount $MNT mount -o compress=lzo $DEV $MNT start=$(date +%s%N) rm -f $MNT/foobar end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo "rm took $dur milliseconds" umount $MNT Before this change rm took: 7504 milliseconds After this change rm took: 6574 milliseconds (-12.4%) Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: reserve space for delayed refs on a per ref basisFilipe Manana
Currently when reserving space for delayed refs we do it on a per ref head basis. This is generally enough because most back refs for an extent end up being inlined in the extent item - with the default leaf size of 16K we can have at most 33 inline back refs (this is calculated by the macro BTRFS_MAX_EXTENT_ITEM_SIZE()). The amount of bytes reserved for each ref head is given by btrfs_calc_delayed_ref_bytes(), which basically corresponds to a single path for insertion into the extent tree plus another path for insertion into the free space tree if it's enabled. However if we have reached the limit of inline refs or we have a mix of inline and non-inline refs, then we will need to insert a non-inline ref and update the existing extent item to update the total number of references for the extent. This implies we need reserved space for two insertion paths in the extent tree, but we only reserved for one path. The extent item and the non-inline ref item may be located in different leaves, or even if they are located in the same leaf, after updating the extent item and before inserting the non-inline ref item, the extent buffers in the btree path may have been written (due to memory pressure for e.g.), in which case we need to COW the entire path again. In this case since we have not reserved enough space for the delayed refs block reserve, we will use the global block reserve. If we are in a situation where the fs has no more unallocated space enough to allocate a new metadata block group and available space in the existing metadata block groups is close to the maximum size of the global block reserve (512M), we may end up consuming too much of the free metadata space to the point where we can't commit any future transaction because it will fail, with -ENOSPC, during its commit when trying to allocate an extent for some COW operation (running delayed refs generated by running delayed refs or COWing the root tree's root node at commit_cowonly_roots() for example). Such dramatic scenario can happen if we have many delayed refs that require the insertion of non-inline ref items, due to too many reflinks or snapshots. We also have situations where we use the global block reserve because we could not in advance know that we will need space to update some trees (block group creation for example), so this all adds up to increase the chances of exhausting the global block reserve and making any future transaction commit to fail with -ENOSPC and turn the fs into RO mode, or fail the mount operation in case the mount needs to start and commit a transaction, such as when we have orphans to cleanup for example - such case was reported and hit by someone running a SLE (SUSE Linux Enterprise) distribution for example - where the fs had no more unallocated space that could be used to allocate a new metadata block group, and the available metadata space was about 1.5M, not enough to commit a transaction to cleanup an orphan inode (or do relocation of data block groups that were far from being full). So reserve space for delayed refs by individual refs and not by ref heads, as we may need to COW multiple extent tree paths due to non-inline ref items. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: allow to run delayed refs by bytes to be released instead of countFilipe Manana
When running delayed references, through btrfs_run_delayed_refs(), we can specify how many to run, run all existing delayed references and keep running delayed references while we can find any. This is controlled with the value of the 'count' argument, where a value of 0 means to run all delayed references that exist by the time btrfs_run_delayed_refs() is called, (unsigned long)-1 means to keep running delayed references while we are able find any, and any other value to run that exact number of delayed references. Typically a specific value other than 0 or -1 is used when flushing space to try to release a certain amount of bytes for a ticket. In this case we just simply calculate how many delayed reference heads correspond to a specific amount of bytes, with calc_delayed_refs_nr(). However that only takes into account the space reserved for the reference heads themselves, and does not account for the space reserved for deleting checksums from the csum tree (see add_delayed_ref_head() and update_existing_head_ref()) in case we are going to delete a data extent. This means we may end up running more delayed references than necessary in case we process delayed references for deleting a data extent. So change the logic of btrfs_run_delayed_refs() to take a bytes argument to specify how many bytes of delayed references to run/release, using the special values of 0 to mean all existing delayed references and U64_MAX (or (u64)-1) to keep running delayed references while we can find any. This prevents running more delayed references than necessary, when we have delayed references for deleting data extents, but also makes the upcoming changes/patches simpler and it's preparatory work for them. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: simplify check for extent item overrun at lookup_inline_extent_backref()Filipe Manana
At lookup_inline_extent_backref() we can simplify the check for an overrun of the extent item by making the while loop's condition to be "ptr < end" and then check after the loop if an overrun happened ("ptr > end"). This reduces indentation and makes the loop condition more clear. So move the check out of the loop and change the loop condition accordingly, while also adding the 'unlikely' tag to the check since it's not supposed to be triggered. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: return -EUCLEAN if extent item is missing when searching inline backrefFilipe Manana
At lookup_inline_extent_backref() when trying to insert an inline backref, if we don't find the extent item we log an error and then return -EIO. This error code is confusing because there was actually no IO error, and this means we have some corruption, either caused by a bug or something like a memory bitflip for example. So change the error code from -EIO to -EUCLEAN. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: use a single variable for return value at lookup_inline_extent_backref()Filipe Manana
At lookup_inline_extent_backref(), instead of using a 'ret' and an 'err' variable for tracking the return value, use a single one ('ret'). This simplifies the code, makes it comply with most of the existing code and it's less prone for logic errors as time has proven over and over in the btrfs code. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: use a single variable for return value at run_delayed_extent_op()Filipe Manana
Instead of using a 'ret' and an 'err' variable at run_delayed_extent_op() for tracking the return value, use a single one ('ret'). This simplifies the code, makes it comply with most of the existing code and it's less prone for logic errors as time has proven over and over in the btrfs code. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove pointless 'ref_root' variable from run_delayed_data_ref()Filipe Manana
The 'ref_root' variable, at run_delayed_data_ref(), is not really needed as we can always use ref->root directly, plus its initialization to 0 is completely pointless as we assign it ref->root before its first use. So just drop that variable and use ref->root directly. This may help avoid some warnings with clang tools such as the one reported/fixed by commit 966de47ff0c9 ("btrfs: remove redundant initialization of variables in log_new_ancestors"). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: initialize key where it's used when running delayed data refFilipe Manana
At run_delayed_data_ref() we are always initializing a key but the key is only needed and used if we are inserting a new extent. So move the declaration and initialization of the key to 'if' branch where it's used. Also rename the key from 'ins' to 'key', as it's a more clear name. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove refs_to_drop argument from __btrfs_free_extent()Filipe Manana
Currently the 'refs_to_drop' argument of __btrfs_free_extent() always matches the value of node->ref_mod, so remove the argument and use node->ref_mod at __btrfs_free_extent(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove refs_to_add argument from __btrfs_inc_extent_ref()Filipe Manana
Currently the 'refs_to_add' argument of __btrfs_inc_extent_ref() always matches the value of node->ref_mod, so remove the argument and use node->ref_mod at __btrfs_inc_extent_ref(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove unnecessary logic when running new delayed referencesFilipe Manana
When running delayed references, at btrfs_run_delayed_refs(), we have this logic to run any new delayed references that might have been added just after we ran all delayed references. This logic grabs the first delayed reference, then locks it to wait for any contention on it before running all new delayed references. This however is pointless and not necessary because at __btrfs_run_delayed_refs() when we start running delayed references, we pick the first reference with btrfs_obtain_ref_head() and then we will lock it (with btrfs_delayed_ref_lock()). So remove the duplicate and unnecessary logic at btrfs_run_delayed_refs(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: move extent_buffer::lock_owner to debug sectionDavid Sterba
The lock_owner is used for a rare corruption case and we haven't seen any reports in years. Move it to the debugging section of eb. To close the holes also move log_index so the final layout looks like: struct extent_buffer { u64 start; /* 0 8 */ long unsigned int len; /* 8 8 */ long unsigned int bflags; /* 16 8 */ struct btrfs_fs_info * fs_info; /* 24 8 */ spinlock_t refs_lock; /* 32 4 */ atomic_t refs; /* 36 4 */ int read_mirror; /* 40 4 */ s8 log_index; /* 44 1 */ /* XXX 3 bytes hole, try to pack */ struct callback_head callback_head __attribute__((__aligned__(8))); /* 48 16 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct rw_semaphore lock; /* 64 40 */ struct page * pages[16]; /* 104 128 */ /* size: 232, cachelines: 4, members: 11 */ /* sum members: 229, holes: 1, sum holes: 3 */ /* forced alignments: 1, forced holes: 1, sum forced holes: 3 */ /* last cacheline: 40 bytes */ } __attribute__((__aligned__(8))); This saves 8 bytes in total and still keeps the lock on a separate cacheline. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: reduce parameters of btrfs_pin_extent_for_log_replayDavid Sterba
Both callers of btrfs_pin_extent_for_log_replay expand the parameters to extent buffer members. We can simply pass the extent buffer instead. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: reduce parameters of btrfs_pin_reserved_extentDavid Sterba
There is only one caller of btrfs_pin_reserved_extent that expands the parameters to extent buffer members. We can simply pass the extent buffer instead. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: reformat remaining kdoc style commentsDavid Sterba
Function name in the comment does not bring much value to code not exposed as API and we don't stick to the kdoc format anymore. Update formatting of parameter descriptions. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12btrfs: remove btrfs_crc32c wrapperJosef Bacik
This simply sends the same arguments into crc32c(), and is just used in a few places. Remove this wrapper and directly call crc32c() in these instances. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-09-20btrfs: log message if extent item not found when running delayed extent opFilipe Manana
When running a delayed extent operation, if we don't find the extent item in the extent tree we just return -EIO without any logged message. This indicates some bug or possibly a memory or fs corruption, so the return value should not be -EIO but -EUCLEAN instead, and since it's not expected to ever happen, print an informative error message so that if it happens we have some idea of what went wrong, where to look at. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-09-20btrfs: remove redundant BUG_ON() from __btrfs_inc_extent_ref()Filipe Manana
At __btrfs_inc_extent_ref() we are doing a BUG_ON() if we are dealing with a tree block reference that has a reference count that is different from 1, but we have already dealt with this case at run_delayed_tree_ref(), making it useless. So remove the BUG_ON(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-09-20btrfs: return -EUCLEAN for delayed tree ref with a ref count not equals to 1Filipe Manana
When running a delayed tree reference, if we find a ref count different from 1, we return -EIO. This isn't an IO error, as it indicates either a bug in the delayed refs code or a memory corruption, so change the error code from -EIO to -EUCLEAN. Also tag the branch as 'unlikely' as this is not expected to ever happen, and change the error message to print the tree block's bytenr without the parenthesis (and there was a missing space between the 'block' word and the opening parenthesis), for consistency as that's the style we used everywhere else. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: remove v0 extent handlingQu Wenruo
The v0 extent item has been deprecated for a long time, and we don't have any report from the community either. So it's time to remove the v0 extent specific error handling, and just treat them as regular extent tree corruption. This patch would remove the btrfs_print_v0_err() helper, and enhance the involved error handling to treat them just as any extent tree corruption. No reports regarding v0 extents have been seen since the graceful handling was added in 2018. This involves: - btrfs_backref_add_tree_node() This change is a little tricky, the new code is changed to only handle BTRFS_TREE_BLOCK_REF_KEY and BTRFS_SHARED_BLOCK_REF_KEY. But this is safe, as we have rejected any unknown inline refs through btrfs_get_extent_inline_ref_type(). For keyed backrefs, we're safe to skip anything we don't know (that's if it can pass tree-checker in the first place). - btrfs_lookup_extent_info() - lookup_inline_extent_backref() - run_delayed_extent_op() - __btrfs_free_extent() - add_tree_block() Regular error handling of unexpected extent tree item, and abort transaction (if we have a trans handle). - remove_extent_data_ref() It's pretty much the same as the regular rejection of unknown backref key. But for this particular case, we can also remove a BUG_ON(). - extent_data_ref_count() We can remove the BTRFS_EXTENT_REF_V0_KEY BUG_ON(), as it would be rejected by the only caller. - btrfs_print_leaf() Remove the handling for BTRFS_EXTENT_REF_V0_KEY. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: output extra debug info if we failed to find an inline backrefQu Wenruo
[BUG] Syzbot reported several warning triggered inside lookup_inline_extent_backref(). [CAUSE] As usual, the reproducer doesn't reliably trigger locally here, but at least we know the WARN_ON() is triggered when an inline backref can not be found, and it can only be triggered when @insert is true. (I.e. inserting a new inline backref, which means the backref should already exist) [ENHANCEMENT] After the WARN_ON(), dump all the parameters and the extent tree leaf to help debug. Link: https://syzkaller.appspot.com/bug?extid=d6f9ff86c1d804ba2bc6 Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: zoned: do not zone finish data relocation block groupNaohiro Aota
When multiple writes happen at once, we may need to sacrifice a currently active block group to be zone finished for a new allocation. We choose a block group with the least free space left, and zone finish it. To do the finishing, we need to send IOs for already allocated region and wait for them and on-going IOs. Otherwise, these IOs fail because the zone is already finished at the time the IO reach a device. However, if a block group dedicated to the data relocation is zone finished, there is a chance that finishing it before an ongoing write IO reaches the device. That is because there is timing gap between an allocation is done (block_group->reservations == 0, as pre-allocation is done) and an ordered extent is created when the relocation IO starts. Thus, if we finish the zone between them, we can fail the IOs. We cannot simply use "fs_info->data_reloc_bg == block_group->start" to avoid the zone finishing. Because, the data_reloc_bg may already switch to a new block group, while there are still ongoing write IOs to the old data_reloc_bg. So, this patch reworks the BLOCK_GROUP_FLAG_ZONED_DATA_RELOC bit to indicate there is a data relocation allocation and/or ongoing write to the block group. The bit is set on allocation and cleared in end_io function of the last IO for the currently allocated region. To change the timing of the bit setting also solves the issue that the bit being left even after there is no IO going on. With the current code, if the data_reloc_bg switches after the last IO to the current data_reloc_bg, the bit is set at this timing and there is no one clearing that bit. As a result, that block group is kept unallocatable for anything. Fixes: 343d8a30851c ("btrfs: zoned: prevent allocation from previous data relocation BG") Fixes: 74e91b12b115 ("btrfs: zoned: zone finish unused block group") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: wait on uncached block groups on every allocation loopJosef Bacik
My initial fix for the generic/475 hangs was related to metadata, but our CI testing uncovered another case where we hang for similar reasons. We again have a task with a plug that is holding an outstanding request that is keeping the dm device from finishing it's suspend, and that task is stuck in the allocator. This time it is stuck trying to allocate data, but we do not have a block group that matches the size class. The larger loop in the allocator looks like this (simplified of course) find_free_extent for_each_block_group { ffe_ctl->cached == btrfs_block_group_cache_done(bg) if (!ffe_ctl->cached) ffe_ctl->have_caching_bg = true; do_allocation() btrfs_wait_block_group_cache_progress(); } if (loop == LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg) go search again; In my earlier fix we were trying to allocate from the block group, but we weren't waiting for the progress because we were only waiting for the free space to be >= the amount of free space we wanted. My fix made it so we waited for forward progress to be made as well, so we would be sure to wait. This time however we did not have a block group that matched our size class, so what was happening was this find_free_extent for_each_block_group { ffe_ctl->cached == btrfs_block_group_cache_done(bg) if (!ffe_ctl->cached) ffe_ctl->have_caching_bg = true; if (size_class_doesn't_match()) goto loop; do_allocation() btrfs_wait_block_group_cache_progress(); loop: release_block_group(block_group); } if (loop == LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg) go search again; The size_class_doesn't_match() part was true, so we'd just skip this block group and never wait for caching, and then because we found a caching block group we'd just go back and do the loop again. We never sleep and thus never flush the plug and we have the same deadlock. Fix the logic for waiting on the block group caching to instead do it unconditionally when we goto loop. This takes the logic out of the allocation step, so now the loop looks more like this find_free_extent for_each_block_group { ffe_ctl->cached == btrfs_block_group_cache_done(bg) if (!ffe_ctl->cached) ffe_ctl->have_caching_bg = true; if (size_class_doesn't_match()) goto loop; do_allocation() btrfs_wait_block_group_cache_progress(); loop: if (loop > LOOP_CACHING_NOWAIT && !ffe_ctl->retry_uncached && !ffe_ctl->cached) { ffe_ctl->retry_uncached = true; btrfs_wait_block_group_cache_progress(); } release_block_group(block_group); } if (loop == LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg) go search again; This simplifies the logic a lot, and makes sure that if we're hitting uncached block groups we're always waiting on them at some point. I ran this through 100 iterations of generic/475, as this particular case was harder to hit than the previous one. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: handle errors properly in update_inline_extent_backref()Qu Wenruo
[PROBLEM] Inside function update_inline_extent_backref(), we have several BUG_ON()s along with some ASSERT()s which can be triggered by corrupted filesystem. [ANAYLYSE] Most of those BUG_ON()s and ASSERT()s are just a way of handling unexpected on-disk data. Although we have tree-checker to rule out obviously incorrect extent tree blocks, it's not enough for these ones. Thus we need proper error handling for them. [FIX] Thankfully all the callers of update_inline_extent_backref() would eventually handle the errror by aborting the current transaction. So this patch would do the proper error handling by: - Make update_inline_extent_backref() to return int The return value would be either 0 or -EUCLEAN. - Replace BUG_ON()s and ASSERT()s with proper error handling This includes: * Dump the bad extent tree leaf * Output an error message for the cause This would include the extent bytenr, num_bytes (if needed), the bad values and expected good values. * Return -EUCLEAN Note here we remove all the WARN_ON()s, as eventually the transaction would be aborted, thus a backtrace would be triggered anyway. - Better comments on why we expect refs == 1 and refs_to_mode == -1 for tree blocks Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: zoned: don't activate non-DATA BG on allocationNaohiro Aota
Now that a non-DATA block group is activated at write time, don't activate it on allocation time. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: move comments to btrfs_loop_type definitionJosef Bacik
Some of these loop types aren't described, and they should be with the definitions to make it easier to tell what each of them do. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: move btrfs_free_excluded_extents() into block-group.cFilipe Manana
The function btrfs_free_excluded_extents() is only used by block-group.c, so move it into block-group.c and make it static. Also removed unnecessary variables that are used only once. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21btrfs: open code trivial btrfs_add_excluded_extent()Filipe Manana
The code for btrfs_add_excluded_extent() is trivial, it's just a set_extent_bit() call. However it's defined in extent-tree.c but it is only used (twice) in block-group.c. So open code it in block-group.c, reducing the need to export a trivial function. Also since the only caller btrfs_add_excluded_extent() is prepared to deal with errors, stop ignoring errors from the set_extent_bit() call. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>