aboutsummaryrefslogtreecommitdiff
path: root/fs/bcachefs/debug.c
AgeCommit message (Collapse)AuthorFilesLines
2023-10-22bcachefs: GFP_NOIO -> GFP_NOFSKent Overstreet1-2/+2
GFP_NOIO dates from the bcache days, when we operated under the block layer. Now, GFP_NOFS is more appropriate, so switch all GFP_NOIO uses to GFP_NOFS. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: bch2_btree_node_ondisk_to_text()Kent Overstreet1-0/+119
Pulling out a helper from cmd_list.c, as the rest is being rewritten in Rust but we're not ready to rewrite lower-level btree code in Rust. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Drop some anonymous structs, unionsKent Overstreet1-1/+1
Rust bindgen doesn't cope well with anonymous structs and unions. This patch drops the fancy anonymous structs & unions in bkey_i that let us use the same helpers for bkey_i and bkey_packed; since bkey_packed is an internal type that's never exposed to outside code, it's only a minor inconvenienc. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: New backtrace utility codeKent Overstreet1-1/+1
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: debug: Fix some locking bugsKent Overstreet1-2/+2
This fixes a few error paths in debug code that lead to locks failing to be dropped. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Plumb saw_error through to btree_err()Kent Overstreet1-2/+2
The btree node read path has the ability to kick off an asynchronous btree node rewrite if we saw and corrected an error. Previously this was only used for errors that caused one of the replicas to be unusable - this patch plumbs it through to all error paths, so that normal fsck errors can be corrected. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: New bpos_cmp(), bkey_cmp() replacementsKent Overstreet1-3/+3
This patch introduces - bpos_eq() - bpos_lt() - bpos_le() - bpos_gt() - bpos_ge() and equivalent replacements for bkey_cmp(). Looking at the generated assembly these could probably be improved further, but we already see a significant code size improvement with this patch. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Assorted checkpatch fixesKent Overstreet1-1/+1
checkpatch.pl gives lots of warnings that we don't want - suggested ignore list: ASSIGN_IN_IF UNSPECIFIED_INT - bcachefs coding style prefers single token type names NEW_TYPEDEFS - typedefs are occasionally good FUNCTION_ARGUMENTS - we prefer to look at functions in .c files (hopefully with docbook documentation), not .h file prototypes MULTISTATEMENT_MACRO_USE_DO_WHILE - we have _many_ x-macros and other macros where we can't do this Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Optimize bch2_trans_init()Kent Overstreet1-3/+3
Now we store the transaction's fn idx in a local variable, instead of redoing the lookup every time we call bch2_trans_init(). Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Print cycle on unrecoverable deadlockKent Overstreet1-21/+1
Some lock operations can't fail; a cycle of nofail locks is impossible to recover from. So we want to get rid of these nofail locking operations, but as this is tricky it'll be done incrementally. If such a cycle happens, this patch prints out which codepaths are involved so we know what to work on next. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Improve btree_deadlock debugfs outputKent Overstreet1-5/+12
This changes bch2_check_for_deadlock() to print the longest chains it finds - when we have a deadlock because the cycle detector isn't finding something, this will let us see what it's missing. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Print deadlock cycle in debugfsKent Overstreet1-0/+43
In the event that we're not finished debugging the cycle detector, this adds a new file to debugfs that shows what the cycle detector finds, if anything. By comparing this with btree_transactions, which shows held locks for every btree_transaction, we'll be able to determine if it's the cycle detector that's buggy or something else. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Deadlock cycle detectorKent Overstreet1-3/+3
We've outgrown our own deadlock avoidance strategy. The btree iterator API provides an interface where the user doesn't need to concern themselves with lock ordering - different btree iterators can be traversed in any order. Without special care, this will lead to deadlocks. Our previous strategy was to define a lock ordering internally, and whenever we attempt to take a lock and trylock() fails, we'd check if the current btree transaction is holding any locks that cause a lock ordering violation. If so, we'd issue a transaction restart, and then bch2_trans_begin() would re-traverse all previously used iterators, but in the correct order. That approach had some issues, though. - Sometimes we'd issue transaction restarts unnecessarily, when no deadlock would have actually occured. Lock ordering restarts have become our primary cause of transaction restarts, on some workloads totally 20% of actual transaction commits. - To avoid deadlock or livelock, we'd often have to take intent locks when we only wanted a read lock: with the lock ordering approach, it is actually illegal to hold _any_ read lock while blocking on an intent lock, and this has been causing us unnecessary lock contention. - It was getting fragile - the various lock ordering rules are not trivial, and we'd been seeing occasional livelock issues related to this machinery. So, since bcachefs is already a relational database masquerading as a filesystem, we're stealing the next traditional database technique and switching to a cycle detector for avoiding deadlocks. When we block taking a btree lock, after adding ourself to the waitlist but before sleeping, we do a DFS of btree transactions waiting on other btree transactions, starting with the current transaction and walking our held locks, and transactions blocking on our held locks. If we find a cycle, we emit a transaction restart. Occasionally (e.g. the btree split path) we can not allow the lock() operation to fail, so if necessary we'll tell another transaction that it has to fail. Result: trans_restart_would_deadlock events are reduced by a factor of 10 to 100, and we'll be able to delete a whole bunch of grotty, fragile code. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: Track maximum transaction memoryKent Overstreet1-0/+3
This patch - tracks maximum bch2_trans_kmalloc() memory used in btree_transaction_stats - makes it available in debugfs - switches bch2_trans_init() to using that for the amount of memory to preallocate, instead of the parameter passed in This drastically reduces transaction restarts, and means we no longer need to track this in the source code. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Debugfs cleanupKent Overstreet1-64/+51
This improves flush_buf() so that it always returns nonzero when we're done reading and ready to return to userspace, and so that it returns the value we want to return to userspace (number of bytes read, if there wasn't an error). In the future we'll be better abstracting this mechanism and pulling it out of bcachefs, and using it to replace seq_file. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: Print last line in debugfs/btree_transaction_statsKent Overstreet1-2/+5
We need to turn the flush_buf() thing into a proper API, to replace seq_file. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: Track the maximum btree_paths ever allocated by each transactionKent Overstreet1-5/+25
We need a way to check if the machinery for handling btree_paths with in a transaction is behaving reasonably, as it often has not been - we've had bugs with transaction path overflows caused by duplicate paths and plenty of other things. This patch tracks, per transaction fn, the most btree paths ever allocated by that transaction and makes it available in debugfs. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Rename lock_held_stats -> btree_transaction_statsKent Overstreet1-7/+10
Going to be adding more things to this in the next patch. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Convert debugfs code to for_each_btree_key2()Kent Overstreet1-48/+31
This fixes a bug where we were leaking a transaction restart error to userspace. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: added lock held time statsDaniel Hill1-0/+74
We now record the length of time btree locks are held and expose this in debugfs. Enabled via CONFIG_BCACHEFS_LOCK_TIME_STATS. Signed-off-by: Daniel Hill <daniel@gluo.nz> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Improve an error messageKent Overstreet1-0/+77
When inserting a key type that's not valid for a given btree, we should print out which btree we were inserting into. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Printbuf reworkKent Overstreet1-43/+44
This converts bcachefs to the modern printbuf interface/implementation, synced with the version to be submitted upstream. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Fix usage of six lock's percpu modeKent Overstreet1-0/+5
Six locks have a percpu mode, which we use for interior btree nodes, as well as btree key cache keys for the subvolumes btree. We've been switching locks back and forth between percpu and non percpu mode as needed, but it turns out this is racy - when we're reusing an existing node, other threads could be attempting to lock it while we're switching it between modes. This patch fixes this by never switching 'struct btree' between the two modes, and instead segragating them between two different freed lists. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Start moving debug info from sysfs to debugfsKent Overstreet1-13/+163
In sysfs, files can only output at most PAGE_SIZE. This is a problem for debug info that needs to list an arbitrary number of times, and because of this limit some of our debug info has been terser and harder to read than we'd like. This patch moves info about journal pins and cached btree nodes to debugfs, and greatly expands and improves the output we return. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: Heap allocate printbufsKent Overstreet1-22/+20
This patch changes printbufs dynamically allocate and reallocate a buffer as needed. Stack usage has become a bit of a problem, and a major cause of that has been static size string buffers on the stack. The most involved part of this refactoring is that printbufs must now be exited with printbuf_exit(). Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Fix debugfs -bfloat-failedKent Overstreet1-1/+3
It wasn't updated for snapshots - it's iterating across keys in all snapshots, so needs to be specifying BTREE_ITER_ALL_SNAPSHOTS. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: Add missing bch2_trans_iter_exit() callKent Overstreet1-0/+2
This fixes a bug where the filesystem goes read only when reading from debugfs. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: for_each_btree_node() now returns errors directlyKent Overstreet1-1/+1
This changes for_each_btree_node() to work like for_each_btree_key(), and to that end bch2_btree_iter_peek_node() and next_node() also return error ptrs. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: btree_pathKent Overstreet1-16/+16
This splits btree_iter into two components: btree_iter is now the externally visible componont, and it points to a btree_path which is now reference counted. This means we no longer have to clone iterators up front if they might be mutated - btree_path can be shared by multiple iterators, and cloned if an iterator would mutate a shared btree_path. This will help us use iterators more efficiently, as well as slimming down the main long lived state in btree_trans, and significantly cleans up the logic for iterator lifetimes. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Really don't hold btree locks while btree IOs are in flightKent Overstreet1-2/+2
This is something we've attempted to stick to for quite some time, as it helps guarantee filesystem latency - but there's a few remaining paths that this patch fixes. This is also necessary for an upcoming patch to update btree pointers after every btree write - since the btree write completion path will now be doing btree operations. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Split out SPOS_MAXKent Overstreet1-2/+2
Internal btree code really wants a POS_MAX with all fields ~0; external code more likely wants the snapshot field to be 0, because when we're passing it to bch2_trans_get_iter() it's used for the snapshot we're operating in, which should be 0 for most btrees that don't use snapshots. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22bcachefs: Update bch2_btree_verify()Kent Overstreet1-41/+79
bch2_btree_verify() verifies that the btree node on disk matches what we have in memory. This patch changes it to verify every replica, and also fixes it for interior btree nodes - there's a mem_ptr field which is used as a scratch space and needs to be zeroed out for comparing with what's on disk. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Eliminate more PAGE_SIZE usesKent Overstreet1-2/+2
In userspace, we don't really have a well defined PAGE_SIZE and shouln't be relying on it. This is some more incremental work to remove references to it. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Start using bpos.snapshot fieldKent Overstreet1-2/+4
This patch starts treating the bpos.snapshot field like part of the key in the btree code: * bpos_successor() and bpos_predecessor() now include the snapshot field * Keys in btrees that will be using snapshots (extents, inodes, dirents and xattrs) now always have their snapshot field set to U32_MAX The btree iterator code gets a new flag, BTREE_ITER_ALL_SNAPSHOTS, that determines whether we're iterating over keys in all snapshots or not - internally, this controlls whether bkey_(successor|predecessor) increment/decrement the snapshot field, or only the higher bits of the key. We add a new member to struct btree_iter, iter->snapshot: when BTREE_ITER_ALL_SNAPSHOTS is not set, iter->pos.snapshot should always equal iter->snapshot, which will be 0 for btrees that don't use snapshots, and alsways U32_MAX for btrees that will use snapshots (until we enable snapshot creation). This patch also introduces a new metadata version number, and compat code for reading from/writing to older versions - this isn't a forced upgrade (yet). Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Split out bpos_cmp() and bkey_cmp()Kent Overstreet1-2/+2
With snapshots, we're going to need to differentiate between comparisons that should and shouldn't include the snapshot field. bpos_cmp is now the comparison function that does include the snapshot field, used by core btree code. Upper level filesystem code generally does _not_ want to compare against the snapshot field - that code wants keys to compare as equal even when one of them is in an ancestor snapshot. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Replace bch2_btree_iter_next() calls with bch2_btree_iter_advanceKent Overstreet1-1/+1
The way btree iterators work internally has been changing, particularly with the iter->real_pos changes, and bch2_btree_iter_next() is no longer hyper optimized - it's just advance followed by peek, so it's more efficient to just call advance where we're not using the return value of bch2_btree_iter_next(). Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Require all btree iterators to be freedKent Overstreet1-0/+4
We keep running into occasional bugs with btree transaction iterators overflowing - this will make those bugs more visible. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Include device in btree IO error messagesKent Overstreet1-1/+1
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Drop sysfs interface to debug parametersKent Overstreet1-1/+1
It's not used much anymore, the module paramter interface is better. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Change bch2_dump_bset() to also print key valuesKent Overstreet1-3/+3
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Kill direct access to bi_io_vecKent Overstreet1-2/+1
Switch to always using bio_add_page(), which merges contiguous pages now that we have multipage bvecs. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: More work to avoid transaction restartsKent Overstreet1-3/+3
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: btree_bkey_cached_commonKent Overstreet1-2/+2
This is prep work for the btree key cache: btree iterators will point to either struct btree, or a new struct bkey_cached. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: trans_for_each_iter()Kent Overstreet1-2/+2
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Only get btree iters from btree transactionsKent Overstreet1-16/+25
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Make bkey types globally uniqueKent Overstreet1-3/+3
this lets us get rid of a lot of extra switch statements - in a lot of places we dispatch on the btree node type, and then the key type, so this is a nice cleanup across a lot of code. Also improve the on disk format versioning stuff. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: revamp to_text methodsKent Overstreet1-9/+8
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: extent_ptr_decodedKent Overstreet1-1/+1
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22bcachefs: Initial commitKent Overstreet1-0/+425
Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write filesystem with every feature you could possibly want. Website: https://bcachefs.org Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Powered by cgit, Gruvboxed by Blaster4385.