This adds a small (64 bit) per-device bitmap that tracks ranges that
have btree nodes, for accelerating btree node scan if it is ever needed.
- New helpers, bch2_dev_btree_bitmap_marked() and
bch2_dev_bitmap_mark(), for checking and updating the bitmap
- Interior btree update path updates the bitmaps when required
- The check_allocations pass has a new fsck_err check,
btree_bitmap_not_marked
- New on disk format version, mi_btree_mitmap, which indicates the new
bitmap is present
- Upgrade table lists the required recovery pass and expected fsck error
- Btree node scan uses the bitmap to skip ranges if we're on the new
version
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is needed for building Rust bindings on big endian architectures
like s390x. Currently this is only done in userspace, but it might
happen in-kernel in the future. When creating a Rust binding for struct
bkey, the "packed" attribute is needed to get a type with the correct
member offsets in the big endian case. However, rustc does not allow
types to have both a "packed" and "align" attribute. Thus, in order to
get a Rust type compatible with the C type, we must omit the "aligned"
attribute in C.
This does not affect the struct's size or member offsets, only its
toplevel alignment, which should be an acceptable impact.
The little endian version can have the "align" attribute because the
"packed" attr is redundant, and rust-bindgen will omit the "packed" attr
when an "align" attr is present and it can do so without changing a
type's layout
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a btree to record a parent -> child subvolume relationships,
according to the filesystem heirarchy.
The subvolume_children btree is a bitset btree: if a bit is set at pos
p, that means p.offset is a child of subvolume p.inode.
This will be used for efficiently listing subvolumes, as well as
recursive deletion.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This gives us a way to record the date and time every journal entry was
written - useful for debugging.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a field to bch_snapshot for creation time; this will be important
when we start exposing the snapshot tree to userspace.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add new fields for split brain detection:
- bch_member->seq, which tracks the sequence number of the last superblock
write that happened to each member device
- bch_sb->write_time, which tracks the time of the last superblock write,
to allow detection of when two members have diverged but had the same
number of superblock writes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previosuly, the transaction commit path would have to add keys to the
btree write buffer as a separate operation, requiring additional global
synchronization.
This patch introduces a new journal entry type, which indicates that the
keys need to be copied into the btree write buffer prior to being
written out. We switch the journal entry type back to
JSET_ENTRY_btree_keys prior to write, so this is not an on disk format
change.
Flushing the btree write buffer may require pulling keys out of journal
entries yet to be written, and quiescing outstanding journal
reservations; we previously added journal->buf_lock for synchronization
with the journal write path.
We also can't put strict bounds on the number of keys in the journal
destined for the write buffer, which means we might overflow the size of
the preallocated buffer and have to reallocate - this introduces a
potentially fatal memory allocation failure. This is something we'll
have to watch for, if it becomes an issue in practice we can do
additional mitigation.
The transaction commit path no longer has to explicitly check if the
write buffer is full and wait on flushing; this is another performance
optimization. Instead, when the btree write buffer is close to full we
change the journal watermark, so that only reservations for journal
reclaim are allowed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- add a tracepoint for write_buffer_flush_sync; this is expensive
- fix the write_buffer_flush_slowpath tracepoint
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This counter is redundant; it's simply the sum of BCH_DATA_stripe and
BCH_DATA_parity buckets.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new superblock section that contains a list of
{ minor version, recovery passes, errors_to_fix }
that is - a list of recovery passes that must be run when downgrading
past a given version, and a list of errors to silently fix.
The upcoming disk accounting rewrite is not going to be fully
compatible: we're going to have to regenerate accounting both when
upgrading to the new version, and also from downgrading from the new
version, since the new method of doing disk space accounting is a
completely different architecture based on deltas, and synchronizing
them for every jounal entry write to maintain compatibility is going to
be too expensive and impractical.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add two new superblock fields. Since the main section of the superblock
is now fully, we have to add a new variable length section for them -
bch_sb_field_ext.
- recovery_passes_requried: recovery passes that must be run on the
next mount
- errors_silent: errors that will be silently fixed
These are to improve upgrading and dwongrading: these fields won't be
cleared until after recovery successfully completes, so there won't be
any issues with crashing partway through an upgrade or a downgrade.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Renamed from trace_move_extent_alloc_mem_fail, because there are other
reasons we colud fail (disk space allocation failure).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bkey embeds a bpos that is misaligned on big endian; this is so that
bch2_bkey_swab() works correctly without having to differentiate between
packed and non-packed keys (a debatable design decision).
This means it can't have the __aligned() tag on big endian.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
rebalance_work entries may refer to entries in the extents btree, which
is a snapshots btree, or they may also refer to entries in the reflink
btree, which is not.
Hence rebalance_work keys may use the snapshot field but it's not
required to be nonzero - add a new btree flag to reflect this.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
gcc 10 seems to complain about array bounds in situations where gcc 11
does not - curious.
This unfortunately requires adding some casts for now; we may
investigate getting rid of our __u64 _data[] VLA in a future patch so
that our start[0] members can be VLAs.
Reported-by: John Stoffel <john@stoffel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new superblock section to keep counts of errors seen since
filesystem creation: we'll be addingcounters for every distinct fsck
error.
The new superblock section has entries of the for [ id, count,
time_of_last_error ]; this is intended to let us see what errors are
occuring - and getting fixed - via show-super output.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We now track IO errors per device since filesystem creation.
IO error counts can be viewed in sysfs, or with the 'bcachefs
show-super' command.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new btree, rebalance_work, to eliminate scanning required
for finding extents that need work done on them in the background - i.e.
for the background_target and background_compression options.
rebalance_work is a bitset btree, where a KEY_TYPE_set corresponds to an
extent in the extents or reflink btree at the same pos.
A new extent field is added, bch_extent_rebalance, which indicates that
this extent has work that needs to be done in the background - and which
options to use. This allows per-inode options to be propagated to
indirect extents - at least in some circumstances. In this patch,
changing IO options on a file will not propagate the new options to
indirect extents pointed to by that file.
Updating (setting/clearing) the rebalance_work btree is done by the
extent trigger, which looks at the bch_extent_rebalance field.
Scanning is still requrired after changing IO path options - either just
for a given inode, or for the whole filesystem. We indicate that
scanning is required by adding a KEY_TYPE_cookie key to the
rebalance_work btree: the cookie counter is so that we can detect that
scanning is still required when an option has been flipped mid-way
through an existing scan.
Future possible work:
- Propagate options to indirect extents when being changed
- Add other IO path options - nr_replicas, ec, to rebalance_work so
they can be applied in the background when they change
- Add a counter, for bcachefs fs usage output, showing the pending
amount of rebalance work: we'll probably want to do this after the
disk space accounting rewrite (moving it to a new btree)
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
members_v2 has dynamically resizable entries so that we can extend
bch_member. The members can no longer be accessed with simple array
indexing Instead members_v2_get is used to find a member's exact
location within the array and returns a copy of that member.
Alternatively member_v2_get_mut retrieves a mutable point to a member.
Signed-off-by: Hunter Shaffer <huntershaffer182456@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that we have the logged operations btree, we can make
finsert/fcollapse atomic w.r.t. unclean shutdown as well.
This adds bch_logged_op_finsert to represent the state of an finsert or
fcollapse, which is a bit more complicated than truncate since we need
to track our position in the "shift extents" operation.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, we guaranteed atomicity of truncate after unclean shutdown
with the BCH_INODE_I_SIZE_DIRTY flag - which required a full scan of the
inodes btree.
Recently the deleted inodes btree was added so that we no longer have to
scan for deleted inodes, but truncate was unfinished and that change
left it broken.
This patch uses the new logged operations btree to fix truncate
atomicity; we now log an operation that can be replayed at the start of
a truncate.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new btree for long running logged operations - i.e. for logging
operations that we can't do within a single btree transaction, so that
they can be resumed if we crash.
Keys in the logged operations btree will represent operations in
progress, with the state of the operation stored in the value.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It's no longer legal to use a zero size array as a flexible array
member - this causes UBSAN to complain.
This patch switches our zero size arrays to normal flexible array
members when possible, and inserts casts in other places (e.g. where we
use the zero size array as a marker partway through an array).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
After deleteing snapshots, we may be left with a snapshot tree where
some nodes only have one child, and we have a linear chain.
Interior snapshot nodes are never used directly (i.e. they never have
subvolumes that point to them), they are only referered to by child
snapshot nodes - hence, they are redundant.
The existing code talks about redundant snapshot nodes as forming and
equivalence class; i.e. nodes for which snapshot_t->equiv is equal. In a
given equivalence class, we only ever need a single key at a given
position - i.e. multiple versions with different snapshot fields are
redundant.
The existing snapshot cleanup code deletes these redundant keys, but not
redundant nodes. It turns out this is buggy, because we assume that
after snapshot deletion finishes we should only have a single key per
equivalence class, but the btree update path doesn't preserve this -
overwriting keys in old snapshots doesn't check for the equivalence
class being equal, and thus we can end up with duplicate keys in the
same equivalence class and fsck complaining about snapshot deletion not
having run correctly.
The equivalence class notion has been leaking out of the core snapshots
code and into too much other code, i.e. fsck, so this patch takes a
different approach: snapshot deletion now moves keys to the node in an
equivalence class being kept (the leafiest node) and then deletes the
redundant nodes in the equivalance class.
Some work has to be done to correctly delete interior snapshot nodes;
snapshot node depth and skiplist fields for descendent nodes have to be
fixed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet