92 Commits

Author SHA1 Message Date
Kent Overstreet
97996ddfdb bcachefs: bch2_subvolume_get()
Factor out a little helper.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:13 -04:00
Kent Overstreet
ea0531f84e bcachefs: Fix check_inode_update_hardlinks()
We were incorrectly using bch2_inode_write(), which gets the snapshot ID
from the iterator, with a BTREE_ITER_ALL_SNAPSHOTS iterator -
fortunately caught by an assertion in the update path.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:13 -04:00
Kent Overstreet
42d237320e bcachefs: Snapshot creation, deletion
This is the final patch in the patch series implementing snapshots.
This patch implements two new ioctls that work like creation and
deletion of directories, but fancier.

 - BCH_IOCTL_SUBVOLUME_CREATE, for creating new subvolumes and snaphots
 - BCH_IOCTL_SUBVOLUME_DESTROY, for deleting subvolumes and snapshots

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:13 -04:00
Kent Overstreet
18443cb9f0 bcachefs: Update data move path for snapshots
The data move path operates on existing extents, and not within a
subvolume as the regular IO paths do. It needs to change because it may
cause existing extents to be split, and when splitting an existing
extent in an ancestor snapshot we need to make sure the new split has
the same visibility in child snapshots as the existing extent.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
ef1669ffc6 bcachefs: Update fsck for snapshots
This updates the fsck algorithms to handle snapshots - meaning there
will be multiple versions of the same key (extents, inodes, dirents,
xattrs) in different snapshots, and we have to carefully consider which
keys are visible in which snapshot.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
6fed42bb77 bcachefs: Plumb through subvolume id
To implement snapshots, we need every filesystem btree operation (every
btree operation without a subvolume) to start by looking up the
subvolume and getting the current snapshot ID, with
bch2_subvolume_get_snapshot() - then, that snapshot ID is used for doing
btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.

This patch adds those bch2_subvolume_get_snapshot() calls, and also
switches to passing around a subvol_inum instead of just an inode
number.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
81ed9ce367 bcachefs: Per subvolume lost+found
On existing filesystems, we have a single global lost+found. Introducing
subvolumes means we need to introduce per subvolume lost+found
directories, because inodes are added to lost+found by their inode
number, and inode numbers are now only unique within a subvolume.

This patch adds support to fsck for per subvolume lost+found.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
b9e1adf579 bcachefs: Add support for dirents that point to subvolumes
Dirents currently always point to inodes. Subvolumes add a new type of
dirent, with d_type DT_SUBVOL, that instead points to an entry in the
subvolumes btree, and the subvolume has a pointer to the root inode.

This patch adds bch2_dirent_read_target() to get the inode (and
potentially subvolume) a dirent points to, and changes existing code to
use that instead of reading from d_inum directly.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
14b393ee76 bcachefs: Subvolumes, snapshots
This patch adds subvolume.c - support for the subvolumes and snapshots
btrees and related data types and on disk data structures. The next
patches will start hooking up this new code to existing code.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
67e0dd8f0d bcachefs: btree_path
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>
2023-10-22 17:09:11 -04:00
Kent Overstreet
1a488e7306 bcachefs: Kill BTREE_INSERT_NOUNLOCK
With the recent transaction restart changes, it's no longer needed - all
transaction commits have BTREE_INSERT_NOUNLOCK semantics.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:10 -04:00
Kent Overstreet
3820054426 bcachefs: Don't squash return code in check_dirents()
We were squashing BCH_FSCK_ERRORS_NOT_FIXED.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:09 -04:00
Kent Overstreet
914f2786b8 bcachefs: Improvements to fsck check_dirents()
The fsck code handles transaction restarts in a very ad hoc way, and not
always correctly. This patch makes some improvements to check_dirents(),
but more work needs to be done to figure out how this kind of code
should be structured.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:08 -04:00
Kent Overstreet
8c3f6da9fc bcachefs: Improve iter->should_be_locked
Adding iter->should_be_locked introduced a regression where it ended up
not being set on the iterator passed to bch2_btree_update_start(), which
is definitely not what we want.

This patch requires it to be set when calling bch2_trans_update(), and
adds various fixups to make that happen.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:06 -04:00
Kent Overstreet
b89726ab86 bcachefs: Kill __btree_delete_at()
With trans->updates2 gone, we can now drop this helper and use
bch2_btree_delete_at() instead.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:06 -04:00
Kent Overstreet
bc3f8b25f3 bcachefs: Check for errors from bch2_trans_update()
Upcoming refactoring is going to change bch2_trans_update() to start
returning transaction restarts.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:05 -04:00
Kent Overstreet
82355e2882 bcachefs: Fix a memcpy call
Not supposed to pass a null ptr to memcpy (even if the size is 0).

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:03 -04:00
Kent Overstreet
909004d2f9 bcachefs: Make sure to use BTREE_ITER_PREFETCH in fsck
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:03 -04:00
Kent Overstreet
fc51b041b7 bcachefs: New check_nlinks algorithm for snapshots
With snapshots, using a radix tree for the table of link counts won't
work anymore because we also need to distinguish between inodes with
different snapshot IDs. Instead, this patch builds up a sorted array of
inodes that have hardlinks that we can binary search on - taking
advantage of the fact that with inode backpointers, the check_nlinks()
pass _only_ needs to concern itself with inodes that have hardlinks now.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:02 -04:00
Kent Overstreet
e3b4b48c17 bcachefs: Fix a null ptr deref
Fix a few memory safety issues, found by asan in userspace.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:02 -04:00
Kent Overstreet
58686a259e bcachefs: Lookup/create lost+found lazily
This is prep work for subvolumes - each subvolume will have its own
lost+found.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:01 -04:00
Kent Overstreet
f02810a1a4 bcachefs: Fix an unused var warning in userspace
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:01 -04:00
Kent Overstreet
f24fab9cba bcachefs: Fix some small memory leaks
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:01 -04:00
Kent Overstreet
ae8bbb9fac bcachefs: Simplify fsck remove_dirent()
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:01 -04:00
Kent Overstreet
d3ff7fec9c bcachefs: Improved check_directory_structure()
Now that we have inode backpointers, we can simplify checking directory
structure: instead of doing a DFS from the filesystem root and then
checking if we found everything, we can iterate over every inode and see
if we can go up until we get to the root.

This patch also has a number of fixes and simplifications for the inode
backpointer checks. Also, it turns out we don't actually need the
BCH_INODE_BACKPTR_UNTRUSTED flag.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:00 -04:00
Kent Overstreet
176cf4bf59 bcachefs: Fix fsck to not use bch2_link_trans()
bch2_link_trans() uses the btree key cache for inode updates, and fsck
isn't supposed to - also, it's not really what we want for reattaching
unreachable inodes anyways.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:00 -04:00
Kent Overstreet
b906aaddf2 bcachefs: Redo check_nlink fsck pass
Now that we have inode backpointers the check_nlink pass only is
concerned with files that have hardlinks, and can be simplified.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:00 -04:00
Kent Overstreet
8a85b20cd7 bcachefs: Inode backpointers are now required
This lets us simplify fsck quite a bit, which we need for making fsck
snapshot aware.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:59 -04:00
Kent Overstreet
7ac2c55e4d bcachefs: Simplify hash table checks
Very early on there was a period where we were accidentally generating
dirents with trailing garbage; we've since dropped support for
filesystems that old and the fsck code can be dropped.

Also, this patch switches to a simpler algorithm for checking hash
tables. It's less efficient on hash collision - but with 64 bit keys,
those are very rare.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:59 -04:00
Kent Overstreet
5c16add5ad bcachefs: Check inodes at start of fsck
This splits out checking inode nlinks from the rest of the inode checks
and moves most of the inode checks to the start of fsck, so that other
fsck passes can depend on it.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:59 -04:00
Kent Overstreet
3a14d58e7b bcachefs: Drop bch2_fsck_inode_nlink()
We've had BCH_FEATURE_atomic_nlink for quite some time, we can drop this
now.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:59 -04:00
Kent Overstreet
b6d4f474e4 bcachefs: Move some dirent checks to bch2_dirent_invalid()
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:59 -04:00
Kent Overstreet
ab2a29ccff bcachefs: Inode backpointers
This patch adds two new inode fields, bi_dir and bi_dir_offset, that
point back to the inode's dirent.

Since we're only adding fields for a single backpointer, files that have
been hardlinked won't necessarily have valid backpointers: we also add a
new inode flag, BCH_INODE_BACKPTR_UNTRUSTED, that's set if an inode has
ever had multiple links to it. That's ok, because we only really need
this functionality for directories, which can never have multiple
hardlinks - when we add subvolumes, we'll need a way to enemurate and
print subvolumes, and this will let us reconstruct a path to a subvolume
root given a subvolume root inode.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:58 -04:00
Kent Overstreet
e751c01a8e bcachefs: Start using bpos.snapshot field
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>
2023-10-22 17:08:57 -04:00
Kent Overstreet
e0ba3b6429 bcachefs: Replace bch2_btree_iter_next() calls with bch2_btree_iter_advance
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>
2023-10-22 17:08:56 -04:00
Kent Overstreet
50dc0f692a bcachefs: Require all btree iterators to be freed
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>
2023-10-22 17:08:56 -04:00
Kent Overstreet
abcecb49f5 bcachefs: Fsck code refactoring
Change fsck code to always put btree iterators - also, make some flow
control improvements to deal with lock restarts better, and refactor
check_extents() to not walk extents twice for counting/checking
i_sectors.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:56 -04:00
Kent Overstreet
c7bb769c81 bcachefs: __bch2_trans_get_iter() refactoring, BTREE_ITER_NOT_EXTENTS
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
41f8b09edc bcachefs: Rename BTREE_ID enums for consistency with other enums
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
79f88eba01 bcachefs: Rename KEY_TYPE_whiteout -> KEY_TYPE_hash_whiteout
Snapshots are going to need a different whiteout key type. Also, switch
to using BCH_BKEY_TYPES() to define the bkey value accessors.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
fe38b72086 bcachefs: Don't use inode btree key cache in fsck code
We had a cache coherency bug with the btree key cache in the fsck code -
this fixes fsck to be consistent about not using it.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:53 -04:00
Kent Overstreet
2bb748a695 bcachefs: Fsck fixes
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:53 -04:00
Kent Overstreet
eaf798317a bcachefs: Fix for hash_redo_key() in fsck
It's possible we're calling hash_redo_key() because of a duplicate key -
easiest fix for that is to just not use BCH_HASH_SET_MUST_CREATE.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:53 -04:00
Kent Overstreet
07a1006ae8 bcachefs: Reduce/kill BKEY_PADDED use
With various newer key types - stripe keys, inline data extents - the
old approach of calculating the maximum size of the value is becoming
more and more error prone. Better to switch to bkey_on_stack, which can
dynamically allocate if necessary to handle any size bkey.

In particular we also want to get rid of BKEY_EXTENT_VAL_U64s_MAX.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:50 -04:00
Kent Overstreet
3eb26d0157 bcachefs: bch2_trans_get_iter() no longer returns errors
Since we now always preallocate the maximum number of iterators when we
initialize a btree transaction, getting an iterator never fails - we can
delete a fair amount of error path code.

This patch also simplifies the iterator allocation code a bit.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:48 -04:00
Kent Overstreet
34c1cd6a59 bcachefs: Fix for fsck spuriously finding duplicate extents
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:48 -04:00
Kent Overstreet
6584e84a97 bcachefs: Don't use bkey cache for inode update in fsck
fsck doesn't know about the btree key cache, and non-cached iterators
aren't cache coherent (yet?)

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:48 -04:00
Kent Overstreet
fe4584765d bcachefs: use a radix tree for inum bitmap in fsck
The change to use the cpu nr for the high bits of new inode numbers
means that inode numbers are very space - we see -ENOMEM during fsck
without this.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:46 -04:00
Kent Overstreet
a3e7226268 bcachefs: New varints
Previous varint implementation used by the inode code was not nearly as
fast as it could have been; partly because it was attempting to encode
integers up to 96 bits (for timestamps) but this meant that encoding and
decoding the length required a table lookup.

Instead, we'll just encode timestamps greater than 64 bits as two
separate varints; this will make decoding/encoding of inodes
significantly faster overall.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:46 -04:00
Kent Overstreet
a672fb8f5d bcachefs: Make sure to go rw if lazy in fsck
The paths where we delete or truncate inodes don't pass commit flags for
BTREE_INSERT_LAZY_RW, so just go rw if necessary in the fsck code.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:44 -04:00