This changes the on disk format for dirents that point to subvols so
that they also record the subvolid of the parent subvol, so that we can
filter them out in other subvolumes.
This also updates the dirent code to do that filtering, and in
particular tweaks the rename code - we need to ensure that there's only
ever one dirent (counting multiplicities in different snapshots) that
point to a subvolume.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
check_path() wasn't checking the snapshot ID when checking for directory
structure loops - so, snapshots would cause us to detect a loop that
wasn't actually a loop.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
When a reflink pointer points to only part of an indirect extent, and
then that indirect extent is fragmented (e.g. by copygc), if the reflink
pointer only points to one of the fragments we leak a reference.
Fix this by storing front/back pad values in reflink pointers - when
inserting reflink pointesr, we initialize them to cover the full range
of the indirect extents we reference.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
We had a bug where reflink_p pointers weren't being initialized to 0,
and when we started using the second word, things broke badly.
This patch revs the on disk format version and adds cleanup code to zero
out the second word of reflink_p pointers before we start using it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Now that peek_node()/next_node() are converted to return errors
directly, we don't need bch2_trans_exit() to return errors - it's
cleaner this way and wasn't used much anymore.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Checking of directory structure across subvolumes was broken - we need
to look up the snapshot ID of the parent subvolume when crossing subvol
boundaries.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Upcoming refactoring is going to change bch2_trans_update() to start
returning transaction restarts.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
