Quota support was disabled when snapshots were released, because of some
tricky interactions with snpashots. We're sidestepping that for now -
we're simply disabling quota accounting on snapshot subvolumes.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This fixes another i_sectors accounting bug - we need to differentiate
between dirty writes that overwrite a reservation and dirty writes to
unallocated space - dirty writes to unallocated space increase
i_sectors, dirty writes over a reservation do not.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

When bch2_truncate_page() discards dirty sectors in the page cache, we
need to account for that - we don't need to account for allocated
sectors because that'll be done by the bch2_fpunch() call when it
updates the btree.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

We weren't checking for errors before calling i_sectors_acct()
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

We were setting BCH_FS_ERROR on startup if the superblock was marked as
containing errors, which is not what we wanted - BCH_FS_ERROR indicates
whether errors have been found, so that after a successful fsck we're
able to clear the error bit in the superblock.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This adds repair code to drop very stale pointers.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

- bch2_journal_halt() was unconditionally overwriting j->err_seq, the
  sequence number that we failed to write
- journal_write_done was updating seq_ondisk and flushed_seq_ondisk even
  for writes that errored, which broke the way bch2_journal_flush_seq_async()
  locklessly checked for completions.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

Currently, btree triggers are run in natural key order, which presents a
problem for fallocate in INSERT_RANGE mode: since we're moving existing
extents to higher offsets, the trigger for deleting the old extent runs
before the trigger that adds the new extent, potentially leading to
indirect extents being deleted that shouldn't be when the delete causes
the refcount to hit 0.

This changes the order we run triggers so that for a givin btree, we run
all insert triggers before overwrite triggers, nicely sidestepping this
issue.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

The filesystem initialization path first marks superblock and journal
buckets non transactionally, since the btree isn't functional yet. That
path was updating the per-journal-buf percpu counters via
bch2_dev_usage_update(), and updating the wrong set of counters so those
updates didn't get written out until journal entry 4.

The relevant code is going to get significantly rewritten in the future
as we transition away from the in memory bucket array, so this just
hacks around it for now.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

Change log messages in userspace to be closer to what they are in kernel
space, and include the device name - it's also useful in userspace.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

When support for snapshots was merged, export operations weren't
updated yet. This patch adds new filehandle types for bcachefs that
include the subvolume ID and updates export operations for subvolumes -
and also .get_parent, support for which was added just prior to
snapshots.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This consolidates duplicated code in journal replay - it's only a few
flags that are different for replaying alloc keys.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

When unpacking v1 inodes, we were failing to initialize the journal_seq
field, leading to a BUG_ON() when fsync tries to flush a garbage journal
sequence number.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

It's definitely indicative of a bug if we request to flush a journal
sequence number that hasn't happened yet, but it's more useful if we
warn and print out the relevant sequence numbers instead of just dying.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

.to_text methods generally ought to print all the value fields.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This patch converts more enums in the on disk format to our standard
x-macro-with-strings deal - to enable better pretty-printing.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

In bcachefs, inodes and dentries are also cached - more compactly - by
the btree node cache, they don't require seeks to recreate.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

bch2_dirent_lookup had an error path where we'd exit a btree_iter that
hadn't been properly initialized.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

When attempting to free btree nodes, we might not be able to free all
the nodes that were requested. But the code was looping until it had
freed _all_ the nodes requested, when it should have only been
attempting to free nr nodes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

If at all possible we'd prefer to not fail page writeback unless the
filesystem has been shutdown; allowing errors in page writeback means
things we'd like to assert about i_size consistency between the VFS and
the btree go out the window.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This fixes a bug where i_size may become inconsistent between the VFS
cache and the btree, when the filesystem is nearly full.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

- fpunch wasn't always correctly updating i_size - when we drop buffered
  writes that were extending a file, we become responsible for writing
  i_size.

- fzero was sometimes zeroing out more data that it should have -
  block_start and block_end were being rounded in the wrong directions
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This cleans up the error hanlding and flow control a bit.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This adds a new assertion to be used by bch2_inode_update_after_write(),
which updates the VFS inode based on the update to the btree inode we
just did - we require that the btree inode still be locked when we do
that update.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

 - We should only be clearing should_be_locked in btree_path_set_pos() -
   it's the responsiblity of the btree_path code, not the btree_iter
   code.

 - bch2_path_put() needs to pay attention to path->should_be_locked, to
   ensure we don't drop locks we're supposed to be keeping.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

It used to be that error reporting in the startup path was done by
returning strings describing the error, but that turned out to be a
rather silly idea - if there's something we can describe about the
error, just print it right away.

This converts a good chunk of code to returning error codes, as is more
typical style.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

bch2_fs_encryption_init() correctly passes back -ENOKEY from request_key()
when no unlock key is found, or -EINVAL if superblock decryption fails
because of an invalid key. However, these get absorbed into a generic NULL
return from bch2_fs_alloc() and later returned to user space as -ENOMEM,
leading to a misleading error from mount(1):

  mount(2) system call failed: Out of memory.

Return explicit error pointers out of bch2_fs_alloc() and handle them in
both callers, so the user instead sees

  mount(2) system call failed: Required key not available.

when attempting to mount a filesystem which is still locked.
Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

Now that we're recording in each inode the journal sequence number of
the most recent update, fsync becomes a lot simpler and we can delete
all the plumbing for ei_journal_seq.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

We're getting rid of code that uses the in memory bucket array - and we
now have better mechanisms for viewing most of what the bucket quantiles
code gave us (especially internal fragmentation).
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This was used for recording which inodes have been modified by in flight
journal writes, but was broken and has been superceded.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

Add fields to inode & alloc keys that record the journal sequence number
when they were most recently modified.

For alloc keys, this is needed to know what journal sequence number we
have to flush before the bucket can be reused. Currently this is tracked
in memory, but we'll be getting rid of the in memory bucket array.

For inodes, this is needed for fsync when the inode has been evicted
from the vfs cache. Currently we use a bloom filter per outstanding
journal buf - but that mechanism has been broken since we added the
ability to not issue a flush/fua for every journal write.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

This is going to be a performance regression until we get the btree key
cache re-enabled - but it's needed for fixing fsync. Upcoming patches
will record the journal_seq an inode was updated at in the inode itself.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We're going to have btree updates that don't need to be journalled; add
a flag for that.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

__lookup_inode() doesn't work for what __remove_dirent() wants - it just
wants the first inode at a given inode number, they all have the same
hash info.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

We were starting at the wrong btree position, and thus not actually
checking any inodes - oops.

Also, make check_key_has_snapshot() a mustfix fsck error, since later
fsck code assumes that all keys have valid snapshot IDs.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

It's helpful to know what the superblock write is for.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

On failure to get a write lock (because we had a conflicting read lock),
we need to make sure to upgrade the read lock to an intent lock - or we
could end up spinning.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

The bch2_btree_path_upgrade() call was failing and tripping an assert -
path->level + 1 is in this case not necessarily exactly what we want,
fix it by upgrading exactly the locks we want.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>