bkey_fsck_err() was added as an interface that looks like fsck_err(),
but previously all it did was ensure that the appropriate error counter
was incremented in the superblock.

This is a cleanup and bugfix patch that converts it to a wrapper around
fsck_err(). This is needed to fix an issue with the upgrade path to
disk_accounting_v3, where the "silent fix" error list now includes
bkey_fsck errors; fsck_err() handles this in a unified way, and since we
need to change printing of bkey fsck errors from the caller to the inner
bkey_fsck_err() calls, this ends up being a pretty big change.

Als,, rename .invalid() methods to .validate(), for clarity, while we're
changing the function signature anyways (to drop the printbuf argument).

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We can't hold locks while waiting for user input, that's a deadlock.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We now read the line from the buffer atomically, which means we have to
allow the buffer to grow past STDIO_REDIRECT_BUFSIZE if we're waiting
for a full line - this behaviour is necessary for
stdio_redirect_readline_timeout() in the next patch.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fsck_err() now optionally takes a btree_trans; if the current thread has
one, it is required that it be passed.

The next patch will use this to unlock when waiting for user input.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

i.e. the start of automatic self healing:

If errors=continue or fix_safe, we now automatically fix simple errors
without user intervention.

New error action option: fix_safe

This replaces the existing errors=ro option, which gets a new slot, i.e.
existing errors=ro users now get errors=fix_safe.

This is currently only enabled for a limited set of errors - initially
just disk accounting; errors we would never not want to fix, and we
don't want to require user intervention (i.e. to make sure a bug report
gets filed).

Errors will still be counted in the superblock, so we (developers) will
still know they've been occuring if a bug report gets filed (as bug
reports typically include the errors superblock section).

Eventually we'll be enabling this for a much wider set of errors, after
we've done thorough error injection testing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Be more explicit to the user about what we're doing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We've grown a fair amount of code for managing recovery passes; tracking
which ones we're running, which ones need to be run, and flagging in the
superblock which ones need to be run on the next recovery.

So it's worth splitting out into its own file, this code is pretty
different from the code in recovery.c.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This converts -EIOs related to btree node errors to private error codes,
which will help with some ongoing debugging by giving us better error
messages.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>