- bch2_sb_downgrade_validate() wasn't checking for a downgrade entry
  extending past the end of the superblock section

- for_each_downgrade_entry() is used in to_text() and needs to work on
  malformed input; it also was missing a check for a field extending
  past the end of the section

Reported-by: syzbot+e49ccab73449180bc9be@syzkaller.appspotmail.com
Fixes: 84f16387 ("bcachefs: bch_sb_field_downgrade")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

We're about to start using bch_validate_flags for superblock section
validation - it's no longer bkey specific.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fsync has a slightly odd usage of -EROFS, where it means "does not
support fsync". I didn't choose it...
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

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

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

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

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

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

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

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

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

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

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

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

Move BCACHEFS_STATFS_MAGIC value to UAPI <linux/magic.h> under
BCACHEFS_SUPER_MAGIC definition (use common approach for name) and reuse the
definition in bcachefs_format.h BCACHEFS_STATFS_MAGIC.

There are other bcachefs magic definitions: BCACHE_MAGIC, BCHFS_MAGIC,
which use UUID_INIT() and are used only in libbcachefs. Therefore move
only BCACHEFS_STATFS_MAGIC value, which can be used outside of
libbcachefs for f_type field in struct statfs in statfs() or fstatfs().
Suggested-by: Su Yue <glass.su@suse.com>
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Acked-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

We now have a small bitmap in the member info section of the superblock
for "regions that have btree nodes", so that if we ever have to scan for
btree nodes in repair we don't have to scan the whole device(s).

This tweaks the allocator to prefer allocating from regions that are
already marked in this bitmap.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Tracepoints are garbage, and perf trace even cuts off some of our
fields.

Much nicer to just trace a string, and then we can build nicely
formatted output with printbufs.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This fixes a lifetime issue; bch2_nocow_write_unlock() uses
PTR_BUCKET_POS(), which needs the device - but we drop our ref to the
device in bch2_write_endio().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

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

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

bch2_dev_bkey_exists() is going away; bch2_dev_have_ref() documents that
we're looking up a device without checking if it's present because we
have a reference to it already.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

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

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

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

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

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

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

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

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

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

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

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

Wrapper around bch2_dev_have_ref() for open_buckets; we do guarantee
that the device an open_bucket points to exists.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This is needed for the next patch - the write submit path has to be able
to allocate a replica bio even when we weren't able to get a ref on the
device.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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