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

This factors out ec_strie_head_devs_update(), which initializes the
bitmap of devices we're allocating from, and runs it every time
c->rw_devs_change_count changes.

We also cancel pending, not allocated stripes, since they may refer to
devices that are no longer available.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Add a counter that's incremented whenever rw devices change; this will
be used for erasure coding so that it can keep ec_stripe_head in sync
and not deadlock on a new stripe when a device it wants goes away.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We can now correctly force-remove a device that has stripes on it; this
uses the new BCH_SB_MEMBER_INVALID sentinal value.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This is necessary for erasure coded pointers to devices that have been
removed.
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>

also print out the new stripe key
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

When reshaping existing stripes, we should keep them on the same target
that they were allocated on; to do this, we need to add a field to the
btree stripe type.

This is a tad awkward, because we only have 8 bits left, and targets are
16 bits - but we only need to store a label, not a full target.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

factor out a common helper
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We want to be using private errcodes whenever possible, for better error
messages.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

In backpointers fsck, we do a seqential scan of one btree, and check
references to another: extents <-> backpointers

Checking references generates random lookups, so we want to pin that
btree in memory (or only a range, if it doesn't fit in ram).

Previously, this was done with a simple check in the shrinker - "if
btree node is in range being pinned, don't free it" - but this generated
OOMs, as our shrinker wasn't well behaved if there was less memory
available than expected.

Instead, we now have two different shrinkers and lru lists; the second
shrinker being for pinned nodes, with seeks set much higher than normal
- so they can still be freed if necessary, but we'll prefer not to.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

this is prep for introducing a second live list and shrinker for pinned
nodes
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

32 bits won't overflow any time soon, but size_t is the correct type for
counting objects in memory.
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_rcu() now properly errors if the device is invalid
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

Factor out bch2_show_options() into a generic helper, for debugging
option passing issues.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

Fix the following compilation error:

```
fs/bcachefs/sb-members.c: In function ‘bch2_sb_member_alloc’:
fs/bcachefs/sb-members.c:508:2: error: a label can only be part of a statement and a declaration is not a statement
  508 |  unsigned nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
```

Fixes: a7d364a133c7 ("bcachefs: bch2_sb_member_alloc()")
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

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

No reason for it not to be where it's needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This adds mount options for specifying recovery passes to run, or
exclude; the immediate need for this is that backpointers fsck is having
trouble completing, so we need a way to skip it.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

When freeing in a shrinker callback, we need to notify memory reclaim,
so it knows forward progress has been made.

Normally this is done in e.g. slab code, but we're not freeing through
slab - or rather we are, but these allocations are big, and use the
kmalloc_large() path.

This is really a bug in the slub code, but we're working around it here
for now.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

This is needed for overlayfs, which is used by container managers.
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

this was an oversight: rebalance is moving data to a specific device, so
we don't want it falling back to the full filesystem
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

rebalance writes must be BCH_WRITE_ALLOC_NOWAIT because they don't
allocate from the full filesystem - but we don't want spurious
allocation failures due to open buckets.
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>

like the previous patch, kill use of bare arrays; the encryption code
likes to work in big batches, so this is a small performance
improvement.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

convert to darray, and add a fallback when allocation fails
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

Add the __counted_by compiler attribute to the flexible array members
devs to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Increment nr_devs before adding a new device to the devs array and
adjust the array indexes accordingly. Add a helper macro for adding a
new device.

In bch2_journal_read(), explicitly set nr_devs to 0.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We enable idmapped mounts for bcachefs. Here, we just pass down
the user_namespace argument from the VFS methods to the relevant
helpers.

The idmap test in bcachefs is as following:

```
1. losetup /dev/loop1 bcachefs.img
2. ./bcachefs format /dev/loop1
3. mount -t bcachefs /dev/loop1 /mnt/bcachefs/
4. ./mount-idmapped --map-mount b:0:1000:1 /mnt/bcachefs /mnt/idmapped1/

ll /mnt/bcachefs
total 2
drwx------. 2 root root    0 Jun 14 14:10 lost+found
-rw-r--r--. 1 root root 1945 Jun 14 14:12 profile

ll /mnt/idmapped1/

total 2
drwx------. 2 1000 1000    0 Jun 14 14:10 lost+found
-rw-r--r--. 1 1000 1000 1945 Jun 14 14:12 profile
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Add the __counted_by compiler attribute to the flexible array member
x_name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

A user with a 30 tb device is overflowing the INT_MAX limit on vmalloc
allocations...
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>