bch_dev->io_ref does not protect against the filesystem going away;
bch_fs->writes does.

Thus the filesystem write ref needs to be the last ref we release.

Reported-by: syzbot+9e0404b505e604f67e41@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

we allow new fields to be added to existing key types, and new versions
should treat them as being zeroed; this was not handled in
alloc_v4_validate.

Reported-by: syzbot+3b2968fa4953885dd66a@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

j->last_empty_seq needs to match j->seq when the journal is empty

Reported-by: syzbot+4093905737cf289b6b38@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

seeing an odd bug where we fail to correctly return an error from
.get_tree():

https://syzkaller.appspot.com/bug?extid=c0360e8367d6d8d04a66

we need to be able to distinguish between accidently returning a
positive error (as implied by the log) and no error.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Reported-by: syzbot+47ecc948aadfb2ab3efc@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Journal replay, in the slowpath where we insert keys in journal order,
was inserting keys in the wrong order; keys from early repair come last.

Reported-by: syzbot+2c4fcb257ce2b6a29d0e@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Fixes: 7a254053 ("bcachefs: support FS_IOC_SETFSLABEL")
Reported-by: syzbot+7e9efdfec27fbde0141d@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

We weren't always so strict about trans->locked state - but now we are,
and new assertions are shaking some bugs out.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Fix another SRCU splat - this one pretty harmless.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

Fixes: 7423330e ("bcachefs: prt_printf() now respects \r\n\t")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Comparing the wrong bpos - this was missed because normally
bucket_gens_init() runs on brand new filesystems, but this bug caused it
to overwrite bucket_gens keys with 0s when upgrading ancient
filesystems.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

On testing on an old mangled filesystem, we missed a case.

Fixes: bd864bc2 ("bcachefs: Fix bch2_trigger_alloc when upgrading from old versions")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

discovered by new trans->locked asserts
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs_effective.* xattrs show the options inherited from parent
directories (as well as explicitly set); this namespace is not for
setting bcachefs options.

Change the .set() handler to a noop so that if e.g. rsync is copying
xattrs it'll do the right thing, and only copy xattrs in the bcachefs.*
namespace. We don't want to return an error, because that will cause
rsync to bail out or get spammy.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

data_update_init() does a bunch of complicated stuff to decide how many
replicas to add, since we only want to increase an extent's durability
on an explicit rereplicate, but extent pointers may be on devices with
different durability settings.

There was a corner case when evacuating a device that had been set to
durability=0 after data had been written to it, and extents on that
device had already been rereplicated - then evacuate only needs to drop
pointers on that device, not move them.

So the assert for !m->op.nr_replicas was spurious; this was a perfectly
legitimate case that needed to be handled.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Factor out some helpers - this function has gotten much too big.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We don't have sufficient information to debug:

https://github.com/koverstreet/bcachefs/issues/726

- print out durability of extent ptrs, when non default
- print the number of replicas we need in data_update_to_text()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fixes:
00488 WARNING: CPU: 9 PID: 194 at mm/page_alloc.c:4410 __alloc_pages_noprof+0x1818/0x1888
00488 Modules linked in:
00488 CPU: 9 UID: 0 PID: 194 Comm: kworker/u66:1 Not tainted 6.11.0-rc1-ktest-g18fa10d6495f #2931
00488 Hardware name: linux,dummy-virt (DT)
00488 Workqueue: writeback wb_workfn (flush-bcachefs-2)
00488 pstate: 20001005 (nzCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
00488 pc : __alloc_pages_noprof+0x1818/0x1888
00488 lr : __alloc_pages_noprof+0x5f4/0x1888
00488 sp : ffffff80ccd8ed00
00488 x29: ffffff80ccd8ed00 x28: 0000000000000000 x27: dfffffc000000000
00488 x26: 0000000000000010 x25: 0000000000000002 x24: 0000000000000000
00488 x23: 0000000000000000 x22: 1ffffff0199b1dbe x21: ffffff80cc680900
00488 x20: 0000000000000000 x19: ffffff80ccd8eed0 x18: 0000000000000000
00488 x17: ffffff80cc58a010 x16: dfffffc000000000 x15: 1ffffff00474e518
00488 x14: 1ffffff00474e518 x13: 1ffffff00474e518 x12: ffffffb8104701b9
00488 x11: 1ffffff8104701b8 x10: ffffffb8104701b8 x9 : ffffffc08043cde8
00488 x8 : 00000047efb8fe48 x7 : ffffff80ccd8ee20 x6 : 0000000000048000
00488 x5 : 1ffffff810470138 x4 : 0000000000000050 x3 : 1ffffff0199b1d94
00488 x2 : ffffffb0199b1d94 x1 : 0000000000000001 x0 : ffffffc082387448
00488 Call trace:
00488  __alloc_pages_noprof+0x1818/0x1888
00488  new_slab+0x284/0x2f0
00488  ___slab_alloc+0x208/0x8e0
00488  __kmalloc_noprof+0x328/0x340
00488  __bch2_writepage+0x106c/0x1830
00488  write_cache_pages+0xa0/0xe8

due to __GFP_NOFAIL without allowing reclaim
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

attempts to retrofit memory safety onto C are increasingly annoying

------------[ cut here ]------------
memcpy: detected field-spanning write (size 4) of single field "&k.replicas" at fs/bcachefs/replicas.c:454 (size 3)
WARNING: CPU: 5 PID: 6525 at fs/bcachefs/replicas.c:454 bch2_replicas_gc2+0x2cb/0x400 [bcachefs]
bch2_replicas_gc2+0x2cb/0x400:
bch2_replicas_gc2 at /home/ojab/src/bcachefs/fs/bcachefs/replicas.c:454 (discriminator 3)
Modules linked in: dm_mod tun nf_conntrack_netlink nfnetlink xt_addrtype br_netfilter overlay msr sctp bcachefs lz4hc_compress lz4_compress libcrc32c xor raid6_pq lz4_decompress pps_ldisc pps_core wireguard libchacha20poly1305 chacha_x86_64 poly1305_x86_64 ip6_udp_tunnel udp_tunnel curve25519_x86_64 libcurve25519_generic libchacha sit tunnel4 ip_tunnel af_packet bridge stp llc ip6table_nat ip6table_filter ip6_tables xt_MASQUERADE xt_conntrack iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter ip_tables x_tables tcp_bbr sch_fq_codel efivarfs nls_iso8859_1 nls_cp437 vfat fat cdc_mbim cdc_wdm cdc_ncm cdc_ether usbnet r8152 input_leds joydev mii amdgpu mousedev hid_generic usbhid hid ath10k_pci amd_atl edac_mce_amd ath10k_core kvm_amd ath kvm mac80211 bfq crc32_pclmul crc32c_intel polyval_clmulni polyval_generic sha512_ssse3 sha256_ssse3 sha1_ssse3 snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg i2c_algo_bit drm_exec snd_hda_codec r8169 drm_suballoc_helper
aesni_intel gf128mul crypto_simd amdxcp realtek mfd_core tpm_crb drm_buddy snd_hwdep mdio_devres libarc4 cryptd tpm_tis wmi_bmof cfg80211 evdev libphy snd_hda_core tpm_tis_core gpu_sched rapl xhci_pci xhci_hcd snd_pcm drm_display_helper snd_timer tpm sp5100_tco rfkill efi_pstore mpt3sas drm_ttm_helper ahci usbcore libaescfb ccp snd ttm 8250 libahci watchdog soundcore raid_class sha1_generic acpi_cpufreq k10temp 8250_base usb_common scsi_transport_sas i2c_piix4 hwmon video serial_mctrl_gpio serial_base ecdh_generic wmi rtc_cmos backlight ecc gpio_amdpt rng_core gpio_generic button
CPU: 5 UID: 0 PID: 6525 Comm: bcachefs Tainted: G        W          6.11.0-rc1-ojab-00058-g224bc118aec9 #6 6d5debde398d2a84851f42ab300dae32c2992027
Tainted: [W]=WARN
RIP: 0010:bch2_replicas_gc2+0x2cb/0x400 [bcachefs]
Code: c7 c2 60 91 d1 c1 48 89 c6 48 c7 c7 98 91 d1 c1 4c 89 14 24 44 89 5c 24 08 48 89 44 24 20 c6 05 fa 68 04 00 01 e8 05 a3 40 e4 <0f> 0b 4c 8b 14 24 44 8b 5c 24 08 48 8b 44 24 20 e9 55 fe ff ff 8b
RSP: 0018:ffffb434c9263d60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9a8efa79cc00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffb434c9263de0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000005
R13: ffff9a8efa73c300 R14: ffff9a8d9e880000 R15: ffff9a8d9e8806f8
FS:  0000000000000000(0000) GS:ffff9a9410c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565423373090 CR3: 0000000164e30000 CR4: 00000000003506f0
Call Trace:
<TASK>
? __warn+0x97/0x150
? bch2_replicas_gc2+0x2cb/0x400 [bcachefs 9803eca5e131ef28f26250ede34072d5b50d98b3]
bch2_replicas_gc2+0x2cb/0x400:
bch2_replicas_gc2 at /home/ojab/src/bcachefs/fs/bcachefs/replicas.c:454 (discriminator 3)
? report_bug+0x196/0x1c0
? handle_bug+0x3c/0x70
? exc_invalid_op+0x17/0x80
? __wake_up_klogd.part.0+0x4c/0x80
? asm_exc_invalid_op+0x16/0x20
? bch2_replicas_gc2+0x2cb/0x400 [bcachefs 9803eca5e131ef28f26250ede34072d5b50d98b3]
bch2_replicas_gc2+0x2cb/0x400:
bch2_replicas_gc2 at /home/ojab/src/bcachefs/fs/bcachefs/replicas.c:454 (discriminator 3)
? bch2_dev_usage_read+0xa0/0xa0 [bcachefs 9803eca5e131ef28f26250ede34072d5b50d98b3]
bch2_dev_usage_read+0xa0/0xa0:
discard_in_flight_remove at /home/ojab/src/bcachefs/fs/bcachefs/alloc_background.c:1712
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Fixes: c2f6e16a ("bcachefs: Increase size of cuckoo hash table on too many rehashes")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We run this in full RW mode now, so we have to guard against the
superblock buffer being reallocated.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Reported-by: syzbot+95e40eae71609e40d851@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Reported-by: syzbot+510b0b28f8e6de64d307@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Reported-by: syzbot+e3938cd6d761b78750e6@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Also, improve the calculation of the new table size, so that it can
shrink when needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This adds another disk accounting counter to track usage per inode
number (any snapshot ID).

This will be used for a couple things:

- It'll give us a way to tell the user how much space a given file ista
  consuming in all snapshots; i.e. how much extra space it's consuming
  due to snapshot versioning.

- It counts number of extents and total size of extents (both in btree
  keyspace sectors and actual disk usage), meaning it gives us average
  extent size: that is, it'll let us cheaply find fragmented files that
  should be defragmented.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

The next patch will be adding a disk accounting counter type which is
not kept in the in-memory eytzinger tree.

As prep, fold __bch2_accounting_mem_mod() into
bch2_accounting_mem_mod_locked() so that we can check for that counter
type and bail out without calling bpos_to_disk_accounting_pos() twice.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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>

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

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

include information about the state of the btree key cache
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This helps ensure key cache reclaim isn't contending with threads
waiting for the key cache to be helped, and fixes a severe performance
bug.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

If we need to increase the tree depth, allocate a new node, and then
race with another thread that increased the tree depth before us, we'll
still have a preallocated node that might be used later.

If we then use that node for a new non-root node, it'll still have a
pointer to the old root instead of being zeroed - fix this by zeroing it
in the cmpxchg failure path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

for_each_btree_node() now works similarly to for_each_btree_key(), where
the loop body is passed as an argument to be passed to lockrestart_do().

This now calls trans_begin() on every loop iteration - which fixes an
SRCU warning in backpointers fsck.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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

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

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

bch2_trigger_alloc was assuming that the new key would always be newly
created and thus always an alloc_v4 key, but - not when called from
btree_gc.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>