fsck.f2fs: add a sanity check in update_data_blkaddr()

[   16.609296][  T423] fsck.f2fs: [ASSERT] (get_sum_block:2422)  --> segno [0x222c] indicates a data segment, but should be node
[   16.609300][  T423] fsck.f2fs: [ASSERT] (get_sum_block:2422)  --> segno [0x222c] indicates a data segment, but should be node
[   16.609318][  T423] fsck.f2fs: [ASSERT] (get_sum_block:2422)  --> segno [0x222c] indicates a data segment, but should be node
[   16.609323][  T423] fsck.f2fs: [ASSERT] (get_sum_block:2422)  --> segno [0x222c] indicates a data segment, but should be node
[   16.609329][  T423] fsck.f2fs: [ASSERT] (get_sum_block:2422)  --> segno [0x222c] indicates a data segment, but should be node
[   16.609332][  T423] fsck.f2fs: [ASSERT] (get_sum_block:2422)  --> segno [0x222c] indicates a data segment, but should be node

[   16.706176][  T574] DEBUG: Executable: /system/bin/fsck.f2fs
[   16.706347][  T574] DEBUG: Cmdline: /system/bin/fsck.f2fs -a -c 10000 --debug-cache --nolinear-lookup=1 /dev/block/mapper/userdata
[   16.706519][  T574] DEBUG: pid: 531, ppid: 423, tid: 531, name: fsck.f2fs  >>> /system/bin/fsck.f2fs <<<
[   16.706687][  T574] DEBUG: uid: 0
[   16.706861][  T574] DEBUG: tagged_addr_ctrl: 0000000000000001 (PR_TAGGED_ADDR_ENABLE)
[   16.707035][  T574] DEBUG: pac_enabled_keys: 000000000000000f (PR_PAC_APIAKEY, PR_PAC_APIBKEY, PR_PAC_APDAKEY, PR_PAC_APDBKEY)
[   16.707360][  T574] DEBUG: esr: 0000000092000007 (Data Abort Exception 0x24)
[   16.707520][  T574] DEBUG: signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0000007fe0d0afd0 (read)
[   16.707674][  T574] DEBUG: Cause: stack pointer is in a non-existent map; likely due to stack overflow.
[   16.707832][  T574] DEBUG:     x0  00000056d9adcc08  x1  0000007fe0d0c0b8  x2  0000000000000000  x3  0000000000000001
[   16.707987][  T574] DEBUG:     x4  0000000000000000  x5  00000056d9ad4000  x6  00000056d9adc000  x7  00000056d9adc000
[   16.708141][  T574] DEBUG:     x8  0000000000000040  x9  0000000000000001  x10 0000000000001000  x11 0000007fe0d0afd0
[   16.708296][  T574] DEBUG:     x12 0000000000001000  x13 0000000000000009  x14 000000000008c015  x15 00000000000004bc
[   16.708564][  T574] DEBUG:     x16 b400007b0e7ea780  x17 b4000078fa60e870  x18 0000007b0ea08000  x19 00000000004d184c
[   16.708741][  T574] DEBUG:     x20 00000056d9adcc08  x21 0000007fe0d0bfd0  x22 0000007fe0d0afd0  x23 00000056d9ad4954
[   16.708914][  T574] DEBUG:     x24 0000000000000001  x25 b400007a6a60b9d0  x26 0000000000000037  x27 0000000000000001
[   16.709108][  T574] DEBUG:     x28 0000000000000000  x29 0000007fe0d0c050
[   16.709262][  T574] DEBUG:     lr  005b0fd6d9aba138  sp  0000007fe0d0afd0  pc  00000056d9aaf8a0  pst 0000000060001000
[   16.709416][  T574] DEBUG:     esr 0000000092000007  vg  0000000000000002
[   16.709571][  T574] DEBUG: 512 total frames
[   16.709723][  T574] DEBUG: backtrace:
[   16.710133][  T574] DEBUG:       #00 pc 000000000002f8a0  /system/bin/fsck.f2fs (find_next_free_block+192) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.710482][  T574] DEBUG:       #01 pc 000000000003a134  /system/bin/fsck.f2fs (update_block+276) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.710695][  T574] DEBUG:       #02 pc 000000000002e5e8  /system/bin/fsck.f2fs (update_data_blkaddr+296) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.710875][  T574] DEBUG:       #03 pc 000000000003a250  /system/bin/fsck.f2fs (update_block+560) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)

... (loop)

[   16.806359][  T574] DEBUG:       #505 pc 000000000003a250  /system/bin/fsck.f2fs (update_block+560) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.806544][  T574] DEBUG:       #506 pc 000000000002e5e8  /system/bin/fsck.f2fs (update_data_blkaddr+296) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.806730][  T574] DEBUG:       #507 pc 000000000003a250  /system/bin/fsck.f2fs (update_block+560) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.806915][  T574] DEBUG:       #508 pc 000000000002e5e8  /system/bin/fsck.f2fs (update_data_blkaddr+296) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.807101][  T574] DEBUG:       #509 pc 000000000003a250  /system/bin/fsck.f2fs (update_block+560) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.807293][  T574] DEBUG:       #510 pc 000000000002e5e8  /system/bin/fsck.f2fs (update_data_blkaddr+296) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.807478][  T574] DEBUG:       #511 pc 000000000003a250  /system/bin/fsck.f2fs (update_block+560) (BuildId: e2a4d8d81fcb93e518e8bc64f8df050d)
[   16.807665][  T574] DEBUG: Note: To display stack pointer information, use the pbtombstone tool:

If there is inconsistent status in between SIT and node segment:
1. SIT indicate the segment is data type
2. a node block locates in the segment

It will cause deadloop w/ below patern:

a) fsck call update_block() to update the node block to a newly allocated
blkaddr, however it finds the node is in data segment, so it treat the node
block as data block, then calling update_data_blkaddr() to update it to a
new blkaddr.
b) in update_data_blkaddr(), because node_blk is NULL, so it treats the
newaddr as block address of data block, then calling update_block() to
update metadata of target data block.

This patch adds a sanity check in update_data_blkaddr() to detect such
inconsistency and end up w/ log and ASSERT().

Signed-off-by: Chao Yu <chao@kernel.org>