Link st_ino not match

[wayne70211]

st_ino not the same when stat

When ln /mnt/a.txt /mnt/b.txt and call stat /mnt/a.txt and stat /mnt/b.txt
It should be same st_ino but is not equal.

Test Flow

1. echo "Hello" > /mnt/a.txt
2. ln /mnt/a.txt /mnt/b.txt
3. stat -s /mnt/a.txt
4. stat -s /mnt/b.txt

From hexdump -C waynefs.img

Step 1: Create and write "Hello" to /mnt/a.txt

00000000  57 41 59 4e 45 5f 46 53  00 10 00 00 00 40 00 00  |WAYNE_FS.....@..|
00000010  00 04 00 00 01 00 00 00  01 00 00 00 02 00 00 00  |................|
00000020  01 00 00 00 03 00 00 00  20 00 00 00 23 00 00 00  |........ ...#...|
00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00001000  03 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00001010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00002000  ff ff ff ff 1f 00 00 00  00 00 00 00 00 00 00 00  |................|
00002010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00003000  00 40 00 00 02 00 00 00  1e 00 00 00 00 00 00 00  |.@..............|
00003010  35 bb e2 68 00 00 00 00  35 bb e2 68 00 00 00 00  |5..h....5..h....|
00003020  24 bb e2 68 00 00 00 00  23 00 00 00 00 00 00 00  |$..h....#.......|
00003030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00003080  a4 81 00 00 01 00 00 00  06 00 00 00 00 00 00 00  |................|
00003090  35 bb e2 68 00 00 00 00  35 bb e2 68 00 00 00 00  |5..h....5..h....|
000030a0  35 bb e2 68 00 00 00 00  24 00 00 00 00 00 00 00  |5..h....$.......|
000030b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00023000  1a 00 00 00 00 00 00 00  01 00 2e 00 00 00 00 02  |................|
00023010  00 2e 2e 01 00 00 00 05  00 61 2e 74 78 74 00 00  |.........a.txt..|
00023020  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00024000  48 65 6c 6c 6f 0a 00 00  00 00 00 00 00 00 00 00  |Hello...........|
00024010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|

Step 2: Link /mnt/b.txt to /mnt/a.txt

00000000  57 41 59 4e 45 5f 46 53  00 10 00 00 00 40 00 00  |WAYNE_FS.....@..|
00000010  00 04 00 00 01 00 00 00  01 00 00 00 02 00 00 00  |................|
00000020  01 00 00 00 03 00 00 00  20 00 00 00 23 00 00 00  |........ ...#...|
00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00001000  03 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00001010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00002000  ff ff ff ff 1f 00 00 00  00 00 00 00 00 00 00 00  |................|
00002010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00003000  00 40 00 00 02 00 00 00  29 00 00 00 00 00 00 00  |.@......).......|
00003010  9a bb e2 68 00 00 00 00  9a bb e2 68 00 00 00 00  |...h.......h....|
00003020  24 bb e2 68 00 00 00 00  23 00 00 00 00 00 00 00  |$..h....#.......|
00003030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00003080  a4 81 00 00 02 00 00 00  06 00 00 00 00 00 00 00  |................|
00003090  9a bb e2 68 00 00 00 00  35 bb e2 68 00 00 00 00  |...h....5..h....|
000030a0  35 bb e2 68 00 00 00 00  24 00 00 00 00 00 00 00  |5..h....$.......|
000030b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00023000  25 00 00 00 00 00 00 00  01 00 2e 00 00 00 00 02  |%...............|
00023010  00 2e 2e 01 00 00 00 05  00 61 2e 74 78 74 01 00  |.........a.txt..|
00023020  00 00 05 00 62 2e 74 78  74 00 00 00 00 00 00 00  |....b.txt.......|
00023030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00024000  48 65 6c 6c 6f 0a 00 00  00 00 00 00 00 00 00 00  |Hello...........|
00024010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|

In data block, there are only one Hello data
From Inode BMP at 0x1000, it doesn't allocate a new inode

Step 3: Check /mnt/a.txt st_ino and st_nlink

st_dev=905969719 st_ino=2 st_mode=0100644 st_nlink=2 st_uid=0 st_gid=0 st_rdev=0 st_size=6 st_atime=1759689525 st_mtime=1759689525 st_ctime=1759689626 st_birthtime=0 st_blksize=65536 st_blocks=32 st_flags=0

Step 4: Check /mnt/b.txt st_ino and st_nlink

st_dev=905969719 st_ino=3 st_mode=0100644 st_nlink=2 st_uid=0 st_gid=0 st_rdev=0 st_size=6 st_atime=1759689525 st_mtime=1759689525 st_ctime=1759689626 st_birthtime=0 st_blksize=65536 st_blocks=32 st_flags=0

Issue

The st_ino should be the same and it also the same from getattr by debug info.
But in the stat, the st_ino are not the same

I write a new data to /mnt/a.txt and check if the /mnt/b.txt is also be modified. It works, it means the inode is the same between /mnt/a.txt and /mnt/b.txt

[wayne70211]

Same issue found in Linux 6.8.0-88-generic

Step 3: Check /mnt/a.txt st_ino and st_nlink

  File: ./mnt/a.txt
  Size: 6         	Blocks: 0          IO Block: 4096   regular file
Device: 0,48	Inode: 2           Links: 2
Access: (0664/-rw-rw-r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2025-12-11 17:05:26.000000000 +0000
Modify: 2025-12-11 17:05:26.000000000 +0000
Change: 2025-12-11 17:05:50.000000000 +0000
 Birth: -

Step 4: Check /mnt/b.txt st_ino and st_nlink

  File: ./mnt/b.txt
  Size: 6         	Blocks: 0          IO Block: 4096   regular file
Device: 0,48	Inode: 3           Links: 2
Access: (0664/-rw-rw-r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2025-12-11 17:05:26.000000000 +0000
Modify: 2025-12-11 17:05:26.000000000 +0000
Change: 2025-12-11 17:05:50.000000000 +0000
 Birth: -