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cxl-micron-reskit / famfs

This is the user space repo for famfs, the fabric-attached memory file system
Apache License 2.0
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mkfs.famfs: segfault in get_role if dax device is in system-ram mode #46

Open jagalactic opened 5 months ago

jagalactic commented 5 months ago

This should be fixed, but the workaround is put your dax device in a valid state and try again

jagalactic commented 5 months ago

The raw mmap of superblock and log from (e.g.) /dev/dax0.0 succeeds, but the attempt to clflush to those addresses causes a segfault. Q: why does the mmap succeed when the dev is in system-ram mode?

jagalactic commented 3 months ago

Just re-checked this issue, and I'm not seeing the segfault - so this may no longer be an issue.

[root@onr02 ~]# daxctl list
[
  {
    "chardev":"dax1.0",
    "size":34359738368,
    "target_node":2,
    "align":2097152,
    "mode":"system-ram",
    "online_memblocks":0,
    "total_memblocks":16
  },
  {
    "chardev":"dax2.0",
    "size":34359738368,
    "target_node":3,
    "align":2097152,
    "mode":"system-ram",
    "online_memblocks":0,
    "total_memblocks":16
  },
  {
    "chardev":"dax0.0",
    "size":541163782144,
    "target_node":0,
    "align":2097152,
    "mode":"devdax"
  }
]
[root@onr02 ~]# mkfs.famfs /dev/dax2.0
famfs_mmap_superblock_and_log_raw: open /dev/dax2.0 failed; rc 0 errno 6
famfs_mkfs: failed to establish role
[root@onr02 ~]#