[LU-8034] HSM: Symlink in shadow directory links to a wrong path when archiving files managed by MDT1

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.8.0
• Type: Bug
• Priority: Major
• Reporter: Tatsushi Takamura
• Assignee: Robert Read (Inactive)
• Resolution: Duplicate
• Labels: HSM
• Severity: 3
• Project: HSM

Description

Symlink in shadow directory links to a wrong path when archiving files managed by MDT1(right path when by MDT0).

To reproduce:

[Clinet]
# mkdir /lustre/mdt0_dir
# lfs mkdir -i 1 /lustre/mdt1_dir/
# echo aaa > /lustre/mdt0_dir/file
# echo aaa > /lustre/mdt1_dir/file
# lfs hsm_archive /lustre/mdt0_dir/file
# lfs hsm_archive /lustre/mdt1_dir/file

[Agent]
# ls -l /mnt/hsm-arc/shadow/mdt0_dir/file
lrwxrwxrwx 1 root root 55 Apr 15 16:04 /mnt/hsm-arc/shadow/mdt0_dir/file -> ../../0006/0000/0403/0000/0002/0000/0x200000403:0x6:0x0
# ls -l /mnt/hsm-arc/shadow/mdt1_dir/file
lrwxrwxrwx 1 root root 58 Apr 15 16:04 /mnt/hsm-arc/shadow/mdt1_dir/file -> ../../../0002/0000/0403/4000/0002/0000/0x240000403:0x2:0x0

This is because lhsmtool_posix counts the number of "/" to figure out how many parent directories to symlink back.
But, llapi_fid2path() adds the pathname to an extra "/" in the case of files managed by MDT1.
So, the symlink links to a wrong path
(This may be a llapi_fid2path's bug).

                ptr = opt.o_hsm_root;
                while (*ptr)
                        (*ptr++ == '/') ? depth-- : 0;

                rc = llapi_fid2path(opt.o_mnt, buf, src + strlen(src),
                                    sizeof(src) - strlen(src), &recno, &linkno);


                /* Figure out how many parent dirs to symlink back */
                ptr = src;
                while (*ptr)
                        (*ptr++ == '/') ? depth++ : 0;
                sprintf(buf, "..");
                while (--depth > 1)
                        strcat(buf, "/..");

[Clinet]
# lfs fid2path /lustre/ 0x200000403:0x6:0x0
/lustre/mdt0_dir/file
# lfs fid2path /lustre/ 0x240000403:0x2:0x0
/lustre//mdt1_dir/file

Comments

[Robert Read (Inactive)]

Since llapi_fid2path returns relative paths it probably shouldn't be adding any leading '/' anyway.

[John Hammond]

This issue exists in 2.8.0 but not in 2.9.0. Not sure why exactly.

[Tatsushi Takamura]

I have confirmed that this issue is resolved applying the patch of LU-28.

Thanks.

[Peter Jones]

Thanks for confirming