[LU-15579] When nfs exports lustre, chmod the strip directory under the strip directory will have a Permission Deny occurs error

Related — Mon, 8 Aug 2022 09:34:52 +0000

nfs server(lustre client)：

# lfs getdirstripe test
lmv_stripe_count: 8 lmv_stripe_offset: 0 lmv_hash_type: fnv_1a_64
mdtidx           FID[seq:oid:ver]
     0           [0x200000400:0xe:0x0]
     1           [0x7c0000407:0xe:0x0]
     2           [0x280000405:0xe:0x0]
     3           [0x240000405:0xe:0x0]
     4           [0x340000403:0xe:0x0]
     5           [0x2c0000405:0xe:0x0]
     6           [0x380000404:0xe:0x0]
     7           [0x300000403:0xe:0x0] 

# cd test
# ls
debug
# lfs getdirstripe debug
lmv_stripe_count: 8 lmv_stripe_offset: 0 lmv_hash_type: fnv_1a_64
mdtidx           FID[seq:oid:ver]
     0           [0x200000bd0:0x4:0x0]
     1           [0x7c0000bd1:0x4:0x0]
     2           [0x280000bd1:0x4:0x0]
     3           [0x240000bd1:0x4:0x0]
     4           [0x340000bd1:0x4:0x0]
     5           [0x2c0000bd2:0x4:0x0]
     6           [0x380000bd1:0x4:0x0]
     7           [0x300000bd1:0x4:0x0]

nfs client:

# cd /mnt/nfs3/test
# ls
debug
# chmod 755 debug
# ls
ls: cannot access debug: Permission denied
ls: reading directory .: Permission denied
debug
# ls
ls: reading directory .: Permission denied

When I execute ls in the directory of the nfs server, the nfs client ls can return to normal

nfs server(lustre client)：

# pwd
/muzitest/test
# ls
debug

nfs client:

# ls
debug

I tried to check on the nfs server (lustre client) and found that the parent_fid in ll_dir_get_parent_fid was incorrectly obtained. This function should correctly obtain the fid of the parent directory of debug, but it lacked the fid of debug itself.

Therefore, I started to investigate the code on the server side and found that the step to return the debug directory fid is in the mdt_raw_lookup function:

The mdo_lookup call chain is as follows:

mdt_raw_lookup --> mdd_lookup --> dio_lookup --> lod_lookup --> osd_index_ea_lookup --> osd_ea_lookup_rec

In the osd_ea_lookup_rec function, I found that the fid is obtained in the osd_get_fid_from_dentry function, and the content of struct ldiskfs_dir_entry_2 *de is filled in osd_ldiskfs_find_entry. But I can't find the code related to osd_ldiskfs_find_entry in the source code, so I can't analyze it further.

Whamcloud Community JIRA

[LU-15579] When nfs exports lustre, chmod the strip directory under the strip directory will have a Permission Deny occurs error