[LU-10787] setxattr(..., XATTR_REPLACE) removes rather than replaces the attribute

Related — Wed, 6 Dec 2023 17:40:49 +0000

(setfattr does not allow us to specify XATTR_REPLACE so I used a custom utility.)

n:lustre# rm f0
n:lustre# touch f0
n:lustre# setfattr -n user.foo -v foo f0
n:lustre# getfattr -d f0
# file: f0
user.foo="foo"

n:lustre# setfattr -n user.foo -v bar f0
n:lustre# getfattr -d f0
# file: f0
user.foo="bar"

n:lustre# strace -e trace=setxattr ~/sys/sys_setxattr -r f0 user.foo baz
setxattr("f0", "user.foo", "baz", 3, XATTR_REPLACE) = 0
+++ exited with 0 +++
n:lustre# getfattr -d f0
n:lustre#

This is due to ll_xattr_set_common() using OBD_MD_FLXATTRRM for XATTR_REPLACE:

       if (flags == XATTR_REPLACE) {
                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_REMOVEXATTR, 1);
                valid = OBD_MD_FLXATTRRM;
        } else {
                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_SETXATTR, 1);
                valid = OBD_MD_FLXATTR;
        }

Whamcloud Community JIRA

[LU-10787] setxattr(..., XATTR_REPLACE) removes rather than replaces the attribute