Viewing: llapi_hsm_data_version_set.3
.TH LLAPI_HSM_DATA_VERSION_SET 3 2025-12-22 "Lustre User API" "Lustre Library Functions"
.SH NAME
llapi_hsm_data_version_set \- set OST data version to HSM xattr
.SH SYNOPSIS
.nf
.B #include <lustre/lustreapi.h>
.sp
.BI "int llapi_hsm_data_version_set(int " fd ", __u64 " data_version );
.YS
.fi
.SH DESCRIPTION
Update the file's data version and store it in the
.B trusted.hsm
xattr on the file after doing some file data migration operation
that does not affect the data contents.
.PP
The data version is typically fetched via
.BR llapi_get_data_version (3),
which should be referenced for details about data version.
.TP
.I fd
open file descriptor
.TP
.I data_version
64-bit integer that contains the file data version.
.SH RETURN VALUES
.BR llapi_hsm_data_version_set ()
returns:
.TP
0
on success
.TP
<0
a negative errno value on failure
.SH EXAMPLES
.EX
int fd_src;
__u64 dv1, dv2;
\&
fd_src = open(filename, O_RDONLY);
rc = llapi_get_data_version(fd_src, &dv1, 0);
/* manage the file data - migrate, mirror, etc. */
rc = llapi_get_data_version(fd_src, &dv2, LL_DV_RD_FLUSH);
close(fd_src);
if (dv1 == dv2)
llapi_hsm_data_version_set(fd_src, dv2);
.EE
.SH AVAILABILITY
The
.BR llapi_hsm_data_version_set ()
API is part of the
.BR lustre (7)
user application interface library since release 2.16.0.
.\" Added in commit v2_15_90-10-g80a961261a23
.SH SEE ALSO
.BR lfs-data_version (1),
.BR lfs-migrate (1),
.BR llapi_fswap_layouts (3),
.BR llapi_fsync (3),
.BR llapi_hsm_data_version_set (3),
.BR lustre (7),
.BR lustreapi (7)
