From: Jeff Layton <jlayton@xxxxxxxxxx>
Claim one of the spare fields in struct statx to hold a 64-bit change
attribute. When statx requests this attribute, do an
inode_query_iversion and fill the result in the field.
Also update the test-statx.c program to display the change attribute and
the mountid as well.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/stat.c | 7 +++++++
include/linux/stat.h | 1 +
include/uapi/linux/stat.h | 3 ++-
samples/vfs/test-statx.c | 8 ++++++--
4 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/fs/stat.c b/fs/stat.c
index 9ced8860e0f3..7c3d063c31ba 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -17,6 +17,7 @@
#include <linux/syscalls.h>
#include <linux/pagemap.h>
#include <linux/compat.h>
+#include <linux/iversion.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
@@ -118,6 +119,11 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
STATX_ATTR_DAX);
+ if ((request_mask & STATX_CHANGE_ATTR) && IS_I_VERSION(inode)) {
+ stat->result_mask |= STATX_CHANGE_ATTR;
+ stat->change_attr = inode_query_iversion(inode);
+ }
+
mnt_userns = mnt_user_ns(path->mnt);
if (inode->i_op->getattr)
return inode->i_op->getattr(mnt_userns, path, stat,
@@ -611,6 +617,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
tmp.stx_dev_major = MAJOR(stat->dev);
tmp.stx_dev_minor = MINOR(stat->dev);
tmp.stx_mnt_id = stat->mnt_id;
+ tmp.stx_change_attr = stat->change_attr;
return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}
diff --git a/include/linux/stat.h b/include/linux/stat.h
index 7df06931f25d..7b444c2ad0ad 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -50,6 +50,7 @@ struct kstat {
struct timespec64 btime; /* File creation time */
u64 blocks;
u64 mnt_id;
+ u64 change_attr;
};
#endif
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 1500a0f58041..fd839ec76aa4 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -124,7 +124,7 @@ struct statx {
__u32 stx_dev_minor;
/* 0x90 */
__u64 stx_mnt_id;
- __u64 __spare2;
+ __u64 stx_change_attr; /* Inode change attribute */
/* 0xa0 */
__u64 __spare3[12]; /* Spare space for future expansion */
/* 0x100 */
@@ -152,6 +152,7 @@ struct statx {
#define STATX_BASIC_STATS 0x000007ffU /* The stuff in the normal stat struct */
#define STATX_BTIME 0x00000800U /* Want/got stx_btime */
#define STATX_MNT_ID 0x00001000U /* Got stx_mnt_id */
+#define STATX_CHANGE_ATTR 0x00002000U /* Want/got stx_change_attr */
#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */
diff --git a/samples/vfs/test-statx.c b/samples/vfs/test-statx.c
index 49c7a46cee07..b104909721c4 100644
--- a/samples/vfs/test-statx.c
+++ b/samples/vfs/test-statx.c
@@ -107,6 +107,8 @@ static void dump_statx(struct statx *stx)
printf("Device: %-15s", buffer);
if (stx->stx_mask & STATX_INO)
printf(" Inode: %-11llu", (unsigned long long) stx->stx_ino);
+ if (stx->stx_mask & STATX_MNT_ID)
+ printf(" MountId: %llx"), stx->stx_mnt_id;
if (stx->stx_mask & STATX_NLINK)
printf(" Links: %-5u", stx->stx_nlink);
if (stx->stx_mask & STATX_TYPE) {
@@ -145,7 +147,9 @@ static void dump_statx(struct statx *stx)
if (stx->stx_mask & STATX_CTIME)
print_time("Change: ", &stx->stx_ctime);
if (stx->stx_mask & STATX_BTIME)
- print_time(" Birth: ", &stx->stx_btime);
+ print_time("Birth: ", &stx->stx_btime);
+ if (stx->stx_mask & STATX_CHANGE_ATTR)
+ printf(" Change Attr: 0x%llx\n", stx->stx_change_attr);
if (stx->stx_attributes_mask) {
unsigned char bits, mbits;
@@ -218,7 +222,7 @@ int main(int argc, char **argv)
struct statx stx;
int ret, raw = 0, atflag = AT_SYMLINK_NOFOLLOW;
- unsigned int mask = STATX_BASIC_STATS | STATX_BTIME;
+ unsigned int mask = STATX_BASIC_STATS | STATX_BTIME | STATX_MNT_ID | STATX_CHANGE_ATTR;
for (argv++; *argv; argv++) {
if (strcmp(*argv, "-F") == 0) {
--
2.37.2
