Re: [RFC PATCH 1/4] vfs: report change attribute in statx for IS_I_VERSION inodes

Also update the test-statx.c program to fetch the change attribute as
well.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/stat.c                 | 7 +++++++
 include/linux/stat.h      | 1 +
 include/uapi/linux/stat.h | 3 ++-
 samples/vfs/test-statx.c  | 4 +++-
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/fs/stat.c b/fs/stat.c
index 9ced8860e0f3..976e0a59ab23 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_CHGATTR) && IS_I_VERSION(inode)) {
+               stat->result_mask |= STATX_CHGATTR;
+               stat->chgattr = 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_chgattr = stat->chgattr;

        return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }

diff --git a/include/linux/stat.h b/include/linux/stat.h
index 7df06931f25d..4a17887472f6 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             chgattr;
 };

 #endif

diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 1500a0f58041..b45243a0fbc5 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_chgattr;    /* 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_CHGATTR          0x00002000U     /* Want/git stx_chgattr */

 #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..767208d2f564 100644
--- a/samples/vfs/test-statx.c
+++ b/samples/vfs/test-statx.c

@@ -109,6 +109,8 @@ static void dump_statx(struct statx *stx)
                printf(" Inode: %-11llu", (unsigned long long) stx->stx_ino);
        if (stx->stx_mask & STATX_NLINK)
                printf(" Links: %-5u", stx->stx_nlink);
+       if (stx->stx_mask & STATX_CHGATTR)
+               printf(" Change Attr: 0x%llx", stx->stx_chgattr);
        if (stx->stx_mask & STATX_TYPE) {
                switch (stx->stx_mode & S_IFMT) {
                case S_IFBLK:

@@ -218,7 +220,7 @@ 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_CHGATTR;

        for (argv++; *argv; argv++) {
                if (strcmp(*argv, "-F") == 0) {
--

2.37.1