@@ -2965,7 +2965,9 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
goto out;
}
- err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
+ err = vfs_getattr(&path, &stat,
+ STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
+ AT_STATX_SYNC_AS_STAT);
if (err)
goto out_nfserr;
if (!(stat.result_mask & STATX_BTIME))
@@ -628,6 +628,10 @@ void fh_fill_pre_attrs(struct svc_fh *fhp)
stat.mtime = inode->i_mtime;
stat.ctime = inode->i_ctime;
stat.size = inode->i_size;
+ if (v4 && IS_I_VERSION(inode)) {
+ stat.change_cookie = inode_query_iversion(inode);
+ stat.result_mask |= STATX_CHANGE_COOKIE;
+ }
}
if (v4)
fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode);
@@ -659,6 +663,10 @@ void fh_fill_post_attrs(struct svc_fh *fhp)
if (err) {
fhp->fh_post_saved = false;
fhp->fh_post_attr.ctime = inode->i_ctime;
+ if (v4 && IS_I_VERSION(inode)) {
+ fhp->fh_post_attr.change_cookie = inode_query_iversion(inode);
+ fhp->fh_post_attr.result_mask |= STATX_CHANGE_COOKIE;
+ }
} else
fhp->fh_post_saved = true;
if (v4)
@@ -750,28 +758,38 @@ enum fsid_source fsid_source(const struct svc_fh *fhp)
}
/*
- * We could use i_version alone as the change attribute. However,
- * i_version can go backwards after a reboot. On its own that doesn't
- * necessarily cause a problem, but if i_version goes backwards and then
- * is incremented again it could reuse a value that was previously used
- * before boot, and a client who queried the two values might
- * incorrectly assume nothing changed.
+ * We could use i_version alone as the change attribute. However, i_version
+ * can go backwards on a regular file after an unclean shutdown. On its own
+ * that doesn't necessarily cause a problem, but if i_version goes backwards
+ * and then is incremented again it could reuse a value that was previously
+ * used before boot, and a client who queried the two values might incorrectly
+ * assume nothing changed.
+ *
+ * By using both ctime and the i_version counter we guarantee that as long as
+ * time doesn't go backwards we never reuse an old value. If the filesystem
+ * advertises STATX_ATTR_CHANGE_MONOTONIC, then this mitigation is not
+ * needed.
*
- * By using both ctime and the i_version counter we guarantee that as
- * long as time doesn't go backwards we never reuse an old value.
+ * We only need to do this for regular files as well. For directories, we
+ * assume that the new change attr is always logged to stable storage in some
+ * fashion before the results can be seen.
*/
u64 nfsd4_change_attribute(struct kstat *stat, struct inode *inode)
{
+ u64 chattr;
+
if (inode->i_sb->s_export_op->fetch_iversion)
return inode->i_sb->s_export_op->fetch_iversion(inode);
- else if (IS_I_VERSION(inode)) {
- u64 chattr;
-
- chattr = stat->ctime.tv_sec;
- chattr <<= 30;
- chattr += stat->ctime.tv_nsec;
- chattr += inode_query_iversion(inode);
- return chattr;
- } else
- return time_to_chattr(&stat->ctime);
+ if (stat->result_mask & STATX_CHANGE_COOKIE) {
+ chattr = stat->change_cookie;
+
+ if (S_ISREG(inode->i_mode) &&
+ !(stat->attributes & STATX_ATTR_CHANGE_MONOTONIC)) {
+ chattr += (u64)stat->ctime.tv_sec << 30;
+ chattr += stat->ctime.tv_nsec;
+ }
+ } else {
+ chattr = time_to_chattr(&stat->ctime);
+ }
+ return chattr;
}
@@ -170,9 +170,14 @@ static inline void fh_drop_write(struct svc_fh *fh)
static inline __be32 fh_getattr(const struct svc_fh *fh, struct kstat *stat)
{
+ u32 request_mask = STATX_BASIC_STATS;
struct path p = {.mnt = fh->fh_export->ex_path.mnt,
.dentry = fh->fh_dentry};
- return nfserrno(vfs_getattr(&p, stat, STATX_BASIC_STATS,
+
+ if (fh->fh_maxsize == NFS4_FHSIZE)
+ request_mask |= (STATX_BTIME | STATX_CHANGE_COOKIE);
+
+ return nfserrno(vfs_getattr(&p, stat, request_mask,
AT_STATX_SYNC_AS_STAT));
}