If an inode has been copied up metadata only, then we need to query the
number of blocks from lower and fill up the stat->st_blocks.
We need to be careful about races where we are doing stat on one cpu and
data copy up is taking place on other cpu. We want to return
stat->st_blocks either from lower or stable upper and not something in
between. Hence, ovl_has_upperdata() is called first to figure out whether
block reporting will take place from lower or upper.
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
fs/overlayfs/inode.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 5239a1ff7211..605308a9d60f 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -76,6 +76,10 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
bool is_dir = S_ISDIR(dentry->d_inode->i_mode);
bool samefs = ovl_same_sb(dentry->d_sb);
int err;
+ bool metacopy = false;
+
+ if (ovl_dentry_upper(dentry) && !ovl_has_upperdata(dentry))
+ metacopy = true;
type = ovl_path_real(dentry, &realpath);
old_cred = ovl_override_creds(dentry->d_sb);
@@ -93,7 +97,8 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
if (!is_dir || samefs) {
if (OVL_TYPE_ORIGIN(type)) {
struct kstat lowerstat;
- u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0);
+ u32 lowermask = STATX_INO | STATX_BLOCKS |
+ (!is_dir ? STATX_NLINK : 0);
ovl_path_lower(dentry, &realpath);
err = vfs_getattr(&realpath, &lowerstat,
@@ -117,6 +122,9 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
WARN_ON_ONCE(stat->dev != lowerstat.dev);
else
stat->dev = ovl_get_pseudo_dev(dentry);
+
+ if (metacopy)
+ stat->blocks = lowerstat.blocks;
}
if (samefs) {
/*
--
2.13.6
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