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authorMiklos Szeredi <mszeredi@redhat.com>2017-09-05 12:53:11 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2017-09-05 12:53:11 +0200
commitcd91304e7190b4c4802f8e413ab2214b233e0260 (patch)
tree66a616319703171a07055fed8f6db52cd3f14c5a
parent495e642939114478a5237a7d91661ba93b76f15a (diff)
downloadlwn-cd91304e7190b4c4802f8e413ab2214b233e0260.tar.gz
lwn-cd91304e7190b4c4802f8e413ab2214b233e0260.zip
ovl: fix relatime for directories
Need to treat non-regular overlayfs files the same as regular files when checking for an atime update. Add a d_real() flag to make it return the upper dentry for all file types. Reported-by: "zhangyi (F)" <yi.zhang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
-rw-r--r--fs/inode.c21
-rw-r--r--fs/overlayfs/super.c3
-rw-r--r--include/linux/dcache.h3
3 files changed, 23 insertions, 4 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 50370599e371..eed15033e36b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1569,11 +1569,24 @@ EXPORT_SYMBOL(bmap);
static void update_ovl_inode_times(struct dentry *dentry, struct inode *inode,
bool rcu)
{
- if (!rcu) {
- struct inode *realinode = d_real_inode(dentry);
+ struct dentry *upperdentry;
- if (unlikely(inode != realinode) &&
- (!timespec_equal(&inode->i_mtime, &realinode->i_mtime) ||
+ /*
+ * Nothing to do if in rcu or if non-overlayfs
+ */
+ if (rcu || likely(!(dentry->d_flags & DCACHE_OP_REAL)))
+ return;
+
+ upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER);
+
+ /*
+ * If file is on lower then we can't update atime, so no worries about
+ * stale mtime/ctime.
+ */
+ if (upperdentry) {
+ struct inode *realinode = d_inode(upperdentry);
+
+ if ((!timespec_equal(&inode->i_mtime, &realinode->i_mtime) ||
!timespec_equal(&inode->i_ctime, &realinode->i_ctime))) {
inode->i_mtime = realinode->i_mtime;
inode->i_ctime = realinode->i_ctime;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 19e89ce39017..cd49c0298ddf 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -75,6 +75,9 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
struct dentry *real;
int err;
+ if (flags & D_REAL_UPPER)
+ return ovl_dentry_upper(dentry);
+
if (!d_is_reg(dentry)) {
if (!inode || inode == d_inode(dentry))
return dentry;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index fd0721e520f4..ed1a7cf6923a 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -562,6 +562,9 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper)
return upper;
}
+/* d_real() flags */
+#define D_REAL_UPPER 0x2 /* return upper dentry or NULL if non-upper */
+
/**
* d_real - Return the real dentry
* @dentry: the dentry to query