Now we will have the capability to have upper inodes which might be only
metadata copy up and data is still on lower inode. So add a new xattr
OVL_XATTR_METACOPY to distinguish between two cases.
Presence of OVL_XATTR_METACOPY reflects that file has been copied up metadata
only and and data will be copied up later from lower origin.
So this xattr is set when a metadata copy takes place and cleared when
data copy takes place.
We also use a bit in ovl_inode->flags to cache OVL_UPPERDATA which reflects
whether ovl inode has data or not (as opposed to metadata only copy up).
Note, OVL_UPPERDATA is set only on those upper inodes which can possibly
be metacopy only inodes. For example, inode should be a regular file and
there needs to be a lower dentry.
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
fs/overlayfs/copy_up.c | 55 +++++++++++++++++++++++++++++++++++++++++++++---
fs/overlayfs/inode.c | 3 ++-
fs/overlayfs/overlayfs.h | 6 +++++-
fs/overlayfs/util.c | 34 ++++++++++++++++++++++++++++--
4 files changed, 91 insertions(+), 7 deletions(-)
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 2936284..a6cda02 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -196,6 +196,16 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
return error;
}
+static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat)
+{
+ struct iattr attr = {
+ .ia_valid = ATTR_SIZE,
+ .ia_size = stat->size,
+ };
+
+ return notify_change(upperdentry, &attr, NULL);
+}
+
static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
{
struct iattr attr = {
@@ -439,6 +449,28 @@ static int ovl_get_tmpfile(struct ovl_copy_up_ctx *c, struct dentry **tempp)
goto out;
}
+/* Copy up data of an inode which was copied up metadata only in the past. */
+static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c)
+{
+ struct path upperpath;
+ int err;
+
+ ovl_path_upper(c->dentry, &upperpath);
+ if (WARN_ON(upperpath.dentry == NULL))
+ return -EIO;
+
+ err = ovl_copy_up_data(&c->lowerpath, &upperpath, c->stat.size);
+ if (err)
+ return err;
+
+ err= vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);
+ if (err)
+ return err;
+
+ ovl_set_flag(OVL_UPPERDATA, d_inode(c->dentry));
+ return err;
+}
+
static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
{
int err;
@@ -474,8 +506,19 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
return err;
}
+ if (c->metacopy) {
+ err = ovl_check_setxattr(c->dentry, temp, OVL_XATTR_METACOPY,
+ NULL, 0, -EOPNOTSUPP);
+ if (err)
+ return err;
+ }
+
+
inode_lock(temp->d_inode);
- err = ovl_set_attr(temp, &c->stat);
+ if (c->metacopy)
+ err = ovl_set_size(temp, &c->stat);
+ if (!err)
+ err = ovl_set_attr(temp, &c->stat);
inode_unlock(temp->d_inode);
return err;
@@ -506,6 +549,8 @@ static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c)
if (err)
goto out_cleanup;
+ if (!c->metacopy && S_ISREG(d_inode(c->dentry)->i_mode))
+ ovl_set_flag(OVL_UPPERDATA, d_inode(c->dentry));
ovl_inode_update(d_inode(c->dentry), newdentry);
out:
dput(temp);
@@ -632,7 +677,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
}
ovl_do_check_copy_up(ctx.lowerpath.dentry);
- err = ovl_copy_up_start(dentry);
+ err = ovl_copy_up_start(dentry, flags);
/* err < 0: interrupted, err > 0: raced with another copy-up */
if (unlikely(err)) {
if (err > 0)
@@ -642,6 +687,8 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
err = ovl_do_copy_up(&ctx);
if (!err && !ovl_dentry_has_upper_alias(dentry))
err = ovl_link_up(&ctx);
+ if (!err && ovl_dentry_needs_data_copy_up(dentry, flags))
+ err = ovl_copy_up_meta_inode_data(&ctx);
ovl_copy_up_end(dentry);
}
do_delayed_call(&done);
@@ -672,8 +719,10 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags)
* with rename.
*/
if (ovl_dentry_upper(dentry) &&
- ovl_dentry_has_upper_alias(dentry))
+ ovl_dentry_has_upper_alias(dentry) &&
+ !ovl_dentry_needs_data_copy_up(dentry, flags)) {
break;
+ }
next = dget(dentry);
/* find the topmost dentry not yet copied up */
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 321511e..1b4b42c 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -320,7 +320,8 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type)
static bool ovl_open_need_copy_up(struct dentry *dentry, int flags)
{
if (ovl_dentry_upper(dentry) &&
- ovl_dentry_has_upper_alias(dentry))
+ ovl_dentry_has_upper_alias(dentry) &&
+ !ovl_dentry_needs_data_copy_up(dentry, flags))
return false;
if (special_file(d_inode(dentry)->i_mode))
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index d9a0edd..714abf9 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -26,10 +26,12 @@ enum ovl_path_type {
#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
+#define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
enum ovl_flag {
OVL_IMPURE,
OVL_INDEX,
+ OVL_UPPERDATA,
};
/*
@@ -211,6 +213,8 @@ bool ovl_dentry_is_whiteout(struct dentry *dentry);
void ovl_dentry_set_opaque(struct dentry *dentry);
bool ovl_dentry_has_upper_alias(struct dentry *dentry);
void ovl_dentry_set_upper_alias(struct dentry *dentry);
+bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
+bool ovl_dentry_check_upperdata(struct dentry *dentry);
bool ovl_redirect_dir(struct super_block *sb);
const char *ovl_dentry_get_redirect(struct dentry *dentry);
void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
@@ -221,7 +225,7 @@ void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
u64 ovl_dentry_version_get(struct dentry *dentry);
bool ovl_is_whiteout(struct dentry *dentry);
struct file *ovl_path_open(struct path *path, int flags);
-int ovl_copy_up_start(struct dentry *dentry);
+int ovl_copy_up_start(struct dentry *dentry, int flags);
void ovl_copy_up_end(struct dentry *dentry);
bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index a4ce1c9..ef720a9 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -227,6 +227,35 @@ void ovl_dentry_set_upper_alias(struct dentry *dentry)
oe->has_upper = true;
}
+bool ovl_dentry_check_upperdata(struct dentry *dentry) {
+ if (!S_ISREG(d_inode(dentry)->i_mode))
+ return false;
+
+ if (!ovl_dentry_lower(dentry))
+ return false;
+
+ return true;
+}
+
+bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags) {
+ if (!ovl_dentry_check_upperdata(dentry))
+ return false;
+
+ if (!S_ISREG(d_inode(dentry)->i_mode))
+ return false;
+
+ if (!flags)
+ return false;
+
+ if (!(OPEN_FMODE(flags) & FMODE_WRITE))
+ return false;
+
+ if (likely(ovl_test_flag(OVL_UPPERDATA, d_inode(dentry))))
+ return false;
+
+ return true;
+}
+
bool ovl_redirect_dir(struct super_block *sb)
{
struct ovl_fs *ofs = sb->s_fs_info;
@@ -310,13 +339,14 @@ struct file *ovl_path_open(struct path *path, int flags)
return dentry_open(path, flags | O_NOATIME, current_cred());
}
-int ovl_copy_up_start(struct dentry *dentry)
+int ovl_copy_up_start(struct dentry *dentry, int flags)
{
struct ovl_inode *oi = OVL_I(d_inode(dentry));
int err;
err = mutex_lock_interruptible(&oi->lock);
- if (!err && ovl_dentry_has_upper_alias(dentry)) {
+ if (!err && ovl_dentry_has_upper_alias(dentry) &&
+ !ovl_dentry_needs_data_copy_up(dentry, flags)) {
err = 1; /* Already copied up */
mutex_unlock(&oi->lock);
}
--
2.5.5
--
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