Store upper layer's ovl_layer structure and root upper dentry into
ovl_fs sturcture for the upcoming "feature set" feature. "feature set"
feature will read upper layer's feature from upper root dentry and save
feature bit mask into upper layer's ovl_layer structure.
This patch relpace ->upper_mnt to ->upper_layer and add a helper func
ovl_upper_mnt() to get ->upper_mnt easily.
Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
---
fs/overlayfs/export.c | 12 +++++-------
fs/overlayfs/inode.c | 4 ++--
fs/overlayfs/namei.c | 2 +-
fs/overlayfs/ovl_entry.h | 9 ++++++++-
fs/overlayfs/readdir.c | 2 +-
fs/overlayfs/super.c | 39 ++++++++++++++++++++++++---------------
fs/overlayfs/util.c | 10 +++++-----
7 files changed, 46 insertions(+), 32 deletions(-)
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 9941ece61a14..0a11bd46895a 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -207,7 +207,7 @@ static int ovl_check_encode_origin(struct dentry *dentry)
* ovl_connect_layer() will try to make origin's layer "connected" by
* copying up a "connectable" ancestor.
*/
- if (d_is_dir(dentry) && ofs->upper_mnt)
+ if (d_is_dir(dentry) && ofs->upper_layer)
return ovl_connect_layer(dentry);
/* Lower file handle for indexed and non-upper dir/non-dir */
@@ -434,7 +434,6 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
struct ovl_layer *layer)
{
struct ovl_fs *ofs = sb->s_fs_info;
- struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt };
struct dentry *index = NULL;
struct dentry *this = NULL;
struct inode *inode;
@@ -476,7 +475,7 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
* recursive call walks back from indexed upper to the topmost
* connected/hashed upper parent (or up to root).
*/
- this = ovl_lookup_real(sb, upper, &upper_layer);
+ this = ovl_lookup_real(sb, upper, ofs->upper_layer);
dput(upper);
}
@@ -656,8 +655,7 @@ static struct dentry *ovl_get_dentry(struct super_block *sb,
struct dentry *index)
{
struct ovl_fs *ofs = sb->s_fs_info;
- struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt };
- struct ovl_layer *layer = upper ? &upper_layer : lowerpath->layer;
+ struct ovl_layer *layer = upper ? ofs->upper_layer : lowerpath->layer;
struct dentry *real = upper ?: (index ?: lowerpath->dentry);
/*
@@ -685,10 +683,10 @@ static struct dentry *ovl_upper_fh_to_d(struct super_block *sb,
struct dentry *dentry;
struct dentry *upper;
- if (!ofs->upper_mnt)
+ if (!ofs->upper_layer)
return ERR_PTR(-EACCES);
- upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
+ upper = ovl_decode_real_fh(fh, ovl_upper_mnt(ofs), true);
if (IS_ERR_OR_NULL(upper))
return upper;
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index ed16a898caeb..0b6ecf26c066 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -421,7 +421,7 @@ int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags)
if (flags & S_ATIME) {
struct ovl_fs *ofs = inode->i_sb->s_fs_info;
struct path upperpath = {
- .mnt = ofs->upper_mnt,
+ .mnt = ovl_upper_mnt(ofs),
.dentry = ovl_upperdentry_dereference(OVL_I(inode)),
};
@@ -733,7 +733,7 @@ static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
return true;
/* Yes, if won't be copied up */
- if (!ofs->upper_mnt)
+ if (!ofs->upper_layer)
return true;
/* No, if lower hardlink is or will be broken on copy up */
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index c993dd8db739..bb2d347c0a7e 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -475,7 +475,7 @@ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
if (IS_ERR_OR_NULL(fh))
return ERR_CAST(fh);
- upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
+ upper = ovl_decode_real_fh(fh, ovl_upper_mnt(ofs), true);
kfree(fh);
if (IS_ERR_OR_NULL(upper))
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 41655a7d6894..38ff6689a293 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -28,6 +28,7 @@ struct ovl_sb {
struct ovl_layer {
struct vfsmount *mnt;
+ /* Private fs info of this layer (upper fs == NULL) */
struct ovl_sb *fs;
/* Index of this layer in fs root (upper idx == 0) */
int idx;
@@ -42,7 +43,8 @@ struct ovl_path {
/* private information held for overlayfs's superblock */
struct ovl_fs {
- struct vfsmount *upper_mnt;
+ struct ovl_layer *upper_layer;
+ struct dentry *upperdir;
unsigned int numlower;
/* Number of unique lower sb that differ from upper sb */
unsigned int numlowerfs;
@@ -109,3 +111,8 @@ static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi)
{
return READ_ONCE(oi->__upperdentry);
}
+
+static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs)
+{
+ return ofs->upper_layer ? ofs->upper_layer->mnt : NULL;
+}
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index ef1fe42ff7bb..1b70ffe4a633 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -1069,7 +1069,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
struct dentry *indexdir = ofs->indexdir;
struct dentry *index = NULL;
struct inode *dir = indexdir->d_inode;
- struct path path = { .mnt = ofs->upper_mnt, .dentry = indexdir };
+ struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = indexdir };
LIST_HEAD(list);
struct rb_root root = RB_ROOT;
struct ovl_cache_entry *p;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 704b37311467..cce4f58458dc 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -240,8 +240,10 @@ static void ovl_free_fs(struct ovl_fs *ofs)
ovl_inuse_unlock(ofs->workbasedir);
dput(ofs->workbasedir);
if (ofs->upperdir_locked)
- ovl_inuse_unlock(ofs->upper_mnt->mnt_root);
- mntput(ofs->upper_mnt);
+ ovl_inuse_unlock(ovl_upper_mnt(ofs)->mnt_root);
+ dput(ofs->upperdir);
+ mntput(ovl_upper_mnt(ofs));
+ kfree(ofs->upper_layer);
for (i = 0; i < ofs->numlower; i++)
mntput(ofs->lower_layers[i].mnt);
for (i = 0; i < ofs->numlowerfs; i++)
@@ -272,7 +274,7 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
struct super_block *upper_sb;
int ret;
- if (!ofs->upper_mnt)
+ if (!ofs->upper_layer)
return 0;
/*
@@ -286,7 +288,7 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
if (!wait)
return 0;
- upper_sb = ofs->upper_mnt->mnt_sb;
+ upper_sb = ovl_upper_mnt(ofs)->mnt_sb;
down_read(&upper_sb->s_umount);
ret = sync_filesystem(upper_sb);
@@ -324,7 +326,7 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
/* Will this overlay be forced to mount/remount ro? */
static bool ovl_force_readonly(struct ovl_fs *ofs)
{
- return (!ofs->upper_mnt || !ofs->workdir);
+ return (!ofs->upper_layer || !ofs->workdir);
}
static const char *ovl_redirect_mode_def(void)
@@ -579,7 +581,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
const char *name, bool persist)
{
struct inode *dir = ofs->workbasedir->d_inode;
- struct vfsmount *mnt = ofs->upper_mnt;
+ struct vfsmount *mnt = ovl_upper_mnt(ofs);
struct dentry *work;
int err;
bool retried = false;
@@ -989,7 +991,14 @@ static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
/* Don't inherit atime flags */
upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME);
- ofs->upper_mnt = upper_mnt;
+
+ err = -ENOMEM;
+ ofs->upper_layer = kzalloc(sizeof(struct ovl_layer), GFP_KERNEL);
+ if (ofs->upper_layer == NULL)
+ goto out;
+
+ ofs->upper_layer->mnt = upper_mnt;
+ ofs->upperdir = dget(upperpath->dentry);
err = 0;
out:
return err;
@@ -997,7 +1006,7 @@ static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
{
- struct vfsmount *mnt = ofs->upper_mnt;
+ struct vfsmount *mnt = ovl_upper_mnt(ofs);
struct dentry *temp;
int fh_type;
int err;
@@ -1114,7 +1123,7 @@ static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe,
struct path *upperpath)
{
- struct vfsmount *mnt = ofs->upper_mnt;
+ struct vfsmount *mnt = ovl_upper_mnt(ofs);
int err;
err = mnt_want_write(mnt);
@@ -1169,7 +1178,7 @@ static int ovl_get_fsid(struct ovl_fs *ofs, struct super_block *sb)
int err;
/* fsid 0 is reserved for upper fs even with non upper overlay */
- if (ofs->upper_mnt && ofs->upper_mnt->mnt_sb == sb)
+ if (ofs->upper_layer && ovl_upper_mnt(ofs)->mnt_sb == sb)
return 0;
for (i = 0; i < ofs->numlowerfs; i++) {
@@ -1246,7 +1255,7 @@ static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack,
* bits reserved for fsid, it emits a warning and uses the original
* inode number.
*/
- if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_mnt)) {
+ if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_layer)) {
ofs->xino_bits = 0;
ofs->config.xino = OVL_XINO_OFF;
} else if (ofs->config.xino == OVL_XINO_ON && !ofs->xino_bits) {
@@ -1409,8 +1418,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!ofs->workdir)
sb->s_flags |= SB_RDONLY;
- sb->s_stack_depth = ofs->upper_mnt->mnt_sb->s_stack_depth;
- sb->s_time_gran = ofs->upper_mnt->mnt_sb->s_time_gran;
+ sb->s_stack_depth = ovl_upper_mnt(ofs)->mnt_sb->s_stack_depth;
+ sb->s_time_gran = ovl_upper_mnt(ofs)->mnt_sb->s_time_gran;
}
oe = ovl_get_lowerstack(sb, ofs);
@@ -1419,7 +1428,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
goto out_err;
/* If the upper fs is nonexistent, we mark overlayfs r/o too */
- if (!ofs->upper_mnt)
+ if (!ofs->upper_layer)
sb->s_flags |= SB_RDONLY;
if (!(ovl_force_readonly(ofs)) && ofs->config.index) {
@@ -1439,7 +1448,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
/* Show index=off in /proc/mounts for forced r/o mount */
if (!ofs->indexdir) {
ofs->config.index = false;
- if (ofs->upper_mnt && ofs->config.nfs_export) {
+ if (ofs->upper_layer && ofs->config.nfs_export) {
pr_warn("overlayfs: NFS export requires an index dir, falling back to nfs_export=off.\n");
ofs->config.nfs_export = false;
}
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 6f1078028c66..6499f3b6fc5a 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -21,13 +21,13 @@
int ovl_want_write(struct dentry *dentry)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- return mnt_want_write(ofs->upper_mnt);
+ return mnt_want_write(ovl_upper_mnt(ofs));
}
void ovl_drop_write(struct dentry *dentry)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- mnt_drop_write(ofs->upper_mnt);
+ mnt_drop_write(ovl_upper_mnt(ofs));
}
struct dentry *ovl_workdir(struct dentry *dentry)
@@ -48,8 +48,8 @@ struct super_block *ovl_same_sb(struct super_block *sb)
struct ovl_fs *ofs = sb->s_fs_info;
if (!ofs->numlowerfs)
- return ofs->upper_mnt->mnt_sb;
- else if (ofs->numlowerfs == 1 && !ofs->upper_mnt)
+ return ovl_upper_mnt(ofs)->mnt_sb;
+ else if (ofs->numlowerfs == 1 && !ofs->upper_layer)
return ofs->lower_fs[0].sb;
else
return NULL;
@@ -148,7 +148,7 @@ void ovl_path_upper(struct dentry *dentry, struct path *path)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- path->mnt = ofs->upper_mnt;
+ path->mnt = ovl_upper_mnt(ofs);
path->dentry = ovl_dentry_upper(dentry);
}
--
2.13.6
--
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