When overlay layers are not all on the same fs, but all inode numbers
of underlying fs do not use the high 'xino' bits, overlay st_ino values
are constant and persistent.
In that case, set i_ino value to the same value as st_ino for nfsd
readdirplus validator.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/overlayfs/export.c | 2 +-
fs/overlayfs/inode.c | 27 ++++++++++++++++++---------
fs/overlayfs/namei.c | 4 +---
fs/overlayfs/overlayfs.h | 2 +-
4 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 87bd4148f4fb..e53c1f58aef1 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -305,7 +305,7 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb,
if (d_is_dir(upper ?: lower))
return ERR_PTR(-EIO);
- inode = ovl_get_inode(sb, dget(upper), lower, index, !!lower);
+ inode = ovl_get_inode(sb, dget(upper), lowerpath, index, !!lower);
if (IS_ERR(inode)) {
dput(upper);
return ERR_CAST(inode);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 7fc9c83bf2ff..71bf6650b284 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -493,19 +493,26 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode)
}
static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
- unsigned long ino)
+ unsigned long ino, int fsid)
{
+ int xinobits = ovl_xino_bits(inode->i_sb);
+
/*
* When NFS export is enabled and d_ino is consistent with st_ino
- * (samefs), set the same value to i_ino, because nfsd readdirplus
- * compares d_ino values to i_ino values of child entries. When called
- * from ovl_new_inode(), ino arg is 0, so i_ino will be updated to real
+ * (samefs or i_ino has enough bits to encode layer), set the same
+ * value used for d_ino to i_ino, because nfsd readdirplus compares
+ * d_ino values to i_ino values of child entries. When called from
+ * ovl_new_inode(), ino arg is 0, so i_ino will be updated to real
* upper inode i_ino on ovl_inode_init() or ovl_inode_update().
*/
- if (inode->i_sb->s_export_op && ovl_same_sb(inode->i_sb))
+ if (inode->i_sb->s_export_op &&
+ (ovl_same_sb(inode->i_sb) || xinobits)) {
inode->i_ino = ino;
- else
+ if (xinobits && fsid && !(ino >> (64 - xinobits)))
+ inode->i_ino |= (unsigned long)fsid << (64 - xinobits);
+ } else {
inode->i_ino = get_next_ino();
+ }
inode->i_mode = mode;
inode->i_flags |= S_NOCMTIME;
#ifdef CONFIG_FS_POSIX_ACL
@@ -641,7 +648,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev)
inode = new_inode(sb);
if (inode)
- ovl_fill_inode(inode, mode, rdev, 0);
+ ovl_fill_inode(inode, mode, rdev, 0, 0);
return inode;
}
@@ -747,12 +754,14 @@ static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
}
struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
- struct dentry *lowerdentry, struct dentry *index,
+ struct ovl_path *lowerpath, struct dentry *index,
unsigned int numlower)
{
struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
struct inode *inode;
+ struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry, index);
+ int fsid = bylower ? lowerpath->layer->fsid : 0;
bool is_dir;
unsigned long ino = 0;
@@ -800,7 +809,7 @@ struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
if (!inode)
goto out_nomem;
}
- ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino);
+ ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
ovl_inode_init(inode, upperdentry, lowerdentry);
if (upperdentry && ovl_is_impuredir(upperdentry))
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 87d8bf2c09c6..d33f6213eb8f 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -986,9 +986,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
upperdentry = dget(index);
if (upperdentry || ctr) {
- if (ctr)
- origin = stack[0].dentry;
- inode = ovl_get_inode(dentry->d_sb, upperdentry, origin, index,
+ inode = ovl_get_inode(dentry->d_sb, upperdentry, stack, index,
ctr);
err = PTR_ERR(inode);
if (IS_ERR(inode))
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 09f5b8ce70aa..023e35ca6b5f 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -331,7 +331,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
bool is_upper);
struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
- struct dentry *lowerdentry, struct dentry *index,
+ struct ovl_path *lowerpath, struct dentry *index,
unsigned int numlower);
static inline void ovl_copyattr(struct inode *from, struct inode *to)
{
--
2.7.4
--
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