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| author |   Miklos Szeredi <mszeredi@redhat.com> | 2016-07-29 12:05:24 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2016-07-29 12:05:24 +0200 |
| commit | 39b681f8026c170a73972517269efc830db0d7ce (patch) | |
| tree | 592a1c87e7b3f16d5422577ee9aa9bd6e93f49e9 /fs/overlayfs/overlayfs.h | |
| parent | ovl: permission: return ECHILD instead of ENOENT (diff) | |
| download | linux-dev-39b681f8026c170a73972517269efc830db0d7ce.tar.xz linux-dev-39b681f8026c170a73972517269efc830db0d7ce.zip | |
ovl: store real inode pointer in ->i_private
To get from overlay inode to real inode we currently use 'struct
ovl_entry', which has lifetime connected to overlay dentry. This is okay,
since each overlay dentry had a new overlay inode allocated.
Following patch will break that assumption, so need to leave out ovl_entry.
This patch stores the real inode directly in i_private, with the lowest bit
used to indicate whether the inode is upper or lower.
Lifetime rules remain, using ovl_inode_real() must only be done while
caller holds ref on overlay dentry (and hence on real dentry), or within
RCU protected regions.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index fb73c09a84e7..6410209ea616 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -27,6 +27,8 @@ enum ovl_path_type { #define OVL_XATTR_PRE_LEN 16 #define OVL_XATTR_OPAQUE OVL_XATTR_PRE_NAME"opaque" +#define OVL_ISUPPER_MASK 1UL + static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry) { int err = vfs_rmdir(dir, dentry); @@ -131,6 +133,16 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) return err; } +static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) +{ + unsigned long x = (unsigned long) READ_ONCE(inode->i_private); + + if (is_upper) + *is_upper = x & OVL_ISUPPER_MASK; + + return (struct inode *) (x & ~OVL_ISUPPER_MASK); +} + enum ovl_path_type ovl_path_type(struct dentry *dentry); u64 ovl_dentry_version_get(struct dentry *dentry); void ovl_dentry_version_inc(struct dentry *dentry); @@ -141,8 +153,6 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); -struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper); -struct inode *ovl_inode_real(struct inode *inode); struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode, bool is_upper); struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); @@ -155,6 +165,7 @@ void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque); bool ovl_is_whiteout(struct dentry *dentry); const struct cred *ovl_override_creds(struct super_block *sb); void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry); +void ovl_inode_update(struct inode *inode, struct inode *upperinode); struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); struct file *ovl_path_open(struct path *path, int flags); @@ -183,8 +194,7 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type); int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags); int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); -struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, - struct ovl_entry *oe); +struct inode *ovl_new_inode(struct super_block *sb, umode_t mode); static inline void ovl_copyattr(struct inode *from, struct inode *to) { to->i_uid = from->i_uid; |