AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-26 18:05:19 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
a466856e0b
linux_dsm_epyc7002/fs/overlayfs/overlayfs.h
Amir Goldstein 2ca3c148a0 ovl: check lower ancestry on encode of lower dir file handle 
This change relaxes copy up on encode of merge dir with lower layer > 1
and handles the case of encoding a merge dir with lower layer 1, where an
ancestor is a non-indexed merge dir. In that case, decode of the lower
file handle will not have been possible if the non-indexed ancestor is
redirected before or after encode.

Before encoding a non-upper directory file handle from real layer N, we
need to check if it will be possible to reconnect an overlay dentry from
the real lower decoded dentry. This is done by following the overlay
ancestry up to a "layer N connected" ancestor and verifying that all
parents along the way are "layer N connectable". If an ancestor that is
NOT "layer N connectable" is found, we need to copy up an ancestor, which
is "layer N connectable", thus making that ancestor "layer N connected".
For example:

 layer 1: /a
 layer 2: /a/b/c

The overlay dentry /a is NOT "layer 2 connectable", because if dir /a is
copied up and renamed, upper dir /a will be indexed by lower dir /a from
layer 1. The dir /a from layer 2 will never be indexed, so the algorithm
in ovl_lookup_real_ancestor() (*) will not be able to lookup a connected
overlay dentry from the connected lower dentry /a/b/c.

To avoid this problem on decode time, we need to copy up an ancestor of
/a/b/c, which is "layer 2 connectable", on encode time. That ancestor is
/a/b. After copy up (and index) of /a/b, it will become "layer 2 connected"
and when the time comes to decode the file handle from lower dentry /a/b/c,
ovl_lookup_real_ancestor() will find the indexed ancestor /a/b and decoding
a connected overlay dentry will be accomplished.

(*) the algorithm in ovl_lookup_real_ancestor() can be improved to lookup
an entry /a in the lower layers above layer N and find the indexed dir /a
from layer 1. If that improvement is made, then the check for "layer N
connected" will need to verify there are no redirects in lower layers above
layer N. In the example above, /a will be "layer 2 connectable". However,
if layer 2 dir /a is a target of a layer 1 redirect, then /a will NOT be
"layer 2 connectable":

 layer 1: /A (redirect = /a)
 layer 2: /a/b/c

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-02-16 15:53:20 +01:00

370 lines
13 KiB
C
Raw Blame History

/*
*
* Copyright (C) 2011 Novell Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/uuid.h>
#include "ovl_entry.h"
enum ovl_path_type {
__OVL_PATH_UPPER = (1 << 0),
__OVL_PATH_MERGE = (1 << 1),
__OVL_PATH_ORIGIN = (1 << 2),
};
#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
#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_UPPER OVL_XATTR_PREFIX "upper"
enum ovl_inode_flag {
/* Pure upper dir that may contain non pure upper entries */
OVL_IMPURE,
/* Non-merge dir that may contain whiteout entries */
OVL_WHITEOUTS,
OVL_INDEX,
};
enum ovl_entry_flag {
OVL_E_UPPER_ALIAS,
OVL_E_OPAQUE,
OVL_E_CONNECTED,
};
/*
* The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
* where:
* origin.fh - exported file handle of the lower file
* origin.uuid - uuid of the lower filesystem
*/
#define OVL_FH_VERSION 0
#define OVL_FH_MAGIC 0xfb
/* CPU byte order required for fid decoding: */
#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
/* Is the real inode encoded in fid an upper inode? */
#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
OVL_FH_FLAG_PATH_UPPER)
#if defined(__LITTLE_ENDIAN)
#define OVL_FH_FLAG_CPU_ENDIAN 0
#elif defined(__BIG_ENDIAN)
#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
#else
#error Endianness not defined
#endif
/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
#define OVL_FILEID 0xfb
/* On-disk and in-memeory format for redirect by file handle */
struct ovl_fh {
u8 version; /* 0 */
u8 magic; /* 0xfb */
u8 len; /* size of this header + size of fid */
u8 flags; /* OVL_FH_FLAG_* */
u8 type; /* fid_type of fid */
uuid_t uuid; /* uuid of filesystem */
u8 fid[0]; /* file identifier */
} __packed;
static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = vfs_rmdir(dir, dentry);
pr_debug("rmdir(%pd2) = %i\n", dentry, err);
return err;
}
static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
{
int err = vfs_unlink(dir, dentry, NULL);
pr_debug("unlink(%pd2) = %i\n", dentry, err);
return err;
}
static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry, bool debug)
{
int err = vfs_link(old_dentry, dir, new_dentry, NULL);
if (debug) {
pr_debug("link(%pd2, %pd2) = %i\n",
old_dentry, new_dentry, err);
}
return err;
}
static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool debug)
{
int err = vfs_create(dir, dentry, mode, true);
if (debug)
pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
return err;
}
static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
umode_t mode, bool debug)
{
int err = vfs_mkdir(dir, dentry, mode);
if (debug)
pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
return err;
}
static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t dev, bool debug)
{
int err = vfs_mknod(dir, dentry, mode, dev);
if (debug) {
pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
dentry, mode, dev, err);
}
return err;
}
static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
const char *oldname, bool debug)
{
int err = vfs_symlink(dir, dentry, oldname);
if (debug)
pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
return err;
}
static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
int err = vfs_setxattr(dentry, name, value, size, flags);
pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
dentry, name, (int) size, (char *) value, flags, err);
return err;
}
static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
{
int err = vfs_removexattr(dentry, name);
pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
return err;
}
static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
struct inode *newdir, struct dentry *newdentry,
unsigned int flags)
{
int err;
pr_debug("rename(%pd2, %pd2, 0x%x)\n",
olddentry, newdentry, flags);
err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
if (err) {
pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
olddentry, newdentry, err);
}
return err;
}
static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
{
int err = vfs_whiteout(dir, dentry);
pr_debug("whiteout(%pd2) = %i\n", dentry, err);
return err;
}
static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
{
struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
int err = PTR_ERR_OR_ZERO(ret);
pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
return ret;
}
/* util.c */
int ovl_want_write(struct dentry *dentry);
void ovl_drop_write(struct dentry *dentry);
struct dentry *ovl_workdir(struct dentry *dentry);
const struct cred *ovl_override_creds(struct super_block *sb);
struct super_block *ovl_same_sb(struct super_block *sb);
bool ovl_can_decode_fh(struct super_block *sb);
struct dentry *ovl_indexdir(struct super_block *sb);
bool ovl_index_all(struct super_block *sb);
bool ovl_verify_lower(struct super_block *sb);
struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
bool ovl_dentry_remote(struct dentry *dentry);
bool ovl_dentry_weird(struct dentry *dentry);
enum ovl_path_type ovl_path_type(struct dentry *dentry);
void ovl_path_upper(struct dentry *dentry, struct path *path);
void ovl_path_lower(struct dentry *dentry, struct path *path);
enum ovl_path_type ovl_path_real(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_i_dentry_upper(struct inode *inode);
struct inode *ovl_inode_upper(struct inode *inode);
struct inode *ovl_inode_lower(struct inode *inode);
struct inode *ovl_inode_real(struct inode *inode);
struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
bool ovl_dentry_is_opaque(struct dentry *dentry);
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_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);
void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
struct dentry *lowerdentry);
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
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);
void ovl_copy_up_end(struct dentry *dentry);
bool ovl_check_origin_xattr(struct dentry *dentry);
bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
const char *name, const void *value, size_t size,
int xerr);
int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
void ovl_set_flag(unsigned long flag, struct inode *inode);
void ovl_clear_flag(unsigned long flag, struct inode *inode);
bool ovl_test_flag(unsigned long flag, struct inode *inode);
bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
bool ovl_need_index(struct dentry *dentry);
int ovl_nlink_start(struct dentry *dentry, bool *locked);
void ovl_nlink_end(struct dentry *dentry, bool locked);
int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
static inline bool ovl_is_impuredir(struct dentry *dentry)
{
return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
}
/* namei.c */
int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt);
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
struct dentry *upperdentry, struct ovl_path **stackp);
int ovl_verify_set_fh(struct dentry *dentry, const char *name,
struct dentry *real, bool is_upper, bool set);
struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
int ovl_get_index_name(struct dentry *origin, struct qstr *name);
struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
struct dentry *origin, bool verify);
int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
bool ovl_lower_positive(struct dentry *dentry);
static inline int ovl_verify_origin(struct dentry *upper,
struct dentry *origin, bool set)
{
return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
}
static inline int ovl_verify_upper(struct dentry *index,
struct dentry *upper, bool set)
{
return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
}
/* readdir.c */
extern const struct file_operations ovl_dir_operations;
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
void ovl_cache_free(struct list_head *list);
void ovl_dir_cache_free(struct inode *inode);
int ovl_check_d_type_supported(struct path *realpath);
void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
struct dentry *dentry, int level);
int ovl_indexdir_cleanup(struct ovl_fs *ofs);
/* inode.c */
int ovl_set_nlink_upper(struct dentry *dentry);
int ovl_set_nlink_lower(struct dentry *dentry);
unsigned int ovl_get_nlink(struct dentry *lowerdentry,
struct dentry *upperdentry,
unsigned int fallback);
int ovl_setattr(struct dentry *dentry, struct iattr *attr);
int ovl_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags);
int ovl_permission(struct inode *inode, int mask);
int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
const void *value, size_t size, int flags);
int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
void *value, size_t size);
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
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);
bool ovl_is_private_xattr(const char *name);
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,
unsigned int numlower);
static inline void ovl_copyattr(struct inode *from, struct inode *to)
{
to->i_uid = from->i_uid;
to->i_gid = from->i_gid;
to->i_mode = from->i_mode;
to->i_atime = from->i_atime;
to->i_mtime = from->i_mtime;
to->i_ctime = from->i_ctime;
}
/* dir.c */
extern const struct inode_operations ovl_dir_inode_operations;
struct dentry *ovl_lookup_temp(struct dentry *workdir);
int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
struct dentry *dentry);
struct cattr {
dev_t rdev;
umode_t mode;
const char *link;
};
int ovl_create_real(struct inode *dir, struct dentry *newdentry,
struct cattr *attr,
struct dentry *hardlink, bool debug);
int ovl_cleanup(struct inode *dir, struct dentry *dentry);
/* copy_up.c */
int ovl_copy_up(struct dentry *dentry);
int ovl_copy_up_flags(struct dentry *dentry, int flags);
int ovl_copy_xattr(struct dentry *old, struct dentry *new);
int ovl_set_attr(struct dentry *upper, struct kstat *stat);
struct ovl_fh *ovl_encode_fh(struct dentry *real, bool is_upper);
int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
struct dentry *upper);
/* export.c */
extern const struct export_operations ovl_export_operations;
Reference in New Issue View Git Blame Copy Permalink