tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 *
3 * Copyright (C) 2011 Novell Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 */
9
10#include <linux/kernel.h>
11#include <linux/uuid.h>
12#include <linux/fs.h>
13#include "ovl_entry.h"
14
15enum ovl_path_type {
16 __OVL_PATH_UPPER = (1 << 0),
17 __OVL_PATH_MERGE = (1 << 1),
18 __OVL_PATH_ORIGIN = (1 << 2),
19};
20
21#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
22#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
23#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
24
25#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
26#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
27#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
28#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
29#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
30#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
31#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
32#define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
33
34enum ovl_inode_flag {
35 /* Pure upper dir that may contain non pure upper entries */
36 OVL_IMPURE,
37 /* Non-merge dir that may contain whiteout entries */
38 OVL_WHITEOUTS,
39 OVL_INDEX,
40 OVL_UPPERDATA,
41 /* Inode number will remain constant over copy up. */
42 OVL_CONST_INO,
43};
44
45enum ovl_entry_flag {
46 OVL_E_UPPER_ALIAS,
47 OVL_E_OPAQUE,
48 OVL_E_CONNECTED,
49};
50
51/*
52 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
53 * where:
54 * origin.fh - exported file handle of the lower file
55 * origin.uuid - uuid of the lower filesystem
56 */
57#define OVL_FH_VERSION 0
58#define OVL_FH_MAGIC 0xfb
59
60/* CPU byte order required for fid decoding: */
61#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
62#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
63/* Is the real inode encoded in fid an upper inode? */
64#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
65
66#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
67 OVL_FH_FLAG_PATH_UPPER)
68
69#if defined(__LITTLE_ENDIAN)
70#define OVL_FH_FLAG_CPU_ENDIAN 0
71#elif defined(__BIG_ENDIAN)
72#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
73#else
74#error Endianness not defined
75#endif
76
77/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
78#define OVL_FILEID 0xfb
79
80/* On-disk and in-memeory format for redirect by file handle */
81struct ovl_fh {
82 u8 version; /* 0 */
83 u8 magic; /* 0xfb */
84 u8 len; /* size of this header + size of fid */
85 u8 flags; /* OVL_FH_FLAG_* */
86 u8 type; /* fid_type of fid */
87 uuid_t uuid; /* uuid of filesystem */
88 u8 fid[0]; /* file identifier */
89} __packed;
90
91static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
92{
93 int err = vfs_rmdir(dir, dentry);
94
95 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
96 return err;
97}
98
99static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
100{
101 int err = vfs_unlink(dir, dentry, NULL);
102
103 pr_debug("unlink(%pd2) = %i\n", dentry, err);
104 return err;
105}
106
107static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
108 struct dentry *new_dentry)
109{
110 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
111
112 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
113 return err;
114}
115
116static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
117 umode_t mode)
118{
119 int err = vfs_create(dir, dentry, mode, true);
120
121 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
122 return err;
123}
124
125static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
126 umode_t mode)
127{
128 int err = vfs_mkdir(dir, dentry, mode);
129 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
130 return err;
131}
132
133static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
134 umode_t mode, dev_t dev)
135{
136 int err = vfs_mknod(dir, dentry, mode, dev);
137
138 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
139 return err;
140}
141
142static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
143 const char *oldname)
144{
145 int err = vfs_symlink(dir, dentry, oldname);
146
147 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
148 return err;
149}
150
151static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
152 const void *value, size_t size, int flags)
153{
154 int err = vfs_setxattr(dentry, name, value, size, flags);
155 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
156 dentry, name, (int) size, (char *) value, flags, err);
157 return err;
158}
159
160static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
161{
162 int err = vfs_removexattr(dentry, name);
163 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
164 return err;
165}
166
167static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
168 struct inode *newdir, struct dentry *newdentry,
169 unsigned int flags)
170{
171 int err;
172
173 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
174 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
175 if (err) {
176 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
177 olddentry, newdentry, err);
178 }
179 return err;
180}
181
182static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
183{
184 int err = vfs_whiteout(dir, dentry);
185 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
186 return err;
187}
188
189static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
190{
191 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
192 int err = PTR_ERR_OR_ZERO(ret);
193
194 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
195 return ret;
196}
197
198static inline bool ovl_open_flags_need_copy_up(int flags)
199{
200 if (!flags)
201 return false;
202
203 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
204}
205
206/* util.c */
207int ovl_want_write(struct dentry *dentry);
208void ovl_drop_write(struct dentry *dentry);
209struct dentry *ovl_workdir(struct dentry *dentry);
210const struct cred *ovl_override_creds(struct super_block *sb);
211struct super_block *ovl_same_sb(struct super_block *sb);
212int ovl_can_decode_fh(struct super_block *sb);
213struct dentry *ovl_indexdir(struct super_block *sb);
214bool ovl_index_all(struct super_block *sb);
215bool ovl_verify_lower(struct super_block *sb);
216struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
217bool ovl_dentry_remote(struct dentry *dentry);
218bool ovl_dentry_weird(struct dentry *dentry);
219enum ovl_path_type ovl_path_type(struct dentry *dentry);
220void ovl_path_upper(struct dentry *dentry, struct path *path);
221void ovl_path_lower(struct dentry *dentry, struct path *path);
222void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
223enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
224struct dentry *ovl_dentry_upper(struct dentry *dentry);
225struct dentry *ovl_dentry_lower(struct dentry *dentry);
226struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
227struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
228struct dentry *ovl_dentry_real(struct dentry *dentry);
229struct dentry *ovl_i_dentry_upper(struct inode *inode);
230struct inode *ovl_inode_upper(struct inode *inode);
231struct inode *ovl_inode_lower(struct inode *inode);
232struct inode *ovl_inode_lowerdata(struct inode *inode);
233struct inode *ovl_inode_real(struct inode *inode);
234struct inode *ovl_inode_realdata(struct inode *inode);
235struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
236void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
237void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
238void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
239bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
240bool ovl_dentry_is_opaque(struct dentry *dentry);
241bool ovl_dentry_is_whiteout(struct dentry *dentry);
242void ovl_dentry_set_opaque(struct dentry *dentry);
243bool ovl_dentry_has_upper_alias(struct dentry *dentry);
244void ovl_dentry_set_upper_alias(struct dentry *dentry);
245bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
246bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
247bool ovl_has_upperdata(struct inode *inode);
248void ovl_set_upperdata(struct inode *inode);
249bool ovl_redirect_dir(struct super_block *sb);
250const char *ovl_dentry_get_redirect(struct dentry *dentry);
251void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
252void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
253 struct dentry *lowerdentry, struct dentry *lowerdata);
254void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
255void ovl_dir_modified(struct dentry *dentry, bool impurity);
256u64 ovl_dentry_version_get(struct dentry *dentry);
257bool ovl_is_whiteout(struct dentry *dentry);
258struct file *ovl_path_open(struct path *path, int flags);
259int ovl_copy_up_start(struct dentry *dentry, int flags);
260void ovl_copy_up_end(struct dentry *dentry);
261bool ovl_already_copied_up(struct dentry *dentry, int flags);
262bool ovl_check_origin_xattr(struct dentry *dentry);
263bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
264int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
265 const char *name, const void *value, size_t size,
266 int xerr);
267int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
268void ovl_set_flag(unsigned long flag, struct inode *inode);
269void ovl_clear_flag(unsigned long flag, struct inode *inode);
270bool ovl_test_flag(unsigned long flag, struct inode *inode);
271bool ovl_inuse_trylock(struct dentry *dentry);
272void ovl_inuse_unlock(struct dentry *dentry);
273bool ovl_need_index(struct dentry *dentry);
274int ovl_nlink_start(struct dentry *dentry, bool *locked);
275void ovl_nlink_end(struct dentry *dentry, bool locked);
276int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
277int ovl_check_metacopy_xattr(struct dentry *dentry);
278bool ovl_is_metacopy_dentry(struct dentry *dentry);
279char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
280
281static inline bool ovl_is_impuredir(struct dentry *dentry)
282{
283 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
284}
285
286static inline unsigned int ovl_xino_bits(struct super_block *sb)
287{
288 struct ovl_fs *ofs = sb->s_fs_info;
289
290 return ofs->xino_bits;
291}
292
293
294/* namei.c */
295int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
296struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
297 bool connected);
298int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
299 struct dentry *upperdentry, struct ovl_path **stackp);
300int ovl_verify_set_fh(struct dentry *dentry, const char *name,
301 struct dentry *real, bool is_upper, bool set);
302struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
303int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
304int ovl_get_index_name(struct dentry *origin, struct qstr *name);
305struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
306struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
307 struct dentry *origin, bool verify);
308int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
309struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
310 unsigned int flags);
311bool ovl_lower_positive(struct dentry *dentry);
312
313static inline int ovl_verify_origin(struct dentry *upper,
314 struct dentry *origin, bool set)
315{
316 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
317}
318
319static inline int ovl_verify_upper(struct dentry *index,
320 struct dentry *upper, bool set)
321{
322 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
323}
324
325/* readdir.c */
326extern const struct file_operations ovl_dir_operations;
327int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
328void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
329void ovl_cache_free(struct list_head *list);
330void ovl_dir_cache_free(struct inode *inode);
331int ovl_check_d_type_supported(struct path *realpath);
332void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
333 struct dentry *dentry, int level);
334int ovl_indexdir_cleanup(struct ovl_fs *ofs);
335
336/* inode.c */
337int ovl_set_nlink_upper(struct dentry *dentry);
338int ovl_set_nlink_lower(struct dentry *dentry);
339unsigned int ovl_get_nlink(struct dentry *lowerdentry,
340 struct dentry *upperdentry,
341 unsigned int fallback);
342int ovl_setattr(struct dentry *dentry, struct iattr *attr);
343int ovl_getattr(const struct path *path, struct kstat *stat,
344 u32 request_mask, unsigned int flags);
345int ovl_permission(struct inode *inode, int mask);
346int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
347 const void *value, size_t size, int flags);
348int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
349 void *value, size_t size);
350ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
351struct posix_acl *ovl_get_acl(struct inode *inode, int type);
352int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
353bool ovl_is_private_xattr(const char *name);
354
355struct ovl_inode_params {
356 struct inode *newinode;
357 struct dentry *upperdentry;
358 struct ovl_path *lowerpath;
359 struct dentry *index;
360 unsigned int numlower;
361 char *redirect;
362 struct dentry *lowerdata;
363};
364struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
365struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
366 bool is_upper);
367struct inode *ovl_get_inode(struct super_block *sb,
368 struct ovl_inode_params *oip);
369static inline void ovl_copyattr(struct inode *from, struct inode *to)
370{
371 to->i_uid = from->i_uid;
372 to->i_gid = from->i_gid;
373 to->i_mode = from->i_mode;
374 to->i_atime = from->i_atime;
375 to->i_mtime = from->i_mtime;
376 to->i_ctime = from->i_ctime;
377 i_size_write(to, i_size_read(from));
378}
379
380static inline void ovl_copyflags(struct inode *from, struct inode *to)
381{
382 unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
383
384 inode_set_flags(to, from->i_flags & mask, mask);
385}
386
387/* dir.c */
388extern const struct inode_operations ovl_dir_inode_operations;
389int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
390 struct dentry *dentry);
391struct ovl_cattr {
392 dev_t rdev;
393 umode_t mode;
394 const char *link;
395 struct dentry *hardlink;
396};
397
398#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
399
400struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
401 struct ovl_cattr *attr);
402int ovl_cleanup(struct inode *dir, struct dentry *dentry);
403struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
404
405/* file.c */
406extern const struct file_operations ovl_file_operations;
407
408/* copy_up.c */
409int ovl_copy_up(struct dentry *dentry);
410int ovl_copy_up_with_data(struct dentry *dentry);
411int ovl_copy_up_flags(struct dentry *dentry, int flags);
412int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
413int ovl_copy_xattr(struct dentry *old, struct dentry *new);
414int ovl_set_attr(struct dentry *upper, struct kstat *stat);
415struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
416int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
417 struct dentry *upper);
418
419/* export.c */
420extern const struct export_operations ovl_export_operations;