1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (c) 2024 Paulo Alcantara <pc@manguebit.com>
4 */
5
6 #ifndef _CIFS_REPARSE_H
7 #define _CIFS_REPARSE_H
8
9 #include <linux/fs.h>
10 #include <linux/stat.h>
11 #include <linux/uidgid.h>
12 #include "fs_context.h"
13 #include "cifsglob.h"
14
15 /*
16 * Used only by cifs.ko to ignore reparse points from files when client or
17 * server doesn't support FSCTL_GET_REPARSE_POINT.
18 */
19 #define IO_REPARSE_TAG_INTERNAL ((__u32)~0U)
20
21 static inline dev_t reparse_nfs_mkdev(struct reparse_posix_data *buf)
22 {
23 u64 v = le64_to_cpu(*(__le64 *)buf->DataBuffer);
24
25 return MKDEV(v >> 32, v & 0xffffffff);
26 }
27
28 static inline dev_t wsl_mkdev(void *ptr)
29 {
30 u64 v = le64_to_cpu(*(__le64 *)ptr);
31
32 return MKDEV(v & 0xffffffff, v >> 32);
33 }
34
35 static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb,
36 void *ptr)
37 {
38 u32 uid = le32_to_cpu(*(__le32 *)ptr);
39
40 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
41 return cifs_sb->ctx->linux_uid;
42 return make_kuid(current_user_ns(), uid);
43 }
44
45 static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
46 void *ptr)
47 {
48 u32 gid = le32_to_cpu(*(__le32 *)ptr);
49
50 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
51 return cifs_sb->ctx->linux_gid;
52 return make_kgid(current_user_ns(), gid);
53 }
54
55 static inline u64 reparse_mode_nfs_type(mode_t mode)
56 {
57 switch (mode & S_IFMT) {
58 case S_IFBLK: return NFS_SPECFILE_BLK;
59 case S_IFCHR: return NFS_SPECFILE_CHR;
60 case S_IFIFO: return NFS_SPECFILE_FIFO;
61 case S_IFSOCK: return NFS_SPECFILE_SOCK;
62 }
63 return 0;
64 }
65
66 static inline u32 reparse_mode_wsl_tag(mode_t mode)
67 {
68 switch (mode & S_IFMT) {
69 case S_IFBLK: return IO_REPARSE_TAG_LX_BLK;
70 case S_IFCHR: return IO_REPARSE_TAG_LX_CHR;
71 case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO;
72 case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX;
73 }
74 return 0;
75 }
76
77 /*
78 * Match a reparse point inode if reparse tag and ctime haven't changed.
79 *
80 * Windows Server updates ctime of reparse points when their data have changed.
81 * The server doesn't allow changing reparse tags from existing reparse points,
82 * though it's worth checking.
83 */
84 static inline bool reparse_inode_match(struct inode *inode,
85 struct cifs_fattr *fattr)
86 {
87 struct cifsInodeInfo *cinode = CIFS_I(inode);
88 struct timespec64 ctime = inode_get_ctime(inode);
89
90 /*
91 * Do not match reparse tags when client or server doesn't support
92 * FSCTL_GET_REPARSE_POINT. @fattr->cf_cifstag should contain correct
93 * reparse tag from query dir response but the client won't be able to
94 * read the reparse point data anyway. This spares us a revalidation.
95 */
96 if (cinode->reparse_tag != IO_REPARSE_TAG_INTERNAL &&
97 cinode->reparse_tag != fattr->cf_cifstag)
98 return false;
99 return (cinode->cifsAttrs & ATTR_REPARSE) &&
100 timespec64_equal(&ctime, &fattr->cf_ctime);
101 }
102
103 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data)
104 {
105 struct smb2_file_all_info *fi = &data->fi;
106 u32 attrs = le32_to_cpu(fi->Attributes);
107 bool ret;
108
109 ret = data->reparse_point || (attrs & ATTR_REPARSE);
110 if (ret)
111 attrs |= ATTR_REPARSE;
112 fi->Attributes = cpu_to_le32(attrs);
113 return ret;
114 }
115
116 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
117 struct cifs_fattr *fattr,
118 struct cifs_open_info_data *data);
119 int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
120 struct dentry *dentry, struct cifs_tcon *tcon,
121 const char *full_path, const char *symname);
122 int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
123 struct dentry *dentry, struct cifs_tcon *tcon,
124 const char *full_path, umode_t mode, dev_t dev);
125 int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb, struct kvec *rsp_iov,
126 struct cifs_open_info_data *data);
127
128 #endif /* _CIFS_REPARSE_H */
129
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