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2e635a27 CM |
1 | #include <linux/module.h> |
2 | #include <linux/fs.h> | |
3 | #include <linux/pagemap.h> | |
4 | #include <linux/highmem.h> | |
5 | #include <linux/time.h> | |
6 | #include <linux/init.h> | |
7 | #include <linux/string.h> | |
8 | #include <linux/smp_lock.h> | |
9 | #include <linux/backing-dev.h> | |
10 | #include "ctree.h" | |
11 | ||
12 | #define BTRFS_SUPER_MAGIC 0x9123682E | |
13 | #if 0 | |
14 | /* some random number */ | |
15 | ||
16 | static struct super_operations ramfs_ops; | |
17 | static struct inode_operations ramfs_dir_inode_operations; | |
18 | ||
19 | static struct backing_dev_info ramfs_backing_dev_info = { | |
20 | .ra_pages = 0, /* No readahead */ | |
21 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK | | |
22 | BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY | | |
23 | BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP, | |
24 | }; | |
25 | ||
26 | struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev) | |
27 | { | |
28 | struct inode * inode = new_inode(sb); | |
29 | ||
30 | if (inode) { | |
31 | inode->i_mode = mode; | |
32 | inode->i_uid = current->fsuid; | |
33 | inode->i_gid = current->fsgid; | |
34 | inode->i_blocks = 0; | |
35 | inode->i_mapping->a_ops = &ramfs_aops; | |
36 | inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info; | |
37 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
38 | switch (mode & S_IFMT) { | |
39 | default: | |
40 | init_special_inode(inode, mode, dev); | |
41 | break; | |
42 | case S_IFREG: | |
43 | inode->i_op = &ramfs_file_inode_operations; | |
44 | inode->i_fop = &ramfs_file_operations; | |
45 | break; | |
46 | case S_IFDIR: | |
47 | inode->i_op = &ramfs_dir_inode_operations; | |
48 | inode->i_fop = &simple_dir_operations; | |
49 | ||
50 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
51 | inc_nlink(inode); | |
52 | break; | |
53 | case S_IFLNK: | |
54 | inode->i_op = &page_symlink_inode_operations; | |
55 | break; | |
56 | } | |
57 | } | |
58 | return inode; | |
59 | } | |
60 | ||
61 | /* | |
62 | * File creation. Allocate an inode, and we're done.. | |
63 | */ | |
64 | /* SMP-safe */ | |
65 | static int | |
66 | ramfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
67 | { | |
68 | struct inode * inode = ramfs_get_inode(dir->i_sb, mode, dev); | |
69 | int error = -ENOSPC; | |
70 | ||
71 | if (inode) { | |
72 | if (dir->i_mode & S_ISGID) { | |
73 | inode->i_gid = dir->i_gid; | |
74 | if (S_ISDIR(mode)) | |
75 | inode->i_mode |= S_ISGID; | |
76 | } | |
77 | d_instantiate(dentry, inode); | |
78 | dget(dentry); /* Extra count - pin the dentry in core */ | |
79 | error = 0; | |
80 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; | |
81 | } | |
82 | return error; | |
83 | } | |
84 | ||
85 | static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, int mode) | |
86 | { | |
87 | int retval = ramfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
88 | if (!retval) | |
89 | inc_nlink(dir); | |
90 | return retval; | |
91 | } | |
92 | ||
93 | static int ramfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
94 | { | |
95 | return ramfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
96 | } | |
97 | ||
98 | static int ramfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname) | |
99 | { | |
100 | struct inode *inode; | |
101 | int error = -ENOSPC; | |
102 | ||
103 | inode = ramfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0); | |
104 | if (inode) { | |
105 | int l = strlen(symname)+1; | |
106 | error = page_symlink(inode, symname, l); | |
107 | if (!error) { | |
108 | if (dir->i_mode & S_ISGID) | |
109 | inode->i_gid = dir->i_gid; | |
110 | d_instantiate(dentry, inode); | |
111 | dget(dentry); | |
112 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; | |
113 | } else | |
114 | iput(inode); | |
115 | } | |
116 | return error; | |
117 | } | |
118 | ||
119 | static struct inode_operations ramfs_dir_inode_operations = { | |
120 | .create = ramfs_create, | |
121 | .lookup = simple_lookup, | |
122 | .link = simple_link, | |
123 | .unlink = simple_unlink, | |
124 | .symlink = ramfs_symlink, | |
125 | .mkdir = ramfs_mkdir, | |
126 | .rmdir = simple_rmdir, | |
127 | .mknod = ramfs_mknod, | |
128 | .rename = simple_rename, | |
129 | }; | |
130 | #endif | |
131 | ||
132 | struct inode *btrfs_get_inode(struct super_block *sb, int mode, dev_t dev) | |
133 | { | |
134 | struct inode * inode = new_inode(sb); | |
135 | ||
136 | if (inode) { | |
137 | inode->i_mode = mode; | |
138 | inode->i_uid = current->fsuid; | |
139 | inode->i_gid = current->fsgid; | |
140 | inode->i_blocks = 0; | |
141 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
142 | } | |
143 | return inode; | |
144 | } | |
145 | ||
146 | static struct super_operations btrfs_ops = { | |
147 | .statfs = simple_statfs, | |
148 | .drop_inode = generic_delete_inode, | |
149 | }; | |
150 | ||
151 | static int btrfs_fill_super(struct super_block * sb, void * data, int silent) | |
152 | { | |
153 | struct inode * inode; | |
154 | struct dentry * root; | |
155 | ||
156 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
157 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
158 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
159 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
160 | sb->s_op = &btrfs_ops; | |
161 | sb->s_time_gran = 1; | |
162 | inode = btrfs_get_inode(sb, S_IFDIR | 0755, 0); | |
163 | if (!inode) | |
164 | return -ENOMEM; | |
165 | ||
166 | root = d_alloc_root(inode); | |
167 | if (!root) { | |
168 | iput(inode); | |
169 | return -ENOMEM; | |
170 | } | |
171 | sb->s_root = root; | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static int btrfs_get_sb(struct file_system_type *fs_type, | |
176 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
177 | { | |
178 | return get_sb_bdev(fs_type, flags, dev_name, data, | |
179 | btrfs_fill_super, mnt); | |
180 | } | |
181 | ||
182 | static struct file_system_type btrfs_fs_type = { | |
183 | .owner = THIS_MODULE, | |
184 | .name = "btrfs", | |
185 | .get_sb = btrfs_get_sb, | |
186 | .kill_sb = kill_block_super, | |
187 | .fs_flags = FS_REQUIRES_DEV, | |
188 | }; | |
189 | ||
190 | static int __init init_btrfs_fs(void) | |
191 | { | |
192 | printk("btrfs loaded!\n"); | |
193 | return register_filesystem(&btrfs_fs_type); | |
194 | } | |
195 | ||
196 | static void __exit exit_btrfs_fs(void) | |
197 | { | |
198 | unregister_filesystem(&btrfs_fs_type); | |
199 | printk("btrfs unloaded\n"); | |
200 | } | |
201 | ||
202 | module_init(init_btrfs_fs) | |
203 | module_exit(exit_btrfs_fs) | |
204 | ||
205 | MODULE_LICENSE("GPL"); |