Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 1 | #include <linux/fs.h> |
| 2 | #include <linux/types.h> |
| 3 | #include "ctree.h" |
| 4 | #include "disk-io.h" |
| 5 | #include "btrfs_inode.h" |
| 6 | #include "print-tree.h" |
| 7 | #include "export.h" |
| 8 | #include "compat.h" |
| 9 | |
Chris Mason | d397712 | 2009-01-05 21:25:51 -0500 | [diff] [blame] | 10 | #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \ |
| 11 | parent_objectid) / 4) |
| 12 | #define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \ |
| 13 | parent_root_objectid) / 4) |
| 14 | #define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4) |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 15 | |
| 16 | static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, |
| 17 | int connectable) |
| 18 | { |
| 19 | struct btrfs_fid *fid = (struct btrfs_fid *)fh; |
| 20 | struct inode *inode = dentry->d_inode; |
| 21 | int len = *max_len; |
| 22 | int type; |
| 23 | |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 24 | if (connectable && (len < BTRFS_FID_SIZE_CONNECTABLE)) { |
| 25 | *max_len = BTRFS_FID_SIZE_CONNECTABLE; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 26 | return 255; |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 27 | } else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) { |
| 28 | *max_len = BTRFS_FID_SIZE_NON_CONNECTABLE; |
| 29 | return 255; |
| 30 | } |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 31 | |
| 32 | len = BTRFS_FID_SIZE_NON_CONNECTABLE; |
| 33 | type = FILEID_BTRFS_WITHOUT_PARENT; |
| 34 | |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 35 | fid->objectid = btrfs_ino(inode); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 36 | fid->root_objectid = BTRFS_I(inode)->root->objectid; |
| 37 | fid->gen = inode->i_generation; |
| 38 | |
| 39 | if (connectable && !S_ISDIR(inode->i_mode)) { |
| 40 | struct inode *parent; |
| 41 | u64 parent_root_id; |
| 42 | |
| 43 | spin_lock(&dentry->d_lock); |
| 44 | |
| 45 | parent = dentry->d_parent->d_inode; |
| 46 | fid->parent_objectid = BTRFS_I(parent)->location.objectid; |
| 47 | fid->parent_gen = parent->i_generation; |
| 48 | parent_root_id = BTRFS_I(parent)->root->objectid; |
| 49 | |
| 50 | spin_unlock(&dentry->d_lock); |
| 51 | |
| 52 | if (parent_root_id != fid->root_objectid) { |
| 53 | fid->parent_root_objectid = parent_root_id; |
| 54 | len = BTRFS_FID_SIZE_CONNECTABLE_ROOT; |
| 55 | type = FILEID_BTRFS_WITH_PARENT_ROOT; |
| 56 | } else { |
| 57 | len = BTRFS_FID_SIZE_CONNECTABLE; |
| 58 | type = FILEID_BTRFS_WITH_PARENT; |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | *max_len = len; |
| 63 | return type; |
| 64 | } |
| 65 | |
| 66 | static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 67 | u64 root_objectid, u32 generation, |
| 68 | int check_generation) |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 69 | { |
Al Viro | 815745c | 2011-11-17 15:40:49 -0500 | [diff] [blame] | 70 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 71 | struct btrfs_root *root; |
| 72 | struct inode *inode; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 73 | struct btrfs_key key; |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 74 | int index; |
| 75 | int err = 0; |
| 76 | |
| 77 | if (objectid < BTRFS_FIRST_FREE_OBJECTID) |
| 78 | return ERR_PTR(-ESTALE); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 79 | |
David Woodhouse | 2d4d9fbd | 2008-08-19 22:20:17 +0100 | [diff] [blame] | 80 | key.objectid = root_objectid; |
| 81 | btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
| 82 | key.offset = (u64)-1; |
| 83 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 84 | index = srcu_read_lock(&fs_info->subvol_srcu); |
| 85 | |
| 86 | root = btrfs_read_fs_root_no_name(fs_info, &key); |
| 87 | if (IS_ERR(root)) { |
| 88 | err = PTR_ERR(root); |
| 89 | goto fail; |
| 90 | } |
| 91 | |
| 92 | if (btrfs_root_refs(&root->root_item) == 0) { |
| 93 | err = -ENOENT; |
| 94 | goto fail; |
| 95 | } |
David Woodhouse | 2d4d9fbd | 2008-08-19 22:20:17 +0100 | [diff] [blame] | 96 | |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 97 | key.objectid = objectid; |
| 98 | btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); |
| 99 | key.offset = 0; |
| 100 | |
Josef Bacik | 73f7341 | 2009-12-04 17:38:27 +0000 | [diff] [blame] | 101 | inode = btrfs_iget(sb, &key, root, NULL); |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 102 | if (IS_ERR(inode)) { |
| 103 | err = PTR_ERR(inode); |
| 104 | goto fail; |
| 105 | } |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 106 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 107 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
| 108 | |
| 109 | if (check_generation && generation != inode->i_generation) { |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 110 | iput(inode); |
| 111 | return ERR_PTR(-ESTALE); |
| 112 | } |
| 113 | |
Al Viro | af53d29 | 2010-12-20 10:56:06 -0500 | [diff] [blame] | 114 | return d_obtain_alias(inode); |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 115 | fail: |
| 116 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
| 117 | return ERR_PTR(err); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh, |
| 121 | int fh_len, int fh_type) |
| 122 | { |
| 123 | struct btrfs_fid *fid = (struct btrfs_fid *) fh; |
| 124 | u64 objectid, root_objectid; |
| 125 | u32 generation; |
| 126 | |
| 127 | if (fh_type == FILEID_BTRFS_WITH_PARENT) { |
| 128 | if (fh_len != BTRFS_FID_SIZE_CONNECTABLE) |
| 129 | return NULL; |
| 130 | root_objectid = fid->root_objectid; |
| 131 | } else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) { |
| 132 | if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) |
| 133 | return NULL; |
| 134 | root_objectid = fid->parent_root_objectid; |
| 135 | } else |
| 136 | return NULL; |
| 137 | |
| 138 | objectid = fid->parent_objectid; |
| 139 | generation = fid->parent_gen; |
| 140 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 141 | return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 142 | } |
| 143 | |
| 144 | static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh, |
| 145 | int fh_len, int fh_type) |
| 146 | { |
| 147 | struct btrfs_fid *fid = (struct btrfs_fid *) fh; |
| 148 | u64 objectid, root_objectid; |
| 149 | u32 generation; |
| 150 | |
| 151 | if ((fh_type != FILEID_BTRFS_WITH_PARENT || |
| 152 | fh_len != BTRFS_FID_SIZE_CONNECTABLE) && |
| 153 | (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT || |
| 154 | fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) && |
| 155 | (fh_type != FILEID_BTRFS_WITHOUT_PARENT || |
| 156 | fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE)) |
| 157 | return NULL; |
| 158 | |
| 159 | objectid = fid->objectid; |
| 160 | root_objectid = fid->root_objectid; |
| 161 | generation = fid->gen; |
| 162 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 163 | return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 164 | } |
| 165 | |
| 166 | static struct dentry *btrfs_get_parent(struct dentry *child) |
| 167 | { |
| 168 | struct inode *dir = child->d_inode; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 169 | struct btrfs_root *root = BTRFS_I(dir)->root; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 170 | struct btrfs_path *path; |
| 171 | struct extent_buffer *leaf; |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 172 | struct btrfs_root_ref *ref; |
| 173 | struct btrfs_key key; |
| 174 | struct btrfs_key found_key; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 175 | int ret; |
| 176 | |
| 177 | path = btrfs_alloc_path(); |
liubo | 2a29edc | 2011-01-26 06:22:08 +0000 | [diff] [blame] | 178 | if (!path) |
| 179 | return ERR_PTR(-ENOMEM); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 180 | |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 181 | if (btrfs_ino(dir) == BTRFS_FIRST_FREE_OBJECTID) { |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 182 | key.objectid = root->root_key.objectid; |
| 183 | key.type = BTRFS_ROOT_BACKREF_KEY; |
| 184 | key.offset = (u64)-1; |
| 185 | root = root->fs_info->tree_root; |
| 186 | } else { |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 187 | key.objectid = btrfs_ino(dir); |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 188 | key.type = BTRFS_INODE_REF_KEY; |
| 189 | key.offset = (u64)-1; |
| 190 | } |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 191 | |
David Woodhouse | 87acb4e | 2008-08-18 22:50:22 +0100 | [diff] [blame] | 192 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 193 | if (ret < 0) |
| 194 | goto fail; |
| 195 | |
| 196 | BUG_ON(ret == 0); |
| 197 | if (path->slots[0] == 0) { |
| 198 | ret = -ENOENT; |
| 199 | goto fail; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 200 | } |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 201 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 202 | path->slots[0]--; |
| 203 | leaf = path->nodes[0]; |
| 204 | |
| 205 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 206 | if (found_key.objectid != key.objectid || found_key.type != key.type) { |
| 207 | ret = -ENOENT; |
| 208 | goto fail; |
| 209 | } |
| 210 | |
| 211 | if (found_key.type == BTRFS_ROOT_BACKREF_KEY) { |
| 212 | ref = btrfs_item_ptr(leaf, path->slots[0], |
| 213 | struct btrfs_root_ref); |
| 214 | key.objectid = btrfs_root_ref_dirid(leaf, ref); |
| 215 | } else { |
| 216 | key.objectid = found_key.offset; |
| 217 | } |
David Woodhouse | 87acb4e | 2008-08-18 22:50:22 +0100 | [diff] [blame] | 218 | btrfs_free_path(path); |
| 219 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 220 | if (found_key.type == BTRFS_ROOT_BACKREF_KEY) { |
| 221 | return btrfs_get_dentry(root->fs_info->sb, key.objectid, |
| 222 | found_key.offset, 0, 0); |
| 223 | } |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 224 | |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 225 | key.type = BTRFS_INODE_ITEM_KEY; |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 226 | key.offset = 0; |
Al Viro | af53d29 | 2010-12-20 10:56:06 -0500 | [diff] [blame] | 227 | return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL)); |
Yan, Zheng | 76dda93 | 2009-09-21 16:00:26 -0400 | [diff] [blame] | 228 | fail: |
| 229 | btrfs_free_path(path); |
| 230 | return ERR_PTR(ret); |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 231 | } |
| 232 | |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 233 | static int btrfs_get_name(struct dentry *parent, char *name, |
| 234 | struct dentry *child) |
| 235 | { |
| 236 | struct inode *inode = child->d_inode; |
| 237 | struct inode *dir = parent->d_inode; |
| 238 | struct btrfs_path *path; |
| 239 | struct btrfs_root *root = BTRFS_I(dir)->root; |
| 240 | struct btrfs_inode_ref *iref; |
| 241 | struct btrfs_root_ref *rref; |
| 242 | struct extent_buffer *leaf; |
| 243 | unsigned long name_ptr; |
| 244 | struct btrfs_key key; |
| 245 | int name_len; |
| 246 | int ret; |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 247 | u64 ino; |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 248 | |
| 249 | if (!dir || !inode) |
| 250 | return -EINVAL; |
| 251 | |
| 252 | if (!S_ISDIR(dir->i_mode)) |
| 253 | return -EINVAL; |
| 254 | |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 255 | ino = btrfs_ino(inode); |
| 256 | |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 257 | path = btrfs_alloc_path(); |
| 258 | if (!path) |
| 259 | return -ENOMEM; |
| 260 | path->leave_spinning = 1; |
| 261 | |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 262 | if (ino == BTRFS_FIRST_FREE_OBJECTID) { |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 263 | key.objectid = BTRFS_I(inode)->root->root_key.objectid; |
| 264 | key.type = BTRFS_ROOT_BACKREF_KEY; |
| 265 | key.offset = (u64)-1; |
| 266 | root = root->fs_info->tree_root; |
| 267 | } else { |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 268 | key.objectid = ino; |
| 269 | key.offset = btrfs_ino(dir); |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 270 | key.type = BTRFS_INODE_REF_KEY; |
| 271 | } |
| 272 | |
| 273 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 274 | if (ret < 0) { |
| 275 | btrfs_free_path(path); |
| 276 | return ret; |
| 277 | } else if (ret > 0) { |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 278 | if (ino == BTRFS_FIRST_FREE_OBJECTID) { |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 279 | path->slots[0]--; |
| 280 | } else { |
| 281 | btrfs_free_path(path); |
| 282 | return -ENOENT; |
| 283 | } |
| 284 | } |
| 285 | leaf = path->nodes[0]; |
| 286 | |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 287 | if (ino == BTRFS_FIRST_FREE_OBJECTID) { |
| 288 | rref = btrfs_item_ptr(leaf, path->slots[0], |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 289 | struct btrfs_root_ref); |
Li Zefan | 33345d01 | 2011-04-20 10:31:50 +0800 | [diff] [blame] | 290 | name_ptr = (unsigned long)(rref + 1); |
| 291 | name_len = btrfs_root_ref_name_len(leaf, rref); |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 292 | } else { |
| 293 | iref = btrfs_item_ptr(leaf, path->slots[0], |
| 294 | struct btrfs_inode_ref); |
| 295 | name_ptr = (unsigned long)(iref + 1); |
| 296 | name_len = btrfs_inode_ref_name_len(leaf, iref); |
| 297 | } |
| 298 | |
| 299 | read_extent_buffer(leaf, name, name_ptr, name_len); |
| 300 | btrfs_free_path(path); |
| 301 | |
| 302 | /* |
| 303 | * have to add the null termination to make sure that reconnect_path |
| 304 | * gets the right len for strlen |
| 305 | */ |
| 306 | name[name_len] = '\0'; |
| 307 | |
| 308 | return 0; |
| 309 | } |
| 310 | |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 311 | const struct export_operations btrfs_export_ops = { |
| 312 | .encode_fh = btrfs_encode_fh, |
| 313 | .fh_to_dentry = btrfs_fh_to_dentry, |
| 314 | .fh_to_parent = btrfs_fh_to_parent, |
| 315 | .get_parent = btrfs_get_parent, |
Josef Bacik | 2ede0da | 2010-11-17 18:54:54 +0000 | [diff] [blame] | 316 | .get_name = btrfs_get_name, |
Balaji Rao | be6e8dc | 2008-07-21 02:01:56 +0530 | [diff] [blame] | 317 | }; |