super.c 23.0 KB
Newer Older
1
#include <linux/module.h>
C
Chris Mason 已提交
2
#include <linux/buffer_head.h>
3 4 5 6 7 8 9 10
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
C
Chris Mason 已提交
11
#include <linux/mpage.h>
12
#include "ctree.h"
C
Chris Mason 已提交
13
#include "disk-io.h"
14
#include "transaction.h"
15 16

#define BTRFS_SUPER_MAGIC 0x9123682E
C
Chris Mason 已提交
17 18 19 20

static struct inode_operations btrfs_dir_inode_operations;
static struct super_operations btrfs_super_ops;
static struct file_operations btrfs_dir_file_operations;
C
Chris Mason 已提交
21 22 23
static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct file_operations btrfs_file_operations;
C
Chris Mason 已提交
24 25

static void btrfs_read_locked_inode(struct inode *inode)
26
{
C
Chris Mason 已提交
27 28 29 30
	struct btrfs_path path;
	struct btrfs_inode_item *inode_item;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	int ret;
C
Chris Mason 已提交
31

C
Chris Mason 已提交
32
	btrfs_init_path(&path);
C
Chris Mason 已提交
33 34
	mutex_lock(&root->fs_info->fs_mutex);

C
Chris Mason 已提交
35 36
	ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
	if (ret) {
C
Chris Mason 已提交
37
		btrfs_release_path(root, &path);
C
Chris Mason 已提交
38 39
		mutex_unlock(&root->fs_info->fs_mutex);
		make_bad_inode(inode);
C
Chris Mason 已提交
40 41 42 43 44
		return;
	}
	inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
				  path.slots[0],
				  struct btrfs_inode_item);
45

C
Chris Mason 已提交
46 47 48 49 50 51 52 53 54 55 56 57 58 59
	inode->i_mode = btrfs_inode_mode(inode_item);
	inode->i_nlink = btrfs_inode_nlink(inode_item);
	inode->i_uid = btrfs_inode_uid(inode_item);
	inode->i_gid = btrfs_inode_gid(inode_item);
	inode->i_size = btrfs_inode_size(inode_item);
	inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
	inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
	inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
	inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
	inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
	inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
	inode->i_blocks = btrfs_inode_nblocks(inode_item);
	inode->i_generation = btrfs_inode_generation(inode_item);
	btrfs_release_path(root, &path);
C
Chris Mason 已提交
60
	mutex_unlock(&root->fs_info->fs_mutex);
C
Chris Mason 已提交
61 62 63 64 65 66 67 68
	switch (inode->i_mode & S_IFMT) {
#if 0
	default:
		init_special_inode(inode, inode->i_mode,
				   btrfs_inode_rdev(inode_item));
		break;
#endif
	case S_IFREG:
C
Chris Mason 已提交
69 70 71
		inode->i_mapping->a_ops = &btrfs_aops;
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
C
Chris Mason 已提交
72 73 74 75 76 77 78 79
		break;
	case S_IFDIR:
		inode->i_op = &btrfs_dir_inode_operations;
		inode->i_fop = &btrfs_dir_file_operations;
		break;
	case S_IFLNK:
		// inode->i_op = &page_symlink_inode_operations;
		break;
80
	}
C
Chris Mason 已提交
81
	return;
82 83
}

C
Chris Mason 已提交
84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct btrfs_path path;
	struct btrfs_root *root;
	struct btrfs_trans_handle *trans;
	const char *name = dentry->d_name.name;
	int name_len = dentry->d_name.len;
	int ret;
	u64 objectid;
	struct btrfs_dir_item *di;

	btrfs_init_path(&path);
	root = btrfs_sb(dir->i_sb);
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);

	ret = btrfs_lookup_dir_item(trans, root, &path, dir->i_ino,
				    name, name_len, -1);
	if (ret < 0)
		goto err;
	if (ret > 0) {
		ret = -ENOENT;
		goto err;
	}
	di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			    struct btrfs_dir_item);
	objectid = btrfs_dir_objectid(di);

	ret = btrfs_del_item(trans, root, &path);
	BUG_ON(ret);
	dentry->d_inode->i_ctime = dir->i_ctime;
err:
	btrfs_release_path(root, &path);
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	if (ret == 0)
		inode_dec_link_count(dentry->d_inode);
	return ret;
}

static int btrfs_free_inode(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root,
			    struct inode *inode)
{
	u64 objectid = inode->i_ino;
	struct btrfs_path path;
	struct btrfs_inode_map_item *map;
	struct btrfs_key stat_data_key;
	int ret;
	clear_inode(inode);
	btrfs_init_path(&path);
	ret = btrfs_lookup_inode_map(trans, root, &path, objectid, -1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		btrfs_release_path(root, &path);
		goto error;
	}
	map = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			    struct btrfs_inode_map_item);
	btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
	ret = btrfs_del_item(trans, root->fs_info->inode_root, &path);
	BUG_ON(ret);
	btrfs_release_path(root, &path);
	btrfs_init_path(&path);

	ret = btrfs_lookup_inode(trans, root, &path, objectid, -1);
	BUG_ON(ret);
	ret = btrfs_del_item(trans, root, &path);
	BUG_ON(ret);
	btrfs_release_path(root, &path);
error:
	return ret;
}

C
Chris Mason 已提交
159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220
static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
				   struct btrfs_root *root,
				   struct inode *inode)
{
	int ret;
	struct btrfs_path path;
	struct btrfs_key key;
	struct btrfs_disk_key *found_key;
	struct btrfs_leaf *leaf;
	struct btrfs_file_extent_item *fi;
	u64 extent_start;
	u64 extent_num_blocks;

	/* FIXME, add redo link to tree so we don't leak on crash */
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
	while(1) {
		btrfs_init_path(&path);
		ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
		if (ret < 0) {
			btrfs_release_path(root, &path);
			goto error;
		}
		if (ret > 0) {
			BUG_ON(path.slots[0] == 0);
			path.slots[0]--;
		}
		leaf = btrfs_buffer_leaf(path.nodes[0]);
		found_key = &leaf->items[path.slots[0]].key;
		if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
			break;
		if (btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
			break;
		if (btrfs_disk_key_offset(found_key) < inode->i_size)
			break;
		/* FIXME: add extent truncation */
		if (btrfs_disk_key_offset(found_key) < inode->i_size)
			break;
		fi = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
				    path.slots[0],
				    struct btrfs_file_extent_item);
		extent_start = btrfs_file_extent_disk_blocknr(fi);
		extent_num_blocks = btrfs_file_extent_disk_num_blocks(fi);
		key.offset = btrfs_disk_key_offset(found_key) - 1;
		ret = btrfs_del_item(trans, root, &path);
		BUG_ON(ret);
		inode->i_blocks -= btrfs_file_extent_num_blocks(fi) >> 9;
		btrfs_release_path(root, &path);
		ret = btrfs_free_extent(trans, root, extent_start,
					extent_num_blocks, 0);
		BUG_ON(ret);
		if (btrfs_disk_key_offset(found_key) == 0)
			break;
	}
	btrfs_release_path(root, &path);
	ret = 0;
error:
	return ret;
}

C
Chris Mason 已提交
221 222 223 224
static void btrfs_delete_inode(struct inode *inode)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
C
Chris Mason 已提交
225 226
	int ret;

C
Chris Mason 已提交
227 228 229 230 231 232 233
	truncate_inode_pages(&inode->i_data, 0);
	if (is_bad_inode(inode)) {
		goto no_delete;
	}
	inode->i_size = 0;
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
C
Chris Mason 已提交
234 235 236 237
	if (S_ISREG(inode->i_mode)) {
		ret = btrfs_truncate_in_trans(trans, root, inode);
		BUG_ON(ret);
	}
C
Chris Mason 已提交
238 239 240 241 242 243 244 245
	btrfs_free_inode(trans, root, inode);
	btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return;
no_delete:
	clear_inode(inode);
}

C
Chris Mason 已提交
246 247 248 249 250 251 252 253 254 255 256 257 258
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
			      ino_t *ino)
{
	const char *name = dentry->d_name.name;
	int namelen = dentry->d_name.len;
	struct btrfs_dir_item *di;
	struct btrfs_path path;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	int ret;

	btrfs_init_path(&path);
	ret = btrfs_lookup_dir_item(NULL, root, &path, dir->i_ino, name,
				    namelen, 0);
259
	if (ret || !btrfs_match_dir_item_name(root, &path, name, namelen)) {
C
Chris Mason 已提交
260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
		*ino = 0;
		goto out;
	}
	di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			    struct btrfs_dir_item);
	*ino = btrfs_dir_objectid(di);
out:
	btrfs_release_path(root, &path);
	return ret;
}

static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
				   struct nameidata *nd)
{
	struct inode * inode;
	ino_t ino;
	int ret;

	if (dentry->d_name.len > BTRFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	ret = btrfs_inode_by_name(dir, dentry, &ino);
	if (ret < 0)
		return ERR_PTR(ret);
	inode = NULL;
	if (ino) {
		inode = iget(dir->i_sb, ino);
		if (!inode)
			return ERR_PTR(-EACCES);
	}
	return d_splice_alias(inode, dentry);
}

static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
	struct btrfs_path path;
	int ret;
	u32 nritems;
	struct btrfs_leaf *leaf;
	int slot;
	int advance;
	unsigned char d_type = DT_UNKNOWN;
307
	int over = 0;
C
Chris Mason 已提交
308 309 310 311 312 313 314 315 316 317

	key.objectid = inode->i_ino;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
	key.offset = filp->f_pos;
	btrfs_init_path(&path);
	ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
	if (ret < 0) {
		goto err;
	}
318
	advance = 0;
C
Chris Mason 已提交
319 320 321 322
	while(1) {
		leaf = btrfs_buffer_leaf(path.nodes[0]);
		nritems = btrfs_header_nritems(&leaf->header);
		slot = path.slots[0];
C
Chris Mason 已提交
323 324
		if (advance || slot >= nritems) {
			if (slot >= nritems -1) {
C
Chris Mason 已提交
325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341
				ret = btrfs_next_leaf(root, &path);
				if (ret)
					break;
				leaf = btrfs_buffer_leaf(path.nodes[0]);
				nritems = btrfs_header_nritems(&leaf->header);
				slot = path.slots[0];
			} else {
				slot++;
				path.slots[0]++;
			}
		}
		advance = 1;
		item = leaf->items + slot;
		if (btrfs_disk_key_objectid(&item->key) != key.objectid)
			break;
		if (btrfs_disk_key_type(&item->key) != BTRFS_DIR_ITEM_KEY)
			continue;
342 343
		if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
			continue;
C
Chris Mason 已提交
344 345

		advance = 1;
C
Chris Mason 已提交
346 347 348 349 350
		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		over = filldir(dirent, (const char *)(di + 1),
			       btrfs_dir_name_len(di),
			       btrfs_disk_key_offset(&item->key),
			       btrfs_dir_objectid(di), d_type);
351 352
		if (over) {
			filp->f_pos = btrfs_disk_key_offset(&item->key);
C
Chris Mason 已提交
353
			break;
354
		}
C
Chris Mason 已提交
355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
		filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
	}
	ret = 0;
err:
	btrfs_release_path(root, &path);
	return ret;
}

static void btrfs_put_super (struct super_block * sb)
{
	struct btrfs_root *root = btrfs_sb(sb);
	int ret;

	ret = close_ctree(root);
	if (ret) {
		printk("close ctree returns %d\n", ret);
	}
	sb->s_fs_info = NULL;
}
374 375 376 377

static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
{
	struct inode * inode;
C
Chris Mason 已提交
378 379 380 381
	struct dentry * root_dentry;
	struct btrfs_super_block *disk_super;
	struct buffer_head *bh;
	struct btrfs_root *root;
382 383 384 385 386

	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = BTRFS_SUPER_MAGIC;
C
Chris Mason 已提交
387
	sb->s_op = &btrfs_super_ops;
388
	sb->s_time_gran = 1;
C
Chris Mason 已提交
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406

	bh = sb_bread(sb, BTRFS_SUPER_INFO_OFFSET / sb->s_blocksize);
	if (!bh) {
		printk("btrfs: unable to read on disk super\n");
		return -EIO;
	}
	disk_super = (struct btrfs_super_block *)bh->b_data;
	root = open_ctree(sb, bh, disk_super);
	sb->s_fs_info = root;
	if (!root) {
		printk("btrfs: open_ctree failed\n");
		return -EIO;
	}
	printk("read in super total blocks %Lu root %Lu\n",
	       btrfs_super_total_blocks(disk_super),
	       btrfs_super_root_dir(disk_super));

	inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
407 408
	if (!inode)
		return -ENOMEM;
C
Chris Mason 已提交
409 410 411 412
	if (inode->i_state & I_NEW) {
		btrfs_read_locked_inode(inode);
		unlock_new_inode(inode);
	}
413

C
Chris Mason 已提交
414 415
	root_dentry = d_alloc_root(inode);
	if (!root_dentry) {
416 417 418
		iput(inode);
		return -ENOMEM;
	}
C
Chris Mason 已提交
419 420
	sb->s_root = root_dentry;

421 422 423
	return 0;
}

424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441
static void fill_inode_item(struct btrfs_inode_item *item,
			    struct inode *inode)
{
	btrfs_set_inode_uid(item, inode->i_uid);
	btrfs_set_inode_gid(item, inode->i_gid);
	btrfs_set_inode_size(item, inode->i_size);
	btrfs_set_inode_mode(item, inode->i_mode);
	btrfs_set_inode_nlink(item, inode->i_nlink);
	btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
	btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
	btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
	btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
	btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
	btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
	btrfs_set_inode_nblocks(item, inode->i_blocks);
	btrfs_set_inode_generation(item, inode->i_generation);
}

C
Chris Mason 已提交
442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486
static int btrfs_update_inode(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
			      struct inode *inode)
{
	struct btrfs_inode_item *inode_item;
	struct btrfs_path path;
	int ret;

	btrfs_init_path(&path);

	ret = btrfs_lookup_inode(trans, root, &path, inode->i_ino, 1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		goto failed;
	}

	inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
				  path.slots[0],
				  struct btrfs_inode_item);

	fill_inode_item(inode_item, inode);
	mark_buffer_dirty(path.nodes[0]);
failed:
	btrfs_release_path(root, &path);
	return 0;
}

static int btrfs_write_inode(struct inode *inode, int wait)
{
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	struct btrfs_trans_handle *trans;
	int ret;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_update_inode(trans, root, inode);
	if (wait)
		btrfs_commit_transaction(trans, root);
	else
		btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}

487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
				     struct inode *dir, int mode)
{
	struct inode *inode;
	struct btrfs_inode_item inode_item;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	struct btrfs_key key;
	int ret;
	u64 objectid;

	inode = new_inode(dir->i_sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

	ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
	BUG_ON(ret);

	inode->i_uid = current->fsuid;
	inode->i_gid = current->fsgid;
	inode->i_mode = mode;
	inode->i_ino = objectid;
	inode->i_blocks = 0;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	fill_inode_item(&inode_item, inode);

	key.objectid = objectid;
	key.flags = 0;
	key.offset = 0;
	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
	ret = btrfs_insert_inode_map(trans, root, objectid, &key);
	BUG_ON(ret);

	ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
	BUG_ON(ret);

	insert_inode_hash(inode);
	return inode;
}

static int btrfs_add_link(struct btrfs_trans_handle *trans,
			    struct dentry *dentry, struct inode *inode)
{
	int ret;
	ret = btrfs_insert_dir_item(trans, btrfs_sb(inode->i_sb),
				    dentry->d_name.name, dentry->d_name.len,
				    dentry->d_parent->d_inode->i_ino,
				    inode->i_ino, 0);
C
Chris Mason 已提交
534 535 536 537 538 539
	if (ret == 0) {
		dentry->d_parent->d_inode->i_size += dentry->d_name.len;
		ret = btrfs_update_inode(trans, btrfs_sb(inode->i_sb),
					 dentry->d_parent->d_inode);
	}

540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560
	return ret;
}

static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
			    struct dentry *dentry, struct inode *inode)
{
	int err = btrfs_add_link(trans, dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	return err;
}

static int btrfs_create(struct inode *dir, struct dentry *dentry,
			int mode, struct nameidata *nd)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	struct inode *inode;
	int err;
C
Chris Mason 已提交
561
	int drop_inode = 0;
562

C
Chris Mason 已提交
563
	mutex_lock(&root->fs_info->fs_mutex);
564 565 566 567
	trans = btrfs_start_transaction(root, 1);
	inode = btrfs_new_inode(trans, dir, mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
C
Chris Mason 已提交
568
		goto out_unlock;
569 570
	// FIXME mark the inode dirty
	err = btrfs_add_nondir(trans, dentry, inode);
C
Chris Mason 已提交
571 572
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
573 574 575 576 577
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
	}
578 579
	dir->i_sb->s_dirt = 1;
	btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
580 581
out_unlock:
	mutex_unlock(&root->fs_info->fs_mutex);
C
Chris Mason 已提交
582 583 584 585
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
586 587 588
	return err;
}

C
Chris Mason 已提交
589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
				struct inode *inode, struct inode *dir)
{
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	int ret;
	char buf[2];
	buf[0] = '.';
	buf[1] = '.';

	ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
				    inode->i_ino, 1);
	if (ret)
		goto error;
	ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
				    dir->i_ino, 1);
C
Chris Mason 已提交
604 605 606 607
	if (ret)
		goto error;
	inode->i_size = 3;
	ret = btrfs_update_inode(trans, root, inode);
C
Chris Mason 已提交
608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652
error:
	return ret;
}

static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct inode *inode;
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = btrfs_sb(dir->i_sb);
	int err = 0;
	int drop_on_err = 0;

	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	if (IS_ERR(trans)) {
		err = PTR_ERR(trans);
		goto out_unlock;
	}
	inode = btrfs_new_inode(trans, dir, S_IFDIR | mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fail;
	}
	drop_on_err = 1;
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;

	err = btrfs_make_empty_dir(trans, inode, dir);
	if (err)
		goto out_fail;
	err = btrfs_add_link(trans, dentry, inode);
	if (err)
		goto out_fail;
	d_instantiate(dentry, inode);
	drop_on_err = 0;

out_fail:
	btrfs_end_transaction(trans, root);
out_unlock:
	mutex_unlock(&root->fs_info->fs_mutex);
	if (drop_on_err)
		iput(inode);
	return err;
}

653 654 655 656 657
static int btrfs_sync_fs(struct super_block *sb, int wait)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root;
	int ret;
658

659
	sb->s_dirt = 0;
C
Chris Mason 已提交
660 661 662 663 664
	if (!wait) {
		filemap_flush(sb->s_bdev->bd_inode->i_mapping);
		return 0;
	}
	filemap_write_and_wait(sb->s_bdev->bd_inode->i_mapping);
665

666
	root = btrfs_sb(sb);
C
Chris Mason 已提交
667
	mutex_lock(&root->fs_info->fs_mutex);
668 669 670 671 672
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_commit_transaction(trans, root);
	sb->s_dirt = 0;
	BUG_ON(ret);
printk("btrfs sync_fs\n");
C
Chris Mason 已提交
673
	mutex_unlock(&root->fs_info->fs_mutex);
674 675 676
	return 0;
}

C
Chris Mason 已提交
677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759
static int btrfs_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *result, int create)
{
	int ret;
	int err = 0;
	u64 blocknr;
	u64 extent_start = 0;
	u64 extent_end = 0;
	u64 objectid = inode->i_ino;
	struct btrfs_path path;
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	struct btrfs_trans_handle *trans = NULL;
	struct btrfs_file_extent_item *item;
	struct btrfs_leaf *leaf;
	struct btrfs_disk_key *found_key;

	btrfs_init_path(&path);
	mutex_lock(&root->fs_info->fs_mutex);
	if (create)
		trans = btrfs_start_transaction(root, 1);


	ret = btrfs_lookup_file_extent(trans, root, &path,
				       inode->i_ino, iblock, 1, 0);
	if (ret < 0) {
		btrfs_release_path(root, &path);
		err = ret;
		goto out;
	}

	if (ret != 0) {
		if (path.slots[0] == 0) {
			btrfs_release_path(root, &path);
			goto allocate;
		}
		path.slots[0]--;
	}

	item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
			      struct btrfs_file_extent_item);
	leaf = btrfs_buffer_leaf(path.nodes[0]);
	blocknr = btrfs_file_extent_disk_blocknr(item);
	blocknr += btrfs_file_extent_offset(item);

	/* exact match found, use it */
	if (ret == 0) {
		err = 0;
		map_bh(result, inode->i_sb, blocknr);
		btrfs_release_path(root, &path);
		goto out;
	}

	/* are we inside the extent that was found? */
	found_key = &leaf->items[path.slots[0]].key;
	if (btrfs_disk_key_objectid(found_key) != objectid ||
	    btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) {
		extent_end = 0;
		extent_start = 0;
		btrfs_release_path(root, &path);
		goto allocate;
	}

	extent_start = btrfs_disk_key_offset(&leaf->items[path.slots[0]].key);
	extent_start += btrfs_file_extent_offset(item);
	extent_end = extent_start + btrfs_file_extent_num_blocks(item);
	btrfs_release_path(root, &path);
	if (iblock >= extent_start && iblock < extent_end) {
		err = 0;
		map_bh(result, inode->i_sb, blocknr + iblock - extent_start);
		goto out;
	}
allocate:
	/* ok, create a new extent */
	if (!create) {
		err = 0;
		goto out;
	}
	ret = btrfs_alloc_file_extent(trans, root, objectid, iblock,
				      1, extent_end, &blocknr);
	if (ret) {
		err = ret;
		goto out;
	}
C
Chris Mason 已提交
760 761
	inode->i_blocks += inode->i_sb->s_blocksize >> 9;
	set_buffer_new(result);
C
Chris Mason 已提交
762 763 764 765 766 767 768 769 770 771 772 773
	map_bh(result, inode->i_sb, blocknr);

out:
	if (trans)
		btrfs_end_transaction(trans, root);
	mutex_unlock(&root->fs_info->fs_mutex);
	return err;
}

static int btrfs_prepare_write(struct file *file, struct page *page,
			       unsigned from, unsigned to)
{
774
	return nobh_prepare_write(page, from, to, btrfs_get_block);
C
Chris Mason 已提交
775 776
}

C
Chris Mason 已提交
777 778 779 780 781
static void btrfs_write_super(struct super_block *sb)
{
	btrfs_sync_fs(sb, 1);
}

C
Chris Mason 已提交
782 783 784 785 786 787 788 789 790 791 792 793 794
static int btrfs_readpage(struct file *file, struct page *page)
{
	return mpage_readpage(page, btrfs_get_block);
}

static int btrfs_readpages(struct file *file, struct address_space *mapping,
			   struct list_head *pages, unsigned nr_pages)
{
	return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block);
}

static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
795
	return nobh_writepage(page, btrfs_get_block, wbc);
C
Chris Mason 已提交
796
}
C
Chris Mason 已提交
797

C
Chris Mason 已提交
798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821
static void btrfs_truncate(struct inode *inode)
{
	struct btrfs_root *root = btrfs_sb(inode->i_sb);
	int ret;
	struct btrfs_trans_handle *trans;

	if (!S_ISREG(inode->i_mode))
		return;
	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
		return;

	nobh_truncate_page(inode->i_mapping, inode->i_size);

	/* FIXME, add redo link to tree so we don't leak on crash */
	mutex_lock(&root->fs_info->fs_mutex);
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_truncate_in_trans(trans, root, inode);
	BUG_ON(ret);
	ret = btrfs_end_transaction(trans, root);
	BUG_ON(ret);
	mutex_unlock(&root->fs_info->fs_mutex);
	mark_inode_dirty(inode);
}

822 823 824 825 826 827 828 829 830 831 832 833 834 835 836
static int btrfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data,
			   btrfs_fill_super, mnt);
}

static struct file_system_type btrfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "btrfs",
	.get_sb		= btrfs_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

C
Chris Mason 已提交
837 838
static struct super_operations btrfs_super_ops = {
	.statfs		= simple_statfs,
C
Chris Mason 已提交
839
	.delete_inode	= btrfs_delete_inode,
C
Chris Mason 已提交
840 841
	.put_super	= btrfs_put_super,
	.read_inode	= btrfs_read_locked_inode,
842 843
	.write_super	= btrfs_write_super,
	.sync_fs	= btrfs_sync_fs,
C
Chris Mason 已提交
844
	.write_inode	= btrfs_write_inode,
C
Chris Mason 已提交
845 846 847 848
};

static struct inode_operations btrfs_dir_inode_operations = {
	.lookup		= btrfs_lookup,
849
	.create		= btrfs_create,
C
Chris Mason 已提交
850
	.unlink		= btrfs_unlink,
C
Chris Mason 已提交
851
	.mkdir		= btrfs_mkdir,
C
Chris Mason 已提交
852 853 854 855 856 857 858 859
};

static struct file_operations btrfs_dir_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.readdir	= btrfs_readdir,
};

C
Chris Mason 已提交
860 861 862 863 864 865
static struct address_space_operations btrfs_aops = {
	.readpage	= btrfs_readpage,
	.readpages	= btrfs_readpages,
	.writepage	= btrfs_writepage,
	.sync_page	= block_sync_page,
	.prepare_write	= btrfs_prepare_write,
866
	.commit_write	= nobh_commit_write,
C
Chris Mason 已提交
867 868 869
};

static struct inode_operations btrfs_file_inode_operations = {
C
Chris Mason 已提交
870
	.truncate	= btrfs_truncate,
C
Chris Mason 已提交
871 872 873 874 875 876 877 878 879 880 881 882 883 884
};

static struct file_operations btrfs_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= do_sync_read,
	.write		= do_sync_write,
	.aio_read	= generic_file_aio_read,
	.aio_write	= generic_file_aio_write,
	.mmap		= generic_file_mmap,
	.open		= generic_file_open,
	.sendfile	= generic_file_sendfile,
	.splice_read	= generic_file_splice_read,
	.splice_write	= generic_file_splice_write,
};
C
Chris Mason 已提交
885

886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
static int __init init_btrfs_fs(void)
{
	printk("btrfs loaded!\n");
	return register_filesystem(&btrfs_fs_type);
}

static void __exit exit_btrfs_fs(void)
{
	unregister_filesystem(&btrfs_fs_type);
	printk("btrfs unloaded\n");
}

module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)

MODULE_LICENSE("GPL");