1 #include <linux/module.h>
2 #include <linux/buffer_head.h>
4 #include <linux/pagemap.h>
5 #include <linux/highmem.h>
6 #include <linux/time.h>
7 #include <linux/init.h>
8 #include <linux/string.h>
9 #include <linux/smp_lock.h>
10 #include <linux/backing-dev.h>
11 #include <linux/mpage.h>
12 #include <linux/swap.h>
13 #include <linux/writeback.h>
16 #include "transaction.h"
18 #define BTRFS_SUPER_MAGIC 0x9123682E
20 static struct inode_operations btrfs_dir_inode_operations;
21 static struct super_operations btrfs_super_ops;
22 static struct file_operations btrfs_dir_file_operations;
23 static struct inode_operations btrfs_file_inode_operations;
24 static struct address_space_operations btrfs_aops;
25 static struct file_operations btrfs_file_operations;
27 static void btrfs_read_locked_inode(struct inode *inode)
29 struct btrfs_path path;
30 struct btrfs_inode_item *inode_item;
31 struct btrfs_root *root = btrfs_sb(inode->i_sb);
34 btrfs_init_path(&path);
35 mutex_lock(&root->fs_info->fs_mutex);
37 ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
39 btrfs_release_path(root, &path);
40 mutex_unlock(&root->fs_info->fs_mutex);
41 make_bad_inode(inode);
44 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
46 struct btrfs_inode_item);
48 inode->i_mode = btrfs_inode_mode(inode_item);
49 inode->i_nlink = btrfs_inode_nlink(inode_item);
50 inode->i_uid = btrfs_inode_uid(inode_item);
51 inode->i_gid = btrfs_inode_gid(inode_item);
52 inode->i_size = btrfs_inode_size(inode_item);
53 inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
54 inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
55 inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
56 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
57 inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
58 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
59 inode->i_blocks = btrfs_inode_nblocks(inode_item);
60 inode->i_generation = btrfs_inode_generation(inode_item);
61 btrfs_release_path(root, &path);
62 mutex_unlock(&root->fs_info->fs_mutex);
63 switch (inode->i_mode & S_IFMT) {
66 init_special_inode(inode, inode->i_mode,
67 btrfs_inode_rdev(inode_item));
71 inode->i_mapping->a_ops = &btrfs_aops;
72 inode->i_fop = &btrfs_file_operations;
73 inode->i_op = &btrfs_file_inode_operations;
76 inode->i_op = &btrfs_dir_inode_operations;
77 inode->i_fop = &btrfs_dir_file_operations;
80 // inode->i_op = &page_symlink_inode_operations;
86 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
87 struct btrfs_root *root,
89 struct dentry *dentry)
91 struct btrfs_path path;
92 const char *name = dentry->d_name.name;
93 int name_len = dentry->d_name.len;
96 struct btrfs_dir_item *di;
98 btrfs_init_path(&path);
99 ret = btrfs_lookup_dir_item(trans, root, &path, dir->i_ino,
107 di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
108 struct btrfs_dir_item);
109 objectid = btrfs_dir_objectid(di);
111 ret = btrfs_del_item(trans, root, &path);
113 dentry->d_inode->i_ctime = dir->i_ctime;
115 btrfs_release_path(root, &path);
117 inode_dec_link_count(dentry->d_inode);
121 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
123 struct btrfs_root *root;
124 struct btrfs_trans_handle *trans;
127 root = btrfs_sb(dir->i_sb);
128 mutex_lock(&root->fs_info->fs_mutex);
129 trans = btrfs_start_transaction(root, 1);
130 ret = btrfs_unlink_trans(trans, root, dir, dentry);
131 btrfs_end_transaction(trans, root);
132 mutex_unlock(&root->fs_info->fs_mutex);
136 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
138 struct inode *inode = dentry->d_inode;
141 struct btrfs_root *root = btrfs_sb(dir->i_sb);
142 struct btrfs_path path;
143 struct btrfs_key key;
144 struct btrfs_trans_handle *trans;
145 struct btrfs_disk_key *found_key;
146 struct btrfs_leaf *leaf;
148 btrfs_init_path(&path);
149 mutex_lock(&root->fs_info->fs_mutex);
150 trans = btrfs_start_transaction(root, 1);
151 key.objectid = inode->i_ino;
152 key.offset = (u64)-1;
154 btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
155 ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
162 BUG_ON(path.slots[0] == 0);
164 leaf = btrfs_buffer_leaf(path.nodes[0]);
165 found_key = &leaf->items[path.slots[0]].key;
166 if (btrfs_disk_key_objectid(found_key) != inode->i_ino) {
170 if (btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
171 btrfs_disk_key_offset(found_key) != 2) {
175 ret = btrfs_del_item(trans, root, &path);
177 btrfs_release_path(root, &path);
179 ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
188 ret = btrfs_del_item(trans, root, &path);
193 btrfs_release_path(root, &path);
195 /* now the directory is empty */
196 err = btrfs_unlink_trans(trans, root, dir, dentry);
201 mutex_unlock(&root->fs_info->fs_mutex);
202 ret = btrfs_end_transaction(trans, root);
208 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
209 struct btrfs_root *root,
212 u64 objectid = inode->i_ino;
213 struct btrfs_path path;
214 struct btrfs_inode_map_item *map;
215 struct btrfs_key stat_data_key;
218 btrfs_init_path(&path);
219 ret = btrfs_lookup_inode_map(trans, root, &path, objectid, -1);
223 btrfs_release_path(root, &path);
226 map = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
227 struct btrfs_inode_map_item);
228 btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
229 ret = btrfs_del_item(trans, root->fs_info->inode_root, &path);
231 btrfs_release_path(root, &path);
232 btrfs_init_path(&path);
234 ret = btrfs_lookup_inode(trans, root, &path, objectid, -1);
236 ret = btrfs_del_item(trans, root, &path);
238 btrfs_release_path(root, &path);
243 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
244 struct btrfs_root *root,
248 struct btrfs_path path;
249 struct btrfs_key key;
250 struct btrfs_disk_key *found_key;
251 struct btrfs_leaf *leaf;
252 struct btrfs_file_extent_item *fi = NULL;
253 u64 extent_start = 0;
254 u64 extent_num_blocks = 0;
257 /* FIXME, add redo link to tree so we don't leak on crash */
258 key.objectid = inode->i_ino;
259 key.offset = (u64)-1;
261 btrfs_set_key_type(&key, BTRFS_CSUM_ITEM_KEY);
263 btrfs_init_path(&path);
264 ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
266 btrfs_release_path(root, &path);
270 BUG_ON(path.slots[0] == 0);
273 leaf = btrfs_buffer_leaf(path.nodes[0]);
274 found_key = &leaf->items[path.slots[0]].key;
275 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
277 if (btrfs_disk_key_type(found_key) != BTRFS_CSUM_ITEM_KEY &&
278 btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
280 if (btrfs_disk_key_offset(found_key) < inode->i_size)
282 if (btrfs_disk_key_type(found_key) == BTRFS_EXTENT_DATA_KEY) {
283 fi = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
285 struct btrfs_file_extent_item);
286 extent_start = btrfs_file_extent_disk_blocknr(fi);
288 btrfs_file_extent_disk_num_blocks(fi);
290 btrfs_file_extent_num_blocks(fi) >> 9;
295 ret = btrfs_del_item(trans, root, &path);
297 btrfs_release_path(root, &path);
299 ret = btrfs_free_extent(trans, root, extent_start,
300 extent_num_blocks, 0);
304 btrfs_release_path(root, &path);
310 static void btrfs_delete_inode(struct inode *inode)
312 struct btrfs_trans_handle *trans;
313 struct btrfs_root *root = btrfs_sb(inode->i_sb);
316 truncate_inode_pages(&inode->i_data, 0);
317 if (is_bad_inode(inode)) {
321 mutex_lock(&root->fs_info->fs_mutex);
322 trans = btrfs_start_transaction(root, 1);
323 if (S_ISREG(inode->i_mode)) {
324 ret = btrfs_truncate_in_trans(trans, root, inode);
327 btrfs_free_inode(trans, root, inode);
328 btrfs_end_transaction(trans, root);
329 mutex_unlock(&root->fs_info->fs_mutex);
335 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
338 const char *name = dentry->d_name.name;
339 int namelen = dentry->d_name.len;
340 struct btrfs_dir_item *di;
341 struct btrfs_path path;
342 struct btrfs_root *root = btrfs_sb(dir->i_sb);
345 btrfs_init_path(&path);
346 ret = btrfs_lookup_dir_item(NULL, root, &path, dir->i_ino, name,
348 if (ret || !btrfs_match_dir_item_name(root, &path, name, namelen)) {
352 di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
353 struct btrfs_dir_item);
354 *ino = btrfs_dir_objectid(di);
356 btrfs_release_path(root, &path);
360 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
361 struct nameidata *nd)
363 struct inode * inode;
367 if (dentry->d_name.len > BTRFS_NAME_LEN)
368 return ERR_PTR(-ENAMETOOLONG);
370 ret = btrfs_inode_by_name(dir, dentry, &ino);
375 inode = iget(dir->i_sb, ino);
377 return ERR_PTR(-EACCES);
379 return d_splice_alias(inode, dentry);
382 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
384 struct inode *inode = filp->f_path.dentry->d_inode;
385 struct btrfs_root *root = btrfs_sb(inode->i_sb);
386 struct btrfs_item *item;
387 struct btrfs_dir_item *di;
388 struct btrfs_key key;
389 struct btrfs_path path;
392 struct btrfs_leaf *leaf;
395 unsigned char d_type = DT_UNKNOWN;
398 key.objectid = inode->i_ino;
400 btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
401 key.offset = filp->f_pos;
402 btrfs_init_path(&path);
403 ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
409 leaf = btrfs_buffer_leaf(path.nodes[0]);
410 nritems = btrfs_header_nritems(&leaf->header);
411 slot = path.slots[0];
412 if (advance || slot >= nritems) {
413 if (slot >= nritems -1) {
414 ret = btrfs_next_leaf(root, &path);
417 leaf = btrfs_buffer_leaf(path.nodes[0]);
418 nritems = btrfs_header_nritems(&leaf->header);
419 slot = path.slots[0];
426 item = leaf->items + slot;
427 if (btrfs_disk_key_objectid(&item->key) != key.objectid)
429 if (btrfs_disk_key_type(&item->key) != BTRFS_DIR_ITEM_KEY)
431 if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
435 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
436 over = filldir(dirent, (const char *)(di + 1),
437 btrfs_dir_name_len(di),
438 btrfs_disk_key_offset(&item->key),
439 btrfs_dir_objectid(di), d_type);
441 filp->f_pos = btrfs_disk_key_offset(&item->key);
444 filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
448 btrfs_release_path(root, &path);
452 static void btrfs_put_super (struct super_block * sb)
454 struct btrfs_root *root = btrfs_sb(sb);
457 ret = close_ctree(root);
459 printk("close ctree returns %d\n", ret);
461 sb->s_fs_info = NULL;
464 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
466 struct inode * inode;
467 struct dentry * root_dentry;
468 struct btrfs_super_block *disk_super;
469 struct buffer_head *bh;
470 struct btrfs_root *root;
472 sb->s_maxbytes = MAX_LFS_FILESIZE;
473 sb->s_blocksize = PAGE_CACHE_SIZE;
474 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
475 sb->s_magic = BTRFS_SUPER_MAGIC;
476 sb->s_op = &btrfs_super_ops;
479 bh = sb_bread(sb, BTRFS_SUPER_INFO_OFFSET / sb->s_blocksize);
481 printk("btrfs: unable to read on disk super\n");
484 disk_super = (struct btrfs_super_block *)bh->b_data;
485 root = open_ctree(sb, bh, disk_super);
488 printk("btrfs: open_ctree failed\n");
491 sb->s_fs_info = root;
492 disk_super = root->fs_info->disk_super;
493 printk("read in super total blocks %Lu root %Lu\n",
494 btrfs_super_total_blocks(disk_super),
495 btrfs_super_root_dir(disk_super));
497 inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
500 if (inode->i_state & I_NEW) {
501 btrfs_read_locked_inode(inode);
502 unlock_new_inode(inode);
505 root_dentry = d_alloc_root(inode);
510 sb->s_root = root_dentry;
515 static void fill_inode_item(struct btrfs_inode_item *item,
518 btrfs_set_inode_uid(item, inode->i_uid);
519 btrfs_set_inode_gid(item, inode->i_gid);
520 btrfs_set_inode_size(item, inode->i_size);
521 btrfs_set_inode_mode(item, inode->i_mode);
522 btrfs_set_inode_nlink(item, inode->i_nlink);
523 btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
524 btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
525 btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
526 btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
527 btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
528 btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
529 btrfs_set_inode_nblocks(item, inode->i_blocks);
530 btrfs_set_inode_generation(item, inode->i_generation);
533 static int btrfs_update_inode(struct btrfs_trans_handle *trans,
534 struct btrfs_root *root,
537 struct btrfs_inode_item *inode_item;
538 struct btrfs_path path;
541 btrfs_init_path(&path);
543 ret = btrfs_lookup_inode(trans, root, &path, inode->i_ino, 1);
550 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
552 struct btrfs_inode_item);
554 fill_inode_item(inode_item, inode);
555 mark_buffer_dirty(path.nodes[0]);
557 btrfs_release_path(root, &path);
561 static int btrfs_write_inode(struct inode *inode, int wait)
563 struct btrfs_root *root = btrfs_sb(inode->i_sb);
564 struct btrfs_trans_handle *trans;
567 mutex_lock(&root->fs_info->fs_mutex);
568 trans = btrfs_start_transaction(root, 1);
569 ret = btrfs_update_inode(trans, root, inode);
571 btrfs_commit_transaction(trans, root);
573 btrfs_end_transaction(trans, root);
574 mutex_unlock(&root->fs_info->fs_mutex);
578 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
579 struct inode *dir, int mode)
582 struct btrfs_inode_item inode_item;
583 struct btrfs_root *root = btrfs_sb(dir->i_sb);
584 struct btrfs_key key;
588 inode = new_inode(dir->i_sb);
590 return ERR_PTR(-ENOMEM);
592 ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
595 inode->i_uid = current->fsuid;
596 inode->i_gid = current->fsgid;
597 inode->i_mode = mode;
598 inode->i_ino = objectid;
600 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
601 fill_inode_item(&inode_item, inode);
603 key.objectid = objectid;
606 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
607 ret = btrfs_insert_inode_map(trans, root, objectid, &key);
610 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
613 insert_inode_hash(inode);
617 static int btrfs_add_link(struct btrfs_trans_handle *trans,
618 struct dentry *dentry, struct inode *inode)
621 ret = btrfs_insert_dir_item(trans, btrfs_sb(inode->i_sb),
622 dentry->d_name.name, dentry->d_name.len,
623 dentry->d_parent->d_inode->i_ino,
626 dentry->d_parent->d_inode->i_size += dentry->d_name.len;
627 ret = btrfs_update_inode(trans, btrfs_sb(inode->i_sb),
628 dentry->d_parent->d_inode);
634 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
635 struct dentry *dentry, struct inode *inode)
637 int err = btrfs_add_link(trans, dentry, inode);
639 d_instantiate(dentry, inode);
645 static int btrfs_create(struct inode *dir, struct dentry *dentry,
646 int mode, struct nameidata *nd)
648 struct btrfs_trans_handle *trans;
649 struct btrfs_root *root = btrfs_sb(dir->i_sb);
654 mutex_lock(&root->fs_info->fs_mutex);
655 trans = btrfs_start_transaction(root, 1);
656 inode = btrfs_new_inode(trans, dir, mode);
657 err = PTR_ERR(inode);
660 // FIXME mark the inode dirty
661 err = btrfs_add_nondir(trans, dentry, inode);
665 inode->i_mapping->a_ops = &btrfs_aops;
666 inode->i_fop = &btrfs_file_operations;
667 inode->i_op = &btrfs_file_inode_operations;
669 dir->i_sb->s_dirt = 1;
670 btrfs_end_transaction(trans, root);
672 mutex_unlock(&root->fs_info->fs_mutex);
674 inode_dec_link_count(inode);
680 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
681 struct inode *inode, struct inode *dir)
683 struct btrfs_root *root = btrfs_sb(inode->i_sb);
689 ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
693 ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
698 ret = btrfs_update_inode(trans, root, inode);
703 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
706 struct btrfs_trans_handle *trans;
707 struct btrfs_root *root = btrfs_sb(dir->i_sb);
711 mutex_lock(&root->fs_info->fs_mutex);
712 trans = btrfs_start_transaction(root, 1);
714 err = PTR_ERR(trans);
717 inode = btrfs_new_inode(trans, dir, S_IFDIR | mode);
719 err = PTR_ERR(inode);
723 inode->i_op = &btrfs_dir_inode_operations;
724 inode->i_fop = &btrfs_dir_file_operations;
726 err = btrfs_make_empty_dir(trans, inode, dir);
729 err = btrfs_add_link(trans, dentry, inode);
732 d_instantiate(dentry, inode);
736 btrfs_end_transaction(trans, root);
738 mutex_unlock(&root->fs_info->fs_mutex);
744 static int btrfs_sync_fs(struct super_block *sb, int wait)
746 struct btrfs_trans_handle *trans;
747 struct btrfs_root *root;
753 filemap_flush(root->fs_info->btree_inode->i_mapping);
756 filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
758 mutex_lock(&root->fs_info->fs_mutex);
759 trans = btrfs_start_transaction(root, 1);
760 ret = btrfs_commit_transaction(trans, root);
763 printk("btrfs sync_fs\n");
764 mutex_unlock(&root->fs_info->fs_mutex);
768 static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
769 struct buffer_head *result, int create)
774 u64 extent_start = 0;
776 u64 objectid = inode->i_ino;
777 struct btrfs_path path;
778 struct btrfs_root *root = btrfs_sb(inode->i_sb);
779 struct btrfs_trans_handle *trans = NULL;
780 struct btrfs_file_extent_item *item;
781 struct btrfs_leaf *leaf;
782 struct btrfs_disk_key *found_key;
784 btrfs_init_path(&path);
786 trans = btrfs_start_transaction(root, 1);
789 ret = btrfs_lookup_file_extent(trans, root, &path,
791 iblock << inode->i_blkbits, 0);
793 btrfs_release_path(root, &path);
799 if (path.slots[0] == 0) {
800 btrfs_release_path(root, &path);
806 item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
807 struct btrfs_file_extent_item);
808 leaf = btrfs_buffer_leaf(path.nodes[0]);
809 blocknr = btrfs_file_extent_disk_blocknr(item);
810 blocknr += btrfs_file_extent_offset(item);
812 /* exact match found, use it */
815 map_bh(result, inode->i_sb, blocknr);
816 btrfs_release_path(root, &path);
820 /* are we inside the extent that was found? */
821 found_key = &leaf->items[path.slots[0]].key;
822 if (btrfs_disk_key_objectid(found_key) != objectid ||
823 btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) {
826 btrfs_release_path(root, &path);
830 extent_start = btrfs_disk_key_offset(&leaf->items[path.slots[0]].key);
831 extent_start = extent_start >> inode->i_blkbits;
832 extent_start += btrfs_file_extent_offset(item);
833 extent_end = extent_start + btrfs_file_extent_num_blocks(item);
834 btrfs_release_path(root, &path);
835 if (iblock >= extent_start && iblock < extent_end) {
837 map_bh(result, inode->i_sb, blocknr + iblock - extent_start);
841 /* ok, create a new extent */
846 ret = btrfs_alloc_file_extent(trans, root, objectid,
847 iblock << inode->i_blkbits,
848 1, extent_end, &blocknr);
853 inode->i_blocks += inode->i_sb->s_blocksize >> 9;
854 set_buffer_new(result);
855 map_bh(result, inode->i_sb, blocknr);
859 btrfs_end_transaction(trans, root);
863 static int btrfs_get_block(struct inode *inode, sector_t iblock,
864 struct buffer_head *result, int create)
867 struct btrfs_root *root = btrfs_sb(inode->i_sb);
868 mutex_lock(&root->fs_info->fs_mutex);
869 err = btrfs_get_block_lock(inode, iblock, result, create);
870 mutex_unlock(&root->fs_info->fs_mutex);
874 static int btrfs_prepare_write(struct file *file, struct page *page,
875 unsigned from, unsigned to)
878 return nobh_prepare_write(page, from, to, btrfs_get_block);
880 static int btrfs_commit_write(struct file *file, struct page *page,
881 unsigned from, unsigned to)
884 return nobh_commit_write(file, page, from, to);
887 static void btrfs_write_super(struct super_block *sb)
889 btrfs_sync_fs(sb, 1);
892 static int btrfs_readpage(struct file *file, struct page *page)
894 return mpage_readpage(page, btrfs_get_block);
897 static int btrfs_readpages(struct file *file, struct address_space *mapping,
898 struct list_head *pages, unsigned nr_pages)
900 return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block);
903 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
905 return nobh_writepage(page, btrfs_get_block, wbc);
908 static void btrfs_truncate(struct inode *inode)
910 struct btrfs_root *root = btrfs_sb(inode->i_sb);
912 struct btrfs_trans_handle *trans;
914 if (!S_ISREG(inode->i_mode))
916 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
919 nobh_truncate_page(inode->i_mapping, inode->i_size);
921 /* FIXME, add redo link to tree so we don't leak on crash */
922 mutex_lock(&root->fs_info->fs_mutex);
923 trans = btrfs_start_transaction(root, 1);
924 ret = btrfs_truncate_in_trans(trans, root, inode);
926 ret = btrfs_end_transaction(trans, root);
928 mutex_unlock(&root->fs_info->fs_mutex);
929 mark_inode_dirty(inode);
932 static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
933 struct page **prepared_pages,
934 const char __user * buf)
938 int offset = pos & (PAGE_CACHE_SIZE - 1);
940 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
941 size_t count = min_t(size_t,
942 PAGE_CACHE_SIZE - offset, write_bytes);
943 struct page *page = prepared_pages[i];
944 fault_in_pages_readable(buf, count);
946 /* Copy data from userspace to the current page */
948 page_fault = __copy_from_user(page_address(page) + offset,
950 /* Flush processor's dcache for this page */
951 flush_dcache_page(page);
954 write_bytes -= count;
959 return page_fault ? -EFAULT : 0;
962 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
965 for (i = 0; i < num_pages; i++) {
968 unlock_page(pages[i]);
969 mark_page_accessed(pages[i]);
970 page_cache_release(pages[i]);
973 static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
974 struct btrfs_root *root,
986 struct inode *inode = file->f_path.dentry->d_inode;
988 for (i = 0; i < num_pages; i++) {
989 offset = pos & (PAGE_CACHE_SIZE -1);
990 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
991 /* FIXME, one block at a time */
993 mutex_lock(&root->fs_info->fs_mutex);
994 trans = btrfs_start_transaction(root, 1);
995 btrfs_csum_file_block(trans, root, inode->i_ino,
996 pages[i]->index << PAGE_CACHE_SHIFT,
997 kmap(pages[i]), PAGE_CACHE_SIZE);
999 SetPageChecked(pages[i]);
1000 ret = btrfs_end_transaction(trans, root);
1002 mutex_unlock(&root->fs_info->fs_mutex);
1004 ret = nobh_commit_write(file, pages[i], offset,
1005 offset + this_write);
1011 WARN_ON(this_write > write_bytes);
1012 write_bytes -= this_write;
1018 static int prepare_pages(struct btrfs_trans_handle *trans,
1019 struct btrfs_root *root,
1021 struct page **pages,
1027 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1028 struct inode *inode = file->f_path.dentry->d_inode;
1033 loff_t isize = i_size_read(inode);
1035 memset(pages, 0, num_pages * sizeof(struct page *));
1037 for (i = 0; i < num_pages; i++) {
1038 pages[i] = grab_cache_page(inode->i_mapping, index + i);
1041 goto failed_release;
1043 offset = pos & (PAGE_CACHE_SIZE -1);
1044 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
1045 ret = nobh_prepare_write(pages[i], offset,
1046 offset + this_write,
1051 goto failed_truncate;
1053 WARN_ON(this_write > write_bytes);
1054 write_bytes -= this_write;
1059 btrfs_drop_pages(pages, num_pages);
1063 btrfs_drop_pages(pages, num_pages);
1065 vmtruncate(inode, isize);
1069 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
1070 size_t count, loff_t *ppos)
1073 size_t num_written = 0;
1076 struct inode *inode = file->f_path.dentry->d_inode;
1077 struct btrfs_root *root = btrfs_sb(inode->i_sb);
1078 struct page *pages[1];
1080 if (file->f_flags & O_DIRECT)
1084 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1085 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1086 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1091 err = remove_suid(file->f_path.dentry);
1094 file_update_time(file);
1095 mutex_lock(&inode->i_mutex);
1097 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1098 size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
1099 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
1101 ret = prepare_pages(NULL, root, file, pages, num_pages,
1104 ret = btrfs_copy_from_user(pos, num_pages,
1105 write_bytes, pages, buf);
1108 ret = dirty_and_release_pages(NULL, root, file, pages,
1109 num_pages, pos, write_bytes);
1111 btrfs_drop_pages(pages, num_pages);
1114 count -= write_bytes;
1116 num_written += write_bytes;
1118 balance_dirty_pages_ratelimited(inode->i_mapping);
1121 mutex_unlock(&inode->i_mutex);
1124 current->backing_dev_info = NULL;
1125 return num_written ? num_written : err;
1128 static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
1129 unsigned long offset, unsigned long size)
1132 unsigned long left, count = desc->count;
1137 if (!PageChecked(page)) {
1138 /* FIXME, do it per block */
1139 struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
1140 int ret = btrfs_csum_verify_file_block(root,
1141 page->mapping->host->i_ino,
1142 page->index << PAGE_CACHE_SHIFT,
1143 kmap(page), PAGE_CACHE_SIZE);
1145 printk("failed to verify ino %lu page %lu\n",
1146 page->mapping->host->i_ino,
1148 memset(page_address(page), 0, PAGE_CACHE_SIZE);
1150 SetPageChecked(page);
1154 * Faults on the destination of a read are common, so do it before
1157 if (!fault_in_pages_writeable(desc->arg.buf, size)) {
1158 kaddr = kmap_atomic(page, KM_USER0);
1159 left = __copy_to_user_inatomic(desc->arg.buf,
1160 kaddr + offset, size);
1161 kunmap_atomic(kaddr, KM_USER0);
1166 /* Do it the slow way */
1168 left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
1173 desc->error = -EFAULT;
1176 desc->count = count - size;
1177 desc->written += size;
1178 desc->arg.buf += size;
1183 * btrfs_file_aio_read - filesystem read routine
1184 * @iocb: kernel I/O control block
1185 * @iov: io vector request
1186 * @nr_segs: number of segments in the iovec
1187 * @pos: current file position
1189 static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
1190 unsigned long nr_segs, loff_t pos)
1192 struct file *filp = iocb->ki_filp;
1196 loff_t *ppos = &iocb->ki_pos;
1199 for (seg = 0; seg < nr_segs; seg++) {
1200 const struct iovec *iv = &iov[seg];
1203 * If any segment has a negative length, or the cumulative
1204 * length ever wraps negative then return -EINVAL.
1206 count += iv->iov_len;
1207 if (unlikely((ssize_t)(count|iv->iov_len) < 0))
1209 if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
1214 count -= iv->iov_len; /* This segment is no good */
1219 for (seg = 0; seg < nr_segs; seg++) {
1220 read_descriptor_t desc;
1223 desc.arg.buf = iov[seg].iov_base;
1224 desc.count = iov[seg].iov_len;
1225 if (desc.count == 0)
1228 do_generic_file_read(filp, ppos, &desc,
1230 retval += desc.written;
1232 retval = retval ?: desc.error;
1240 static int btrfs_get_sb(struct file_system_type *fs_type,
1241 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1243 return get_sb_bdev(fs_type, flags, dev_name, data,
1244 btrfs_fill_super, mnt);
1247 static struct file_system_type btrfs_fs_type = {
1248 .owner = THIS_MODULE,
1250 .get_sb = btrfs_get_sb,
1251 .kill_sb = kill_block_super,
1252 .fs_flags = FS_REQUIRES_DEV,
1255 static struct super_operations btrfs_super_ops = {
1256 .statfs = simple_statfs,
1257 .delete_inode = btrfs_delete_inode,
1258 .put_super = btrfs_put_super,
1259 .read_inode = btrfs_read_locked_inode,
1260 .write_super = btrfs_write_super,
1261 .sync_fs = btrfs_sync_fs,
1262 .write_inode = btrfs_write_inode,
1265 static struct inode_operations btrfs_dir_inode_operations = {
1266 .lookup = btrfs_lookup,
1267 .create = btrfs_create,
1268 .unlink = btrfs_unlink,
1269 .mkdir = btrfs_mkdir,
1270 .rmdir = btrfs_rmdir,
1273 static struct file_operations btrfs_dir_file_operations = {
1274 .llseek = generic_file_llseek,
1275 .read = generic_read_dir,
1276 .readdir = btrfs_readdir,
1279 static struct address_space_operations btrfs_aops = {
1280 .readpage = btrfs_readpage,
1281 .readpages = btrfs_readpages,
1282 .writepage = btrfs_writepage,
1283 .sync_page = block_sync_page,
1284 .prepare_write = btrfs_prepare_write,
1285 .commit_write = btrfs_commit_write,
1288 static struct inode_operations btrfs_file_inode_operations = {
1289 .truncate = btrfs_truncate,
1292 static struct file_operations btrfs_file_operations = {
1293 .llseek = generic_file_llseek,
1294 .read = do_sync_read,
1295 .aio_read = btrfs_file_aio_read,
1296 .write = btrfs_file_write,
1297 .mmap = generic_file_mmap,
1298 .open = generic_file_open,
1301 static int __init init_btrfs_fs(void)
1303 printk("btrfs loaded!\n");
1304 return register_filesystem(&btrfs_fs_type);
1307 static void __exit exit_btrfs_fs(void)
1309 unregister_filesystem(&btrfs_fs_type);
1310 printk("btrfs unloaded\n");
1313 module_init(init_btrfs_fs)
1314 module_exit(exit_btrfs_fs)
1316 MODULE_LICENSE("GPL");