diff options
Diffstat (limited to 'fs/btrfs/inode.c')
| -rw-r--r-- | fs/btrfs/inode.c | 5035 |
1 files changed, 5035 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c new file mode 100644 index 0000000..8adfe05 --- /dev/null +++ b/fs/btrfs/inode.c @@ -0,0 +1,5035 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <linux/kernel.h> +#include <linux/bio.h> +#include <linux/buffer_head.h> +#include <linux/file.h> +#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> +#include <linux/mpage.h> +#include <linux/swap.h> +#include <linux/writeback.h> +#include <linux/statfs.h> +#include <linux/compat.h> +#include <linux/bit_spinlock.h> +#include <linux/version.h> +#include <linux/xattr.h> +#include <linux/posix_acl.h> +#include <linux/falloc.h> +#include "compat.h" +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "ioctl.h" +#include "print-tree.h" +#include "volumes.h" +#include "ordered-data.h" +#include "xattr.h" +#include "tree-log.h" +#include "ref-cache.h" +#include "compression.h" + +struct btrfs_iget_args { + u64 ino; + struct btrfs_root *root; +}; + +static struct inode_operations btrfs_dir_inode_operations; +static struct inode_operations btrfs_symlink_inode_operations; +static struct inode_operations btrfs_dir_ro_inode_operations; +static struct inode_operations btrfs_special_inode_operations; +static struct inode_operations btrfs_file_inode_operations; +static struct address_space_operations btrfs_aops; +static struct address_space_operations btrfs_symlink_aops; +static struct file_operations btrfs_dir_file_operations; +static struct extent_io_ops btrfs_extent_io_ops; + +static struct kmem_cache *btrfs_inode_cachep; +struct kmem_cache *btrfs_trans_handle_cachep; +struct kmem_cache *btrfs_transaction_cachep; +struct kmem_cache *btrfs_bit_radix_cachep; +struct kmem_cache *btrfs_path_cachep; + +#define S_SHIFT 12 +static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { + [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, + [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, + [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, + [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, + [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, + [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, + [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, +}; + +static void btrfs_truncate(struct inode *inode); +static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end); +static noinline int cow_file_range(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written, int unlock); + +/* + * a very lame attempt at stopping writes when the FS is 85% full. There + * are countless ways this is incorrect, but it is better than nothing. + */ +int btrfs_check_free_space(struct btrfs_root *root, u64 num_required, + int for_del) +{ + u64 total; + u64 used; + u64 thresh; + int ret = 0; + + spin_lock(&root->fs_info->delalloc_lock); + total = btrfs_super_total_bytes(&root->fs_info->super_copy); + used = btrfs_super_bytes_used(&root->fs_info->super_copy); + if (for_del) + thresh = total * 90; + else + thresh = total * 85; + + do_div(thresh, 100); + + if (used + root->fs_info->delalloc_bytes + num_required > thresh) + ret = -ENOSPC; + spin_unlock(&root->fs_info->delalloc_lock); + return ret; +} + +/* + * this does all the hard work for inserting an inline extent into + * the btree. The caller should have done a btrfs_drop_extents so that + * no overlapping inline items exist in the btree + */ +static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + u64 start, size_t size, size_t compressed_size, + struct page **compressed_pages) +{ + struct btrfs_key key; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct page *page = NULL; + char *kaddr; + unsigned long ptr; + struct btrfs_file_extent_item *ei; + int err = 0; + int ret; + size_t cur_size = size; + size_t datasize; + unsigned long offset; + int use_compress = 0; + + if (compressed_size && compressed_pages) { + use_compress = 1; + cur_size = compressed_size; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + btrfs_set_trans_block_group(trans, inode); + + key.objectid = inode->i_ino; + key.offset = start; + btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); + datasize = btrfs_file_extent_calc_inline_size(cur_size); + + inode_add_bytes(inode, size); + ret = btrfs_insert_empty_item(trans, root, path, &key, + datasize); + BUG_ON(ret); + if (ret) { + err = ret; + goto fail; + } + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, ei, trans->transid); + btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); + btrfs_set_file_extent_encryption(leaf, ei, 0); + btrfs_set_file_extent_other_encoding(leaf, ei, 0); + btrfs_set_file_extent_ram_bytes(leaf, ei, size); + ptr = btrfs_file_extent_inline_start(ei); + + if (use_compress) { + struct page *cpage; + int i = 0; + while (compressed_size > 0) { + cpage = compressed_pages[i]; + cur_size = min_t(unsigned long, compressed_size, + PAGE_CACHE_SIZE); + + kaddr = kmap(cpage); + write_extent_buffer(leaf, kaddr, ptr, cur_size); + kunmap(cpage); + + i++; + ptr += cur_size; + compressed_size -= cur_size; + } + btrfs_set_file_extent_compression(leaf, ei, + BTRFS_COMPRESS_ZLIB); + } else { + page = find_get_page(inode->i_mapping, + start >> PAGE_CACHE_SHIFT); + btrfs_set_file_extent_compression(leaf, ei, 0); + kaddr = kmap_atomic(page, KM_USER0); + offset = start & (PAGE_CACHE_SIZE - 1); + write_extent_buffer(leaf, kaddr + offset, ptr, size); + kunmap_atomic(kaddr, KM_USER0); + page_cache_release(page); + } + btrfs_mark_buffer_dirty(leaf); + btrfs_free_path(path); + + BTRFS_I(inode)->disk_i_size = inode->i_size; + btrfs_update_inode(trans, root, inode); + return 0; +fail: + btrfs_free_path(path); + return err; +} + + +/* + * conditionally insert an inline extent into the file. This + * does the checks required to make sure the data is small enough + * to fit as an inline extent. + */ +static int cow_file_range_inline(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, u64 start, u64 end, + size_t compressed_size, + struct page **compressed_pages) +{ + u64 isize = i_size_read(inode); + u64 actual_end = min(end + 1, isize); + u64 inline_len = actual_end - start; + u64 aligned_end = (end + root->sectorsize - 1) & + ~((u64)root->sectorsize - 1); + u64 hint_byte; + u64 data_len = inline_len; + int ret; + + if (compressed_size) + data_len = compressed_size; + + if (start > 0 || + actual_end >= PAGE_CACHE_SIZE || + data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || + (!compressed_size && + (actual_end & (root->sectorsize - 1)) == 0) || + end + 1 < isize || + data_len > root->fs_info->max_inline) { + return 1; + } + + ret = btrfs_drop_extents(trans, root, inode, start, + aligned_end, start, &hint_byte); + BUG_ON(ret); + + if (isize > actual_end) + inline_len = min_t(u64, isize, actual_end); + ret = insert_inline_extent(trans, root, inode, start, + inline_len, compressed_size, + compressed_pages); + BUG_ON(ret); + btrfs_drop_extent_cache(inode, start, aligned_end, 0); + return 0; +} + +struct async_extent { + u64 start; + u64 ram_size; + u64 compressed_size; + struct page **pages; + unsigned long nr_pages; + struct list_head list; +}; + +struct async_cow { + struct inode *inode; + struct btrfs_root *root; + struct page *locked_page; + u64 start; + u64 end; + struct list_head extents; + struct btrfs_work work; +}; + +static noinline int add_async_extent(struct async_cow *cow, + u64 start, u64 ram_size, + u64 compressed_size, + struct page **pages, + unsigned long nr_pages) +{ + struct async_extent *async_extent; + + async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); + async_extent->start = start; + async_extent->ram_size = ram_size; + async_extent->compressed_size = compressed_size; + async_extent->pages = pages; + async_extent->nr_pages = nr_pages; + list_add_tail(&async_extent->list, &cow->extents); + return 0; +} + +/* + * we create compressed extents in two phases. The first + * phase compresses a range of pages that have already been + * locked (both pages and state bits are locked). + * + * This is done inside an ordered work queue, and the compression + * is spread across many cpus. The actual IO submission is step + * two, and the ordered work queue takes care of making sure that + * happens in the same order things were put onto the queue by + * writepages and friends. + * + * If this code finds it can't get good compression, it puts an + * entry onto the work queue to write the uncompressed bytes. This + * makes sure that both compressed inodes and uncompressed inodes + * are written in the same order that pdflush sent them down. + */ +static noinline int compress_file_range(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, + struct async_cow *async_cow, + int *num_added) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + u64 num_bytes; + u64 orig_start; + u64 disk_num_bytes; + u64 blocksize = root->sectorsize; + u64 actual_end; + u64 isize = i_size_read(inode); + int ret = 0; + struct page **pages = NULL; + unsigned long nr_pages; + unsigned long nr_pages_ret = 0; + unsigned long total_compressed = 0; + unsigned long total_in = 0; + unsigned long max_compressed = 128 * 1024; + unsigned long max_uncompressed = 128 * 1024; + int i; + int will_compress; + + orig_start = start; + + actual_end = min_t(u64, isize, end + 1); +again: + will_compress = 0; + nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; + nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); + + total_compressed = actual_end - start; + + /* we want to make sure that amount of ram required to uncompress + * an extent is reasonable, so we limit the total size in ram + * of a compressed extent to 128k. This is a crucial number + * because it also controls how easily we can spread reads across + * cpus for decompression. + * + * We also want to make sure the amount of IO required to do + * a random read is reasonably small, so we limit the size of + * a compressed extent to 128k. + */ + total_compressed = min(total_compressed, max_uncompressed); + num_bytes = (end - start + blocksize) & ~(blocksize - 1); + num_bytes = max(blocksize, num_bytes); + disk_num_bytes = num_bytes; + total_in = 0; + ret = 0; + + /* + * we do compression for mount -o compress and when the + * inode has not been flagged as nocompress. This flag can + * change at any time if we discover bad compression ratios. + */ + if (!btrfs_test_flag(inode, NOCOMPRESS) && + btrfs_test_opt(root, COMPRESS)) { + WARN_ON(pages); + pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); + + ret = btrfs_zlib_compress_pages(inode->i_mapping, start, + total_compressed, pages, + nr_pages, &nr_pages_ret, + &total_in, + &total_compressed, + max_compressed); + + if (!ret) { + unsigned long offset = total_compressed & + (PAGE_CACHE_SIZE - 1); + struct page *page = pages[nr_pages_ret - 1]; + char *kaddr; + + /* zero the tail end of the last page, we might be + * sending it down to disk + */ + if (offset) { + kaddr = kmap_atomic(page, KM_USER0); + memset(kaddr + offset, 0, + PAGE_CACHE_SIZE - offset); + kunmap_atomic(kaddr, KM_USER0); + } + will_compress = 1; + } + } + if (start == 0) { + trans = btrfs_join_transaction(root, 1); + BUG_ON(!trans); + btrfs_set_trans_block_group(trans, inode); + + /* lets try to make an inline extent */ + if (ret || total_in < (actual_end - start)) { + /* we didn't compress the entire range, try + * to make an uncompressed inline extent. + */ + ret = cow_file_range_inline(trans, root, inode, + start, end, 0, NULL); + } else { + /* try making a compressed inline extent */ + ret = cow_file_range_inline(trans, root, inode, + start, end, + total_compressed, pages); + } + btrfs_end_transaction(trans, root); + if (ret == 0) { + /* + * inline extent creation worked, we don't need + * to create any more async work items. Unlock + * and free up our temp pages. + */ + extent_clear_unlock_delalloc(inode, + &BTRFS_I(inode)->io_tree, + start, end, NULL, 1, 0, + 0, 1, 1, 1); + ret = 0; + goto free_pages_out; + } + } + + if (will_compress) { + /* + * we aren't doing an inline extent round the compressed size + * up to a block size boundary so the allocator does sane + * things + */ + total_compressed = (total_compressed + blocksize - 1) & + ~(blocksize - 1); + + /* + * one last check to make sure the compression is really a + * win, compare the page count read with the blocks on disk + */ + total_in = (total_in + PAGE_CACHE_SIZE - 1) & + ~(PAGE_CACHE_SIZE - 1); + if (total_compressed >= total_in) { + will_compress = 0; + } else { + disk_num_bytes = total_compressed; + num_bytes = total_in; + } + } + if (!will_compress && pages) { + /* + * the compression code ran but failed to make things smaller, + * free any pages it allocated and our page pointer array + */ + for (i = 0; i < nr_pages_ret; i++) { + WARN_ON(pages[i]->mapping); + page_cache_release(pages[i]); + } + kfree(pages); + pages = NULL; + total_compressed = 0; + nr_pages_ret = 0; + + /* flag the file so we don't compress in the future */ + btrfs_set_flag(inode, NOCOMPRESS); + } + if (will_compress) { + *num_added += 1; + + /* the async work queues will take care of doing actual + * allocation on disk for these compressed pages, + * and will submit them to the elevator. + */ + add_async_extent(async_cow, start, num_bytes, + total_compressed, pages, nr_pages_ret); + + if (start + num_bytes < end && start + num_bytes < actual_end) { + start += num_bytes; + pages = NULL; + cond_resched(); + goto again; + } + } else { + /* + * No compression, but we still need to write the pages in + * the file we've been given so far. redirty the locked + * page if it corresponds to our extent and set things up + * for the async work queue to run cow_file_range to do + * the normal delalloc dance + */ + if (page_offset(locked_page) >= start && + page_offset(locked_page) <= end) { + __set_page_dirty_nobuffers(locked_page); + /* unlocked later on in the async handlers */ + } + add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0); + *num_added += 1; + } + +out: + return 0; + +free_pages_out: + for (i = 0; i < nr_pages_ret; i++) { + WARN_ON(pages[i]->mapping); + page_cache_release(pages[i]); + } + kfree(pages); + + goto out; +} + +/* + * phase two of compressed writeback. This is the ordered portion + * of the code, which only gets called in the order the work was + * queued. We walk all the async extents created by compress_file_range + * and send them down to the disk. + */ +static noinline int submit_compressed_extents(struct inode *inode, + struct async_cow *async_cow) +{ + struct async_extent *async_extent; + u64 alloc_hint = 0; + struct btrfs_trans_handle *trans; + struct btrfs_key ins; + struct extent_map *em; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_io_tree *io_tree; + int ret; + + if (list_empty(&async_cow->extents)) + return 0; + + trans = btrfs_join_transaction(root, 1); + + while (!list_empty(&async_cow->extents)) { + async_extent = list_entry(async_cow->extents.next, + struct async_extent, list); + list_del(&async_extent->list); + + io_tree = &BTRFS_I(inode)->io_tree; + + /* did the compression code fall back to uncompressed IO? */ + if (!async_extent->pages) { + int page_started = 0; + unsigned long nr_written = 0; + + lock_extent(io_tree, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, GFP_NOFS); + + /* allocate blocks */ + cow_file_range(inode, async_cow->locked_page, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + &page_started, &nr_written, 0); + + /* + * if page_started, cow_file_range inserted an + * inline extent and took care of all the unlocking + * and IO for us. Otherwise, we need to submit + * all those pages down to the drive. + */ + if (!page_started) + extent_write_locked_range(io_tree, + inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + btrfs_get_extent, + WB_SYNC_ALL); + kfree(async_extent); + cond_resched(); + continue; + } + + lock_extent(io_tree, async_extent->start, + async_extent->start + async_extent->ram_size - 1, + GFP_NOFS); + /* + * here we're doing allocation and writeback of the + * compressed pages + */ + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + + ret = btrfs_reserve_extent(trans, root, + async_extent->compressed_size, + async_extent->compressed_size, + 0, alloc_hint, + (u64)-1, &ins, 1); + BUG_ON(ret); + em = alloc_extent_map(GFP_NOFS); + em->start = async_extent->start; + em->len = async_extent->ram_size; + em->orig_start = em->start; + + em->block_start = ins.objectid; + em->block_len = ins.offset; + em->bdev = root->fs_info->fs_devices->latest_bdev; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + + while (1) { + spin_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + spin_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + } + + ret = btrfs_add_ordered_extent(inode, async_extent->start, + ins.objectid, + async_extent->ram_size, + ins.offset, + BTRFS_ORDERED_COMPRESSED); + BUG_ON(ret); + + btrfs_end_transaction(trans, root); + + /* + * clear dirty, set writeback and unlock the pages. + */ + extent_clear_unlock_delalloc(inode, + &BTRFS_I(inode)->io_tree, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + NULL, 1, 1, 0, 1, 1, 0); + + ret = btrfs_submit_compressed_write(inode, + async_extent->start, + async_extent->ram_size, + ins.objectid, + ins.offset, async_extent->pages, + async_extent->nr_pages); + + BUG_ON(ret); + trans = btrfs_join_transaction(root, 1); + alloc_hint = ins.objectid + ins.offset; + kfree(async_extent); + cond_resched(); + } + + btrfs_end_transaction(trans, root); + return 0; +} + +/* + * when extent_io.c finds a delayed allocation range in the file, + * the call backs end up in this code. The basic idea is to + * allocate extents on disk for the range, and create ordered data structs + * in ram to track those extents. + * + * locked_page is the page that writepage had locked already. We use + * it to make sure we don't do extra locks or unlocks. + * + * *page_started is set to one if we unlock locked_page and do everything + * required to start IO on it. It may be clean and already done with + * IO when we return. + */ +static noinline int cow_file_range(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written, + int unlock) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + u64 alloc_hint = 0; + u64 num_bytes; + unsigned long ram_size; + u64 disk_num_bytes; + u64 cur_alloc_size; + u64 blocksize = root->sectorsize; + u64 actual_end; + u64 isize = i_size_read(inode); + struct btrfs_key ins; + struct extent_map *em; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + int ret = 0; + + trans = btrfs_join_transaction(root, 1); + BUG_ON(!trans); + btrfs_set_trans_block_group(trans, inode); + + actual_end = min_t(u64, isize, end + 1); + + num_bytes = (end - start + blocksize) & ~(blocksize - 1); + num_bytes = max(blocksize, num_bytes); + disk_num_bytes = num_bytes; + ret = 0; + + if (start == 0) { + /* lets try to make an inline extent */ + ret = cow_file_range_inline(trans, root, inode, + start, end, 0, NULL); + if (ret == 0) { + extent_clear_unlock_delalloc(inode, + &BTRFS_I(inode)->io_tree, + start, end, NULL, 1, 1, + 1, 1, 1, 1); + *nr_written = *nr_written + + (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; + *page_started = 1; + ret = 0; + goto out; + } + } + + BUG_ON(disk_num_bytes > + btrfs_super_total_bytes(&root->fs_info->super_copy)); + + btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); + + while (disk_num_bytes > 0) { + cur_alloc_size = min(disk_num_bytes, root->fs_info->max_extent); + ret = btrfs_reserve_extent(trans, root, cur_alloc_size, + root->sectorsize, 0, alloc_hint, + (u64)-1, &ins, 1); + BUG_ON(ret); + + em = alloc_extent_map(GFP_NOFS); + em->start = start; + em->orig_start = em->start; + + ram_size = ins.offset; + em->len = ins.offset; + + em->block_start = ins.objectid; + em->block_len = ins.offset; + em->bdev = root->fs_info->fs_devices->latest_bdev; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + + while (1) { + spin_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + spin_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(inode, start, + start + ram_size - 1, 0); + } + + cur_alloc_size = ins.offset; + ret = btrfs_add_ordered_extent(inode, start, ins.objectid, + ram_size, cur_alloc_size, 0); + BUG_ON(ret); + + if (root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) { + ret = btrfs_reloc_clone_csums(inode, start, + cur_alloc_size); + BUG_ON(ret); + } + + if (disk_num_bytes < cur_alloc_size) + break; + + /* we're not doing compressed IO, don't unlock the first + * page (which the caller expects to stay locked), don't + * clear any dirty bits and don't set any writeback bits + */ + extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, + start, start + ram_size - 1, + locked_page, unlock, 1, + 1, 0, 0, 0); + disk_num_bytes -= cur_alloc_size; + num_bytes -= cur_alloc_size; + alloc_hint = ins.objectid + ins.offset; + start += cur_alloc_size; + } +out: + ret = 0; + btrfs_end_transaction(trans, root); + + return ret; +} + +/* + * work queue call back to started compression on a file and pages + */ +static noinline void async_cow_start(struct btrfs_work *work) +{ + struct async_cow *async_cow; + int num_added = 0; + async_cow = container_of(work, struct async_cow, work); + + compress_file_range(async_cow->inode, async_cow->locked_page, + async_cow->start, async_cow->end, async_cow, + &num_added); + if (num_added == 0) + async_cow->inode = NULL; +} + +/* + * work queue call back to submit previously compressed pages + */ +static noinline void async_cow_submit(struct btrfs_work *work) +{ + struct async_cow *async_cow; + struct btrfs_root *root; + unsigned long nr_pages; + + async_cow = container_of(work, struct async_cow, work); + + root = async_cow->root; + nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> + PAGE_CACHE_SHIFT; + + atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages); + + if (atomic_read(&root->fs_info->async_delalloc_pages) < + 5 * 1042 * 1024 && + waitqueue_active(&root->fs_info->async_submit_wait)) + wake_up(&root->fs_info->async_submit_wait); + + if (async_cow->inode) + submit_compressed_extents(async_cow->inode, async_cow); +} + +static noinline void async_cow_free(struct btrfs_work *work) +{ + struct async_cow *async_cow; + async_cow = container_of(work, struct async_cow, work); + kfree(async_cow); +} + +static int cow_file_range_async(struct inode *inode, struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written) +{ + struct async_cow *async_cow; + struct btrfs_root *root = BTRFS_I(inode)->root; + unsigned long nr_pages; + u64 cur_end; + int limit = 10 * 1024 * 1042; + + if (!btrfs_test_opt(root, COMPRESS)) { + return cow_file_range(inode, locked_page, start, end, + page_started, nr_written, 1); + } + + clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED | + EXTENT_DELALLOC, 1, 0, GFP_NOFS); + while (start < end) { + async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); + async_cow->inode = inode; + async_cow->root = root; + async_cow->locked_page = locked_page; + async_cow->start = start; + + if (btrfs_test_flag(inode, NOCOMPRESS)) + cur_end = end; + else + cur_end = min(end, start + 512 * 1024 - 1); + + async_cow->end = cur_end; + INIT_LIST_HEAD(&async_cow->extents); + + async_cow->work.func = async_cow_start; + async_cow->work.ordered_func = async_cow_submit; + async_cow->work.ordered_free = async_cow_free; + async_cow->work.flags = 0; + + nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> + PAGE_CACHE_SHIFT; + atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); + + btrfs_queue_worker(&root->fs_info->delalloc_workers, + &async_cow->work); + + if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->async_delalloc_pages) < + limit)); + } + + while (atomic_read(&root->fs_info->async_submit_draining) && + atomic_read(&root->fs_info->async_delalloc_pages)) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->async_delalloc_pages) == + 0)); + } + + *nr_written += nr_pages; + start = cur_end + 1; + } + *page_started = 1; + return 0; +} + +static noinline int csum_exist_in_range(struct btrfs_root *root, + u64 bytenr, u64 num_bytes) +{ + int ret; + struct btrfs_ordered_sum *sums; + LIST_HEAD(list); + + ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, + bytenr + num_bytes - 1, &list); + if (ret == 0 && list_empty(&list)) + return 0; + + while (!list_empty(&list)) { + sums = list_entry(list.next, struct btrfs_ordered_sum, list); + list_del(&sums->list); + kfree(sums); + } + return 1; +} + +/* + * when nowcow writeback call back. This checks for snapshots or COW copies + * of the extents that exist in the file, and COWs the file as required. + * + * If no cow copies or snapshots exist, we write directly to the existing + * blocks on disk + */ +static int run_delalloc_nocow(struct inode *inode, struct page *locked_page, + u64 start, u64 end, int *page_started, int force, + unsigned long *nr_written) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + struct extent_buffer *leaf; + struct btrfs_path *path; + struct btrfs_file_extent_item *fi; + struct btrfs_key found_key; + u64 cow_start; + u64 cur_offset; + u64 extent_end; + u64 disk_bytenr; + u64 num_bytes; + int extent_type; + int ret; + int type; + int nocow; + int check_prev = 1; + + path = btrfs_alloc_path(); + BUG_ON(!path); + trans = btrfs_join_transaction(root, 1); + BUG_ON(!trans); + + cow_start = (u64)-1; + cur_offset = start; + while (1) { + ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, + cur_offset, 0); + BUG_ON(ret < 0); + if (ret > 0 && path->slots[0] > 0 && check_prev) { + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, + path->slots[0] - 1); + if (found_key.objectid == inode->i_ino && + found_key.type == BTRFS_EXTENT_DATA_KEY) + path->slots[0]--; + } + check_prev = 0; +next_slot: + leaf = path->nodes[0]; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + BUG_ON(1); + if (ret > 0) + break; + leaf = path->nodes[0]; + } + + nocow = 0; + disk_bytenr = 0; + num_bytes = 0; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid > inode->i_ino || + found_key.type > BTRFS_EXTENT_DATA_KEY || + found_key.offset > end) + break; + + if (found_key.offset > cur_offset) { + extent_end = found_key.offset; + goto out_check; + } + + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + extent_end = found_key.offset + + btrfs_file_extent_num_bytes(leaf, fi); + if (extent_end <= start) { + path->slots[0]++; + goto next_slot; + } + if (disk_bytenr == 0) + goto out_check; + if (btrfs_file_extent_compression(leaf, fi) || + btrfs_file_extent_encryption(leaf, fi) || + btrfs_file_extent_other_encoding(leaf, fi)) + goto out_check; + if (extent_type == BTRFS_FILE_EXTENT_REG && !force) + goto out_check; + if (btrfs_extent_readonly(root, disk_bytenr)) + goto out_check; + if (btrfs_cross_ref_exist(trans, root, inode->i_ino, + disk_bytenr)) + goto out_check; + disk_bytenr += btrfs_file_extent_offset(leaf, fi); + disk_bytenr += cur_offset - found_key.offset; + num_bytes = min(end + 1, extent_end) - cur_offset; + /* + * force cow if csum exists in the range. + * this ensure that csum for a given extent are + * either valid or do not exist. + */ + if (csum_exist_in_range(root, disk_bytenr, num_bytes)) + goto out_check; + nocow = 1; + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + extent_end = found_key.offset + + btrfs_file_extent_inline_len(leaf, fi); + extent_end = ALIGN(extent_end, root->sectorsize); + } else { + BUG_ON(1); + } +out_check: + if (extent_end <= start) { + path->slots[0]++; + goto next_slot; + } + if (!nocow) { + if (cow_start == (u64)-1) + cow_start = cur_offset; + cur_offset = extent_end; + if (cur_offset > end) + break; + path->slots[0]++; + goto next_slot; + } + + btrfs_release_path(root, path); + if (cow_start != (u64)-1) { + ret = cow_file_range(inode, locked_page, cow_start, + found_key.offset - 1, page_started, + nr_written, 1); + BUG_ON(ret); + cow_start = (u64)-1; + } + + if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + struct extent_map *em; + struct extent_map_tree *em_tree; + em_tree = &BTRFS_I(inode)->extent_tree; + em = alloc_extent_map(GFP_NOFS); + em->start = cur_offset; + em->orig_start = em->start; + em->len = num_bytes; + em->block_len = num_bytes; + em->block_start = disk_bytenr; + em->bdev = root->fs_info->fs_devices->latest_bdev; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + while (1) { + spin_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + spin_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(inode, em->start, + em->start + em->len - 1, 0); + } + type = BTRFS_ORDERED_PREALLOC; + } else { + type = BTRFS_ORDERED_NOCOW; + } + + ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, + num_bytes, num_bytes, type); + BUG_ON(ret); + + extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, + cur_offset, cur_offset + num_bytes - 1, + locked_page, 1, 1, 1, 0, 0, 0); + cur_offset = extent_end; + if (cur_offset > end) + break; + } + btrfs_release_path(root, path); + + if (cur_offset <= end && cow_start == (u64)-1) + cow_start = cur_offset; + if (cow_start != (u64)-1) { + ret = cow_file_range(inode, locked_page, cow_start, end, + page_started, nr_written, 1); + BUG_ON(ret); + } + + ret = btrfs_end_transaction(trans, root); + BUG_ON(ret); + btrfs_free_path(path); + return 0; +} + +/* + * extent_io.c call back to do delayed allocation processing + */ +static int run_delalloc_range(struct inode *inode, struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written) +{ + int ret; + + if (btrfs_test_flag(inode, NODATACOW)) + ret = run_delalloc_nocow(inode, locked_page, start, end, + page_started, 1, nr_written); + else if (btrfs_test_flag(inode, PREALLOC)) + ret = run_delalloc_nocow(inode, locked_page, start, end, + page_started, 0, nr_written); + else + ret = cow_file_range_async(inode, locked_page, start, end, + page_started, nr_written); + + return ret; +} + +/* + * extent_io.c set_bit_hook, used to track delayed allocation + * bytes in this file, and to maintain the list of inodes that + * have pending delalloc work to be done. + */ +static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end, + unsigned long old, unsigned long bits) +{ + /* + * set_bit and clear bit hooks normally require _irqsave/restore + * but in this case, we are only testeing for the DELALLOC + * bit, which is only set or cleared with irqs on + */ + if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { + struct btrfs_root *root = BTRFS_I(inode)->root; + spin_lock(&root->fs_info->delalloc_lock); + BTRFS_I(inode)->delalloc_bytes += end - start + 1; + root->fs_info->delalloc_bytes += end - start + 1; + if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { + list_add_tail(&BTRFS_I(inode)->delalloc_inodes, + &root->fs_info->delalloc_inodes); + } + spin_unlock(&root->fs_info->delalloc_lock); + } + return 0; +} + +/* + * extent_io.c clear_bit_hook, see set_bit_hook for why + */ +static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end, + unsigned long old, unsigned long bits) +{ + /* + * set_bit and clear bit hooks normally require _irqsave/restore + * but in this case, we are only testeing for the DELALLOC + * bit, which is only set or cleared with irqs on + */ + if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { + struct btrfs_root *root = BTRFS_I(inode)->root; + + spin_lock(&root->fs_info->delalloc_lock); + if (end - start + 1 > root->fs_info->delalloc_bytes) { + printk(KERN_INFO "btrfs warning: delalloc account " + "%llu %llu\n", + (unsigned long long)end - start + 1, + (unsigned long long) + root->fs_info->delalloc_bytes); + root->fs_info->delalloc_bytes = 0; + BTRFS_I(inode)->delalloc_bytes = 0; + } else { + root->fs_info->delalloc_bytes -= end - start + 1; + BTRFS_I(inode)->delalloc_bytes -= end - start + 1; + } + if (BTRFS_I(inode)->delalloc_bytes == 0 && + !list_empty(&BTRFS_I(inode)->delalloc_inodes)) { + list_del_init(&BTRFS_I(inode)->delalloc_inodes); + } + spin_unlock(&root->fs_info->delalloc_lock); + } + return 0; +} + +/* + * extent_io.c merge_bio_hook, this must check the chunk tree to make sure + * we don't create bios that span stripes or chunks + */ +int btrfs_merge_bio_hook(struct page *page, unsigned long offset, + size_t size, struct bio *bio, + unsigned long bio_flags) +{ + struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; + struct btrfs_mapping_tree *map_tree; + u64 logical = (u64)bio->bi_sector << 9; + u64 length = 0; + u64 map_length; + int ret; + + if (bio_flags & EXTENT_BIO_COMPRESSED) + return 0; + + length = bio->bi_size; + map_tree = &root->fs_info->mapping_tree; + map_length = length; + ret = btrfs_map_block(map_tree, READ, logical, + &map_length, NULL, 0); + + if (map_length < length + size) + return 1; + return 0; +} + +/* + * in order to insert checksums into the metadata in large chunks, + * we wait until bio submission time. All the pages in the bio are + * checksummed and sums are attached onto the ordered extent record. + * + * At IO completion time the cums attached on the ordered extent record + * are inserted into the btree + */ +static int __btrfs_submit_bio_start(struct inode *inode, int rw, + struct bio *bio, int mirror_num, + unsigned long bio_flags) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + + ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); + BUG_ON(ret); + return 0; +} + +/* + * in order to insert checksums into the metadata in large chunks, + * we wait until bio submission time. All the pages in the bio are + * checksummed and sums are attached onto the ordered extent record. + * + * At IO completion time the cums attached on the ordered extent record + * are inserted into the btree + */ +static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, + int mirror_num, unsigned long bio_flags) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + return btrfs_map_bio(root, rw, bio, mirror_num, 1); +} + +/* + * extent_io.c submission hook. This does the right thing for csum calculation + * on write, or reading the csums from the tree before a read + */ +static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, + int mirror_num, unsigned long bio_flags) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + int skip_sum; + + skip_sum = btrfs_test_flag(inode, NODATASUM); + + ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); + BUG_ON(ret); + + if (!(rw & (1 << BIO_RW))) { + if (bio_flags & EXTENT_BIO_COMPRESSED) { + return btrfs_submit_compressed_read(inode, bio, + mirror_num, bio_flags); + } else if (!skip_sum) + btrfs_lookup_bio_sums(root, inode, bio, NULL); + goto mapit; + } else if (!skip_sum) { + /* csum items have already been cloned */ + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) + goto mapit; + /* we're doing a write, do the async checksumming */ + return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, + inode, rw, bio, mirror_num, + bio_flags, __btrfs_submit_bio_start, + __btrfs_submit_bio_done); + } + +mapit: + return btrfs_map_bio(root, rw, bio, mirror_num, 0); +} + +/* + * given a list of ordered sums record them in the inode. This happens + * at IO completion time based on sums calculated at bio submission time. + */ +static noinline int add_pending_csums(struct btrfs_trans_handle *trans, + struct inode *inode, u64 file_offset, + struct list_head *list) +{ + struct list_head *cur; + struct btrfs_ordered_sum *sum; + + btrfs_set_trans_block_group(trans, inode); + list_for_each(cur, list) { + sum = list_entry(cur, struct btrfs_ordered_sum, list); + btrfs_csum_file_blocks(trans, + BTRFS_I(inode)->root->fs_info->csum_root, sum); + } + return 0; +} + +int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end) +{ + if ((end & (PAGE_CACHE_SIZE - 1)) == 0) + WARN_ON(1); + return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, + GFP_NOFS); +} + +/* see btrfs_writepage_start_hook for details on why this is required */ +struct btrfs_writepage_fixup { + struct page *page; + struct btrfs_work work; +}; + +static void btrfs_writepage_fixup_worker(struct btrfs_work *work) +{ + struct btrfs_writepage_fixup *fixup; + struct btrfs_ordered_extent *ordered; + struct page *page; + struct inode *inode; + u64 page_start; + u64 page_end; + + fixup = container_of(work, struct btrfs_writepage_fixup, work); + page = fixup->page; +again: + lock_page(page); + if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { + ClearPageChecked(page); + goto out_page; + } + + inode = page->mapping->host; + page_start = page_offset(page); + page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; + + lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS); + + /* already ordered? We're done */ + if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, + EXTENT_ORDERED, 0)) { + goto out; + } + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent(&BTRFS_I(inode)->io_tree, page_start, + page_end, GFP_NOFS); + unlock_page(page); + btrfs_start_ordered_extent(inode, ordered, 1); + goto again; + } + + btrfs_set_extent_delalloc(inode, page_start, page_end); + ClearPageChecked(page); +out: + unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS); +out_page: + unlock_page(page); + page_cache_release(page); +} + +/* + * There are a few paths in the higher layers of the kernel that directly + * set the page dirty bit without asking the filesystem if it is a + * good idea. This causes problems because we want to make sure COW + * properly happens and the data=ordered rules are followed. + * + * In our case any range that doesn't have the ORDERED bit set + * hasn't been properly setup for IO. We kick off an async process + * to fix it up. The async helper will wait for ordered extents, set + * the delalloc bit and make it safe to write the page. + */ +static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) +{ + struct inode *inode = page->mapping->host; + struct btrfs_writepage_fixup *fixup; + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + + ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end, + EXTENT_ORDERED, 0); + if (ret) + return 0; + + if (PageChecked(page)) + return -EAGAIN; + + fixup = kzalloc(sizeof(*fixup), GFP_NOFS); + if (!fixup) + return -EAGAIN; + + SetPageChecked(page); + page_cache_get(page); + fixup->work.func = btrfs_writepage_fixup_worker; + fixup->page = page; + btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work); + return -EAGAIN; +} + +static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, + struct inode *inode, u64 file_pos, + u64 disk_bytenr, u64 disk_num_bytes, + u64 num_bytes, u64 ram_bytes, + u8 compression, u8 encryption, + u16 other_encoding, int extent_type) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_file_extent_item *fi; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key ins; + u64 hint; + int ret; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + ret = btrfs_drop_extents(trans, root, inode, file_pos, + file_pos + num_bytes, file_pos, &hint); + BUG_ON(ret); + + ins.objectid = inode->i_ino; + ins.offset = file_pos; + ins.type = BTRFS_EXTENT_DATA_KEY; + ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi)); + BUG_ON(ret); + leaf = path->nodes[0]; + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, fi, trans->transid); + btrfs_set_file_extent_type(leaf, fi, extent_type); + btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); + btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); + btrfs_set_file_extent_offset(leaf, fi, 0); + btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); + btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); + btrfs_set_file_extent_compression(leaf, fi, compression); + btrfs_set_file_extent_encryption(leaf, fi, encryption); + btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); + btrfs_mark_buffer_dirty(leaf); + + inode_add_bytes(inode, num_bytes); + btrfs_drop_extent_cache(inode, file_pos, file_pos + num_bytes - 1, 0); + + ins.objectid = disk_bytenr; + ins.offset = disk_num_bytes; + ins.type = BTRFS_EXTENT_ITEM_KEY; + ret = btrfs_alloc_reserved_extent(trans, root, leaf->start, + root->root_key.objectid, + trans->transid, inode->i_ino, &ins); + BUG_ON(ret); + + btrfs_free_path(path); + return 0; +} + +/* as ordered data IO finishes, this gets called so we can finish + * an ordered extent if the range of bytes in the file it covers are + * fully written. + */ +static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + struct btrfs_ordered_extent *ordered_extent; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + int compressed = 0; + int ret; + + ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1); + if (!ret) + return 0; + + trans = btrfs_join_transaction(root, 1); + + ordered_extent = btrfs_lookup_ordered_extent(inode, start); + BUG_ON(!ordered_extent); + if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) + goto nocow; + + lock_extent(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + ordered_extent->len - 1, + GFP_NOFS); + + if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) + compressed = 1; + if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { + BUG_ON(compressed); + ret = btrfs_mark_extent_written(trans, root, inode, + ordered_extent->file_offset, + ordered_extent->file_offset + + ordered_extent->len); + BUG_ON(ret); + } else { + ret = insert_reserved_file_extent(trans, inode, + ordered_extent->file_offset, + ordered_extent->start, + ordered_extent->disk_len, + ordered_extent->len, + ordered_extent->len, + compressed, 0, 0, + BTRFS_FILE_EXTENT_REG); + BUG_ON(ret); + } + unlock_extent(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + ordered_extent->len - 1, + GFP_NOFS); +nocow: + add_pending_csums(trans, inode, ordered_extent->file_offset, + &ordered_extent->list); + + mutex_lock(&BTRFS_I(inode)->extent_mutex); + btrfs_ordered_update_i_size(inode, ordered_extent); + btrfs_update_inode(trans, root, inode); + btrfs_remove_ordered_extent(inode, ordered_extent); + mutex_unlock(&BTRFS_I(inode)->extent_mutex); + + /* once for us */ + btrfs_put_ordered_extent(ordered_extent); + /* once for the tree */ + btrfs_put_ordered_extent(ordered_extent); + + btrfs_end_transaction(trans, root); + return 0; +} + +static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, + struct extent_state *state, int uptodate) +{ + return btrfs_finish_ordered_io(page->mapping->host, start, end); +} + +/* + * When IO fails, either with EIO or csum verification fails, we + * try other mirrors that might have a good copy of the data. This + * io_failure_record is used to record state as we go through all the + * mirrors. If another mirror has good data, the page is set up to date + * and things continue. If a good mirror can't be found, the original + * bio end_io callback is called to indicate things have failed. + */ +struct io_failure_record { + struct page *page; + u64 start; + u64 len; + u64 logical; + unsigned long bio_flags; + int last_mirror; +}; + +static int btrfs_io_failed_hook(struct bio *failed_bio, + struct page *page, u64 start, u64 end, + struct extent_state *state) +{ + struct io_failure_record *failrec = NULL; + u64 private; + struct extent_map *em; + struct inode *inode = page->mapping->host; + struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct bio *bio; + int num_copies; + int ret; + int rw; + u64 logical; + + ret = get_state_private(failure_tree, start, &private); + if (ret) { + failrec = kmalloc(sizeof(*failrec), GFP_NOFS); + if (!failrec) + return -ENOMEM; + failrec->start = start; + failrec->len = end - start + 1; + failrec->last_mirror = 0; + failrec->bio_flags = 0; + + spin_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, start, failrec->len); + if (em->start > start || em->start + em->len < start) { + free_extent_map(em); + em = NULL; + } + spin_unlock(&em_tree->lock); + + if (!em || IS_ERR(em)) { + kfree(failrec); + return -EIO; + } + logical = start - em->start; + logical = em->block_start + logical; + if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { + logical = em->block_start; + failrec->bio_flags = EXTENT_BIO_COMPRESSED; + } + failrec->logical = logical; + free_extent_map(em); + set_extent_bits(failure_tree, start, end, EXTENT_LOCKED | + EXTENT_DIRTY, GFP_NOFS); + set_state_private(failure_tree, start, + (u64)(unsigned long)failrec); + } else { + failrec = (struct io_failure_record *)(unsigned long)private; + } + num_copies = btrfs_num_copies( + &BTRFS_I(inode)->root->fs_info->mapping_tree, + failrec->logical, failrec->len); + failrec->last_mirror++; + if (!state) { + spin_lock(&BTRFS_I(inode)->io_tree.lock); + state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree, + failrec->start, + EXTENT_LOCKED); + if (state && state->start != failrec->start) + state = NULL; + spin_unlock(&BTRFS_I(inode)->io_tree.lock); + } + if (!state || failrec->last_mirror > num_copies) { + set_state_private(failure_tree, failrec->start, 0); + clear_extent_bits(failure_tree, failrec->start, + failrec->start + failrec->len - 1, + EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS); + kfree(failrec); + return -EIO; + } + bio = bio_alloc(GFP_NOFS, 1); + bio->bi_private = state; + bio->bi_end_io = failed_bio->bi_end_io; + bio->bi_sector = failrec->logical >> 9; + bio->bi_bdev = failed_bio->bi_bdev; + bio->bi_size = 0; + + bio_add_page(bio, page, failrec->len, start - page_offset(page)); + if (failed_bio->bi_rw & (1 << BIO_RW)) + rw = WRITE; + else + rw = READ; + + BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio, + failrec->last_mirror, + failrec->bio_flags); + return 0; +} + +/* + * each time an IO finishes, we do a fast check in the IO failure tree + * to see if we need to process or clean up an io_failure_record + */ +static int btrfs_clean_io_failures(struct inode *inode, u64 start) +{ + u64 private; + u64 private_failure; + struct io_failure_record *failure; + int ret; + + private = 0; + if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private, + (u64)-1, 1, EXTENT_DIRTY)) { + ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, + start, &private_failure); + if (ret == 0) { + failure = (struct io_failure_record *)(unsigned long) + private_failure; + set_state_private(&BTRFS_I(inode)->io_failure_tree, + failure->start, 0); + clear_extent_bits(&BTRFS_I(inode)->io_failure_tree, + failure->start, + failure->start + failure->len - 1, + EXTENT_DIRTY | EXTENT_LOCKED, + GFP_NOFS); + kfree(failure); + } + } + return 0; +} + +/* + * when reads are done, we need to check csums to verify the data is correct + * if there's a match, we allow the bio to finish. If not, we go through + * the io_failure_record routines to find good copies + */ +static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end, + struct extent_state *state) +{ + size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT); + struct inode *inode = page->mapping->host; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + char *kaddr; + u64 private = ~(u32)0; + int ret; + struct btrfs_root *root = BTRFS_I(inode)->root; + u32 csum = ~(u32)0; + + if (PageChecked(page)) { + ClearPageChecked(page); + goto good; + } + if (btrfs_test_flag(inode, NODATASUM)) + return 0; + + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && + test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1)) { + clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, + GFP_NOFS); + return 0; + } + + if (state && state->start == start) { + private = state->private; + ret = 0; + } else { + ret = get_state_private(io_tree, start, &private); + } + kaddr = kmap_atomic(page, KM_USER0); + if (ret) + goto zeroit; + + csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1); + btrfs_csum_final(csum, (char *)&csum); + if (csum != private) + goto zeroit; + + kunmap_atomic(kaddr, KM_USER0); +good: + /* if the io failure tree for this inode is non-empty, + * check to see if we've recovered from a failed IO + */ + btrfs_clean_io_failures(inode, start); + return 0; + +zeroit: + printk(KERN_INFO "btrfs csum failed ino %lu off %llu csum %u " + "private %llu\n", page->mapping->host->i_ino, + (unsigned long long)start, csum, + (unsigned long long)private); + memset(kaddr + offset, 1, end - start + 1); + flush_dcache_page(page); + kunmap_atomic(kaddr, KM_USER0); + if (private == 0) + return 0; + return -EIO; +} + +/* + * This creates an orphan entry for the given inode in case something goes + * wrong in the middle of an unlink/truncate. + */ +int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + + spin_lock(&root->list_lock); + + /* already on the orphan list, we're good */ + if (!list_empty(&BTRFS_I(inode)->i_orphan)) { + spin_unlock(&root->list_lock); + return 0; + } + + list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list); + + spin_unlock(&root->list_lock); + + /* + * insert an orphan item to track this unlinked/truncated file + */ + ret = btrfs_insert_orphan_item(trans, root, inode->i_ino); + + return ret; +} + +/* + * We have done the truncate/delete so we can go ahead and remove the orphan + * item for this particular inode. + */ +int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + + spin_lock(&root->list_lock); + + if (list_empty(&BTRFS_I(inode)->i_orphan)) { + spin_unlock(&root->list_lock); + return 0; + } + + list_del_init(&BTRFS_I(inode)->i_orphan); + if (!trans) { + spin_unlock(&root->list_lock); + return 0; + } + + spin_unlock(&root->list_lock); + + ret = btrfs_del_orphan_item(trans, root, inode->i_ino); + + return ret; +} + +/* + * this cleans up any orphans that may be left on the list from the last use + * of this root. + */ +void btrfs_orphan_cleanup(struct btrfs_root *root) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_item *item; + struct btrfs_key key, found_key; + struct btrfs_trans_handle *trans; + struct inode *inode; + int ret = 0, nr_unlink = 0, nr_truncate = 0; + + path = btrfs_alloc_path(); + if (!path) + return; + path->reada = -1; + + key.objectid = BTRFS_ORPHAN_OBJECTID; + btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); + key.offset = (u64)-1; + + + while (1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) { + printk(KERN_ERR "Error searching slot for orphan: %d" + "\n", ret); + break; + } + + /* + * if ret == 0 means we found what we were searching for, which + * is weird, but possible, so only screw with path if we didnt + * find the key and see if we have stuff that matches + */ + if (ret > 0) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + + /* pull out the item */ + leaf = path->nodes[0]; + item = btrfs_item_nr(leaf, path->slots[0]); + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + /* make sure the item matches what we want */ + if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) + break; + if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY) + break; + + /* release the path since we're done with it */ + btrfs_release_path(root, path); + + /* + * this is where we are basically btrfs_lookup, without the + * crossing root thing. we store the inode number in the + * offset of the orphan item. + */ + inode = btrfs_iget_locked(root->fs_info->sb, + found_key.offset, root); + if (!inode) + break; + + if (inode->i_state & I_NEW) { + BTRFS_I(inode)->root = root; + + /* have to set the location manually */ + BTRFS_I(inode)->location.objectid = inode->i_ino; + BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.offset = 0; + + btrfs_read_locked_inode(inode); + unlock_new_inode(inode); + } + + /* + * add this inode to the orphan list so btrfs_orphan_del does + * the proper thing when we hit it + */ + spin_lock(&root->list_lock); + list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list); + spin_unlock(&root->list_lock); + + /* + * if this is a bad inode, means we actually succeeded in + * removing the inode, but not the orphan record, which means + * we need to manually delete the orphan since iput will just + * do a destroy_inode + */ + if (is_bad_inode(inode)) { + trans = btrfs_start_transaction(root, 1); + btrfs_orphan_del(trans, inode); + btrfs_end_transaction(trans, root); + iput(inode); + continue; + } + + /* if we have links, this was a truncate, lets do that */ + if (inode->i_nlink) { + nr_truncate++; + btrfs_truncate(inode); + } else { + nr_unlink++; + } + + /* this will do delete_inode and everything for us */ + iput(inode); + } + + if (nr_unlink) + printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink); + if (nr_truncate) + printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate); + + btrfs_free_path(path); +} + +/* + * read an inode from the btree into the in-memory inode + */ +void btrfs_read_locked_inode(struct inode *inode) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_inode_item *inode_item; + struct btrfs_timespec *tspec; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key location; + u64 alloc_group_block; + u32 rdev; + int ret; + + path = btrfs_alloc_path(); + BUG_ON(!path); + memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); + + ret = btrfs_lookup_inode(NULL, root, path, &location, 0); + if (ret) + goto make_bad; + + leaf = path->nodes[0]; + inode_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_inode_item); + + inode->i_mode = btrfs_inode_mode(leaf, inode_item); + inode->i_nlink = btrfs_inode_nlink(leaf, inode_item); + inode->i_uid = btrfs_inode_uid(leaf, inode_item); + inode->i_gid = btrfs_inode_gid(leaf, inode_item); + btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); + + tspec = btrfs_inode_atime(inode_item); + inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec); + inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); + + tspec = btrfs_inode_mtime(inode_item); + inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec); + inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); + + tspec = btrfs_inode_ctime(inode_item); + inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec); + inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); + + inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); + BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); + BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item); + inode->i_generation = BTRFS_I(inode)->generation; + inode->i_rdev = 0; + rdev = btrfs_inode_rdev(leaf, inode_item); + + BTRFS_I(inode)->index_cnt = (u64)-1; + BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); + + alloc_group_block = btrfs_inode_block_group(leaf, inode_item); + BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0, + alloc_group_block, 0); + btrfs_free_path(path); + inode_item = NULL; + + switch (inode->i_mode & S_IFMT) { + case S_IFREG: + inode->i_mapping->a_ops = &btrfs_aops; + inode->i_mapping->backing_dev_info = &root->fs_info->bdi; + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + break; + case S_IFDIR: + inode->i_fop = &btrfs_dir_file_operations; + if (root == root->fs_info->tree_root) + inode->i_op = &btrfs_dir_ro_inode_operations; + else + inode->i_op = &btrfs_dir_inode_operations; + break; + case S_IFLNK: + inode->i_op = &btrfs_symlink_inode_operations; + inode->i_mapping->a_ops = &btrfs_symlink_aops; + inode->i_mapping->backing_dev_info = &root->fs_info->bdi; + break; + default: + init_special_inode(inode, inode->i_mode, rdev); + break; + } + return; + +make_bad: + btrfs_free_path(path); + make_bad_inode(inode); +} + +/* + * given a leaf and an inode, copy the inode fields into the leaf + */ +static void fill_inode_item(struct btrfs_trans_handle *trans, + struct extent_buffer *leaf, + struct btrfs_inode_item *item, + struct inode *inode) +{ + btrfs_set_inode_uid(leaf, item, inode->i_uid); + btrfs_set_inode_gid(leaf, item, inode->i_gid); + btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size); + btrfs_set_inode_mode(leaf, item, inode->i_mode); + btrfs_set_inode_nlink(leaf, item, inode->i_nlink); + + btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item), + inode->i_atime.tv_sec); + btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item), + inode->i_atime.tv_nsec); + + btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item), + inode->i_mtime.tv_sec); + btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item), + inode->i_mtime.tv_nsec); + + btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item), + inode->i_ctime.tv_sec); + btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item), + inode->i_ctime.tv_nsec); + + btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode)); + btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation); + btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence); + btrfs_set_inode_transid(leaf, item, trans->transid); + btrfs_set_inode_rdev(leaf, item, inode->i_rdev); + btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags); + btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group); +} + +/* + * copy everything in the in-memory inode into the btree. + */ +noinline 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; + struct extent_buffer *leaf; + int ret; + + path = btrfs_alloc_path(); + BUG_ON(!path); + ret = btrfs_lookup_inode(trans, root, path, + &BTRFS_I(inode)->location, 1); + if (ret) { + if (ret > 0) + ret = -ENOENT; + goto failed; + } + + leaf = path->nodes[0]; + inode_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_inode_item); + + fill_inode_item(trans, leaf, inode_item, inode); + btrfs_mark_buffer_dirty(leaf); + btrfs_set_inode_last_trans(trans, inode); + ret = 0; +failed: + btrfs_free_path(path); + return ret; +} + + +/* + * unlink helper that gets used here in inode.c and in the tree logging + * recovery code. It remove a link in a directory with a given name, and + * also drops the back refs in the inode to the directory + */ +int btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, struct inode *inode, + const char *name, int name_len) +{ + struct btrfs_path *path; + int ret = 0; + struct extent_buffer *leaf; + struct btrfs_dir_item *di; + struct btrfs_key key; + u64 index; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto err; + } + + di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino, + name, name_len, -1); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto err; + } + if (!di) { + ret = -ENOENT; + goto err; + } + leaf = path->nodes[0]; + btrfs_dir_item_key_to_cpu(leaf, di, &key); + ret = btrfs_delete_one_dir_name(trans, root, path, di); + if (ret) + goto err; + btrfs_release_path(root, path); + + ret = btrfs_del_inode_ref(trans, root, name, name_len, + inode->i_ino, + dir->i_ino, &index); + if (ret) { + printk(KERN_INFO "btrfs failed to delete reference to %.*s, " + "inode %lu parent %lu\n", name_len, name, + inode->i_ino, dir->i_ino); + goto err; + } + + di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, + index, name, name_len, -1); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto err; + } + if (!di) { + ret = -ENOENT; + goto err; + } + ret = btrfs_delete_one_dir_name(trans, root, path, di); + btrfs_release_path(root, path); + + ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, + inode, dir->i_ino); + BUG_ON(ret != 0 && ret != -ENOENT); + if (ret != -ENOENT) + BTRFS_I(dir)->log_dirty_trans = trans->transid; + + ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, + dir, index); + BUG_ON(ret); +err: + btrfs_free_path(path); + if (ret) + goto out; + + btrfs_i_size_write(dir, dir->i_size - name_len * 2); + inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; + btrfs_update_inode(trans, root, dir); + btrfs_drop_nlink(inode); + ret = btrfs_update_inode(trans, root, inode); + dir->i_sb->s_dirt = 1; +out: + return ret; +} + +static int btrfs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct btrfs_root *root; + struct btrfs_trans_handle *trans; + struct inode *inode = dentry->d_inode; + int ret; + unsigned long nr = 0; + + root = BTRFS_I(dir)->root; + + ret = btrfs_check_free_space(root, 1, 1); + if (ret) + goto fail; + + trans = btrfs_start_transaction(root, 1); + + btrfs_set_trans_block_group(trans, dir); + ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, + dentry->d_name.name, dentry->d_name.len); + + if (inode->i_nlink == 0) + ret = btrfs_orphan_add(trans, inode); + + nr = trans->blocks_used; + + btrfs_end_transaction_throttle(trans, root); +fail: + btrfs_btree_balance_dirty(root, nr); + return ret; +} + +static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + int err = 0; + int ret; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_trans_handle *trans; + unsigned long nr = 0; + + /* + * the FIRST_FREE_OBJECTID check makes sure we don't try to rmdir + * the root of a subvolume or snapshot + */ + if (inode->i_size > BTRFS_EMPTY_DIR_SIZE || + inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) { + return -ENOTEMPTY; + } + + ret = btrfs_check_free_space(root, 1, 1); + if (ret) + goto fail; + + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, dir); + + err = btrfs_orphan_add(trans, inode); + if (err) + goto fail_trans; + + /* now the directory is empty */ + err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, + dentry->d_name.name, dentry->d_name.len); + if (!err) + btrfs_i_size_write(inode, 0); + +fail_trans: + nr = trans->blocks_used; + ret = btrfs_end_transaction_throttle(trans, root); +fail: + btrfs_btree_balance_dirty(root, nr); + + if (ret && !err) + err = ret; + return err; +} + +#if 0 +/* + * when truncating bytes in a file, it is possible to avoid reading + * the leaves that contain only checksum items. This can be the + * majority of the IO required to delete a large file, but it must + * be done carefully. + * + * The keys in the level just above the leaves are checked to make sure + * the lowest key in a given leaf is a csum key, and starts at an offset + * after the new size. + * + * Then the key for the next leaf is checked to make sure it also has + * a checksum item for the same file. If it does, we know our target leaf + * contains only checksum items, and it can be safely freed without reading + * it. + * + * This is just an optimization targeted at large files. It may do + * nothing. It will return 0 unless things went badly. + */ +static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct inode *inode, u64 new_size) +{ + struct btrfs_key key; + int ret; + int nritems; + struct btrfs_key found_key; + struct btrfs_key other_key; + struct btrfs_leaf_ref *ref; + u64 leaf_gen; + u64 leaf_start; + + path->lowest_level = 1; + key.objectid = inode->i_ino; + key.type = BTRFS_CSUM_ITEM_KEY; + key.offset = new_size; +again: + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + + if (path->nodes[1] == NULL) { + ret = 0; + goto out; + } + ret = 0; + btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]); + nritems = btrfs_header_nritems(path->nodes[1]); + + if (!nritems) + goto out; + + if (path->slots[1] >= nritems) + goto next_node; + + /* did we find a key greater than anything we want to delete? */ + if (found_key.objectid > inode->i_ino || + (found_key.objectid == inode->i_ino && found_key.type > key.type)) + goto out; + + /* we check the next key in the node to make sure the leave contains + * only checksum items. This comparison doesn't work if our + * leaf is the last one in the node + */ + if (path->slots[1] + 1 >= nritems) { +next_node: + /* search forward from the last key in the node, this + * will bring us into the next node in the tree + */ + btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1); + + /* unlikely, but we inc below, so check to be safe */ + if (found_key.offset == (u64)-1) + goto out; + + /* search_forward needs a path with locks held, do the + * search again for the original key. It is possible + * this will race with a balance and return a path that + * we could modify, but this drop is just an optimization + * and is allowed to miss some leaves. + */ + btrfs_release_path(root, path); + found_key.offset++; + + /* setup a max key for search_forward */ + other_key.offset = (u64)-1; + other_key.type = key.type; + other_key.objectid = key.objectid; + + path->keep_locks = 1; + ret = btrfs_search_forward(root, &found_key, &other_key, + path, 0, 0); + path->keep_locks = 0; + if (ret || found_key.objectid != key.objectid || + found_key.type != key.type) { + ret = 0; + goto out; + } + + key.offset = found_key.offset; + btrfs_release_path(root, path); + cond_resched(); + goto again; + } + + /* we know there's one more slot after us in the tree, + * read that key so we can verify it is also a checksum item + */ + btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1); + + if (found_key.objectid < inode->i_ino) + goto next_key; + + if (found_key.type != key.type || found_key.offset < new_size) + goto next_key; + + /* + * if the key for the next leaf isn't a csum key from this objectid, + * we can't be sure there aren't good items inside this leaf. + * Bail out + */ + if (other_key.objectid != inode->i_ino || other_key.type != key.type) + goto out; + + leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]); + leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]); + /* + * it is safe to delete this leaf, it contains only + * csum items from this inode at an offset >= new_size + */ + ret = btrfs_del_leaf(trans, root, path, leaf_start); + BUG_ON(ret); + + if (root->ref_cows && leaf_gen < trans->transid) { + ref = btrfs_alloc_leaf_ref(root, 0); + if (ref) { + ref->root_gen = root->root_key.offset; + ref->bytenr = leaf_start; + ref->owner = 0; + ref->generation = leaf_gen; + ref->nritems = 0; + + ret = btrfs_add_leaf_ref(root, ref, 0); + WARN_ON(ret); + btrfs_free_leaf_ref(root, ref); + } else { + WARN_ON(1); + } + } +next_key: + btrfs_release_path(root, path); + + if (other_key.objectid == inode->i_ino && + other_key.type == key.type && other_key.offset > key.offset) { + key.offset = other_key.offset; + cond_resched(); + goto again; + } + ret = 0; +out: + /* fixup any changes we've made to the path */ + path->lowest_level = 0; + path->keep_locks = 0; + btrfs_release_path(root, path); + return ret; +} + +#endif + +/* + * this can truncate away extent items, csum items and directory items. + * It starts at a high offset and removes keys until it can't find + * any higher than new_size + * + * csum items that cross the new i_size are truncated to the new size + * as well. + * + * min_type is the minimum key type to truncate down to. If set to 0, this + * will kill all the items on this inode, including the INODE_ITEM_KEY. + */ +noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, + u64 new_size, u32 min_type) +{ + int ret; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + u32 found_type; + struct extent_buffer *leaf; + struct btrfs_file_extent_item *fi; + u64 extent_start = 0; + u64 extent_num_bytes = 0; + u64 item_end = 0; + u64 root_gen = 0; + u64 root_owner = 0; + int found_extent; + int del_item; + int pending_del_nr = 0; + int pending_del_slot = 0; + int extent_type = -1; + int encoding; + u64 mask = root->sectorsize - 1; + + if (root->ref_cows) + btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0); + path = btrfs_alloc_path(); + path->reada = -1; + BUG_ON(!path); + + /* FIXME, add redo link to tree so we don't leak on crash */ + key.objectid = inode->i_ino; + key.offset = (u64)-1; + key.type = (u8)-1; + + btrfs_init_path(path); + +search_again: + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto error; + + if (ret > 0) { + /* there are no items in the tree for us to truncate, we're + * done + */ + if (path->slots[0] == 0) { + ret = 0; + goto error; + } + path->slots[0]--; + } + + while (1) { + fi = NULL; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + found_type = btrfs_key_type(&found_key); + encoding = 0; + + if (found_key.objectid != inode->i_ino) + break; + + if (found_type < min_type) + break; + + item_end = found_key.offset; + if (found_type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + encoding = btrfs_file_extent_compression(leaf, fi); + encoding |= btrfs_file_extent_encryption(leaf, fi); + encoding |= btrfs_file_extent_other_encoding(leaf, fi); + + if (extent_type != BTRFS_FILE_EXTENT_INLINE) { + item_end += + btrfs_file_extent_num_bytes(leaf, fi); + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + item_end += btrfs_file_extent_inline_len(leaf, + fi); + } + item_end--; + } + if (item_end < new_size) { + if (found_type == BTRFS_DIR_ITEM_KEY) + found_type = BTRFS_INODE_ITEM_KEY; + else if (found_type == BTRFS_EXTENT_ITEM_KEY) + found_type = BTRFS_EXTENT_DATA_KEY; + else if (found_type == BTRFS_EXTENT_DATA_KEY) + found_type = BTRFS_XATTR_ITEM_KEY; + else if (found_type == BTRFS_XATTR_ITEM_KEY) + found_type = BTRFS_INODE_REF_KEY; + else if (found_type) + found_type--; + else + break; + btrfs_set_key_type(&key, found_type); + goto next; + } + if (found_key.offset >= new_size) + del_item = 1; + else + del_item = 0; + found_extent = 0; + + /* FIXME, shrink the extent if the ref count is only 1 */ + if (found_type != BTRFS_EXTENT_DATA_KEY) + goto delete; + + if (extent_type != BTRFS_FILE_EXTENT_INLINE) { + u64 num_dec; + extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); + if (!del_item && !encoding) { + u64 orig_num_bytes = + btrfs_file_extent_num_bytes(leaf, fi); + extent_num_bytes = new_size - + found_key.offset + root->sectorsize - 1; + extent_num_bytes = extent_num_bytes & + ~((u64)root->sectorsize - 1); + btrfs_set_file_extent_num_bytes(leaf, fi, + extent_num_bytes); + num_dec = (orig_num_bytes - + extent_num_bytes); + if (root->ref_cows && extent_start != 0) + inode_sub_bytes(inode, num_dec); + btrfs_mark_buffer_dirty(leaf); + } else { + extent_num_bytes = + btrfs_file_extent_disk_num_bytes(leaf, + fi); + /* FIXME blocksize != 4096 */ + num_dec = btrfs_file_extent_num_bytes(leaf, fi); + if (extent_start != 0) { + found_extent = 1; + if (root->ref_cows) + inode_sub_bytes(inode, num_dec); + } + root_gen = btrfs_header_generation(leaf); + root_owner = btrfs_header_owner(leaf); + } + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + /* + * we can't truncate inline items that have had + * special encodings + */ + if (!del_item && + btrfs_file_extent_compression(leaf, fi) == 0 && + btrfs_file_extent_encryption(leaf, fi) == 0 && + btrfs_file_extent_other_encoding(leaf, fi) == 0) { + u32 size = new_size - found_key.offset; + + if (root->ref_cows) { + inode_sub_bytes(inode, item_end + 1 - + new_size); + } + size = + btrfs_file_extent_calc_inline_size(size); + ret = btrfs_truncate_item(trans, root, path, + size, 1); + BUG_ON(ret); + } else if (root->ref_cows) { + inode_sub_bytes(inode, item_end + 1 - + found_key.offset); + } + } +delete: + if (del_item) { + if (!pending_del_nr) { + /* no pending yet, add ourselves */ + pending_del_slot = path->slots[0]; + pending_del_nr = 1; + } else if (pending_del_nr && + path->slots[0] + 1 == pending_del_slot) { + /* hop on the pending chunk */ + pending_del_nr++; + pending_del_slot = path->slots[0]; + } else { + BUG(); + } + } else { + break; + } + if (found_extent) { + ret = btrfs_free_extent(trans, root, extent_start, + extent_num_bytes, + leaf->start, root_owner, + root_gen, inode->i_ino, 0); + BUG_ON(ret); + } +next: + if (path->slots[0] == 0) { + if (pending_del_nr) + goto del_pending; + btrfs_release_path(root, path); + goto search_again; + } + + path->slots[0]--; + if (pending_del_nr && + path->slots[0] + 1 != pending_del_slot) { + struct btrfs_key debug; +del_pending: + btrfs_item_key_to_cpu(path->nodes[0], &debug, + pending_del_slot); + ret = btrfs_del_items(trans, root, path, + pending_del_slot, + pending_del_nr); + BUG_ON(ret); + pending_del_nr = 0; + btrfs_release_path(root, path); + goto search_again; + } + } + ret = 0; +error: + if (pending_del_nr) { + ret = btrfs_del_items(trans, root, path, pending_del_slot, + pending_del_nr); + } + btrfs_free_path(path); + inode->i_sb->s_dirt = 1; + return ret; +} + +/* + * taken from block_truncate_page, but does cow as it zeros out + * any bytes left in the last page in the file. + */ +static int btrfs_truncate_page(struct address_space *mapping, loff_t from) +{ + struct inode *inode = mapping->host; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + char *kaddr; + u32 blocksize = root->sectorsize; + pgoff_t index = from >> PAGE_CACHE_SHIFT; + unsigned offset = from & (PAGE_CACHE_SIZE-1); + struct page *page; + int ret = 0; + u64 page_start; + u64 page_end; + + if ((offset & (blocksize - 1)) == 0) + goto out; + + ret = -ENOMEM; +again: + page = grab_cache_page(mapping, index); + if (!page) + goto out; + + page_start = page_offset(page); + page_end = page_start + PAGE_CACHE_SIZE - 1; + + if (!PageUptodate(page)) { + ret = btrfs_readpage(NULL, page); + lock_page(page); + if (page->mapping != mapping) { + unlock_page(page); + page_cache_release(page); + goto again; + } + if (!PageUptodate(page)) { + ret = -EIO; + goto out_unlock; + } + } + wait_on_page_writeback(page); + + lock_extent(io_tree, page_start, page_end, GFP_NOFS); + set_page_extent_mapped(page); + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + btrfs_set_extent_delalloc(inode, page_start, page_end); + ret = 0; + if (offset != PAGE_CACHE_SIZE) { + kaddr = kmap(page); + memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); + flush_dcache_page(page); + kunmap(page); + } + ClearPageChecked(page); + set_page_dirty(page); + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + +out_unlock: + unlock_page(page); + page_cache_release(page); +out: + return ret; +} + +int btrfs_cont_expand(struct inode *inode, loff_t size) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map *em; + u64 mask = root->sectorsize - 1; + u64 hole_start = (inode->i_size + mask) & ~mask; + u64 block_end = (size + mask) & ~mask; + u64 last_byte; + u64 cur_offset; + u64 hole_size; + int err; + + if (size <= hole_start) + return 0; + + err = btrfs_check_free_space(root, 1, 0); + if (err) + return err; + + btrfs_truncate_page(inode->i_mapping, inode->i_size); + + while (1) { + struct btrfs_ordered_extent *ordered; + btrfs_wait_ordered_range(inode, hole_start, + block_end - hole_start); + lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS); + ordered = btrfs_lookup_ordered_extent(inode, hole_start); + if (!ordered) + break; + unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS); + btrfs_put_ordered_extent(ordered); + } + + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, inode); + + cur_offset = hole_start; + while (1) { + em = btrfs_get_extent(inode, NULL, 0, cur_offset, + block_end - cur_offset, 0); + BUG_ON(IS_ERR(em) || !em); + last_byte = min(extent_map_end(em), block_end); + last_byte = (last_byte + mask) & ~mask; + if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) { + u64 hint_byte = 0; + hole_size = last_byte - cur_offset; + err = btrfs_drop_extents(trans, root, inode, + cur_offset, + cur_offset + hole_size, + cur_offset, &hint_byte); + if (err) + break; + err = btrfs_insert_file_extent(trans, root, + inode->i_ino, cur_offset, 0, + 0, hole_size, 0, hole_size, + 0, 0, 0); + btrfs_drop_extent_cache(inode, hole_start, + last_byte - 1, 0); + } + free_extent_map(em); + cur_offset = last_byte; + if (err || cur_offset >= block_end) + break; + } + + btrfs_end_transaction(trans, root); + unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS); + return err; +} + +static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = dentry->d_inode; + int err; + + err = inode_change_ok(inode, attr); + if (err) + return err; + + if (S_ISREG(inode->i_mode) && + attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) { + err = btrfs_cont_expand(inode, attr->ia_size); + if (err) + return err; + } + + err = inode_setattr(inode, attr); + + if (!err && ((attr->ia_valid & ATTR_MODE))) + err = btrfs_acl_chmod(inode); + return err; +} + +void btrfs_delete_inode(struct inode *inode) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(inode)->root; + unsigned long nr; + int ret; + + truncate_inode_pages(&inode->i_data, 0); + if (is_bad_inode(inode)) { + btrfs_orphan_del(NULL, inode); + goto no_delete; + } + btrfs_wait_ordered_range(inode, 0, (u64)-1); + + btrfs_i_size_write(inode, 0); + trans = btrfs_join_transaction(root, 1); + + btrfs_set_trans_block_group(trans, inode); + ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0); + if (ret) { + btrfs_orphan_del(NULL, inode); + goto no_delete_lock; + } + + btrfs_orphan_del(trans, inode); + + nr = trans->blocks_used; + clear_inode(inode); + + btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root, nr); + return; + +no_delete_lock: + nr = trans->blocks_used; + btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root, nr); +no_delete: + clear_inode(inode); +} + +/* + * this returns the key found in the dir entry in the location pointer. + * If no dir entries were found, location->objectid is 0. + */ +static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, + struct btrfs_key *location) +{ + 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_I(dir)->root; + int ret = 0; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name, + namelen, 0); + if (IS_ERR(di)) + ret = PTR_ERR(di); + + if (!di || IS_ERR(di)) + goto out_err; + + btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); +out: + btrfs_free_path(path); + return ret; +out_err: + location->objectid = 0; + goto out; +} + +/* + * when we hit a tree root in a directory, the btrfs part of the inode + * needs to be changed to reflect the root directory of the tree root. This + * is kind of like crossing a mount point. + */ +static int fixup_tree_root_location(struct btrfs_root *root, + struct btrfs_key *location, + struct btrfs_root **sub_root, + struct dentry *dentry) +{ + struct btrfs_root_item *ri; + + if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY) + return 0; + if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) + return 0; + + *sub_root = btrfs_read_fs_root(root->fs_info, location, + dentry->d_name.name, + dentry->d_name.len); + if (IS_ERR(*sub_root)) + return PTR_ERR(*sub_root); + + ri = &(*sub_root)->root_item; + location->objectid = btrfs_root_dirid(ri); + btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); + location->offset = 0; + + return 0; +} + +static noinline void init_btrfs_i(struct inode *inode) +{ + struct btrfs_inode *bi = BTRFS_I(inode); + + bi->i_acl = NULL; + bi->i_default_acl = NULL; + + bi->generation = 0; + bi->sequence = 0; + bi->last_trans = 0; + bi->logged_trans = 0; + bi->delalloc_bytes = 0; + bi->disk_i_size = 0; + bi->flags = 0; + bi->index_cnt = (u64)-1; + bi->log_dirty_trans = 0; + extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS); + extent_io_tree_init(&BTRFS_I(inode)->io_tree, + inode->i_mapping, GFP_NOFS); + extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree, + inode->i_mapping, GFP_NOFS); + INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes); + btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree); + mutex_init(&BTRFS_I(inode)->extent_mutex); + mutex_init(&BTRFS_I(inode)->log_mutex); +} + +static int btrfs_init_locked_inode(struct inode *inode, void *p) +{ + struct btrfs_iget_args *args = p; + inode->i_ino = args->ino; + init_btrfs_i(inode); + BTRFS_I(inode)->root = args->root; + return 0; +} + +static int btrfs_find_actor(struct inode *inode, void *opaque) +{ + struct btrfs_iget_args *args = opaque; + return args->ino == inode->i_ino && + args->root == BTRFS_I(inode)->root; +} + +struct inode *btrfs_ilookup(struct super_block *s, u64 objectid, + struct btrfs_root *root, int wait) +{ + struct inode *inode; + struct btrfs_iget_args args; + args.ino = objectid; + args.root = root; + + if (wait) { + inode = ilookup5(s, objectid, btrfs_find_actor, + (void *)&args); + } else { + inode = ilookup5_nowait(s, objectid, btrfs_find_actor, + (void *)&args); + } + return inode; +} + +struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid, + struct btrfs_root *root) +{ + struct inode *inode; + struct btrfs_iget_args args; + args.ino = objectid; + args.root = root; + + inode = iget5_locked(s, objectid, btrfs_find_actor, + btrfs_init_locked_inode, + (void *)&args); + return inode; +} + +/* Get an inode object given its location and corresponding root. + * Returns in *is_new if the inode was read from disk + */ +struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, + struct btrfs_root *root, int *is_new) +{ + struct inode *inode; + + inode = btrfs_iget_locked(s, location->objectid, root); + if (!inode) + return ERR_PTR(-EACCES); + + if (inode->i_state & I_NEW) { + BTRFS_I(inode)->root = root; + memcpy(&BTRFS_I(inode)->location, location, sizeof(*location)); + btrfs_read_locked_inode(inode); + unlock_new_inode(inode); + if (is_new) + *is_new = 1; + } else { + if (is_new) + *is_new = 0; + } + + return inode; +} + +struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode; + struct btrfs_inode *bi = BTRFS_I(dir); + struct btrfs_root *root = bi->root; + struct btrfs_root *sub_root = root; + struct btrfs_key location; + int ret, new; + + if (dentry->d_name.len > BTRFS_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + ret = btrfs_inode_by_name(dir, dentry, &location); + + if (ret < 0) + return ERR_PTR(ret); + + inode = NULL; + if (location.objectid) { + ret = fixup_tree_root_location(root, &location, &sub_root, + dentry); + if (ret < 0) + return ERR_PTR(ret); + if (ret > 0) + return ERR_PTR(-ENOENT); + inode = btrfs_iget(dir->i_sb, &location, sub_root, &new); + if (IS_ERR(inode)) + return ERR_CAST(inode); + } + return inode; +} + +static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + struct inode *inode; + + if (dentry->d_name.len > BTRFS_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + inode = btrfs_lookup_dentry(dir, dentry); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + return d_splice_alias(inode, dentry); +} + +static unsigned char btrfs_filetype_table[] = { + DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK +}; + +static int btrfs_real_readdir(struct file *filp, void *dirent, + filldir_t filldir) +{ + struct inode *inode = filp->f_dentry->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_item *item; + struct btrfs_dir_item *di; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + int ret; + u32 nritems; + struct extent_buffer *leaf; + int slot; + int advance; + unsigned char d_type; + int over = 0; + u32 di_cur; + u32 di_total; + u32 di_len; + int key_type = BTRFS_DIR_INDEX_KEY; + char tmp_name[32]; + char *name_ptr; + int name_len; + + /* FIXME, use a real flag for deciding about the key type */ + if (root->fs_info->tree_root == root) + key_type = BTRFS_DIR_ITEM_KEY; + + /* special case for "." */ + if (filp->f_pos == 0) { + over = filldir(dirent, ".", 1, + 1, inode->i_ino, + DT_DIR); + if (over) + return 0; + filp->f_pos = 1; + } + /* special case for .., just use the back ref */ + if (filp->f_pos == 1) { + u64 pino = parent_ino(filp->f_path.dentry); + over = filldir(dirent, "..", 2, + 2, pino, DT_DIR); + if (over) + return 0; + filp->f_pos = 2; + } + path = btrfs_alloc_path(); + path->reada = 2; + + btrfs_set_key_type(&key, key_type); + key.offset = filp->f_pos; + key.objectid = inode->i_ino; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + advance = 0; + + while (1) { + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + slot = path->slots[0]; + if (advance || slot >= nritems) { + if (slot >= nritems - 1) { + ret = btrfs_next_leaf(root, path); + if (ret) + break; + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + slot = path->slots[0]; + } else { + slot++; + path->slots[0]++; + } + } + + advance = 1; + item = btrfs_item_nr(leaf, slot); + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid != key.objectid) + break; + if (btrfs_key_type(&found_key) != key_type) + break; + if (found_key.offset < filp->f_pos) + continue; + + filp->f_pos = found_key.offset; + + di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); + di_cur = 0; + di_total = btrfs_item_size(leaf, item); + + while (di_cur < di_total) { + struct btrfs_key location; + + name_len = btrfs_dir_name_len(leaf, di); + if (name_len <= sizeof(tmp_name)) { + name_ptr = tmp_name; + } else { + name_ptr = kmalloc(name_len, GFP_NOFS); + if (!name_ptr) { + ret = -ENOMEM; + goto err; + } + } + read_extent_buffer(leaf, name_ptr, + (unsigned long)(di + 1), name_len); + + d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; + btrfs_dir_item_key_to_cpu(leaf, di, &location); + + /* is this a reference to our own snapshot? If so + * skip it + */ + if (location.type == BTRFS_ROOT_ITEM_KEY && + location.objectid == root->root_key.objectid) { + over = 0; + goto skip; + } + over = filldir(dirent, name_ptr, name_len, + found_key.offset, location.objectid, + d_type); + +skip: + if (name_ptr != tmp_name) + kfree(name_ptr); + + if (over) + goto nopos; + di_len = btrfs_dir_name_len(leaf, di) + + btrfs_dir_data_len(leaf, di) + sizeof(*di); + di_cur += di_len; + di = (struct btrfs_dir_item *)((char *)di + di_len); + } + } + + /* Reached end of directory/root. Bump pos past the last item. */ + if (key_type == BTRFS_DIR_INDEX_KEY) + filp->f_pos = INT_LIMIT(typeof(filp->f_pos)); + else + filp->f_pos++; +nopos: + ret = 0; +err: + btrfs_free_path(path); + return ret; +} + +int btrfs_write_inode(struct inode *inode, int wait) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + int ret = 0; + + if (root->fs_info->btree_inode == inode) + return 0; + + if (wait) { + trans = btrfs_join_transaction(root, 1); + btrfs_set_trans_block_group(trans, inode); + ret = btrfs_commit_transaction(trans, root); + } + return ret; +} + +/* + * This is somewhat expensive, updating the tree every time the + * inode changes. But, it is most likely to find the inode in cache. + * FIXME, needs more benchmarking...there are no reasons other than performance + * to keep or drop this code. + */ +void btrfs_dirty_inode(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + + trans = btrfs_join_transaction(root, 1); + btrfs_set_trans_block_group(trans, inode); + btrfs_update_inode(trans, root, inode); + btrfs_end_transaction(trans, root); +} + +/* + * find the highest existing sequence number in a directory + * and then set the in-memory index_cnt variable to reflect + * free sequence numbers + */ +static int btrfs_set_inode_index_count(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key key, found_key; + struct btrfs_path *path; + struct extent_buffer *leaf; + int ret; + + key.objectid = inode->i_ino; + btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); + key.offset = (u64)-1; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + /* FIXME: we should be able to handle this */ + if (ret == 0) + goto out; + ret = 0; + + /* + * MAGIC NUMBER EXPLANATION: + * since we search a directory based on f_pos we have to start at 2 + * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody + * else has to start at 2 + */ + if (path->slots[0] == 0) { + BTRFS_I(inode)->index_cnt = 2; + goto out; + } + + path->slots[0]--; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid != inode->i_ino || + btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) { + BTRFS_I(inode)->index_cnt = 2; + goto out; + } + + BTRFS_I(inode)->index_cnt = found_key.offset + 1; +out: + btrfs_free_path(path); + return ret; +} + +/* + * helper to find a free sequence number in a given directory. This current + * code is very simple, later versions will do smarter things in the btree + */ +int btrfs_set_inode_index(struct inode *dir, u64 *index) +{ + int ret = 0; + + if (BTRFS_I(dir)->index_cnt == (u64)-1) { + ret = btrfs_set_inode_index_count(dir); + if (ret) + return ret; + } + + *index = BTRFS_I(dir)->index_cnt; + BTRFS_I(dir)->index_cnt++; + + return ret; +} + +static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, + const char *name, int name_len, + u64 ref_objectid, u64 objectid, + u64 alloc_hint, int mode, u64 *index) +{ + struct inode *inode; + struct btrfs_inode_item *inode_item; + struct btrfs_key *location; + struct btrfs_path *path; + struct btrfs_inode_ref *ref; + struct btrfs_key key[2]; + u32 sizes[2]; + unsigned long ptr; + int ret; + int owner; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + inode = new_inode(root->fs_info->sb); + if (!inode) + return ERR_PTR(-ENOMEM); + + if (dir) { + ret = btrfs_set_inode_index(dir, index); + if (ret) + return ERR_PTR(ret); + } + /* + * index_cnt is ignored for everything but a dir, + * btrfs_get_inode_index_count has an explanation for the magic + * number + */ + init_btrfs_i(inode); + BTRFS_I(inode)->index_cnt = 2; + BTRFS_I(inode)->root = root; + BTRFS_I(inode)->generation = trans->transid; + + if (mode & S_IFDIR) + owner = 0; + else + owner = 1; + BTRFS_I(inode)->block_group = + btrfs_find_block_group(root, 0, alloc_hint, owner); + if ((mode & S_IFREG)) { + if (btrfs_test_opt(root, NODATASUM)) + btrfs_set_flag(inode, NODATASUM); + if (btrfs_test_opt(root, NODATACOW)) + btrfs_set_flag(inode, NODATACOW); + } + + key[0].objectid = objectid; + btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY); + key[0].offset = 0; + + key[1].objectid = objectid; + btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); + key[1].offset = ref_objectid; + + sizes[0] = sizeof(struct btrfs_inode_item); + sizes[1] = name_len + sizeof(*ref); + + ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2); + if (ret != 0) + goto fail; + + if (objectid > root->highest_inode) + root->highest_inode = objectid; + + inode->i_uid = current_fsuid(); + inode->i_gid = current_fsgid(); + inode->i_mode = mode; + inode->i_ino = objectid; + inode_set_bytes(inode, 0); + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; + inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + fill_inode_item(trans, path->nodes[0], inode_item, inode); + + ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, + struct btrfs_inode_ref); + btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); + btrfs_set_inode_ref_index(path->nodes[0], ref, *index); + ptr = (unsigned long)(ref + 1); + write_extent_buffer(path->nodes[0], name, ptr, name_len); + + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_free_path(path); + + location = &BTRFS_I(inode)->location; + location->objectid = objectid; + location->offset = 0; + btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); + + insert_inode_hash(inode); + return inode; +fail: + if (dir) + BTRFS_I(dir)->index_cnt--; + btrfs_free_path(path); + return ERR_PTR(ret); +} + +static inline u8 btrfs_inode_type(struct inode *inode) +{ + return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; +} + +/* + * utility function to add 'inode' into 'parent_inode' with + * a give name and a given sequence number. + * if 'add_backref' is true, also insert a backref from the + * inode to the parent directory. + */ +int btrfs_add_link(struct btrfs_trans_handle *trans, + struct inode *parent_inode, struct inode *inode, + const char *name, int name_len, int add_backref, u64 index) +{ + int ret; + struct btrfs_key key; + struct btrfs_root *root = BTRFS_I(parent_inode)->root; + + key.objectid = inode->i_ino; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + key.offset = 0; + + ret = btrfs_insert_dir_item(trans, root, name, name_len, + parent_inode->i_ino, + &key, btrfs_inode_type(inode), + index); + if (ret == 0) { + if (add_backref) { + ret = btrfs_insert_inode_ref(trans, root, + name, name_len, + inode->i_ino, + parent_inode->i_ino, + index); + } + btrfs_i_size_write(parent_inode, parent_inode->i_size + + name_len * 2); + parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; + ret = btrfs_update_inode(trans, root, parent_inode); + } + return ret; +} + +static int btrfs_add_nondir(struct btrfs_trans_handle *trans, + struct dentry *dentry, struct inode *inode, + int backref, u64 index) +{ + int err = btrfs_add_link(trans, dentry->d_parent->d_inode, + inode, dentry->d_name.name, + dentry->d_name.len, backref, index); + if (!err) { + d_instantiate(dentry, inode); + return 0; + } + if (err > 0) + err = -EEXIST; + return err; +} + +static int btrfs_mknod(struct inode *dir, struct dentry *dentry, + int mode, dev_t rdev) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + int err; + int drop_inode = 0; + u64 objectid; + unsigned long nr = 0; + u64 index = 0; + + if (!new_valid_dev(rdev)) + return -EINVAL; + + err = btrfs_check_free_space(root, 1, 0); + if (err) + goto fail; + + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, dir); + + err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); + if (err) { + err = -ENOSPC; + goto out_unlock; + } + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, + dentry->d_parent->d_inode->i_ino, objectid, + BTRFS_I(dir)->block_group, mode, &index); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_unlock; + + err = btrfs_init_acl(inode, dir); + if (err) { + drop_inode = 1; + goto out_unlock; + } + + btrfs_set_trans_block_group(trans, inode); + err = btrfs_add_nondir(trans, dentry, inode, 0, index); + if (err) + drop_inode = 1; + else { + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, rdev); + btrfs_update_inode(trans, root, inode); + } + dir->i_sb->s_dirt = 1; + btrfs_update_inode_block_group(trans, inode); + btrfs_update_inode_block_group(trans, dir); +out_unlock: + nr = trans->blocks_used; + btrfs_end_transaction_throttle(trans, root); +fail: + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(root, nr); + 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_I(dir)->root; + struct inode *inode = NULL; + int err; + int drop_inode = 0; + unsigned long nr = 0; + u64 objectid; + u64 index = 0; + + err = btrfs_check_free_space(root, 1, 0); + if (err) + goto fail; + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, dir); + + err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); + if (err) { + err = -ENOSPC; + goto out_unlock; + } + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, + dentry->d_parent->d_inode->i_ino, + objectid, BTRFS_I(dir)->block_group, mode, + &index); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_unlock; + + err = btrfs_init_acl(inode, dir); + if (err) { + drop_inode = 1; + goto out_unlock; + } + + btrfs_set_trans_block_group(trans, inode); + err = btrfs_add_nondir(trans, dentry, inode, 0, index); + if (err) + drop_inode = 1; + else { + inode->i_mapping->a_ops = &btrfs_aops; + inode->i_mapping->backing_dev_info = &root->fs_info->bdi; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + } + dir->i_sb->s_dirt = 1; + btrfs_update_inode_block_group(trans, inode); + btrfs_update_inode_block_group(trans, dir); +out_unlock: + nr = trans->blocks_used; + btrfs_end_transaction_throttle(trans, root); +fail: + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(root, nr); + return err; +} + +static int btrfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = old_dentry->d_inode; + u64 index; + unsigned long nr = 0; + int err; + int drop_inode = 0; + + if (inode->i_nlink == 0) + return -ENOENT; + + btrfs_inc_nlink(inode); + err = btrfs_check_free_space(root, 1, 0); + if (err) + goto fail; + err = btrfs_set_inode_index(dir, &index); + if (err) + goto fail; + + trans = btrfs_start_transaction(root, 1); + + btrfs_set_trans_block_group(trans, dir); + atomic_inc(&inode->i_count); + + err = btrfs_add_nondir(trans, dentry, inode, 1, index); + + if (err) + drop_inode = 1; + + dir->i_sb->s_dirt = 1; + btrfs_update_inode_block_group(trans, dir); + err = btrfs_update_inode(trans, root, inode); + + if (err) + drop_inode = 1; + + nr = trans->blocks_used; + btrfs_end_transaction_throttle(trans, root); +fail: + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(root, nr); + return err; +} + +static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ + struct inode *inode = NULL; + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + int err = 0; + int drop_on_err = 0; + u64 objectid = 0; + u64 index = 0; + unsigned long nr = 1; + + err = btrfs_check_free_space(root, 1, 0); + if (err) + goto out_unlock; + + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, dir); + + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto out_unlock; + } + + err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); + if (err) { + err = -ENOSPC; + goto out_unlock; + } + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, + dentry->d_parent->d_inode->i_ino, objectid, + BTRFS_I(dir)->block_group, S_IFDIR | mode, + &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_fail; + } + + drop_on_err = 1; + + err = btrfs_init_acl(inode, dir); + if (err) + goto out_fail; + + inode->i_op = &btrfs_dir_inode_operations; + inode->i_fop = &btrfs_dir_file_operations; + btrfs_set_trans_block_group(trans, inode); + + btrfs_i_size_write(inode, 0); + err = btrfs_update_inode(trans, root, inode); + if (err) + goto out_fail; + + err = btrfs_add_link(trans, dentry->d_parent->d_inode, + inode, dentry->d_name.name, + dentry->d_name.len, 0, index); + if (err) + goto out_fail; + + d_instantiate(dentry, inode); + drop_on_err = 0; + dir->i_sb->s_dirt = 1; + btrfs_update_inode_block_group(trans, inode); + btrfs_update_inode_block_group(trans, dir); + +out_fail: + nr = trans->blocks_used; + btrfs_end_transaction_throttle(trans, root); + +out_unlock: + if (drop_on_err) + iput(inode); + btrfs_btree_balance_dirty(root, nr); + return err; +} + +/* helper for btfs_get_extent. Given an existing extent in the tree, + * and an extent that you want to insert, deal with overlap and insert + * the new extent into the tree. + */ +static int merge_extent_mapping(struct extent_map_tree *em_tree, + struct extent_map *existing, + struct extent_map *em, + u64 map_start, u64 map_len) +{ + u64 start_diff; + + BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); + start_diff = map_start - em->start; + em->start = map_start; + em->len = map_len; + if (em->block_start < EXTENT_MAP_LAST_BYTE && + !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { + em->block_start += start_diff; + em->block_len -= start_diff; + } + return add_extent_mapping(em_tree, em); +} + +static noinline int uncompress_inline(struct btrfs_path *path, + struct inode *inode, struct page *page, + size_t pg_offset, u64 extent_offset, + struct btrfs_file_extent_item *item) +{ + int ret; + struct extent_buffer *leaf = path->nodes[0]; + char *tmp; + size_t max_size; + unsigned long inline_size; + unsigned long ptr; + + WARN_ON(pg_offset != 0); + max_size = btrfs_file_extent_ram_bytes(leaf, item); + inline_size = btrfs_file_extent_inline_item_len(leaf, + btrfs_item_nr(leaf, path->slots[0])); + tmp = kmalloc(inline_size, GFP_NOFS); + ptr = btrfs_file_extent_inline_start(item); + + read_extent_buffer(leaf, tmp, ptr, inline_size); + + max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); + ret = btrfs_zlib_decompress(tmp, page, extent_offset, + inline_size, max_size); + if (ret) { + char *kaddr = kmap_atomic(page, KM_USER0); + unsigned long copy_size = min_t(u64, + PAGE_CACHE_SIZE - pg_offset, + max_size - extent_offset); + memset(kaddr + pg_offset, 0, copy_size); + kunmap_atomic(kaddr, KM_USER0); + } + kfree(tmp); + return 0; +} + +/* + * a bit scary, this does extent mapping from logical file offset to the disk. + * the ugly parts come from merging extents from the disk with the in-ram + * representation. This gets more complex because of the data=ordered code, + * where the in-ram extents might be locked pending data=ordered completion. + * + * This also copies inline extents directly into the page. + */ + +struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, + size_t pg_offset, u64 start, u64 len, + int create) +{ + int ret; + int err = 0; + u64 bytenr; + u64 extent_start = 0; + u64 extent_end = 0; + u64 objectid = inode->i_ino; + u32 found_type; + struct btrfs_path *path = NULL; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_file_extent_item *item; + struct extent_buffer *leaf; + struct btrfs_key found_key; + struct extent_map *em = NULL; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_trans_handle *trans = NULL; + int compressed; + +again: + spin_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, start, len); + if (em) + em->bdev = root->fs_info->fs_devices->latest_bdev; + spin_unlock(&em_tree->lock); + + if (em) { + if (em->start > start || em->start + em->len <= start) + free_extent_map(em); + else if (em->block_start == EXTENT_MAP_INLINE && page) + free_extent_map(em); + else + goto out; + } + em = alloc_extent_map(GFP_NOFS); + if (!em) { + err = -ENOMEM; + goto out; + } + em->bdev = root->fs_info->fs_devices->latest_bdev; + em->start = EXTENT_MAP_HOLE; + em->orig_start = EXTENT_MAP_HOLE; + em->len = (u64)-1; + em->block_len = (u64)-1; + + if (!path) { + path = btrfs_alloc_path(); + BUG_ON(!path); + } + + ret = btrfs_lookup_file_extent(trans, root, path, + objectid, start, trans != NULL); + if (ret < 0) { + err = ret; + goto out; + } + + if (ret != 0) { + if (path->slots[0] == 0) + goto not_found; + path->slots[0]--; + } + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + /* are we inside the extent that was found? */ + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + found_type = btrfs_key_type(&found_key); + if (found_key.objectid != objectid || + found_type != BTRFS_EXTENT_DATA_KEY) { + goto not_found; + } + + found_type = btrfs_file_extent_type(leaf, item); + extent_start = found_key.offset; + compressed = btrfs_file_extent_compression(leaf, item); + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + extent_end = extent_start + + btrfs_file_extent_num_bytes(leaf, item); + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + size_t size; + size = btrfs_file_extent_inline_len(leaf, item); + extent_end = (extent_start + size + root->sectorsize - 1) & + ~((u64)root->sectorsize - 1); + } + + if (start >= extent_end) { + path->slots[0]++; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) { + err = ret; + goto out; + } + if (ret > 0) + goto not_found; + leaf = path->nodes[0]; + } + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != objectid || + found_key.type != BTRFS_EXTENT_DATA_KEY) + goto not_found; + if (start + len <= found_key.offset) + goto not_found; + em->start = start; + em->len = found_key.offset - start; + goto not_found_em; + } + + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + em->start = extent_start; + em->len = extent_end - extent_start; + em->orig_start = extent_start - + btrfs_file_extent_offset(leaf, item); + bytenr = btrfs_file_extent_disk_bytenr(leaf, item); + if (bytenr == 0) { + em->block_start = EXTENT_MAP_HOLE; + goto insert; + } + if (compressed) { + set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + em->block_start = bytenr; + em->block_len = btrfs_file_extent_disk_num_bytes(leaf, + item); + } else { + bytenr += btrfs_file_extent_offset(leaf, item); + em->block_start = bytenr; + em->block_len = em->len; + if (found_type == BTRFS_FILE_EXTENT_PREALLOC) + set_bit(EXTENT_FLAG_PREALLOC, &em->flags); + } + goto insert; + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + unsigned long ptr; + char *map; + size_t size; + size_t extent_offset; + size_t copy_size; + + em->block_start = EXTENT_MAP_INLINE; + if (!page || create) { + em->start = extent_start; + em->len = extent_end - extent_start; + goto out; + } + + size = btrfs_file_extent_inline_len(leaf, item); + extent_offset = page_offset(page) + pg_offset - extent_start; + copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, + size - extent_offset); + em->start = extent_start + extent_offset; + em->len = (copy_size + root->sectorsize - 1) & + ~((u64)root->sectorsize - 1); + em->orig_start = EXTENT_MAP_INLINE; + if (compressed) + set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + ptr = btrfs_file_extent_inline_start(item) + extent_offset; + if (create == 0 && !PageUptodate(page)) { + if (btrfs_file_extent_compression(leaf, item) == + BTRFS_COMPRESS_ZLIB) { + ret = uncompress_inline(path, inode, page, + pg_offset, + extent_offset, item); + BUG_ON(ret); + } else { + map = kmap(page); + read_extent_buffer(leaf, map + pg_offset, ptr, + copy_size); + kunmap(page); + } + flush_dcache_page(page); + } else if (create && PageUptodate(page)) { + if (!trans) { + kunmap(page); + free_extent_map(em); + em = NULL; + btrfs_release_path(root, path); + trans = btrfs_join_transaction(root, 1); + goto again; + } + map = kmap(page); + write_extent_buffer(leaf, map + pg_offset, ptr, + copy_size); + kunmap(page); + btrfs_mark_buffer_dirty(leaf); + } + set_extent_uptodate(io_tree, em->start, + extent_map_end(em) - 1, GFP_NOFS); + goto insert; + } else { + printk(KERN_ERR "btrfs unknown found_type %d\n", found_type); + WARN_ON(1); + } +not_found: + em->start = start; + em->len = len; +not_found_em: + em->block_start = EXTENT_MAP_HOLE; + set_bit(EXTENT_FLAG_VACANCY, &em->flags); +insert: + btrfs_release_path(root, path); + if (em->start > start || extent_map_end(em) <= start) { + printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed " + "[%llu %llu]\n", (unsigned long long)em->start, + (unsigned long long)em->len, + (unsigned long long)start, + (unsigned long long)len); + err = -EIO; + goto out; + } + + err = 0; + spin_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + /* it is possible that someone inserted the extent into the tree + * while we had the lock dropped. It is also possible that + * an overlapping map exists in the tree + */ + if (ret == -EEXIST) { + struct extent_map *existing; + + ret = 0; + + existing = lookup_extent_mapping(em_tree, start, len); + if (existing && (existing->start > start || + existing->start + existing->len <= start)) { + free_extent_map(existing); + existing = NULL; + } + if (!existing) { + existing = lookup_extent_mapping(em_tree, em->start, + em->len); + if (existing) { + err = merge_extent_mapping(em_tree, existing, + em, start, + root->sectorsize); + free_extent_map(existing); + if (err) { + free_extent_map(em); + em = NULL; + } + } else { + err = -EIO; + free_extent_map(em); + em = NULL; + } + } else { + free_extent_map(em); + em = existing; + err = 0; + } + } + spin_unlock(&em_tree->lock); +out: + if (path) + btrfs_free_path(path); + if (trans) { + ret = btrfs_end_transaction(trans, root); + if (!err) + err = ret; + } + if (err) { + free_extent_map(em); + WARN_ON(1); + return ERR_PTR(err); + } + return em; +} + +static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, + const struct iovec *iov, loff_t offset, + unsigned long nr_segs) +{ + return -EINVAL; +} + +static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock) +{ + return extent_bmap(mapping, iblock, btrfs_get_extent); +} + +int btrfs_readpage(struct file *file, struct page *page) +{ + struct extent_io_tree *tree; + tree = &BTRFS_I(page->mapping->host)->io_tree; + return extent_read_full_page(tree, page, btrfs_get_extent); +} + +static int btrfs_writepage(struct page *page, struct writeback_control *wbc) +{ + struct extent_io_tree *tree; + + + if (current->flags & PF_MEMALLOC) { + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return 0; + } + tree = &BTRFS_I(page->mapping->host)->io_tree; + return extent_write_full_page(tree, page, btrfs_get_extent, wbc); +} + +int btrfs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct extent_io_tree *tree; + + tree = &BTRFS_I(mapping->host)->io_tree; + return extent_writepages(tree, mapping, btrfs_get_extent, wbc); +} + +static int +btrfs_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + struct extent_io_tree *tree; + tree = &BTRFS_I(mapping->host)->io_tree; + return extent_readpages(tree, mapping, pages, nr_pages, + btrfs_get_extent); +} +static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) +{ + struct extent_io_tree *tree; + struct extent_map_tree *map; + int ret; + + tree = &BTRFS_I(page->mapping->host)->io_tree; + map = &BTRFS_I(page->mapping->host)->extent_tree; + ret = try_release_extent_mapping(map, tree, page, gfp_flags); + if (ret == 1) { + ClearPagePrivate(page); + set_page_private(page, 0); + page_cache_release(page); + } + return ret; +} + +static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) +{ + if (PageWriteback(page) || PageDirty(page)) + return 0; + return __btrfs_releasepage(page, gfp_flags); +} + +static void btrfs_invalidatepage(struct page *page, unsigned long offset) +{ + struct extent_io_tree *tree; + struct btrfs_ordered_extent *ordered; + u64 page_start = page_offset(page); + u64 page_end = page_start + PAGE_CACHE_SIZE - 1; + + wait_on_page_writeback(page); + tree = &BTRFS_I(page->mapping->host)->io_tree; + if (offset) { + btrfs_releasepage(page, GFP_NOFS); + return; + } + + lock_extent(tree, page_start, page_end, GFP_NOFS); + ordered = btrfs_lookup_ordered_extent(page->mapping->host, + page_offset(page)); + if (ordered) { + /* + * IO on this page will never be started, so we need + * to account for any ordered extents now + */ + clear_extent_bit(tree, page_start, page_end, + EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_LOCKED, 1, 0, GFP_NOFS); + btrfs_finish_ordered_io(page->mapping->host, + page_start, page_end); + btrfs_put_ordered_extent(ordered); + lock_extent(tree, page_start, page_end, GFP_NOFS); + } + clear_extent_bit(tree, page_start, page_end, + EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_ORDERED, + 1, 1, GFP_NOFS); + __btrfs_releasepage(page, GFP_NOFS); + + ClearPageChecked(page); + if (PagePrivate(page)) { + ClearPagePrivate(page); + set_page_private(page, 0); + page_cache_release(page); + } +} + +/* + * btrfs_page_mkwrite() is not allowed to change the file size as it gets + * called from a page fault handler when a page is first dirtied. Hence we must + * be careful to check for EOF conditions here. We set the page up correctly + * for a written page which means we get ENOSPC checking when writing into + * holes and correct delalloc and unwritten extent mapping on filesystems that + * support these features. + * + * We are not allowed to take the i_mutex here so we have to play games to + * protect against truncate races as the page could now be beyond EOF. Because + * vmtruncate() writes the inode size before removing pages, once we have the + * page lock we can determine safely if the page is beyond EOF. If it is not + * beyond EOF, then the page is guaranteed safe against truncation until we + * unlock the page. + */ +int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page) +{ + struct inode *inode = fdentry(vma->vm_file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + char *kaddr; + unsigned long zero_start; + loff_t size; + int ret; + u64 page_start; + u64 page_end; + + ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0); + if (ret) + goto out; + + ret = -EINVAL; +again: + lock_page(page); + size = i_size_read(inode); + page_start = page_offset(page); + page_end = page_start + PAGE_CACHE_SIZE - 1; + + if ((page->mapping != inode->i_mapping) || + (page_start >= size)) { + /* page got truncated out from underneath us */ + goto out_unlock; + } + wait_on_page_writeback(page); + + lock_extent(io_tree, page_start, page_end, GFP_NOFS); + set_page_extent_mapped(page); + + /* + * we can't set the delalloc bits if there are pending ordered + * extents. Drop our locks and wait for them to finish + */ + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + btrfs_set_extent_delalloc(inode, page_start, page_end); + ret = 0; + + /* page is wholly or partially inside EOF */ + if (page_start + PAGE_CACHE_SIZE > size) + zero_start = size & ~PAGE_CACHE_MASK; + else + zero_start = PAGE_CACHE_SIZE; + + if (zero_start != PAGE_CACHE_SIZE) { + kaddr = kmap(page); + memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); + flush_dcache_page(page); + kunmap(page); + } + ClearPageChecked(page); + set_page_dirty(page); + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + +out_unlock: + unlock_page(page); +out: + return ret; +} + +static void btrfs_truncate(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + struct btrfs_trans_handle *trans; + unsigned long nr; + u64 mask = root->sectorsize - 1; + + if (!S_ISREG(inode->i_mode)) + return; + if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) + return; + + btrfs_truncate_page(inode->i_mapping, inode->i_size); + btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1); + + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, inode); + btrfs_i_size_write(inode, inode->i_size); + + ret = btrfs_orphan_add(trans, inode); + if (ret) + goto out; + /* FIXME, add redo link to tree so we don't leak on crash */ + ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, + BTRFS_EXTENT_DATA_KEY); + btrfs_update_inode(trans, root, inode); + + ret = btrfs_orphan_del(trans, inode); + BUG_ON(ret); + +out: + nr = trans->blocks_used; + ret = btrfs_end_transaction_throttle(trans, root); + BUG_ON(ret); + btrfs_btree_balance_dirty(root, nr); +} + +/* + * create a new subvolume directory/inode (helper for the ioctl). + */ +int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, + struct btrfs_root *new_root, struct dentry *dentry, + u64 new_dirid, u64 alloc_hint) +{ + struct inode *inode; + int error; + u64 index = 0; + + inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid, + new_dirid, alloc_hint, S_IFDIR | 0700, &index); + if (IS_ERR(inode)) + return PTR_ERR(inode); + inode->i_op = &btrfs_dir_inode_operations; + inode->i_fop = &btrfs_dir_file_operations; + + inode->i_nlink = 1; + btrfs_i_size_write(inode, 0); + + error = btrfs_update_inode(trans, new_root, inode); + if (error) + return error; + + d_instantiate(dentry, inode); + return 0; +} + +/* helper function for file defrag and space balancing. This + * forces readahead on a given range of bytes in an inode + */ +unsigned long btrfs_force_ra(struct address_space *mapping, + struct file_ra_state *ra, struct file *file, + pgoff_t offset, pgoff_t last_index) +{ + pgoff_t req_size = last_index - offset + 1; + + page_cache_sync_readahead(mapping, ra, file, offset, req_size); + return offset + req_size; +} + +struct inode *btrfs_alloc_inode(struct super_block *sb) +{ + struct btrfs_inode *ei; + + ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); + if (!ei) + return NULL; + ei->last_trans = 0; + ei->logged_trans = 0; + btrfs_ordered_inode_tree_init(&ei->ordered_tree); + ei->i_acl = BTRFS_ACL_NOT_CACHED; + ei->i_default_acl = BTRFS_ACL_NOT_CACHED; + INIT_LIST_HEAD(&ei->i_orphan); + return &ei->vfs_inode; +} + +void btrfs_destroy_inode(struct inode *inode) +{ + struct btrfs_ordered_extent *ordered; + WARN_ON(!list_empty(&inode->i_dentry)); + WARN_ON(inode->i_data.nrpages); + + if (BTRFS_I(inode)->i_acl && + BTRFS_I(inode)->i_acl != BTRFS_ACL_NOT_CACHED) + posix_acl_release(BTRFS_I(inode)->i_acl); + if (BTRFS_I(inode)->i_default_acl && + BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED) + posix_acl_release(BTRFS_I(inode)->i_default_acl); + + spin_lock(&BTRFS_I(inode)->root->list_lock); + if (!list_empty(&BTRFS_I(inode)->i_orphan)) { + printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan" + " list\n", inode->i_ino); + dump_stack(); + } + spin_unlock(&BTRFS_I(inode)->root->list_lock); + + while (1) { + ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); + if (!ordered) + break; + else { + printk(KERN_ERR "btrfs found ordered " + "extent %llu %llu on inode cleanup\n", + (unsigned long long)ordered->file_offset, + (unsigned long long)ordered->len); + btrfs_remove_ordered_extent(inode, ordered); + btrfs_put_ordered_extent(ordered); + btrfs_put_ordered_extent(ordered); + } + } + btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); + kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); +} + +static void init_once(void *foo) +{ + struct btrfs_inode *ei = (struct btrfs_inode *) foo; + + inode_init_once(&ei->vfs_inode); +} + +void btrfs_destroy_cachep(void) +{ + if (btrfs_inode_cachep) + kmem_cache_destroy(btrfs_inode_cachep); + if (btrfs_trans_handle_cachep) + kmem_cache_destroy(btrfs_trans_handle_cachep); + if (btrfs_transaction_cachep) + kmem_cache_destroy(btrfs_transaction_cachep); + if (btrfs_bit_radix_cachep) + kmem_cache_destroy(btrfs_bit_radix_cachep); + if (btrfs_path_cachep) + kmem_cache_destroy(btrfs_path_cachep); +} + +struct kmem_cache *btrfs_cache_create(const char *name, size_t size, + unsigned long extra_flags, + void (*ctor)(void *)) +{ + return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT | + SLAB_MEM_SPREAD | extra_flags), ctor); +} + +int btrfs_init_cachep(void) +{ + btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache", + sizeof(struct btrfs_inode), + 0, init_once); + if (!btrfs_inode_cachep) + goto fail; + btrfs_trans_handle_cachep = + btrfs_cache_create("btrfs_trans_handle_cache", + sizeof(struct btrfs_trans_handle), + 0, NULL); + if (!btrfs_trans_handle_cachep) + goto fail; + btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache", + sizeof(struct btrfs_transaction), + 0, NULL); + if (!btrfs_transaction_cachep) + goto fail; + btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache", + sizeof(struct btrfs_path), + 0, NULL); + if (!btrfs_path_cachep) + goto fail; + btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256, + SLAB_DESTROY_BY_RCU, NULL); + if (!btrfs_bit_radix_cachep) + goto fail; + return 0; +fail: + btrfs_destroy_cachep(); + return -ENOMEM; +} + +static int btrfs_getattr(struct vfsmount *mnt, + struct dentry *dentry, struct kstat *stat) +{ + struct inode *inode = dentry->d_inode; + generic_fillattr(inode, stat); + stat->dev = BTRFS_I(inode)->root->anon_super.s_dev; + stat->blksize = PAGE_CACHE_SIZE; + stat->blocks = (inode_get_bytes(inode) + + BTRFS_I(inode)->delalloc_bytes) >> 9; + return 0; +} + +static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(old_dir)->root; + struct inode *new_inode = new_dentry->d_inode; + struct inode *old_inode = old_dentry->d_inode; + struct timespec ctime = CURRENT_TIME; + u64 index = 0; + int ret; + + /* we're not allowed to rename between subvolumes */ + if (BTRFS_I(old_inode)->root->root_key.objectid != + BTRFS_I(new_dir)->root->root_key.objectid) + return -EXDEV; + + if (S_ISDIR(old_inode->i_mode) && new_inode && + new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) { + return -ENOTEMPTY; + } + + /* to rename a snapshot or subvolume, we need to juggle the + * backrefs. This isn't coded yet + */ + if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) + return -EXDEV; + + ret = btrfs_check_free_space(root, 1, 0); + if (ret) + goto out_unlock; + + trans = btrfs_start_transaction(root, 1); + + btrfs_set_trans_block_group(trans, new_dir); + + btrfs_inc_nlink(old_dentry->d_inode); + old_dir->i_ctime = old_dir->i_mtime = ctime; + new_dir->i_ctime = new_dir->i_mtime = ctime; + old_inode->i_ctime = ctime; + + ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode, + old_dentry->d_name.name, + old_dentry->d_name.len); + if (ret) + goto out_fail; + + if (new_inode) { + new_inode->i_ctime = CURRENT_TIME; + ret = btrfs_unlink_inode(trans, root, new_dir, + new_dentry->d_inode, + new_dentry->d_name.name, + new_dentry->d_name.len); + if (ret) + goto out_fail; + if (new_inode->i_nlink == 0) { + ret = btrfs_orphan_add(trans, new_dentry->d_inode); + if (ret) + goto out_fail; + } + + } + ret = btrfs_set_inode_index(new_dir, &index); + if (ret) + goto out_fail; + + ret = btrfs_add_link(trans, new_dentry->d_parent->d_inode, + old_inode, new_dentry->d_name.name, + new_dentry->d_name.len, 1, index); + if (ret) + goto out_fail; + +out_fail: + btrfs_end_transaction_throttle(trans, root); +out_unlock: + return ret; +} + +/* + * some fairly slow code that needs optimization. This walks the list + * of all the inodes with pending delalloc and forces them to disk. + */ +int btrfs_start_delalloc_inodes(struct btrfs_root *root) +{ + struct list_head *head = &root->fs_info->delalloc_inodes; + struct btrfs_inode *binode; + struct inode *inode; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + spin_lock(&root->fs_info->delalloc_lock); + while (!list_empty(head)) { + binode = list_entry(head->next, struct btrfs_inode, + delalloc_inodes); + inode = igrab(&binode->vfs_inode); + if (!inode) + list_del_init(&binode->delalloc_inodes); + spin_unlock(&root->fs_info->delalloc_lock); + if (inode) { + filemap_flush(inode->i_mapping); + iput(inode); + } + cond_resched(); + spin_lock(&root->fs_info->delalloc_lock); + } + spin_unlock(&root->fs_info->delalloc_lock); + + /* the filemap_flush will queue IO into the worker threads, but + * we have to make sure the IO is actually started and that + * ordered extents get created before we return + */ + atomic_inc(&root->fs_info->async_submit_draining); + while (atomic_read(&root->fs_info->nr_async_submits) || + atomic_read(&root->fs_info->async_delalloc_pages)) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->nr_async_submits) == 0 && + atomic_read(&root->fs_info->async_delalloc_pages) == 0)); + } + atomic_dec(&root->fs_info->async_submit_draining); + return 0; +} + +static int btrfs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_path *path; + struct btrfs_key key; + struct inode *inode = NULL; + int err; + int drop_inode = 0; + u64 objectid; + u64 index = 0 ; + int name_len; + int datasize; + unsigned long ptr; + struct btrfs_file_extent_item *ei; + struct extent_buffer *leaf; + unsigned long nr = 0; + + name_len = strlen(symname) + 1; + if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) + return -ENAMETOOLONG; + + err = btrfs_check_free_space(root, 1, 0); + if (err) + goto out_fail; + + trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, dir); + + err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); + if (err) { + err = -ENOSPC; + goto out_unlock; + } + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, + dentry->d_parent->d_inode->i_ino, objectid, + BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO, + &index); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_unlock; + + err = btrfs_init_acl(inode, dir); + if (err) { + drop_inode = 1; + goto out_unlock; + } + + btrfs_set_trans_block_group(trans, inode); + err = btrfs_add_nondir(trans, dentry, inode, 0, index); + if (err) + drop_inode = 1; + else { + inode->i_mapping->a_ops = &btrfs_aops; + inode->i_mapping->backing_dev_info = &root->fs_info->bdi; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + } + dir->i_sb->s_dirt = 1; + btrfs_update_inode_block_group(trans, inode); + btrfs_update_inode_block_group(trans, dir); + if (drop_inode) + goto out_unlock; + + path = btrfs_alloc_path(); + BUG_ON(!path); + key.objectid = inode->i_ino; + key.offset = 0; + btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); + datasize = btrfs_file_extent_calc_inline_size(name_len); + err = btrfs_insert_empty_item(trans, root, path, &key, + datasize); + if (err) { + drop_inode = 1; + goto out_unlock; + } + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, ei, trans->transid); + btrfs_set_file_extent_type(leaf, ei, + BTRFS_FILE_EXTENT_INLINE); + btrfs_set_file_extent_encryption(leaf, ei, 0); + btrfs_set_file_extent_compression(leaf, ei, 0); + btrfs_set_file_extent_other_encoding(leaf, ei, 0); + btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); + + ptr = btrfs_file_extent_inline_start(ei); + write_extent_buffer(leaf, symname, ptr, name_len); + btrfs_mark_buffer_dirty(leaf); + btrfs_free_path(path); + + inode->i_op = &btrfs_symlink_inode_operations; + inode->i_mapping->a_ops = &btrfs_symlink_aops; + inode->i_mapping->backing_dev_info = &root->fs_info->bdi; + inode_set_bytes(inode, name_len); + btrfs_i_size_write(inode, name_len - 1); + err = btrfs_update_inode(trans, root, inode); + if (err) + drop_inode = 1; + +out_unlock: + nr = trans->blocks_used; + btrfs_end_transaction_throttle(trans, root); +out_fail: + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(root, nr); + return err; +} + +static int prealloc_file_range(struct inode *inode, u64 start, u64 end, + u64 alloc_hint, int mode) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key ins; + u64 alloc_size; + u64 cur_offset = start; + u64 num_bytes = end - start; + int ret = 0; + + trans = btrfs_join_transaction(root, 1); + BUG_ON(!trans); + btrfs_set_trans_block_group(trans, inode); + + while (num_bytes > 0) { + alloc_size = min(num_bytes, root->fs_info->max_extent); + ret = btrfs_reserve_extent(trans, root, alloc_size, + root->sectorsize, 0, alloc_hint, + (u64)-1, &ins, 1); + if (ret) { + WARN_ON(1); + goto out; + } + ret = insert_reserved_file_extent(trans, inode, + cur_offset, ins.objectid, + ins.offset, ins.offset, + ins.offset, 0, 0, 0, + BTRFS_FILE_EXTENT_PREALLOC); + BUG_ON(ret); + num_bytes -= ins.offset; + cur_offset += ins.offset; + alloc_hint = ins.objectid + ins.offset; + } +out: + if (cur_offset > start) { + inode->i_ctime = CURRENT_TIME; + btrfs_set_flag(inode, PREALLOC); + if (!(mode & FALLOC_FL_KEEP_SIZE) && + cur_offset > i_size_read(inode)) + btrfs_i_size_write(inode, cur_offset); + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); + } + + btrfs_end_transaction(trans, root); + return ret; +} + +static long btrfs_fallocate(struct inode *inode, int mode, + loff_t offset, loff_t len) +{ + u64 cur_offset; + u64 last_byte; + u64 alloc_start; + u64 alloc_end; + u64 alloc_hint = 0; + u64 mask = BTRFS_I(inode)->root->sectorsize - 1; + struct extent_map *em; + int ret; + + alloc_start = offset & ~mask; + alloc_end = (offset + len + mask) & ~mask; + + mutex_lock(&inode->i_mutex); + if (alloc_start > inode->i_size) { + ret = btrfs_cont_expand(inode, alloc_start); + if (ret) + goto out; + } + + while (1) { + struct btrfs_ordered_extent *ordered; + lock_extent(&BTRFS_I(inode)->io_tree, alloc_start, + alloc_end - 1, GFP_NOFS); + ordered = btrfs_lookup_first_ordered_extent(inode, + alloc_end - 1); + if (ordered && + ordered->file_offset + ordered->len > alloc_start && + ordered->file_offset < alloc_end) { + btrfs_put_ordered_extent(ordered); + unlock_extent(&BTRFS_I(inode)->io_tree, + alloc_start, alloc_end - 1, GFP_NOFS); + btrfs_wait_ordered_range(inode, alloc_start, + alloc_end - alloc_start); + } else { + if (ordered) + btrfs_put_ordered_extent(ordered); + break; + } + } + + cur_offset = alloc_start; + while (1) { + em = btrfs_get_extent(inode, NULL, 0, cur_offset, + alloc_end - cur_offset, 0); + BUG_ON(IS_ERR(em) || !em); + last_byte = min(extent_map_end(em), alloc_end); + last_byte = (last_byte + mask) & ~mask; + if (em->block_start == EXTENT_MAP_HOLE) { + ret = prealloc_file_range(inode, cur_offset, + last_byte, alloc_hint, mode); + if (ret < 0) { + free_extent_map(em); + break; + } + } + if (em->block_start <= EXTENT_MAP_LAST_BYTE) + alloc_hint = em->block_start; + free_extent_map(em); + + cur_offset = last_byte; + if (cur_offset >= alloc_end) { + ret = 0; + break; + } + } + unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, alloc_end - 1, + GFP_NOFS); +out: + mutex_unlock(&inode->i_mutex); + return ret; +} + +static int btrfs_set_page_dirty(struct page *page) +{ + return __set_page_dirty_nobuffers(page); +} + +static int btrfs_permission(struct inode *inode, int mask) +{ + if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE)) + return -EACCES; + return generic_permission(inode, mask, btrfs_check_acl); +} + +static struct inode_operations btrfs_dir_inode_operations = { + .getattr = btrfs_getattr, + .lookup = btrfs_lookup, + .create = btrfs_create, + .unlink = btrfs_unlink, + .link = btrfs_link, + .mkdir = btrfs_mkdir, + .rmdir = btrfs_rmdir, + .rename = btrfs_rename, + .symlink = btrfs_symlink, + .setattr = btrfs_setattr, + .mknod = btrfs_mknod, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, + .permission = btrfs_permission, +}; +static struct inode_operations btrfs_dir_ro_inode_operations = { + .lookup = btrfs_lookup, + .permission = btrfs_permission, +}; +static struct file_operations btrfs_dir_file_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .readdir = btrfs_real_readdir, + .unlocked_ioctl = btrfs_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = btrfs_ioctl, +#endif + .release = btrfs_release_file, + .fsync = btrfs_sync_file, +}; + +static struct extent_io_ops btrfs_extent_io_ops = { + .fill_delalloc = run_delalloc_range, + .submit_bio_hook = btrfs_submit_bio_hook, + .merge_bio_hook = btrfs_merge_bio_hook, + .readpage_end_io_hook = btrfs_readpage_end_io_hook, + .writepage_end_io_hook = btrfs_writepage_end_io_hook, + .writepage_start_hook = btrfs_writepage_start_hook, + .readpage_io_failed_hook = btrfs_io_failed_hook, + .set_bit_hook = btrfs_set_bit_hook, + .clear_bit_hook = btrfs_clear_bit_hook, +}; + +static struct address_space_operations btrfs_aops = { + .readpage = btrfs_readpage, + .writepage = btrfs_writepage, + .writepages = btrfs_writepages, + .readpages = btrfs_readpages, + .sync_page = block_sync_page, + .bmap = btrfs_bmap, + .direct_IO = btrfs_direct_IO, + .invalidatepage = btrfs_invalidatepage, + .releasepage = btrfs_releasepage, + .set_page_dirty = btrfs_set_page_dirty, +}; + +static struct address_space_operations btrfs_symlink_aops = { + .readpage = btrfs_readpage, + .writepage = btrfs_writepage, + .invalidatepage = btrfs_invalidatepage, + .releasepage = btrfs_releasepage, +}; + +static struct inode_operations btrfs_file_inode_operations = { + .truncate = btrfs_truncate, + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, + .permission = btrfs_permission, + .fallocate = btrfs_fallocate, +}; +static struct inode_operations btrfs_special_inode_operations = { + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .permission = btrfs_permission, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, +}; +static struct inode_operations btrfs_symlink_inode_operations = { + .readlink = generic_readlink, + .follow_link = page_follow_link_light, + .put_link = page_put_link, + .permission = btrfs_permission, +}; 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