/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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; unsigned long flags; int ret = 0; spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); 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_irqrestore(&root->fs_info->delalloc_lock, flags); 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 int noinline 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); inode_add_bytes(inode, size); 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; printk("got bad ret %d\n", 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; 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; 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); actual_end = min_t(u64, i_size_read(inode), end + 1); 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; 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]); } if (pages) 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; 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, i_size_read(inode), 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); if (ret) { BUG(); } 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 (disk_num_bytes < cur_alloc_size) { printk("num_bytes %Lu cur_alloc %Lu\n", 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; } /* * 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; 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) { struct btrfs_block_group_cache *block_group; 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 (btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) goto out_check; if (disk_bytenr == 0) goto out_check; if (extent_type == BTRFS_FILE_EXTENT_REG && !force) goto out_check; if (btrfs_cross_ref_exist(trans, root, disk_bytenr)) goto out_check; block_group = btrfs_lookup_block_group(root->fs_info, disk_bytenr); if (!block_group || block_group->ro) goto out_check; disk_bytenr += btrfs_file_extent_offset(leaf, fi); 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; } disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; 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) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret; if (btrfs_test_opt(root, NODATACOW) || 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) { unsigned long flags; if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); 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_irqrestore(&root->fs_info->delalloc_lock, flags); } 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) { if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; unsigned long flags; spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); if (end - start + 1 > root->fs_info->delalloc_bytes) { printk("warning: delalloc account %Lu %Lu\n", end - start + 1, 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_irqrestore(&root->fs_info->delalloc_lock, flags); } 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); 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; ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); BUG_ON(ret); skip_sum = btrfs_test_opt(root, NODATASUM) || btrfs_test_flag(inode, NODATASUM); 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); goto mapit; } else if (!skip_sum) { /* 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, inode, 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; 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; unsigned long bio_flags = 0; 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; 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)) 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_irq(&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_irq(&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, 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; unsigned long flags; if (btrfs_test_opt(root, NODATASUM) || btrfs_test_flag(inode, NODATASUM)) return 0; if (state && state->start == start) { private = state->private; ret = 0; } else { ret = get_state_private(io_tree, start, &private); } local_irq_save(flags); kaddr = kmap_atomic(page, KM_IRQ0); 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_IRQ0); local_irq_restore(flags); /* 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("btrfs csum failed ino %lu off %llu csum %u private %Lu\n", page->mapping->host->i_ino, (unsigned long long)start, csum, private); memset(kaddr + offset, 1, end - start + 1); flush_dcache_page(page); kunmap_atomic(kaddr, KM_IRQ0); local_irq_restore(flags); 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); 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; alloc_group_block = btrfs_inode_block_group(leaf, inode_item); BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info, alloc_group_block); BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); if (!BTRFS_I(inode)->block_group) { BTRFS_I(inode)->block_group = btrfs_find_block_group(root, NULL, 0, BTRFS_BLOCK_GROUP_METADATA, 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_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->key.objectid); } /* * copy everything in the in-memory inode into the btree. */ int noinline 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("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; } /* * 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; } /* * 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); ret = drop_csum_leaves(trans, root, path, inode, new_size); BUG_ON(ret); 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 (found_type == BTRFS_CSUM_ITEM_KEY) { ret = btrfs_csum_truncate(trans, root, path, new_size); BUG_ON(ret); } 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_CSUM_ITEM_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 { printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot); } } 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_start_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->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)->csum_mutex); 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, struct btrfs_block_group_cache *group, int mode, u64 *index) { struct inode *inode; struct btrfs_inode_item *inode_item; struct btrfs_block_group_cache *new_inode_group; 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; new_inode_group = btrfs_find_block_group(root, group, 0, BTRFS_BLOCK_GROUP_METADATA, owner); if (!new_inode_group) { printk("find_block group failed\n"); new_inode_group = group; } BTRFS_I(inode)->block_group = new_inode_group; 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("unkknown 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("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, 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; printk("failing to insert %Lu %Lu\n", start, len); 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); } /* * Invalidate a single dcache entry at the root of the filesystem. * Needed after creation of snapshot or subvolume. */ static void btrfs_invalidate_dcache_root(struct inode *dir, char *name, int namelen) { struct dentry *alias, *entry; struct qstr qstr; alias = d_find_alias(dir); if (alias) { qstr.name = name; qstr.len = namelen; /* change me if btrfs ever gets a d_hash operation */ qstr.hash = full_name_hash(qstr.name, qstr.len); entry = d_lookup(alias, &qstr); dput(alias); if (entry) { d_invalidate(entry); dput(entry); } } } /* * create a new subvolume directory/inode (helper for the ioctl). */ int btrfs_create_subvol_root(struct btrfs_root *new_root, struct dentry *dentry, struct btrfs_trans_handle *trans, u64 new_dirid, struct btrfs_block_group_cache *block_group) { struct inode *inode; int error; u64 index = 0; inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid, new_dirid, block_group, 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("found ordered extent %Lu %Lu\n", ordered->file_offset, 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; unsigned long flags; if (root->fs_info->sb->s_flags & MS_RDONLY) return -EROFS; spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); 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_irqrestore(&root->fs_info->delalloc_lock, flags); if (inode) { filemap_flush(inode->i_mapping); iput(inode); } cond_resched(); spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); } spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags); /* 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, };