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-rw-r--r--fs/btrfs/inode.c5035
1 files changed, 5035 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
new file mode 100644
index 000000000000..8adfe059ab41
--- /dev/null
+++ b/fs/btrfs/inode.c
@@ -0,0 +1,5035 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/bit_spinlock.h>
+#include <linux/version.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/falloc.h>
+#include "compat.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "ordered-data.h"
+#include "xattr.h"
+#include "tree-log.h"
+#include "ref-cache.h"
+#include "compression.h"
+
+struct btrfs_iget_args {
+ u64 ino;
+ struct btrfs_root *root;
+};
+
+static struct inode_operations btrfs_dir_inode_operations;
+static struct inode_operations btrfs_symlink_inode_operations;
+static struct inode_operations btrfs_dir_ro_inode_operations;
+static struct inode_operations btrfs_special_inode_operations;
+static struct inode_operations btrfs_file_inode_operations;
+static struct address_space_operations btrfs_aops;
+static struct address_space_operations btrfs_symlink_aops;
+static struct file_operations btrfs_dir_file_operations;
+static struct extent_io_ops btrfs_extent_io_ops;
+
+static struct kmem_cache *btrfs_inode_cachep;
+struct kmem_cache *btrfs_trans_handle_cachep;
+struct kmem_cache *btrfs_transaction_cachep;
+struct kmem_cache *btrfs_bit_radix_cachep;
+struct kmem_cache *btrfs_path_cachep;
+
+#define S_SHIFT 12
+static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+ [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
+ [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
+ [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
+ [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
+ [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
+ [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
+ [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
+};
+
+static void btrfs_truncate(struct inode *inode);
+static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
+static noinline int cow_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written, int unlock);
+
+/*
+ * a very lame attempt at stopping writes when the FS is 85% full. There
+ * are countless ways this is incorrect, but it is better than nothing.
+ */
+int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
+ int for_del)
+{
+ u64 total;
+ u64 used;
+ u64 thresh;
+ int ret = 0;
+
+ spin_lock(&root->fs_info->delalloc_lock);
+ total = btrfs_super_total_bytes(&root->fs_info->super_copy);
+ used = btrfs_super_bytes_used(&root->fs_info->super_copy);
+ if (for_del)
+ thresh = total * 90;
+ else
+ thresh = total * 85;
+
+ do_div(thresh, 100);
+
+ if (used + root->fs_info->delalloc_bytes + num_required > thresh)
+ ret = -ENOSPC;
+ spin_unlock(&root->fs_info->delalloc_lock);
+ return ret;
+}
+
+/*
+ * this does all the hard work for inserting an inline extent into
+ * the btree. The caller should have done a btrfs_drop_extents so that
+ * no overlapping inline items exist in the btree
+ */
+static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ u64 start, size_t size, size_t compressed_size,
+ struct page **compressed_pages)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct page *page = NULL;
+ char *kaddr;
+ unsigned long ptr;
+ struct btrfs_file_extent_item *ei;
+ int err = 0;
+ int ret;
+ size_t cur_size = size;
+ size_t datasize;
+ unsigned long offset;
+ int use_compress = 0;
+
+ if (compressed_size && compressed_pages) {
+ use_compress = 1;
+ cur_size = compressed_size;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ btrfs_set_trans_block_group(trans, inode);
+
+ key.objectid = inode->i_ino;
+ key.offset = start;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+ datasize = btrfs_file_extent_calc_inline_size(cur_size);
+
+ inode_add_bytes(inode, size);
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ BUG_ON(ret);
+ if (ret) {
+ err = ret;
+ goto fail;
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, ei, trans->transid);
+ btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
+ btrfs_set_file_extent_encryption(leaf, ei, 0);
+ btrfs_set_file_extent_other_encoding(leaf, ei, 0);
+ btrfs_set_file_extent_ram_bytes(leaf, ei, size);
+ ptr = btrfs_file_extent_inline_start(ei);
+
+ if (use_compress) {
+ struct page *cpage;
+ int i = 0;
+ while (compressed_size > 0) {
+ cpage = compressed_pages[i];
+ cur_size = min_t(unsigned long, compressed_size,
+ PAGE_CACHE_SIZE);
+
+ kaddr = kmap(cpage);
+ write_extent_buffer(leaf, kaddr, ptr, cur_size);
+ kunmap(cpage);
+
+ i++;
+ ptr += cur_size;
+ compressed_size -= cur_size;
+ }
+ btrfs_set_file_extent_compression(leaf, ei,
+ BTRFS_COMPRESS_ZLIB);
+ } else {
+ page = find_get_page(inode->i_mapping,
+ start >> PAGE_CACHE_SHIFT);
+ btrfs_set_file_extent_compression(leaf, ei, 0);
+ kaddr = kmap_atomic(page, KM_USER0);
+ offset = start & (PAGE_CACHE_SIZE - 1);
+ write_extent_buffer(leaf, kaddr + offset, ptr, size);
+ kunmap_atomic(kaddr, KM_USER0);
+ page_cache_release(page);
+ }
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+
+ BTRFS_I(inode)->disk_i_size = inode->i_size;
+ btrfs_update_inode(trans, root, inode);
+ return 0;
+fail:
+ btrfs_free_path(path);
+ return err;
+}
+
+
+/*
+ * conditionally insert an inline extent into the file. This
+ * does the checks required to make sure the data is small enough
+ * to fit as an inline extent.
+ */
+static int cow_file_range_inline(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode, u64 start, u64 end,
+ size_t compressed_size,
+ struct page **compressed_pages)
+{
+ u64 isize = i_size_read(inode);
+ u64 actual_end = min(end + 1, isize);
+ u64 inline_len = actual_end - start;
+ u64 aligned_end = (end + root->sectorsize - 1) &
+ ~((u64)root->sectorsize - 1);
+ u64 hint_byte;
+ u64 data_len = inline_len;
+ int ret;
+
+ if (compressed_size)
+ data_len = compressed_size;
+
+ if (start > 0 ||
+ actual_end >= PAGE_CACHE_SIZE ||
+ data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
+ (!compressed_size &&
+ (actual_end & (root->sectorsize - 1)) == 0) ||
+ end + 1 < isize ||
+ data_len > root->fs_info->max_inline) {
+ return 1;
+ }
+
+ ret = btrfs_drop_extents(trans, root, inode, start,
+ aligned_end, start, &hint_byte);
+ BUG_ON(ret);
+
+ if (isize > actual_end)
+ inline_len = min_t(u64, isize, actual_end);
+ ret = insert_inline_extent(trans, root, inode, start,
+ inline_len, compressed_size,
+ compressed_pages);
+ BUG_ON(ret);
+ btrfs_drop_extent_cache(inode, start, aligned_end, 0);
+ return 0;
+}
+
+struct async_extent {
+ u64 start;
+ u64 ram_size;
+ u64 compressed_size;
+ struct page **pages;
+ unsigned long nr_pages;
+ struct list_head list;
+};
+
+struct async_cow {
+ struct inode *inode;
+ struct btrfs_root *root;
+ struct page *locked_page;
+ u64 start;
+ u64 end;
+ struct list_head extents;
+ struct btrfs_work work;
+};
+
+static noinline int add_async_extent(struct async_cow *cow,
+ u64 start, u64 ram_size,
+ u64 compressed_size,
+ struct page **pages,
+ unsigned long nr_pages)
+{
+ struct async_extent *async_extent;
+
+ async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
+ async_extent->start = start;
+ async_extent->ram_size = ram_size;
+ async_extent->compressed_size = compressed_size;
+ async_extent->pages = pages;
+ async_extent->nr_pages = nr_pages;
+ list_add_tail(&async_extent->list, &cow->extents);
+ return 0;
+}
+
+/*
+ * we create compressed extents in two phases. The first
+ * phase compresses a range of pages that have already been
+ * locked (both pages and state bits are locked).
+ *
+ * This is done inside an ordered work queue, and the compression
+ * is spread across many cpus. The actual IO submission is step
+ * two, and the ordered work queue takes care of making sure that
+ * happens in the same order things were put onto the queue by
+ * writepages and friends.
+ *
+ * If this code finds it can't get good compression, it puts an
+ * entry onto the work queue to write the uncompressed bytes. This
+ * makes sure that both compressed inodes and uncompressed inodes
+ * are written in the same order that pdflush sent them down.
+ */
+static noinline int compress_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end,
+ struct async_cow *async_cow,
+ int *num_added)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ u64 num_bytes;
+ u64 orig_start;
+ u64 disk_num_bytes;
+ u64 blocksize = root->sectorsize;
+ u64 actual_end;
+ u64 isize = i_size_read(inode);
+ int ret = 0;
+ struct page **pages = NULL;
+ unsigned long nr_pages;
+ unsigned long nr_pages_ret = 0;
+ unsigned long total_compressed = 0;
+ unsigned long total_in = 0;
+ unsigned long max_compressed = 128 * 1024;
+ unsigned long max_uncompressed = 128 * 1024;
+ int i;
+ int will_compress;
+
+ orig_start = start;
+
+ actual_end = min_t(u64, isize, end + 1);
+again:
+ will_compress = 0;
+ nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
+ nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
+
+ total_compressed = actual_end - start;
+
+ /* we want to make sure that amount of ram required to uncompress
+ * an extent is reasonable, so we limit the total size in ram
+ * of a compressed extent to 128k. This is a crucial number
+ * because it also controls how easily we can spread reads across
+ * cpus for decompression.
+ *
+ * We also want to make sure the amount of IO required to do
+ * a random read is reasonably small, so we limit the size of
+ * a compressed extent to 128k.
+ */
+ total_compressed = min(total_compressed, max_uncompressed);
+ num_bytes = (end - start + blocksize) & ~(blocksize - 1);
+ num_bytes = max(blocksize, num_bytes);
+ disk_num_bytes = num_bytes;
+ total_in = 0;
+ ret = 0;
+
+ /*
+ * we do compression for mount -o compress and when the
+ * inode has not been flagged as nocompress. This flag can
+ * change at any time if we discover bad compression ratios.
+ */
+ if (!btrfs_test_flag(inode, NOCOMPRESS) &&
+ btrfs_test_opt(root, COMPRESS)) {
+ WARN_ON(pages);
+ pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
+
+ ret = btrfs_zlib_compress_pages(inode->i_mapping, start,
+ total_compressed, pages,
+ nr_pages, &nr_pages_ret,
+ &total_in,
+ &total_compressed,
+ max_compressed);
+
+ if (!ret) {
+ unsigned long offset = total_compressed &
+ (PAGE_CACHE_SIZE - 1);
+ struct page *page = pages[nr_pages_ret - 1];
+ char *kaddr;
+
+ /* zero the tail end of the last page, we might be
+ * sending it down to disk
+ */
+ if (offset) {
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, 0,
+ PAGE_CACHE_SIZE - offset);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ will_compress = 1;
+ }
+ }
+ if (start == 0) {
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ /* lets try to make an inline extent */
+ if (ret || total_in < (actual_end - start)) {
+ /* we didn't compress the entire range, try
+ * to make an uncompressed inline extent.
+ */
+ ret = cow_file_range_inline(trans, root, inode,
+ start, end, 0, NULL);
+ } else {
+ /* try making a compressed inline extent */
+ ret = cow_file_range_inline(trans, root, inode,
+ start, end,
+ total_compressed, pages);
+ }
+ btrfs_end_transaction(trans, root);
+ if (ret == 0) {
+ /*
+ * inline extent creation worked, we don't need
+ * to create any more async work items. Unlock
+ * and free up our temp pages.
+ */
+ extent_clear_unlock_delalloc(inode,
+ &BTRFS_I(inode)->io_tree,
+ start, end, NULL, 1, 0,
+ 0, 1, 1, 1);
+ ret = 0;
+ goto free_pages_out;
+ }
+ }
+
+ if (will_compress) {
+ /*
+ * we aren't doing an inline extent round the compressed size
+ * up to a block size boundary so the allocator does sane
+ * things
+ */
+ total_compressed = (total_compressed + blocksize - 1) &
+ ~(blocksize - 1);
+
+ /*
+ * one last check to make sure the compression is really a
+ * win, compare the page count read with the blocks on disk
+ */
+ total_in = (total_in + PAGE_CACHE_SIZE - 1) &
+ ~(PAGE_CACHE_SIZE - 1);
+ if (total_compressed >= total_in) {
+ will_compress = 0;
+ } else {
+ disk_num_bytes = total_compressed;
+ num_bytes = total_in;
+ }
+ }
+ if (!will_compress && pages) {
+ /*
+ * the compression code ran but failed to make things smaller,
+ * free any pages it allocated and our page pointer array
+ */
+ for (i = 0; i < nr_pages_ret; i++) {
+ WARN_ON(pages[i]->mapping);
+ page_cache_release(pages[i]);
+ }
+ kfree(pages);
+ pages = NULL;
+ total_compressed = 0;
+ nr_pages_ret = 0;
+
+ /* flag the file so we don't compress in the future */
+ btrfs_set_flag(inode, NOCOMPRESS);
+ }
+ if (will_compress) {
+ *num_added += 1;
+
+ /* the async work queues will take care of doing actual
+ * allocation on disk for these compressed pages,
+ * and will submit them to the elevator.
+ */
+ add_async_extent(async_cow, start, num_bytes,
+ total_compressed, pages, nr_pages_ret);
+
+ if (start + num_bytes < end && start + num_bytes < actual_end) {
+ start += num_bytes;
+ pages = NULL;
+ cond_resched();
+ goto again;
+ }
+ } else {
+ /*
+ * No compression, but we still need to write the pages in
+ * the file we've been given so far. redirty the locked
+ * page if it corresponds to our extent and set things up
+ * for the async work queue to run cow_file_range to do
+ * the normal delalloc dance
+ */
+ if (page_offset(locked_page) >= start &&
+ page_offset(locked_page) <= end) {
+ __set_page_dirty_nobuffers(locked_page);
+ /* unlocked later on in the async handlers */
+ }
+ add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0);
+ *num_added += 1;
+ }
+
+out:
+ return 0;
+
+free_pages_out:
+ for (i = 0; i < nr_pages_ret; i++) {
+ WARN_ON(pages[i]->mapping);
+ page_cache_release(pages[i]);
+ }
+ kfree(pages);
+
+ goto out;
+}
+
+/*
+ * phase two of compressed writeback. This is the ordered portion
+ * of the code, which only gets called in the order the work was
+ * queued. We walk all the async extents created by compress_file_range
+ * and send them down to the disk.
+ */
+static noinline int submit_compressed_extents(struct inode *inode,
+ struct async_cow *async_cow)
+{
+ struct async_extent *async_extent;
+ u64 alloc_hint = 0;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key ins;
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_io_tree *io_tree;
+ int ret;
+
+ if (list_empty(&async_cow->extents))
+ return 0;
+
+ trans = btrfs_join_transaction(root, 1);
+
+ while (!list_empty(&async_cow->extents)) {
+ async_extent = list_entry(async_cow->extents.next,
+ struct async_extent, list);
+ list_del(&async_extent->list);
+
+ io_tree = &BTRFS_I(inode)->io_tree;
+
+ /* did the compression code fall back to uncompressed IO? */
+ if (!async_extent->pages) {
+ int page_started = 0;
+ unsigned long nr_written = 0;
+
+ lock_extent(io_tree, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, GFP_NOFS);
+
+ /* allocate blocks */
+ cow_file_range(inode, async_cow->locked_page,
+ async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ &page_started, &nr_written, 0);
+
+ /*
+ * if page_started, cow_file_range inserted an
+ * inline extent and took care of all the unlocking
+ * and IO for us. Otherwise, we need to submit
+ * all those pages down to the drive.
+ */
+ if (!page_started)
+ extent_write_locked_range(io_tree,
+ inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ btrfs_get_extent,
+ WB_SYNC_ALL);
+ kfree(async_extent);
+ cond_resched();
+ continue;
+ }
+
+ lock_extent(io_tree, async_extent->start,
+ async_extent->start + async_extent->ram_size - 1,
+ GFP_NOFS);
+ /*
+ * here we're doing allocation and writeback of the
+ * compressed pages
+ */
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+
+ ret = btrfs_reserve_extent(trans, root,
+ async_extent->compressed_size,
+ async_extent->compressed_size,
+ 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ BUG_ON(ret);
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = async_extent->start;
+ em->len = async_extent->ram_size;
+ em->orig_start = em->start;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+
+ while (1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+ }
+
+ ret = btrfs_add_ordered_extent(inode, async_extent->start,
+ ins.objectid,
+ async_extent->ram_size,
+ ins.offset,
+ BTRFS_ORDERED_COMPRESSED);
+ BUG_ON(ret);
+
+ btrfs_end_transaction(trans, root);
+
+ /*
+ * clear dirty, set writeback and unlock the pages.
+ */
+ extent_clear_unlock_delalloc(inode,
+ &BTRFS_I(inode)->io_tree,
+ async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ NULL, 1, 1, 0, 1, 1, 0);
+
+ ret = btrfs_submit_compressed_write(inode,
+ async_extent->start,
+ async_extent->ram_size,
+ ins.objectid,
+ ins.offset, async_extent->pages,
+ async_extent->nr_pages);
+
+ BUG_ON(ret);
+ trans = btrfs_join_transaction(root, 1);
+ alloc_hint = ins.objectid + ins.offset;
+ kfree(async_extent);
+ cond_resched();
+ }
+
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+/*
+ * when extent_io.c finds a delayed allocation range in the file,
+ * the call backs end up in this code. The basic idea is to
+ * allocate extents on disk for the range, and create ordered data structs
+ * in ram to track those extents.
+ *
+ * locked_page is the page that writepage had locked already. We use
+ * it to make sure we don't do extra locks or unlocks.
+ *
+ * *page_started is set to one if we unlock locked_page and do everything
+ * required to start IO on it. It may be clean and already done with
+ * IO when we return.
+ */
+static noinline int cow_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written,
+ int unlock)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ u64 alloc_hint = 0;
+ u64 num_bytes;
+ unsigned long ram_size;
+ u64 disk_num_bytes;
+ u64 cur_alloc_size;
+ u64 blocksize = root->sectorsize;
+ u64 actual_end;
+ u64 isize = i_size_read(inode);
+ struct btrfs_key ins;
+ struct extent_map *em;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ int ret = 0;
+
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ actual_end = min_t(u64, isize, end + 1);
+
+ num_bytes = (end - start + blocksize) & ~(blocksize - 1);
+ num_bytes = max(blocksize, num_bytes);
+ disk_num_bytes = num_bytes;
+ ret = 0;
+
+ if (start == 0) {
+ /* lets try to make an inline extent */
+ ret = cow_file_range_inline(trans, root, inode,
+ start, end, 0, NULL);
+ if (ret == 0) {
+ extent_clear_unlock_delalloc(inode,
+ &BTRFS_I(inode)->io_tree,
+ start, end, NULL, 1, 1,
+ 1, 1, 1, 1);
+ *nr_written = *nr_written +
+ (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
+ *page_started = 1;
+ ret = 0;
+ goto out;
+ }
+ }
+
+ BUG_ON(disk_num_bytes >
+ btrfs_super_total_bytes(&root->fs_info->super_copy));
+
+ btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
+
+ while (disk_num_bytes > 0) {
+ cur_alloc_size = min(disk_num_bytes, root->fs_info->max_extent);
+ ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
+ root->sectorsize, 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ BUG_ON(ret);
+
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = start;
+ em->orig_start = em->start;
+
+ ram_size = ins.offset;
+ em->len = ins.offset;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+
+ while (1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, start,
+ start + ram_size - 1, 0);
+ }
+
+ cur_alloc_size = ins.offset;
+ ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
+ ram_size, cur_alloc_size, 0);
+ BUG_ON(ret);
+
+ if (root->root_key.objectid ==
+ BTRFS_DATA_RELOC_TREE_OBJECTID) {
+ ret = btrfs_reloc_clone_csums(inode, start,
+ cur_alloc_size);
+ BUG_ON(ret);
+ }
+
+ if (disk_num_bytes < cur_alloc_size)
+ break;
+
+ /* we're not doing compressed IO, don't unlock the first
+ * page (which the caller expects to stay locked), don't
+ * clear any dirty bits and don't set any writeback bits
+ */
+ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
+ start, start + ram_size - 1,
+ locked_page, unlock, 1,
+ 1, 0, 0, 0);
+ disk_num_bytes -= cur_alloc_size;
+ num_bytes -= cur_alloc_size;
+ alloc_hint = ins.objectid + ins.offset;
+ start += cur_alloc_size;
+ }
+out:
+ ret = 0;
+ btrfs_end_transaction(trans, root);
+
+ return ret;
+}
+
+/*
+ * work queue call back to started compression on a file and pages
+ */
+static noinline void async_cow_start(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ int num_added = 0;
+ async_cow = container_of(work, struct async_cow, work);
+
+ compress_file_range(async_cow->inode, async_cow->locked_page,
+ async_cow->start, async_cow->end, async_cow,
+ &num_added);
+ if (num_added == 0)
+ async_cow->inode = NULL;
+}
+
+/*
+ * work queue call back to submit previously compressed pages
+ */
+static noinline void async_cow_submit(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ struct btrfs_root *root;
+ unsigned long nr_pages;
+
+ async_cow = container_of(work, struct async_cow, work);
+
+ root = async_cow->root;
+ nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+
+ atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
+
+ if (atomic_read(&root->fs_info->async_delalloc_pages) <
+ 5 * 1042 * 1024 &&
+ waitqueue_active(&root->fs_info->async_submit_wait))
+ wake_up(&root->fs_info->async_submit_wait);
+
+ if (async_cow->inode)
+ submit_compressed_extents(async_cow->inode, async_cow);
+}
+
+static noinline void async_cow_free(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ async_cow = container_of(work, struct async_cow, work);
+ kfree(async_cow);
+}
+
+static int cow_file_range_async(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written)
+{
+ struct async_cow *async_cow;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long nr_pages;
+ u64 cur_end;
+ int limit = 10 * 1024 * 1042;
+
+ if (!btrfs_test_opt(root, COMPRESS)) {
+ return cow_file_range(inode, locked_page, start, end,
+ page_started, nr_written, 1);
+ }
+
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED |
+ EXTENT_DELALLOC, 1, 0, GFP_NOFS);
+ while (start < end) {
+ async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
+ async_cow->inode = inode;
+ async_cow->root = root;
+ async_cow->locked_page = locked_page;
+ async_cow->start = start;
+
+ if (btrfs_test_flag(inode, NOCOMPRESS))
+ cur_end = end;
+ else
+ cur_end = min(end, start + 512 * 1024 - 1);
+
+ async_cow->end = cur_end;
+ INIT_LIST_HEAD(&async_cow->extents);
+
+ async_cow->work.func = async_cow_start;
+ async_cow->work.ordered_func = async_cow_submit;
+ async_cow->work.ordered_free = async_cow_free;
+ async_cow->work.flags = 0;
+
+ nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+ atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
+
+ btrfs_queue_worker(&root->fs_info->delalloc_workers,
+ &async_cow->work);
+
+ if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->async_delalloc_pages) <
+ limit));
+ }
+
+ while (atomic_read(&root->fs_info->async_submit_draining) &&
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->async_delalloc_pages) ==
+ 0));
+ }
+
+ *nr_written += nr_pages;
+ start = cur_end + 1;
+ }
+ *page_started = 1;
+ return 0;
+}
+
+static noinline int csum_exist_in_range(struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes)
+{
+ int ret;
+ struct btrfs_ordered_sum *sums;
+ LIST_HEAD(list);
+
+ ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
+ bytenr + num_bytes - 1, &list);
+ if (ret == 0 && list_empty(&list))
+ return 0;
+
+ while (!list_empty(&list)) {
+ sums = list_entry(list.next, struct btrfs_ordered_sum, list);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+ return 1;
+}
+
+/*
+ * when nowcow writeback call back. This checks for snapshots or COW copies
+ * of the extents that exist in the file, and COWs the file as required.
+ *
+ * If no cow copies or snapshots exist, we write directly to the existing
+ * blocks on disk
+ */
+static int run_delalloc_nocow(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started, int force,
+ unsigned long *nr_written)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct extent_buffer *leaf;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key found_key;
+ u64 cow_start;
+ u64 cur_offset;
+ u64 extent_end;
+ u64 disk_bytenr;
+ u64 num_bytes;
+ int extent_type;
+ int ret;
+ int type;
+ int nocow;
+ int check_prev = 1;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+
+ cow_start = (u64)-1;
+ cur_offset = start;
+ while (1) {
+ ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+ cur_offset, 0);
+ BUG_ON(ret < 0);
+ if (ret > 0 && path->slots[0] > 0 && check_prev) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key,
+ path->slots[0] - 1);
+ if (found_key.objectid == inode->i_ino &&
+ found_key.type == BTRFS_EXTENT_DATA_KEY)
+ path->slots[0]--;
+ }
+ check_prev = 0;
+next_slot:
+ leaf = path->nodes[0];
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ BUG_ON(1);
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ }
+
+ nocow = 0;
+ disk_bytenr = 0;
+ num_bytes = 0;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid > inode->i_ino ||
+ found_key.type > BTRFS_EXTENT_DATA_KEY ||
+ found_key.offset > end)
+ break;
+
+ if (found_key.offset > cur_offset) {
+ extent_end = found_key.offset;
+ goto out_check;
+ }
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+
+ if (extent_type == BTRFS_FILE_EXTENT_REG ||
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ extent_end = found_key.offset +
+ btrfs_file_extent_num_bytes(leaf, fi);
+ if (extent_end <= start) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+ if (disk_bytenr == 0)
+ goto out_check;
+ if (btrfs_file_extent_compression(leaf, fi) ||
+ btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ goto out_check;
+ if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
+ goto out_check;
+ if (btrfs_extent_readonly(root, disk_bytenr))
+ goto out_check;
+ if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
+ disk_bytenr))
+ goto out_check;
+ disk_bytenr += btrfs_file_extent_offset(leaf, fi);
+ disk_bytenr += cur_offset - found_key.offset;
+ num_bytes = min(end + 1, extent_end) - cur_offset;
+ /*
+ * force cow if csum exists in the range.
+ * this ensure that csum for a given extent are
+ * either valid or do not exist.
+ */
+ if (csum_exist_in_range(root, disk_bytenr, num_bytes))
+ goto out_check;
+ nocow = 1;
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ extent_end = found_key.offset +
+ btrfs_file_extent_inline_len(leaf, fi);
+ extent_end = ALIGN(extent_end, root->sectorsize);
+ } else {
+ BUG_ON(1);
+ }
+out_check:
+ if (extent_end <= start) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+ if (!nocow) {
+ if (cow_start == (u64)-1)
+ cow_start = cur_offset;
+ cur_offset = extent_end;
+ if (cur_offset > end)
+ break;
+ path->slots[0]++;
+ goto next_slot;
+ }
+
+ btrfs_release_path(root, path);
+ if (cow_start != (u64)-1) {
+ ret = cow_file_range(inode, locked_page, cow_start,
+ found_key.offset - 1, page_started,
+ nr_written, 1);
+ BUG_ON(ret);
+ cow_start = (u64)-1;
+ }
+
+ if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ struct extent_map *em;
+ struct extent_map_tree *em_tree;
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = cur_offset;
+ em->orig_start = em->start;
+ em->len = num_bytes;
+ em->block_len = num_bytes;
+ em->block_start = disk_bytenr;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ while (1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, em->start,
+ em->start + em->len - 1, 0);
+ }
+ type = BTRFS_ORDERED_PREALLOC;
+ } else {
+ type = BTRFS_ORDERED_NOCOW;
+ }
+
+ ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
+ num_bytes, num_bytes, type);
+ BUG_ON(ret);
+
+ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
+ cur_offset, cur_offset + num_bytes - 1,
+ locked_page, 1, 1, 1, 0, 0, 0);
+ cur_offset = extent_end;
+ if (cur_offset > end)
+ break;
+ }
+ btrfs_release_path(root, path);
+
+ if (cur_offset <= end && cow_start == (u64)-1)
+ cow_start = cur_offset;
+ if (cow_start != (u64)-1) {
+ ret = cow_file_range(inode, locked_page, cow_start, end,
+ page_started, nr_written, 1);
+ BUG_ON(ret);
+ }
+
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ btrfs_free_path(path);
+ return 0;
+}
+
+/*
+ * extent_io.c call back to do delayed allocation processing
+ */
+static int run_delalloc_range(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written)
+{
+ int ret;
+
+ if (btrfs_test_flag(inode, NODATACOW))
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 1, nr_written);
+ else if (btrfs_test_flag(inode, PREALLOC))
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 0, nr_written);
+ else
+ ret = cow_file_range_async(inode, locked_page, start, end,
+ page_started, nr_written);
+
+ return ret;
+}
+
+/*
+ * extent_io.c set_bit_hook, used to track delayed allocation
+ * bytes in this file, and to maintain the list of inodes that
+ * have pending delalloc work to be done.
+ */
+static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
+ unsigned long old, unsigned long bits)
+{
+ /*
+ * set_bit and clear bit hooks normally require _irqsave/restore
+ * but in this case, we are only testeing for the DELALLOC
+ * bit, which is only set or cleared with irqs on
+ */
+ if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ spin_lock(&root->fs_info->delalloc_lock);
+ BTRFS_I(inode)->delalloc_bytes += end - start + 1;
+ root->fs_info->delalloc_bytes += end - start + 1;
+ if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+ list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
+ &root->fs_info->delalloc_inodes);
+ }
+ spin_unlock(&root->fs_info->delalloc_lock);
+ }
+ return 0;
+}
+
+/*
+ * extent_io.c clear_bit_hook, see set_bit_hook for why
+ */
+static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
+ unsigned long old, unsigned long bits)
+{
+ /*
+ * set_bit and clear bit hooks normally require _irqsave/restore
+ * but in this case, we are only testeing for the DELALLOC
+ * bit, which is only set or cleared with irqs on
+ */
+ if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ spin_lock(&root->fs_info->delalloc_lock);
+ if (end - start + 1 > root->fs_info->delalloc_bytes) {
+ printk(KERN_INFO "btrfs warning: delalloc account "
+ "%llu %llu\n",
+ (unsigned long long)end - start + 1,
+ (unsigned long long)
+ root->fs_info->delalloc_bytes);
+ root->fs_info->delalloc_bytes = 0;
+ BTRFS_I(inode)->delalloc_bytes = 0;
+ } else {
+ root->fs_info->delalloc_bytes -= end - start + 1;
+ BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
+ }
+ if (BTRFS_I(inode)->delalloc_bytes == 0 &&
+ !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+ list_del_init(&BTRFS_I(inode)->delalloc_inodes);
+ }
+ spin_unlock(&root->fs_info->delalloc_lock);
+ }
+ return 0;
+}
+
+/*
+ * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
+ * we don't create bios that span stripes or chunks
+ */
+int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
+ size_t size, struct bio *bio,
+ unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+ struct btrfs_mapping_tree *map_tree;
+ u64 logical = (u64)bio->bi_sector << 9;
+ u64 length = 0;
+ u64 map_length;
+ int ret;
+
+ if (bio_flags & EXTENT_BIO_COMPRESSED)
+ return 0;
+
+ length = bio->bi_size;
+ map_tree = &root->fs_info->mapping_tree;
+ map_length = length;
+ ret = btrfs_map_block(map_tree, READ, logical,
+ &map_length, NULL, 0);
+
+ if (map_length < length + size)
+ return 1;
+ return 0;
+}
+
+/*
+ * in order to insert checksums into the metadata in large chunks,
+ * we wait until bio submission time. All the pages in the bio are
+ * checksummed and sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the cums attached on the ordered extent record
+ * are inserted into the btree
+ */
+static int __btrfs_submit_bio_start(struct inode *inode, int rw,
+ struct bio *bio, int mirror_num,
+ unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
+ BUG_ON(ret);
+ return 0;
+}
+
+/*
+ * in order to insert checksums into the metadata in large chunks,
+ * we wait until bio submission time. All the pages in the bio are
+ * checksummed and sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the cums attached on the ordered extent record
+ * are inserted into the btree
+ */
+static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ return btrfs_map_bio(root, rw, bio, mirror_num, 1);
+}
+
+/*
+ * extent_io.c submission hook. This does the right thing for csum calculation
+ * on write, or reading the csums from the tree before a read
+ */
+static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ int skip_sum;
+
+ skip_sum = btrfs_test_flag(inode, NODATASUM);
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+ BUG_ON(ret);
+
+ if (!(rw & (1 << BIO_RW))) {
+ if (bio_flags & EXTENT_BIO_COMPRESSED) {
+ return btrfs_submit_compressed_read(inode, bio,
+ mirror_num, bio_flags);
+ } else if (!skip_sum)
+ btrfs_lookup_bio_sums(root, inode, bio, NULL);
+ goto mapit;
+ } else if (!skip_sum) {
+ /* csum items have already been cloned */
+ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
+ goto mapit;
+ /* we're doing a write, do the async checksumming */
+ return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
+ inode, rw, bio, mirror_num,
+ bio_flags, __btrfs_submit_bio_start,
+ __btrfs_submit_bio_done);
+ }
+
+mapit:
+ return btrfs_map_bio(root, rw, bio, mirror_num, 0);
+}
+
+/*
+ * given a list of ordered sums record them in the inode. This happens
+ * at IO completion time based on sums calculated at bio submission time.
+ */
+static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_offset,
+ struct list_head *list)
+{
+ struct list_head *cur;
+ struct btrfs_ordered_sum *sum;
+
+ btrfs_set_trans_block_group(trans, inode);
+ list_for_each(cur, list) {
+ sum = list_entry(cur, struct btrfs_ordered_sum, list);
+ btrfs_csum_file_blocks(trans,
+ BTRFS_I(inode)->root->fs_info->csum_root, sum);
+ }
+ return 0;
+}
+
+int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end)
+{
+ if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
+ WARN_ON(1);
+ return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
+ GFP_NOFS);
+}
+
+/* see btrfs_writepage_start_hook for details on why this is required */
+struct btrfs_writepage_fixup {
+ struct page *page;
+ struct btrfs_work work;
+};
+
+static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
+{
+ struct btrfs_writepage_fixup *fixup;
+ struct btrfs_ordered_extent *ordered;
+ struct page *page;
+ struct inode *inode;
+ u64 page_start;
+ u64 page_end;
+
+ fixup = container_of(work, struct btrfs_writepage_fixup, work);
+ page = fixup->page;
+again:
+ lock_page(page);
+ if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
+ ClearPageChecked(page);
+ goto out_page;
+ }
+
+ inode = page->mapping->host;
+ page_start = page_offset(page);
+ page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
+
+ lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
+
+ /* already ordered? We're done */
+ if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+ EXTENT_ORDERED, 0)) {
+ goto out;
+ }
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, page_start,
+ page_end, GFP_NOFS);
+ unlock_page(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ goto again;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ ClearPageChecked(page);
+out:
+ unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
+out_page:
+ unlock_page(page);
+ page_cache_release(page);
+}
+
+/*
+ * There are a few paths in the higher layers of the kernel that directly
+ * set the page dirty bit without asking the filesystem if it is a
+ * good idea. This causes problems because we want to make sure COW
+ * properly happens and the data=ordered rules are followed.
+ *
+ * In our case any range that doesn't have the ORDERED bit set
+ * hasn't been properly setup for IO. We kick off an async process
+ * to fix it up. The async helper will wait for ordered extents, set
+ * the delalloc bit and make it safe to write the page.
+ */
+static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
+{
+ struct inode *inode = page->mapping->host;
+ struct btrfs_writepage_fixup *fixup;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
+ EXTENT_ORDERED, 0);
+ if (ret)
+ return 0;
+
+ if (PageChecked(page))
+ return -EAGAIN;
+
+ fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
+ if (!fixup)
+ return -EAGAIN;
+
+ SetPageChecked(page);
+ page_cache_get(page);
+ fixup->work.func = btrfs_writepage_fixup_worker;
+ fixup->page = page;
+ btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
+ return -EAGAIN;
+}
+
+static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_pos,
+ u64 disk_bytenr, u64 disk_num_bytes,
+ u64 num_bytes, u64 ram_bytes,
+ u8 compression, u8 encryption,
+ u16 other_encoding, int extent_type)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key ins;
+ u64 hint;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ ret = btrfs_drop_extents(trans, root, inode, file_pos,
+ file_pos + num_bytes, file_pos, &hint);
+ BUG_ON(ret);
+
+ ins.objectid = inode->i_ino;
+ ins.offset = file_pos;
+ ins.type = BTRFS_EXTENT_DATA_KEY;
+ ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
+ BUG_ON(ret);
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+ btrfs_set_file_extent_type(leaf, fi, extent_type);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
+ btrfs_set_file_extent_offset(leaf, fi, 0);
+ btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
+ btrfs_set_file_extent_compression(leaf, fi, compression);
+ btrfs_set_file_extent_encryption(leaf, fi, encryption);
+ btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
+ btrfs_mark_buffer_dirty(leaf);
+
+ inode_add_bytes(inode, num_bytes);
+ btrfs_drop_extent_cache(inode, file_pos, file_pos + num_bytes - 1, 0);
+
+ ins.objectid = disk_bytenr;
+ ins.offset = disk_num_bytes;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
+ root->root_key.objectid,
+ trans->transid, inode->i_ino, &ins);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return 0;
+}
+
+/* as ordered data IO finishes, this gets called so we can finish
+ * an ordered extent if the range of bytes in the file it covers are
+ * fully written.
+ */
+static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_ordered_extent *ordered_extent;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ int compressed = 0;
+ int ret;
+
+ ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
+ if (!ret)
+ return 0;
+
+ trans = btrfs_join_transaction(root, 1);
+
+ ordered_extent = btrfs_lookup_ordered_extent(inode, start);
+ BUG_ON(!ordered_extent);
+ if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
+ goto nocow;
+
+ lock_extent(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ GFP_NOFS);
+
+ if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
+ compressed = 1;
+ if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
+ BUG_ON(compressed);
+ ret = btrfs_mark_extent_written(trans, root, inode,
+ ordered_extent->file_offset,
+ ordered_extent->file_offset +
+ ordered_extent->len);
+ BUG_ON(ret);
+ } else {
+ ret = insert_reserved_file_extent(trans, inode,
+ ordered_extent->file_offset,
+ ordered_extent->start,
+ ordered_extent->disk_len,
+ ordered_extent->len,
+ ordered_extent->len,
+ compressed, 0, 0,
+ BTRFS_FILE_EXTENT_REG);
+ BUG_ON(ret);
+ }
+ unlock_extent(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ GFP_NOFS);
+nocow:
+ add_pending_csums(trans, inode, ordered_extent->file_offset,
+ &ordered_extent->list);
+
+ mutex_lock(&BTRFS_I(inode)->extent_mutex);
+ btrfs_ordered_update_i_size(inode, ordered_extent);
+ btrfs_update_inode(trans, root, inode);
+ btrfs_remove_ordered_extent(inode, ordered_extent);
+ mutex_unlock(&BTRFS_I(inode)->extent_mutex);
+
+ /* once for us */
+ btrfs_put_ordered_extent(ordered_extent);
+ /* once for the tree */
+ btrfs_put_ordered_extent(ordered_extent);
+
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state, int uptodate)
+{
+ return btrfs_finish_ordered_io(page->mapping->host, start, end);
+}
+
+/*
+ * When IO fails, either with EIO or csum verification fails, we
+ * try other mirrors that might have a good copy of the data. This
+ * io_failure_record is used to record state as we go through all the
+ * mirrors. If another mirror has good data, the page is set up to date
+ * and things continue. If a good mirror can't be found, the original
+ * bio end_io callback is called to indicate things have failed.
+ */
+struct io_failure_record {
+ struct page *page;
+ u64 start;
+ u64 len;
+ u64 logical;
+ unsigned long bio_flags;
+ int last_mirror;
+};
+
+static int btrfs_io_failed_hook(struct bio *failed_bio,
+ struct page *page, u64 start, u64 end,
+ struct extent_state *state)
+{
+ struct io_failure_record *failrec = NULL;
+ u64 private;
+ struct extent_map *em;
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct bio *bio;
+ int num_copies;
+ int ret;
+ int rw;
+ u64 logical;
+
+ ret = get_state_private(failure_tree, start, &private);
+ if (ret) {
+ failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
+ if (!failrec)
+ return -ENOMEM;
+ failrec->start = start;
+ failrec->len = end - start + 1;
+ failrec->last_mirror = 0;
+ failrec->bio_flags = 0;
+
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, failrec->len);
+ if (em->start > start || em->start + em->len < start) {
+ free_extent_map(em);
+ em = NULL;
+ }
+ spin_unlock(&em_tree->lock);
+
+ if (!em || IS_ERR(em)) {
+ kfree(failrec);
+ return -EIO;
+ }
+ logical = start - em->start;
+ logical = em->block_start + logical;
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+ logical = em->block_start;
+ failrec->bio_flags = EXTENT_BIO_COMPRESSED;
+ }
+ failrec->logical = logical;
+ free_extent_map(em);
+ set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
+ EXTENT_DIRTY, GFP_NOFS);
+ set_state_private(failure_tree, start,
+ (u64)(unsigned long)failrec);
+ } else {
+ failrec = (struct io_failure_record *)(unsigned long)private;
+ }
+ num_copies = btrfs_num_copies(
+ &BTRFS_I(inode)->root->fs_info->mapping_tree,
+ failrec->logical, failrec->len);
+ failrec->last_mirror++;
+ if (!state) {
+ spin_lock(&BTRFS_I(inode)->io_tree.lock);
+ state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
+ failrec->start,
+ EXTENT_LOCKED);
+ if (state && state->start != failrec->start)
+ state = NULL;
+ spin_unlock(&BTRFS_I(inode)->io_tree.lock);
+ }
+ if (!state || failrec->last_mirror > num_copies) {
+ set_state_private(failure_tree, failrec->start, 0);
+ clear_extent_bits(failure_tree, failrec->start,
+ failrec->start + failrec->len - 1,
+ EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
+ kfree(failrec);
+ return -EIO;
+ }
+ bio = bio_alloc(GFP_NOFS, 1);
+ bio->bi_private = state;
+ bio->bi_end_io = failed_bio->bi_end_io;
+ bio->bi_sector = failrec->logical >> 9;
+ bio->bi_bdev = failed_bio->bi_bdev;
+ bio->bi_size = 0;
+
+ bio_add_page(bio, page, failrec->len, start - page_offset(page));
+ if (failed_bio->bi_rw & (1 << BIO_RW))
+ rw = WRITE;
+ else
+ rw = READ;
+
+ BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
+ failrec->last_mirror,
+ failrec->bio_flags);
+ return 0;
+}
+
+/*
+ * each time an IO finishes, we do a fast check in the IO failure tree
+ * to see if we need to process or clean up an io_failure_record
+ */
+static int btrfs_clean_io_failures(struct inode *inode, u64 start)
+{
+ u64 private;
+ u64 private_failure;
+ struct io_failure_record *failure;
+ int ret;
+
+ private = 0;
+ if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
+ (u64)-1, 1, EXTENT_DIRTY)) {
+ ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
+ start, &private_failure);
+ if (ret == 0) {
+ failure = (struct io_failure_record *)(unsigned long)
+ private_failure;
+ set_state_private(&BTRFS_I(inode)->io_failure_tree,
+ failure->start, 0);
+ clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
+ failure->start,
+ failure->start + failure->len - 1,
+ EXTENT_DIRTY | EXTENT_LOCKED,
+ GFP_NOFS);
+ kfree(failure);
+ }
+ }
+ return 0;
+}
+
+/*
+ * when reads are done, we need to check csums to verify the data is correct
+ * if there's a match, we allow the bio to finish. If not, we go through
+ * the io_failure_record routines to find good copies
+ */
+static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state)
+{
+ size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ char *kaddr;
+ u64 private = ~(u32)0;
+ int ret;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u32 csum = ~(u32)0;
+
+ if (PageChecked(page)) {
+ ClearPageChecked(page);
+ goto good;
+ }
+ if (btrfs_test_flag(inode, NODATASUM))
+ return 0;
+
+ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
+ test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1)) {
+ clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
+ GFP_NOFS);
+ return 0;
+ }
+
+ if (state && state->start == start) {
+ private = state->private;
+ ret = 0;
+ } else {
+ ret = get_state_private(io_tree, start, &private);
+ }
+ kaddr = kmap_atomic(page, KM_USER0);
+ if (ret)
+ goto zeroit;
+
+ csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
+ btrfs_csum_final(csum, (char *)&csum);
+ if (csum != private)
+ goto zeroit;
+
+ kunmap_atomic(kaddr, KM_USER0);
+good:
+ /* if the io failure tree for this inode is non-empty,
+ * check to see if we've recovered from a failed IO
+ */
+ btrfs_clean_io_failures(inode, start);
+ return 0;
+
+zeroit:
+ printk(KERN_INFO "btrfs csum failed ino %lu off %llu csum %u "
+ "private %llu\n", page->mapping->host->i_ino,
+ (unsigned long long)start, csum,
+ (unsigned long long)private);
+ memset(kaddr + offset, 1, end - start + 1);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ if (private == 0)
+ return 0;
+ return -EIO;
+}
+
+/*
+ * This creates an orphan entry for the given inode in case something goes
+ * wrong in the middle of an unlink/truncate.
+ */
+int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ spin_lock(&root->list_lock);
+
+ /* already on the orphan list, we're good */
+ if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
+ spin_unlock(&root->list_lock);
+ return 0;
+ }
+
+ list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+
+ spin_unlock(&root->list_lock);
+
+ /*
+ * insert an orphan item to track this unlinked/truncated file
+ */
+ ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
+
+ return ret;
+}
+
+/*
+ * We have done the truncate/delete so we can go ahead and remove the orphan
+ * item for this particular inode.
+ */
+int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ spin_lock(&root->list_lock);
+
+ if (list_empty(&BTRFS_I(inode)->i_orphan)) {
+ spin_unlock(&root->list_lock);
+ return 0;
+ }
+
+ list_del_init(&BTRFS_I(inode)->i_orphan);
+ if (!trans) {
+ spin_unlock(&root->list_lock);
+ return 0;
+ }
+
+ spin_unlock(&root->list_lock);
+
+ ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
+
+ return ret;
+}
+
+/*
+ * this cleans up any orphans that may be left on the list from the last use
+ * of this root.
+ */
+void btrfs_orphan_cleanup(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ struct btrfs_key key, found_key;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode;
+ int ret = 0, nr_unlink = 0, nr_truncate = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+ path->reada = -1;
+
+ key.objectid = BTRFS_ORPHAN_OBJECTID;
+ btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
+ key.offset = (u64)-1;
+
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ printk(KERN_ERR "Error searching slot for orphan: %d"
+ "\n", ret);
+ break;
+ }
+
+ /*
+ * if ret == 0 means we found what we were searching for, which
+ * is weird, but possible, so only screw with path if we didnt
+ * find the key and see if we have stuff that matches
+ */
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ /* pull out the item */
+ leaf = path->nodes[0];
+ item = btrfs_item_nr(leaf, path->slots[0]);
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ /* make sure the item matches what we want */
+ if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
+ break;
+ if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ /* release the path since we're done with it */
+ btrfs_release_path(root, path);
+
+ /*
+ * this is where we are basically btrfs_lookup, without the
+ * crossing root thing. we store the inode number in the
+ * offset of the orphan item.
+ */
+ inode = btrfs_iget_locked(root->fs_info->sb,
+ found_key.offset, root);
+ if (!inode)
+ break;
+
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+
+ /* have to set the location manually */
+ BTRFS_I(inode)->location.objectid = inode->i_ino;
+ BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ }
+
+ /*
+ * add this inode to the orphan list so btrfs_orphan_del does
+ * the proper thing when we hit it
+ */
+ spin_lock(&root->list_lock);
+ list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+ spin_unlock(&root->list_lock);
+
+ /*
+ * if this is a bad inode, means we actually succeeded in
+ * removing the inode, but not the orphan record, which means
+ * we need to manually delete the orphan since iput will just
+ * do a destroy_inode
+ */
+ if (is_bad_inode(inode)) {
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_orphan_del(trans, inode);
+ btrfs_end_transaction(trans, root);
+ iput(inode);
+ continue;
+ }
+
+ /* if we have links, this was a truncate, lets do that */
+ if (inode->i_nlink) {
+ nr_truncate++;
+ btrfs_truncate(inode);
+ } else {
+ nr_unlink++;
+ }
+
+ /* this will do delete_inode and everything for us */
+ iput(inode);
+ }
+
+ if (nr_unlink)
+ printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
+ if (nr_truncate)
+ printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
+
+ btrfs_free_path(path);
+}
+
+/*
+ * read an inode from the btree into the in-memory inode
+ */
+void btrfs_read_locked_inode(struct inode *inode)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_timespec *tspec;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key location;
+ u64 alloc_group_block;
+ u32 rdev;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
+
+ ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
+ if (ret)
+ goto make_bad;
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+
+ inode->i_mode = btrfs_inode_mode(leaf, inode_item);
+ inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
+ inode->i_uid = btrfs_inode_uid(leaf, inode_item);
+ inode->i_gid = btrfs_inode_gid(leaf, inode_item);
+ btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
+
+ tspec = btrfs_inode_atime(inode_item);
+ inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
+ inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
+
+ tspec = btrfs_inode_mtime(inode_item);
+ inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
+ inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
+
+ tspec = btrfs_inode_ctime(inode_item);
+ inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
+ inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
+
+ inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
+ BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
+ BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
+ inode->i_generation = BTRFS_I(inode)->generation;
+ inode->i_rdev = 0;
+ rdev = btrfs_inode_rdev(leaf, inode_item);
+
+ BTRFS_I(inode)->index_cnt = (u64)-1;
+ BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
+
+ alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
+ BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0,
+ alloc_group_block, 0);
+ btrfs_free_path(path);
+ inode_item = NULL;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ break;
+ case S_IFDIR:
+ inode->i_fop = &btrfs_dir_file_operations;
+ if (root == root->fs_info->tree_root)
+ inode->i_op = &btrfs_dir_ro_inode_operations;
+ else
+ inode->i_op = &btrfs_dir_inode_operations;
+ break;
+ case S_IFLNK:
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ break;
+ default:
+ init_special_inode(inode, inode->i_mode, rdev);
+ break;
+ }
+ return;
+
+make_bad:
+ btrfs_free_path(path);
+ make_bad_inode(inode);
+}
+
+/*
+ * given a leaf and an inode, copy the inode fields into the leaf
+ */
+static void fill_inode_item(struct btrfs_trans_handle *trans,
+ struct extent_buffer *leaf,
+ struct btrfs_inode_item *item,
+ struct inode *inode)
+{
+ btrfs_set_inode_uid(leaf, item, inode->i_uid);
+ btrfs_set_inode_gid(leaf, item, inode->i_gid);
+ btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
+ btrfs_set_inode_mode(leaf, item, inode->i_mode);
+ btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
+
+ btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
+ inode->i_atime.tv_sec);
+ btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
+ inode->i_atime.tv_nsec);
+
+ btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
+ inode->i_mtime.tv_sec);
+ btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
+ inode->i_mtime.tv_nsec);
+
+ btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
+ inode->i_ctime.tv_sec);
+ btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
+ inode->i_ctime.tv_nsec);
+
+ btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
+ btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
+ btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
+ btrfs_set_inode_transid(leaf, item, trans->transid);
+ btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
+ btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
+ btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group);
+}
+
+/*
+ * copy everything in the in-memory inode into the btree.
+ */
+noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode)
+{
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_lookup_inode(trans, root, path,
+ &BTRFS_I(inode)->location, 1);
+ if (ret) {
+ if (ret > 0)
+ ret = -ENOENT;
+ goto failed;
+ }
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+
+ fill_inode_item(trans, leaf, inode_item, inode);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_set_inode_last_trans(trans, inode);
+ ret = 0;
+failed:
+ btrfs_free_path(path);
+ return ret;
+}
+
+
+/*
+ * unlink helper that gets used here in inode.c and in the tree logging
+ * recovery code. It remove a link in a directory with a given name, and
+ * also drops the back refs in the inode to the directory
+ */
+int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, struct inode *inode,
+ const char *name, int name_len)
+{
+ struct btrfs_path *path;
+ int ret = 0;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ u64 index;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+ name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ leaf = path->nodes[0];
+ btrfs_dir_item_key_to_cpu(leaf, di, &key);
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ if (ret)
+ goto err;
+ btrfs_release_path(root, path);
+
+ ret = btrfs_del_inode_ref(trans, root, name, name_len,
+ inode->i_ino,
+ dir->i_ino, &index);
+ if (ret) {
+ printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
+ "inode %lu parent %lu\n", name_len, name,
+ inode->i_ino, dir->i_ino);
+ goto err;
+ }
+
+ di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
+ index, name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ btrfs_release_path(root, path);
+
+ ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
+ inode, dir->i_ino);
+ BUG_ON(ret != 0 && ret != -ENOENT);
+ if (ret != -ENOENT)
+ BTRFS_I(dir)->log_dirty_trans = trans->transid;
+
+ ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
+ dir, index);
+ BUG_ON(ret);
+err:
+ btrfs_free_path(path);
+ if (ret)
+ goto out;
+
+ btrfs_i_size_write(dir, dir->i_size - name_len * 2);
+ inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+ btrfs_update_inode(trans, root, dir);
+ btrfs_drop_nlink(inode);
+ ret = btrfs_update_inode(trans, root, inode);
+ dir->i_sb->s_dirt = 1;
+out:
+ return ret;
+}
+
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct btrfs_root *root;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode = dentry->d_inode;
+ int ret;
+ unsigned long nr = 0;
+
+ root = BTRFS_I(dir)->root;
+
+ ret = btrfs_check_free_space(root, 1, 1);
+ if (ret)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, dir);
+ ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
+ dentry->d_name.name, dentry->d_name.len);
+
+ if (inode->i_nlink == 0)
+ ret = btrfs_orphan_add(trans, inode);
+
+ nr = trans->blocks_used;
+
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ btrfs_btree_balance_dirty(root, nr);
+ return ret;
+}
+
+static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ int err = 0;
+ int ret;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr = 0;
+
+ /*
+ * the FIRST_FREE_OBJECTID check makes sure we don't try to rmdir
+ * the root of a subvolume or snapshot
+ */
+ if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
+ inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
+ return -ENOTEMPTY;
+ }
+
+ ret = btrfs_check_free_space(root, 1, 1);
+ if (ret)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_orphan_add(trans, inode);
+ if (err)
+ goto fail_trans;
+
+ /* now the directory is empty */
+ err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
+ dentry->d_name.name, dentry->d_name.len);
+ if (!err)
+ btrfs_i_size_write(inode, 0);
+
+fail_trans:
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction_throttle(trans, root);
+fail:
+ btrfs_btree_balance_dirty(root, nr);
+
+ if (ret && !err)
+ err = ret;
+ return err;
+}
+
+#if 0
+/*
+ * when truncating bytes in a file, it is possible to avoid reading
+ * the leaves that contain only checksum items. This can be the
+ * majority of the IO required to delete a large file, but it must
+ * be done carefully.
+ *
+ * The keys in the level just above the leaves are checked to make sure
+ * the lowest key in a given leaf is a csum key, and starts at an offset
+ * after the new size.
+ *
+ * Then the key for the next leaf is checked to make sure it also has
+ * a checksum item for the same file. If it does, we know our target leaf
+ * contains only checksum items, and it can be safely freed without reading
+ * it.
+ *
+ * This is just an optimization targeted at large files. It may do
+ * nothing. It will return 0 unless things went badly.
+ */
+static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct inode *inode, u64 new_size)
+{
+ struct btrfs_key key;
+ int ret;
+ int nritems;
+ struct btrfs_key found_key;
+ struct btrfs_key other_key;
+ struct btrfs_leaf_ref *ref;
+ u64 leaf_gen;
+ u64 leaf_start;
+
+ path->lowest_level = 1;
+ key.objectid = inode->i_ino;
+ key.type = BTRFS_CSUM_ITEM_KEY;
+ key.offset = new_size;
+again:
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+
+ if (path->nodes[1] == NULL) {
+ ret = 0;
+ goto out;
+ }
+ ret = 0;
+ btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]);
+ nritems = btrfs_header_nritems(path->nodes[1]);
+
+ if (!nritems)
+ goto out;
+
+ if (path->slots[1] >= nritems)
+ goto next_node;
+
+ /* did we find a key greater than anything we want to delete? */
+ if (found_key.objectid > inode->i_ino ||
+ (found_key.objectid == inode->i_ino && found_key.type > key.type))
+ goto out;
+
+ /* we check the next key in the node to make sure the leave contains
+ * only checksum items. This comparison doesn't work if our
+ * leaf is the last one in the node
+ */
+ if (path->slots[1] + 1 >= nritems) {
+next_node:
+ /* search forward from the last key in the node, this
+ * will bring us into the next node in the tree
+ */
+ btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1);
+
+ /* unlikely, but we inc below, so check to be safe */
+ if (found_key.offset == (u64)-1)
+ goto out;
+
+ /* search_forward needs a path with locks held, do the
+ * search again for the original key. It is possible
+ * this will race with a balance and return a path that
+ * we could modify, but this drop is just an optimization
+ * and is allowed to miss some leaves.
+ */
+ btrfs_release_path(root, path);
+ found_key.offset++;
+
+ /* setup a max key for search_forward */
+ other_key.offset = (u64)-1;
+ other_key.type = key.type;
+ other_key.objectid = key.objectid;
+
+ path->keep_locks = 1;
+ ret = btrfs_search_forward(root, &found_key, &other_key,
+ path, 0, 0);
+ path->keep_locks = 0;
+ if (ret || found_key.objectid != key.objectid ||
+ found_key.type != key.type) {
+ ret = 0;
+ goto out;
+ }
+
+ key.offset = found_key.offset;
+ btrfs_release_path(root, path);
+ cond_resched();
+ goto again;
+ }
+
+ /* we know there's one more slot after us in the tree,
+ * read that key so we can verify it is also a checksum item
+ */
+ btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1);
+
+ if (found_key.objectid < inode->i_ino)
+ goto next_key;
+
+ if (found_key.type != key.type || found_key.offset < new_size)
+ goto next_key;
+
+ /*
+ * if the key for the next leaf isn't a csum key from this objectid,
+ * we can't be sure there aren't good items inside this leaf.
+ * Bail out
+ */
+ if (other_key.objectid != inode->i_ino || other_key.type != key.type)
+ goto out;
+
+ leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
+ leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
+ /*
+ * it is safe to delete this leaf, it contains only
+ * csum items from this inode at an offset >= new_size
+ */
+ ret = btrfs_del_leaf(trans, root, path, leaf_start);
+ BUG_ON(ret);
+
+ if (root->ref_cows && leaf_gen < trans->transid) {
+ ref = btrfs_alloc_leaf_ref(root, 0);
+ if (ref) {
+ ref->root_gen = root->root_key.offset;
+ ref->bytenr = leaf_start;
+ ref->owner = 0;
+ ref->generation = leaf_gen;
+ ref->nritems = 0;
+
+ ret = btrfs_add_leaf_ref(root, ref, 0);
+ WARN_ON(ret);
+ btrfs_free_leaf_ref(root, ref);
+ } else {
+ WARN_ON(1);
+ }
+ }
+next_key:
+ btrfs_release_path(root, path);
+
+ if (other_key.objectid == inode->i_ino &&
+ other_key.type == key.type && other_key.offset > key.offset) {
+ key.offset = other_key.offset;
+ cond_resched();
+ goto again;
+ }
+ ret = 0;
+out:
+ /* fixup any changes we've made to the path */
+ path->lowest_level = 0;
+ path->keep_locks = 0;
+ btrfs_release_path(root, path);
+ return ret;
+}
+
+#endif
+
+/*
+ * this can truncate away extent items, csum items and directory items.
+ * It starts at a high offset and removes keys until it can't find
+ * any higher than new_size
+ *
+ * csum items that cross the new i_size are truncated to the new size
+ * as well.
+ *
+ * min_type is the minimum key type to truncate down to. If set to 0, this
+ * will kill all the items on this inode, including the INODE_ITEM_KEY.
+ */
+noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode,
+ u64 new_size, u32 min_type)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u32 found_type;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ u64 extent_start = 0;
+ u64 extent_num_bytes = 0;
+ u64 item_end = 0;
+ u64 root_gen = 0;
+ u64 root_owner = 0;
+ int found_extent;
+ int del_item;
+ int pending_del_nr = 0;
+ int pending_del_slot = 0;
+ int extent_type = -1;
+ int encoding;
+ u64 mask = root->sectorsize - 1;
+
+ if (root->ref_cows)
+ btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
+ path = btrfs_alloc_path();
+ path->reada = -1;
+ BUG_ON(!path);
+
+ /* FIXME, add redo link to tree so we don't leak on crash */
+ key.objectid = inode->i_ino;
+ key.offset = (u64)-1;
+ key.type = (u8)-1;
+
+ btrfs_init_path(path);
+
+search_again:
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto error;
+
+ if (ret > 0) {
+ /* there are no items in the tree for us to truncate, we're
+ * done
+ */
+ if (path->slots[0] == 0) {
+ ret = 0;
+ goto error;
+ }
+ path->slots[0]--;
+ }
+
+ while (1) {
+ fi = NULL;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ found_type = btrfs_key_type(&found_key);
+ encoding = 0;
+
+ if (found_key.objectid != inode->i_ino)
+ break;
+
+ if (found_type < min_type)
+ break;
+
+ item_end = found_key.offset;
+ if (found_type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+ encoding = btrfs_file_extent_compression(leaf, fi);
+ encoding |= btrfs_file_extent_encryption(leaf, fi);
+ encoding |= btrfs_file_extent_other_encoding(leaf, fi);
+
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ item_end +=
+ btrfs_file_extent_num_bytes(leaf, fi);
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ item_end += btrfs_file_extent_inline_len(leaf,
+ fi);
+ }
+ item_end--;
+ }
+ if (item_end < new_size) {
+ if (found_type == BTRFS_DIR_ITEM_KEY)
+ found_type = BTRFS_INODE_ITEM_KEY;
+ else if (found_type == BTRFS_EXTENT_ITEM_KEY)
+ found_type = BTRFS_EXTENT_DATA_KEY;
+ else if (found_type == BTRFS_EXTENT_DATA_KEY)
+ found_type = BTRFS_XATTR_ITEM_KEY;
+ else if (found_type == BTRFS_XATTR_ITEM_KEY)
+ found_type = BTRFS_INODE_REF_KEY;
+ else if (found_type)
+ found_type--;
+ else
+ break;
+ btrfs_set_key_type(&key, found_type);
+ goto next;
+ }
+ if (found_key.offset >= new_size)
+ del_item = 1;
+ else
+ del_item = 0;
+ found_extent = 0;
+
+ /* FIXME, shrink the extent if the ref count is only 1 */
+ if (found_type != BTRFS_EXTENT_DATA_KEY)
+ goto delete;
+
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ u64 num_dec;
+ extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
+ if (!del_item && !encoding) {
+ u64 orig_num_bytes =
+ btrfs_file_extent_num_bytes(leaf, fi);
+ extent_num_bytes = new_size -
+ found_key.offset + root->sectorsize - 1;
+ extent_num_bytes = extent_num_bytes &
+ ~((u64)root->sectorsize - 1);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_num_bytes);
+ num_dec = (orig_num_bytes -
+ extent_num_bytes);
+ if (root->ref_cows && extent_start != 0)
+ inode_sub_bytes(inode, num_dec);
+ btrfs_mark_buffer_dirty(leaf);
+ } else {
+ extent_num_bytes =
+ btrfs_file_extent_disk_num_bytes(leaf,
+ fi);
+ /* FIXME blocksize != 4096 */
+ num_dec = btrfs_file_extent_num_bytes(leaf, fi);
+ if (extent_start != 0) {
+ found_extent = 1;
+ if (root->ref_cows)
+ inode_sub_bytes(inode, num_dec);
+ }
+ root_gen = btrfs_header_generation(leaf);
+ root_owner = btrfs_header_owner(leaf);
+ }
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ /*
+ * we can't truncate inline items that have had
+ * special encodings
+ */
+ if (!del_item &&
+ btrfs_file_extent_compression(leaf, fi) == 0 &&
+ btrfs_file_extent_encryption(leaf, fi) == 0 &&
+ btrfs_file_extent_other_encoding(leaf, fi) == 0) {
+ u32 size = new_size - found_key.offset;
+
+ if (root->ref_cows) {
+ inode_sub_bytes(inode, item_end + 1 -
+ new_size);
+ }
+ size =
+ btrfs_file_extent_calc_inline_size(size);
+ ret = btrfs_truncate_item(trans, root, path,
+ size, 1);
+ BUG_ON(ret);
+ } else if (root->ref_cows) {
+ inode_sub_bytes(inode, item_end + 1 -
+ found_key.offset);
+ }
+ }
+delete:
+ if (del_item) {
+ if (!pending_del_nr) {
+ /* no pending yet, add ourselves */
+ pending_del_slot = path->slots[0];
+ pending_del_nr = 1;
+ } else if (pending_del_nr &&
+ path->slots[0] + 1 == pending_del_slot) {
+ /* hop on the pending chunk */
+ pending_del_nr++;
+ pending_del_slot = path->slots[0];
+ } else {
+ BUG();
+ }
+ } else {
+ break;
+ }
+ if (found_extent) {
+ ret = btrfs_free_extent(trans, root, extent_start,
+ extent_num_bytes,
+ leaf->start, root_owner,
+ root_gen, inode->i_ino, 0);
+ BUG_ON(ret);
+ }
+next:
+ if (path->slots[0] == 0) {
+ if (pending_del_nr)
+ goto del_pending;
+ btrfs_release_path(root, path);
+ goto search_again;
+ }
+
+ path->slots[0]--;
+ if (pending_del_nr &&
+ path->slots[0] + 1 != pending_del_slot) {
+ struct btrfs_key debug;
+del_pending:
+ btrfs_item_key_to_cpu(path->nodes[0], &debug,
+ pending_del_slot);
+ ret = btrfs_del_items(trans, root, path,
+ pending_del_slot,
+ pending_del_nr);
+ BUG_ON(ret);
+ pending_del_nr = 0;
+ btrfs_release_path(root, path);
+ goto search_again;
+ }
+ }
+ ret = 0;
+error:
+ if (pending_del_nr) {
+ ret = btrfs_del_items(trans, root, path, pending_del_slot,
+ pending_del_nr);
+ }
+ btrfs_free_path(path);
+ inode->i_sb->s_dirt = 1;
+ return ret;
+}
+
+/*
+ * taken from block_truncate_page, but does cow as it zeros out
+ * any bytes left in the last page in the file.
+ */
+static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
+{
+ struct inode *inode = mapping->host;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ char *kaddr;
+ u32 blocksize = root->sectorsize;
+ pgoff_t index = from >> PAGE_CACHE_SHIFT;
+ unsigned offset = from & (PAGE_CACHE_SIZE-1);
+ struct page *page;
+ int ret = 0;
+ u64 page_start;
+ u64 page_end;
+
+ if ((offset & (blocksize - 1)) == 0)
+ goto out;
+
+ ret = -ENOMEM;
+again:
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ goto out;
+
+ page_start = page_offset(page);
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ if (!PageUptodate(page)) {
+ ret = btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (page->mapping != mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto again;
+ }
+ if (!PageUptodate(page)) {
+ ret = -EIO;
+ goto out_unlock;
+ }
+ }
+ wait_on_page_writeback(page);
+
+ lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ set_page_extent_mapped(page);
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ ret = 0;
+ if (offset != PAGE_CACHE_SIZE) {
+ kaddr = kmap(page);
+ memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+ flush_dcache_page(page);
+ kunmap(page);
+ }
+ ClearPageChecked(page);
+ set_page_dirty(page);
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+out_unlock:
+ unlock_page(page);
+ page_cache_release(page);
+out:
+ return ret;
+}
+
+int btrfs_cont_expand(struct inode *inode, loff_t size)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct extent_map *em;
+ u64 mask = root->sectorsize - 1;
+ u64 hole_start = (inode->i_size + mask) & ~mask;
+ u64 block_end = (size + mask) & ~mask;
+ u64 last_byte;
+ u64 cur_offset;
+ u64 hole_size;
+ int err;
+
+ if (size <= hole_start)
+ return 0;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ return err;
+
+ btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+ btrfs_wait_ordered_range(inode, hole_start,
+ block_end - hole_start);
+ lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
+ ordered = btrfs_lookup_ordered_extent(inode, hole_start);
+ if (!ordered)
+ break;
+ unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
+ btrfs_put_ordered_extent(ordered);
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ cur_offset = hole_start;
+ while (1) {
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ block_end - cur_offset, 0);
+ BUG_ON(IS_ERR(em) || !em);
+ last_byte = min(extent_map_end(em), block_end);
+ last_byte = (last_byte + mask) & ~mask;
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ u64 hint_byte = 0;
+ hole_size = last_byte - cur_offset;
+ err = btrfs_drop_extents(trans, root, inode,
+ cur_offset,
+ cur_offset + hole_size,
+ cur_offset, &hint_byte);
+ if (err)
+ break;
+ err = btrfs_insert_file_extent(trans, root,
+ inode->i_ino, cur_offset, 0,
+ 0, hole_size, 0, hole_size,
+ 0, 0, 0);
+ btrfs_drop_extent_cache(inode, hole_start,
+ last_byte - 1, 0);
+ }
+ free_extent_map(em);
+ cur_offset = last_byte;
+ if (err || cur_offset >= block_end)
+ break;
+ }
+
+ btrfs_end_transaction(trans, root);
+ unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
+ return err;
+}
+
+static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ int err;
+
+ err = inode_change_ok(inode, attr);
+ if (err)
+ return err;
+
+ if (S_ISREG(inode->i_mode) &&
+ attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
+ err = btrfs_cont_expand(inode, attr->ia_size);
+ if (err)
+ return err;
+ }
+
+ err = inode_setattr(inode, attr);
+
+ if (!err && ((attr->ia_valid & ATTR_MODE)))
+ err = btrfs_acl_chmod(inode);
+ return err;
+}
+
+void btrfs_delete_inode(struct inode *inode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long nr;
+ int ret;
+
+ truncate_inode_pages(&inode->i_data, 0);
+ if (is_bad_inode(inode)) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete;
+ }
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+
+ btrfs_i_size_write(inode, 0);
+ trans = btrfs_join_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, inode);
+ ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0);
+ if (ret) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete_lock;
+ }
+
+ btrfs_orphan_del(trans, inode);
+
+ nr = trans->blocks_used;
+ clear_inode(inode);
+
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+ return;
+
+no_delete_lock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+no_delete:
+ clear_inode(inode);
+}
+
+/*
+ * this returns the key found in the dir entry in the location pointer.
+ * If no dir entries were found, location->objectid is 0.
+ */
+static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
+ struct btrfs_key *location)
+{
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int ret = 0;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
+ namelen, 0);
+ if (IS_ERR(di))
+ ret = PTR_ERR(di);
+
+ if (!di || IS_ERR(di))
+ goto out_err;
+
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
+out:
+ btrfs_free_path(path);
+ return ret;
+out_err:
+ location->objectid = 0;
+ goto out;
+}
+
+/*
+ * when we hit a tree root in a directory, the btrfs part of the inode
+ * needs to be changed to reflect the root directory of the tree root. This
+ * is kind of like crossing a mount point.
+ */
+static int fixup_tree_root_location(struct btrfs_root *root,
+ struct btrfs_key *location,
+ struct btrfs_root **sub_root,
+ struct dentry *dentry)
+{
+ struct btrfs_root_item *ri;
+
+ if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
+ return 0;
+ if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+ return 0;
+
+ *sub_root = btrfs_read_fs_root(root->fs_info, location,
+ dentry->d_name.name,
+ dentry->d_name.len);
+ if (IS_ERR(*sub_root))
+ return PTR_ERR(*sub_root);
+
+ ri = &(*sub_root)->root_item;
+ location->objectid = btrfs_root_dirid(ri);
+ btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+ location->offset = 0;
+
+ return 0;
+}
+
+static noinline void init_btrfs_i(struct inode *inode)
+{
+ struct btrfs_inode *bi = BTRFS_I(inode);
+
+ bi->i_acl = NULL;
+ bi->i_default_acl = NULL;
+
+ bi->generation = 0;
+ bi->sequence = 0;
+ bi->last_trans = 0;
+ bi->logged_trans = 0;
+ bi->delalloc_bytes = 0;
+ bi->disk_i_size = 0;
+ bi->flags = 0;
+ bi->index_cnt = (u64)-1;
+ bi->log_dirty_trans = 0;
+ extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
+ extent_io_tree_init(&BTRFS_I(inode)->io_tree,
+ inode->i_mapping, GFP_NOFS);
+ extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
+ inode->i_mapping, GFP_NOFS);
+ INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
+ btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
+ mutex_init(&BTRFS_I(inode)->extent_mutex);
+ mutex_init(&BTRFS_I(inode)->log_mutex);
+}
+
+static int btrfs_init_locked_inode(struct inode *inode, void *p)
+{
+ struct btrfs_iget_args *args = p;
+ inode->i_ino = args->ino;
+ init_btrfs_i(inode);
+ BTRFS_I(inode)->root = args->root;
+ return 0;
+}
+
+static int btrfs_find_actor(struct inode *inode, void *opaque)
+{
+ struct btrfs_iget_args *args = opaque;
+ return args->ino == inode->i_ino &&
+ args->root == BTRFS_I(inode)->root;
+}
+
+struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
+ struct btrfs_root *root, int wait)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ args.ino = objectid;
+ args.root = root;
+
+ if (wait) {
+ inode = ilookup5(s, objectid, btrfs_find_actor,
+ (void *)&args);
+ } else {
+ inode = ilookup5_nowait(s, objectid, btrfs_find_actor,
+ (void *)&args);
+ }
+ return inode;
+}
+
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+ struct btrfs_root *root)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ args.ino = objectid;
+ args.root = root;
+
+ inode = iget5_locked(s, objectid, btrfs_find_actor,
+ btrfs_init_locked_inode,
+ (void *)&args);
+ return inode;
+}
+
+/* Get an inode object given its location and corresponding root.
+ * Returns in *is_new if the inode was read from disk
+ */
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+ struct btrfs_root *root, int *is_new)
+{
+ struct inode *inode;
+
+ inode = btrfs_iget_locked(s, location->objectid, root);
+ if (!inode)
+ return ERR_PTR(-EACCES);
+
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+ memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ if (is_new)
+ *is_new = 1;
+ } else {
+ if (is_new)
+ *is_new = 0;
+ }
+
+ return inode;
+}
+
+struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode;
+ struct btrfs_inode *bi = BTRFS_I(dir);
+ struct btrfs_root *root = bi->root;
+ struct btrfs_root *sub_root = root;
+ struct btrfs_key location;
+ int ret, new;
+
+ if (dentry->d_name.len > BTRFS_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ ret = btrfs_inode_by_name(dir, dentry, &location);
+
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ inode = NULL;
+ if (location.objectid) {
+ ret = fixup_tree_root_location(root, &location, &sub_root,
+ dentry);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return ERR_PTR(-ENOENT);
+ inode = btrfs_iget(dir->i_sb, &location, sub_root, &new);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ }
+ return inode;
+}
+
+static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+
+ if (dentry->d_name.len > BTRFS_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ inode = btrfs_lookup_dentry(dir, dentry);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+
+ return d_splice_alias(inode, dentry);
+}
+
+static unsigned char btrfs_filetype_table[] = {
+ DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int btrfs_real_readdir(struct file *filp, void *dirent,
+ filldir_t filldir)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_item *item;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+ int ret;
+ u32 nritems;
+ struct extent_buffer *leaf;
+ int slot;
+ int advance;
+ unsigned char d_type;
+ int over = 0;
+ u32 di_cur;
+ u32 di_total;
+ u32 di_len;
+ int key_type = BTRFS_DIR_INDEX_KEY;
+ char tmp_name[32];
+ char *name_ptr;
+ int name_len;
+
+ /* FIXME, use a real flag for deciding about the key type */
+ if (root->fs_info->tree_root == root)
+ key_type = BTRFS_DIR_ITEM_KEY;
+
+ /* special case for "." */
+ if (filp->f_pos == 0) {
+ over = filldir(dirent, ".", 1,
+ 1, inode->i_ino,
+ DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 1;
+ }
+ /* special case for .., just use the back ref */
+ if (filp->f_pos == 1) {
+ u64 pino = parent_ino(filp->f_path.dentry);
+ over = filldir(dirent, "..", 2,
+ 2, pino, DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 2;
+ }
+ path = btrfs_alloc_path();
+ path->reada = 2;
+
+ btrfs_set_key_type(&key, key_type);
+ key.offset = filp->f_pos;
+ key.objectid = inode->i_ino;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ advance = 0;
+
+ while (1) {
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ if (advance || slot >= nritems) {
+ if (slot >= nritems - 1) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ } else {
+ slot++;
+ path->slots[0]++;
+ }
+ }
+
+ advance = 1;
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ if (found_key.objectid != key.objectid)
+ break;
+ if (btrfs_key_type(&found_key) != key_type)
+ break;
+ if (found_key.offset < filp->f_pos)
+ continue;
+
+ filp->f_pos = found_key.offset;
+
+ di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+ di_cur = 0;
+ di_total = btrfs_item_size(leaf, item);
+
+ while (di_cur < di_total) {
+ struct btrfs_key location;
+
+ name_len = btrfs_dir_name_len(leaf, di);
+ if (name_len <= sizeof(tmp_name)) {
+ name_ptr = tmp_name;
+ } else {
+ name_ptr = kmalloc(name_len, GFP_NOFS);
+ if (!name_ptr) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
+ read_extent_buffer(leaf, name_ptr,
+ (unsigned long)(di + 1), name_len);
+
+ d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
+ btrfs_dir_item_key_to_cpu(leaf, di, &location);
+
+ /* is this a reference to our own snapshot? If so
+ * skip it
+ */
+ if (location.type == BTRFS_ROOT_ITEM_KEY &&
+ location.objectid == root->root_key.objectid) {
+ over = 0;
+ goto skip;
+ }
+ over = filldir(dirent, name_ptr, name_len,
+ found_key.offset, location.objectid,
+ d_type);
+
+skip:
+ if (name_ptr != tmp_name)
+ kfree(name_ptr);
+
+ if (over)
+ goto nopos;
+ di_len = btrfs_dir_name_len(leaf, di) +
+ btrfs_dir_data_len(leaf, di) + sizeof(*di);
+ di_cur += di_len;
+ di = (struct btrfs_dir_item *)((char *)di + di_len);
+ }
+ }
+
+ /* Reached end of directory/root. Bump pos past the last item. */
+ if (key_type == BTRFS_DIR_INDEX_KEY)
+ filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
+ else
+ filp->f_pos++;
+nopos:
+ ret = 0;
+err:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_write_inode(struct inode *inode, int wait)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ if (root->fs_info->btree_inode == inode)
+ return 0;
+
+ if (wait) {
+ trans = btrfs_join_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ ret = btrfs_commit_transaction(trans, root);
+ }
+ return ret;
+}
+
+/*
+ * This is somewhat expensive, updating the tree every time the
+ * inode changes. But, it is most likely to find the inode in cache.
+ * FIXME, needs more benchmarking...there are no reasons other than performance
+ * to keep or drop this code.
+ */
+void btrfs_dirty_inode(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+
+ trans = btrfs_join_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ btrfs_update_inode(trans, root, inode);
+ btrfs_end_transaction(trans, root);
+}
+
+/*
+ * find the highest existing sequence number in a directory
+ * and then set the in-memory index_cnt variable to reflect
+ * free sequence numbers
+ */
+static int btrfs_set_inode_index_count(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key key, found_key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret;
+
+ key.objectid = inode->i_ino;
+ btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+ key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ /* FIXME: we should be able to handle this */
+ if (ret == 0)
+ goto out;
+ ret = 0;
+
+ /*
+ * MAGIC NUMBER EXPLANATION:
+ * since we search a directory based on f_pos we have to start at 2
+ * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
+ * else has to start at 2
+ */
+ if (path->slots[0] == 0) {
+ BTRFS_I(inode)->index_cnt = 2;
+ goto out;
+ }
+
+ path->slots[0]--;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid != inode->i_ino ||
+ btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
+ BTRFS_I(inode)->index_cnt = 2;
+ goto out;
+ }
+
+ BTRFS_I(inode)->index_cnt = found_key.offset + 1;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper to find a free sequence number in a given directory. This current
+ * code is very simple, later versions will do smarter things in the btree
+ */
+int btrfs_set_inode_index(struct inode *dir, u64 *index)
+{
+ int ret = 0;
+
+ if (BTRFS_I(dir)->index_cnt == (u64)-1) {
+ ret = btrfs_set_inode_index_count(dir);
+ if (ret)
+ return ret;
+ }
+
+ *index = BTRFS_I(dir)->index_cnt;
+ BTRFS_I(dir)->index_cnt++;
+
+ return ret;
+}
+
+static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir,
+ const char *name, int name_len,
+ u64 ref_objectid, u64 objectid,
+ u64 alloc_hint, int mode, u64 *index)
+{
+ struct inode *inode;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_key *location;
+ struct btrfs_path *path;
+ struct btrfs_inode_ref *ref;
+ struct btrfs_key key[2];
+ u32 sizes[2];
+ unsigned long ptr;
+ int ret;
+ int owner;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ inode = new_inode(root->fs_info->sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ if (dir) {
+ ret = btrfs_set_inode_index(dir, index);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+ /*
+ * index_cnt is ignored for everything but a dir,
+ * btrfs_get_inode_index_count has an explanation for the magic
+ * number
+ */
+ init_btrfs_i(inode);
+ BTRFS_I(inode)->index_cnt = 2;
+ BTRFS_I(inode)->root = root;
+ BTRFS_I(inode)->generation = trans->transid;
+
+ if (mode & S_IFDIR)
+ owner = 0;
+ else
+ owner = 1;
+ BTRFS_I(inode)->block_group =
+ btrfs_find_block_group(root, 0, alloc_hint, owner);
+ if ((mode & S_IFREG)) {
+ if (btrfs_test_opt(root, NODATASUM))
+ btrfs_set_flag(inode, NODATASUM);
+ if (btrfs_test_opt(root, NODATACOW))
+ btrfs_set_flag(inode, NODATACOW);
+ }
+
+ key[0].objectid = objectid;
+ btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
+ key[0].offset = 0;
+
+ key[1].objectid = objectid;
+ btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
+ key[1].offset = ref_objectid;
+
+ sizes[0] = sizeof(struct btrfs_inode_item);
+ sizes[1] = name_len + sizeof(*ref);
+
+ ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
+ if (ret != 0)
+ goto fail;
+
+ if (objectid > root->highest_inode)
+ root->highest_inode = objectid;
+
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
+ inode->i_mode = mode;
+ inode->i_ino = objectid;
+ inode_set_bytes(inode, 0);
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ fill_inode_item(trans, path->nodes[0], inode_item, inode);
+
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+ struct btrfs_inode_ref);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_free_path(path);
+
+ location = &BTRFS_I(inode)->location;
+ location->objectid = objectid;
+ location->offset = 0;
+ btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+
+ insert_inode_hash(inode);
+ return inode;
+fail:
+ if (dir)
+ BTRFS_I(dir)->index_cnt--;
+ btrfs_free_path(path);
+ return ERR_PTR(ret);
+}
+
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
+/*
+ * utility function to add 'inode' into 'parent_inode' with
+ * a give name and a given sequence number.
+ * if 'add_backref' is true, also insert a backref from the
+ * inode to the parent directory.
+ */
+int btrfs_add_link(struct btrfs_trans_handle *trans,
+ struct inode *parent_inode, struct inode *inode,
+ const char *name, int name_len, int add_backref, u64 index)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_root *root = BTRFS_I(parent_inode)->root;
+
+ key.objectid = inode->i_ino;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ ret = btrfs_insert_dir_item(trans, root, name, name_len,
+ parent_inode->i_ino,
+ &key, btrfs_inode_type(inode),
+ index);
+ if (ret == 0) {
+ if (add_backref) {
+ ret = btrfs_insert_inode_ref(trans, root,
+ name, name_len,
+ inode->i_ino,
+ parent_inode->i_ino,
+ index);
+ }
+ btrfs_i_size_write(parent_inode, parent_inode->i_size +
+ name_len * 2);
+ parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode(trans, root, parent_inode);
+ }
+ return ret;
+}
+
+static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
+ struct dentry *dentry, struct inode *inode,
+ int backref, u64 index)
+{
+ int err = btrfs_add_link(trans, dentry->d_parent->d_inode,
+ inode, dentry->d_name.name,
+ dentry->d_name.len, backref, index);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ if (err > 0)
+ err = -EEXIST;
+ return err;
+}
+
+static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
+ int mode, dev_t rdev)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ unsigned long nr = 0;
+ u64 index = 0;
+
+ if (!new_valid_dev(rdev))
+ return -EINVAL;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino, objectid,
+ BTRFS_I(dir)->block_group, mode, &index);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode, 0, index);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_op = &btrfs_special_inode_operations;
+ init_special_inode(inode, inode->i_mode, rdev);
+ btrfs_update_inode(trans, root, inode);
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int btrfs_create(struct inode *dir, struct dentry *dentry,
+ int mode, struct nameidata *nd)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ unsigned long nr = 0;
+ u64 objectid;
+ u64 index = 0;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto fail;
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino,
+ objectid, BTRFS_I(dir)->block_group, mode,
+ &index);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode, 0, index);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = old_dentry->d_inode;
+ u64 index;
+ unsigned long nr = 0;
+ int err;
+ int drop_inode = 0;
+
+ if (inode->i_nlink == 0)
+ return -ENOENT;
+
+ btrfs_inc_nlink(inode);
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto fail;
+ err = btrfs_set_inode_index(dir, &index);
+ if (err)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, dir);
+ atomic_inc(&inode->i_count);
+
+ err = btrfs_add_nondir(trans, dentry, inode, 1, index);
+
+ if (err)
+ drop_inode = 1;
+
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, dir);
+ err = btrfs_update_inode(trans, root, inode);
+
+ if (err)
+ drop_inode = 1;
+
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct inode *inode = NULL;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int err = 0;
+ int drop_on_err = 0;
+ u64 objectid = 0;
+ u64 index = 0;
+ unsigned long nr = 1;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto out_unlock;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto out_unlock;
+ }
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino, objectid,
+ BTRFS_I(dir)->block_group, S_IFDIR | mode,
+ &index);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_fail;
+ }
+
+ drop_on_err = 1;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err)
+ goto out_fail;
+
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+ btrfs_set_trans_block_group(trans, inode);
+
+ btrfs_i_size_write(inode, 0);
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ goto out_fail;
+
+ err = btrfs_add_link(trans, dentry->d_parent->d_inode,
+ inode, dentry->d_name.name,
+ dentry->d_name.len, 0, index);
+ if (err)
+ goto out_fail;
+
+ d_instantiate(dentry, inode);
+ drop_on_err = 0;
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+
+out_fail:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+
+out_unlock:
+ if (drop_on_err)
+ iput(inode);
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+/* helper for btfs_get_extent. Given an existing extent in the tree,
+ * and an extent that you want to insert, deal with overlap and insert
+ * the new extent into the tree.
+ */
+static int merge_extent_mapping(struct extent_map_tree *em_tree,
+ struct extent_map *existing,
+ struct extent_map *em,
+ u64 map_start, u64 map_len)
+{
+ u64 start_diff;
+
+ BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
+ start_diff = map_start - em->start;
+ em->start = map_start;
+ em->len = map_len;
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+ em->block_start += start_diff;
+ em->block_len -= start_diff;
+ }
+ return add_extent_mapping(em_tree, em);
+}
+
+static noinline int uncompress_inline(struct btrfs_path *path,
+ struct inode *inode, struct page *page,
+ size_t pg_offset, u64 extent_offset,
+ struct btrfs_file_extent_item *item)
+{
+ int ret;
+ struct extent_buffer *leaf = path->nodes[0];
+ char *tmp;
+ size_t max_size;
+ unsigned long inline_size;
+ unsigned long ptr;
+
+ WARN_ON(pg_offset != 0);
+ max_size = btrfs_file_extent_ram_bytes(leaf, item);
+ inline_size = btrfs_file_extent_inline_item_len(leaf,
+ btrfs_item_nr(leaf, path->slots[0]));
+ tmp = kmalloc(inline_size, GFP_NOFS);
+ ptr = btrfs_file_extent_inline_start(item);
+
+ read_extent_buffer(leaf, tmp, ptr, inline_size);
+
+ max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
+ ret = btrfs_zlib_decompress(tmp, page, extent_offset,
+ inline_size, max_size);
+ if (ret) {
+ char *kaddr = kmap_atomic(page, KM_USER0);
+ unsigned long copy_size = min_t(u64,
+ PAGE_CACHE_SIZE - pg_offset,
+ max_size - extent_offset);
+ memset(kaddr + pg_offset, 0, copy_size);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ kfree(tmp);
+ return 0;
+}
+
+/*
+ * a bit scary, this does extent mapping from logical file offset to the disk.
+ * the ugly parts come from merging extents from the disk with the in-ram
+ * representation. This gets more complex because of the data=ordered code,
+ * where the in-ram extents might be locked pending data=ordered completion.
+ *
+ * This also copies inline extents directly into the page.
+ */
+
+struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
+ size_t pg_offset, u64 start, u64 len,
+ int create)
+{
+ int ret;
+ int err = 0;
+ u64 bytenr;
+ u64 extent_start = 0;
+ u64 extent_end = 0;
+ u64 objectid = inode->i_ino;
+ u32 found_type;
+ struct btrfs_path *path = NULL;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *item;
+ struct extent_buffer *leaf;
+ struct btrfs_key found_key;
+ struct extent_map *em = NULL;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_trans_handle *trans = NULL;
+ int compressed;
+
+again:
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (em)
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ spin_unlock(&em_tree->lock);
+
+ if (em) {
+ if (em->start > start || em->start + em->len <= start)
+ free_extent_map(em);
+ else if (em->block_start == EXTENT_MAP_INLINE && page)
+ free_extent_map(em);
+ else
+ goto out;
+ }
+ em = alloc_extent_map(GFP_NOFS);
+ if (!em) {
+ err = -ENOMEM;
+ goto out;
+ }
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ em->start = EXTENT_MAP_HOLE;
+ em->orig_start = EXTENT_MAP_HOLE;
+ em->len = (u64)-1;
+ em->block_len = (u64)-1;
+
+ if (!path) {
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ }
+
+ ret = btrfs_lookup_file_extent(trans, root, path,
+ objectid, start, trans != NULL);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+
+ if (ret != 0) {
+ if (path->slots[0] == 0)
+ goto not_found;
+ path->slots[0]--;
+ }
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ /* are we inside the extent that was found? */
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ found_type = btrfs_key_type(&found_key);
+ if (found_key.objectid != objectid ||
+ found_type != BTRFS_EXTENT_DATA_KEY) {
+ goto not_found;
+ }
+
+ found_type = btrfs_file_extent_type(leaf, item);
+ extent_start = found_key.offset;
+ compressed = btrfs_file_extent_compression(leaf, item);
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ extent_end = extent_start +
+ btrfs_file_extent_num_bytes(leaf, item);
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ size_t size;
+ size = btrfs_file_extent_inline_len(leaf, item);
+ extent_end = (extent_start + size + root->sectorsize - 1) &
+ ~((u64)root->sectorsize - 1);
+ }
+
+ if (start >= extent_end) {
+ path->slots[0]++;
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ if (ret > 0)
+ goto not_found;
+ leaf = path->nodes[0];
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != objectid ||
+ found_key.type != BTRFS_EXTENT_DATA_KEY)
+ goto not_found;
+ if (start + len <= found_key.offset)
+ goto not_found;
+ em->start = start;
+ em->len = found_key.offset - start;
+ goto not_found_em;
+ }
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ em->start = extent_start;
+ em->len = extent_end - extent_start;
+ em->orig_start = extent_start -
+ btrfs_file_extent_offset(leaf, item);
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
+ if (bytenr == 0) {
+ em->block_start = EXTENT_MAP_HOLE;
+ goto insert;
+ }
+ if (compressed) {
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ em->block_start = bytenr;
+ em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
+ item);
+ } else {
+ bytenr += btrfs_file_extent_offset(leaf, item);
+ em->block_start = bytenr;
+ em->block_len = em->len;
+ if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
+ set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
+ }
+ goto insert;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ unsigned long ptr;
+ char *map;
+ size_t size;
+ size_t extent_offset;
+ size_t copy_size;
+
+ em->block_start = EXTENT_MAP_INLINE;
+ if (!page || create) {
+ em->start = extent_start;
+ em->len = extent_end - extent_start;
+ goto out;
+ }
+
+ size = btrfs_file_extent_inline_len(leaf, item);
+ extent_offset = page_offset(page) + pg_offset - extent_start;
+ copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
+ size - extent_offset);
+ em->start = extent_start + extent_offset;
+ em->len = (copy_size + root->sectorsize - 1) &
+ ~((u64)root->sectorsize - 1);
+ em->orig_start = EXTENT_MAP_INLINE;
+ if (compressed)
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ ptr = btrfs_file_extent_inline_start(item) + extent_offset;
+ if (create == 0 && !PageUptodate(page)) {
+ if (btrfs_file_extent_compression(leaf, item) ==
+ BTRFS_COMPRESS_ZLIB) {
+ ret = uncompress_inline(path, inode, page,
+ pg_offset,
+ extent_offset, item);
+ BUG_ON(ret);
+ } else {
+ map = kmap(page);
+ read_extent_buffer(leaf, map + pg_offset, ptr,
+ copy_size);
+ kunmap(page);
+ }
+ flush_dcache_page(page);
+ } else if (create && PageUptodate(page)) {
+ if (!trans) {
+ kunmap(page);
+ free_extent_map(em);
+ em = NULL;
+ btrfs_release_path(root, path);
+ trans = btrfs_join_transaction(root, 1);
+ goto again;
+ }
+ map = kmap(page);
+ write_extent_buffer(leaf, map + pg_offset, ptr,
+ copy_size);
+ kunmap(page);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ set_extent_uptodate(io_tree, em->start,
+ extent_map_end(em) - 1, GFP_NOFS);
+ goto insert;
+ } else {
+ printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
+ WARN_ON(1);
+ }
+not_found:
+ em->start = start;
+ em->len = len;
+not_found_em:
+ em->block_start = EXTENT_MAP_HOLE;
+ set_bit(EXTENT_FLAG_VACANCY, &em->flags);
+insert:
+ btrfs_release_path(root, path);
+ if (em->start > start || extent_map_end(em) <= start) {
+ printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
+ "[%llu %llu]\n", (unsigned long long)em->start,
+ (unsigned long long)em->len,
+ (unsigned long long)start,
+ (unsigned long long)len);
+ err = -EIO;
+ goto out;
+ }
+
+ err = 0;
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ /* it is possible that someone inserted the extent into the tree
+ * while we had the lock dropped. It is also possible that
+ * an overlapping map exists in the tree
+ */
+ if (ret == -EEXIST) {
+ struct extent_map *existing;
+
+ ret = 0;
+
+ existing = lookup_extent_mapping(em_tree, start, len);
+ if (existing && (existing->start > start ||
+ existing->start + existing->len <= start)) {
+ free_extent_map(existing);
+ existing = NULL;
+ }
+ if (!existing) {
+ existing = lookup_extent_mapping(em_tree, em->start,
+ em->len);
+ if (existing) {
+ err = merge_extent_mapping(em_tree, existing,
+ em, start,
+ root->sectorsize);
+ free_extent_map(existing);
+ if (err) {
+ free_extent_map(em);
+ em = NULL;
+ }
+ } else {
+ err = -EIO;
+ free_extent_map(em);
+ em = NULL;
+ }
+ } else {
+ free_extent_map(em);
+ em = existing;
+ err = 0;
+ }
+ }
+ spin_unlock(&em_tree->lock);
+out:
+ if (path)
+ btrfs_free_path(path);
+ if (trans) {
+ ret = btrfs_end_transaction(trans, root);
+ if (!err)
+ err = ret;
+ }
+ if (err) {
+ free_extent_map(em);
+ WARN_ON(1);
+ return ERR_PTR(err);
+ }
+ return em;
+}
+
+static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
+ const struct iovec *iov, loff_t offset,
+ unsigned long nr_segs)
+{
+ return -EINVAL;
+}
+
+static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
+{
+ return extent_bmap(mapping, iblock, btrfs_get_extent);
+}
+
+int btrfs_readpage(struct file *file, struct page *page)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_read_full_page(tree, page, btrfs_get_extent);
+}
+
+static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+
+
+ if (current->flags & PF_MEMALLOC) {
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+ }
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
+}
+
+int btrfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
+}
+
+static int
+btrfs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_readpages(tree, mapping, pages, nr_pages,
+ btrfs_get_extent);
+}
+static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ struct extent_io_tree *tree;
+ struct extent_map_tree *map;
+ int ret;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ map = &BTRFS_I(page->mapping->host)->extent_tree;
+ ret = try_release_extent_mapping(map, tree, page, gfp_flags);
+ if (ret == 1) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+ return ret;
+}
+
+static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ if (PageWriteback(page) || PageDirty(page))
+ return 0;
+ return __btrfs_releasepage(page, gfp_flags);
+}
+
+static void btrfs_invalidatepage(struct page *page, unsigned long offset)
+{
+ struct extent_io_tree *tree;
+ struct btrfs_ordered_extent *ordered;
+ u64 page_start = page_offset(page);
+ u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ wait_on_page_writeback(page);
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ if (offset) {
+ btrfs_releasepage(page, GFP_NOFS);
+ return;
+ }
+
+ lock_extent(tree, page_start, page_end, GFP_NOFS);
+ ordered = btrfs_lookup_ordered_extent(page->mapping->host,
+ page_offset(page));
+ if (ordered) {
+ /*
+ * IO on this page will never be started, so we need
+ * to account for any ordered extents now
+ */
+ clear_extent_bit(tree, page_start, page_end,
+ EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_LOCKED, 1, 0, GFP_NOFS);
+ btrfs_finish_ordered_io(page->mapping->host,
+ page_start, page_end);
+ btrfs_put_ordered_extent(ordered);
+ lock_extent(tree, page_start, page_end, GFP_NOFS);
+ }
+ clear_extent_bit(tree, page_start, page_end,
+ EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_ORDERED,
+ 1, 1, GFP_NOFS);
+ __btrfs_releasepage(page, GFP_NOFS);
+
+ ClearPageChecked(page);
+ if (PagePrivate(page)) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+}
+
+/*
+ * btrfs_page_mkwrite() is not allowed to change the file size as it gets
+ * called from a page fault handler when a page is first dirtied. Hence we must
+ * be careful to check for EOF conditions here. We set the page up correctly
+ * for a written page which means we get ENOSPC checking when writing into
+ * holes and correct delalloc and unwritten extent mapping on filesystems that
+ * support these features.
+ *
+ * We are not allowed to take the i_mutex here so we have to play games to
+ * protect against truncate races as the page could now be beyond EOF. Because
+ * vmtruncate() writes the inode size before removing pages, once we have the
+ * page lock we can determine safely if the page is beyond EOF. If it is not
+ * beyond EOF, then the page is guaranteed safe against truncation until we
+ * unlock the page.
+ */
+int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+ struct inode *inode = fdentry(vma->vm_file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ char *kaddr;
+ unsigned long zero_start;
+ loff_t size;
+ int ret;
+ u64 page_start;
+ u64 page_end;
+
+ ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
+ if (ret)
+ goto out;
+
+ ret = -EINVAL;
+again:
+ lock_page(page);
+ size = i_size_read(inode);
+ page_start = page_offset(page);
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ if ((page->mapping != inode->i_mapping) ||
+ (page_start >= size)) {
+ /* page got truncated out from underneath us */
+ goto out_unlock;
+ }
+ wait_on_page_writeback(page);
+
+ lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ set_page_extent_mapped(page);
+
+ /*
+ * we can't set the delalloc bits if there are pending ordered
+ * extents. Drop our locks and wait for them to finish
+ */
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ ret = 0;
+
+ /* page is wholly or partially inside EOF */
+ if (page_start + PAGE_CACHE_SIZE > size)
+ zero_start = size & ~PAGE_CACHE_MASK;
+ else
+ zero_start = PAGE_CACHE_SIZE;
+
+ if (zero_start != PAGE_CACHE_SIZE) {
+ kaddr = kmap(page);
+ memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
+ flush_dcache_page(page);
+ kunmap(page);
+ }
+ ClearPageChecked(page);
+ set_page_dirty(page);
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+out_unlock:
+ unlock_page(page);
+out:
+ return ret;
+}
+
+static void btrfs_truncate(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+ u64 mask = root->sectorsize - 1;
+
+ if (!S_ISREG(inode->i_mode))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+
+ btrfs_truncate_page(inode->i_mapping, inode->i_size);
+ btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ btrfs_i_size_write(inode, inode->i_size);
+
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret)
+ goto out;
+ /* FIXME, add redo link to tree so we don't leak on crash */
+ ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size,
+ BTRFS_EXTENT_DATA_KEY);
+ btrfs_update_inode(trans, root, inode);
+
+ ret = btrfs_orphan_del(trans, inode);
+ BUG_ON(ret);
+
+out:
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction_throttle(trans, root);
+ BUG_ON(ret);
+ btrfs_btree_balance_dirty(root, nr);
+}
+
+/*
+ * create a new subvolume directory/inode (helper for the ioctl).
+ */
+int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *new_root, struct dentry *dentry,
+ u64 new_dirid, u64 alloc_hint)
+{
+ struct inode *inode;
+ int error;
+ u64 index = 0;
+
+ inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
+ new_dirid, alloc_hint, S_IFDIR | 0700, &index);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+
+ inode->i_nlink = 1;
+ btrfs_i_size_write(inode, 0);
+
+ error = btrfs_update_inode(trans, new_root, inode);
+ if (error)
+ return error;
+
+ d_instantiate(dentry, inode);
+ return 0;
+}
+
+/* helper function for file defrag and space balancing. This
+ * forces readahead on a given range of bytes in an inode
+ */
+unsigned long btrfs_force_ra(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *file,
+ pgoff_t offset, pgoff_t last_index)
+{
+ pgoff_t req_size = last_index - offset + 1;
+
+ page_cache_sync_readahead(mapping, ra, file, offset, req_size);
+ return offset + req_size;
+}
+
+struct inode *btrfs_alloc_inode(struct super_block *sb)
+{
+ struct btrfs_inode *ei;
+
+ ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
+ if (!ei)
+ return NULL;
+ ei->last_trans = 0;
+ ei->logged_trans = 0;
+ btrfs_ordered_inode_tree_init(&ei->ordered_tree);
+ ei->i_acl = BTRFS_ACL_NOT_CACHED;
+ ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
+ INIT_LIST_HEAD(&ei->i_orphan);
+ return &ei->vfs_inode;
+}
+
+void btrfs_destroy_inode(struct inode *inode)
+{
+ struct btrfs_ordered_extent *ordered;
+ WARN_ON(!list_empty(&inode->i_dentry));
+ WARN_ON(inode->i_data.nrpages);
+
+ if (BTRFS_I(inode)->i_acl &&
+ BTRFS_I(inode)->i_acl != BTRFS_ACL_NOT_CACHED)
+ posix_acl_release(BTRFS_I(inode)->i_acl);
+ if (BTRFS_I(inode)->i_default_acl &&
+ BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
+ posix_acl_release(BTRFS_I(inode)->i_default_acl);
+
+ spin_lock(&BTRFS_I(inode)->root->list_lock);
+ if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
+ printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
+ " list\n", inode->i_ino);
+ dump_stack();
+ }
+ spin_unlock(&BTRFS_I(inode)->root->list_lock);
+
+ while (1) {
+ ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
+ if (!ordered)
+ break;
+ else {
+ printk(KERN_ERR "btrfs found ordered "
+ "extent %llu %llu on inode cleanup\n",
+ (unsigned long long)ordered->file_offset,
+ (unsigned long long)ordered->len);
+ btrfs_remove_ordered_extent(inode, ordered);
+ btrfs_put_ordered_extent(ordered);
+ btrfs_put_ordered_extent(ordered);
+ }
+ }
+ btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
+static void init_once(void *foo)
+{
+ struct btrfs_inode *ei = (struct btrfs_inode *) foo;
+
+ inode_init_once(&ei->vfs_inode);
+}
+
+void btrfs_destroy_cachep(void)
+{
+ if (btrfs_inode_cachep)
+ kmem_cache_destroy(btrfs_inode_cachep);
+ if (btrfs_trans_handle_cachep)
+ kmem_cache_destroy(btrfs_trans_handle_cachep);
+ if (btrfs_transaction_cachep)
+ kmem_cache_destroy(btrfs_transaction_cachep);
+ if (btrfs_bit_radix_cachep)
+ kmem_cache_destroy(btrfs_bit_radix_cachep);
+ if (btrfs_path_cachep)
+ kmem_cache_destroy(btrfs_path_cachep);
+}
+
+struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
+ unsigned long extra_flags,
+ void (*ctor)(void *))
+{
+ return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
+ SLAB_MEM_SPREAD | extra_flags), ctor);
+}
+
+int btrfs_init_cachep(void)
+{
+ btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
+ sizeof(struct btrfs_inode),
+ 0, init_once);
+ if (!btrfs_inode_cachep)
+ goto fail;
+ btrfs_trans_handle_cachep =
+ btrfs_cache_create("btrfs_trans_handle_cache",
+ sizeof(struct btrfs_trans_handle),
+ 0, NULL);
+ if (!btrfs_trans_handle_cachep)
+ goto fail;
+ btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
+ sizeof(struct btrfs_transaction),
+ 0, NULL);
+ if (!btrfs_transaction_cachep)
+ goto fail;
+ btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
+ sizeof(struct btrfs_path),
+ 0, NULL);
+ if (!btrfs_path_cachep)
+ goto fail;
+ btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
+ SLAB_DESTROY_BY_RCU, NULL);
+ if (!btrfs_bit_radix_cachep)
+ goto fail;
+ return 0;
+fail:
+ btrfs_destroy_cachep();
+ return -ENOMEM;
+}
+
+static int btrfs_getattr(struct vfsmount *mnt,
+ struct dentry *dentry, struct kstat *stat)
+{
+ struct inode *inode = dentry->d_inode;
+ generic_fillattr(inode, stat);
+ stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
+ stat->blksize = PAGE_CACHE_SIZE;
+ stat->blocks = (inode_get_bytes(inode) +
+ BTRFS_I(inode)->delalloc_bytes) >> 9;
+ return 0;
+}
+
+static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(old_dir)->root;
+ struct inode *new_inode = new_dentry->d_inode;
+ struct inode *old_inode = old_dentry->d_inode;
+ struct timespec ctime = CURRENT_TIME;
+ u64 index = 0;
+ int ret;
+
+ /* we're not allowed to rename between subvolumes */
+ if (BTRFS_I(old_inode)->root->root_key.objectid !=
+ BTRFS_I(new_dir)->root->root_key.objectid)
+ return -EXDEV;
+
+ if (S_ISDIR(old_inode->i_mode) && new_inode &&
+ new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
+ return -ENOTEMPTY;
+ }
+
+ /* to rename a snapshot or subvolume, we need to juggle the
+ * backrefs. This isn't coded yet
+ */
+ if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
+ return -EXDEV;
+
+ ret = btrfs_check_free_space(root, 1, 0);
+ if (ret)
+ goto out_unlock;
+
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, new_dir);
+
+ btrfs_inc_nlink(old_dentry->d_inode);
+ old_dir->i_ctime = old_dir->i_mtime = ctime;
+ new_dir->i_ctime = new_dir->i_mtime = ctime;
+ old_inode->i_ctime = ctime;
+
+ ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
+ old_dentry->d_name.name,
+ old_dentry->d_name.len);
+ if (ret)
+ goto out_fail;
+
+ if (new_inode) {
+ new_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_unlink_inode(trans, root, new_dir,
+ new_dentry->d_inode,
+ new_dentry->d_name.name,
+ new_dentry->d_name.len);
+ if (ret)
+ goto out_fail;
+ if (new_inode->i_nlink == 0) {
+ ret = btrfs_orphan_add(trans, new_dentry->d_inode);
+ if (ret)
+ goto out_fail;
+ }
+
+ }
+ ret = btrfs_set_inode_index(new_dir, &index);
+ if (ret)
+ goto out_fail;
+
+ ret = btrfs_add_link(trans, new_dentry->d_parent->d_inode,
+ old_inode, new_dentry->d_name.name,
+ new_dentry->d_name.len, 1, index);
+ if (ret)
+ goto out_fail;
+
+out_fail:
+ btrfs_end_transaction_throttle(trans, root);
+out_unlock:
+ return ret;
+}
+
+/*
+ * some fairly slow code that needs optimization. This walks the list
+ * of all the inodes with pending delalloc and forces them to disk.
+ */
+int btrfs_start_delalloc_inodes(struct btrfs_root *root)
+{
+ struct list_head *head = &root->fs_info->delalloc_inodes;
+ struct btrfs_inode *binode;
+ struct inode *inode;
+
+ if (root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ spin_lock(&root->fs_info->delalloc_lock);
+ while (!list_empty(head)) {
+ binode = list_entry(head->next, struct btrfs_inode,
+ delalloc_inodes);
+ inode = igrab(&binode->vfs_inode);
+ if (!inode)
+ list_del_init(&binode->delalloc_inodes);
+ spin_unlock(&root->fs_info->delalloc_lock);
+ if (inode) {
+ filemap_flush(inode->i_mapping);
+ iput(inode);
+ }
+ cond_resched();
+ spin_lock(&root->fs_info->delalloc_lock);
+ }
+ spin_unlock(&root->fs_info->delalloc_lock);
+
+ /* the filemap_flush will queue IO into the worker threads, but
+ * we have to make sure the IO is actually started and that
+ * ordered extents get created before we return
+ */
+ atomic_inc(&root->fs_info->async_submit_draining);
+ while (atomic_read(&root->fs_info->nr_async_submits) ||
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
+ atomic_read(&root->fs_info->async_delalloc_pages) == 0));
+ }
+ atomic_dec(&root->fs_info->async_submit_draining);
+ return 0;
+}
+
+static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ u64 index = 0 ;
+ int name_len;
+ int datasize;
+ unsigned long ptr;
+ struct btrfs_file_extent_item *ei;
+ struct extent_buffer *leaf;
+ unsigned long nr = 0;
+
+ name_len = strlen(symname) + 1;
+ if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
+ return -ENAMETOOLONG;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto out_fail;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino, objectid,
+ BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
+ &index);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode, 0, index);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+ if (drop_inode)
+ goto out_unlock;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ key.objectid = inode->i_ino;
+ key.offset = 0;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+ datasize = btrfs_file_extent_calc_inline_size(name_len);
+ err = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, ei, trans->transid);
+ btrfs_set_file_extent_type(leaf, ei,
+ BTRFS_FILE_EXTENT_INLINE);
+ btrfs_set_file_extent_encryption(leaf, ei, 0);
+ btrfs_set_file_extent_compression(leaf, ei, 0);
+ btrfs_set_file_extent_other_encoding(leaf, ei, 0);
+ btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
+
+ ptr = btrfs_file_extent_inline_start(ei);
+ write_extent_buffer(leaf, symname, ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode_set_bytes(inode, name_len);
+ btrfs_i_size_write(inode, name_len - 1);
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ drop_inode = 1;
+
+out_unlock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+out_fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
+ u64 alloc_hint, int mode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key ins;
+ u64 alloc_size;
+ u64 cur_offset = start;
+ u64 num_bytes = end - start;
+ int ret = 0;
+
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ while (num_bytes > 0) {
+ alloc_size = min(num_bytes, root->fs_info->max_extent);
+ ret = btrfs_reserve_extent(trans, root, alloc_size,
+ root->sectorsize, 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ if (ret) {
+ WARN_ON(1);
+ goto out;
+ }
+ ret = insert_reserved_file_extent(trans, inode,
+ cur_offset, ins.objectid,
+ ins.offset, ins.offset,
+ ins.offset, 0, 0, 0,
+ BTRFS_FILE_EXTENT_PREALLOC);
+ BUG_ON(ret);
+ num_bytes -= ins.offset;
+ cur_offset += ins.offset;
+ alloc_hint = ins.objectid + ins.offset;
+ }
+out:
+ if (cur_offset > start) {
+ inode->i_ctime = CURRENT_TIME;
+ btrfs_set_flag(inode, PREALLOC);
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ cur_offset > i_size_read(inode))
+ btrfs_i_size_write(inode, cur_offset);
+ ret = btrfs_update_inode(trans, root, inode);
+ BUG_ON(ret);
+ }
+
+ btrfs_end_transaction(trans, root);
+ return ret;
+}
+
+static long btrfs_fallocate(struct inode *inode, int mode,
+ loff_t offset, loff_t len)
+{
+ u64 cur_offset;
+ u64 last_byte;
+ u64 alloc_start;
+ u64 alloc_end;
+ u64 alloc_hint = 0;
+ u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
+ struct extent_map *em;
+ int ret;
+
+ alloc_start = offset & ~mask;
+ alloc_end = (offset + len + mask) & ~mask;
+
+ mutex_lock(&inode->i_mutex);
+ if (alloc_start > inode->i_size) {
+ ret = btrfs_cont_expand(inode, alloc_start);
+ if (ret)
+ goto out;
+ }
+
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+ lock_extent(&BTRFS_I(inode)->io_tree, alloc_start,
+ alloc_end - 1, GFP_NOFS);
+ ordered = btrfs_lookup_first_ordered_extent(inode,
+ alloc_end - 1);
+ if (ordered &&
+ ordered->file_offset + ordered->len > alloc_start &&
+ ordered->file_offset < alloc_end) {
+ btrfs_put_ordered_extent(ordered);
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ alloc_start, alloc_end - 1, GFP_NOFS);
+ btrfs_wait_ordered_range(inode, alloc_start,
+ alloc_end - alloc_start);
+ } else {
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ }
+
+ cur_offset = alloc_start;
+ while (1) {
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ alloc_end - cur_offset, 0);
+ BUG_ON(IS_ERR(em) || !em);
+ last_byte = min(extent_map_end(em), alloc_end);
+ last_byte = (last_byte + mask) & ~mask;
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ ret = prealloc_file_range(inode, cur_offset,
+ last_byte, alloc_hint, mode);
+ if (ret < 0) {
+ free_extent_map(em);
+ break;
+ }
+ }
+ if (em->block_start <= EXTENT_MAP_LAST_BYTE)
+ alloc_hint = em->block_start;
+ free_extent_map(em);
+
+ cur_offset = last_byte;
+ if (cur_offset >= alloc_end) {
+ ret = 0;
+ break;
+ }
+ }
+ unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, alloc_end - 1,
+ GFP_NOFS);
+out:
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
+
+static int btrfs_set_page_dirty(struct page *page)
+{
+ return __set_page_dirty_nobuffers(page);
+}
+
+static int btrfs_permission(struct inode *inode, int mask)
+{
+ if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
+ return -EACCES;
+ return generic_permission(inode, mask, btrfs_check_acl);
+}
+
+static struct inode_operations btrfs_dir_inode_operations = {
+ .getattr = btrfs_getattr,
+ .lookup = btrfs_lookup,
+ .create = btrfs_create,
+ .unlink = btrfs_unlink,
+ .link = btrfs_link,
+ .mkdir = btrfs_mkdir,
+ .rmdir = btrfs_rmdir,
+ .rename = btrfs_rename,
+ .symlink = btrfs_symlink,
+ .setattr = btrfs_setattr,
+ .mknod = btrfs_mknod,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .permission = btrfs_permission,
+};
+static struct inode_operations btrfs_dir_ro_inode_operations = {
+ .lookup = btrfs_lookup,
+ .permission = btrfs_permission,
+};
+static struct file_operations btrfs_dir_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .readdir = btrfs_real_readdir,
+ .unlocked_ioctl = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = btrfs_ioctl,
+#endif
+ .release = btrfs_release_file,
+ .fsync = btrfs_sync_file,
+};
+
+static struct extent_io_ops btrfs_extent_io_ops = {
+ .fill_delalloc = run_delalloc_range,
+ .submit_bio_hook = btrfs_submit_bio_hook,
+ .merge_bio_hook = btrfs_merge_bio_hook,
+ .readpage_end_io_hook = btrfs_readpage_end_io_hook,
+ .writepage_end_io_hook = btrfs_writepage_end_io_hook,
+ .writepage_start_hook = btrfs_writepage_start_hook,
+ .readpage_io_failed_hook = btrfs_io_failed_hook,
+ .set_bit_hook = btrfs_set_bit_hook,
+ .clear_bit_hook = btrfs_clear_bit_hook,
+};
+
+static struct address_space_operations btrfs_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .writepages = btrfs_writepages,
+ .readpages = btrfs_readpages,
+ .sync_page = block_sync_page,
+ .bmap = btrfs_bmap,
+ .direct_IO = btrfs_direct_IO,
+ .invalidatepage = btrfs_invalidatepage,
+ .releasepage = btrfs_releasepage,
+ .set_page_dirty = btrfs_set_page_dirty,
+};
+
+static struct address_space_operations btrfs_symlink_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .invalidatepage = btrfs_invalidatepage,
+ .releasepage = btrfs_releasepage,
+};
+
+static struct inode_operations btrfs_file_inode_operations = {
+ .truncate = btrfs_truncate,
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .permission = btrfs_permission,
+ .fallocate = btrfs_fallocate,
+};
+static struct inode_operations btrfs_special_inode_operations = {
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .permission = btrfs_permission,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+};
+static struct inode_operations btrfs_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
+ .permission = btrfs_permission,
+};