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ae460f058e
The sb check is already done in do_clone_file_range, and the mnt check (which will hopefully go away in a subsequent patch) is done in ioctl_file_clone(). Remove the check in our code and put an ASSERT() to make sure it doesn't change underneath us. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
918 lines
28 KiB
C
918 lines
28 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/blkdev.h>
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#include <linux/iversion.h>
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#include "compression.h"
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#include "ctree.h"
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#include "delalloc-space.h"
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#include "reflink.h"
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#include "transaction.h"
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#include "subpage.h"
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#define BTRFS_MAX_DEDUPE_LEN SZ_16M
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static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
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struct inode *inode,
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u64 endoff,
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const u64 destoff,
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const u64 olen,
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int no_time_update)
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{
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struct btrfs_root *root = BTRFS_I(inode)->root;
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int ret;
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inode_inc_iversion(inode);
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if (!no_time_update)
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inode->i_mtime = inode->i_ctime = current_time(inode);
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/*
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* We round up to the block size at eof when determining which
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* extents to clone above, but shouldn't round up the file size.
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*/
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if (endoff > destoff + olen)
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endoff = destoff + olen;
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if (endoff > inode->i_size) {
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i_size_write(inode, endoff);
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btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
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}
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ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
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if (ret) {
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btrfs_abort_transaction(trans, ret);
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btrfs_end_transaction(trans);
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goto out;
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}
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ret = btrfs_end_transaction(trans);
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out:
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return ret;
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}
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static int copy_inline_to_page(struct btrfs_inode *inode,
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const u64 file_offset,
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char *inline_data,
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const u64 size,
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const u64 datal,
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const u8 comp_type)
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{
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struct btrfs_fs_info *fs_info = inode->root->fs_info;
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const u32 block_size = fs_info->sectorsize;
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const u64 range_end = file_offset + block_size - 1;
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const size_t inline_size = size - btrfs_file_extent_calc_inline_size(0);
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char *data_start = inline_data + btrfs_file_extent_calc_inline_size(0);
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struct extent_changeset *data_reserved = NULL;
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struct page *page = NULL;
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struct address_space *mapping = inode->vfs_inode.i_mapping;
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int ret;
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ASSERT(IS_ALIGNED(file_offset, block_size));
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/*
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* We have flushed and locked the ranges of the source and destination
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* inodes, we also have locked the inodes, so we are safe to do a
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* reservation here. Also we must not do the reservation while holding
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* a transaction open, otherwise we would deadlock.
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*/
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ret = btrfs_delalloc_reserve_space(inode, &data_reserved, file_offset,
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block_size);
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if (ret)
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goto out;
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page = find_or_create_page(mapping, file_offset >> PAGE_SHIFT,
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btrfs_alloc_write_mask(mapping));
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if (!page) {
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ret = -ENOMEM;
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goto out_unlock;
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}
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ret = set_page_extent_mapped(page);
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if (ret < 0)
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goto out_unlock;
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clear_extent_bit(&inode->io_tree, file_offset, range_end,
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EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
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0, 0, NULL);
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ret = btrfs_set_extent_delalloc(inode, file_offset, range_end, 0, NULL);
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if (ret)
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goto out_unlock;
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/*
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* After dirtying the page our caller will need to start a transaction,
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* and if we are low on metadata free space, that can cause flushing of
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* delalloc for all inodes in order to get metadata space released.
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* However we are holding the range locked for the whole duration of
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* the clone/dedupe operation, so we may deadlock if that happens and no
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* other task releases enough space. So mark this inode as not being
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* possible to flush to avoid such deadlock. We will clear that flag
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* when we finish cloning all extents, since a transaction is started
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* after finding each extent to clone.
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*/
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set_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &inode->runtime_flags);
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if (comp_type == BTRFS_COMPRESS_NONE) {
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memcpy_to_page(page, offset_in_page(file_offset), data_start,
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datal);
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flush_dcache_page(page);
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} else {
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ret = btrfs_decompress(comp_type, data_start, page,
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offset_in_page(file_offset),
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inline_size, datal);
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if (ret)
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goto out_unlock;
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flush_dcache_page(page);
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}
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/*
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* If our inline data is smaller then the block/page size, then the
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* remaining of the block/page is equivalent to zeroes. We had something
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* like the following done:
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*
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* $ xfs_io -f -c "pwrite -S 0xab 0 500" file
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* $ sync # (or fsync)
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* $ xfs_io -c "falloc 0 4K" file
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* $ xfs_io -c "pwrite -S 0xcd 4K 4K"
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*
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* So what's in the range [500, 4095] corresponds to zeroes.
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*/
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if (datal < block_size) {
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memzero_page(page, datal, block_size - datal);
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flush_dcache_page(page);
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}
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btrfs_page_set_uptodate(fs_info, page, file_offset, block_size);
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btrfs_page_clear_checked(fs_info, page, file_offset, block_size);
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btrfs_page_set_dirty(fs_info, page, file_offset, block_size);
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out_unlock:
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if (page) {
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unlock_page(page);
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put_page(page);
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}
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if (ret)
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btrfs_delalloc_release_space(inode, data_reserved, file_offset,
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block_size, true);
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btrfs_delalloc_release_extents(inode, block_size);
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out:
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extent_changeset_free(data_reserved);
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return ret;
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}
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/*
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* Deal with cloning of inline extents. We try to copy the inline extent from
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* the source inode to destination inode when possible. When not possible we
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* copy the inline extent's data into the respective page of the inode.
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*/
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static int clone_copy_inline_extent(struct inode *dst,
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struct btrfs_path *path,
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struct btrfs_key *new_key,
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const u64 drop_start,
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const u64 datal,
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const u64 size,
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const u8 comp_type,
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char *inline_data,
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struct btrfs_trans_handle **trans_out)
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{
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struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
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struct btrfs_root *root = BTRFS_I(dst)->root;
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const u64 aligned_end = ALIGN(new_key->offset + datal,
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fs_info->sectorsize);
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struct btrfs_trans_handle *trans = NULL;
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struct btrfs_drop_extents_args drop_args = { 0 };
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int ret;
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struct btrfs_key key;
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if (new_key->offset > 0) {
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ret = copy_inline_to_page(BTRFS_I(dst), new_key->offset,
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inline_data, size, datal, comp_type);
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goto out;
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}
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key.objectid = btrfs_ino(BTRFS_I(dst));
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key.type = BTRFS_EXTENT_DATA_KEY;
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key.offset = 0;
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ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
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if (ret < 0) {
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return ret;
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} else if (ret > 0) {
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if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
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ret = btrfs_next_leaf(root, path);
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if (ret < 0)
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return ret;
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else if (ret > 0)
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goto copy_inline_extent;
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}
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btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
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if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
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key.type == BTRFS_EXTENT_DATA_KEY) {
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/*
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* There's an implicit hole at file offset 0, copy the
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* inline extent's data to the page.
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*/
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ASSERT(key.offset > 0);
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goto copy_to_page;
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}
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} else if (i_size_read(dst) <= datal) {
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struct btrfs_file_extent_item *ei;
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ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
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struct btrfs_file_extent_item);
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/*
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* If it's an inline extent replace it with the source inline
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* extent, otherwise copy the source inline extent data into
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* the respective page at the destination inode.
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*/
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if (btrfs_file_extent_type(path->nodes[0], ei) ==
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BTRFS_FILE_EXTENT_INLINE)
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goto copy_inline_extent;
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goto copy_to_page;
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}
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copy_inline_extent:
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/*
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* We have no extent items, or we have an extent at offset 0 which may
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* or may not be inlined. All these cases are dealt the same way.
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*/
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if (i_size_read(dst) > datal) {
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/*
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* At the destination offset 0 we have either a hole, a regular
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* extent or an inline extent larger then the one we want to
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* clone. Deal with all these cases by copying the inline extent
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* data into the respective page at the destination inode.
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*/
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goto copy_to_page;
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}
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/*
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* Release path before starting a new transaction so we don't hold locks
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* that would confuse lockdep.
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*/
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btrfs_release_path(path);
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/*
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* If we end up here it means were copy the inline extent into a leaf
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* of the destination inode. We know we will drop or adjust at most one
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* extent item in the destination root.
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*
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* 1 unit - adjusting old extent (we may have to split it)
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* 1 unit - add new extent
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* 1 unit - inode update
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*/
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trans = btrfs_start_transaction(root, 3);
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if (IS_ERR(trans)) {
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ret = PTR_ERR(trans);
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trans = NULL;
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goto out;
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}
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drop_args.path = path;
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drop_args.start = drop_start;
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drop_args.end = aligned_end;
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drop_args.drop_cache = true;
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ret = btrfs_drop_extents(trans, root, BTRFS_I(dst), &drop_args);
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if (ret)
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goto out;
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ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
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if (ret)
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goto out;
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write_extent_buffer(path->nodes[0], inline_data,
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btrfs_item_ptr_offset(path->nodes[0],
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path->slots[0]),
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size);
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btrfs_update_inode_bytes(BTRFS_I(dst), datal, drop_args.bytes_found);
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btrfs_set_inode_full_sync(BTRFS_I(dst));
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ret = btrfs_inode_set_file_extent_range(BTRFS_I(dst), 0, aligned_end);
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out:
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if (!ret && !trans) {
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/*
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* No transaction here means we copied the inline extent into a
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* page of the destination inode.
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*
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* 1 unit to update inode item
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*/
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trans = btrfs_start_transaction(root, 1);
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if (IS_ERR(trans)) {
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ret = PTR_ERR(trans);
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trans = NULL;
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}
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}
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if (ret && trans) {
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btrfs_abort_transaction(trans, ret);
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btrfs_end_transaction(trans);
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}
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if (!ret)
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*trans_out = trans;
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return ret;
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copy_to_page:
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/*
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* Release our path because we don't need it anymore and also because
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* copy_inline_to_page() needs to reserve data and metadata, which may
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* need to flush delalloc when we are low on available space and
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* therefore cause a deadlock if writeback of an inline extent needs to
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* write to the same leaf or an ordered extent completion needs to write
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* to the same leaf.
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*/
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btrfs_release_path(path);
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ret = copy_inline_to_page(BTRFS_I(dst), new_key->offset,
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inline_data, size, datal, comp_type);
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goto out;
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}
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/**
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* btrfs_clone() - clone a range from inode file to another
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*
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* @src: Inode to clone from
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* @inode: Inode to clone to
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* @off: Offset within source to start clone from
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* @olen: Original length, passed by user, of range to clone
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* @olen_aligned: Block-aligned value of olen
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* @destoff: Offset within @inode to start clone
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* @no_time_update: Whether to update mtime/ctime on the target inode
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*/
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static int btrfs_clone(struct inode *src, struct inode *inode,
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const u64 off, const u64 olen, const u64 olen_aligned,
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const u64 destoff, int no_time_update)
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{
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struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
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struct btrfs_path *path = NULL;
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struct extent_buffer *leaf;
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struct btrfs_trans_handle *trans;
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char *buf = NULL;
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struct btrfs_key key;
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u32 nritems;
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int slot;
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int ret;
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const u64 len = olen_aligned;
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u64 last_dest_end = destoff;
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ret = -ENOMEM;
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buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
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if (!buf)
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return ret;
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path = btrfs_alloc_path();
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if (!path) {
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kvfree(buf);
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return ret;
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}
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path->reada = READA_FORWARD;
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/* Clone data */
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key.objectid = btrfs_ino(BTRFS_I(src));
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key.type = BTRFS_EXTENT_DATA_KEY;
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key.offset = off;
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while (1) {
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u64 next_key_min_offset = key.offset + 1;
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struct btrfs_file_extent_item *extent;
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u64 extent_gen;
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int type;
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u32 size;
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struct btrfs_key new_key;
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u64 disko = 0, diskl = 0;
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u64 datao = 0, datal = 0;
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u8 comp;
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u64 drop_start;
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|
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/* Note the key will change type as we walk through the tree */
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ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
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0, 0);
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if (ret < 0)
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goto out;
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/*
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* First search, if no extent item that starts at offset off was
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* found but the previous item is an extent item, it's possible
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* it might overlap our target range, therefore process it.
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*/
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if (key.offset == off && ret > 0 && path->slots[0] > 0) {
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btrfs_item_key_to_cpu(path->nodes[0], &key,
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path->slots[0] - 1);
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if (key.type == BTRFS_EXTENT_DATA_KEY)
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path->slots[0]--;
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}
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nritems = btrfs_header_nritems(path->nodes[0]);
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process_slot:
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if (path->slots[0] >= nritems) {
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ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
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if (ret < 0)
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goto out;
|
|
if (ret > 0)
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break;
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nritems = btrfs_header_nritems(path->nodes[0]);
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}
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leaf = path->nodes[0];
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slot = path->slots[0];
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|
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btrfs_item_key_to_cpu(leaf, &key, slot);
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if (key.type > BTRFS_EXTENT_DATA_KEY ||
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key.objectid != btrfs_ino(BTRFS_I(src)))
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break;
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|
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ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
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|
|
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extent = btrfs_item_ptr(leaf, slot,
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struct btrfs_file_extent_item);
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extent_gen = btrfs_file_extent_generation(leaf, extent);
|
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comp = btrfs_file_extent_compression(leaf, extent);
|
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type = btrfs_file_extent_type(leaf, extent);
|
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if (type == BTRFS_FILE_EXTENT_REG ||
|
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type == BTRFS_FILE_EXTENT_PREALLOC) {
|
|
disko = btrfs_file_extent_disk_bytenr(leaf, extent);
|
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diskl = btrfs_file_extent_disk_num_bytes(leaf, extent);
|
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datao = btrfs_file_extent_offset(leaf, extent);
|
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datal = btrfs_file_extent_num_bytes(leaf, extent);
|
|
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
|
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/* Take upper bound, may be compressed */
|
|
datal = btrfs_file_extent_ram_bytes(leaf, extent);
|
|
}
|
|
|
|
/*
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* The first search might have left us at an extent item that
|
|
* ends before our target range's start, can happen if we have
|
|
* holes and NO_HOLES feature enabled.
|
|
*/
|
|
if (key.offset + datal <= off) {
|
|
path->slots[0]++;
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|
goto process_slot;
|
|
} else if (key.offset >= off + len) {
|
|
break;
|
|
}
|
|
next_key_min_offset = key.offset + datal;
|
|
size = btrfs_item_size(leaf, slot);
|
|
read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, slot),
|
|
size);
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|
|
|
btrfs_release_path(path);
|
|
|
|
memcpy(&new_key, &key, sizeof(new_key));
|
|
new_key.objectid = btrfs_ino(BTRFS_I(inode));
|
|
if (off <= key.offset)
|
|
new_key.offset = key.offset + destoff - off;
|
|
else
|
|
new_key.offset = destoff;
|
|
|
|
/*
|
|
* Deal with a hole that doesn't have an extent item that
|
|
* represents it (NO_HOLES feature enabled).
|
|
* This hole is either in the middle of the cloning range or at
|
|
* the beginning (fully overlaps it or partially overlaps it).
|
|
*/
|
|
if (new_key.offset != last_dest_end)
|
|
drop_start = last_dest_end;
|
|
else
|
|
drop_start = new_key.offset;
|
|
|
|
if (type == BTRFS_FILE_EXTENT_REG ||
|
|
type == BTRFS_FILE_EXTENT_PREALLOC) {
|
|
struct btrfs_replace_extent_info clone_info;
|
|
|
|
/*
|
|
* a | --- range to clone ---| b
|
|
* | ------------- extent ------------- |
|
|
*/
|
|
|
|
/* Subtract range b */
|
|
if (key.offset + datal > off + len)
|
|
datal = off + len - key.offset;
|
|
|
|
/* Subtract range a */
|
|
if (off > key.offset) {
|
|
datao += off - key.offset;
|
|
datal -= off - key.offset;
|
|
}
|
|
|
|
clone_info.disk_offset = disko;
|
|
clone_info.disk_len = diskl;
|
|
clone_info.data_offset = datao;
|
|
clone_info.data_len = datal;
|
|
clone_info.file_offset = new_key.offset;
|
|
clone_info.extent_buf = buf;
|
|
clone_info.is_new_extent = false;
|
|
ret = btrfs_replace_file_extents(BTRFS_I(inode), path,
|
|
drop_start, new_key.offset + datal - 1,
|
|
&clone_info, &trans);
|
|
if (ret)
|
|
goto out;
|
|
} else {
|
|
ASSERT(type == BTRFS_FILE_EXTENT_INLINE);
|
|
/*
|
|
* Inline extents always have to start at file offset 0
|
|
* and can never be bigger then the sector size. We can
|
|
* never clone only parts of an inline extent, since all
|
|
* reflink operations must start at a sector size aligned
|
|
* offset, and the length must be aligned too or end at
|
|
* the i_size (which implies the whole inlined data).
|
|
*/
|
|
ASSERT(key.offset == 0);
|
|
ASSERT(datal <= fs_info->sectorsize);
|
|
if (WARN_ON(type != BTRFS_FILE_EXTENT_INLINE) ||
|
|
WARN_ON(key.offset != 0) ||
|
|
WARN_ON(datal > fs_info->sectorsize)) {
|
|
ret = -EUCLEAN;
|
|
goto out;
|
|
}
|
|
|
|
ret = clone_copy_inline_extent(inode, path, &new_key,
|
|
drop_start, datal, size,
|
|
comp, buf, &trans);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
btrfs_release_path(path);
|
|
|
|
/*
|
|
* Whenever we share an extent we update the last_reflink_trans
|
|
* of each inode to the current transaction. This is needed to
|
|
* make sure fsync does not log multiple checksum items with
|
|
* overlapping ranges (because some extent items might refer
|
|
* only to sections of the original extent). For the destination
|
|
* inode we do this regardless of the generation of the extents
|
|
* or even if they are inline extents or explicit holes, to make
|
|
* sure a full fsync does not skip them. For the source inode,
|
|
* we only need to update last_reflink_trans in case it's a new
|
|
* extent that is not a hole or an inline extent, to deal with
|
|
* the checksums problem on fsync.
|
|
*/
|
|
if (extent_gen == trans->transid && disko > 0)
|
|
BTRFS_I(src)->last_reflink_trans = trans->transid;
|
|
|
|
BTRFS_I(inode)->last_reflink_trans = trans->transid;
|
|
|
|
last_dest_end = ALIGN(new_key.offset + datal,
|
|
fs_info->sectorsize);
|
|
ret = clone_finish_inode_update(trans, inode, last_dest_end,
|
|
destoff, olen, no_time_update);
|
|
if (ret)
|
|
goto out;
|
|
if (new_key.offset + datal >= destoff + len)
|
|
break;
|
|
|
|
btrfs_release_path(path);
|
|
key.offset = next_key_min_offset;
|
|
|
|
if (fatal_signal_pending(current)) {
|
|
ret = -EINTR;
|
|
goto out;
|
|
}
|
|
|
|
cond_resched();
|
|
}
|
|
ret = 0;
|
|
|
|
if (last_dest_end < destoff + len) {
|
|
/*
|
|
* We have an implicit hole that fully or partially overlaps our
|
|
* cloning range at its end. This means that we either have the
|
|
* NO_HOLES feature enabled or the implicit hole happened due to
|
|
* mixing buffered and direct IO writes against this file.
|
|
*/
|
|
btrfs_release_path(path);
|
|
|
|
/*
|
|
* When using NO_HOLES and we are cloning a range that covers
|
|
* only a hole (no extents) into a range beyond the current
|
|
* i_size, punching a hole in the target range will not create
|
|
* an extent map defining a hole, because the range starts at or
|
|
* beyond current i_size. If the file previously had an i_size
|
|
* greater than the new i_size set by this clone operation, we
|
|
* need to make sure the next fsync is a full fsync, so that it
|
|
* detects and logs a hole covering a range from the current
|
|
* i_size to the new i_size. If the clone range covers extents,
|
|
* besides a hole, then we know the full sync flag was already
|
|
* set by previous calls to btrfs_replace_file_extents() that
|
|
* replaced file extent items.
|
|
*/
|
|
if (last_dest_end >= i_size_read(inode))
|
|
btrfs_set_inode_full_sync(BTRFS_I(inode));
|
|
|
|
ret = btrfs_replace_file_extents(BTRFS_I(inode), path,
|
|
last_dest_end, destoff + len - 1, NULL, &trans);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = clone_finish_inode_update(trans, inode, destoff + len,
|
|
destoff, olen, no_time_update);
|
|
}
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
kvfree(buf);
|
|
clear_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &BTRFS_I(inode)->runtime_flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
|
|
struct inode *inode2, u64 loff2, u64 len)
|
|
{
|
|
unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
|
|
unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
|
|
}
|
|
|
|
static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
|
|
struct inode *inode2, u64 loff2, u64 len)
|
|
{
|
|
if (inode1 < inode2) {
|
|
swap(inode1, inode2);
|
|
swap(loff1, loff2);
|
|
} else if (inode1 == inode2 && loff2 < loff1) {
|
|
swap(loff1, loff2);
|
|
}
|
|
lock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
|
|
lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
|
|
}
|
|
|
|
static void btrfs_double_mmap_lock(struct inode *inode1, struct inode *inode2)
|
|
{
|
|
if (inode1 < inode2)
|
|
swap(inode1, inode2);
|
|
down_write(&BTRFS_I(inode1)->i_mmap_lock);
|
|
down_write_nested(&BTRFS_I(inode2)->i_mmap_lock, SINGLE_DEPTH_NESTING);
|
|
}
|
|
|
|
static void btrfs_double_mmap_unlock(struct inode *inode1, struct inode *inode2)
|
|
{
|
|
up_write(&BTRFS_I(inode1)->i_mmap_lock);
|
|
up_write(&BTRFS_I(inode2)->i_mmap_lock);
|
|
}
|
|
|
|
static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
|
|
struct inode *dst, u64 dst_loff)
|
|
{
|
|
const u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
|
|
int ret;
|
|
|
|
/*
|
|
* Lock destination range to serialize with concurrent readpages() and
|
|
* source range to serialize with relocation.
|
|
*/
|
|
btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
|
|
ret = btrfs_clone(src, dst, loff, len, ALIGN(len, bs), dst_loff, 1);
|
|
btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
|
|
struct inode *dst, u64 dst_loff)
|
|
{
|
|
int ret = 0;
|
|
u64 i, tail_len, chunk_count;
|
|
struct btrfs_root *root_dst = BTRFS_I(dst)->root;
|
|
|
|
spin_lock(&root_dst->root_item_lock);
|
|
if (root_dst->send_in_progress) {
|
|
btrfs_warn_rl(root_dst->fs_info,
|
|
"cannot deduplicate to root %llu while send operations are using it (%d in progress)",
|
|
root_dst->root_key.objectid,
|
|
root_dst->send_in_progress);
|
|
spin_unlock(&root_dst->root_item_lock);
|
|
return -EAGAIN;
|
|
}
|
|
root_dst->dedupe_in_progress++;
|
|
spin_unlock(&root_dst->root_item_lock);
|
|
|
|
tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
|
|
chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
|
|
|
|
for (i = 0; i < chunk_count; i++) {
|
|
ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
|
|
dst, dst_loff);
|
|
if (ret)
|
|
goto out;
|
|
|
|
loff += BTRFS_MAX_DEDUPE_LEN;
|
|
dst_loff += BTRFS_MAX_DEDUPE_LEN;
|
|
}
|
|
|
|
if (tail_len > 0)
|
|
ret = btrfs_extent_same_range(src, loff, tail_len, dst, dst_loff);
|
|
out:
|
|
spin_lock(&root_dst->root_item_lock);
|
|
root_dst->dedupe_in_progress--;
|
|
spin_unlock(&root_dst->root_item_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
|
|
u64 off, u64 olen, u64 destoff)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct inode *src = file_inode(file_src);
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
int ret;
|
|
int wb_ret;
|
|
u64 len = olen;
|
|
u64 bs = fs_info->sb->s_blocksize;
|
|
|
|
/*
|
|
* VFS's generic_remap_file_range_prep() protects us from cloning the
|
|
* eof block into the middle of a file, which would result in corruption
|
|
* if the file size is not blocksize aligned. So we don't need to check
|
|
* for that case here.
|
|
*/
|
|
if (off + len == src->i_size)
|
|
len = ALIGN(src->i_size, bs) - off;
|
|
|
|
if (destoff > inode->i_size) {
|
|
const u64 wb_start = ALIGN_DOWN(inode->i_size, bs);
|
|
|
|
ret = btrfs_cont_expand(BTRFS_I(inode), inode->i_size, destoff);
|
|
if (ret)
|
|
return ret;
|
|
/*
|
|
* We may have truncated the last block if the inode's size is
|
|
* not sector size aligned, so we need to wait for writeback to
|
|
* complete before proceeding further, otherwise we can race
|
|
* with cloning and attempt to increment a reference to an
|
|
* extent that no longer exists (writeback completed right after
|
|
* we found the previous extent covering eof and before we
|
|
* attempted to increment its reference count).
|
|
*/
|
|
ret = btrfs_wait_ordered_range(inode, wb_start,
|
|
destoff - wb_start);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Lock destination range to serialize with concurrent readpages() and
|
|
* source range to serialize with relocation.
|
|
*/
|
|
btrfs_double_extent_lock(src, off, inode, destoff, len);
|
|
ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
|
|
btrfs_double_extent_unlock(src, off, inode, destoff, len);
|
|
|
|
/*
|
|
* We may have copied an inline extent into a page of the destination
|
|
* range, so wait for writeback to complete before truncating pages
|
|
* from the page cache. This is a rare case.
|
|
*/
|
|
wb_ret = btrfs_wait_ordered_range(inode, destoff, len);
|
|
ret = ret ? ret : wb_ret;
|
|
/*
|
|
* Truncate page cache pages so that future reads will see the cloned
|
|
* data immediately and not the previous data.
|
|
*/
|
|
truncate_inode_pages_range(&inode->i_data,
|
|
round_down(destoff, PAGE_SIZE),
|
|
round_up(destoff + len, PAGE_SIZE) - 1);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
loff_t *len, unsigned int remap_flags)
|
|
{
|
|
struct inode *inode_in = file_inode(file_in);
|
|
struct inode *inode_out = file_inode(file_out);
|
|
u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
|
|
bool same_inode = inode_out == inode_in;
|
|
u64 wb_len;
|
|
int ret;
|
|
|
|
if (!(remap_flags & REMAP_FILE_DEDUP)) {
|
|
struct btrfs_root *root_out = BTRFS_I(inode_out)->root;
|
|
|
|
if (btrfs_root_readonly(root_out))
|
|
return -EROFS;
|
|
|
|
ASSERT(inode_in->i_sb == inode_out->i_sb);
|
|
}
|
|
|
|
/* Don't make the dst file partly checksummed */
|
|
if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) !=
|
|
(BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Now that the inodes are locked, we need to start writeback ourselves
|
|
* and can not rely on the writeback from the VFS's generic helper
|
|
* generic_remap_file_range_prep() because:
|
|
*
|
|
* 1) For compression we must call filemap_fdatawrite_range() range
|
|
* twice (btrfs_fdatawrite_range() does it for us), and the generic
|
|
* helper only calls it once;
|
|
*
|
|
* 2) filemap_fdatawrite_range(), called by the generic helper only
|
|
* waits for the writeback to complete, i.e. for IO to be done, and
|
|
* not for the ordered extents to complete. We need to wait for them
|
|
* to complete so that new file extent items are in the fs tree.
|
|
*/
|
|
if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP))
|
|
wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs);
|
|
else
|
|
wb_len = ALIGN(*len, bs);
|
|
|
|
/*
|
|
* Since we don't lock ranges, wait for ongoing lockless dio writes (as
|
|
* any in progress could create its ordered extents after we wait for
|
|
* existing ordered extents below).
|
|
*/
|
|
inode_dio_wait(inode_in);
|
|
if (!same_inode)
|
|
inode_dio_wait(inode_out);
|
|
|
|
/*
|
|
* Workaround to make sure NOCOW buffered write reach disk as NOCOW.
|
|
*
|
|
* Btrfs' back references do not have a block level granularity, they
|
|
* work at the whole extent level.
|
|
* NOCOW buffered write without data space reserved may not be able
|
|
* to fall back to CoW due to lack of data space, thus could cause
|
|
* data loss.
|
|
*
|
|
* Here we take a shortcut by flushing the whole inode, so that all
|
|
* nocow write should reach disk as nocow before we increase the
|
|
* reference of the extent. We could do better by only flushing NOCOW
|
|
* data, but that needs extra accounting.
|
|
*
|
|
* Also we don't need to check ASYNC_EXTENT, as async extent will be
|
|
* CoWed anyway, not affecting nocow part.
|
|
*/
|
|
ret = filemap_flush(inode_in->i_mapping);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
|
|
wb_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs),
|
|
wb_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
|
|
len, remap_flags);
|
|
}
|
|
|
|
static bool file_sync_write(const struct file *file)
|
|
{
|
|
if (file->f_flags & (__O_SYNC | O_DSYNC))
|
|
return true;
|
|
if (IS_SYNC(file_inode(file)))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
|
|
struct file *dst_file, loff_t destoff, loff_t len,
|
|
unsigned int remap_flags)
|
|
{
|
|
struct inode *src_inode = file_inode(src_file);
|
|
struct inode *dst_inode = file_inode(dst_file);
|
|
bool same_inode = dst_inode == src_inode;
|
|
int ret;
|
|
|
|
if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
|
|
return -EINVAL;
|
|
|
|
if (same_inode) {
|
|
btrfs_inode_lock(src_inode, BTRFS_ILOCK_MMAP);
|
|
} else {
|
|
lock_two_nondirectories(src_inode, dst_inode);
|
|
btrfs_double_mmap_lock(src_inode, dst_inode);
|
|
}
|
|
|
|
ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
|
|
&len, remap_flags);
|
|
if (ret < 0 || len == 0)
|
|
goto out_unlock;
|
|
|
|
if (remap_flags & REMAP_FILE_DEDUP)
|
|
ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
|
|
else
|
|
ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
|
|
|
|
out_unlock:
|
|
if (same_inode) {
|
|
btrfs_inode_unlock(src_inode, BTRFS_ILOCK_MMAP);
|
|
} else {
|
|
btrfs_double_mmap_unlock(src_inode, dst_inode);
|
|
unlock_two_nondirectories(src_inode, dst_inode);
|
|
}
|
|
|
|
/*
|
|
* If either the source or the destination file was opened with O_SYNC,
|
|
* O_DSYNC or has the S_SYNC attribute, fsync both the destination and
|
|
* source files/ranges, so that after a successful return (0) followed
|
|
* by a power failure results in the reflinked data to be readable from
|
|
* both files/ranges.
|
|
*/
|
|
if (ret == 0 && len > 0 &&
|
|
(file_sync_write(src_file) || file_sync_write(dst_file))) {
|
|
ret = btrfs_sync_file(src_file, off, off + len - 1, 0);
|
|
if (ret == 0)
|
|
ret = btrfs_sync_file(dst_file, destoff,
|
|
destoff + len - 1, 0);
|
|
}
|
|
|
|
return ret < 0 ? ret : len;
|
|
}
|