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868 lines
26 KiB
868 lines
26 KiB
// SPDX-License-Identifier: GPL-2.0 |
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|
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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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|
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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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|
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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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const u64 block_size = btrfs_inode_sectorsize(inode); |
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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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|
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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, |
|
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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|
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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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|
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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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|
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if (comp_type == BTRFS_COMPRESS_NONE) { |
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memcpy_to_page(page, 0, data_start, 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, 0, |
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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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char *map; |
|
|
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map = kmap(page); |
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memset(map + datal, 0, block_size - datal); |
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flush_dcache_page(page); |
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kunmap(page); |
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} |
|
|
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SetPageUptodate(page); |
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ClearPageChecked(page); |
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set_page_dirty(page); |
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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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/* |
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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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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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|
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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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* 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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/* |
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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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|
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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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set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(dst)->runtime_flags); |
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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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|
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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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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; |
|
char *buf = NULL; |
|
struct btrfs_key key; |
|
u32 nritems; |
|
int slot; |
|
int ret; |
|
const u64 len = olen_aligned; |
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u64 last_dest_end = destoff; |
|
|
|
ret = -ENOMEM; |
|
buf = kvmalloc(fs_info->nodesize, GFP_KERNEL); |
|
if (!buf) |
|
return ret; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) { |
|
kvfree(buf); |
|
return ret; |
|
} |
|
|
|
path->reada = READA_FORWARD; |
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/* Clone data */ |
|
key.objectid = btrfs_ino(BTRFS_I(src)); |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = off; |
|
|
|
while (1) { |
|
u64 next_key_min_offset = key.offset + 1; |
|
struct btrfs_file_extent_item *extent; |
|
u64 extent_gen; |
|
int type; |
|
u32 size; |
|
struct btrfs_key new_key; |
|
u64 disko = 0, diskl = 0; |
|
u64 datao = 0, datal = 0; |
|
u8 comp; |
|
u64 drop_start; |
|
|
|
/* Note the key will change type as we walk through the tree */ |
|
ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path, |
|
0, 0); |
|
if (ret < 0) |
|
goto out; |
|
/* |
|
* First search, if no extent item that starts at offset off was |
|
* found but the previous item is an extent item, it's possible |
|
* it might overlap our target range, therefore process it. |
|
*/ |
|
if (key.offset == off && ret > 0 && path->slots[0] > 0) { |
|
btrfs_item_key_to_cpu(path->nodes[0], &key, |
|
path->slots[0] - 1); |
|
if (key.type == BTRFS_EXTENT_DATA_KEY) |
|
path->slots[0]--; |
|
} |
|
|
|
nritems = btrfs_header_nritems(path->nodes[0]); |
|
process_slot: |
|
if (path->slots[0] >= nritems) { |
|
ret = btrfs_next_leaf(BTRFS_I(src)->root, path); |
|
if (ret < 0) |
|
goto out; |
|
if (ret > 0) |
|
break; |
|
nritems = btrfs_header_nritems(path->nodes[0]); |
|
} |
|
leaf = path->nodes[0]; |
|
slot = path->slots[0]; |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, slot); |
|
if (key.type > BTRFS_EXTENT_DATA_KEY || |
|
key.objectid != btrfs_ino(BTRFS_I(src))) |
|
break; |
|
|
|
ASSERT(key.type == BTRFS_EXTENT_DATA_KEY); |
|
|
|
extent = btrfs_item_ptr(leaf, slot, |
|
struct btrfs_file_extent_item); |
|
extent_gen = btrfs_file_extent_generation(leaf, extent); |
|
comp = btrfs_file_extent_compression(leaf, extent); |
|
type = btrfs_file_extent_type(leaf, extent); |
|
if (type == BTRFS_FILE_EXTENT_REG || |
|
type == BTRFS_FILE_EXTENT_PREALLOC) { |
|
disko = btrfs_file_extent_disk_bytenr(leaf, extent); |
|
diskl = btrfs_file_extent_disk_num_bytes(leaf, extent); |
|
datao = btrfs_file_extent_offset(leaf, extent); |
|
datal = btrfs_file_extent_num_bytes(leaf, extent); |
|
} else if (type == BTRFS_FILE_EXTENT_INLINE) { |
|
/* Take upper bound, may be compressed */ |
|
datal = btrfs_file_extent_ram_bytes(leaf, extent); |
|
} |
|
|
|
/* |
|
* 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]++; |
|
goto process_slot; |
|
} else if (key.offset >= off + len) { |
|
break; |
|
} |
|
next_key_min_offset = key.offset + datal; |
|
size = btrfs_item_size_nr(leaf, slot); |
|
read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, slot), |
|
size); |
|
|
|
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(inode, path, drop_start, |
|
new_key.offset + datal - 1, &clone_info, |
|
&trans); |
|
if (ret) |
|
goto out; |
|
} else if (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 (key.offset != 0 || datal > fs_info->sectorsize) |
|
return -EUCLEAN; |
|
|
|
ret = clone_copy_inline_extent(inode, path, &new_key, |
|
drop_start, datal, size, |
|
comp, buf, &trans); |
|
if (ret) |
|
goto out; |
|
} |
|
|
|
btrfs_release_path(path); |
|
|
|
/* |
|
* If this is a new extent update the last_reflink_trans of both |
|
* inodes. This is used by fsync to make sure it does not log |
|
* multiple checksum items with overlapping ranges. For older |
|
* extents we don't need to do it since inode logging skips the |
|
* checksums for older extents. Also ignore holes and inline |
|
* extents because they don't have checksums in the csum tree. |
|
*/ |
|
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)) |
|
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
|
&BTRFS_I(inode)->runtime_flags); |
|
|
|
ret = btrfs_replace_file_extents(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 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; |
|
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; |
|
|
|
if (file_in->f_path.mnt != file_out->f_path.mnt || |
|
inode_in->i_sb != inode_out->i_sb) |
|
return -EXDEV; |
|
} |
|
|
|
/* 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); |
|
} |
|
|
|
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, 0); |
|
else |
|
lock_two_nondirectories(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, 0); |
|
else |
|
unlock_two_nondirectories(src_inode, dst_inode); |
|
|
|
return ret < 0 ? ret : len; |
|
}
|
|
|