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btrfs: defrag: remove the old infrastructure
Now the old infrastructure can all be removed, defrag Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo
David Sterba
parent
7b508037d4
commit
c635757365
313
fs/btrfs/ioctl.c
313
fs/btrfs/ioctl.c
@ -986,107 +986,6 @@ out:
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return ret;
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}
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/*
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* When we're defragging a range, we don't want to kick it off again
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* if it is really just waiting for delalloc to send it down.
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* If we find a nice big extent or delalloc range for the bytes in the
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* file you want to defrag, we return 0 to let you know to skip this
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* part of the file
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*/
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static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
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{
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struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
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struct extent_map *em = NULL;
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struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
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const u32 sectorsize = btrfs_sb(inode->i_sb)->sectorsize;
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u64 end;
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read_lock(&em_tree->lock);
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em = lookup_extent_mapping(em_tree, offset, sectorsize);
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read_unlock(&em_tree->lock);
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if (em) {
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end = extent_map_end(em);
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free_extent_map(em);
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if (end - offset > thresh)
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return 0;
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}
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/* if we already have a nice delalloc here, just stop */
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thresh /= 2;
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end = count_range_bits(io_tree, &offset, offset + thresh,
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thresh, EXTENT_DELALLOC, 1);
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if (end >= thresh)
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return 0;
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return 1;
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}
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/*
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* helper function to walk through a file and find extents
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* newer than a specific transid, and smaller than thresh.
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*
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* This is used by the defragging code to find new and small
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* extents
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*/
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static int find_new_extents(struct btrfs_root *root,
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struct inode *inode, u64 newer_than,
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u64 *off, u32 thresh)
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{
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struct btrfs_path *path;
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struct btrfs_key min_key;
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struct extent_buffer *leaf;
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struct btrfs_file_extent_item *extent;
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int type;
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int ret;
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u64 ino = btrfs_ino(BTRFS_I(inode));
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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min_key.objectid = ino;
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min_key.type = BTRFS_EXTENT_DATA_KEY;
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min_key.offset = *off;
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while (1) {
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ret = btrfs_search_forward(root, &min_key, path, newer_than);
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if (ret != 0)
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goto none;
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process_slot:
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if (min_key.objectid != ino)
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goto none;
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if (min_key.type != BTRFS_EXTENT_DATA_KEY)
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goto none;
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leaf = path->nodes[0];
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extent = btrfs_item_ptr(leaf, path->slots[0],
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struct btrfs_file_extent_item);
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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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btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
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check_defrag_in_cache(inode, min_key.offset, thresh)) {
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*off = min_key.offset;
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btrfs_free_path(path);
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return 0;
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}
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path->slots[0]++;
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if (path->slots[0] < btrfs_header_nritems(leaf)) {
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btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
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goto process_slot;
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}
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if (min_key.offset == (u64)-1)
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goto none;
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min_key.offset++;
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btrfs_release_path(path);
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}
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none:
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btrfs_free_path(path);
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return -ENOENT;
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}
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static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start,
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bool locked)
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{
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@ -1142,66 +1041,6 @@ static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em,
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return ret;
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}
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static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
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u64 *last_len, u64 *skip, u64 *defrag_end,
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int compress)
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{
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struct extent_map *em;
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int ret = 1;
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bool next_mergeable = true;
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bool prev_mergeable = true;
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/*
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* make sure that once we start defragging an extent, we keep on
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* defragging it
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*/
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if (start < *defrag_end)
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return 1;
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*skip = 0;
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em = defrag_lookup_extent(inode, start, false);
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if (!em)
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return 0;
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/* this will cover holes, and inline extents */
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if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
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ret = 0;
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goto out;
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}
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if (!*defrag_end)
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prev_mergeable = false;
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next_mergeable = defrag_check_next_extent(inode, em, false);
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/*
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* we hit a real extent, if it is big or the next extent is not a
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* real extent, don't bother defragging it
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*/
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if (!compress && (*last_len == 0 || *last_len >= thresh) &&
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(em->len >= thresh || (!next_mergeable && !prev_mergeable)))
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ret = 0;
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out:
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/*
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* last_len ends up being a counter of how many bytes we've defragged.
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* every time we choose not to defrag an extent, we reset *last_len
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* so that the next tiny extent will force a defrag.
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*
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* The end result of this is that tiny extents before a single big
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* extent will force at least part of that big extent to be defragged.
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*/
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if (ret) {
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*defrag_end = extent_map_end(em);
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} else {
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*last_len = 0;
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*skip = extent_map_end(em);
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*defrag_end = 0;
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}
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free_extent_map(em);
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return ret;
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}
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/*
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* Prepare one page to be defragged.
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*
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@ -1284,158 +1123,6 @@ again:
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return page;
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}
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/*
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* it doesn't do much good to defrag one or two pages
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* at a time. This pulls in a nice chunk of pages
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* to COW and defrag.
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*
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* It also makes sure the delalloc code has enough
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* dirty data to avoid making new small extents as part
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* of the defrag
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*
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* It's a good idea to start RA on this range
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* before calling this.
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*/
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static int cluster_pages_for_defrag(struct inode *inode,
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struct page **pages,
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unsigned long start_index,
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unsigned long num_pages)
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{
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unsigned long file_end;
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u64 isize = i_size_read(inode);
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u64 page_start;
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u64 page_end;
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u64 page_cnt;
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u64 start = (u64)start_index << PAGE_SHIFT;
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u64 search_start;
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int ret;
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int i;
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int i_done;
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struct extent_state *cached_state = NULL;
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struct extent_changeset *data_reserved = NULL;
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file_end = (isize - 1) >> PAGE_SHIFT;
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if (!isize || start_index > file_end)
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return 0;
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page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
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ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
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start, page_cnt << PAGE_SHIFT);
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if (ret)
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return ret;
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i_done = 0;
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/* step one, lock all the pages */
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for (i = 0; i < page_cnt; i++) {
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struct page *page;
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page = defrag_prepare_one_page(BTRFS_I(inode), start_index + i);
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if (IS_ERR(page)) {
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ret = PTR_ERR(page);
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break;
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}
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pages[i] = page;
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i_done++;
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}
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if (!i_done || ret)
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goto out;
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if (!(inode->i_sb->s_flags & SB_ACTIVE))
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goto out;
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/*
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* Now we have a nice long stream of locked and up to date pages, let's
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* wait on them.
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*/
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for (i = 0; i < i_done; i++)
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wait_on_page_writeback(pages[i]);
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page_start = page_offset(pages[0]);
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page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
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lock_extent_bits(&BTRFS_I(inode)->io_tree,
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page_start, page_end - 1, &cached_state);
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/*
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* When defragmenting we skip ranges that have holes or inline extents,
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* (check should_defrag_range()), to avoid unnecessary IO and wasting
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* space. At btrfs_defrag_file(), we check if a range should be defragged
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* before locking the inode and then, if it should, we trigger a sync
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* page cache readahead - we lock the inode only after that to avoid
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* blocking for too long other tasks that possibly want to operate on
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* other file ranges. But before we were able to get the inode lock,
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* some other task may have punched a hole in the range, or we may have
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* now an inline extent, in which case we should not defrag. So check
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* for that here, where we have the inode and the range locked, and bail
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* out if that happened.
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*/
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search_start = page_start;
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while (search_start < page_end) {
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struct extent_map *em;
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em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, search_start,
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page_end - search_start);
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if (IS_ERR(em)) {
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ret = PTR_ERR(em);
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goto out_unlock_range;
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}
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if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
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free_extent_map(em);
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/* Ok, 0 means we did not defrag anything */
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ret = 0;
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goto out_unlock_range;
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}
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search_start = extent_map_end(em);
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free_extent_map(em);
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}
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clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
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page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
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EXTENT_DEFRAG, 0, 0, &cached_state);
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if (i_done != page_cnt) {
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spin_lock(&BTRFS_I(inode)->lock);
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btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
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spin_unlock(&BTRFS_I(inode)->lock);
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btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
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start, (page_cnt - i_done) << PAGE_SHIFT, true);
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}
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set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
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&cached_state);
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unlock_extent_cached(&BTRFS_I(inode)->io_tree,
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page_start, page_end - 1, &cached_state);
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for (i = 0; i < i_done; i++) {
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clear_page_dirty_for_io(pages[i]);
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ClearPageChecked(pages[i]);
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set_page_dirty(pages[i]);
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unlock_page(pages[i]);
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put_page(pages[i]);
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}
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btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
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extent_changeset_free(data_reserved);
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return i_done;
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out_unlock_range:
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unlock_extent_cached(&BTRFS_I(inode)->io_tree,
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page_start, page_end - 1, &cached_state);
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out:
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for (i = 0; i < i_done; i++) {
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unlock_page(pages[i]);
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put_page(pages[i]);
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}
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btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
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start, page_cnt << PAGE_SHIFT, true);
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btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
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extent_changeset_free(data_reserved);
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return ret;
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}
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struct defrag_target_range {
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struct list_head list;
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u64 start;
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