/*
* Punch hole ranged [offset,len) for the file given by ino and root.
*
* Unlink kernel punch_hole, which will not zero/free existing extent,
* instead it will return -EEXIST if there is any extents in the hole
* range.
*/
int btrfs_punch_hole(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 ino, u64 offset, u64 len)
{
struct btrfs_path *path;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_get_extent(NULL, root, path, ino, offset, len, 0);
if (ret < 0)
goto out;
if (ret == 0) {
ret = -EEXIST;
goto out;
}
ret = btrfs_insert_file_extent(trans, root, ino, offset, 0, 0, len);
out:
btrfs_free_path(path);
return ret;
}
static int test_hole_first(u32 sectorsize, u32 nodesize)
{
struct btrfs_fs_info *fs_info = NULL;
struct inode *inode = NULL;
struct btrfs_root *root = NULL;
struct extent_map *em = NULL;
int ret = -ENOMEM;
inode = btrfs_new_test_inode();
if (!inode) {
test_msg("Couldn't allocate inode\n");
return ret;
}
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
BTRFS_I(inode)->location.offset = 0;
fs_info = btrfs_alloc_dummy_fs_info();
if (!fs_info) {
test_msg("Couldn't allocate dummy fs info\n");
goto out;
}
root = btrfs_alloc_dummy_root(fs_info, sectorsize, nodesize);
if (IS_ERR(root)) {
test_msg("Couldn't allocate root\n");
goto out;
}
root->node = alloc_dummy_extent_buffer(NULL, nodesize, nodesize);
if (!root->node) {
test_msg("Couldn't allocate dummy buffer\n");
goto out;
}
extent_buffer_get(root->node);
btrfs_set_header_nritems(root->node, 0);
btrfs_set_header_level(root->node, 0);
BTRFS_I(inode)->root = root;
ret = -EINVAL;
/*
* Need a blank inode item here just so we don't confuse
* btrfs_get_extent.
*/
insert_inode_item_key(root);
insert_extent(root, sectorsize, sectorsize, sectorsize, 0, sectorsize,
sectorsize, BTRFS_FILE_EXTENT_REG, 0, 1);
em = btrfs_get_extent(inode, NULL, 0, 0, 2 * sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_HOLE) {
test_msg("Expected a hole, got %llu\n", em->block_start);
goto out;
}
if (em->start != 0 || em->len != sectorsize) {
test_msg("Unexpected extent wanted start 0 len %u, "
"got start %llu len %llu\n",
sectorsize, em->start, em->len);
goto out;
}
if (em->flags != vacancy_only) {
test_msg("Wrong flags, wanted %lu, have %lu\n", vacancy_only,
em->flags);
goto out;
}
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, sectorsize, 2 * sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != sectorsize) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != sectorsize || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %u len %u, "
"got start %llu len %llu\n",
sectorsize, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, wanted 0 got %lu\n",
em->flags);
goto out;
}
ret = 0;
out:
if (!IS_ERR(em))
free_extent_map(em);
iput(inode);
btrfs_free_dummy_root(root);
btrfs_free_dummy_fs_info(fs_info);
return ret;
}
static noinline int test_btrfs_get_extent(u32 sectorsize, u32 nodesize)
{
struct btrfs_fs_info *fs_info = NULL;
struct inode *inode = NULL;
struct btrfs_root *root = NULL;
struct extent_map *em = NULL;
u64 orig_start;
u64 disk_bytenr;
u64 offset;
int ret = -ENOMEM;
inode = btrfs_new_test_inode();
if (!inode) {
test_msg("Couldn't allocate inode\n");
return ret;
}
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
BTRFS_I(inode)->location.offset = 0;
fs_info = btrfs_alloc_dummy_fs_info();
if (!fs_info) {
test_msg("Couldn't allocate dummy fs info\n");
goto out;
}
root = btrfs_alloc_dummy_root(fs_info, sectorsize, nodesize);
if (IS_ERR(root)) {
test_msg("Couldn't allocate root\n");
goto out;
}
root->node = alloc_dummy_extent_buffer(NULL, nodesize, nodesize);
if (!root->node) {
test_msg("Couldn't allocate dummy buffer\n");
goto out;
}
/*
* We will just free a dummy node if it's ref count is 2 so we need an
* extra ref so our searches don't accidentally release our page.
*/
extent_buffer_get(root->node);
btrfs_set_header_nritems(root->node, 0);
btrfs_set_header_level(root->node, 0);
ret = -EINVAL;
/* First with no extents */
BTRFS_I(inode)->root = root;
em = btrfs_get_extent(inode, NULL, 0, 0, sectorsize, 0);
if (IS_ERR(em)) {
em = NULL;
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_HOLE) {
test_msg("Expected a hole, got %llu\n", em->block_start);
goto out;
}
if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
test_msg("Vacancy flag wasn't set properly\n");
goto out;
}
free_extent_map(em);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
/*
* All of the magic numbers are based on the mapping setup in
* setup_file_extents, so if you change anything there you need to
* update the comment and update the expected values below.
*/
setup_file_extents(root, sectorsize);
em = btrfs_get_extent(inode, NULL, 0, 0, (u64)-1, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_HOLE) {
test_msg("Expected a hole, got %llu\n", em->block_start);
goto out;
}
if (em->start != 0 || em->len != 5) {
test_msg("Unexpected extent wanted start 0 len 5, got start "
"%llu len %llu\n", em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_INLINE) {
test_msg("Expected an inline, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != (sectorsize - 5)) {
test_msg("Unexpected extent wanted start %llu len 1, got start "
"%llu len %llu\n", offset, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
/*
* We don't test anything else for inline since it doesn't get set
* unless we have a page for it to write into. Maybe we should change
* this?
*/
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_HOLE) {
test_msg("Expected a hole, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != 4) {
test_msg("Unexpected extent wanted start %llu len 4, got start "
"%llu len %llu\n", offset, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* Regular extent */
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize - 1) {
test_msg("Unexpected extent wanted start %llu len 4095, got "
"start %llu len %llu\n", offset, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* The next 3 are split extents */
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
disk_bytenr = em->block_start;
orig_start = em->start;
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_HOLE) {
test_msg("Expected a hole, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != 2 * sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, 2 * sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != orig_start) {
test_msg("Wrong orig offset, want %llu, have %llu\n",
orig_start, em->orig_start);
goto out;
}
disk_bytenr += (em->start - orig_start);
if (em->block_start != disk_bytenr) {
test_msg("Wrong block start, want %llu, have %llu\n",
disk_bytenr, em->block_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* Prealloc extent */
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != prealloc_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
prealloc_only, em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* The next 3 are a half written prealloc extent */
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != prealloc_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
prealloc_only, em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
disk_bytenr = em->block_start;
orig_start = em->start;
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_HOLE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != orig_start) {
test_msg("Unexpected orig offset, wanted %llu, have %llu\n",
orig_start, em->orig_start);
goto out;
}
if (em->block_start != (disk_bytenr + (em->start - em->orig_start))) {
test_msg("Unexpected block start, wanted %llu, have %llu\n",
disk_bytenr + (em->start - em->orig_start),
em->block_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != 2 * sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, 2 * sectorsize, em->start, em->len);
goto out;
}
if (em->flags != prealloc_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
prealloc_only, em->flags);
goto out;
}
if (em->orig_start != orig_start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", orig_start,
em->orig_start);
goto out;
}
if (em->block_start != (disk_bytenr + (em->start - em->orig_start))) {
test_msg("Unexpected block start, wanted %llu, have %llu\n",
disk_bytenr + (em->start - em->orig_start),
em->block_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* Now for the compressed extent */
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != 2 * sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u,"
"got start %llu len %llu\n",
offset, 2 * sectorsize, em->start, em->len);
goto out;
}
if (em->flags != compressed_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
compressed_only, em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n",
em->start, em->orig_start);
goto out;
}
if (em->compress_type != BTRFS_COMPRESS_ZLIB) {
test_msg("Unexpected compress type, wanted %d, got %d\n",
BTRFS_COMPRESS_ZLIB, em->compress_type);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* Split compressed extent */
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u,"
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != compressed_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
compressed_only, em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n",
em->start, em->orig_start);
goto out;
}
if (em->compress_type != BTRFS_COMPRESS_ZLIB) {
test_msg("Unexpected compress type, wanted %d, got %d\n",
BTRFS_COMPRESS_ZLIB, em->compress_type);
goto out;
}
disk_bytenr = em->block_start;
orig_start = em->start;
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != disk_bytenr) {
test_msg("Block start does not match, want %llu got %llu\n",
disk_bytenr, em->block_start);
goto out;
}
if (em->start != offset || em->len != 2 * sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, 2 * sectorsize, em->start, em->len);
goto out;
}
if (em->flags != compressed_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
compressed_only, em->flags);
goto out;
}
if (em->orig_start != orig_start) {
test_msg("Wrong orig offset, want %llu, have %llu\n",
em->start, orig_start);
goto out;
}
if (em->compress_type != BTRFS_COMPRESS_ZLIB) {
test_msg("Unexpected compress type, wanted %d, got %d\n",
BTRFS_COMPRESS_ZLIB, em->compress_type);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
/* A hole between regular extents but no hole extent */
em = btrfs_get_extent(inode, NULL, 0, offset + 6, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, 4096 * 1024, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start != EXTENT_MAP_HOLE) {
test_msg("Expected a hole extent, got %llu\n", em->block_start);
goto out;
}
/*
* Currently we just return a length that we requested rather than the
* length of the actual hole, if this changes we'll have to change this
* test.
*/
if (em->start != offset || em->len != 3 * sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u, "
"got start %llu len %llu\n",
offset, 3 * sectorsize, em->start, em->len);
goto out;
}
if (em->flags != vacancy_only) {
test_msg("Unexpected flags set, want %lu have %lu\n",
vacancy_only, em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
offset = em->start + em->len;
free_extent_map(em);
em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize, 0);
if (IS_ERR(em)) {
test_msg("Got an error when we shouldn't have\n");
goto out;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
test_msg("Expected a real extent, got %llu\n", em->block_start);
goto out;
}
if (em->start != offset || em->len != sectorsize) {
test_msg("Unexpected extent wanted start %llu len %u,"
"got start %llu len %llu\n",
offset, sectorsize, em->start, em->len);
goto out;
}
if (em->flags != 0) {
test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
goto out;
}
if (em->orig_start != em->start) {
test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
em->orig_start);
goto out;
}
ret = 0;
out:
if (!IS_ERR(em))
free_extent_map(em);
iput(inode);
btrfs_free_dummy_root(root);
btrfs_free_dummy_fs_info(fs_info);
return ret;
}
static int should_defrag_range(struct inode *inode, u64 start, u64 len,
int thresh, u64 *last_len, u64 *skip,
u64 *defrag_end)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 1;
if (thresh == 0)
thresh = 256 * 1024;
/*
* make sure that once we start defragging and extent, we keep on
* defragging it
*/
if (start < *defrag_end)
return 1;
*skip = 0;
/*
* hopefully we have this extent in the tree already, try without
* the full extent lock
*/
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
read_unlock(&em_tree->lock);
if (!em) {
/* get the big lock and read metadata off disk */
lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
if (IS_ERR(em))
return 0;
}
/* this will cover holes, and inline extents */
if (em->block_start >= EXTENT_MAP_LAST_BYTE)
ret = 0;
/*
* we hit a real extent, if it is big don't bother defragging it again
*/
if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
ret = 0;
/*
* last_len ends up being a counter of how many bytes we've defragged.
* every time we choose not to defrag an extent, we reset *last_len
* so that the next tiny extent will force a defrag.
*
* The end result of this is that tiny extents before a single big
* extent will force at least part of that big extent to be defragged.
*/
if (ret) {
*last_len += len;
*defrag_end = extent_map_end(em);
} else {
*last_len = 0;
*skip = extent_map_end(em);
*defrag_end = 0;
}
free_extent_map(em);
return ret;
}
