blob: 0eeb5ea878948e129fe8824a68fe57d9b62a9e3c [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include "ctree.h"
#include "inode-item.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
int slot, const char *name,
int name_len)
{
struct btrfs_inode_ref *ref;
unsigned long ptr;
unsigned long name_ptr;
u32 item_size;
u32 cur_offset = 0;
int len;
item_size = btrfs_item_size(leaf, slot);
ptr = btrfs_item_ptr_offset(leaf, slot);
while (cur_offset < item_size) {
ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
len = btrfs_inode_ref_name_len(leaf, ref);
name_ptr = (unsigned long)(ref + 1);
cur_offset += len + sizeof(*ref);
if (len != name_len)
continue;
if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
return ref;
}
return NULL;
}
struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
struct extent_buffer *leaf, int slot, u64 ref_objectid,
const char *name, int name_len)
{
struct btrfs_inode_extref *extref;
unsigned long ptr;
unsigned long name_ptr;
u32 item_size;
u32 cur_offset = 0;
int ref_name_len;
item_size = btrfs_item_size(leaf, slot);
ptr = btrfs_item_ptr_offset(leaf, slot);
/*
* Search all extended backrefs in this item. We're only
* looking through any collisions so most of the time this is
* just going to compare against one buffer. If all is well,
* we'll return success and the inode ref object.
*/
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
name_ptr = (unsigned long)(&extref->name);
ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
if (ref_name_len == name_len &&
btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
(memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
return extref;
cur_offset += ref_name_len + sizeof(*extref);
}
return NULL;
}
/* Returns NULL if no extref found */
struct btrfs_inode_extref *
btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid, int ins_len,
int cow)
{
int ret;
struct btrfs_key key;
key.objectid = inode_objectid;
key.type = BTRFS_INODE_EXTREF_KEY;
key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
if (ret < 0)
return ERR_PTR(ret);
if (ret > 0)
return NULL;
return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
ref_objectid, name, name_len);
}
static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid,
u64 *index)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_extref *extref;
struct extent_buffer *leaf;
int ret;
int del_len = name_len + sizeof(*extref);
unsigned long ptr;
unsigned long item_start;
u32 item_size;
key.objectid = inode_objectid;
key.type = BTRFS_INODE_EXTREF_KEY;
key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
if (ret < 0)
goto out;
/*
* Sanity check - did we find the right item for this name?
* This should always succeed so error here will make the FS
* readonly.
*/
extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
ref_objectid, name, name_len);
if (!extref) {
btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
ret = -EROFS;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size(leaf, path->slots[0]);
if (index)
*index = btrfs_inode_extref_index(leaf, extref);
if (del_len == item_size) {
/*
* Common case only one ref in the item, remove the
* whole item.
*/
ret = btrfs_del_item(trans, root, path);
goto out;
}
ptr = (unsigned long)extref;
item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
memmove_extent_buffer(leaf, ptr, ptr + del_len,
item_size - (ptr + del_len - item_start));
btrfs_truncate_item(path, item_size - del_len, 1);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid, u64 *index)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_ref *ref;
struct extent_buffer *leaf;
unsigned long ptr;
unsigned long item_start;
u32 item_size;
u32 sub_item_len;
int ret;
int search_ext_refs = 0;
int del_len = name_len + sizeof(*ref);
key.objectid = inode_objectid;
key.offset = ref_objectid;
key.type = BTRFS_INODE_REF_KEY;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
ret = -ENOENT;
search_ext_refs = 1;
goto out;
} else if (ret < 0) {
goto out;
}
ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
name_len);
if (!ref) {
ret = -ENOENT;
search_ext_refs = 1;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size(leaf, path->slots[0]);
if (index)
*index = btrfs_inode_ref_index(leaf, ref);
if (del_len == item_size) {
ret = btrfs_del_item(trans, root, path);
goto out;
}
ptr = (unsigned long)ref;
sub_item_len = name_len + sizeof(*ref);
item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
item_size - (ptr + sub_item_len - item_start));
btrfs_truncate_item(path, item_size - sub_item_len, 1);
out:
btrfs_free_path(path);
if (search_ext_refs) {
/*
* No refs were found, or we could not find the
* name in our ref array. Find and remove the extended
* inode ref then.
*/
return btrfs_del_inode_extref(trans, root, name, name_len,
inode_objectid, ref_objectid, index);
}
return ret;
}
/*
* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
*
* The caller must have checked against BTRFS_LINK_MAX already.
*/
static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid, u64 index)
{
struct btrfs_inode_extref *extref;
int ret;
int ins_len = name_len + sizeof(*extref);
unsigned long ptr;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *leaf;
key.objectid = inode_objectid;
key.type = BTRFS_INODE_EXTREF_KEY;
key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_insert_empty_item(trans, root, path, &key,
ins_len);
if (ret == -EEXIST) {
if (btrfs_find_name_in_ext_backref(path->nodes[0],
path->slots[0],
ref_objectid,
name, name_len))
goto out;
btrfs_extend_item(path, ins_len);
ret = 0;
}
if (ret < 0)
goto out;
leaf = path->nodes[0];
ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len;
extref = (struct btrfs_inode_extref *)ptr;
btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
btrfs_set_inode_extref_index(path->nodes[0], extref, index);
btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
ptr = (unsigned long)&extref->name;
write_extent_buffer(path->nodes[0], name, ptr, name_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_free_path(path);
return ret;
}
/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid, u64 index)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_ref *ref;
unsigned long ptr;
int ret;
int ins_len = name_len + sizeof(*ref);
key.objectid = inode_objectid;
key.offset = ref_objectid;
key.type = BTRFS_INODE_REF_KEY;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->skip_release_on_error = 1;
ret = btrfs_insert_empty_item(trans, root, path, &key,
ins_len);
if (ret == -EEXIST) {
u32 old_size;
ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
name, name_len);
if (ref)
goto out;
old_size = btrfs_item_size(path->nodes[0], path->slots[0]);
btrfs_extend_item(path, ins_len);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_ref);
ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, index);
ptr = (unsigned long)(ref + 1);
ret = 0;
} else if (ret < 0) {
if (ret == -EOVERFLOW) {
if (btrfs_find_name_in_backref(path->nodes[0],
path->slots[0],
name, name_len))
ret = -EEXIST;
else
ret = -EMLINK;
}
goto out;
} else {
ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_ref);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, index);
ptr = (unsigned long)(ref + 1);
}
write_extent_buffer(path->nodes[0], name, ptr, name_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_free_path(path);
if (ret == -EMLINK) {
struct btrfs_super_block *disk_super = fs_info->super_copy;
/* We ran out of space in the ref array. Need to
* add an extended ref. */
if (btrfs_super_incompat_flags(disk_super)
& BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
ret = btrfs_insert_inode_extref(trans, root, name,
name_len,
inode_objectid,
ref_objectid, index);
}
return ret;
}
int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid)
{
struct btrfs_key key;
int ret;
key.objectid = objectid;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(struct btrfs_inode_item));
return ret;
}
int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path,
struct btrfs_key *location, int mod)
{
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
int ret;
int slot;
struct extent_buffer *leaf;
struct btrfs_key found_key;
ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
location->offset == (u64)-1 && path->slots[0] != 0) {
slot = path->slots[0] - 1;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid == location->objectid &&
found_key.type == location->type) {
path->slots[0]--;
return 0;
}
}
return ret;
}
static inline void btrfs_trace_truncate(struct btrfs_inode *inode,
struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi,
u64 offset, int extent_type, int slot)
{
if (!inode)
return;
if (extent_type == BTRFS_FILE_EXTENT_INLINE)
trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot,
offset);
else
trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset);
}
/*
* Remove inode items from a given root.
*
* @trans: A transaction handle.
* @root: The root from which to remove items.
* @inode: The inode whose items we want to remove.
* @control: The btrfs_truncate_control to control how and what we
* are truncating.
*
* Remove all keys associated with the inode from the given root that have a key
* with a type greater than or equals to @min_type. When @min_type has a value of
* BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value
* greater than or equals to @new_size. If a file extent item that starts before
* @new_size and ends after it is found, its length is adjusted.
*
* Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is
* BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block.
*/
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_truncate_control *control)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
struct btrfs_key found_key;
u64 new_size = control->new_size;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
u32 found_type = (u8)-1;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int ret;
u64 bytes_deleted = 0;
bool be_nice = false;
ASSERT(control->inode || !control->clear_extent_range);
ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY);
control->last_size = new_size;
control->sub_bytes = 0;
/*
* For shareable roots we want to back off from time to time, this turns
* out to be subvolume roots, reloc roots, and data reloc roots.
*/
if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
be_nice = true;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
key.objectid = control->ino;
key.offset = (u64)-1;
key.type = (u8)-1;
search_again:
/*
* With a 16K leaf size and 128MiB extents, you can actually queue up a
* huge file in a single leaf. Most of the time that bytes_deleted is
* > 0, it will be huge by the time we get here
*/
if (be_nice && bytes_deleted > SZ_32M &&
btrfs_should_end_transaction(trans)) {
ret = -EAGAIN;
goto out;
}
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
/* There are no items in the tree for us to truncate, we're done */
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
while (1) {
u64 clear_start = 0, clear_len = 0, extent_start = 0;
bool should_throttle = false;
fi = NULL;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != control->ino)
break;
if (found_type < control->min_type)
break;
item_end = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE)
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
item_end += btrfs_file_extent_ram_bytes(leaf, fi);
btrfs_trace_truncate(control->inode, leaf, fi,
found_key.offset, extent_type,
path->slots[0]);
item_end--;
}
if (found_type > control->min_type) {
del_item = 1;
} else {
if (item_end < new_size)
break;
if (found_key.offset >= new_size)
del_item = 1;
else
del_item = 0;
}
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
control->extents_found++;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
clear_start = found_key.offset;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = ALIGN(new_size -
found_key.offset,
fs_info->sectorsize);
clear_start = ALIGN(new_size, fs_info->sectorsize);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes - extent_num_bytes);
if (extent_start != 0)
control->sub_bytes += num_dec;
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
extent_offset = found_key.offset -
btrfs_file_extent_offset(leaf, fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_start != 0)
control->sub_bytes += num_dec;
}
clear_len = num_dec;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
/*
* We can't truncate inline items that have had
* special encodings
*/
if (!del_item &&
btrfs_file_extent_encryption(leaf, fi) == 0 &&
btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
btrfs_file_extent_compression(leaf, fi) == 0) {
u32 size = (u32)(new_size - found_key.offset);
btrfs_set_file_extent_ram_bytes(leaf, fi, size);
size = btrfs_file_extent_calc_inline_size(size);
btrfs_truncate_item(path, size, 1);
} else if (!del_item) {
/*
* We have to bail so the last_size is set to
* just before this extent.
*/
ret = BTRFS_NEED_TRUNCATE_BLOCK;
break;
} else {
/*
* Inline extents are special, we just treat
* them as a full sector worth in the file
* extent tree just for simplicity sake.
*/
clear_len = fs_info->sectorsize;
}
control->sub_bytes += item_end + 1 - new_size;
}
delete:
/*
* We only want to clear the file extent range if we're
* modifying the actual inode's mapping, which is just the
* normal truncate path.
*/
if (control->clear_extent_range) {
ret = btrfs_inode_clear_file_extent_range(control->inode,
clear_start, clear_len);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
}
if (del_item) {
ASSERT(!pending_del_nr ||
((path->slots[0] + 1) == pending_del_slot));
control->last_size = found_key.offset;
if (!pending_del_nr) {
/* No pending yet, add ourselves */
pending_del_slot = path->slots[0];
pending_del_nr = 1;
} else if (pending_del_nr &&
path->slots[0] + 1 == pending_del_slot) {
/* Hop on the pending chunk */
pending_del_nr++;
pending_del_slot = path->slots[0];
}
} else {
control->last_size = new_size;
break;
}
if (del_item && extent_start != 0 && !control->skip_ref_updates) {
struct btrfs_ref ref = { 0 };
bytes_deleted += extent_num_bytes;
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF,
extent_start, extent_num_bytes, 0);
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
control->ino, extent_offset,
root->root_key.objectid, false);
ret = btrfs_free_extent(trans, &ref);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
if (be_nice) {
if (btrfs_should_throttle_delayed_refs(trans))
should_throttle = true;
}
}
if (found_type == BTRFS_INODE_ITEM_KEY)
break;
if (path->slots[0] == 0 ||
path->slots[0] != pending_del_slot ||
should_throttle) {
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
pending_del_nr = 0;
}
btrfs_release_path(path);
/*
* We can generate a lot of delayed refs, so we need to
* throttle every once and a while and make sure we're
* adding enough space to keep up with the work we are
* generating. Since we hold a transaction here we
* can't flush, and we don't want to FLUSH_LIMIT because
* we could have generated too many delayed refs to
* actually allocate, so just bail if we're short and
* let the normal reservation dance happen higher up.
*/
if (should_throttle) {
ret = btrfs_delayed_refs_rsv_refill(fs_info,
BTRFS_RESERVE_NO_FLUSH);
if (ret) {
ret = -EAGAIN;
break;
}
}
goto search_again;
} else {
path->slots[0]--;
}
}
out:
if (ret >= 0 && pending_del_nr) {
int err;
err = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
if (err) {
btrfs_abort_transaction(trans, err);
ret = err;
}
}
ASSERT(control->last_size >= new_size);
if (!ret && control->last_size > new_size)
control->last_size = new_size;
btrfs_free_path(path);
return ret;
}