linux/fs/btrfs/file-item.c

1119 lines
31 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "volumes.h"
#include "print-tree.h"
#include "compression.h"
#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
sizeof(struct btrfs_item) * 2) / \
size) - 1))
#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
PAGE_SIZE))
/**
* @inode - the inode we want to update the disk_i_size for
* @new_i_size - the i_size we want to set to, 0 if we use i_size
*
* With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
* returns as it is perfectly fine with a file that has holes without hole file
* extent items.
*
* However without NO_HOLES we need to only return the area that is contiguous
* from the 0 offset of the file. Otherwise we could end up adjust i_size up
* to an extent that has a gap in between.
*
* Finally new_i_size should only be set in the case of truncate where we're not
* ready to use i_size_read() as the limiter yet.
*/
void btrfs_inode_safe_disk_i_size_write(struct inode *inode, u64 new_i_size)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
u64 start, end, i_size;
int ret;
i_size = new_i_size ?: i_size_read(inode);
if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
BTRFS_I(inode)->disk_i_size = i_size;
return;
}
spin_lock(&BTRFS_I(inode)->lock);
ret = find_contiguous_extent_bit(&BTRFS_I(inode)->file_extent_tree, 0,
&start, &end, EXTENT_DIRTY);
if (!ret && start == 0)
i_size = min(i_size, end + 1);
else
i_size = 0;
BTRFS_I(inode)->disk_i_size = i_size;
spin_unlock(&BTRFS_I(inode)->lock);
}
/**
* @inode - the inode we're modifying
* @start - the start file offset of the file extent we've inserted
* @len - the logical length of the file extent item
*
* Call when we are inserting a new file extent where there was none before.
* Does not need to call this in the case where we're replacing an existing file
* extent, however if not sure it's fine to call this multiple times.
*
* The start and len must match the file extent item, so thus must be sectorsize
* aligned.
*/
int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
u64 len)
{
if (len == 0)
return 0;
ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
return 0;
return set_extent_bits(&inode->file_extent_tree, start, start + len - 1,
EXTENT_DIRTY);
}
/**
* @inode - the inode we're modifying
* @start - the start file offset of the file extent we've inserted
* @len - the logical length of the file extent item
*
* Called when we drop a file extent, for example when we truncate. Doesn't
* need to be called for cases where we're replacing a file extent, like when
* we've COWed a file extent.
*
* The start and len must match the file extent item, so thus must be sectorsize
* aligned.
*/
int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
u64 len)
{
if (len == 0)
return 0;
ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
len == (u64)-1);
if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
return 0;
return clear_extent_bit(&inode->file_extent_tree, start,
start + len - 1, EXTENT_DIRTY, 0, 0, NULL);
}
static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
u16 csum_size)
{
u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
return ncsums * fs_info->sectorsize;
}
int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 pos,
u64 disk_offset, u64 disk_num_bytes,
u64 num_bytes, u64 offset, u64 ram_bytes,
u8 compression, u8 encryption, u16 other_encoding)
{
int ret = 0;
struct btrfs_file_extent_item *item;
struct btrfs_key file_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
file_key.objectid = objectid;
file_key.offset = pos;
file_key.type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
sizeof(*item));
if (ret < 0)
goto out;
BUG_ON(ret); /* Can't happen */
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
btrfs_set_file_extent_offset(leaf, item, offset);
btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
btrfs_set_file_extent_generation(leaf, item, trans->transid);
btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_compression(leaf, item, compression);
btrfs_set_file_extent_encryption(leaf, item, encryption);
btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return ret;
}
static struct btrfs_csum_item *
btrfs_lookup_csum(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, int cow)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
struct btrfs_key file_key;
struct btrfs_key found_key;
struct btrfs_csum_item *item;
struct extent_buffer *leaf;
u64 csum_offset = 0;
const u32 csum_size = fs_info->csum_size;
int csums_in_item;
file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
file_key.offset = bytenr;
file_key.type = BTRFS_EXTENT_CSUM_KEY;
ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
if (ret < 0)
goto fail;
leaf = path->nodes[0];
if (ret > 0) {
ret = 1;
if (path->slots[0] == 0)
goto fail;
path->slots[0]--;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
goto fail;
csum_offset = (bytenr - found_key.offset) >>
fs_info->sectorsize_bits;
csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
csums_in_item /= csum_size;
if (csum_offset == csums_in_item) {
ret = -EFBIG;
goto fail;
} else if (csum_offset > csums_in_item) {
goto fail;
}
}
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
item = (struct btrfs_csum_item *)((unsigned char *)item +
csum_offset * csum_size);
return item;
fail:
if (ret > 0)
ret = -ENOENT;
return ERR_PTR(ret);
}
int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid,
u64 offset, int mod)
{
int ret;
struct btrfs_key file_key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
file_key.objectid = objectid;
file_key.offset = offset;
file_key.type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
return ret;
}
/**
* btrfs_lookup_bio_sums - Look up checksums for a bio.
* @inode: inode that the bio is for.
* @bio: bio to look up.
* @offset: Unless (u64)-1, look up checksums for this offset in the file.
* If (u64)-1, use the page offsets from the bio instead.
* @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
* checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
* NULL, the checksum buffer is allocated and returned in
* btrfs_io_bio(bio)->csum instead.
*
* Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
*/
blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
u64 offset, u8 *dst)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct bio_vec bvec;
struct bvec_iter iter;
struct btrfs_csum_item *item = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_path *path;
const bool page_offsets = (offset == (u64)-1);
u8 *csum;
u64 item_start_offset = 0;
u64 item_last_offset = 0;
u64 disk_bytenr;
u64 page_bytes_left;
u32 diff;
int nblocks;
int count = 0;
const u32 csum_size = fs_info->csum_size;
if (!fs_info->csum_root || (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
return BLK_STS_OK;
path = btrfs_alloc_path();
if (!path)
return BLK_STS_RESOURCE;
nblocks = bio->bi_iter.bi_size >> fs_info->sectorsize_bits;
if (!dst) {
struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
GFP_NOFS);
if (!btrfs_bio->csum) {
btrfs_free_path(path);
return BLK_STS_RESOURCE;
}
} else {
btrfs_bio->csum = btrfs_bio->csum_inline;
}
csum = btrfs_bio->csum;
} else {
csum = dst;
}
if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
path->reada = READA_FORWARD;
/*
* the free space stuff is only read when it hasn't been
* updated in the current transaction. So, we can safely
* read from the commit root and sidestep a nasty deadlock
* between reading the free space cache and updating the csum tree.
*/
if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
path->search_commit_root = 1;
path->skip_locking = 1;
}
disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
bio_for_each_segment(bvec, bio, iter) {
page_bytes_left = bvec.bv_len;
if (count)
goto next;
if (page_offsets)
offset = page_offset(bvec.bv_page) + bvec.bv_offset;
count = btrfs_find_ordered_sum(BTRFS_I(inode), offset,
disk_bytenr, csum, nblocks);
if (count)
goto found;
if (!item || disk_bytenr < item_start_offset ||
disk_bytenr >= item_last_offset) {
struct btrfs_key found_key;
u32 item_size;
if (item)
btrfs_release_path(path);
item = btrfs_lookup_csum(NULL, fs_info->csum_root,
path, disk_bytenr, 0);
if (IS_ERR(item)) {
count = 1;
memset(csum, 0, csum_size);
if (BTRFS_I(inode)->root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
set_extent_bits(io_tree, offset,
offset + fs_info->sectorsize - 1,
EXTENT_NODATASUM);
} else {
btrfs_info_rl(fs_info,
"no csum found for inode %llu start %llu",
btrfs_ino(BTRFS_I(inode)), offset);
}
item = NULL;
btrfs_release_path(path);
goto found;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
item_start_offset = found_key.offset;
item_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
item_last_offset = item_start_offset +
(item_size / csum_size) *
fs_info->sectorsize;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_csum_item);
}
/*
* this byte range must be able to fit inside
* a single leaf so it will also fit inside a u32
*/
diff = disk_bytenr - item_start_offset;
diff = diff >> fs_info->sectorsize_bits;
diff = diff * csum_size;
count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
fs_info->sectorsize_bits);
read_extent_buffer(path->nodes[0], csum,
((unsigned long)item) + diff,
csum_size * count);
found:
csum += count * csum_size;
nblocks -= count;
next:
while (count > 0) {
count--;
disk_bytenr += fs_info->sectorsize;
offset += fs_info->sectorsize;
page_bytes_left -= fs_info->sectorsize;
if (!page_bytes_left)
break; /* move to next bio */
}
}
WARN_ON_ONCE(count);
btrfs_free_path(path);
return BLK_STS_OK;
}
int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
struct list_head *list, int search_commit)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_ordered_sum *sums;
struct btrfs_csum_item *item;
LIST_HEAD(tmplist);
unsigned long offset;
int ret;
size_t size;
u64 csum_end;
const u32 csum_size = fs_info->csum_size;
ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
IS_ALIGNED(end + 1, fs_info->sectorsize));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (search_commit) {
path->skip_locking = 1;
path->reada = READA_FORWARD;
path->search_commit_root = 1;
}
key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key.offset = start;
key.type = BTRFS_EXTENT_CSUM_KEY;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto fail;
if (ret > 0 && path->slots[0] > 0) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
key.type == BTRFS_EXTENT_CSUM_KEY) {
offset = (start - key.offset) >> fs_info->sectorsize_bits;
if (offset * csum_size <
btrfs_item_size_nr(leaf, path->slots[0] - 1))
path->slots[0]--;
}
}
while (start <= end) {
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto fail;
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
key.type != BTRFS_EXTENT_CSUM_KEY ||
key.offset > end)
break;
if (key.offset > start)
start = key.offset;
size = btrfs_item_size_nr(leaf, path->slots[0]);
csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
if (csum_end <= start) {
path->slots[0]++;
continue;
}
csum_end = min(csum_end, end + 1);
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_csum_item);
while (start < csum_end) {
size = min_t(size_t, csum_end - start,
max_ordered_sum_bytes(fs_info, csum_size));
sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
GFP_NOFS);
if (!sums) {
ret = -ENOMEM;
goto fail;
}
sums->bytenr = start;
sums->len = (int)size;
offset = (start - key.offset) >> fs_info->sectorsize_bits;
offset *= csum_size;
size >>= fs_info->sectorsize_bits;
read_extent_buffer(path->nodes[0],
sums->sums,
((unsigned long)item) + offset,
csum_size * size);
start += fs_info->sectorsize * size;
list_add_tail(&sums->list, &tmplist);
}
path->slots[0]++;
}
ret = 0;
fail:
while (ret < 0 && !list_empty(&tmplist)) {
sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
list_splice_tail(&tmplist, list);
btrfs_free_path(path);
return ret;
}
/*
* btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
* @inode: Owner of the data inside the bio
* @bio: Contains the data to be checksummed
* @file_start: offset in file this bio begins to describe
* @contig: Boolean. If true/1 means all bio vecs in this bio are
* contiguous and they begin at @file_start in the file. False/0
* means this bio can contains potentially discontigous bio vecs
* so the logical offset of each should be calculated separately.
*/
blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
u64 file_start, int contig)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
struct btrfs_ordered_sum *sums;
struct btrfs_ordered_extent *ordered = NULL;
char *data;
struct bvec_iter iter;
struct bio_vec bvec;
int index;
int nr_sectors;
unsigned long total_bytes = 0;
unsigned long this_sum_bytes = 0;
int i;
u64 offset;
unsigned nofs_flag;
nofs_flag = memalloc_nofs_save();
sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!sums)
return BLK_STS_RESOURCE;
sums->len = bio->bi_iter.bi_size;
INIT_LIST_HEAD(&sums->list);
if (contig)
offset = file_start;
else
offset = 0; /* shut up gcc */
sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
index = 0;
shash->tfm = fs_info->csum_shash;
bio_for_each_segment(bvec, bio, iter) {
if (!contig)
offset = page_offset(bvec.bv_page) + bvec.bv_offset;
if (!ordered) {
ordered = btrfs_lookup_ordered_extent(inode, offset);
BUG_ON(!ordered); /* Logic error */
}
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
bvec.bv_len + fs_info->sectorsize
- 1);
for (i = 0; i < nr_sectors; i++) {
if (offset >= ordered->file_offset + ordered->num_bytes ||
offset < ordered->file_offset) {
unsigned long bytes_left;
sums->len = this_sum_bytes;
this_sum_bytes = 0;
btrfs_add_ordered_sum(ordered, sums);
btrfs_put_ordered_extent(ordered);
bytes_left = bio->bi_iter.bi_size - total_bytes;
nofs_flag = memalloc_nofs_save();
sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
bytes_left), GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
BUG_ON(!sums); /* -ENOMEM */
sums->len = bytes_left;
ordered = btrfs_lookup_ordered_extent(inode,
offset);
ASSERT(ordered); /* Logic error */
sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
+ total_bytes;
index = 0;
}
data = kmap_atomic(bvec.bv_page);
crypto_shash_digest(shash, data + bvec.bv_offset
+ (i * fs_info->sectorsize),
fs_info->sectorsize,
sums->sums + index);
kunmap_atomic(data);
index += fs_info->csum_size;
offset += fs_info->sectorsize;
this_sum_bytes += fs_info->sectorsize;
total_bytes += fs_info->sectorsize;
}
}
this_sum_bytes = 0;
btrfs_add_ordered_sum(ordered, sums);
btrfs_put_ordered_extent(ordered);
return 0;
}
/*
* helper function for csum removal, this expects the
* key to describe the csum pointed to by the path, and it expects
* the csum to overlap the range [bytenr, len]
*
* The csum should not be entirely contained in the range and the
* range should not be entirely contained in the csum.
*
* This calls btrfs_truncate_item with the correct args based on the
* overlap, and fixes up the key as required.
*/
static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
struct btrfs_path *path,
struct btrfs_key *key,
u64 bytenr, u64 len)
{
struct extent_buffer *leaf;
const u32 csum_size = fs_info->csum_size;
u64 csum_end;
u64 end_byte = bytenr + len;
u32 blocksize_bits = fs_info->sectorsize_bits;
leaf = path->nodes[0];
csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
csum_end <<= blocksize_bits;
csum_end += key->offset;
if (key->offset < bytenr && csum_end <= end_byte) {
/*
* [ bytenr - len ]
* [ ]
* [csum ]
* A simple truncate off the end of the item
*/
u32 new_size = (bytenr - key->offset) >> blocksize_bits;
new_size *= csum_size;
btrfs_truncate_item(path, new_size, 1);
} else if (key->offset >= bytenr && csum_end > end_byte &&
end_byte > key->offset) {
/*
* [ bytenr - len ]
* [ ]
* [csum ]
* we need to truncate from the beginning of the csum
*/
u32 new_size = (csum_end - end_byte) >> blocksize_bits;
new_size *= csum_size;
btrfs_truncate_item(path, new_size, 0);
key->offset = end_byte;
btrfs_set_item_key_safe(fs_info, path, key);
} else {
BUG();
}
}
/*
* deletes the csum items from the csum tree for a given
* range of bytes.
*/
int btrfs_del_csums(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr, u64 len)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_path *path;
struct btrfs_key key;
u64 end_byte = bytenr + len;
u64 csum_end;
struct extent_buffer *leaf;
int ret;
const u32 csum_size = fs_info->csum_size;
u32 blocksize_bits = fs_info->sectorsize_bits;
ASSERT(root == fs_info->csum_root ||
root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while (1) {
key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key.offset = end_byte - 1;
key.type = BTRFS_EXTENT_CSUM_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
} else if (ret < 0) {
break;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
key.type != BTRFS_EXTENT_CSUM_KEY) {
break;
}
if (key.offset >= end_byte)
break;
csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
csum_end <<= blocksize_bits;
csum_end += key.offset;
/* this csum ends before we start, we're done */
if (csum_end <= bytenr)
break;
/* delete the entire item, it is inside our range */
if (key.offset >= bytenr && csum_end <= end_byte) {
int del_nr = 1;
/*
* Check how many csum items preceding this one in this
* leaf correspond to our range and then delete them all
* at once.
*/
if (key.offset > bytenr && path->slots[0] > 0) {
int slot = path->slots[0] - 1;
while (slot >= 0) {
struct btrfs_key pk;
btrfs_item_key_to_cpu(leaf, &pk, slot);
if (pk.offset < bytenr ||
pk.type != BTRFS_EXTENT_CSUM_KEY ||
pk.objectid !=
BTRFS_EXTENT_CSUM_OBJECTID)
break;
path->slots[0] = slot;
del_nr++;
key.offset = pk.offset;
slot--;
}
}
ret = btrfs_del_items(trans, root, path,
path->slots[0], del_nr);
if (ret)
goto out;
if (key.offset == bytenr)
break;
} else if (key.offset < bytenr && csum_end > end_byte) {
unsigned long offset;
unsigned long shift_len;
unsigned long item_offset;
/*
* [ bytenr - len ]
* [csum ]
*
* Our bytes are in the middle of the csum,
* we need to split this item and insert a new one.
*
* But we can't drop the path because the
* csum could change, get removed, extended etc.
*
* The trick here is the max size of a csum item leaves
* enough room in the tree block for a single
* item header. So, we split the item in place,
* adding a new header pointing to the existing
* bytes. Then we loop around again and we have
* a nicely formed csum item that we can neatly
* truncate.
*/
offset = (bytenr - key.offset) >> blocksize_bits;
offset *= csum_size;
shift_len = (len >> blocksize_bits) * csum_size;
item_offset = btrfs_item_ptr_offset(leaf,
path->slots[0]);
memzero_extent_buffer(leaf, item_offset + offset,
shift_len);
key.offset = bytenr;
/*
* btrfs_split_item returns -EAGAIN when the
* item changed size or key
*/
ret = btrfs_split_item(trans, root, path, &key, offset);
if (ret && ret != -EAGAIN) {
btrfs_abort_transaction(trans, ret);
goto out;
}
key.offset = end_byte - 1;
} else {
truncate_one_csum(fs_info, path, &key, bytenr, len);
if (key.offset < bytenr)
break;
}
btrfs_release_path(path);
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_ordered_sum *sums)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key file_key;
struct btrfs_key found_key;
struct btrfs_path *path;
struct btrfs_csum_item *item;
struct btrfs_csum_item *item_end;
struct extent_buffer *leaf = NULL;
u64 next_offset;
u64 total_bytes = 0;
u64 csum_offset;
u64 bytenr;
u32 nritems;
u32 ins_size;
int index = 0;
int found_next;
int ret;
const u32 csum_size = fs_info->csum_size;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
again:
next_offset = (u64)-1;
found_next = 0;
bytenr = sums->bytenr + total_bytes;
file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
file_key.offset = bytenr;
file_key.type = BTRFS_EXTENT_CSUM_KEY;
item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
if (!IS_ERR(item)) {
ret = 0;
leaf = path->nodes[0];
item_end = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_csum_item);
item_end = (struct btrfs_csum_item *)((char *)item_end +
btrfs_item_size_nr(leaf, path->slots[0]));
goto found;
}
ret = PTR_ERR(item);
if (ret != -EFBIG && ret != -ENOENT)
goto out;
if (ret == -EFBIG) {
u32 item_size;
/* we found one, but it isn't big enough yet */
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
if ((item_size / csum_size) >=
MAX_CSUM_ITEMS(fs_info, csum_size)) {
/* already at max size, make a new one */
goto insert;
}
} else {
int slot = path->slots[0] + 1;
/* we didn't find a csum item, insert one */
nritems = btrfs_header_nritems(path->nodes[0]);
if (!nritems || (path->slots[0] >= nritems - 1)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
goto out;
} else if (ret > 0) {
found_next = 1;
goto insert;
}
slot = path->slots[0];
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
found_key.type != BTRFS_EXTENT_CSUM_KEY) {
found_next = 1;
goto insert;
}
next_offset = found_key.offset;
found_next = 1;
goto insert;
}
/*
* At this point, we know the tree has a checksum item that ends at an
* offset matching the start of the checksum range we want to insert.
* We try to extend that item as much as possible and then add as many
* checksums to it as they fit.
*
* First check if the leaf has enough free space for at least one
* checksum. If it has go directly to the item extension code, otherwise
* release the path and do a search for insertion before the extension.
*/
if (btrfs_leaf_free_space(leaf) >= csum_size) {
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
csum_offset = (bytenr - found_key.offset) >>
fs_info->sectorsize_bits;
goto extend_csum;
}
btrfs_release_path(path);
ret = btrfs_search_slot(trans, root, &file_key, path,
csum_size, 1);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0)
goto insert;
path->slots[0]--;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits;
if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
goto insert;
}
extend_csum:
if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
csum_size) {
int extend_nr;
u64 tmp;
u32 diff;
tmp = sums->len - total_bytes;
tmp >>= fs_info->sectorsize_bits;
WARN_ON(tmp < 1);
extend_nr = max_t(int, 1, (int)tmp);
diff = (csum_offset + extend_nr) * csum_size;
diff = min(diff,
MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
diff /= csum_size;
diff *= csum_size;
btrfs_extend_item(path, diff);
ret = 0;
goto csum;
}
insert:
btrfs_release_path(path);
csum_offset = 0;
if (found_next) {
u64 tmp;
tmp = sums->len - total_bytes;
tmp >>= fs_info->sectorsize_bits;
tmp = min(tmp, (next_offset - file_key.offset) >>
fs_info->sectorsize_bits);
tmp = max_t(u64, 1, tmp);
tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
ins_size = csum_size * tmp;
} else {
ins_size = csum_size;
}
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
ins_size);
if (ret < 0)
goto out;
if (WARN_ON(ret != 0))
goto out;
leaf = path->nodes[0];
csum:
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
item_end = (struct btrfs_csum_item *)((unsigned char *)item +
btrfs_item_size_nr(leaf, path->slots[0]));
item = (struct btrfs_csum_item *)((unsigned char *)item +
csum_offset * csum_size);
found:
ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits;
ins_size *= csum_size;
ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
ins_size);
write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
ins_size);
index += ins_size;
ins_size /= csum_size;
total_bytes += ins_size * fs_info->sectorsize;
btrfs_mark_buffer_dirty(path->nodes[0]);
if (total_bytes < sums->len) {
btrfs_release_path(path);
cond_resched();
goto again;
}
out:
btrfs_free_path(path);
return ret;
}
void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
const struct btrfs_path *path,
struct btrfs_file_extent_item *fi,
const bool new_inline,
struct extent_map *em)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_root *root = inode->root;
struct extent_buffer *leaf = path->nodes[0];
const int slot = path->slots[0];
struct btrfs_key key;
u64 extent_start, extent_end;
u64 bytenr;
u8 type = btrfs_file_extent_type(leaf, fi);
int compress_type = btrfs_file_extent_compression(leaf, fi);
btrfs_item_key_to_cpu(leaf, &key, slot);
extent_start = key.offset;
extent_end = btrfs_file_extent_end(path);
em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
if (type == BTRFS_FILE_EXTENT_REG ||
type == BTRFS_FILE_EXTENT_PREALLOC) {
em->start = extent_start;
em->len = extent_end - extent_start;
em->orig_start = extent_start -
btrfs_file_extent_offset(leaf, fi);
em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (bytenr == 0) {
em->block_start = EXTENT_MAP_HOLE;
return;
}
if (compress_type != BTRFS_COMPRESS_NONE) {
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->compress_type = compress_type;
em->block_start = bytenr;
em->block_len = em->orig_block_len;
} else {
bytenr += btrfs_file_extent_offset(leaf, fi);
em->block_start = bytenr;
em->block_len = em->len;
if (type == BTRFS_FILE_EXTENT_PREALLOC)
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
}
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
em->block_start = EXTENT_MAP_INLINE;
em->start = extent_start;
em->len = extent_end - extent_start;
/*
* Initialize orig_start and block_len with the same values
* as in inode.c:btrfs_get_extent().
*/
em->orig_start = EXTENT_MAP_HOLE;
em->block_len = (u64)-1;
if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->compress_type = compress_type;
}
} else {
btrfs_err(fs_info,
"unknown file extent item type %d, inode %llu, offset %llu, "
"root %llu", type, btrfs_ino(inode), extent_start,
root->root_key.objectid);
}
}
/*
* Returns the end offset (non inclusive) of the file extent item the given path
* points to. If it points to an inline extent, the returned offset is rounded
* up to the sector size.
*/
u64 btrfs_file_extent_end(const struct btrfs_path *path)
{
const struct extent_buffer *leaf = path->nodes[0];
const int slot = path->slots[0];
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 end;
btrfs_item_key_to_cpu(leaf, &key, slot);
ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
end = btrfs_file_extent_ram_bytes(leaf, fi);
end = ALIGN(key.offset + end, leaf->fs_info->sectorsize);
} else {
end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
}
return end;
}