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Commit 0414efae authored by Li Zefan's avatar Li Zefan
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Btrfs: Make the code for reading/writing free space cache generic 

Extract out block group specific code from lookup_free_space_inode(),
create_free_space_inode(), load_free_space_cache() and
btrfs_write_out_cache(), so the code can be used to read/write
free ino cache.
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent 581bb050
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Inline Side-by-side
Showing with 204 additions and 154 deletions
fs/btrfs/free-space-cache.c
View file @ 0414efae
......@@ -33,9 +33,9 @@
static int link_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info);
struct inode *lookup_free_space_inode(struct btrfs_root *root,
struct btrfs_block_group_cache
*block_group, struct btrfs_path *path)
static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
struct btrfs_path *path,
u64 offset)
{
struct btrfs_key key;
struct btrfs_key location;
......@@ -45,15 +45,8 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root,
struct inode *inode = NULL;
int ret;
spin_lock(&block_group->lock);
if (block_group->inode)
inode = igrab(block_group->inode);
spin_unlock(&block_group->lock);
if (inode)
return inode;
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.offset = offset;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
......@@ -83,6 +76,27 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root,
inode->i_mapping->flags &= ~__GFP_FS;
return inode;
}
struct inode *lookup_free_space_inode(struct btrfs_root *root,
struct btrfs_block_group_cache
*block_group, struct btrfs_path *path)
{
struct inode *inode = NULL;
spin_lock(&block_group->lock);
if (block_group->inode)
inode = igrab(block_group->inode);
spin_unlock(&block_group->lock);
if (inode)
return inode;
inode = __lookup_free_space_inode(root, path,
block_group->key.objectid);
if (IS_ERR(inode))
return inode;
spin_lock(&block_group->lock);
if (!root->fs_info->closing) {
block_group->inode = igrab(inode);
......@@ -93,24 +107,18 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root,
return inode;
}
int create_free_space_inode(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
int __create_free_space_inode(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_path *path, u64 ino, u64 offset)
{
struct btrfs_key key;
struct btrfs_disk_key disk_key;
struct btrfs_free_space_header *header;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
u64 objectid;
int ret;
ret = btrfs_find_free_objectid(root, &objectid);
if (ret < 0)
return ret;
ret = btrfs_insert_empty_inode(trans, root, path, objectid);
ret = btrfs_insert_empty_inode(trans, root, path, ino);
if (ret)
return ret;
......@@ -130,13 +138,12 @@ int create_free_space_inode(struct btrfs_root *root,
BTRFS_INODE_PREALLOC | BTRFS_INODE_NODATASUM);
btrfs_set_inode_nlink(leaf, inode_item, 1);
btrfs_set_inode_transid(leaf, inode_item, trans->transid);
btrfs_set_inode_block_group(leaf, inode_item,
block_group->key.objectid);
btrfs_set_inode_block_group(leaf, inode_item, offset);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(root, path);
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.offset = offset;
key.type = 0;
ret = btrfs_insert_empty_item(trans, root, path, &key,
......@@ -156,6 +163,22 @@ int create_free_space_inode(struct btrfs_root *root,
return 0;
}
int create_free_space_inode(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
int ret;
u64 ino;
ret = btrfs_find_free_objectid(root, &ino);
if (ret < 0)
return ret;
return __create_free_space_inode(root, trans, path, ino,
block_group->key.objectid);
}
int btrfs_truncate_free_space_cache(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_path *path,
......@@ -208,16 +231,13 @@ static int readahead_cache(struct inode *inode)
return 0;
}
int load_free_space_cache(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group)
int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
struct btrfs_free_space_ctl *ctl,
struct btrfs_path *path, u64 offset)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_root *root = fs_info->tree_root;
struct inode *inode;
struct btrfs_free_space_header *header;
struct extent_buffer *leaf;
struct page *page;
struct btrfs_path *path;
u32 *checksums = NULL, *crc;
char *disk_crcs = NULL;
struct btrfs_key key;
......@@ -225,76 +245,47 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
u64 num_entries;
u64 num_bitmaps;
u64 generation;
u64 used = btrfs_block_group_used(&block_group->item);
u32 cur_crc = ~(u32)0;
pgoff_t index = 0;
unsigned long first_page_offset;
int num_checksums;
int ret = 0;
/*
* If we're unmounting then just return, since this does a search on the
* normal root and not the commit root and we could deadlock.
*/
smp_mb();
if (fs_info->closing)
return 0;
/*
* If this block group has been marked to be cleared for one reason or
* another then we can't trust the on disk cache, so just return.
*/
spin_lock(&block_group->lock);
if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
spin_unlock(&block_group->lock);
return 0;
}
spin_unlock(&block_group->lock);
int ret = 0, ret2;
INIT_LIST_HEAD(&bitmaps);
path = btrfs_alloc_path();
if (!path)
return 0;
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode)) {
btrfs_free_path(path);
return 0;
}
/* Nothing in the space cache, goodbye */
if (!i_size_read(inode)) {
btrfs_free_path(path);
if (!i_size_read(inode))
goto out;
}
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.offset = offset;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret) {
btrfs_free_path(path);
if (ret < 0)
goto out;
else if (ret > 0) {
btrfs_release_path(root, path);
ret = 0;
goto out;
}
ret = -1;
leaf = path->nodes[0];
header = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_free_space_header);
num_entries = btrfs_free_space_entries(leaf, header);
num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
generation = btrfs_free_space_generation(leaf, header);
btrfs_free_path(path);
btrfs_release_path(root, path);
if (BTRFS_I(inode)->generation != generation) {
printk(KERN_ERR "btrfs: free space inode generation (%llu) did"
" not match free space cache generation (%llu) for "
"block group %llu\n",
" not match free space cache generation (%llu)\n",
(unsigned long long)BTRFS_I(inode)->generation,
(unsigned long long)generation,
(unsigned long long)block_group->key.objectid);
goto free_cache;
(unsigned long long)generation);
goto out;
}
if (!num_entries)
......@@ -311,10 +302,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
goto out;
ret = readahead_cache(inode);
if (ret) {
ret = 0;
if (ret)
goto out;
}
while (1) {
struct btrfs_free_space_entry *entry;
......@@ -333,10 +322,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
}
page = grab_cache_page(inode->i_mapping, index);
if (!page) {
ret = 0;
if (!page)
goto free_cache;
}
if (!PageUptodate(page)) {
btrfs_readpage(NULL, page);
......@@ -345,9 +332,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
unlock_page(page);
page_cache_release(page);
printk(KERN_ERR "btrfs: error reading free "
"space cache: %llu\n",
(unsigned long long)
block_group->key.objectid);
"space cache\n");
goto free_cache;
}
}
......@@ -360,13 +345,10 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
gen = addr + (sizeof(u32) * num_checksums);
if (*gen != BTRFS_I(inode)->generation) {
printk(KERN_ERR "btrfs: space cache generation"
" (%llu) does not match inode (%llu) "
"for block group %llu\n",
" (%llu) does not match inode (%llu)\n",
(unsigned long long)*gen,
(unsigned long long)
BTRFS_I(inode)->generation,
(unsigned long long)
block_group->key.objectid);
BTRFS_I(inode)->generation);
kunmap(page);
unlock_page(page);
page_cache_release(page);
......@@ -382,9 +364,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
PAGE_CACHE_SIZE - start_offset);
btrfs_csum_final(cur_crc, (char *)&cur_crc);
if (cur_crc != *crc) {
printk(KERN_ERR "btrfs: crc mismatch for page %lu in "
"block group %llu\n", index,
(unsigned long long)block_group->key.objectid);
printk(KERN_ERR "btrfs: crc mismatch for page %lu\n",
index);
kunmap(page);
unlock_page(page);
page_cache_release(page);
......@@ -432,7 +413,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
goto free_cache;
}
spin_lock(&ctl->tree_lock);
ret = link_free_space(ctl, e);
ret2 = link_free_space(ctl, e);
ctl->total_bitmaps++;
ctl->op->recalc_thresholds(ctl);
spin_unlock(&ctl->tree_lock);
......@@ -471,42 +452,96 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
index++;
}
spin_lock(&ctl->tree_lock);
if (ctl->free_space != (block_group->key.offset - used -
block_group->bytes_super)) {
spin_unlock(&ctl->tree_lock);
printk(KERN_ERR "block group %llu has an wrong amount of free "
"space\n", block_group->key.objectid);
ret = 0;
goto free_cache;
}
spin_unlock(&ctl->tree_lock);
ret = 1;
out:
kfree(checksums);
kfree(disk_crcs);
iput(inode);
return ret;
free_cache:
/* This cache is bogus, make sure it gets cleared */
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_CLEAR;
spin_unlock(&block_group->lock);
btrfs_remove_free_space_cache(block_group);
__btrfs_remove_free_space_cache(ctl);
goto out;
}
int btrfs_write_out_cache(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
int load_free_space_cache(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_root *root = fs_info->tree_root;
struct inode *inode;
struct btrfs_path *path;
int ret;
bool matched;
u64 used = btrfs_block_group_used(&block_group->item);
/*
* If we're unmounting then just return, since this does a search on the
* normal root and not the commit root and we could deadlock.
*/
smp_mb();
if (fs_info->closing)
return 0;
/*
* If this block group has been marked to be cleared for one reason or
* another then we can't trust the on disk cache, so just return.
*/
spin_lock(&block_group->lock);
if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
spin_unlock(&block_group->lock);
return 0;
}
spin_unlock(&block_group->lock);
path = btrfs_alloc_path();
if (!path)
return 0;
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode)) {
btrfs_free_path(path);
return 0;
}
ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
path, block_group->key.objectid);
btrfs_free_path(path);
if (ret <= 0)
goto out;
spin_lock(&ctl->tree_lock);
matched = (ctl->free_space == (block_group->key.offset - used -
block_group->bytes_super));
spin_unlock(&ctl->tree_lock);
if (!matched) {
__btrfs_remove_free_space_cache(ctl);
printk(KERN_ERR "block group %llu has an wrong amount of free "
"space\n", block_group->key.objectid);
ret = -1;
}
out:
if (ret < 0) {
/* This cache is bogus, make sure it gets cleared */
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_CLEAR;
spin_unlock(&block_group->lock);
printk(KERN_ERR "btrfs: failed to load free space cache "
"for block group %llu\n", block_group->key.objectid);
}
iput(inode);
return ret;
}
int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
struct btrfs_free_space_ctl *ctl,
struct btrfs_block_group_cache *block_group,
struct btrfs_trans_handle *trans,
struct btrfs_path *path, u64 offset)
{
struct btrfs_free_space_header *header;
struct extent_buffer *leaf;
struct inode *inode;
struct rb_node *node;
struct list_head *pos, *n;
struct page **pages;
......@@ -523,35 +558,18 @@ int btrfs_write_out_cache(struct btrfs_root *root,
int index = 0, num_pages = 0;
int entries = 0;
int bitmaps = 0;
int ret = 0;
int ret = -1;
bool next_page = false;
bool out_of_space = false;
root = root->fs_info->tree_root;
INIT_LIST_HEAD(&bitmap_list);
spin_lock(&block_group->lock);
if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
spin_unlock(&block_group->lock);
return 0;
}
spin_unlock(&block_group->lock);
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode))
return 0;
if (!i_size_read(inode)) {
iput(inode);
return 0;
}
node = rb_first(&ctl->free_space_offset);
if (!node) {
iput(inode);
if (!node)
return 0;
}
if (!i_size_read(inode))
return -1;
num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
......@@ -561,16 +579,13 @@ int btrfs_write_out_cache(struct btrfs_root *root,
/* We need a checksum per page. */
crc = checksums = kzalloc(sizeof(u32) * num_pages, GFP_NOFS);
if (!crc) {
iput(inode);
return 0;
}
if (!crc)
return -1;
pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
if (!pages) {
kfree(crc);
iput(inode);
return 0;
return -1;
}
/* Since the first page has all of our checksums and our generation we
......@@ -580,7 +595,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
first_page_offset = (sizeof(u32) * num_pages) + sizeof(u64);
/* Get the cluster for this block_group if it exists */
if (!list_empty(&block_group->cluster_list))
if (block_group && !list_empty(&block_group->cluster_list))
cluster = list_entry(block_group->cluster_list.next,
struct btrfs_free_cluster,
block_group_list);
......@@ -622,7 +637,8 @@ int btrfs_write_out_cache(struct btrfs_root *root,
* When searching for pinned extents, we need to start at our start
* offset.
*/
start = block_group->key.objectid;
if (block_group)
start = block_group->key.objectid;
/* Write out the extent entries */
do {
......@@ -680,8 +696,9 @@ int btrfs_write_out_cache(struct btrfs_root *root,
* We want to add any pinned extents to our free space cache
* so we don't leak the space
*/
while (!next_page && (start < block_group->key.objectid +
block_group->key.offset)) {
while (block_group && !next_page &&
(start < block_group->key.objectid +
block_group->key.offset)) {
ret = find_first_extent_bit(unpin, start, &start, &end,
EXTENT_DIRTY);
if (ret) {
......@@ -799,12 +816,12 @@ int btrfs_write_out_cache(struct btrfs_root *root,
filemap_write_and_wait(inode->i_mapping);
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.offset = offset;
key.type = 0;
ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
if (ret < 0) {
ret = 0;
ret = -1;
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS);
......@@ -817,8 +834,8 @@ int btrfs_write_out_cache(struct btrfs_root *root,
path->slots[0]--;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
found_key.offset != block_group->key.objectid) {
ret = 0;
found_key.offset != offset) {
ret = -1;
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING, 0, 0, NULL,
......@@ -838,16 +855,49 @@ int btrfs_write_out_cache(struct btrfs_root *root,
ret = 1;
out_free:
if (ret == 0) {
if (ret != 1) {
invalidate_inode_pages2_range(inode->i_mapping, 0, index);
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_ERROR;
spin_unlock(&block_group->lock);
BTRFS_I(inode)->generation = 0;
}
kfree(checksums);
kfree(pages);
btrfs_update_inode(trans, root, inode);
return ret;
}
int btrfs_write_out_cache(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct inode *inode;
int ret = 0;
root = root->fs_info->tree_root;
spin_lock(&block_group->lock);
if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
spin_unlock(&block_group->lock);
return 0;
}
spin_unlock(&block_group->lock);
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode))
return 0;
ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
path, block_group->key.objectid);
if (ret < 0) {
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_ERROR;
spin_unlock(&block_group->lock);
printk(KERN_ERR "btrfs: failed to write free space cace "
"for block group %llu\n", block_group->key.objectid);
}
iput(inode);
return ret;
}
......
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