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Btrfs: Add file data csums back in via hooks in the extent map code
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Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Chris Mason authored and David Woodhouse committed Aug 30, 2007
1 parent 95e0528 commit 07157aa
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Showing 3 changed files with 193 additions and 14 deletions.
94 changes: 84 additions & 10 deletions fs/btrfs/extent_map.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -57,7 +57,7 @@ void extent_map_tree_init(struct extent_map_tree *tree,
{
tree->map.rb_node = NULL;
tree->state.rb_node = NULL;
tree->fill_delalloc = NULL;
tree->ops = NULL;
rwlock_init(&tree->lock);
tree->mapping = mapping;
}
Expand Down Expand Up @@ -93,6 +93,7 @@ struct extent_state *alloc_extent_state(gfp_t mask)
return state;
state->state = 0;
state->in_tree = 0;
state->private = 0;
atomic_set(&state->refs, 1);
init_waitqueue_head(&state->wq);
return state;
Expand Down Expand Up @@ -1034,6 +1035,61 @@ int unlock_range(struct extent_map_tree *tree, u64 start, u64 end)
}
EXPORT_SYMBOL(unlock_range);

int set_state_private(struct extent_map_tree *tree, u64 start, u64 private)
{
struct rb_node *node;
struct extent_state *state;
int ret = 0;

write_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(&tree->state, start);
if (!node || IS_ERR(node)) {
ret = -ENOENT;
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
if (state->start != start) {
ret = -ENOENT;
goto out;
}
state->private = private;
out:
write_unlock_irq(&tree->lock);
return ret;

}

int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private)
{
struct rb_node *node;
struct extent_state *state;
int ret = 0;

read_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(&tree->state, start);
if (!node || IS_ERR(node)) {
ret = -ENOENT;
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
if (state->start != start) {
ret = -ENOENT;
goto out;
}
*private = state->private;
out:
read_unlock_irq(&tree->lock);
return ret;
}

/*
* searches a range in the state tree for a given mask.
* If 'filled' == 1, this returns 1 only if ever extent in the tree
Expand Down Expand Up @@ -1185,12 +1241,13 @@ static int end_bio_extent_writepage(struct bio *bio,
static int end_bio_extent_readpage(struct bio *bio,
unsigned int bytes_done, int err)
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_map_tree *tree = bio->bi_private;
u64 start;
u64 end;
int whole_page;
int ret;

if (bio->bi_size)
return 1;
Expand All @@ -1208,6 +1265,11 @@ static int end_bio_extent_readpage(struct bio *bio,
if (--bvec >= bio->bi_io_vec)
prefetchw(&bvec->bv_page->flags);

if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
ret = tree->ops->readpage_end_io_hook(page, start, end);
if (ret)
uptodate = 0;
}
if (uptodate) {
set_extent_uptodate(tree, start, end, GFP_ATOMIC);
if (whole_page)
Expand Down Expand Up @@ -1388,9 +1450,16 @@ int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
continue;
}

ret = submit_extent_page(READ, tree, page,
sector, iosize, page_offset, bdev,
end_bio_extent_readpage);
ret = 0;
if (tree->ops && tree->ops->readpage_io_hook) {
ret = tree->ops->readpage_io_hook(page, cur,
cur + iosize - 1);
}
if (!ret) {
ret = submit_extent_page(READ, tree, page,
sector, iosize, page_offset,
bdev, end_bio_extent_readpage);
}
if (ret)
SetPageError(page);
cur = cur + iosize;
Expand Down Expand Up @@ -1462,7 +1531,7 @@ int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
&delalloc_end,
128 * 1024 * 1024);
if (nr_delalloc) {
tree->fill_delalloc(inode, start, delalloc_end);
tree->ops->fill_delalloc(inode, start, delalloc_end);
if (delalloc_end >= page_end + 1) {
clear_extent_bit(tree, page_end + 1, delalloc_end,
EXTENT_LOCKED | EXTENT_DELALLOC,
Expand Down Expand Up @@ -1528,12 +1597,17 @@ int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
continue;
}
clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
set_range_writeback(tree, cur, cur + iosize - 1);
ret = submit_extent_page(WRITE, tree, page,
sector, iosize, page_offset, bdev,
end_bio_extent_writepage);
ret = tree->ops->writepage_io_hook(page, cur, cur + iosize - 1);
if (ret)
SetPageError(page);
else {
set_range_writeback(tree, cur, cur + iosize - 1);
ret = submit_extent_page(WRITE, tree, page, sector,
iosize, page_offset, bdev,
end_bio_extent_writepage);
if (ret)
SetPageError(page);
}
cur = cur + iosize;
page_offset += iosize;
nr++;
Expand Down
15 changes: 14 additions & 1 deletion fs/btrfs/extent_map.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,12 +6,19 @@
#define EXTENT_MAP_INLINE (u64)-2
#define EXTENT_MAP_DELALLOC (u64)-1

struct extent_map_ops {
int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end);
};

struct extent_map_tree {
struct rb_root map;
struct rb_root state;
struct address_space *mapping;
rwlock_t lock;
int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
struct extent_map_ops *ops;
};

/* note, this must start with the same fields as fs/extent_map.c:tree_entry */
Expand All @@ -36,6 +43,10 @@ struct extent_state {
wait_queue_head_t wq;
atomic_t refs;
unsigned long state;

/* for use by the FS */
u64 private;

struct list_head list;
};

Expand Down Expand Up @@ -89,4 +100,6 @@ int extent_commit_write(struct extent_map_tree *tree,
struct inode *inode, struct page *page,
unsigned from, unsigned to);
int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end);
int set_state_private(struct extent_map_tree *tree, u64 start, u64 private);
int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private);
#endif
98 changes: 95 additions & 3 deletions fs/btrfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -52,6 +52,7 @@ static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct address_space_operations btrfs_symlink_aops;
static struct file_operations btrfs_dir_file_operations;
static struct extent_map_ops btrfs_extent_map_ops;

static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
Expand Down Expand Up @@ -103,6 +104,90 @@ static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
return ret;
}

int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
char *kaddr;
int ret;
u64 page_start = page->index << PAGE_CACHE_SHIFT;
size_t offset = start - page_start;

mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
kaddr = kmap(page);
btrfs_csum_file_block(trans, root, inode->i_ino,
start, kaddr + offset, end - start + 1);
kunmap(page);
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}

int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
{
int ret = 0;
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct btrfs_csum_item *item;
struct btrfs_path *path = NULL;
u64 private;

mutex_lock(&root->fs_info->fs_mutex);
path = btrfs_alloc_path();
item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
if (IS_ERR(item)) {
ret = PTR_ERR(item);
/* a csum that isn't present is a preallocated region. */
if (ret == -ENOENT || ret == -EFBIG)
ret = 0;
private = 0;
goto out;
}
memcpy((char *)&private, &item->csum, BTRFS_CRC32_SIZE);
set_state_private(em_tree, start, private);
out:
if (path)
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}

int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
{
char csum[BTRFS_CRC32_SIZE];
size_t offset = start - (page->index << PAGE_CACHE_SHIFT);
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
char *kaddr;
u64 private;
int ret;

ret = get_state_private(em_tree, start, &private);
kaddr = kmap_atomic(page, KM_IRQ0);
if (ret) {
goto zeroit;
}
ret = btrfs_csum_data(root, kaddr + offset, end - start + 1, csum);
BUG_ON(ret);
if (memcmp(csum, &private, BTRFS_CRC32_SIZE)) {
goto zeroit;
}
kunmap_atomic(kaddr, KM_IRQ0);
return 0;

zeroit:
printk("btrfs csum failed ino %lu off %llu\n",
page->mapping->host->i_ino, (unsigned long long)start);
memset(kaddr + offset, 1, end - start + 1); flush_dcache_page(page);
kunmap_atomic(kaddr, KM_IRQ0);
return 0;
}

void btrfs_read_locked_inode(struct inode *inode)
{
Expand Down Expand Up @@ -155,7 +240,7 @@ void btrfs_read_locked_inode(struct inode *inode)
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->extent_tree.fill_delalloc = run_delalloc_range;
BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
Expand Down Expand Up @@ -1148,7 +1233,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
inode->i_op = &btrfs_file_inode_operations;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
inode->i_mapping, GFP_NOFS);
BTRFS_I(inode)->extent_tree.fill_delalloc = run_delalloc_range;
BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
Expand Down Expand Up @@ -2286,7 +2371,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
inode->i_op = &btrfs_file_inode_operations;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
inode->i_mapping, GFP_NOFS);
BTRFS_I(inode)->extent_tree.fill_delalloc = run_delalloc_range;
BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
Expand Down Expand Up @@ -2362,6 +2447,13 @@ static struct file_operations btrfs_dir_file_operations = {
#endif
};

static struct extent_map_ops btrfs_extent_map_ops = {
.fill_delalloc = run_delalloc_range,
.writepage_io_hook = btrfs_writepage_io_hook,
.readpage_io_hook = btrfs_readpage_io_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
};

static struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
Expand Down

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