Btrfs: early work to file_write in big extents
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index e2fc6f0..6b76fd9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1249,6 +1249,60 @@
return ret;
}
+int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, u32 data_size)
+{
+ int ret = 0;
+ int slot;
+ int slot_orig;
+ struct btrfs_leaf *leaf;
+ struct buffer_head *leaf_buf;
+ u32 nritems;
+ unsigned int data_end;
+ unsigned int old_data;
+ unsigned int old_size;
+ int i;
+
+ slot_orig = path->slots[0];
+ leaf_buf = path->nodes[0];
+ leaf = btrfs_buffer_leaf(leaf_buf);
+
+ nritems = btrfs_header_nritems(&leaf->header);
+ data_end = leaf_data_end(root, leaf);
+
+ if (btrfs_leaf_free_space(root, leaf) < data_size)
+ BUG();
+ slot = path->slots[0];
+ old_data = btrfs_item_end(leaf->items + slot);
+
+ BUG_ON(slot < 0);
+ BUG_ON(slot >= nritems);
+
+ /*
+ * item0..itemN ... dataN.offset..dataN.size .. data0.size
+ */
+ /* first correct the data pointers */
+ for (i = slot; i < nritems; i++) {
+ u32 ioff = btrfs_item_offset(leaf->items + i);
+ btrfs_set_item_offset(leaf->items + i,
+ ioff - data_size);
+ }
+ /* shift the data */
+ btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) +
+ data_end - data_size, btrfs_leaf_data(leaf) +
+ data_end, old_data - data_end);
+ data_end = old_data;
+ old_size = btrfs_item_size(leaf->items + slot);
+ btrfs_set_item_size(leaf->items + slot, old_size + data_size);
+ btrfs_mark_buffer_dirty(leaf_buf);
+
+ ret = 0;
+ if (btrfs_leaf_free_space(root, leaf) < 0)
+ BUG();
+ check_leaf(root, path, 0);
+ return ret;
+}
+
/*
* Given a key and some data, insert an item into the tree.
* This does all the path init required, making room in the tree if needed.
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index ef3583c..796f19d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -227,6 +227,7 @@
} __attribute__ ((__packed__));
struct btrfs_csum_item {
+ __le64 extent_offset;
u8 csum[BTRFS_CSUM_SIZE];
} __attribute__ ((__packed__));
@@ -924,6 +925,17 @@
e->num_blocks = cpu_to_le64(val);
}
+static inline u64 btrfs_csum_extent_offset(struct btrfs_csum_item *c)
+{
+ return le64_to_cpu(c->extent_offset);
+}
+
+static inline void btrfs_set_csum_extent_offset(struct btrfs_csum_item *c,
+ u64 val)
+{
+ c->extent_offset = cpu_to_le64(val);
+}
+
static inline u16 btrfs_device_pathlen(struct btrfs_device_item *d)
{
return le16_to_cpu(d->pathlen);
@@ -1002,6 +1014,8 @@
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
btrfs_root *root);
/* ctree.c */
+int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, u32 data_size);
int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_path *p, int
ins_len, int cow);
@@ -1071,6 +1085,7 @@
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
+ u64 extent_offset,
char *data, size_t len);
int btrfs_csum_verify_file_block(struct btrfs_root *root,
u64 objectid, u64 offset,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index d9fd7f4..93d42d6 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -3,6 +3,9 @@
#include "disk-io.h"
#include "transaction.h"
+#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+ sizeof(struct btrfs_item)) / \
+ sizeof(struct btrfs_csum_item)) - 1))
int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
@@ -43,6 +46,54 @@
return 0;
}
+static struct btrfs_csum_item *__lookup_csum_item(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset)
+{
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_csum_item *item;
+ struct btrfs_leaf *leaf;
+ u64 csum_offset = 0;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
+ if (ret < 0)
+ goto fail;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ if (ret > 0) {
+ ret = 1;
+ if (path->slots[0] == 0)
+ goto fail;
+ path->slots[0]--;
+ btrfs_disk_key_to_cpu(&found_key,
+ &leaf->items[path->slots[0]].key);
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid) {
+ goto fail;
+ }
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ if (csum_offset >=
+ btrfs_item_size(leaf->items + path->slots[0]) /
+ sizeof(struct btrfs_csum_item)) {
+ goto fail;
+ }
+ }
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item += csum_offset;
+ return item;
+fail:
+ if (ret > 0)
+ ret = -EIO;
+ return ERR_PTR(ret);
+}
+
+
int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid,
@@ -52,11 +103,16 @@
struct btrfs_key file_key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
+ struct btrfs_csum_item *csum_item;
+ csum_item = __lookup_csum_item(root, path, objectid, offset);
+ if (IS_ERR(csum_item))
+ return PTR_ERR(csum_item);
file_key.objectid = objectid;
- file_key.offset = offset;
+ file_key.offset = btrfs_csum_extent_offset(csum_item);
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+ btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
return ret;
}
@@ -64,12 +120,16 @@
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
+ u64 extent_offset,
char *data, size_t len)
{
int ret;
struct btrfs_key file_key;
+ struct btrfs_key found_key;
struct btrfs_path *path;
struct btrfs_csum_item *item;
+ struct btrfs_leaf *leaf;
+ u64 csum_offset;
path = btrfs_alloc_path();
BUG_ON(!path);
@@ -78,14 +138,50 @@
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ ret = btrfs_search_slot(trans, root, &file_key, path,
+ sizeof(struct btrfs_csum_item), 1);
+ if (ret < 0)
+ goto fail;
+ if (ret == 0) {
+ csum_offset = 0;
+ goto csum;
+ }
+ if (path->slots[0] == 0) {
+ btrfs_release_path(root, path);
+ goto insert;
+ }
+ path->slots[0]--;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid ||
+ csum_offset >= MAX_CSUM_ITEMS(root)) {
+ btrfs_release_path(root, path);
+ goto insert;
+ }
+ if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
+ sizeof(struct btrfs_csum_item)) {
+ ret = btrfs_extend_item(trans, root, path,
+ sizeof(struct btrfs_csum_item));
+ BUG_ON(ret);
+ goto csum;
+ }
+
+insert:
+ csum_offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
- BTRFS_CSUM_SIZE);
+ sizeof(struct btrfs_csum_item));
if (ret != 0 && ret != -EEXIST)
goto fail;
+csum:
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_csum_item);
ret = 0;
+ item += csum_offset;
ret = btrfs_csum_data(root, data, len, item->csum);
+ btrfs_set_csum_extent_offset(item, extent_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
fail:
btrfs_release_path(root, path);
@@ -111,12 +207,13 @@
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
mutex_lock(&root->fs_info->fs_mutex);
- ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
- if (ret)
+
+ item = __lookup_csum_item(root, path, objectid, offset);
+ if (IS_ERR(item)) {
+ ret = PTR_ERR(item);
goto fail;
- item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
- struct btrfs_csum_item);
- ret = 0;
+ }
+
ret = btrfs_csum_data(root, data, len, result);
WARN_ON(ret);
if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8dcf600..ec68999 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1027,8 +1027,10 @@
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
- if (create)
+ if (create) {
trans = btrfs_start_transaction(root, 1);
+ WARN_ON(1);
+ }
ret = btrfs_lookup_file_extent(trans, root, path,
inode->i_ino,
@@ -1055,9 +1057,8 @@
/* exact match found, use it, FIXME, deal with extents
* other than the page size
*/
- if (ret == 0) {
+ if (0 && ret == 0) {
err = 0;
- BUG_ON(btrfs_file_extent_disk_num_blocks(item) != 1);
if (create &&
btrfs_file_extent_generation(item) != trans->transid) {
struct btrfs_key ins;
@@ -1072,7 +1073,6 @@
blocknr = ins.objectid;
}
- map_bh(result, inode->i_sb, blocknr);
btrfs_map_bh_to_logical(root, result, blocknr);
goto out;
}
@@ -1231,6 +1231,7 @@
struct file *file,
struct page **pages,
size_t num_pages,
+ u64 extent_offset,
loff_t pos,
size_t write_bytes)
{
@@ -1250,6 +1251,7 @@
trans = btrfs_start_transaction(root, 1);
btrfs_csum_file_block(trans, root, inode->i_ino,
pages[i]->index << PAGE_CACHE_SHIFT,
+ extent_offset,
kmap(pages[i]), PAGE_CACHE_SIZE);
kunmap(pages[i]);
SetPageChecked(pages[i]);
@@ -1279,7 +1281,8 @@
loff_t pos,
unsigned long first_index,
unsigned long last_index,
- size_t write_bytes)
+ size_t write_bytes,
+ u64 alloc_extent_start)
{
int i;
unsigned long index = pos >> PAGE_CACHE_SHIFT;
@@ -1288,6 +1291,8 @@
int err = 0;
int ret;
int this_write;
+ struct buffer_head *bh;
+ struct buffer_head *head;
loff_t isize = i_size_read(inode);
memset(pages, 0, num_pages * sizeof(struct page *));
@@ -1307,14 +1312,20 @@
BUG_ON(ret);
lock_page(pages[i]);
}
- ret = nobh_prepare_write(pages[i], offset,
- offset + this_write,
- btrfs_get_block);
+ create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize,
+ (1 << BH_Uptodate));
+ head = page_buffers(pages[i]);
+ bh = head;
+ do {
+ err = btrfs_map_bh_to_logical(root, bh,
+ alloc_extent_start);
+ BUG_ON(err);
+ if (err)
+ goto failed_truncate;
+ bh = bh->b_this_page;
+ alloc_extent_start++;
+ } while (bh != head);
pos += this_write;
- if (ret) {
- err = ret;
- goto failed_truncate;
- }
WARN_ON(this_write > write_bytes);
write_bytes -= this_write;
}
@@ -1343,11 +1354,23 @@
struct page *pages[1];
unsigned long first_index;
unsigned long last_index;
+ u64 start_pos;
+ u64 num_blocks;
+ u64 alloc_extent_start;
+ u64 orig_extent_start;
+ struct btrfs_trans_handle *trans;
if (file->f_flags & O_DIRECT)
return -EINVAL;
pos = *ppos;
+ start_pos = pos & ~(root->blocksize - 1);
+ /* FIXME */
+ if (start_pos != pos)
+ return -EINVAL;
+ num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
+ inode->i_blkbits;
+
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
current->backing_dev_info = inode->i_mapping->backing_dev_info;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@@ -1362,20 +1385,41 @@
mutex_lock(&inode->i_mutex);
first_index = pos >> PAGE_CACHE_SHIFT;
last_index = (pos + count) >> PAGE_CACHE_SHIFT;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ if (!trans) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+ ret = btrfs_alloc_file_extent(trans, root, inode->i_ino,
+ start_pos, num_blocks, 1,
+ &alloc_extent_start);
+ BUG_ON(ret);
+
+ orig_extent_start = start_pos;
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->fs_mutex);
+
while(count > 0) {
size_t offset = pos & (PAGE_CACHE_SIZE - 1);
size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
ret = prepare_pages(NULL, root, file, pages, num_pages,
- pos, first_index, last_index, write_bytes);
+ pos, first_index, last_index,
+ write_bytes, alloc_extent_start);
BUG_ON(ret);
+ /* FIXME blocks != pagesize */
+ alloc_extent_start += num_pages;
ret = btrfs_copy_from_user(pos, num_pages,
write_bytes, pages, buf);
BUG_ON(ret);
ret = dirty_and_release_pages(NULL, root, file, pages,
- num_pages, pos, write_bytes);
+ num_pages, orig_extent_start,
+ pos, write_bytes);
BUG_ON(ret);
btrfs_drop_pages(pages, num_pages);
@@ -1387,6 +1431,7 @@
balance_dirty_pages_ratelimited(inode->i_mapping);
cond_resched();
}
+out_unlock:
mutex_unlock(&inode->i_mutex);
out:
*ppos = pos;
@@ -1806,8 +1851,6 @@
&new_root_item);
BUG_ON(ret);
-printk("adding snapshot name %.*s root %Lu %Lu %u\n", namelen, name, key.objectid, key.offset, key.flags);
-
/*
* insert the directory item
*/