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Btrfs: early work to file_write in big extents

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2007-04-16 09:22:45 -04:00
committed by David Woodhouse
parent b4100d6424
commit 6567e837df
4 changed files with 232 additions and 23 deletions
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75
fs/btrfs/super.c
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@ -1027,8 +1027,10 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
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 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
/* 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 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
blocknr = ins.objectid;
}
map_bh(result, inode->i_sb, blocknr);
btrfs_map_bh_to_logical(root, result, blocknr);
goto out;
}
@ -1231,6 +1231,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
struct file *file,
struct page **pages,
size_t num_pages,
u64 extent_offset,
loff_t pos,
size_t write_bytes)
{
@ -1250,6 +1251,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
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 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
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 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
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 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
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 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
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 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
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 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
balance_dirty_pages_ratelimited(inode->i_mapping);
cond_resched();
}
out_unlock:
mutex_unlock(&inode->i_mutex);
out:
*ppos = pos;
@ -1806,8 +1851,6 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
&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
*/