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Btrfs: Split the extent_map code into two parts

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There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.

The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller.  This allows a few performance
optimizations and is easier to use.

A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2008-01-24 16:13:08 -05:00
parent 5f56406aab
commit d1310b2e0c
14 changed files with 3614 additions and 3415 deletions
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29
fs/btrfs/file.c
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@ -233,8 +233,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
int err = 0;
int i;
struct inode *inode = fdentry(file)->d_inode;
struct extent_map *em;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
u64 hint_byte;
u64 num_bytes;
u64 start_pos;
@ -242,11 +241,6 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
u64 end_pos = pos + write_bytes;
u64 inline_size;
loff_t isize = i_size_read(inode);
em = alloc_extent_map(GFP_NOFS);
if (!em)
return -ENOMEM;
em->bdev = inode->i_sb->s_bdev;
start_pos = pos & ~((u64)root->sectorsize - 1);
num_bytes = (write_bytes + pos - start_pos +
@ -254,7 +248,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
end_of_last_block = start_pos + num_bytes - 1;
lock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS);
lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
if (!trans) {
@ -268,7 +262,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
if ((end_of_last_block & 4095) == 0) {
printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
}
set_extent_uptodate(em_tree, start_pos, end_of_last_block, GFP_NOFS);
set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS);
/* FIXME...EIEIO, ENOSPC and more */
@ -293,6 +287,8 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
inode->i_ino,
last_pos_in_file,
0, 0, hole_size);
btrfs_drop_extent_cache(inode, last_pos_in_file,
last_pos_in_file + hole_size -1);
btrfs_check_file(root, inode);
}
if (err)
@ -320,12 +316,12 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
last_end += PAGE_CACHE_SIZE - 1;
if (start_pos < isize) {
u64 delalloc_start = start_pos;
existing_delalloc = count_range_bits(em_tree,
existing_delalloc = count_range_bits(io_tree,
&delalloc_start,
end_of_last_block, (u64)-1,
EXTENT_DELALLOC);
}
set_extent_delalloc(em_tree, start_pos, end_of_last_block,
set_extent_delalloc(io_tree, start_pos, end_of_last_block,
GFP_NOFS);
spin_lock(&root->fs_info->delalloc_lock);
root->fs_info->delalloc_bytes += (end_of_last_block + 1 -
@ -346,6 +342,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
inline_size -= start_pos;
err = insert_inline_extent(trans, root, inode, start_pos,
inline_size, pages, 0, num_pages);
btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
BUG_ON(err);
}
if (end_pos > isize) {
@ -356,8 +353,7 @@ failed:
err = btrfs_end_transaction(trans, root);
out_unlock:
mutex_unlock(&root->fs_info->fs_mutex);
unlock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS);
free_extent_map(em);
unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
return err;
}
@ -367,10 +363,15 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
while(1) {
spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, end);
if (!em)
if (!em) {
spin_unlock(&em_tree->lock);
break;
}
remove_extent_mapping(em_tree, em);
spin_unlock(&em_tree->lock);
/* once for us */
free_extent_map(em);
/* once for the tree*/