Add a per-inode lock around btrfs_drop_extents

btrfs_drop_extents is always called with a range lock held on the inode.
But, it may operate on extents outside that range as it drops and splits
them.

This patch adds a per-inode mutex that is held while calling
btrfs_drop_extents and while inserting new extents into the tree.  It
prevents races from two procs working against adjacent ranges in the tree.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2008-07-17 12:54:40 -04:00
parent ba1da2f442
commit ee6e6504e1
4 changed files with 21 additions and 0 deletions

View File

@ -32,6 +32,7 @@ struct btrfs_inode {
struct extent_io_tree io_tree;
struct extent_io_tree io_failure_tree;
struct mutex csum_mutex;
struct mutex extent_mutex;
struct inode vfs_inode;
struct btrfs_ordered_inode_tree ordered_tree;

View File

@ -1671,6 +1671,8 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
ref_generation, owner_objectid, owner_offset,
pin, pin == 0);
finish_current_insert(trans, root->fs_info->extent_root);
pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
return ret ? ret : pending_ret;
}

View File

@ -242,6 +242,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
u64 end_of_last_block;
u64 end_pos = pos + write_bytes;
u64 inline_size;
int did_inline = 0;
loff_t isize = i_size_read(inode);
start_pos = pos & ~((u64)root->sectorsize - 1);
@ -275,6 +276,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
if (hole_size > 0) {
btrfs_wait_ordered_range(inode, last_pos_in_file,
last_pos_in_file + hole_size);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
err = btrfs_drop_extents(trans, root, inode,
last_pos_in_file,
last_pos_in_file + hole_size,
@ -289,6 +291,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
0, 0, hole_size, 0);
btrfs_drop_extent_cache(inode, last_pos_in_file,
last_pos_in_file + hole_size -1);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
btrfs_check_file(root, inode);
}
if (err)
@ -321,6 +324,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
/* step one, delete the existing extents in this range */
aligned_end = (pos + write_bytes + root->sectorsize - 1) &
~((u64)root->sectorsize - 1);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
err = btrfs_drop_extents(trans, root, inode, start_pos,
aligned_end, aligned_end, &hint_byte);
if (err)
@ -332,9 +336,13 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
inline_size, pages, 0, num_pages);
btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
BUG_ON(err);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
did_inline = 1;
}
if (end_pos > isize) {
i_size_write(inode, end_pos);
if (did_inline)
BTRFS_I(inode)->disk_i_size = end_pos;
btrfs_update_inode(trans, root, inode);
}
failed:

View File

@ -516,6 +516,8 @@ int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
trans->transid, inode->i_ino,
ordered_extent->file_offset, &ins);
BUG_ON(ret);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
ret = btrfs_drop_extents(trans, root, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
@ -531,6 +533,8 @@ int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
btrfs_drop_extent_cache(inode, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
inode->i_blocks += ordered_extent->len >> 9;
unlock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
@ -1399,6 +1403,7 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
mutex_lock(&BTRFS_I(inode)->extent_mutex);
err = btrfs_drop_extents(trans, root, inode,
hole_start, block_end, hole_start,
&alloc_hint);
@ -1412,6 +1417,7 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
(u64)-1);
btrfs_check_file(root, inode);
}
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
btrfs_end_transaction(trans, root);
unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
if (err)
@ -1578,6 +1584,7 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p)
inode->i_mapping, GFP_NOFS);
btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
mutex_init(&BTRFS_I(inode)->csum_mutex);
mutex_init(&BTRFS_I(inode)->extent_mutex);
return 0;
}
@ -1880,6 +1887,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
inode->i_mapping, GFP_NOFS);
btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
mutex_init(&BTRFS_I(inode)->csum_mutex);
mutex_init(&BTRFS_I(inode)->extent_mutex);
BTRFS_I(inode)->delalloc_bytes = 0;
BTRFS_I(inode)->disk_i_size = 0;
BTRFS_I(inode)->root = root;
@ -2105,6 +2113,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
inode->i_mapping, GFP_NOFS);
mutex_init(&BTRFS_I(inode)->csum_mutex);
mutex_init(&BTRFS_I(inode)->extent_mutex);
BTRFS_I(inode)->delalloc_bytes = 0;
BTRFS_I(inode)->disk_i_size = 0;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
@ -3079,6 +3088,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
inode->i_mapping, GFP_NOFS);
mutex_init(&BTRFS_I(inode)->csum_mutex);
mutex_init(&BTRFS_I(inode)->extent_mutex);
BTRFS_I(inode)->delalloc_bytes = 0;
BTRFS_I(inode)->disk_i_size = 0;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;