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Btrfs: Fix disk_i_size update corner case
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There are some cases file extents are inserted without involving
ordered struct. In these cases, we update disk_i_size directly,
without checking pending ordered extent and DELALLOC bit. This
patch extends btrfs_ordered_update_i_size() to handle these cases.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Yan, Zheng authored and Chris Mason committed Dec 17, 2009
1 parent 920bbbf commit c216775
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Showing 4 changed files with 127 additions and 56 deletions.
5 changes: 1 addition & 4 deletions fs/btrfs/btrfs_inode.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -44,9 +44,6 @@ struct btrfs_inode {
*/
struct extent_io_tree io_failure_tree;

/* held while inesrting or deleting extents from files */
struct mutex extent_mutex;

/* held while logging the inode in tree-log.c */
struct mutex log_mutex;

Expand Down Expand Up @@ -166,7 +163,7 @@ static inline struct btrfs_inode *BTRFS_I(struct inode *inode)

static inline void btrfs_i_size_write(struct inode *inode, u64 size)
{
inode->i_size = size;
i_size_write(inode, size);
BTRFS_I(inode)->disk_i_size = size;
}

Expand Down
71 changes: 44 additions & 27 deletions fs/btrfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -188,8 +188,18 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);

/*
* we're an inline extent, so nobody can
* extend the file past i_size without locking
* a page we already have locked.
*
* We must do any isize and inode updates
* before we unlock the pages. Otherwise we
* could end up racing with unlink.
*/
BTRFS_I(inode)->disk_i_size = inode->i_size;
btrfs_update_inode(trans, root, inode);

return 0;
fail:
btrfs_free_path(path);
Expand Down Expand Up @@ -415,7 +425,6 @@ static noinline int compress_file_range(struct inode *inode,
start, end,
total_compressed, pages);
}
btrfs_end_transaction(trans, root);
if (ret == 0) {
/*
* inline extent creation worked, we don't need
Expand All @@ -429,9 +438,11 @@ static noinline int compress_file_range(struct inode *inode,
EXTENT_CLEAR_DELALLOC |
EXTENT_CLEAR_ACCOUNTING |
EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
ret = 0;

btrfs_end_transaction(trans, root);
goto free_pages_out;
}
btrfs_end_transaction(trans, root);
}

if (will_compress) {
Expand Down Expand Up @@ -542,7 +553,6 @@ static noinline int submit_compressed_extents(struct inode *inode,
if (list_empty(&async_cow->extents))
return 0;

trans = btrfs_join_transaction(root, 1);

while (!list_empty(&async_cow->extents)) {
async_extent = list_entry(async_cow->extents.next,
Expand Down Expand Up @@ -589,19 +599,15 @@ static noinline int submit_compressed_extents(struct inode *inode,
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1,
GFP_NOFS);
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);

trans = btrfs_join_transaction(root, 1);
ret = btrfs_reserve_extent(trans, root,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint,
(u64)-1, &ins, 1);
btrfs_end_transaction(trans, root);

if (ret) {
int i;
for (i = 0; i < async_extent->nr_pages; i++) {
Expand All @@ -617,6 +623,14 @@ static noinline int submit_compressed_extents(struct inode *inode,
goto retry;
}

/*
* here we're doing allocation and writeback of the
* compressed pages
*/
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);

em = alloc_extent_map(GFP_NOFS);
em->start = async_extent->start;
em->len = async_extent->ram_size;
Expand Down Expand Up @@ -648,8 +662,6 @@ static noinline int submit_compressed_extents(struct inode *inode,
BTRFS_ORDERED_COMPRESSED);
BUG_ON(ret);

btrfs_end_transaction(trans, root);

/*
* clear dirty, set writeback and unlock the pages.
*/
Expand All @@ -671,13 +683,11 @@ static noinline int submit_compressed_extents(struct inode *inode,
async_extent->nr_pages);

BUG_ON(ret);
trans = btrfs_join_transaction(root, 1);
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}

btrfs_end_transaction(trans, root);
return 0;
}

Expand Down Expand Up @@ -741,6 +751,7 @@ static noinline int cow_file_range(struct inode *inode,
EXTENT_CLEAR_DIRTY |
EXTENT_SET_WRITEBACK |
EXTENT_END_WRITEBACK);

*nr_written = *nr_written +
(end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
*page_started = 1;
Expand Down Expand Up @@ -1727,18 +1738,27 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
}
}

trans = btrfs_join_transaction(root, 1);

if (!ordered_extent)
ordered_extent = btrfs_lookup_ordered_extent(inode, start);
BUG_ON(!ordered_extent);
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
goto nocow;
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list));
ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (!ret) {
trans = btrfs_join_transaction(root, 1);
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
btrfs_end_transaction(trans, root);
}
goto out;
}

lock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
GFP_NOFS);

trans = btrfs_join_transaction(root, 1);

if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compressed = 1;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
Expand All @@ -1765,22 +1785,20 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
unlock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
GFP_NOFS);
nocow:
add_pending_csums(trans, inode, ordered_extent->file_offset,
&ordered_extent->list);

mutex_lock(&BTRFS_I(inode)->extent_mutex);
btrfs_ordered_update_i_size(inode, ordered_extent);
btrfs_update_inode(trans, root, inode);
btrfs_remove_ordered_extent(inode, ordered_extent);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);

/* this also removes the ordered extent from the tree */
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
btrfs_end_transaction(trans, root);
out:
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);

btrfs_end_transaction(trans, root);
return 0;
}

Expand Down Expand Up @@ -3562,7 +3580,6 @@ static noinline void init_btrfs_i(struct inode *inode)
INIT_LIST_HEAD(&BTRFS_I(inode)->ordered_operations);
RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
mutex_init(&BTRFS_I(inode)->extent_mutex);
mutex_init(&BTRFS_I(inode)->log_mutex);
}

Expand Down
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