From ee6e6504e147a59a9f4d582662c105e9d72ae638 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 17 Jul 2008 12:54:40 -0400 Subject: 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 --- fs/btrfs/file.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs/btrfs/file.c') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 3e4e5c227c0..40ad1b2958c 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -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: -- cgit v1.2.3