diff options
| -rw-r--r-- | fs/btrfs/inode.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e5284f2686c8..c479e5f16f74 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8252,6 +8252,26 @@ static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, if (ret) return ret; + /* + * fiemap_prep() called filemap_write_and_wait() for the whole possible + * file range (0 to LLONG_MAX), but that is not enough if we have + * compression enabled. The first filemap_fdatawrite_range() only kicks + * in the compression of data (in an async thread) and will return + * before the compression is done and writeback is started. A second + * filemap_fdatawrite_range() is needed to wait for the compression to + * complete and writeback to start. Without this, our user is very + * likely to get stale results, because the extents and extent maps for + * delalloc regions are only allocated when writeback starts. + */ + if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC) { + ret = btrfs_fdatawrite_range(inode, 0, LLONG_MAX); + if (ret) + return ret; + ret = filemap_fdatawait_range(inode->i_mapping, 0, LLONG_MAX); + if (ret) + return ret; + } + return extent_fiemap(BTRFS_I(inode), fieinfo, start, len); } |