When udf_expand_file_adinicb() converts file from inline format to out of line, we use filemap_fdatawrite() to writeout the data to the new blocks. However since 36580ed08776 ("udf: Do not allocate blocks on page writeback") the writeback actually doesn't allocate the new block and the folio dirty bit is just silently cleared. Thus unless the file is written to after the conversion (as it can easily happen in case of truncate up), the data is just lost. Fix the problem by explicitely allocating the block underlying the data before starting writeback. Fixes: 36580ed08776 ("udf: Do not allocate blocks on page writeback") CC: stable@vger.kernel.org Signed-off-by: Jan Kara --- fs/udf/inode.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) I plan to merge this fix through my tree. diff --git a/fs/udf/inode.c b/fs/udf/inode.c index b8b9b7132115..b5e374f355b2 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -405,6 +405,10 @@ int udf_expand_file_adinicb(struct inode *inode) { struct folio *folio; struct udf_inode_info *iinfo = UDF_I(inode); + struct udf_map_rq map = { + .lblk = 0, + .iflags = UDF_MAP_CREATE, + }; int err; WARN_ON_ONCE(!inode_is_locked(inode)); @@ -434,20 +438,27 @@ int udf_expand_file_adinicb(struct inode *inode) iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT; else iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG; + up_write(&iinfo->i_data_sem); + + /* Allocate the block underlying the data */ + err = udf_map_block(inode, &map); + if (err < 0) + goto restore; + folio_mark_dirty(folio); folio_unlock(folio); - up_write(&iinfo->i_data_sem); err = filemap_fdatawrite(inode->i_mapping); if (err) { /* Restore everything back so that we don't lose data... */ folio_lock(folio); +restore: down_write(&iinfo->i_data_sem); memcpy_from_folio(iinfo->i_data + iinfo->i_lenEAttr, folio, 0, inode->i_size); - folio_unlock(folio); iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB; iinfo->i_lenAlloc = inode->i_size; up_write(&iinfo->i_data_sem); + folio_unlock(folio); } folio_put(folio); mark_inode_dirty(inode); -- 2.51.0