On Fri 13-06-25 11:18:38, Wei Gao wrote: > Previously, ext2_fiemap would unconditionally apply "len = min_t(u64, len, > i_size_read(inode));", When inode->i_size was 0 (for an empty file), this > would reduce the requested len to 0. Passing len = 0 to iomap_fiemap could > then result in an -EINVAL error, even for valid queries on empty files. > > Link: https://github.com/linux-test-project/ltp/issues/1246 > Signed-off-by: Wei Gao <wegao@xxxxxxxx> ... > diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c > index 30f8201c155f..591db2b4390a 100644 > --- a/fs/ext2/inode.c > +++ b/fs/ext2/inode.c > @@ -895,9 +895,15 @@ int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > u64 start, u64 len) > { > int ret; > + u64 i_size; > > inode_lock(inode); > - len = min_t(u64, len, i_size_read(inode)); > + > + i_size = i_size_read(inode); > + > + if (i_size > 0) > + len = min_t(u64, len, i_size_read(inode)); Thanks! This would actually lead to excessively slow fiemap for 0-length files. So what I've ended up with is attached modification of your patch. > + > ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops); > inode_unlock(inode); > > -- > 2.49.0 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR ---
