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> Signed-off-by: Jan Kara <jack@xxxxxxx> Link: https://patch.msgid.link/20250613152402.3432135-1-wegao@xxxxxxxx --- fs/ext2/inode.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 30f8201c155f..177b1f852b63 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -895,9 +895,19 @@ int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { int ret; + loff_t i_size; inode_lock(inode); - len = min_t(u64, len, i_size_read(inode)); + i_size = i_size_read(inode); + /* + * iomap_fiemap() returns EINVAL for 0 length. Make sure we don't trim + * length to 0 but still trim the range as much as possible since + * ext2_get_blocks() iterates unmapped space block by block which is + * slow. + */ + if (i_size == 0) + i_size = 1; + len = min_t(u64, len, i_size); ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops); inode_unlock(inode); -- 2.43.0
