target/file: Do not return error for UNMAP if length is zero
The function fd_execute_unmap() in target_core_file.c calles
ret = file->f_op->fallocate(file, mode, pos, len);
Some filesystems implement fallocate() to return error if
length is zero (e.g. btrfs) but according to SCSI Block
Commands spec UNMAP should return success for zero length.
Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index c629817..9b2c0c77 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -482,6 +482,10 @@ fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
struct inode *inode = file->f_mapping->host;
int ret;
+ if (!nolb) {
+ return 0;
+ }
+
if (cmd->se_dev->dev_attrib.pi_prot_type) {
ret = fd_do_prot_unmap(cmd, lba, nolb);
if (ret)
