3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiang Yi <jiangyilism@xxxxxxxxx>
[ Upstream commit 594e25e73440863981032d76c9b1e33409ceff6e ]
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@xxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_file.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -592,6 +592,10 @@ fd_do_unmap(struct se_cmd *cmd, void *pr
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)