staging: android: ashmem: lseek failed due to no FMODE_LSEEK.

vfs_llseek will check whether the file mode has
FMODE_LSEEK, no return failure. But ashmem can be
lseek, so add FMODE_LSEEK to ashmem file.

Comment From Greg Hackmann:
	ashmem_llseek() passes the llseek() call through to the backing
	shmem file.  91360b02ab48 ("ashmem: use vfs_llseek()") changed
	this from directly calling the file's llseek() op into a VFS
	layer call.  This also adds a check for the FMODE_LSEEK bit, so
	without that bit ashmem_llseek() now always fails with -ESPIPE.

Fixes: 91360b02ab48 ("ashmem: use vfs_llseek()")
Signed-off-by: Shuxiao Zhang <>
Tested-by: Greg Hackmann <>
Cc: stable <> # 3.18+
Signed-off-by: Greg Kroah-Hartman <>
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 7cbad0d..6ba270e 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -409,6 +409,7 @@
 			ret = PTR_ERR(vmfile);
 			goto out;
+		vmfile->f_mode |= FMODE_LSEEK;
 		asma->file = vmfile;