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authorRichard Weinberger <richard@nod.at>2013-08-18 15:30:06 +0400
committerRichard Weinberger <richard@nod.at>2013-09-07 12:56:49 +0400
commit805f11a0d515658106bfbfadceff0eb30bd90ad2 (patch)
tree2bcfbc9028d5a92875272302bd9e7daf82b4e4be /arch/um/os-Linux
parentf75b1b1bedfb498cc43a992ce4d7ed8df3b1e770 (diff)
downloadlinux-805f11a0d515658106bfbfadceff0eb30bd90ad2.tar.xz
um: ubd: Add REQ_FLUSH suppport
UML's block device driver does not support write barriers, to support this this patch adds REQ_FLUSH suppport. Every time the block layer sends a REQ_FLUSH we fsync() now our backing file to guarantee data consistency. Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/os-Linux')
-rw-r--r--arch/um/os-Linux/file.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index c17bd6f7d674..07a750197bb0 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -266,6 +266,15 @@ int os_write_file(int fd, const void *buf, int len)
return n;
}
+int os_sync_file(int fd)
+{
+ int n = fsync(fd);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
int os_file_size(const char *file, unsigned long long *size_out)
{
struct uml_stat buf;