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authorAnton Ivanov <aivanov@brocade.com>2015-12-21 21:54:00 +0300
committerRichard Weinberger <richard@nod.at>2016-01-10 23:49:48 +0300
commit8c6157b6b30a765ec233a1be5f9446f24a5283de (patch)
tree81128a9f0252bd4075b6093cf5408eab19d45ce4 /arch/um/os-Linux/file.c
parent470a166e8c5a4da4be88545b1c4dde308abac5b2 (diff)
downloadlinux-8c6157b6b30a765ec233a1be5f9446f24a5283de.tar.xz
um: Update UBD to use pread/pwrite family of functions
This decreases the number of syscalls per read/write by half. Signed-off-by: Anton Ivanov <aivanov@brocade.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/os-Linux/file.c')
-rw-r--r--arch/um/os-Linux/file.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index 26e0164895e4..2db18cbbb0ea 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -264,6 +264,15 @@ int os_read_file(int fd, void *buf, int len)
return n;
}
+int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
+{
+ int n = pread(fd, buf, len, offset);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
int os_write_file(int fd, const void *buf, int len)
{
int n = write(fd, (void *) buf, len);
@@ -282,6 +291,16 @@ int os_sync_file(int fd)
return n;
}
+int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
+{
+ int n = pwrite(fd, (void *) buf, len, offset);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+
int os_file_size(const char *file, unsigned long long *size_out)
{
struct uml_stat buf;