parted/libparted-open-the-device-RO-and-lazily-switch-to-RW.patch
Petr Uzel f9709be99e - Update parted-implement-wipesignatures-option.patch:
- Move functionality to libparted (bsc#980384)
- libparted: open the device RO and lazily switch to RW only if
  necessary (bsc#979275)
  - libparted-open-the-device-RO-and-lazily-switch-to-RW.patch

OBS-URL: https://build.opensuse.org/package/show/Base:System/parted?expand=0&rev=119
2016-05-26 13:48:48 +00:00

127 lines
3.6 KiB
Diff

From b9420b8e618c8ad988c410e4289273ac962ec918 Mon Sep 17 00:00:00 2001
From: Petr Uzel <petr.uzel@suse.cz>
Date: Thu, 26 May 2016 09:28:21 +0200
Subject: [PATCH] libparted: open the device RO and lazily switch to RW only if
necessary
Avoid useless udev events triggered by opening the device RW
for purely read-only operations.
References: https://bugzilla.novell.com/show_bug.cgi?id=979275
Author: Michael Matz <matz@suse.de>
---
libparted/arch/linux.c | 33 ++++++++++++++++++++++++++++++---
libparted/arch/linux.h | 1 +
2 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
index 326b956..0a50452 100644
--- a/libparted/arch/linux.c
+++ b/libparted/arch/linux.c
@@ -294,6 +294,9 @@ static unsigned int _device_get_partition_range(PedDevice const* dev);
static int _device_open (PedDevice* dev, int flags);
static int _device_open_ro (PedDevice* dev);
static int _device_close (PedDevice* dev);
+static int linux_close (PedDevice* dev);
+static void _flush_cache (PedDevice* dev);
+
static int
_read_fd (int fd, char **buf)
@@ -441,6 +444,24 @@ _is_virtblk_major (int major)
return _major_type_in_devices (major, "virtblk");
}
+static void
+_ensure_read_write (PedDevice *dev)
+{
+ PED_ASSERT (dev != NULL);
+ LinuxSpecific* arch_specific = LINUX_SPECIFIC (dev);
+
+ if (arch_specific->rw)
+ return;
+
+ if (!linux_close(dev))
+ return;
+
+ if (!_device_open (dev, RW_MODE))
+ return;
+
+ _flush_cache (dev);
+}
+
#ifdef ENABLE_DEVICE_MAPPER
static int
_dm_task_run_wait (struct dm_task *task, uint32_t cookie)
@@ -1604,6 +1625,7 @@ _flush_cache (PedDevice* dev)
if (dev->read_only)
return;
+ _ensure_read_write (dev);
dev->dirty = 0;
ioctl (arch_specific->fd, BLKFLSBUF);
@@ -1647,7 +1669,7 @@ _device_open_ro (PedDevice* dev)
static int
linux_open (PedDevice* dev)
{
- return _device_open (dev, RW_MODE);
+ return _device_open (dev, RD_MODE);
}
static int
@@ -1685,10 +1707,12 @@ retry:
}
} else {
dev->read_only = 0;
+ if (flags == WR_MODE || flags == RW_MODE)
+ arch_specific->rw = 1;
+ else
+ arch_specific->rw = 0;
}
- _flush_cache (dev);
-
return 1;
}
@@ -1920,6 +1944,7 @@ _write_lastoddsector (PedDevice* dev, const void* buffer)
PED_ASSERT(dev != NULL);
PED_ASSERT(buffer != NULL);
+ _ensure_read_write (dev);
arch_specific = LINUX_SPECIFIC (dev);
@@ -1968,6 +1993,7 @@ linux_write (PedDevice* dev, const void* buffer, PedSector start,
return 1;
}
+ _ensure_read_write (dev);
if (_get_linux_version() < KERNEL_VERSION (2,6,0)) {
/* Kludge. This is necessary to read/write the last
block of an odd-sized disk, until Linux 2.5.x kernel fixes.
@@ -2497,6 +2523,7 @@ _blkpg_part_command (PedDevice* dev, struct blkpg_partition* part, int op)
LinuxSpecific* arch_specific = LINUX_SPECIFIC (dev);
struct blkpg_ioctl_arg ioctl_arg;
+ _ensure_read_write (dev);
ioctl_arg.op = op;
ioctl_arg.flags = 0;
ioctl_arg.datalen = sizeof (struct blkpg_partition);
diff --git a/libparted/arch/linux.h b/libparted/arch/linux.h
index 95def1f..926f7e2 100644
--- a/libparted/arch/linux.h
+++ b/libparted/arch/linux.h
@@ -30,6 +30,7 @@ struct _LinuxSpecific {
int fd;
int major;
int minor;
+ int rw;
char* dmtype; /**< device map target type */
#if defined __s390__ || defined __s390x__
unsigned int real_sector_size;
--
1.8.4.5