[lvm-devel] master - devices: avoid extra open() syscall
Zdenek Kabelac
zkabelac at fedoraproject.org
Fri Mar 6 13:31:31 UTC 2015
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=6f68f4364b537cf52a27b5e53bb7f10de5a938fe
Commit: 6f68f4364b537cf52a27b5e53bb7f10de5a938fe
Parent: b48ff3b94e7cd771bbaf42f38b546054d02bc0f2
Author: Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate: Tue Mar 3 15:37:17 2015 +0100
Committer: Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Fri Mar 6 13:17:39 2015 +0100
devices: avoid extra open() syscall
If the device is already opened by lvm's device cache,
avoid extra syscall opening devices for obtaining its size.
---
WHATS_NEW | 1 +
lib/device/dev-io.c | 17 +++++++----------
lib/device/device.h | 2 +-
lib/report/report.c | 2 +-
4 files changed, 10 insertions(+), 12 deletions(-)
diff --git a/WHATS_NEW b/WHATS_NEW
index 46783e1..b62a632 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
Version 2.02.118 -
=================================
+ Save extra device open/close when scanning device for size.
Fix seg_monitor field to report status also for mirrors and thick snapshots.
Version 2.02.117 - 4th March 2015
diff --git a/lib/device/dev-io.c b/lib/device/dev-io.c
index 122b616..d712f31 100644
--- a/lib/device/dev-io.c
+++ b/lib/device/dev-io.c
@@ -289,25 +289,22 @@ static int _dev_get_size_file(const struct device *dev, uint64_t *size)
return 1;
}
-static int _dev_get_size_dev(const struct device *dev, uint64_t *size)
+static int _dev_get_size_dev(struct device *dev, uint64_t *size)
{
- int fd;
const char *name = dev_name(dev);
- if ((fd = open(name, O_RDONLY)) < 0) {
- log_sys_error("open", name);
- return 0;
- }
+ if (!dev_open_readonly(dev))
+ return_0;
- if (ioctl(fd, BLKGETSIZE64, size) < 0) {
+ if (ioctl(dev_fd(dev), BLKGETSIZE64, size) < 0) {
log_sys_error("ioctl BLKGETSIZE64", name);
- if (close(fd))
+ if (!dev_close(dev))
log_sys_error("close", name);
return 0;
}
*size >>= BLKSIZE_SHIFT; /* Convert to sectors */
- if (close(fd))
+ if (!dev_close(dev))
log_sys_error("close", name);
log_very_verbose("%s: size is %" PRIu64 " sectors", name, *size);
@@ -377,7 +374,7 @@ static int _dev_discard_blocks(struct device *dev, uint64_t offset_bytes, uint64
* Public functions
*---------------------------------------------------------------*/
-int dev_get_size(const struct device *dev, uint64_t *size)
+int dev_get_size(struct device *dev, uint64_t *size)
{
if (!dev)
return 0;
diff --git a/lib/device/device.h b/lib/device/device.h
index 0d38f96..dcc3713 100644
--- a/lib/device/device.h
+++ b/lib/device/device.h
@@ -94,7 +94,7 @@ int dev_ext_release(struct device *dev);
* All io should use these routines.
*/
int dev_get_block_size(struct device *dev, unsigned int *phys_block_size, unsigned int *block_size);
-int dev_get_size(const struct device *dev, uint64_t *size);
+int dev_get_size(struct device *dev, uint64_t *size);
int dev_get_read_ahead(struct device *dev, uint32_t *read_ahead);
int dev_discard_blocks(struct device *dev, uint64_t offset_bytes, uint64_t size_bytes);
diff --git a/lib/report/report.c b/lib/report/report.c
index 4ef2b04..86b0a54 100644
--- a/lib/report/report.c
+++ b/lib/report/report.c
@@ -965,7 +965,7 @@ static int _devsize_disp(struct dm_report *rh, struct dm_pool *mem,
struct dm_report_field *field,
const void *data, void *private)
{
- const struct device *dev = *(const struct device * const *) data;
+ struct device *dev = *(struct device * const *) data;
uint64_t size;
if (!dev || !dev->dev || !dev_get_size(dev, &size))
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