[lvm-devel] master - dev-cache: skip VGID/LVID indexing if /sys/dev/block is not present
Peter Rajnoha
prajnoha at fedoraproject.org
Fri Apr 1 15:10:59 UTC 2016
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=42f04a0f77ee94b01d652d6c11d10e85aa46a897
Commit: 42f04a0f77ee94b01d652d6c11d10e85aa46a897
Parent: 9f28eb4c20ecb772f1b8a912c43f243d63a7e5f3
Author: Peter Rajnoha <prajnoha at redhat.com>
AuthorDate: Fri Apr 1 17:04:11 2016 +0200
Committer: Peter Rajnoha <prajnoha at redhat.com>
CommitterDate: Fri Apr 1 17:09:15 2016 +0200
dev-cache: skip VGID/LVID indexing if /sys/dev/block is not present
/sys/dev/block is available since kernel version 2.2.26 (~ 2008):
https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-dev
The VGID/LVID indexing code relies on this feature so skip indexing
if it's not available to avoid error messages about inability to open
/sys/dev/block directory.
We're not going to provide fallback code to read the /sys/block/
instead in this case as that's not that efficient - it needs extra
reads for getting major:minor and reading partitions would also
pose further reads and that's not worth it.
---
lib/device/dev-cache.c | 35 +++++++++++++++++++++++++++--------
1 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/lib/device/dev-cache.c b/lib/device/dev-cache.c
index 84bd85b..8461f40 100644
--- a/lib/device/dev-cache.c
+++ b/lib/device/dev-cache.c
@@ -818,9 +818,8 @@ static int _dev_cache_iterate_devs_for_index(void)
return r;
}
-static int _dev_cache_iterate_sysfs_for_index(void)
+static int _dev_cache_iterate_sysfs_for_index(const char *path)
{
- char path[PATH_MAX];
char devname[PATH_MAX];
DIR *d;
struct dirent *dirent;
@@ -830,11 +829,6 @@ static int _dev_cache_iterate_sysfs_for_index(void)
int partial_failure = 0;
int r = 0;
- if (dm_snprintf(path, sizeof(path), "%sdev/block", dm_sysfs_dir()) < 0) {
- log_error("_dev_cache_iterate_sysfs_for_index: dm_snprintf failed.");
- return 0;
- }
-
if (!(d = opendir(path))) {
log_sys_error("opendir", path);
return 0;
@@ -876,11 +870,36 @@ static int _dev_cache_iterate_sysfs_for_index(void)
int dev_cache_index_devs(void)
{
+ static int sysfs_has_dev_block = -1;
+ char path[PATH_MAX];
+
+ if (dm_snprintf(path, sizeof(path), "%sdev/block", dm_sysfs_dir()) < 0) {
+ log_error("dev_cache_index_devs: dm_snprintf failed.");
+ return 0;
+ }
+
+ /* Skip indexing if /sys/dev/block is not available.*/
+ if (sysfs_has_dev_block == -1) {
+ struct stat info;
+ if (stat(path, &info) == 0)
+ sysfs_has_dev_block = 1;
+ else {
+ if (errno == ENOENT) {
+ sysfs_has_dev_block = 0;
+ return 1;
+ } else {
+ log_sys_error("stat", path);
+ return 0;
+ }
+ }
+ } else if (!sysfs_has_dev_block)
+ return 1;
+
int with_udev = obtain_device_list_from_udev() &&
udev_get_library_context();
return with_udev ? _dev_cache_iterate_devs_for_index()
- : _dev_cache_iterate_sysfs_for_index();
+ : _dev_cache_iterate_sysfs_for_index(path);
}
#ifdef UDEV_SYNC_SUPPORT
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