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authordsteklof@us.ibm.com <dsteklof@us.ibm.com>2003-11-12 05:37:24 -0800
committerGreg KH <gregkh@suse.de>2005-04-26 21:06:23 -0700
commit8d8172514d8c29cd5b2c51a0825268b823eb8294 (patch)
tree8b1ede69955e047462e41475e8b8803b922650d5
parente308ebb70f9d1e389577c2a8829cf2d210cd6a19 (diff)
[PATCH] patch for libsysfs sysfs directory handling
Here's a quick patch to: 1) Add an environment variable "SYSFS_PATH" that libsysfs will check for when getting mount point before searching system's sysfs mount point. 2) A quick fix to sysfs_get_link where the bug was. I have tested this out with libsysfs and with udev. I couldn't test with klibc because I haven't got the tree to build with klibc without my changes either. I made the link but get an error finding linux/linits.h. I will figure that out. Please have a look at the patch. If it's agreeable, please test it. I really want to add some generic path manipulation functions for the sysfs_get_link error, rather than my patch's hack. But, I haven't had time yet to do that. You really sounded like you needed this for testing, so I'm sending it out to you. I should probably add a function to set the env variable(?).
-rw-r--r--libsysfs/libsysfs.h1
-rw-r--r--libsysfs/sysfs_utils.c42
2 files changed, 30 insertions, 13 deletions
diff --git a/libsysfs/libsysfs.h b/libsysfs/libsysfs.h
index ccb9898cb5..b3ffc467d0 100644
--- a/libsysfs/libsysfs.h
+++ b/libsysfs/libsysfs.h
@@ -40,6 +40,7 @@
#define SYSFS_DRIVERS_NAME "drivers"
#define SYSFS_NAME_ATTRIBUTE "name"
#define SYSFS_UNKNOWN "unknown"
+#define SYSFS_PATH_ENV "SYSFS_PATH"
/* Some "block" subsystem specific #defines */
#define SYSFS_QUEUE_NAME "queue"
diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c
index f1303cacb3..3e50bc6120 100644
--- a/libsysfs/sysfs_utils.c
+++ b/libsysfs/sysfs_utils.c
@@ -84,12 +84,18 @@ static int sysfs_get_fs_mnt_path(const unsigned char *fs_type,
*/
int sysfs_get_mnt_path(unsigned char *mnt_path, size_t len)
{
- int ret = -1;
+ char *sysfs_path = NULL;
+ int ret = 0;
- if (mnt_path != NULL)
- ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
- else
+ if (mnt_path == NULL) {
errno = EINVAL;
+ return -1;
+ }
+ sysfs_path = getenv(SYSFS_PATH_ENV);
+ if (sysfs_path != NULL)
+ strncpy(mnt_path, sysfs_path, len);
+ else
+ ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
return ret;
}
@@ -130,7 +136,8 @@ int sysfs_get_link(const unsigned char *path, unsigned char *target, size_t len)
{
unsigned char devdir[SYSFS_PATH_MAX];
unsigned char linkpath[SYSFS_PATH_MAX];
- unsigned char *d = NULL;
+ unsigned char *d = NULL, *s = NULL;
+ int slashes = 0, count = 0;
if (path == NULL || target == NULL) {
errno = EINVAL;
@@ -139,12 +146,8 @@ int sysfs_get_link(const unsigned char *path, unsigned char *target, size_t len)
memset(devdir, 0, SYSFS_PATH_MAX);
memset(linkpath, 0, SYSFS_PATH_MAX);
+ strncpy(devdir, path, SYSFS_PATH_MAX);
- if ((sysfs_get_mnt_path(devdir, SYSFS_PATH_MAX)) != 0) {
- dprintf("Sysfs not supported on this system\n");
- return -1;
- }
-
if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
return -1;
}
@@ -152,12 +155,25 @@ int sysfs_get_link(const unsigned char *path, unsigned char *target, size_t len)
d = linkpath;
/* getting rid of leading "../.." */
- while (*d == '/' || *d == '.')
+ while (*d == '/' || *d == '.') {
+ if (*d == '/')
+ slashes++;
d++;
+ }
d--;
-
- strcat(devdir, d);
+
+ s = &devdir[strlen(devdir)-1];
+ while (s != NULL && count != (slashes+1)) {
+ s--;
+ if (*s == '/')
+ count++;
+ }
+
+ if (s == NULL)
+ return -1;
+
+ strncpy(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
strncpy(target, devdir, len);
return 0;