From 4ff8602c62ed908a7b7d5f51e863ed0ab4de2659 Mon Sep 17 00:00:00 2001
From: Chris Leech <cleech@redhat.com>
Date: Tue, 16 Feb 2016 16:45:26 -0800
Subject: [PATCH] remove sysfs attr_list
The global cache is not well designed, it quickly can grow to the point
where lookups take much longer than just doing the sysfs read in the
first place.
---
usr/host.c | 1 +
usr/session_info.c | 1 +
usr/sysfs.c | 62 ++++++++++++------------------------------------------
3 files changed, 16 insertions(+), 48 deletions(-)
diff --git a/usr/host.c b/usr/host.c
index f2052d3..6333490 100644
--- a/usr/host.c
+++ b/usr/host.c
@@ -274,6 +274,7 @@ int host_info_print(int info_level, uint32_t host_no)
printf("iSCSI Transport Class version %s\n",
version);
printf("version %s\n", ISCSI_VERSION_STR);
+ free(version);
}
flags |= SESSION_INFO_SCSI_DEVS;
diff --git a/usr/session_info.c b/usr/session_info.c
index 2f48e65..89422d8 100644
--- a/usr/session_info.c
+++ b/usr/session_info.c
@@ -390,6 +390,7 @@ int session_info_print(int info_level, struct session_info *info, int do_show)
printf("iSCSI Transport Class version %s\n",
version);
printf("version %s\n", ISCSI_VERSION_STR);
+ free(version);
}
flags |= (SESSION_INFO_SCSI_DEVS | SESSION_INFO_HOST_DEVS);
diff --git a/usr/sysfs.c b/usr/sysfs.c
index 6520bf6..efd4f74 100644
--- a/usr/sysfs.c
+++ b/usr/sysfs.c
@@ -63,15 +63,6 @@ char sysfs_path[PATH_SIZE];
/* device cache */
static LIST_HEAD(dev_list);
-/* attribute value cache */
-static LIST_HEAD(attr_list);
-
-struct sysfs_attr {
- struct list_head node;
- char path[PATH_SIZE];
- char *value; /* points to value_local if value is cached */
- char value_local[NAME_SIZE];
-};
int sysfs_init(void)
{
const char *env;
@@ -85,22 +76,14 @@ int sysfs_init(void)
dbg("sysfs_path='%s'", sysfs_path);
INIT_LIST_HEAD(&dev_list);
- INIT_LIST_HEAD(&attr_list);
return 0;
}
void sysfs_cleanup(void)
{
- struct sysfs_attr *attr_loop;
- struct sysfs_attr *attr_temp;
struct sysfs_device *dev_loop;
struct sysfs_device *dev_temp;
- list_for_each_entry_safe(attr_loop, attr_temp, &attr_list, node) {
- list_del_init(&attr_loop->node);
- free(attr_loop);
- }
-
list_for_each_entry_safe(dev_loop, dev_temp, &dev_list, node) {
list_del_init(&dev_loop->node);
free(dev_loop);
@@ -355,10 +338,7 @@ struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct sysfs_device
char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
{
char path_full[PATH_SIZE];
- const char *path;
char value[NAME_SIZE];
- struct sysfs_attr *attr_loop;
- struct sysfs_attr *attr;
struct stat statbuf;
int fd;
ssize_t size;
@@ -368,29 +348,10 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
if(sysfs_len >= sizeof(path_full))
sysfs_len = sizeof(path_full) - 1;
- path = &path_full[sysfs_len];
strlcat(path_full, devpath, sizeof(path_full));
strlcat(path_full, "/", sizeof(path_full));
strlcat(path_full, attr_name, sizeof(path_full));
- /* look for attribute in cache */
- list_for_each_entry(attr_loop, &attr_list, node) {
- if (strcmp(attr_loop->path, path) == 0) {
- dbg("found in cache '%s'", attr_loop->path);
- return attr_loop->value;
- }
- }
-
- /* store attribute in cache (also negatives are kept in cache) */
- dbg("new uncached attribute '%s'", path_full);
- attr = malloc(sizeof(struct sysfs_attr));
- if (attr == NULL)
- return NULL;
- memset(attr, 0x00, sizeof(struct sysfs_attr));
- strlcpy(attr->path, path, sizeof(attr->path));
- dbg("add to cache '%s'", path_full);
- list_add(&attr->node, &attr_list);
-
if (lstat(path_full, &statbuf) != 0) {
dbg("stat '%s' failed: %s", path_full, strerror(errno));
goto out;
@@ -408,8 +369,7 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
pos = strrchr(link_target, '/');
if (pos != NULL) {
dbg("cache '%s' with link value '%s'", path_full, value);
- strlcpy(attr->value_local, &pos[1], sizeof(attr->value_local));
- attr->value = attr->value_local;
+ strlcpy(value, &pos[1], NAME_SIZE);
}
}
goto out;
@@ -439,12 +399,8 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
/* got a valid value, store and return it */
value[size] = '\0';
remove_trailing_chars(value, '\n');
- dbg("cache '%s' with attribute value '%s'", path_full, value);
- strlcpy(attr->value_local, value, sizeof(attr->value_local));
- attr->value = attr->value_local;
-
out:
- return attr->value;
+ return strdup(value);
}
int sysfs_lookup_devpath_by_subsys_id(char *devpath_full, size_t len, const char *subsystem, const char *id)
@@ -567,8 +523,10 @@ char *sysfs_get_value(const char *id, char *subsys, char *param)
}
if (!strncmp(sysfs_value, "<NULL>", 6) ||
- !strncmp(sysfs_value, "(null)", 6))
+ !strncmp(sysfs_value, "(null)", 6)) {
+ free(sysfs_value);
return NULL;
+ }
return sysfs_value;
}
@@ -585,6 +543,7 @@ int sysfs_get_uint(char *id, char *subsys, char *param,
errno = 0;
*value = strtoul(sysfs_value, NULL, 0);
+ free(sysfs_value);
if (errno)
return errno;
return 0;
@@ -600,6 +559,7 @@ int sysfs_get_int(const char *id, char *subsys, char *param, int *value)
return EIO;
*value = atoi(sysfs_value);
+ free(sysfs_value);
return 0;
}
@@ -619,6 +579,7 @@ int sysfs_get_str(char *id, char *subsys, char *param, char *value,
sysfs_value[len - 1] = '\0';
strncpy(value, sysfs_value, value_size);
value[value_size - 1] = '\0';
+ free(sysfs_value);
return 0;
}
@@ -631,8 +592,11 @@ int sysfs_get_uint64(char *id, char *subsys, char *param, uint64_t *value)
if (!sysfs_value)
return EIO;
- if (sscanf(sysfs_value, "%" PRIu64 "\n", value) != 1)
+ if (sscanf(sysfs_value, "%" PRIu64 "\n", value) != 1) {
+ free(sysfs_value);
return EINVAL;
+ }
+ free(sysfs_value);
return 0;
}
@@ -647,6 +611,7 @@ int sysfs_get_uint8(char *id, char *subsys, char *param,
return EIO;
*value = (uint8_t)atoi(sysfs_value);
+ free(sysfs_value);
return 0;
}
@@ -661,6 +626,7 @@ int sysfs_get_uint16(char *id, char *subsys, char *param,
return EIO;
*value = (uint16_t)atoi(sysfs_value);
+ free(sysfs_value);
return 0;
}
--
2.5.0