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authorAmaury Pouly <amaury.pouly@gmail.com>2020-01-12 23:12:18 +0100
committerAmaury Pouly <amaury.pouly@gmail.com>2020-01-12 23:12:18 +0100
commitee15e45224d94ff84471e5ac4c05eb189dbe5980 (patch)
tree63991bcff06889b92cc3b4433dc0cde0f1930d00 /utils
parent9e94a5eadcdbef406c22833b8afa9e380b698fdf (diff)
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nwztool/scsitool: rewrite device detection on linux to make it simpler
Change-Id: I8f393a53ea64c82f05e437923bcba05aa8a7a75c
Diffstat (limited to 'utils')
-rw-r--r--utils/scsi/rbscsi.c130
1 files changed, 27 insertions, 103 deletions
diff --git a/utils/scsi/rbscsi.c b/utils/scsi/rbscsi.c
index 8e15f1fd6a..adfecd8d0a 100644
--- a/utils/scsi/rbscsi.c
+++ b/utils/scsi/rbscsi.c
@@ -157,52 +157,10 @@ void rb_scsi_close(rb_scsi_device_t dev)
free(dev);
}
-static int is_hctl(const char *name)
-{
- char *end;
- strtoul(name, &end, 0); /* h */
- if(*end != ':')
- return 0;
- strtoul(end + 1, &end, 0); /* c */
- if(*end != ':')
- return 0;
- strtoul(end + 1, &end, 0); /* t */
- if(*end != ':')
- return 0;
- strtoul(end + 1, &end, 0); /* l */
- return *end == 0;
-}
-
-static int _resolve_link_dev_path(char *path, size_t pathsz)
-{
- /* make sure it is a directory */
- struct stat st;
- if(stat(path, &st) < 0)
- return 0;
- if(!S_ISDIR(st.st_mode))
- return 0;
- if(chdir(path) < 0)
- return 0;
- if(getcwd(path, pathsz) == NULL)
- return 0;
- return 1;
-}
-
-static int resolve_link_dev_path(char *path, size_t pathsz)
-{
- /* change directory, ask the current path and resolve current directory */
- char curdir[PATH_MAX];
- if(getcwd(curdir, sizeof(curdir)) == NULL)
- return 0;
- int ret = _resolve_link_dev_path(path, pathsz);
- chdir(curdir);
- return ret;
-}
-
+/* find the first entry of a directory (which is expended to contain only one) and turn
+ * it into a /dev/ path */
static int scan_resolve_first_dev_path(char *path, size_t pathsz)
{
- size_t pathlen = strlen(path);
- char *pathend = path + pathlen;
DIR *dir = opendir(path);
if(dir == NULL)
return 0;
@@ -212,13 +170,8 @@ static int scan_resolve_first_dev_path(char *path, size_t pathsz)
{
if(!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
continue;
- /* we found the entry, if it is a symlink, resolve it, otherwise it must be a directory */
- if(d->d_type == DT_LNK)
- {
- snprintf(pathend, pathsz - pathlen, "/%s", d->d_name);
- ret = resolve_link_dev_path(path, pathsz);
- }
- else if(d->d_type == DT_DIR)
+ /* we expect a directory, but it could be a symlink, only the name matters */
+ if(d->d_type == DT_LNK || d->d_type == DT_DIR)
{
snprintf(path, pathsz, "/dev/%s", d->d_name);
ret = 1;
@@ -229,33 +182,6 @@ static int scan_resolve_first_dev_path(char *path, size_t pathsz)
return ret;
}
-static int scan_resolve_dev_path(char *path, size_t pathsz, const char *match)
-{
- size_t pathlen = strlen(path);
- char *pathend = path + pathlen;
- DIR *dir = opendir(path);
- if(dir == NULL)
- return 0;
- struct dirent *d;
- int ret = 0;
- while((d = readdir(dir)))
- {
- if(strcmp(d->d_name, match))
- continue;
- /* we found the entry, there are two case:
- * - directory: we need to scan it and find the first entry
- * - symlink: we need to see where it goes and extract the basename */
- snprintf(pathend, pathsz - pathlen, "/%s", d->d_name);
- if(d->d_type == DT_DIR)
- ret = scan_resolve_first_dev_path(path, pathsz);
- else if(d->d_type == DT_LNK)
- ret = resolve_link_dev_path(path, pathsz);
- break;
- }
- closedir(dir);
- return ret;
-}
-
static char *read_file_or_null(const char *path)
{
FILE *f = fopen(path, "r");
@@ -277,9 +203,9 @@ static char *read_file_or_null(const char *path)
struct rb_scsi_devent_t *rb_scsi_list(void)
{
- /* list devices in /sys/bus/scsi/devices
- * we only keep entries of the form h:c:t:l */
-#define SYS_SCSI_DEV_PATH "/sys/bus/scsi/devices"
+ /* list devices in /sys/class/scsi_generic
+ * we only keep entries of the form sgX */
+#define SYS_SCSI_DEV_PATH "/sys/class/scsi_generic"
DIR *dir = opendir(SYS_SCSI_DEV_PATH);
if(dir == NULL)
return NULL;
@@ -292,31 +218,29 @@ struct rb_scsi_devent_t *rb_scsi_list(void)
{
if(!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
continue;
- /* make sure the name is of the form h:c:t:l, we do not want targets or hosts */
- if(!is_hctl(d->d_name))
+ /* make sure the name is of the form sgX, and extract X */
+ int sg_idx;
+ if(sscanf(d->d_name, "sg%d", &sg_idx) != 1)
continue;
- /* we now need to scan the directory to find the block and scsi generic device path:
- * block: there should be a 'block' entry
- * scsi: there should be a 'scsi_generic' entry
- * Both entries can either be a symlink to the devide, or a directory with a single entry */
- char scsi_path[PATH_MAX];
- snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s", d->d_name);
- if(!scan_resolve_dev_path(scsi_path, sizeof(scsi_path), "scsi_generic"))
- continue;
- char block_path[PATH_MAX];
- snprintf(block_path, sizeof(block_path), SYS_SCSI_DEV_PATH "/%s", d->d_name);
- if(!scan_resolve_dev_path(block_path, sizeof(block_path), "block"))
- block_path[0] = 0;
dev = realloc(dev, (2 + nr_dev) * sizeof(struct rb_scsi_devent_t));
- dev[nr_dev].scsi_path = strdup(scsi_path);
- dev[nr_dev].block_path = block_path[0] == 0 ? NULL : strdup(block_path);
+
+ char path[PATH_MAX];
+ snprintf(path, sizeof(path), "/dev/sg%d", sg_idx);
+ dev[nr_dev].scsi_path = strdup(path);
+ /* /sys/class/scsi_generic/sgX is a folder containing a subfolder 'device' that contains
+ * - a 'block' folder with a single entry: the block device
+ * - the vendor/model/rev files */
+ snprintf(path, sizeof(path), SYS_SCSI_DEV_PATH "/sg%d/device/block", sg_idx);
+ if(!scan_resolve_first_dev_path(path, sizeof(path)))
+ path[0] = 0;
+ dev[nr_dev].block_path = path[0] == 0 ? NULL : strdup(path);
/* fill vendor/model/rev */
- snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s/vendor", d->d_name);
- dev[nr_dev].vendor = read_file_or_null(scsi_path);
- snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s/model", d->d_name);
- dev[nr_dev].model = read_file_or_null(scsi_path);
- snprintf(scsi_path, sizeof(scsi_path), SYS_SCSI_DEV_PATH "/%s/rev", d->d_name);
- dev[nr_dev].rev = read_file_or_null(scsi_path);
+ snprintf(path, sizeof(path), SYS_SCSI_DEV_PATH "/sg%d/device/vendor", sg_idx);
+ dev[nr_dev].vendor = read_file_or_null(path);
+ snprintf(path, sizeof(path), SYS_SCSI_DEV_PATH "/sg%d/device/model", sg_idx);
+ dev[nr_dev].model = read_file_or_null(path);
+ snprintf(path, sizeof(path), SYS_SCSI_DEV_PATH "/sg%d/device/rev", sg_idx);
+ dev[nr_dev].rev = read_file_or_null(path);
/* sentinel */
dev[++nr_dev].scsi_path = NULL;