From 07562d6ecf64f708a3a20388200ec8bd9c5a3774 Mon Sep 17 00:00:00 2001 From: "greg@kroah.com" Date: Wed, 24 Dec 2003 19:44:19 -0800 Subject: [PATCH] [PATCH] fix long delay for all devices in namedev Now we only sleep if we can't find the device file, and we have a hack to sleep for 1 second if we are on a partition. This will be removed when the libsysfs change gets made... --- namedev.c | 112 ++++++++++++++++++++++++++---------------------------- 1 file changed, 53 insertions(+), 59 deletions(-) diff --git a/namedev.c b/namedev.c index c77b0f8ef..1e600bbe6 100644 --- a/namedev.c +++ b/namedev.c @@ -624,57 +624,51 @@ static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_de struct sysfs_device *sysfs_device; struct sysfs_class_device *class_dev_parent; int loop; - - /* FIXME!!! */ - /* This is needed here as we can easily out-race the placement of the - * device symlink by the kernel. The call to sleep(1); will be removed - * once libsysfs can be queried for sysfs_get_classdev_device() - * multiple times and have it return the proper information when the - * class device really shows up. For now, we live with the time - * delay... + char filename[SYSFS_PATH_MAX + 6]; + int retval; + char *temp; + int partition = 0; + + /* Figure out where the device symlink is at. For char devices this will + * always be in the class_dev->path. But for block devices, it's different. + * The main block device will have the device symlink in it's path, but + * all partitions have the symlink in its parent directory. + * But we need to watch out for block devices that do not have parents, yet + * look like a partition (fd0, loop0, etc.) They all do not have a device + * symlink yet. We do sit and spin on waiting for them right now, we should + * possibly have a whitelist for these devices here... */ - sleep(1); + strcpy(filename, class_dev->path); + dbg("filename = %s", filename); + if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) { + if (isdigit(class_dev->path[strlen(class_dev->path)-1])) { + temp = strrchr(filename, '/'); + if (temp) { + partition = 1; + *temp = 0x00; + char *temp2 = strrchr(filename, '/'); + dbg("temp2 = %s", temp2); + if (temp2 && (strcmp(temp2, "/block") == 0)) { + /* oops, we have no parent block device, so go back to original directory */ + strcpy(filename, class_dev->path); + partition = 0; + } + } + } + } + strcat(filename, "/device"); -#if 0 /* FIXME - Something like this could also work, but for some reason doesn't, - I also tried just stat() on the device symlink, but that still - has nasty races, I'm probably doing something stupid... :( */ - loop = 10; + loop = 2; while (loop--) { struct stat buf; - int retval; - char filename[SYSFS_PATH_MAX + 6]; - - strcpy(filename, class_dev->path); - strcat(filename, "/device"); dbg("looking for '%s'", filename); retval = stat(filename, &buf); if (!retval) break; - - /* bah, let's go backwards up a level to see if the device is there, - * as block partitions don't point to the physical device. Need to fix that - * up in the kernel... - */ - if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) { - if (isdigit(class_dev->path[strlen(class_dev->path)-1])) { - class_dev_parent = sysfs_get_classdev_parent(class_dev); - if (class_dev_parent == NULL) { - dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name); - } else { - strcpy(filename, class_dev_parent->path); - strcat(filename, "/device"); - dbg("looking for '%s'", filename); - retval = stat(filename, &buf); - if (!retval) - break; - } - } - } /* sleep to give the kernel a chance to create the device file */ sleep(1); } -#endif + loop = 1; /* FIXME put a real value in here for when everything is fixed... */ while (loop--) { /* find the sysfs_device for this class device */ @@ -683,28 +677,28 @@ static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_de if (sysfs_device != NULL) goto exit; - /* bah, let's go backwards up a level to see if the device is there, - * as block partitions don't point to the physical device. Need to fix that - * up in the kernel... - */ - if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) { - dbg("looking at block device"); - if (isdigit(class_dev->path[strlen(class_dev->path)-1])) { - dbg("really is a partition"); - class_dev_parent = sysfs_get_classdev_parent(class_dev); - if (class_dev_parent == NULL) { - dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name); - } else { - dbg("class_dev_parent->name='%s'", class_dev_parent->name); - sysfs_device = sysfs_get_classdev_device(class_dev_parent); - if (sysfs_device != NULL) - goto exit; - } + /* if it's a partition, we need to get the parent device */ + if (partition) { + /* FIXME HACK HACK HACK HACK + * for some reason partitions need this extra sleep here, in order + * to wait for the device properly. Once the libsysfs code is + * fixed properly, this sleep should go away, and we can just loop above. + */ + sleep(1); + dbg("really is a partition"); + class_dev_parent = sysfs_get_classdev_parent(class_dev); + if (class_dev_parent == NULL) { + dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name); + } else { + dbg("class_dev_parent->name='%s'", class_dev_parent->name); + sysfs_device = sysfs_get_classdev_device(class_dev_parent); + if (sysfs_device != NULL) + goto exit; } } /* sleep to give the kernel a chance to create the link */ - sleep(1); - + /* FIXME remove comment... + sleep(1); */ } dbg("Timed out waiting for device symlink, continuing on anyway..."); exit: -- 2.30.2