From 96de1e663cda65ba9275afb1bc007f34e5068ba1 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 8 Nov 2005 21:39:39 -0800 Subject: [PATCH] [PATCH] md: fix some locking and module refcounting issues with md's use of sysfs 1/ I really should be using the __ATTR macros for defining attributes, so that the .owner field get set properly, otherwise modules can be removed while sysfs files are open. This also involves some name changes of _show routines. 2/ Always lock the mddev (against reconfiguration) for all sysfs attribute access. This easily avoid certain races and is completely consistant with other interfaces (ioctl and /proc/mdstat both always lock against reconfiguration). 3/ raid5 attributes must check that the 'conf' structure actually exists (the array could have been stopped while an attribute file was open). 4/ A missing 'kfree' from when the raid5_conf_t was converted to have a kobject embedded, and then converted back again. Signed-off-by: Neil Brown Acked-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/md.c | 62 +++++++++++++++++++++------------------------- drivers/md/raid5.c | 30 +++++++++++++--------- 2 files changed, 46 insertions(+), 46 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 2b5928976095..b2d8813ed716 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1504,7 +1504,7 @@ struct rdev_sysfs_entry { }; static ssize_t -rdev_show_state(mdk_rdev_t *rdev, char *page) +state_show(mdk_rdev_t *rdev, char *page) { char *sep = ""; int len=0; @@ -1525,13 +1525,11 @@ rdev_show_state(mdk_rdev_t *rdev, char *page) return len+sprintf(page+len, "\n"); } -static struct rdev_sysfs_entry rdev_state = { - .attr = {.name = "state", .mode = S_IRUGO }, - .show = rdev_show_state, -}; +static struct rdev_sysfs_entry +rdev_state = __ATTR_RO(state); static ssize_t -rdev_show_super(mdk_rdev_t *rdev, char *page) +super_show(mdk_rdev_t *rdev, char *page) { if (rdev->sb_loaded && rdev->sb_size) { memcpy(page, page_address(rdev->sb_page), rdev->sb_size); @@ -1539,10 +1537,8 @@ rdev_show_super(mdk_rdev_t *rdev, char *page) } else return 0; } -static struct rdev_sysfs_entry rdev_super = { - .attr = {.name = "super", .mode = S_IRUGO }, - .show = rdev_show_super, -}; +static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super); + static struct attribute *rdev_default_attrs[] = { &rdev_state.attr, &rdev_super.attr, @@ -1728,7 +1724,7 @@ static void analyze_sbs(mddev_t * mddev) } static ssize_t -md_show_level(mddev_t *mddev, char *page) +level_show(mddev_t *mddev, char *page) { mdk_personality_t *p = mddev->pers; if (p == NULL) @@ -1739,21 +1735,15 @@ md_show_level(mddev_t *mddev, char *page) return sprintf(page, "%s\n", p->name); } -static struct md_sysfs_entry md_level = { - .attr = {.name = "level", .mode = S_IRUGO }, - .show = md_show_level, -}; +static struct md_sysfs_entry md_level = __ATTR_RO(level); static ssize_t -md_show_rdisks(mddev_t *mddev, char *page) +raid_disks_show(mddev_t *mddev, char *page) { return sprintf(page, "%d\n", mddev->raid_disks); } -static struct md_sysfs_entry md_raid_disks = { - .attr = {.name = "raid_disks", .mode = S_IRUGO }, - .show = md_show_rdisks, -}; +static struct md_sysfs_entry md_raid_disks = __ATTR_RO(raid_disks); static ssize_t md_show_scan(mddev_t *mddev, char *page) @@ -1782,10 +1772,10 @@ md_store_scan(mddev_t *mddev, const char *page, size_t len) if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || test_bit(MD_RECOVERY_NEEDED, &mddev->recovery)) return -EBUSY; - down(&mddev->reconfig_sem); + if (mddev->pers && mddev->pers->sync_request) canscan=1; - up(&mddev->reconfig_sem); + if (!canscan) return -EINVAL; @@ -1801,22 +1791,18 @@ md_store_scan(mddev_t *mddev, const char *page, size_t len) } static ssize_t -md_show_mismatch(mddev_t *mddev, char *page) +mismatch_cnt_show(mddev_t *mddev, char *page) { return sprintf(page, "%llu\n", (unsigned long long) mddev->resync_mismatches); } -static struct md_sysfs_entry md_scan_mode = { - .attr = {.name = "scan_mode", .mode = S_IRUGO|S_IWUSR }, - .show = md_show_scan, - .store = md_store_scan, -}; +static struct md_sysfs_entry +md_scan_mode = __ATTR(scan_mode, S_IRUGO|S_IWUSR, md_show_scan, md_store_scan); -static struct md_sysfs_entry md_mismatches = { - .attr = {.name = "mismatch_cnt", .mode = S_IRUGO }, - .show = md_show_mismatch, -}; + +static struct md_sysfs_entry +md_mismatches = __ATTR_RO(mismatch_cnt); static struct attribute *md_default_attrs[] = { &md_level.attr, @@ -1831,10 +1817,14 @@ md_attr_show(struct kobject *kobj, struct attribute *attr, char *page) { struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr); mddev_t *mddev = container_of(kobj, struct mddev_s, kobj); + ssize_t rv; if (!entry->show) return -EIO; - return entry->show(mddev, page); + mddev_lock(mddev); + rv = entry->show(mddev, page); + mddev_unlock(mddev); + return rv; } static ssize_t @@ -1843,10 +1833,14 @@ md_attr_store(struct kobject *kobj, struct attribute *attr, { struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr); mddev_t *mddev = container_of(kobj, struct mddev_s, kobj); + ssize_t rv; if (!entry->store) return -EIO; - return entry->store(mddev, page, length); + mddev_lock(mddev); + rv = entry->store(mddev, page, length); + mddev_unlock(mddev); + return rv; } static void md_free(struct kobject *ko) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 51003b008de7..e2a40283e323 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1746,7 +1746,10 @@ static ssize_t raid5_show_stripe_cache_size(mddev_t *mddev, char *page) { raid5_conf_t *conf = mddev_to_conf(mddev); - return sprintf(page, "%d\n", conf->max_nr_stripes); + if (conf) + return sprintf(page, "%d\n", conf->max_nr_stripes); + else + return 0; } static ssize_t @@ -1757,6 +1760,8 @@ raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) int new; if (len >= PAGE_SIZE) return -EINVAL; + if (!conf) + return -ENODEV; new = simple_strtoul(page, &end, 10); if (!*page || (*end && *end != '\n') ) @@ -1777,23 +1782,23 @@ raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) return len; } -static struct md_sysfs_entry raid5_stripecache_size = { - .attr = {.name = "stripe_cache_size", .mode = S_IRUGO | S_IWUSR }, - .show = raid5_show_stripe_cache_size, - .store = raid5_store_stripe_cache_size, -}; +static struct md_sysfs_entry +raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, + raid5_show_stripe_cache_size, + raid5_store_stripe_cache_size); static ssize_t -raid5_show_stripe_cache_active(mddev_t *mddev, char *page) +stripe_cache_active_show(mddev_t *mddev, char *page) { raid5_conf_t *conf = mddev_to_conf(mddev); - return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); + if (conf) + return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); + else + return 0; } -static struct md_sysfs_entry raid5_stripecache_active = { - .attr = {.name = "stripe_cache_active", .mode = S_IRUGO}, - .show = raid5_show_stripe_cache_active, -}; +static struct md_sysfs_entry +raid5_stripecache_active = __ATTR_RO(stripe_cache_active); static struct attribute *raid5_attrs[] = { &raid5_stripecache_size.attr, @@ -1981,6 +1986,7 @@ static int stop(mddev_t *mddev) free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); + kfree(conf); mddev->private = NULL; return 0; } -- 2.20.1