From 413ec8057bc3d368574abd05dd27e747063b2f59 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 13 Jan 2022 00:14:32 +0000 Subject: loop: remove redundant initialization of pointer node The pointer node is being initialized with a value that is never read, it is being re-assigned the same value a little futher on. Remove the redundant initialization. Cleans up clang scan warning: drivers/block/loop.c:823:19: warning: Value stored to 'node' during its initialization is never read [deadcode.DeadStores] Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20220113001432.1331871-1-colin.i.king@gmail.com Signed-off-by: Jens Axboe --- drivers/block/loop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index b1b05c45c07c..01cbbfc4e9e2 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -820,7 +820,7 @@ static inline int queue_on_root_worker(struct cgroup_subsys_state *css) static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) { - struct rb_node **node = &(lo->worker_tree.rb_node), *parent = NULL; + struct rb_node **node, *parent = NULL; struct loop_worker *cur_worker, *worker = NULL; struct work_struct *work; struct list_head *cmd_list; -- cgit v1.2.3 From a6431e351c6ec5bb6800787d259b343088f369a3 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 13 Jan 2022 00:05:45 +0000 Subject: aoe: remove redundant assignment on variable n The variable n is being bit-wise or'd with a value and reassigned before being returned. The update of n is redundant, replace the |= operator with | instead. Cleans up clang scan warning: drivers/block/aoe/aoecmd.c:125:9: warning: Although the value stored to 'n' is used in the enclosing expression, the value is never actually read from 'n' [deadcode.DeadStores] Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20220113000545.1307091-1-colin.i.king@gmail.com Signed-off-by: Jens Axboe --- drivers/block/aoe/aoecmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index 588889bea7c3..6af111f568e4 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -122,7 +122,7 @@ newtag(struct aoedev *d) register ulong n; n = jiffies & 0xffff; - return n |= (++d->lasttag & 0x7fff) << 16; + return n | (++d->lasttag & 0x7fff) << 16; } static u32 -- cgit v1.2.3 From 00358933f66c44d511368a57eb421e172447cfb9 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Thu, 6 Jan 2022 18:53:16 +0900 Subject: brd: remove brd_devices_mutex mutex If brd_alloc() from brd_probe() is called before brd_alloc() from brd_init() is called, module loading will fail with -EEXIST error. To close this race, call __register_blkdev() just before leaving brd_init(). Then, we can remove brd_devices_mutex mutex, for brd_device list will no longer be accessed concurrently. Signed-off-by: Tetsuo Handa Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/6b074af7-c165-4fab-b7da-8270a4f6f6cd@i-love.sakura.ne.jp Signed-off-by: Jens Axboe --- drivers/block/brd.c | 73 ++++++++++++++++++++++------------------------------- 1 file changed, 30 insertions(+), 43 deletions(-) (limited to 'drivers') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 8fe2e4289dae..6e3f2f0d2352 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -362,7 +362,6 @@ __setup("ramdisk_size=", ramdisk_size); * (should share code eventually). */ static LIST_HEAD(brd_devices); -static DEFINE_MUTEX(brd_devices_mutex); static struct dentry *brd_debugfs_dir; static int brd_alloc(int i) @@ -372,21 +371,14 @@ static int brd_alloc(int i) char buf[DISK_NAME_LEN]; int err = -ENOMEM; - mutex_lock(&brd_devices_mutex); - list_for_each_entry(brd, &brd_devices, brd_list) { - if (brd->brd_number == i) { - mutex_unlock(&brd_devices_mutex); + list_for_each_entry(brd, &brd_devices, brd_list) + if (brd->brd_number == i) return -EEXIST; - } - } brd = kzalloc(sizeof(*brd), GFP_KERNEL); - if (!brd) { - mutex_unlock(&brd_devices_mutex); + if (!brd) return -ENOMEM; - } brd->brd_number = i; list_add_tail(&brd->brd_list, &brd_devices); - mutex_unlock(&brd_devices_mutex); spin_lock_init(&brd->brd_lock); INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC); @@ -429,9 +421,7 @@ static int brd_alloc(int i) out_cleanup_disk: blk_cleanup_disk(disk); out_free_dev: - mutex_lock(&brd_devices_mutex); list_del(&brd->brd_list); - mutex_unlock(&brd_devices_mutex); kfree(brd); return err; } @@ -441,15 +431,19 @@ static void brd_probe(dev_t dev) brd_alloc(MINOR(dev) / max_part); } -static void brd_del_one(struct brd_device *brd) +static void brd_cleanup(void) { - del_gendisk(brd->brd_disk); - blk_cleanup_disk(brd->brd_disk); - brd_free_pages(brd); - mutex_lock(&brd_devices_mutex); - list_del(&brd->brd_list); - mutex_unlock(&brd_devices_mutex); - kfree(brd); + struct brd_device *brd, *next; + + debugfs_remove_recursive(brd_debugfs_dir); + + list_for_each_entry_safe(brd, next, &brd_devices, brd_list) { + del_gendisk(brd->brd_disk); + blk_cleanup_disk(brd->brd_disk); + brd_free_pages(brd); + list_del(&brd->brd_list); + kfree(brd); + } } static inline void brd_check_and_reset_par(void) @@ -473,9 +467,18 @@ static inline void brd_check_and_reset_par(void) static int __init brd_init(void) { - struct brd_device *brd, *next; int err, i; + brd_check_and_reset_par(); + + brd_debugfs_dir = debugfs_create_dir("ramdisk_pages", NULL); + + for (i = 0; i < rd_nr; i++) { + err = brd_alloc(i); + if (err) + goto out_free; + } + /* * brd module now has a feature to instantiate underlying device * structure on-demand, provided that there is an access dev node. @@ -491,28 +494,16 @@ static int __init brd_init(void) * dynamically. */ - if (__register_blkdev(RAMDISK_MAJOR, "ramdisk", brd_probe)) - return -EIO; - - brd_check_and_reset_par(); - - brd_debugfs_dir = debugfs_create_dir("ramdisk_pages", NULL); - - for (i = 0; i < rd_nr; i++) { - err = brd_alloc(i); - if (err) - goto out_free; + if (__register_blkdev(RAMDISK_MAJOR, "ramdisk", brd_probe)) { + err = -EIO; + goto out_free; } pr_info("brd: module loaded\n"); return 0; out_free: - unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); - debugfs_remove_recursive(brd_debugfs_dir); - - list_for_each_entry_safe(brd, next, &brd_devices, brd_list) - brd_del_one(brd); + brd_cleanup(); pr_info("brd: module NOT loaded !!!\n"); return err; @@ -520,13 +511,9 @@ out_free: static void __exit brd_exit(void) { - struct brd_device *brd, *next; unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); - debugfs_remove_recursive(brd_debugfs_dir); - - list_for_each_entry_safe(brd, next, &brd_devices, brd_list) - brd_del_one(brd); + brd_cleanup(); pr_info("brd: module unloaded\n"); } -- cgit v1.2.3