From a7d4dd109eae096eb38cef8a50a9c86335420a98 Mon Sep 17 00:00:00 2001 From: Md Haris Iqbal Date: Thu, 26 Nov 2020 11:47:23 +0100 Subject: [PATCH] block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name [ Upstream commit 64e8a6ece1a5b1fa21316918053d068baeac84af ] For every rnbd_clt_dev, we alloc the pathname and blk_symlink_name statically to NAME_MAX which is 255 bytes. In most of the cases we only need less than 10 bytes, so 500 bytes per block device are wasted. This commit dynamically allocates memory buffer for pathname and blk_symlink_name. Signed-off-by: Md Haris Iqbal Signed-off-by: Jack Wang Reviewed-by: Lutz Pogrell Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/rnbd/rnbd-clt-sysfs.c | 12 ++++++++++-- drivers/block/rnbd/rnbd-clt.c | 14 +++++++++++--- drivers/block/rnbd/rnbd-clt.h | 4 ++-- 3 files changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c index 4f4474eecadb..b53df40c9a97 100644 --- a/drivers/block/rnbd/rnbd-clt-sysfs.c +++ b/drivers/block/rnbd/rnbd-clt-sysfs.c @@ -435,6 +435,7 @@ void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev) */ if (strlen(dev->blk_symlink_name) && try_module_get(THIS_MODULE)) { sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name); + kfree(dev->blk_symlink_name); module_put(THIS_MODULE); } } @@ -487,10 +488,17 @@ static int rnbd_clt_get_path_name(struct rnbd_clt_dev *dev, char *buf, static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev) { struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj; - int ret; + int ret, len; + + len = strlen(dev->pathname) + strlen(dev->sess->sessname) + 2; + dev->blk_symlink_name = kzalloc(len, GFP_KERNEL); + if (!dev->blk_symlink_name) { + rnbd_clt_err(dev, "Failed to allocate memory for blk_symlink_name\n"); + goto out_err; + } ret = rnbd_clt_get_path_name(dev, dev->blk_symlink_name, - sizeof(dev->blk_symlink_name)); + len); if (ret) { rnbd_clt_err(dev, "Failed to get /sys/block symlink path, err: %d\n", ret); diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index 8b2411ccbda9..f180ebf1e11c 100644 --- a/drivers/block/rnbd/rnbd-clt.c +++ b/drivers/block/rnbd/rnbd-clt.c @@ -59,6 +59,7 @@ static void rnbd_clt_put_dev(struct rnbd_clt_dev *dev) ida_simple_remove(&index_ida, dev->clt_device_id); mutex_unlock(&ida_lock); kfree(dev->hw_queues); + kfree(dev->pathname); rnbd_clt_put_sess(dev->sess); mutex_destroy(&dev->lock); kfree(dev); @@ -1381,10 +1382,17 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess, pathname, sess->sessname, ret); goto out_queues; } + + dev->pathname = kzalloc(strlen(pathname) + 1, GFP_KERNEL); + if (!dev->pathname) { + ret = -ENOMEM; + goto out_queues; + } + strlcpy(dev->pathname, pathname, strlen(pathname) + 1); + dev->clt_device_id = ret; dev->sess = sess; dev->access_mode = access_mode; - strlcpy(dev->pathname, pathname, sizeof(dev->pathname)); mutex_init(&dev->lock); refcount_set(&dev->refcount, 1); dev->dev_state = DEV_STATE_INIT; @@ -1413,8 +1421,8 @@ static bool __exists_dev(const char *pathname) list_for_each_entry(sess, &sess_list, list) { mutex_lock(&sess->lock); list_for_each_entry(dev, &sess->devs_list, list) { - if (!strncmp(dev->pathname, pathname, - sizeof(dev->pathname))) { + if (strlen(dev->pathname) == strlen(pathname) && + !strcmp(dev->pathname, pathname)) { found = true; break; } diff --git a/drivers/block/rnbd/rnbd-clt.h b/drivers/block/rnbd/rnbd-clt.h index ed33654aa486..b193d5904050 100644 --- a/drivers/block/rnbd/rnbd-clt.h +++ b/drivers/block/rnbd/rnbd-clt.h @@ -108,7 +108,7 @@ struct rnbd_clt_dev { u32 clt_device_id; struct mutex lock; enum rnbd_clt_dev_state dev_state; - char pathname[NAME_MAX]; + char *pathname; enum rnbd_access_mode access_mode; bool read_only; bool rotational; @@ -126,7 +126,7 @@ struct rnbd_clt_dev { struct list_head list; struct gendisk *gd; struct kobject kobj; - char blk_symlink_name[NAME_MAX]; + char *blk_symlink_name; refcount_t refcount; struct work_struct unmap_on_rmmod_work; }; -- 2.17.1