From 91f4acb2801ce4985483b0fa174bbe995d105417 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Thu, 26 Nov 2020 11:47:17 +0100 Subject: block/rnbd-clt: support mapping two devices with the same name from different servers Previously, we can't map same device name from different sessions due to the limitation of sysfs naming mechanism. root@clt2:~# ls -l /sys/class/rnbd-client/ctl/devices/ total 0 lrwxrwxrwx 1 root 0 Sep 2 16:31 !dev!nullb1 -> ../../../block/rnbd0 We only use the device name in above, which caused device with the same name can't be mapped from another server. To address the issue, the sessname is appended to the node to differentiate where the device comes from. Also, we need to check if the pathname is existed in a specific session instead of search it in global sess_list. Signed-off-by: Guoqing Jiang Signed-off-by: Gioh Kim Signed-off-by: Jack Wang Reviewed-by: Md Haris Iqbal Signed-off-by: Jens Axboe --- drivers/block/rnbd/rnbd-clt-sysfs.c | 4 ++++ drivers/block/rnbd/rnbd-clt.c | 13 ++++++++----- 2 files changed, 12 insertions(+), 5 deletions(-) (limited to 'drivers/block/rnbd') diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c index e7b41ec7cd6a..5d3c3c80dab4 100644 --- a/drivers/block/rnbd/rnbd-clt-sysfs.c +++ b/drivers/block/rnbd/rnbd-clt-sysfs.c @@ -480,6 +480,10 @@ static int rnbd_clt_get_path_name(struct rnbd_clt_dev *dev, char *buf, if (ret >= len) return -ENAMETOOLONG; + ret = snprintf(buf, len, "%s@%s", buf, dev->sess->sessname); + if (ret >= len) + return -ENAMETOOLONG; + return 0; } diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index edefa0761a81..1bb495e50931 100644 --- a/drivers/block/rnbd/rnbd-clt.c +++ b/drivers/block/rnbd/rnbd-clt.c @@ -1410,13 +1410,16 @@ out_alloc: return ERR_PTR(ret); } -static bool __exists_dev(const char *pathname) +static bool __exists_dev(const char *pathname, const char *sessname) { struct rnbd_clt_session *sess; struct rnbd_clt_dev *dev; bool found = false; list_for_each_entry(sess, &sess_list, list) { + if (sessname && strncmp(sess->sessname, sessname, + sizeof(sess->sessname))) + continue; mutex_lock(&sess->lock); list_for_each_entry(dev, &sess->devs_list, list) { if (!strncmp(dev->pathname, pathname, @@ -1433,12 +1436,12 @@ static bool __exists_dev(const char *pathname) return found; } -static bool exists_devpath(const char *pathname) +static bool exists_devpath(const char *pathname, const char *sessname) { bool found; mutex_lock(&sess_lock); - found = __exists_dev(pathname); + found = __exists_dev(pathname, sessname); mutex_unlock(&sess_lock); return found; @@ -1451,7 +1454,7 @@ static bool insert_dev_if_not_exists_devpath(const char *pathname, bool found; mutex_lock(&sess_lock); - found = __exists_dev(pathname); + found = __exists_dev(pathname, sess->sessname); if (!found) { mutex_lock(&sess->lock); list_add_tail(&dev->list, &sess->devs_list); @@ -1481,7 +1484,7 @@ struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname, struct rnbd_clt_dev *dev; int ret; - if (exists_devpath(pathname)) + if (unlikely(exists_devpath(pathname, sessname))) return ERR_PTR(-EEXIST); sess = find_and_get_or_create_sess(sessname, paths, path_cnt, port_nr); -- cgit v1.2.3