nvmet: add simple file backed ns support
This patch adds simple file backed namespace support for NVMeOF target.
The new file io-cmd-file.c is responsible for handling the code for I/O
commands when ns is file backed. Also, we introduce mempools based slow
path using sync I/Os for file backed ns to ensure forward progress under
reclaim.
The old block device based implementation is moved to io-cmd-bdev.c and
use a "nvmet_bdev_" symbol prefix. The enable/disable calls are also
move into the respective files.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: updated changelog, fixed double req->ns lookup in bdev case]
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index d1afcfd..b2ba95b 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -45,6 +45,10 @@ static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
return NVME_SC_INVALID_NS;
}
+ /* we don't have the right data for file backed ns */
+ if (!ns->bdev)
+ goto out;
+
host_reads = part_stat_read(ns->bdev->bd_part, ios[READ]);
data_units_read = part_stat_read(ns->bdev->bd_part, sectors[READ]);
host_writes = part_stat_read(ns->bdev->bd_part, ios[WRITE]);
@@ -54,6 +58,7 @@ static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
put_unaligned_le64(host_writes, &slog->host_writes[0]);
put_unaligned_le64(data_units_written, &slog->data_units_written[0]);
+out:
nvmet_put_namespace(ns);
return NVME_SC_SUCCESS;
@@ -71,6 +76,9 @@ static u16 nvmet_get_smart_log_all(struct nvmet_req *req,
rcu_read_lock();
list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
+ /* we don't have the right data for file backed ns */
+ if (!ns->bdev)
+ continue;
host_reads += part_stat_read(ns->bdev->bd_part, ios[READ]);
data_units_read +=
part_stat_read(ns->bdev->bd_part, sectors[READ]);
