Document the newly introduced explicit-open mount option. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> --- Documentation/filesystems/zonefs.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/filesystems/zonefs.rst b/Documentation/filesystems/zonefs.rst index 6c18bc8ce332..ff8bc3634bad 100644 --- a/Documentation/filesystems/zonefs.rst +++ b/Documentation/filesystems/zonefs.rst @@ -326,6 +326,21 @@ discover the amount of data that has been written to the zone. In the case of a read-only zone discovered at run-time, as indicated in the previous section. The size of the zone file is left unchanged from its last updated value. +A zoned block device (e.g. a NVMe Zoned Namespace device) may have +limits on the number of zones that can be active, that is, zones that +are in the the implicit open, explicit open or closed conditions. +This potential limitation translate into a risk for applications to see +write IO errors due to this limit being exceeded if the zone of a file +is not already active when a write request is issued by the user. + +To avoid these potential errors, the "explicit-open" mount option +forces zones to be made active using an open zone command when a file +is open for writing for the first time. If the zone open command +succeeds, the application is then guaranteed that write requests can be +processed. Conversely, the "explicit-open" mount option will result in +a zone close command being issued to the device on the last close() of +a zone file if the zone is not full nor empty. + Zonefs User Space Tools ======================= -- 2.26.2
