Document the newly introduced explicit-open mount option. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx> --- Changes to v1: - Address Randy's comments --- Documentation/filesystems/zonefs.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/filesystems/zonefs.rst b/Documentation/filesystems/zonefs.rst index 6c18bc8ce332..6b213fe9a33e 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. an NVMe Zoned Namespace device) may have limits on +the number of zones that can be active, that is, zones that are in the +implicit open, explicit open or closed conditions. This potential limitation +translates 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 opened 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
