kernel/drivers/nvme/target/fc.c, branch linux-6.9.y

nvmet-fc: Remove __counted_by from nvmet_fc_tgt_queue.fod[]

2024-07-05T07:38:12Z

commit 440e2051c577896275c0e0513ec26964e04c7810 upstream. Work for __counted_by on generic pointers in structures (not just flexible array members) has started landing in Clang 19 (current tip of tree). During the development of this feature, a restriction was added to __counted_by to prevent the flexible array member's element type from including a flexible array member itself such as: struct foo { int count; char buf[]; }; struct bar { int count; struct foo data[] __counted_by(count); }; because the size of data cannot be calculated with the standard array size formula: sizeof(struct foo) * count This restriction was downgraded to a warning but due to CONFIG_WERROR, it can still break the build. The application of __counted_by on the fod member of 'struct nvmet_fc_tgt_queue' triggers this restriction, resulting in: drivers/nvme/target/fc.c:151:2: error: 'counted_by' should not be applied to an array with element of unknown size because 'struct nvmet_fc_fcp_iod' is a struct type with a flexible array member. This will be an error in a future compiler version [-Werror,-Wbounds-safety-counted-by-elt-type-unknown-size] 151 | struct nvmet_fc_fcp_iod fod[] __counted_by(sqsize); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. Remove this use of __counted_by to fix the warning/error. However, rather than remove it altogether, leave it commented, as it may be possible to support this in future compiler releases. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2027 Fixes: ccd3129aca28 ("nvmet-fc: Annotate struct nvmet_fc_tgt_queue with __counted_by") Signed-off-by: Nathan Chancellor Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman

nvmet-fc: move RCU read lock to nvmet_fc_assoc_exists

2024-04-04T15:47:56Z

The RCU lock is only needed for the lookup loop and not for list_ad_tail_rcu call. Thus move it down the call chain into nvmet_fc_assoc_exists. While at it also fix the name typo of the function. Signed-off-by: Daniel Wagner Reviewed-by: Hannes Reinecke Signed-off-by: Keith Busch

nvmet-fc: use RCU list iterator for assoc_list

2024-02-01T15:44:52Z

The assoc_list is a RCU protected list, thus use the RCU flavor of list functions. Let's use this opportunity and refactor this code and move the lookup into a helper and give it a descriptive name. Signed-off-by: Daniel Wagner Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch

nvmet-fc: take ref count on tgtport before delete assoc

2024-02-01T15:44:52Z

We have to ensure that the tgtport is not going away before be have remove all the associations. Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

nvmet-fc: avoid deadlock on delete association path

2024-02-01T15:44:52Z

When deleting an association the shutdown path is deadlocking because we try to flush the nvmet_wq nested. Avoid this by deadlock by deferring the put work into its own work item. Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

nvmet-fc: abort command when there is no binding

2024-02-01T15:44:51Z

When the target port has not active port binding, there is no point in trying to process the command as it has to fail anyway. Instead adding checks to all commands abort the command early. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

nvmet-fc: do not tack refs on tgtports from assoc

2024-02-01T15:44:51Z

The association life time is tied to the life time of the target port. That means we should not take extra a refcount when creating a association. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

nvmet-fc: remove null hostport pointer check

2024-02-01T15:44:51Z

An association has always a valid hostport pointer. Remove useless null pointer check. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

nvmet-fc: hold reference on hostport match

2024-02-01T15:44:51Z

The hostport data structure is shared between the association, this why we keep track of the users via a refcount. So we should not decrement the refcount on a match and free the hostport several times. Reported by KASAN. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

nvmet-fc: free queue and assoc directly

2024-02-01T15:44:51Z

Neither struct nvmet_fc_tgt_queue nor struct nvmet_fc_tgt_assoc are data structure which are used in a RCU context. So there is no reason to delay the free operation. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch