lwn.git/drivers/vhost/scsi.c, branch standardize-docs

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

2017-07-13T21:27:32+00:00

Pull SCSI target updates from Nicholas Bellinger: "It's been usually busy for summer, with most of the efforts centered around TCMU developments and various target-core + fabric driver bug fixing activities. Not particularly large in terms of LoC, but lots of smaller patches from many different folks. The highlights include: - ibmvscsis logical partition manager support (Michael Cyr + Bryant Ly) - Convert target/iblock WRITE_SAME to blkdev_issue_zeroout (hch + nab) - Add support for TMR percpu LUN reference counting (nab) - Fix a potential deadlock between EXTENDED_COPY and iscsi shutdown (Bart) - Fix COMPARE_AND_WRITE caw_sem leak during se_cmd quiesce (Jiang Yi) - Fix TMCU module removal (Xiubo Li) - Fix iser-target OOPs during login failure (Andrea Righi + Sagi) - Breakup target-core free_device backend driver callback (mnc) - Perform TCMU add/delete/reconfig synchronously (mnc) - Fix TCMU multiple UIO open/close sequences (mnc) - Fix TCMU CHECK_CONDITION sense handling (mnc) - Fix target-core SAM_STAT_BUSY + TASK_SET_FULL handling (mnc + nab) - Introduce TYPE_ZBC support in PSCSI (Damien Le Moal) - Fix possible TCMU memory leak + OOPs when recalculating cmd base size (Xiubo Li + Bryant Ly + Damien Le Moal + mnc) - Add login_keys_workaround attribute for non RFC initiators (Robert LeBlanc + Arun Easi + nab)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (68 commits) iscsi-target: Add login_keys_workaround attribute for non RFC initiators Revert "qla2xxx: Fix incorrect tcm_qla2xxx_free_cmd use during TMR ABORT" tcmu: clean up the code and with one small fix tcmu: Fix possbile memory leak / OOPs when recalculating cmd base size target: export lio pgr/alua support as device attr target: Fix return sense reason in target_scsi3_emulate_pr_out target: Fix cmd size for PR-OUT in passthrough_parse_cdb tcmu: Fix dev_config_store target: pscsi: Introduce TYPE_ZBC support target: Use macro for WRITE_VERIFY_32 operation codes target: fix SAM_STAT_BUSY/TASK_SET_FULL handling target: remove transport_complete pscsi: finish cmd processing from pscsi_req_done tcmu: fix sense handling during completion target: add helper to copy sense to se_cmd buffer target: do not require a transport_complete for SCF_TRANSPORT_TASK_SENSE target: make device_mutex and device_list static tcmu: Fix flushing cmd entry dcache page tcmu: fix multiple uio open/close sequences tcmu: drop configured check in destroy ...

mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic

2017-07-12T23:26:03+00:00

__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Alex Belits Cc: Chris Wilson Cc: Christoph Hellwig Cc: Darrick J. Wong Cc: David Daney Cc: Johannes Weiner Cc: Mel Gorman Cc: NeilBrown Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vhost/scsi: Don't reinvent the wheel but use existing llist API

2017-06-09T06:26:37+00:00

Although llist provides proper APIs, they are not used. Make them used. Signed-off-by: Byungchul Park Acked-by: Nicholas Bellinger Signed-off-by: Nicholas Bellinger

vhost/scsi: silence uninitialized variable warning

2017-01-19T21:46:30+00:00

This is to silence an uninitialized variable warning in debug output. The problem is this line: pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n", head, out, in); If "head == vq->num" is true on the first iteration then "out" and "in" aren't initialized. We handle that a few lines after the printk. I was tempted to just delete the pr_debug() but I decided to just initialize them to zero instead. Also checkpatch.pl complains if variables are declared as just "unsigned" without the "int". Signed-off-by: Dan Carpenter Signed-off-by: Michael S. Tsirkin

vhost: scsi: constify target_core_fabric_ops structures

2017-01-19T21:46:29+00:00

Declare target_core_fabric_ops strucrues as const as they are only passed as an argument to the functions target_register_template and target_unregister_template. The arguments are of type const struct target_core_fabric_ops *, so target_core_fabric_ops structures having this property can be declared const. Done using Coccinelle: @r disable optional_qualifier@ identifier i; position p; @@ static struct target_core_fabric_ops i@p={...}; @ok@ position p; identifier r.i; @@ ( target_register_template(&i@p) | target_unregister_template(&i@p) ) @bad@ position p!={r.p,ok.p}; identifier r.i; @@ i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ +const struct target_core_fabric_ops i; File size before: drivers/vhost/scsi.o text data bss dec hex filename 18063 2985 40 21088 5260 drivers/vhost/scsi.o File size after: drivers/vhost/scsi.o text data bss dec hex filename 18479 2601 40 21120 5280 drivers/vhost/scsi.o Signed-off-by: Bhumika Goyal Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-12-16T18:24:44+00:00

Pull vfs updates from Al Viro: - more ->d_init() stuff (work.dcache) - pathname resolution cleanups (work.namei) - a few missing iov_iter primitives - copy_from_iter_full() and friends. Either copy the full requested amount, advance the iterator and return true, or fail, return false and do _not_ advance the iterator. Quite a few open-coded callers converted (and became more readable and harder to fuck up that way) (work.iov_iter) - several assorted patches, the big one being logfs removal * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: logfs: remove from tree vfs: fix put_compat_statfs64() does not handle errors namei: fold should_follow_link() with the step into not-followed link namei: pass both WALK_GET and WALK_MORE to should_follow_link() namei: invert WALK_PUT logics namei: shift interpretation of LOOKUP_FOLLOW inside should_follow_link() namei: saner calling conventions for mountpoint_last() namei.c: get rid of user_path_parent() switch getfrag callbacks to ..._full() primitives make skb_add_data,{_nocache}() and skb_copy_to_page_nocache() advance only on success [iov_iter] new primitives - copy_from_iter_full() and friends don't open-code file_inode() ceph: switch to use of ->d_init() ceph: unify dentry_operations instances lustre: switch to use of ->d_init()

vhost/scsi: Remove unused but set variable

2016-12-15T22:13:37+00:00

Remove the unused but set variable se_tpg in vhost_scsi_nexus_cb() to fix the following GCC warning when building with 'W=1': drivers/vhost/scsi.c:1752:26: warning: variable ‘se_tpg’ set but not used Signed-off-by: Tobias Klauser Signed-off-by: Michael S. Tsirkin

[iov_iter] new primitives - copy_from_iter_full() and friends

2016-12-05T19:33:36+00:00

copy_from_iter_full(), copy_from_iter_full_nocache() and csum_and_copy_from_iter_full() - counterparts of copy_from_iter() et.al., advancing iterator only in case of successful full copy and returning whether it had been successful or not. Convert some obvious users. *NOTE* - do not blindly assume that something is a good candidate for those unless you are sure that not advancing iov_iter in failure case is the right thing in this case. Anything that does short read/short write kind of stuff (or is in a loop, etc.) is unlikely to be a good one. Signed-off-by: Al Viro

vhost/scsi: fix reuse of &vq->iov[out] in response

2016-08-23T14:16:57+00:00

The address of the iovec &vq->iov[out] is not guaranteed to contain the scsi command's response iovec throughout the lifetime of the command. Rather, it is more likely to contain an iovec from an immediately following command after looping back around to vhost_get_vq_desc(). Pass along the iovec entirely instead. Fixes: 79c14141a487 ("vhost/scsi: Convert completion path to use copy_to_iter") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Coddington Signed-off-by: Michael S. Tsirkin

target: make close_session optional

2016-05-10T08:19:26+00:00

Signed-off-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger