kernel/linux.git/net/rds/ib.c, branch v7.0.10

net/rds: Restrict use of RDS/IB to the initial network namespace

2026-05-23T11:08:39+00:00

[ Upstream commit ebf71dd4aff46e8e421d455db3e231ba43d2fa8a ] Prevent using RDS/IB in network namespaces other than the initial one. The existing RDS/IB code will not work properly in non-initial network namespaces. Fixes: d5a8ac28a7ff ("RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than init_net") Reported-by: syzbot+da8e060735ae02c8f3d1@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=da8e060735ae02c8f3d1 Signed-off-by: Greg Jumper Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260408080420.540032-3-achender@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/rds: Optimize rds_ib_laddr_check

2026-05-23T11:08:39+00:00

[ Upstream commit 236f718ac885965fa886440b9898dfae185c9733 ] rds_ib_laddr_check() creates a CM_ID and attempts to bind the address in question to it. This in order to qualify the allegedly local address as a usable IB/RoCE address. In the field, ExaWatcher runs rds-ping to all ports in the fabric from all local ports. This using all active ToS'es. In a full rack system, we have 14 cell servers and eight db servers. Typically, 6 ToS'es are used. This implies 528 rds-ping invocations per ExaWatcher's "RDSinfo" interval. Adding to this, each rds-ping invocation creates eight sockets and binds the local address to them: socket(AF_RDS, SOCK_SEQPACKET, 0) = 3 bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 4 bind(4, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 5 bind(5, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 6 bind(6, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 7 bind(7, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 8 bind(8, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 9 bind(9, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 socket(AF_RDS, SOCK_SEQPACKET, 0) = 10 bind(10, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.36.2")}, 16) = 0 So, at every interval ExaWatcher executes rds-ping's, 4224 CM_IDs are allocated, considering this full-rack system. After the a CM_ID has been allocated, rdma_bind_addr() is called, with the port number being zero. This implies that the CMA will attempt to search for an un-used ephemeral port. Simplified, the algorithm is to start at a random position in the available port space, and then if needed, iterate until an un-used port is found. The book-keeping of used ports uses the idr system, which again uses slab to allocate new struct idr_layer's. The size is 2092 bytes and slab tries to reduce the wasted space. Hence, it chooses an order:3 allocation, for which 15 idr_layer structs will fit and only 1388 bytes are wasted per the 32KiB order:3 chunk. Although this order:3 allocation seems like a good space/speed trade-off, it does not resonate well with how it used by the CMA. The combination of the randomized starting point in the port space (which has close to zero spatial locality) and the close proximity in time of the 4224 invocations of the rds-ping's, creates a memory hog for order:3 allocations. These costly allocations may need reclaims and/or compaction. At worst, they may fail and produce a stack trace such as (from uek4): [] __inc_zone_page_state+0x35/0x40 [] page_add_file_rmap+0x57/0x60 [] remove_migration_pte+0x3f/0x3c0 [ksplice_6cn872bt_vmlinux_new] [] rmap_walk+0xd8/0x340 [] remove_migration_ptes+0x40/0x50 [] migrate_pages+0x3ec/0x890 [] compact_zone+0x32d/0x9a0 [] compact_zone_order+0x6d/0x90 [] try_to_compact_pages+0x102/0x270 [] __alloc_pages_direct_compact+0x46/0x100 [] __alloc_pages_nodemask+0x74b/0xaa0 [] alloc_pages_current+0x91/0x110 [] new_slab+0x38b/0x480 [] __slab_alloc+0x3b7/0x4a0 [ksplice_s0dk66a8_vmlinux_new] [] kmem_cache_alloc+0x1fb/0x250 [] idr_layer_alloc+0x36/0x90 [] idr_get_empty_slot+0x28c/0x3d0 [] idr_alloc+0x4d/0xf0 [] cma_alloc_port+0x4d/0xa0 [rdma_cm] [] rdma_bind_addr+0x2ae/0x5b0 [rdma_cm] [] rds_ib_laddr_check+0x83/0x2c0 [ksplice_6l2xst5i_rds_rdma_new] [] rds_trans_get_preferred+0x5b/0xa0 [rds] [] rds_bind+0x212/0x280 [rds] [] SYSC_bind+0xe6/0x120 [] SyS_bind+0xe/0x10 [] system_call_fastpath+0x18/0xd4 To avoid these excessive calls to rdma_bind_addr(), we optimize rds_ib_laddr_check() by simply checking if the address in question has been used before. The rds_rdma module keeps track of addresses associated with IB devices, and the function rds_ib_get_device() is used to determine if the address already has been qualified as a valid local address. If not found, we call the legacy rds_ib_laddr_check(), now renamed to rds_ib_laddr_check_cm(). Signed-off-by: Håkon Bugge Signed-off-by: Somasundaram Krishnasamy Signed-off-by: Gerd Rausch Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260408080420.540032-2-achender@kernel.org Signed-off-by: Jakub Kicinski Stable-dep-of: ebf71dd4aff4 ("net/rds: Restrict use of RDS/IB to the initial network namespace") Signed-off-by: Sasha Levin

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

RDMA: Split kernel-only global device caps from uverbs device caps

2022-04-06T18:02:13+00:00

Split out flags from ib_device::device_cap_flags that are only used internally to the kernel into kernel_cap_flags that is not part of the uapi. This limits the device_cap_flags to being the same bitmap that will be copied to userspace. This cleanly splits out the uverbs flags from the kernel flags to avoid confusion in the flags bitmap. Add some short comments describing which each of the kernel flags is connected to. Remove unused kernel flags. Link: https://lore.kernel.org/r/0-v2-22c19e565eef+139a-kern_caps_jgg@nvidia.com Reviewed-by: Christoph Hellwig Reviewed-by: Max Gurtovoy Signed-off-by: Jason Gunthorpe

rds: stop using dmapool

2020-11-17T19:22:06+00:00

RDMA ULPs should only perform DMA through the ib_dma_* API instead of using the hidden dma_device directly. In addition using the dma coherent API family that dmapool is a part of can be very ineffcient on plaforms that are not DMA coherent. Switch to use slab allocations and the ib_dma_* APIs instead. Link: https://lore.kernel.org/r/20201106181941.1878556-6-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Santosh Shilimkar Signed-off-by: Jason Gunthorpe

RDMA: Remove 'max_fmr'

2020-06-02T23:32:54+00:00

Now that FMR support is gone, this attribute can be deleted from all places. Link: https://lore.kernel.org/r/12-v3-f58e6669d5d3+2cf-fmr_removal_jgg@mellanox.com Reviewed-by: Max Gurtovoy Reviewed-by: Bernard Metzler Signed-off-by: Jason Gunthorpe

RDMA/rds: Remove FMR support for memory registration

2020-06-02T23:32:53+00:00

Use FRWR method for memory registration by default and remove the ancient and unsafe FMR method. Link: https://lore.kernel.org/r/3-v3-f58e6669d5d3+2cf-fmr_removal_jgg@mellanox.com Signed-off-by: Max Gurtovoy Signed-off-by: Jason Gunthorpe

RDMA: Allow ib_client's to fail when add() is called

2020-05-06T14:57:33+00:00

When a client is added it isn't allowed to fail, but all the client's have various failure paths within their add routines. This creates the very fringe condition where the client was added, failed during add and didn't set the client_data. The core code will then still call other client_data centric ops like remove(), rename(), get_nl_info(), and get_net_dev_by_params() with NULL client_data - which is confusing and unexpected. If the add() callback fails, then do not call any more client ops for the device, even remove. Remove all the now redundant checks for NULL client_data in ops callbacks. Update all the add() callbacks to return error codes appropriately. EOPNOTSUPP is used for cases where the ULP does not support the ib_device - eg because it only works with IB. Link: https://lore.kernel.org/r/20200421172440.387069-1-leon@kernel.org Signed-off-by: Leon Romanovsky Acked-by: Ursula Braun Signed-off-by: Jason Gunthorpe

net/rds: Handle ODP mr registration/unregistration

2020-01-18T09:48:19+00:00

On-Demand-Paging MRs are registered using ib_reg_user_mr and unregistered with ib_dereg_mr. Signed-off-by: Hans Westgaard Ry Acked-by: Santosh Shilimkar Signed-off-by: Leon Romanovsky