linux.git/net/rds/message.c, branch v5.4.64

net/rds: Use ERR_PTR for rds_message_alloc_sgs()

2020-05-20T06:20:27+00:00

commit 7dba92037baf3fa00b4880a31fd532542264994c upstream.

Returning the error code via a 'int *ret' when the function returns a
pointer is very un-kernely and causes gcc 10's static analysis to choke:

net/rds/message.c: In function ‘rds_message_map_pages’:
net/rds/message.c:358:10: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  358 |   return ERR_PTR(ret);

Use a typical ERR_PTR return instead.

Signed-off-by: Jason Gunthorpe 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

rds: use DIV_ROUND_UP instead of ceil

2019-01-07T15:22:36+00:00

Yes indeed, DIV_ROUND_UP is in kernel.h.

Signed-off-by: Jacob Wen 
Signed-off-by: David S. Miller

net/rds: remove user triggered WARN_ON in rds_sendmsg

2018-12-19T18:27:58+00:00

per comment from Leon in rdma mailing list
https://lkml.org/lkml/2018/10/31/312 :

Please don't forget to remove user triggered WARN_ON.
https://lwn.net/Articles/769365/
"Greg Kroah-Hartman raised the problem of core kernel API code that will
use WARN_ON_ONCE() to complain about bad usage; that will not generate
the desired result if WARN_ON_ONCE() is configured to crash the machine.
He was told that the code should just call pr_warn() instead, and that
the called function should return an error in such situations. It was
generally agreed that any WARN_ON() or WARN_ON_ONCE() calls that can be
triggered from user space need to be fixed."

in addition harden rds_sendmsg to detect and overcome issues with
invalid sg count and fail the sendmsg.

Suggested-by: Leon Romanovsky 
Acked-by: Santosh Shilimkar 
Signed-off-by: shamir rabinovitch 
Signed-off-by: David S. Miller

rds: remove trailing whitespace and blank lines

2018-07-24T21:10:42+00:00

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

rds: remove redundant variable 'sg_off'

2018-03-12T15:12:38+00:00

Variable sg_off is assigned a value but it is never read, hence it is
redundant and can be removed.

Cleans up clang warning:
net/rds/message.c:373:2: warning: Value stored to 'sg_off' is never read

Signed-off-by: Colin Ian King 
Acked-by: Sowmini Varadhan 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller

rds: rds_info_from_znotifier() can be static

2018-03-09T02:54:00+00:00

Fixes: 9426bbc6de99 ("rds: use list structure to track information for zerocopy completion notification")
Signed-off-by: Fengguang Wu 
Signed-off-by: David S. Miller

rds: rds_message_zcopy_from_user() can be static

2018-03-09T02:52:20+00:00

Fixes: d40a126b16ea ("rds: refactor zcopy code into rds_message_zcopy_from_user")
Signed-off-by: Fengguang Wu 
Acked-by: Sowmini Varadhan 
Signed-off-by: David S. Miller

rds: use list structure to track information for zerocopy completion notification

2018-03-07T23:05:57+00:00

Commit 401910db4cd4 ("rds: deliver zerocopy completion notification
with data") removes support fo r zerocopy completion notification
on the sk_error_queue, thus we no longer need to track the cookie
information in sk_buff structures.

This commit removes the struct sk_buff_head rs_zcookie_queue by
a simpler list that results in a smaller memory footprint as well
as more efficient memory_allocation time.

Signed-off-by: Sowmini Varadhan 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller

rds: refactor zcopy code into rds_message_zcopy_from_user

2018-03-07T23:05:57+00:00

Move the large block of code predicated on zcopy from
rds_message_copy_from_user into a new function,
rds_message_zcopy_from_user()

Signed-off-by: Sowmini Varadhan 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller

rds: deliver zerocopy completion notification with data

2018-02-27T19:19:11+00:00

This commit is an optimization over commit 01883eda72bd
("rds: support for zcopy completion notification") for PF_RDS sockets.

RDS applications are predominantly request-response transactions, so
it is more efficient to reduce the number of system calls and have
zerocopy completion notification delivered as ancillary data on the
POLLIN channel.

Cookies are passed up as ancillary data (at level SOL_RDS) in a
struct rds_zcopy_cookies when the returned value of recvmsg() is
greater than, or equal to, 0. A max of RDS_MAX_ZCOOKIES may be passed
with each message.

This commit removes support for zerocopy completion notification on
MSG_ERRQUEUE for PF_RDS sockets.

Signed-off-by: Sowmini Varadhan 
Acked-by: Willem de Bruijn 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller