Revision 1d8504937478fdc2f3ef2174a816fd3302eca882 authored by Sukadev Bhattiprolu on 30 October 2020, 17:07:11 UTC, committed by Jakub Kicinski on 03 November 2020, 00:54:04 UTC
Commit 5a18e1e0c193b introduced the 'failover_pending' state to track the "failover pending window" - where we wait for the partner to become ready (after a transport event) before actually attempting to failover. i.e window is between following two events: a. we get a transport event due to a FAILOVER b. later, we get CRQ_INITIALIZED indicating the partner is ready at which point we schedule a FAILOVER reset. and ->failover_pending is true during this window. If during this window, we attempt to open (or close) a device, we pretend that the operation succeded and let the FAILOVER reset path complete the operation. This is fine, except if the transport event ("a" above) occurs during the open and after open has already checked whether a failover is pending. If that happens, we fail the open, which can cause the boot scripts to leave the interface down requiring administrator to manually bring up the device. This fix "extends" the failover pending window till we are _actually_ ready to perform the failover reset (i.e until after we get the RTNL lock). Since open() holds the RTNL lock, we can be sure that we either finish the open or if the open() fails due to the failover pending window, we can again pretend that open is done and let the failover complete it. We could try and block the open until failover is completed but a) that could still timeout the application and b) Existing code "pretends" that failover occurred "just after" open succeeded, so marks the open successful and lets the failover complete the open. So, mark the open successful even if the transport event occurs before we actually start the open. Fixes: 5a18e1e0c193 ("ibmvnic: Fix failover case for non-redundant configuration") Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com> Acked-by: Dany Madden <drt@linux.ibm.com> Link: https://lore.kernel.org/r/20201030170711.1562994-1-sukadev@linux.ibm.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.cocciconfig | -rw-r--r-- | 59 bytes |
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COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 97.6 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 563.0 KB |
Makefile | -rw-r--r-- | 62.7 KB |
README | -rw-r--r-- | 727 bytes |
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