Revision fc9be616bb8f3ed9cf560308f86904f5c06be205 authored by SeongJae Park on 15 July 2022, 22:51:06 UTC, committed by Juergen Gross on 12 August 2022, 10:13:46 UTC
Persistent grants feature can be used only when both backend and the frontend supports the feature. The feature was always supported by 'blkback', but commit aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants") has introduced a parameter for disabling it runtime. To avoid the parameter be updated while being used by 'blkback', the commit caches the parameter into 'vbd->feature_gnt_persistent' in 'xen_vbd_create()', and then check if the guest also supports the feature and finally updates the field in 'connect_ring()'. However, 'connect_ring()' could be called before 'xen_vbd_create()', so later execution of 'xen_vbd_create()' can wrongly overwrite 'true' to 'vbd->feature_gnt_persistent'. As a result, 'blkback' could try to use 'persistent grants' feature even if the guest doesn't support the feature. This commit fixes the issue by moving the parameter value caching to 'xen_blkif_alloc()', which allocates the 'blkif'. Because the struct embeds 'vbd' object, which will be used by 'connect_ring()' later, this should be called before 'connect_ring()' and therefore this should be the right and safe place to do the caching. Fixes: aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants") Cc: <stable@vger.kernel.org> # 5.10.x Signed-off-by: Maximilian Heyne <mheyne@amazon.de> Signed-off-by: SeongJae Park <sj@kernel.org> Reviewed-by: Maximilian Heyne <mheyne@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20220715225108.193398-2-sj@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com>
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arch | ||
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certs | ||
crypto | ||
drivers | ||
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include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
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net | ||
samples | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.9 KB |
.mailmap | -rw-r--r-- | 23.5 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 99.0 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 653.1 KB |
Makefile | -rw-r--r-- | 64.1 KB |
README | -rw-r--r-- | 727 bytes |
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