Details
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Improvement
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Resolution: Unresolved
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Minor
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None
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None
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9223372036854775807
Description
It came up in a discussion today on IRC that Lustre-staging was using iov_iter_for_each_range(), which Al Viro apparently added specifically for use by ksocknal_lib_recv() to clean up the code there.
This was done in upstream kernel commits:
- v4.14-rc4-19-g6d1ff4d6f37d "lnet_return_rx_credits_locked: don't abuse list_entry"
- v4.14-rc4-20-g09cf698a5942 "new primitive: iov_iter_for_each_range()"
- v4.14-rc4-23-g33ec9c5cae25 "lustre: switch struct ksock_conn to iov_iter"
- v4.14-rc4-24-g8ececffa12f5 "switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range()"
It isn't clear why these changes weren't part of the patches being merged into master, but they look like a reasonable cleanup (remove a few hundred lines of code in total).
Since the iov_iter_for_each_range() is only available starting in 4.14 (it isn't in RHEL7.x), (and may be on the verge of being removed upstream, based on the IRC discussion) it makes sense to have a configure check and compat version of iov_iter_for_each_range() for kernels that do not provide it, and we can reintroduce it (if needed) when Lustre is pushed upstream.
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| Description |
Original:
It came up in a discussion today on IRC that Lustre-staging was using {{iov_iter_for_each_range()}}, which Al Viro apparently added specifically for use by {{ksocknal_lib_recv()}} to clean up the code there.
This was done in upstream kernel commits: - v4.14-rc4-20-g09cf698a5942 "{{new primitive: iov_iter_for_each_range()}}" - v4.14-rc4-24-g8ececffa12f5 "{{switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range()}}" It isn't clear why these changes weren't part of the patches being merged into master. Since the {{iov_iter_for_each_range()}} is only available starting in 4.14 (it isn't in RHEL7.x), (and appears to be on the verge of being removed upstream, based on the IRC discussion) it makes sense to have a configure check and compat version of {{iov_iter_for_each_range()}} for kernels that do not provide it, and we can reintroduce it (if needed) when Lustre is pushed upstream. |
New:
It came up in a discussion today on IRC that Lustre-staging was using {{iov_iter_for_each_range()}}, which Al Viro apparently added specifically for use by {{ksocknal_lib_recv()}} to clean up the code there.
This was done in upstream kernel commits: - v4.14-rc4-19-g6d1ff4d6f37d "{{lnet_return_rx_credits_locked: don't abuse list_entry}}" - v4.14-rc4-20-g09cf698a5942 "{{new primitive: iov_iter_for_each_range()}}" - v4.14-rc4-23-g33ec9c5cae25 "{{lustre: switch struct ksock_conn to iov_iter}}" - v4.14-rc4-24-g8ececffa12f5 "{{switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range()}}" It isn't clear why these changes weren't part of the patches being merged into master, but they look like a reasonable cleanup (remove a few hundred lines of code in total). Since the {{iov_iter_for_each_range()}} is only available starting in 4.14 (it isn't in RHEL7.x), (and may be on the verge of being removed upstream, based on the IRC discussion) it makes sense to have a configure check and compat version of {{iov_iter_for_each_range()}} for kernels that do not provide it, and we can reintroduce it (if needed) when Lustre is pushed upstream. |