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Fix unchecked return values and unused return values #13920

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merged 1 commit into from
Sep 23, 2022

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ryao
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@ryao ryao commented Sep 18, 2022

Motivation and Context

Coverity complained about unchecked return values and unused values that turned out to be unused return values.

Description

Different approaches were used to handle the different cases.

  • cmd/zdb/zdb.c: VERIFY0 was used since the existing code had no error handling.
  • cmd/zed/agents/zfs_retire.c: We dismiss the return value with (void) because the values are expected to be potentially unset.
  • cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with (void) because the values are expected to be potentially unset.
  • cmd/ztest.c: VERIFY0 was used since we want failures if something goes wrong in ztest.
  • module/zfs/dsl_dir.c: We dismiss the return value with (void) because there is no guarantee that the zap entry will always be there. For example, old pools imported readonly would not have it and we do not want to fail here because of that.
  • module/zfs/zfs_fm.c: fnvlist_add_*() was used since the allocations sleep and thus can never fail.
  • module/zfs/zvol.c: We dismiss the return value with (void) because we do not need it. This matches what is already done in the analogous zfs_replay_write2().

As for unused return values, they were all in places where there was error handling, so logic was added to handle the return values.

How Has This Been Tested?

A build test was done.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Performance enhancement (non-breaking change which improves efficiency)
  • Code cleanup (non-breaking change which makes code smaller or more readable)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
  • Documentation (a change to man pages or other documentation)

Checklist:

@ryao ryao changed the title Fix uncheck return values Fix unchecked return values Sep 18, 2022
@ryao ryao force-pushed the unchecked_ret branch 4 times, most recently from e5a86df to 25de744 Compare September 19, 2022 03:06
@ryao ryao changed the title Fix unchecked return values Fix unchecked return values and unused return values Sep 19, 2022
@behlendorf behlendorf added the Status: Code Review Needed Ready for review and testing label Sep 20, 2022
@ryao ryao marked this pull request as draft September 20, 2022 12:44
@ryao ryao force-pushed the unchecked_ret branch 3 times, most recently from fb49b56 to 788e72c Compare September 20, 2022 14:08
@ryao ryao marked this pull request as ready for review September 20, 2022 14:08
cmd/zdb/zdb.c Outdated Show resolved Hide resolved
@behlendorf
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There's a checkstyle warning introduced by this change which needs to be resolved.

@ryao
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ryao commented Sep 20, 2022

Fixed.

One day, I should integrate checkstyle into the git commit command on my machine so these are caught early.

@ryao ryao force-pushed the unchecked_ret branch 6 times, most recently from d93e549 to ba8615a Compare September 21, 2022 16:20
@ryao
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ryao commented Sep 21, 2022

I have amended this to handle some unchecked return values reported by coverity in the ZTS.

@ryao ryao force-pushed the unchecked_ret branch 2 times, most recently from 329883f to 8535409 Compare September 21, 2022 21:13
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
@behlendorf behlendorf added Status: Accepted Ready to integrate (reviewed, tested) and removed Status: Code Review Needed Ready for review and testing labels Sep 23, 2022
@behlendorf behlendorf merged commit 2a493a4 into openzfs:master Sep 23, 2022
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 28, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 28, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 28, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Oct 1, 2022
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes openzfs#13920
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