Cleanup: Address Clang's static analyzer's unused code complaints #13986
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These were categorized as the following: * Dead assignment 23 * Dead increment 4 * Dead initialization 6 * Dead nested assignment 18 Most of these are harmless, but since actual issues can hide among them, we correct them. That said, there were a few return values that were being ignored that appeared to merit some correction: * `destroy_callback()` in `cmd/zfs/zfs_main.c` ignored the error from `destroy_batched()`. We handle it by returning -1 if there is an error. * `zfs_do_upgrade()` in `cmd/zfs/zfs_main.c` ignored the error from `zfs_for_each()`. We handle it by doing a binary OR of the error value from the subsequent `zfs_for_each()` call to the existing value. This is how errors are mostly handled inside `zfs_for_each()`. The error value here is passed to exit from the zfs command, so doing a binary or on it is better than what we did previously. * `get_zap_prop()` in `module/zfs/zcp_get.c` ignored the error from `dsl_prop_get_ds()` when the property is not of type string. We return an error when it does. There is a small concern that the `zfs_get_temporary_prop()` call would handle things, but in the case that it does not, we would be pushing an uninitialized numval onto the lua stack. It is expected that `dsl_prop_get_ds()` will succeed anytime that `zfs_get_temporary_prop()` does, so that not giving it a chance to fix things is not a problem. * `draid_merge_impl()` in `tests/zfs-tests/cmd/draid.c` used `nvlist_add_nvlist()` twice in ways in which errors are expected to be impossible, so we switch to `fnvlist_add_nvlist()`. A few notable ones did not merit use of the return value, so we suppressed it with `(void)`: * `write_free_diffs()` in `lib/libzfs/libzfs_diff.c` ignored the error value from `describe_free()`. A look through the commit history revealed that this was intentional. * `arc_evict_hdr()` in `module/zfs/arc.c` did not need to use the returned handle from `arc_hdr_realloc()` because it is already referenced in lists. * `spa_vdev_detach()` in `module/zfs/spa.c` has a comment explicitly saying not to use the error from `vdev_label_init()` because whatever causes the error could be the reason why a detach is being done. Unfortunately, I am not presently able to analyze the kernel modules with Clang's static analyzer, so I could have missed some cases of this. In cases where reports were present in code that is duplicated between Linux and FreeBSD, I made a conscious effort to fix the FreeBSD version too. After this commit is merged, regressions like dee8934 should become extremely obvious with Clang's static analyzer since a regression would appear in the results as the only instance of unused code. That assumes that Coverity does not catch the issue first. My local branch with fixes from all of my outstanding non-draft pull requests shows 118 reports from Clang's static anlayzer after this patch. That is down by 51 from 169. Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
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Hey @ryao - just wanted to say thanks for poring over all the static analyzer output. It can be tiring and thankless but it really improves quality and is appreciated - cheers. |
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* etc: mask zfs-load-key.service Otherwise, systemd-sysv-generator will generate a service equivalent that breaks the boot: under systemd this is covered by zfs-mount-generator We already do this for zfs-import.service, and other init scripts are suppressed automatically by the "actual" .service files Fixes: commit f04b976 ("Add init script to load keys") Reviewed-by: George Melikov <mail@gmelikov.ru> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz> Closes openzfs#14010 Closes openzfs#14019 * Linux: Remove ZFS_AC_KERNEL_SRC_MODULE_PARAM_CALL_CONST autotools check On older kernels, the definition for `module_param_call()` typecasts function pointers to `(void *)`, which triggers -Werror, causing the check to return false when it should return true. Fixing this breaks the build process on some older kernels because they define a `__check_old_set_param()` function in their headers that checks for a non-constified `->set()`. We workaround that through the c preprocessor by defining `__check_old_set_param(set)` to `(set)`, which prevents the build failures. However, it is now apparent that all kernels that we support have adopted the GRSecurity change, so there is no need to have an explicit autotools check for it anymore. We therefore remove the autotools check, while adding the workaround to our headers for the build time non-constified `->set()` check done by older kernel headers. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Jorgen Lundman <lundman@lundman.net> Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#13984 Closes openzfs#14004 * Cleanup: 64-bit kernel module parameters should use fixed width types Various module parameters such as `zfs_arc_max` were originally `uint64_t` on OpenSolaris/Illumos, but were changed to `unsigned long` for Linux compatibility because Linux's kernel default module parameter implementation did not support 64-bit types on 32-bit platforms. This caused problems when porting OpenZFS to Windows because its LLP64 memory model made `unsigned long` a 32-bit type on 64-bit, which created the undesireable situation that parameters that should accept 64-bit values could not on 64-bit Windows. Upon inspection, it turns out that the Linux kernel module parameter interface is extensible, such that we are allowed to define our own types. Rather than maintaining the original type change via hacks to to continue shrinking module parameters on 32-bit Linux, we implement support for 64-bit module parameters on Linux. After doing a review of all 64-bit kernel parameters (found via the man page and also proposed changes by Andrew Innes), the kernel module parameters fell into a few groups: Parameters that were originally 64-bit on Illumos: * dbuf_cache_max_bytes * dbuf_metadata_cache_max_bytes * l2arc_feed_min_ms * l2arc_feed_secs * l2arc_headroom * l2arc_headroom_boost * l2arc_write_boost * l2arc_write_max * metaslab_aliquot * metaslab_force_ganging * zfetch_array_rd_sz * zfs_arc_max * zfs_arc_meta_limit * zfs_arc_meta_min * zfs_arc_min * zfs_async_block_max_blocks * zfs_condense_max_obsolete_bytes * zfs_condense_min_mapping_bytes * zfs_deadman_checktime_ms * zfs_deadman_synctime_ms * zfs_initialize_chunk_size * zfs_initialize_value * zfs_lua_max_instrlimit * zfs_lua_max_memlimit * zil_slog_bulk Parameters that were originally 32-bit on Illumos: * zfs_per_txg_dirty_frees_percent Parameters that were originally `ssize_t` on Illumos: * zfs_immediate_write_sz Note that `ssize_t` is `int32_t` on 32-bit and `int64_t` on 64-bit. It has been upgraded to 64-bit. Parameters that were `long`/`unsigned long` because of Linux/FreeBSD influence: * l2arc_rebuild_blocks_min_l2size * zfs_key_max_salt_uses * zfs_max_log_walking * zfs_max_logsm_summary_length * zfs_metaslab_max_size_cache_sec * zfs_min_metaslabs_to_flush * zfs_multihost_interval * zfs_unflushed_log_block_max * zfs_unflushed_log_block_min * zfs_unflushed_log_block_pct * zfs_unflushed_max_mem_amt * zfs_unflushed_max_mem_ppm New parameters that do not exist in Illumos: * l2arc_trim_ahead * vdev_file_logical_ashift * vdev_file_physical_ashift * zfs_arc_dnode_limit * zfs_arc_dnode_limit_percent * zfs_arc_dnode_reduce_percent * zfs_arc_meta_limit_percent * zfs_arc_sys_free * zfs_deadman_ziotime_ms * zfs_delete_blocks * zfs_history_output_max * zfs_livelist_max_entries * zfs_max_async_dedup_frees * zfs_max_nvlist_src_size * zfs_rebuild_max_segment * zfs_rebuild_vdev_limit * zfs_unflushed_log_txg_max * zfs_vdev_max_auto_ashift * zfs_vdev_min_auto_ashift * zfs_vnops_read_chunk_size * zvol_max_discard_blocks Rather than clutter the lists with commentary, the module parameters that need comments are repeated below. A few parameters were defined in Linux/FreeBSD specific code, where the use of ulong/long is not an issue for portability, so we leave them alone: * zfs_delete_blocks * zfs_key_max_salt_uses * zvol_max_discard_blocks The documentation for a few parameters was found to be incorrect: * zfs_deadman_checktime_ms - incorrectly documented as int * zfs_delete_blocks - not documented as Linux only * zfs_history_output_max - incorrectly documented as int * zfs_vnops_read_chunk_size - incorrectly documented as long * zvol_max_discard_blocks - incorrectly documented as ulong The documentation for these has been fixed, alongside the changes to document the switch to fixed width types. In addition, several kernel module parameters were percentages or held ashift values, so being 64-bit never made sense for them. They have been downgraded to 32-bit: * vdev_file_logical_ashift * vdev_file_physical_ashift * zfs_arc_dnode_limit_percent * zfs_arc_dnode_reduce_percent * zfs_arc_meta_limit_percent * zfs_per_txg_dirty_frees_percent * zfs_unflushed_log_block_pct * zfs_vdev_max_auto_ashift * zfs_vdev_min_auto_ashift Of special note are `zfs_vdev_max_auto_ashift` and `zfs_vdev_min_auto_ashift`, which were already defined as `uint64_t`, and passed to the kernel as `ulong`. This is inherently buggy on big endian 32-bit Linux, since the values would not be written to the correct locations. 32-bit FreeBSD was unaffected because its sysctl code correctly treated this as a `uint64_t`. Lastly, a code comment suggests that `zfs_arc_sys_free` is Linux-specific, but there is nothing to indicate to me that it is Linux-specific. Nothing was done about that. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Jorgen Lundman <lundman@lundman.net> Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Original-patch-by: Andrew Innes <andrew.c12@gmail.com> Original-patch-by: Jorgen Lundman <lundman@lundman.net> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#13984 Closes openzfs#14004 * cstyle: Allow URLs in C++ comments If a C++ comment contained a URL, the `://` part of the URL would trigger an error because there was no trailing blank, but trailing blanks make for an invalid URL. Modify the check to ignore text within the C++ comment. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chris Lindee <chris.lindee+github@gmail.com> Closes openzfs#13987 * zfs_domount: fix double-disown of dataset / double-free of zfsvfs_t Before this patch, in zfs_domount, if zfs_root or d_make_root fails, we leave zfsvfs != NULL. This will lead to execution of the error handling `if` statement at the `out` label, and hence to a call to dmu_objset_disown and zfsvfs_free. However, zfs_umount, which we call upon failure of zfs_root and d_make_root already does dmu_objset_disown and zfsvfs_free. I suppose this patch rather adds to the brittleness of this part of the code base, but I don't want to invest more time in this right now. To add a regression test, we'd need some kind of fault injection facility for zfs_root or d_make_root, which doesn't exist right now. And even then, I think that regression test would be too closely tied to the implementation. To repro the double-disown / double-free, do the following: 1. patch zfs_root to always return an error 2. mount a ZFS filesystem Here's the stack trace you would see then: VERIFY3(ds->ds_owner == tag) failed (0000000000000000 == ffff9142361e8000) PANIC at dsl_dataset.c:1003:dsl_dataset_disown() Showing stack for process 28332 CPU: 2 PID: 28332 Comm: zpool Tainted: G O 5.10.103-1.nutanix.el7.x86_64 #1 Call Trace: dump_stack+0x74/0x92 spl_dumpstack+0x29/0x2b [spl] spl_panic+0xd4/0xfc [spl] dsl_dataset_disown+0xe9/0x150 [zfs] dmu_objset_disown+0xd6/0x150 [zfs] zfs_domount+0x17b/0x4b0 [zfs] zpl_mount+0x174/0x220 [zfs] legacy_get_tree+0x2b/0x50 vfs_get_tree+0x2a/0xc0 path_mount+0x2fa/0xa70 do_mount+0x7c/0xa0 __x64_sys_mount+0x8b/0xe0 do_syscall_64+0x38/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Co-authored-by: Christian Schwarz <christian.schwarz@nutanix.com> Signed-off-by: Christian Schwarz <christian.schwarz@nutanix.com> Closes openzfs#14025 * Fix potential NULL pointer dereference in lzc_ioctl() Users are allowed to pass NULL to resultp, but we unconditionally assume that they never do. When an external user does pass NULL to resultp, we dereference a NULL pointer. Clang's static analyzer complained about this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14008 * Cleanup: Address Clang's static analyzer's unused code complaints These were categorized as the following: * Dead assignment 23 * Dead increment 4 * Dead initialization 6 * Dead nested assignment 18 Most of these are harmless, but since actual issues can hide among them, we correct them. That said, there were a few return values that were being ignored that appeared to merit some correction: * `destroy_callback()` in `cmd/zfs/zfs_main.c` ignored the error from `destroy_batched()`. We handle it by returning -1 if there is an error. * `zfs_do_upgrade()` in `cmd/zfs/zfs_main.c` ignored the error from `zfs_for_each()`. We handle it by doing a binary OR of the error value from the subsequent `zfs_for_each()` call to the existing value. This is how errors are mostly handled inside `zfs_for_each()`. The error value here is passed to exit from the zfs command, so doing a binary or on it is better than what we did previously. * `get_zap_prop()` in `module/zfs/zcp_get.c` ignored the error from `dsl_prop_get_ds()` when the property is not of type string. We return an error when it does. There is a small concern that the `zfs_get_temporary_prop()` call would handle things, but in the case that it does not, we would be pushing an uninitialized numval onto the lua stack. It is expected that `dsl_prop_get_ds()` will succeed anytime that `zfs_get_temporary_prop()` does, so that not giving it a chance to fix things is not a problem. * `draid_merge_impl()` in `tests/zfs-tests/cmd/draid.c` used `nvlist_add_nvlist()` twice in ways in which errors are expected to be impossible, so we switch to `fnvlist_add_nvlist()`. A few notable ones did not merit use of the return value, so we suppressed it with `(void)`: * `write_free_diffs()` in `lib/libzfs/libzfs_diff.c` ignored the error value from `describe_free()`. A look through the commit history revealed that this was intentional. * `arc_evict_hdr()` in `module/zfs/arc.c` did not need to use the returned handle from `arc_hdr_realloc()` because it is already referenced in lists. * `spa_vdev_detach()` in `module/zfs/spa.c` has a comment explicitly saying not to use the error from `vdev_label_init()` because whatever causes the error could be the reason why a detach is being done. Unfortunately, I am not presently able to analyze the kernel modules with Clang's static analyzer, so I could have missed some cases of this. In cases where reports were present in code that is duplicated between Linux and FreeBSD, I made a conscious effort to fix the FreeBSD version too. After this commit is merged, regressions like dee8934 should become extremely obvious with Clang's static analyzer since a regression would appear in the results as the only instance of unused code. That assumes that Coverity does not catch the issue first. My local branch with fixes from all of my outstanding non-draft pull requests shows 118 reports from Clang's static anlayzer after this patch. That is down by 51 from 169. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Cedric Berger <cedric@precidata.com> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#13986 * zstream: allow decompress to fix metadata for uncompressed records If a record is uncompressed on-disk but the block pointer insists otherwise, reading it will return EIO. This commit adds an "off" type to the "zstream decompress" command. Using it will set the compression field in a zfs stream to "off" without changing the record's data. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: George Melikov <mail@gmelikov.ru> Signed-off-by: Alan Somers <asomers@FreeBSD.org> Sponsored by: Axcient Closes openzfs#13997 * Fix theoretical array overflow in lua_typename() Out of the 12 defects in lua that coverity reports, 5 of them involve `lua_typename()` and out of the dozens of defects in ZFS that lua reports, 3 of them involve `lua_typename()` due to the ZCP code. Given all of the uses of `lua_typename()` in the ZCP code, I was surprised that there were not more. It appears that only 2 were reported because only 3 called `lua_type()`, which does a defective sanity check that allows invalid types to be passed. lua/lua@d4fb848 addressed this in upstream lua 5.3. Unfortunately, we did not get that fix since we use lua 5.2 and we do not have assertions enabled in lua, so the upstream solution would not do anything. While we could adopt the upstream solution and enable assertions, a simpler solution is to fix the issue by making `lua_typename()` return `internal_type_error` whenever it is called with an invalid type. This avoids the array overflow and if we ever see it appear somewhere, we will know there is a problem with the lua interpreter. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#13947 * Linux compat: fix DECLARE_EVENT_CLASS() test when ZFS is built-in ZFS_LINUX_TRY_COMPILE_HEADER macro doesn't take CONFIG_ZFS=y into account. As a result, on several latest Linux versions, configure script marks DECLARE_EVENT_CLASS() available for non-GPL when ZFS is being built as a module, but marks it unavailable when ZFS is built-in. Follow the logic of the neighbor macros and adjust ZFS_LINUX_TRY_COMPILE_HEADER accordingly, so that it doesn't try to look for a .ko when ZFS is built-in. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Signed-off-by: Alexander Lobakin <alobakin@pm.me> Closes openzfs#14006 * Fix declarations of non-global variables This patch inserts the `static` keyword to non-global variables, which where found by the analysis tool smatch. Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de> Closes openzfs#13970 * Coverity model file update Upon review, it was found that the model for malloc() was incorrect. In addition, several general purpose memory allocation functions were missing models: * kmem_vasprintf() * kmem_asprintf() * kmem_strdup() * kmem_strfree() * spl_vmem_alloc() * spl_vmem_zalloc() * spl_vmem_free() * calloc() As an experiment to try to find more bugs, some less than general purpose memory allocation functions were also given models: * zfsvfs_create() * zfsvfs_free() * nvlist_alloc() * nvlist_dup() * nvlist_free() * nvlist_pack() * nvlist_unpack() Finally, the models were improved using additional coverity primitives: * __coverity_negative_sink__() * __coverity_writeall0__() * __coverity_mark_as_uninitialized_buffer__() * __coverity_mark_as_afm_allocated__() In addition, an attempt to inform coverity that certain modelled functions read entire buffers was used by adding the following to certain models: int first = buf[0]; int last = buf[buflen-1]; It was inspired by the QEMU model file. No additional false positives were found by this, but it is believed that the more accurate model file will help to catch false positives in the future. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14048 * Linux 6.1 compat: change order of sys/mutex.h includes After Linux 6.1-rc1 came out, the build started failing to build a couple of the files in the linux spl code due to the mutex_init redefinition. Moving the sys/mutex.h include to a lower position within these two files appears to fix the problem. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Coleman Kane <ckane@colemankane.org> Closes openzfs#14040 * ZED: Fix uninitialized value reads Coverity complained about a couple of uninitialized value reads in ZED. * zfs_deliver_dle() can pass an uninitialized string to zed_log_msg() * An uninitialized sev.sigev_signo is passed to timer_create() The former would log garbage while the latter is not a real issue, but we might as well suppress it by initializing the field to 0 for consistency's sake. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14047 * Fix NULL pointer dereference in zdb Clang's static analyzer complained that we dereference a NULL pointer in dump_path() if we return 0 when there is an error. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14044 * fm_fmri_hc_create() must call va_end() before returning clang-tidy caught this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14044 * Fix NULL pointer passed to strlcpy from zap_lookup_impl() Clang's static analyzer pointed out that whenever zap_lookup_by_dnode() is called, we have the following stack where strlcpy() is passed a NULL pointer for realname from zap_lookup_by_dnode(): strlcpy() zap_lookup_impl() zap_lookup_norm_by_dnode() zap_lookup_by_dnode() Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14044 * Fix NULL pointer dereference in spa_open_common() Calling spa_open() will pass a NULL pointer to spa_open_common()'s config parameter. Under the right circumstances, we will dereference the config parameter without doing a NULL check. Clang's static analyzer found this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14044 * set_global_var() should not pass NULL pointers to dlclose() Both Coverity and Clang's static analyzer caught this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14044 * Fix possible NULL pointer dereference in sha2_mac_init() If mechanism->cm_param is NULL, passing mechanism to PROV_SHA2_GET_DIGEST_LEN() will dereference a NULL pointer. Coverity reported this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14044 * Cleanup: Simplify userspace abd_free_chunks() Clang's static analyzer complained that we could use after free here if the inner loop ever iterated. That is a false positive, but upon inspection, the userland abd_alloc_chunks() function never will put multiple consecutive pages into a `struct scatterlist`, so there is no need to loop. We delete the inner loop. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14042 * Cleanup: Delete unnecessary pointer check from vdev_to_nvlist_iter() This confused Clang's static analyzer, making it think there was a possible NULL pointer dereference. There is no NULL pointer dereference. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14042 * Cleanup: metaslab_alloc_dva() should not NULL check mg->mg_next This is a circularly linked list. mg->mg_next can never be NULL. This caused 3 defect reports in Coverity. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14042 * Cleanup: zvol_add_clones() should not NULL check dp It is never NULL because we return early if dsl_pool_hold() fails. This caused Coverity to complain. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14042 * Cleanup: Delete dead code from send_merge_thread() range is always deferenced before it reaches this check, such that the kmem_zalloc() call is never executed. There is also no need to set `range->eos_marker = B_TRUE` because it is already set. Coverity incorrectly complained about a potential NULL pointer dereference because of this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14042 * Cleanup: Remove NULL pointer check from dmu_send_impl() The pointer is to a structure member, so it is never NULL. Coverity complained about this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14042 * Fix memory leaks in dmu_send()/dmu_send_obj() If we encounter an EXDEV error when using the redacted snapshots feature, the memory used by dspp.fromredactsnaps is leaked. Clang's static analyzer caught this during an experiment in which I had annotated various headers in an attempt to improve the results of static analysis. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#13973 * Support idmapped mount Adds support for idmapped mounts. Supported as of Linux 5.12 this functionality allows user and group IDs to be remapped without changing their state on disk. This can be useful for portable home directories and a variety of container related use cases. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Signed-off-by: Youzhong Yang <yyang@mathworks.com> Closes openzfs#12923 Closes openzfs#13671 * Fix sequential resilver drive failure race condition This patch handles the race condition on simultaneous failure of 2 drives, which misses the vdev_rebuild_reset_wanted signal in vdev_rebuild_thread. We retry to catch this inside the vdev_rebuild_complete_sync function. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com> Reviewed-by: Akash B <akash-b@hpe.com> Signed-off-by: Samuel Wycliffe J <samwyc@hpe.com> Closes openzfs#14041 Closes openzfs#14050 * Add options to zfs redundant_metadata property Currently, additional/extra copies are created for metadata in addition to the redundancy provided by the pool(mirror/raidz/draid), due to this 2 times more space is utilized per inode and this decreases the total number of inodes that can be created in the filesystem. By setting redundant_metadata to none, no additional copies of metadata are created, hence can reduce the space consumed by the additional metadata copies and increase the total number of inodes that can be created in the filesystem. Additionally, this can improve file create performance due to the reduced amount of metadata which needs to be written. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com> Signed-off-by: Akash B <akash-b@hpe.com> Closes openzfs#13680 * Fix userland memory leak in zfs_do_send() Clang 15's static analyzer caught this. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14045 * Fix theoretical use of uninitialized values Clang's static analyzer complains about this. In get_configs(), if we have an invalid configuration that has no top level vdevs, we can read a couple of uninitialized variables. Aborting upon seeing this would break the userland tools for healthy pools, so we instead initialize the two variables to 0 to allow the userland tools to continue functioning for the pools with valid configurations. In zfs_do_wait(), if no wait activities are enabled, we read an uninitialized error variable. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14043 * Silence static analyzer warnings about spa_sync_props() Both Coverity and Clang's static analyzer complain about reading an uninitialized intval if the property is not passed as DATA_TYPE_UINT64 in the nvlist. This is impossible becuase spa_prop_validate() already checked this, but they are unlikely to be the last static analyzers to complain about this, so lets just refactor the code to suppress the warnings. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14043 * crypto_get_ptrs() should always write to *out_data_2 Callers will check if it has been set to NULL before trying to access it, but never initialize it themselves. Whenever "one block spans two iovecs", `crypto_get_ptrs()` will return, without ever setting `*out_data_2 = NULL`. The caller will then do a NULL check against the uninitailized pointer and if it is not zero, pass it to `memcpy()`. The only reason this has not caused horrible runtime issues is because `memcpy()` should be told to copy zero bytes when this happens. That said, this is technically undefined behavior, so we should correct it so that future changes to the code cannot trigger it. Clang's static analyzer found this with the help of CodeChecker's CTU analysis. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14043 * abd_return_buf() should call zfs_refcount_remove_many() early Calling zfs_refcount_remove_many() after freeing memory means we pass a reference to freed memory as the holder. This is not believed to be able to cause a problem, but there is a bit of a tradition of fixing these issues when they appear so that they do not obscure more serious issues in static analyzer output, so we fix this one too. Clang's static analyzer found this with the help of CodeChecker's CTU analysis. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14043 * Add defensive assertion to vdev_queue_aggregate() a6ccb36 had been intended to include this to silence Coverity reports, but this one was missed by mistake. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes openzfs#14043 * Fix build failures Co-authored-by: наб <nabijaczleweli@nabijaczleweli.xyz> Co-authored-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Co-authored-by: ColMelvin <chris.lindee+github@gmail.com> Co-authored-by: Christian Schwarz <me@cschwarz.com> Co-authored-by: Alan Somers <asomers@FreeBSD.org> Co-authored-by: Alexander <solbjorn@users.noreply.github.com> Co-authored-by: Tino Reichardt <milky-zfs@mcmilk.de> Co-authored-by: Coleman Kane <ckane@colemankane.org> Co-authored-by: youzhongyang <youzhong@gmail.com> Co-authored-by: samwyc <115969550+samwyc@users.noreply.github.com> Co-authored-by: Akash B <akash-b@hpe.com>
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Motivation and Context
These were categorized as the following:
Dead assignment 23
Dead increment 4
Dead initialization 6
Dead nested assignment 18
Most of these are harmless, but since actual issues can hide among them, we correct them.
After this commit is merged, regressions like dee8934 should become extremely obvious with Clang's static analyzer since a regression would appear in the results as the only instance of unused code. That assumes that Coverity does not catch the issue first.
My local branch with fixes from all of my outstanding non-draft pull requests shows 118 reports from Clang's static anlayzer after this patch. That is down by 51 from 169.
Description
There were a few return values that were being ignored that appeared to merit some correction:
destroy_callback()incmd/zfs/zfs_main.cignored the error fromdestroy_batched(). We handle it by returning -1 if there is an error.zfs_do_upgrade()incmd/zfs/zfs_main.cignored the error fromzfs_for_each(). We handle it by doing a binary OR of the error value from the subsequentzfs_for_each()call to the existing value. This is how errors are mostly handled insidezfs_for_each(). The error value here is passed to exit from the zfs command, so doing a binary or on it is better than what we did previously.get_zap_prop()inmodule/zfs/zcp_get.cignored the error fromdsl_prop_get_ds()when the property is not of type string. We return an error when it does. There is a small concern that thezfs_get_temporary_prop()call would handle things, but in the case that it does not, we would be pushing an uninitialized numval onto the lua stack. It is expected thatdsl_prop_get_ds()will succeed anytime thatzfs_get_temporary_prop()does, so that not giving it a chance to fix things is not a problem.draid_merge_impl()intests/zfs-tests/cmd/draid.cusednvlist_add_nvlist()twice in ways in which errors are expected to be impossible, so we switch tofnvlist_add_nvlist().A few notable ones did not merit use of the return value, so we suppressed it with
(void):write_free_diffs()inlib/libzfs/libzfs_diff.cignored the error value fromdescribe_free(). A look through the commit history revealed that this was intentional.arc_evict_hdr()inmodule/zfs/arc.cdid not need to use the returned handle fromarc_hdr_realloc()because it is already referenced in lists.spa_vdev_detach()inmodule/zfs/spa.chas a comment explicitly saying not to use the error fromvdev_label_init()because whatever causes the error could be the reason why a detach is being done.How Has This Been Tested?
A build test was done. More extensive testing will be done on the buildbot.
Unfortunately, I am not presently able to analyze the kernel modules with Clang's static analyzer, so I could have missed some cases of this.
Types of changes
Checklist:
Signed-off-by.