CFE-90: reconcile storage mount options when they drift (opt-in remount)#6222
CFE-90: reconcile storage mount options when they drift (opt-in remount)#6222nickanderson wants to merge 5 commits into
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@cf-bottom jenkins please |
- Remove unnecessary NULL guards before free() in DeleteMountInfo(). free(NULL) is a C-standard no-op; bare calls match the surrounding convention (FreeOptionsList, VerifyMount, etc.). - Add assert(a != NULL) to LiveMountConverged, ReconcileMountOptions, FileSystemMountedCorrectly, and VerifyMountPromise to resolve the 15 null-dereference warnings. This follows the existing convention in VerifyInFstab, VerifyMount, and VerifyUnmount which already had these asserts.
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@cf-bottom jenkins please |
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Sure, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14143/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14143/ |
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@cf-bottom jenkins please |
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Sure, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14145/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14145/ |
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@cf-bottom jenkins please |
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Sure, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14148/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14148/ |
- Remove unnecessary NULL guards before free() in DeleteMountInfo(). free(NULL) is a C-standard no-op; bare calls match the surrounding convention (FreeOptionsList, VerifyMount, etc.). - Add assert(a != NULL) to LiveMountConverged, ReconcileMountOptions, FileSystemMountedCorrectly, and VerifyMountPromise to resolve the 15 null-dereference warnings. This follows the existing convention in VerifyInFstab, VerifyMount, and VerifyUnmount which already had these asserts.
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@cf-bottom jenkins please |
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Alright, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14151/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14151/ |
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Sure, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14155/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14155/ |
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@cf-bottom jenkins please |
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Alright, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14170/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14170/ |
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@cf-bottom jenkins please. |
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Sure, I triggered a build: Jenkins: https://ci.cfengine.com/job/pr-pipeline/14254/ Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-14254/ |
| * option and its bare form (e.g. noexec/exec). */ | ||
| { | ||
| /* A "no"-prefixed option vs its bare form, in either direction. */ | ||
| if ((strncmp(a, "no", 2) == 0) && (strcmp(a + 2, b) == 0)) |
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Use StringEqual()/StringNEqual()
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Done in ab145c1: switched to StringEqual/StringEqualN here (and the other new comparisons in this file).
| /* Parse comma-separated options string into an array of individual option strings. | ||
| * Returns a newly allocated array of char* pointers, terminated by NULL. | ||
| * Caller must free the array itself (not the individual strings). */ | ||
| static char **ParseOptionsList(const char *opts) |
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See if you can use
Seq *SeqStringFromString(const char *str, char delimiter);or
char **String2StringArray(const char *str, char separator);
void FreeStringArray(char **strs);instead.
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Done in ab145c1: replaced the hand-rolled ParseOptionsList/FreeOptionsList with SeqStringFromString.
| free(arr); | ||
| } | ||
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| static bool InverseOptions(const char *a, const char *b) |
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Maybe ConflictingOptions would be a better name for this function?
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Done: renamed to ConflictingOptions in ab145c1.
| for (int i = 0; arr[i] != NULL; i++) | ||
| { | ||
| const char *tok = (strcmp(arr[i], "defaults") == 0) | ||
| ? "rw,suid,dev,exec,async" : arr[i]; | ||
| int w = snprintf(buf + n, sizeof(buf) - n, "%s%s", (i > 0) ? "," : "", tok); | ||
| if ((w < 0) || ((size_t) w >= sizeof(buf) - n)) | ||
| { | ||
| break; /* option list longer than CF_BUFSIZE; stop appending */ | ||
| } | ||
| n += (size_t) w; | ||
| } |
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Consider using
char *StringJoin(const Seq *seq, const char *sep);instead.
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Done in ab145c1: builds a Seq and joins it with StringJoin instead of the manual snprintf append.
| static const char *const comps[] = { "rw", "suid", "dev", "exec", "async" }; | ||
| for (size_t c = 0; c < sizeof(comps) / sizeof(comps[0]); c++) | ||
| { | ||
| SeqAppend(eff, xstrdup(comps[c])); | ||
| } |
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This you could one line with something like
Seq *eff = SeqStringFromString("rw,suid,dev,exec,async", ",");There was a problem hiding this comment.
Done in ab145c1: SeqStringFromString("rw,suid,dev,exec,async", ',') appended via SeqAppendSeq + SeqSoftDestroy.
| /* Last wins: skip this option if a later one overrides it (its inverse) | ||
| * or repeats it. */ | ||
| bool overridden = false; | ||
| for (size_t j = i + 1; j < SeqLength(eff); j++) |
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Not a big deal, but calling SeqLength() once before the loop is more efficient then every iteration of the loop.
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Done in ab145c1: SeqLength is taken once into a local before the loop (here and in the option-matching helper).
| } | ||
| if (StringEqual(a->mount.mount_type, "panfs")) | ||
| { | ||
| snprintf(comm, CF_BUFSIZE, "%s -t panfs -o %s %s%s %s", CommandArg0(VMOUNTCOMM[VSYSTEMHARDCLASS]), opts, host, rmountpt, mountpt); |
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It would be nice if you check the returned value of snprintf. Check that the buffer was not truncated. If truncation is impossible, then at least an assert would be nice to test that assumption in DEBUG builds.
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Done in ab145c1: the mount/unmount/remount command builds now use NDEBUG_UNUSED int ret = snprintf(...); assert(ret >= 0 && ret < CF_BUFSIZE);, matching the fstab builders in this file.
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| free(line); | ||
| } | ||
| else if ((strstr(line, "busy")) || (strstr(line, "Busy"))) |
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Please use explicit comparisons as described in CONTRIBUTING.md. E.g. strstr(line, "busy") != NULL
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Done in ab145c1: both busy checks now use strstr(line, "busy") != NULL.
| if (a->mount.editfstab) | ||
| /* CFE-90: distinguish "not mounted at all" from "mounted, but not as | ||
| * promised" (wrong source, or drifted options with remount enabled). */ | ||
| for (size_t i = 0; i < SeqLength(GetGlobalMountedFSList()); i++) |
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Consider calling GetGlobalMountedFSList only once. And consider moving SeqLength out of the loop condition to avoid it being called every iteration like mentioned before.
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Done — GetGlobalMountedFSList() is now called once into a local and SeqLength is hoisted out of the loop condition.
While here: this file uses raw strcmp throughout (no StringEqual anywhere). I switched the new strcmps to StringEqual in nfs.c per your other comment, but left verify_storage.c alone to match its own style. Convert them here too while I'm in this PR, or leave as-is?
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I don't see that this was fixed. Maybe it ended up in the wrong commit?
Addressed larsewi's review on PR cfengine#6222 (no behavior change; nfs_test still passes): - Replaced hand-rolled option parsing/joining with SeqStringFromString and StringJoin, and strcmp/strncmp with StringEqual/StringEqualN. - Renamed InverseOptions to ConflictingOptions. - Hoisted SeqLength and GetGlobalMountedFSList out of loops. - Checked snprintf for truncation and used explicit != NULL comparisons. Ticket: CFE-90 Changelog: None Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Thanks! Some minor nit picks. It would also be nice if you could amend the fixes from the last commit to the relevant commits that introduced them. It would make it easier for me to review this PR commit for commit. It's already very large / difficult to review / hard to keep all the context in my head.
| static bool ConflictingOptions(const char *a, const char *b) | ||
| /* True if 'a' and 'b' are mutually exclusive mount options that cannot both | ||
| * hold: ro/rw, hard/soft, sync/async, noatime/relatime, or a "no"-prefixed | ||
| * option and its bare form (e.g. noexec/exec). */ |
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Put docs above the function signature and use the doxygen (double star) syntax. This way editors will show this text when you hover over the symbol name.
| static bool ConflictingOptions(const char *a, const char *b) | |
| /* True if 'a' and 'b' are mutually exclusive mount options that cannot both | |
| * hold: ro/rw, hard/soft, sync/async, noatime/relatime, or a "no"-prefixed | |
| * option and its bare form (e.g. noexec/exec). */ | |
| /** | |
| * True if 'a' and 'b' are mutually exclusive mount options that cannot both | |
| * hold: ro/rw, hard/soft, sync/async, noatime/relatime, or a "no"-prefixed | |
| * option and its bare form (e.g. noexec/exec). | |
| */ | |
| static bool ConflictingOptions(const char *a, const char *b) |
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Done — moved the docs above the signature and switched to /**. Applied the same to the other new helpers in this file (OptionPresent, RemountOptionString, OptionsSubsetMatches, LiveMountConverged, ReconcileMountOptions) for consistency.
| return false; | ||
| } | ||
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| static bool InversePresent(const char *opt, const Seq *actual) |
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This should probably also be renamed, since the other one was?
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Done — renamed to ConflictingOptionPresent.
| NDEBUG_UNUSED int ret; | ||
| if (ropts != NULL) | ||
| { | ||
| ret = snprintf(comm, CF_BUFSIZE, "%s -o remount,%s %s", | ||
| CommandArg0(VMOUNTCOMM[VSYSTEMHARDCLASS]), ropts, name); | ||
| } | ||
| else | ||
| { | ||
| ret = snprintf(comm, CF_BUFSIZE, "%s -o remount %s", | ||
| CommandArg0(VMOUNTCOMM[VSYSTEMHARDCLASS]), name); | ||
| } | ||
| assert(ret >= 0 && ret < CF_BUFSIZE); |
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I would move the ret declaration and put the assert inside the if branches. This way the ret variable goes out of scope afterwards. Furthermore, you will see which branch triggered the assertion. And you don't save any lines of code by having it outside.
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Done — ret is now declared and asserted inside each branch.
| for (size_t i = 0; i < n_mounted; i++) | ||
| { | ||
| Mount *mp = SeqAt(mounted_fs, i); | ||
| if (mp != NULL && mp->mounton != NULL && strcmp(name, mp->mounton) == 0) |
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| if (mp != NULL && mp->mounton != NULL && strcmp(name, mp->mounton) == 0) | |
| if (mp != NULL && mp->mounton != NULL && StringEqual(name, mp->mounton)) |
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Done. Per my earlier question, I used StringEqual on the PR-touched lines here and left the other (untouched) strcmps in this file alone.
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Yepp, I would keep untouched code alone for the sake of the git history.
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Thanks! Nits addressed, and the trailing fixup commit is gone — its changes, the new nits, and the CodeQL NULL-guards are all folded into the commits that introduced the code, so the PR is now five clean commits that read commit-by-commit. Each commit builds and |
Previously mount_options only affected the initial fstab write and the
initial mount; a filesystem already mounted with the wrong options was
never corrected, because `mount -a` skips already-mounted filesystems.
This adds opt-in reconciliation of a live mount when its options drift
from the promise.
New mount body attributes:
- remount (default false): manage the options of an already-mounted
filesystem. When false a mounted filesystem with the correct source is
considered kept regardless of option drift (backwards compatible;
options still drive the initial mount and, with edit_fstab, the fstab
entry).
- remount_methods (default { remount }): ordered mechanisms tried in turn,
re-reading the live mount after each to verify it satisfies the promise.
Defaults to the non-disruptive in-place remount only; the disruptive
unmount_mount (which tears the filesystem down and back up, interrupting
anything using it) is opt-in and is required to change options a live
remount cannot, e.g. NFS-negotiated vers=/rsize= or the server. The
kernel returns success from a remount even when it silently ignores
NFS-negotiated options, so the resulting state is verified rather than
the command exit status trusted.
- remount_timeout: bounds the unmount/mount path against a hung or
unreachable server.
When reconciliation is enabled the live mount is corrected first; if
edit_fstab is set the fstab entry is then updated regardless of the live
outcome (recording intent moves the system closer to the desired state,
and the live result is reported as its own promise outcome).
The promise is matched against the live mount by first resolving it with
util-linux "last wins" semantics - exactly as `mount -o` applies a list, a
later option overrides an earlier conflicting one (so "defaults,ro" is a
read-only mount and "ro,rw" is rw) - and then checking each surviving option.
Only the options the promise names are enforced; any option it does not name
is left unpoliced, because its provenance is unknown (kernel-negotiated like
vers=/rsize=, or added by a prior manual mount, indistinguishable). An option
the promise does specify - including a negotiated one such as rsize=8192 -
must be present in the live mount, with its inverse absent. Inverse pairs
(noatime/relatime, hard/soft, ro/rw, sync/async, generic no<opt>/<opt>) and
tcp/udp<->proto= aliases are recognized. The "defaults" pseudo-option (never
echoed by the kernel) expands to its checkable components rw,suid,dev,exec,
async (mount(8): defaults = rw,suid,dev,exec,auto,nouser,async; auto/nouser
are fstab/permission concepts, not runtime state, so they are not enforced) -
so "defaults" holds unless ro/nosuid/nodev/noexec/sync is present, and a later
explicit option can override any of those components. A correctly-mounted
filesystem thus converges instead of being reported changed every run. When a
later option overrides an earlier conflicting one, that is logged at verbose.
When reconciling via an in-place remount, "defaults" is likewise expanded to
"rw,suid,dev,exec,async" in the mount command (util-linux does not apply the
options implied by a bare "defaults" on a remount), so a filesystem that has
drifted to read-only (or nosuid, etc.) is restored in place rather than only
via the disruptive unmount_mount; mount's own last-wins then applies any
trailing override (e.g. "defaults,ro" remounts as ...,ro).
Mount and unmount side effects are gated on the promise action
(MakingInternalChanges), not a bare !DONTDO: a dry-run (-n) or
action_policy => "warn" promise now reports WARN without defining the
classes body's promise_repaired set, so a dependent promise keyed on
those classes no longer fires on a no-op run (CFE-3366). A live remount
is a real side effect outside the simulate sandbox, so the normal-mode
gate is used.
Also corrects the mount-info handling this relies on:
- GetFstabEntryOptions returned the fstab type field instead of the
options field, causing a spurious fstab rewrite and reported change
every run.
- ReplaceFstabEntry leaked the previous entry string.
- The mounted-FS scan no longer dropped the fstype used by
IsForeignFileSystem; fstype and kernel-resolved options are now stored
separately (options vs raw_opts).
- Restored unconditional creation of the mount point directory before
mounting, and stopped arming `mount -a` for an already-mounted
filesystem.
- "device busy" interruptions are logged at LOG_LEVEL_ERR (the outcome is
INTERRUPTED, cf. RecordInterruption), and the leaked options strings on
the error paths are freed.
- VerifyUnmount consulted feof() after cf_pclose() had already closed the
stream (a use-after-close): a silent, successful unmount then logged a
bogus "Unable to read output of unmount command" and returned before the
success cfPS(), reporting NOOP with no promise_repaired class instead of a
change. feof() is now captured before cf_pclose() invalidates the stream.
The unmount_mount remount method depends on this outcome being correct.
References for the kernel/OS behavior asserted in the option-matching and
convergence code: mount(8) (`mount -a` skips already-mounted filesystems;
`defaults` = rw,suid,dev,exec,auto,nouser,async) and nfs(5) (options
negotiated by client and server are reported in /proc/mounts; NFS-specific
options cannot be changed by a remount).
Ticket: CFE-90
Ticket: CFE-1864
Ticket: CFE-3366
Changelog: Title
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Covers OptionsSubsetMatches: named-option-only enforcement (kernel-added options ignored), order independence for non-conflicting options, inverse pairs (noatime/relatime, ro/rw, hard/soft, sync/async, generic no<opt>/<opt>), tcp/udp<->proto= aliases, the "defaults" expansion (held unless ro/nosuid/nodev/noexec/sync is present), and the "last wins" resolution of conflicting options (defaults,ro -> read-only; ro,rw -> rw; a later explicit option overrides a "defaults" component). Also covers RemountOptionString (expanding "defaults" to rw,suid,dev,exec,async for the remount command). Runs unprivileged in CI via "make -C tests/unit check"; the behavioral mount/remount test belongs in the system-testing repo (needs root + a real NFS server). Ticket: CFE-90 Changelog: None Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A storage promise whose filesystem was already mounted with the correct source reported "mounted as promised" and never touched fstab, so a missing fstab entry was not restored and an options change was not written to fstab (CFE-1539). VerifyInFstab now also runs on the mounted-correctly path (when edit_fstab is set), independent of the opt-in live 'remount': keeping fstab correct is the documented behavior of mount_options, while remounting a live filesystem stays the disruptive, opt-in part gated by 'remount'. The fstab options comparison is left exact (order-sensitive): fstab option order is significant for duplicated/conflicting options, and the earlier GetFstabEntryOptions fix already stops the every-run rewrites. Ticket: CFE-1539 Changelog: Title
A storage promise for a not-yet-mounted filesystem armed CF_MOUNTALL, so CFEngine ran 'mount -a'/'mount -va' at the end of the pass. That mounts every unmounted entry in fstab - unrelated devices and foreign filesystem types included - as a side effect of a single promise (CFE-1863). The not-mounted path now mounts just the promised filesystem with VerifyMount (the existing surgical primitive), then persists it to fstab when edit_fstab is set. CF_MOUNTALL / MountAll are kept for the explicit 'mountfilesystems' agent control, which still means "mount everything in fstab". Ticket: CFE-1863 Changelog: Title
An unmount promise that named mount_source/mount_server was warned about as "probably an error", and the server was never used to select which mount to act on - so a policy could not unmount one specific mount (e.g. from a server being migrated away) without affecting others (CFE-2350). The bogus warning is removed, and the server (host) is now part of the "mounted correctly" identity check, gated on remount or unmount so it only engages when the promise opts into disruptive mount management. An unmount promise that finds a *different* filesystem at the mount point now leaves it - and its fstab entry - untouched. LiveMountConverged likewise treats the server as part of identity, so a remount-in-place that cannot change the server escalates to unmount_mount. Ticket: CFE-2350 Changelog: Title
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| static bool OptionPresent(const char *opt, const Seq *actual) | ||
| { | ||
| const size_t len = SeqLength(actual); | ||
| for (size_t a = 0; a < len; a++) |
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The convention is to use i for the index variable, then j, k, etc. for nested loops.
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| Seq *in = SeqStringFromString(opts, ','); | ||
| const size_t len = SeqLength(in); | ||
| Seq *out = SeqNew(len + 4, free); |
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Adding four to the initial capacity does not help. I guess the thought was that you expect at most one occurrences of defaults. We add five options below (rw,suid,dev,exec,async) while removing one (defaults). Hence, we need four more slots. However, the five options below replaces the defaults option as a single element in the sequence. Thus, the final capacity is the exact length of the original sequence.
Furthermore, instead of creating two sequences, you should use
void SeqSet(Seq *set, size_t index, void *item);on the original one to mutate it in place.
| /* Expand "defaults" in place, preserving order for the last-wins pass. */ | ||
| Seq *eff = SeqNew(16, free); | ||
| const size_t n_promised = SeqLength(promised); | ||
| for (size_t p = 0; p < n_promised; p++) | ||
| { | ||
| const char *opt = SeqAt(promised, p); | ||
| if (StringEqual(opt, "defaults")) | ||
| { | ||
| Seq *comps = SeqStringFromString("rw,suid,dev,exec,async", ','); | ||
| SeqAppendSeq(eff, comps); | ||
| SeqSoftDestroy(comps); /* eff now owns the expanded components */ | ||
| } | ||
| else | ||
| { | ||
| SeqAppend(eff, xstrdup(opt)); | ||
| } | ||
| } |
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Can't you use the
static char *RemountOptionString(const char *opts);function above? It appears to be doing the exact same thing.
It should probably be renamed to OptionStringExpandDefaults() if you decide re-use it.
| { | ||
| /* CFE-90: Entry exists - check if options differ and update if needed */ | ||
| char *existing_opts = GetFstabEntryOptions(mountpt); | ||
| if (existing_opts != NULL && strcmp(existing_opts, opts) != 0) |
| cfPS(ctx, LOG_LEVEL_INFO, PROMISE_RESULT_INTERRUPTED, pp, a, "The device under '%s' cannot be removed from '%s'", | ||
| cfPS(ctx, LOG_LEVEL_ERR, PROMISE_RESULT_INTERRUPTED, pp, a, "The device under '%s' cannot be removed from '%s'", |
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This seems like it belongs in a separate commit?
| for (size_t i = 0; i < SeqLength(GetGlobalMountedFSList()); i++) | ||
| { | ||
| Mount *mp = SeqAt(GetGlobalMountedFSList(), i); | ||
| if (mp != NULL && mp->mounton != NULL && strcmp(name, mp->mounton) == 0) |
| if (a->mount.editfstab) | ||
| /* CFE-90: distinguish "not mounted at all" from "mounted, but not as | ||
| * promised" (wrong source, or drifted options with remount enabled). */ | ||
| for (size_t i = 0; i < SeqLength(GetGlobalMountedFSList()); i++) |
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I don't see that this was fixed. Maybe it ended up in the wrong commit?
| s = RemountOptionString("defaults,noatime"); | ||
| assert_true(strcmp(s, "rw,suid,dev,exec,async,noatime") == 0); free(s); | ||
| /* Everything else is passed through unchanged and order-preserved. */ | ||
| s = RemountOptionString("rw,noatime"); assert_true(strcmp(s, "rw,noatime") == 0); free(s); |
| /* "defaults" expands to its checkable positives so an in-place remount | ||
| * restores a mount that drifted to ro/nosuid/etc (util-linux does not honor | ||
| * the options implied by "defaults" on a remount). */ | ||
| s = RemountOptionString("defaults"); |
| * promise opts in via remount or unmount. */ | ||
| if ((a->mount.remount || a->mount.unmount) | ||
| && (a->mount.mount_server != NULL) | ||
| && ((mp->host == NULL) || (strcmp(mp->host, a->mount.mount_server) != 0))) |
5 participants
Storage/mount promises only applied
mount_optionsto the initial mount and (ifedit_fstabis enabled) the fstab entry. A filesystem already mounted with different options was never corrected, becausemount -askips already-mounted filesystems. This PR adds opt-in reconciliation of a live mount when its options drift from the promise, and along the way fixes several long-standing storage-promise bugs (CFE-1539, CFE-1863, CFE-2350, CFE-3366).Opt-in live remount reconciliation (CFE-90, CFE-1864)
New
mountbody attributes:remount(defaultfalse) — reconcile a live mount's options when they differ. When false, a mounted filesystem with the correct source is kept regardless of option drift (backwards compatible; options still drive the initial mount and, withedit_fstab, the fstab entry).remount_methods(default{ remount }) — mechanisms tried in order, re-reading the live mount after each (the kernel returns success from a remount even when it silently ignores NFS-negotiated options). Defaults to the non-disruptive in-placeremountonly; the disruptiveunmount_mount(which tears the filesystem down and back up) is opt-in, and is required to change options a live remount cannot — e.g. NFS-negotiatedvers=/rsize=, or the server.remount_timeout— protect against a hung or unreachable server.Option comparison (live mount). Only the options the promise names are enforced; any option it does not name is left unpoliced — its provenance is unknown (kernel-negotiated like
vers=/rsize=/proto=/sec=, or added by a prior manualmount -o, indistinguishable). The promise is first resolved with util-linux "last wins" semantics — exactly asmount -oapplies a list, a later option overrides an earlier conflicting one, sodefaults,rois a read-only mount andro,rwisrw. Each surviving option must then hold on the live mount: its inverse absent, and it either present or a default-on flag. Inverse pairs (noatime/relatime,hard/soft,ro/rw,sync/async, genericno<opt>/<opt>) andtcp/udp↔proto=aliases are recognized; an option the promise specifies (including a negotiated one such asrsize=8192) must be present. A correctly-mounted filesystem converges instead of being reported changed every run, and an override (roshadowing an earlierrw) is logged at verbose.The
defaultspseudo-option.defaults(=rw,suid,dev,exec,auto,nouser,async, per mount(8)) is never echoed by the kernel, so it's expanded to its checkable componentsrw,suid,dev,exec,asyncand subjected to the same last-wins resolution. It holds unless one of the violating negatives is present —ro(vsrw),nosuid/nodev/noexec(vssuid/dev/exec), orsync(vsasync) — and a later explicit option overrides the matching component (sodefaults,rorequires read-only,defaults,nosuidallowsnosuid).auto/nouserare fstab / mount-permission concepts, not runtime state, so they aren't enforced. When reconciling a drifteddefaultsmount in place, the remount command likewise usesrw,suid,dev,exec,async(util-linux doesn't apply the options implied by a baredefaultson a remount), and mount's own last-wins applies any trailing override — so a mount that drifted toro/nosuid/etc. is restored non-disruptively rather than only viaunmount_mount.fstab maintenance for already-mounted filesystems (CFE-1539)
Previously a filesystem already mounted with the correct source was reported "mounted as promised" and fstab was never consulted, so a missing fstab entry was not restored and an options change was not written until the mount happened to be redone.
VerifyInFstabnow runs on the mounted-correctly path too (whenedit_fstab => "true"), deliberately independent of the opt-in liveremount: keeping fstab correct is the documented behavior ofmount_options. fstab option comparison usesstrcmpbecause option order matters.Surgical single-filesystem mount, not
mount -a(CFE-1863)A storage promise for a not-yet-mounted filesystem used to arm
mount -a(mount -vaon Linux), which mounts every unmounted fstab entry — unrelated devices and foreign filesystem types included — as a side effect of a single promise. The not-mounted path now mounts just the promised filesystem surgically (VerifyMount), then persists it to fstab. Themount -amechanism (MountAll) is retained only for the explicitmountfilesystemsagent-control attribute, which still means "mount everything in fstab".Target a specific mount on unmount (CFE-2350)
An unmount promise that named
mount_source/mount_serverwas logged as "probably an error", and the server was never used to pick which mount to act on — so you couldn't unmount one specific mount (e.g. from a server being migrated away) without affecting others. The bogus warning is removed, and the server (host) is now part of the "mounted correctly" identity check, gated onremountorunmountso it only engages when the promise opts into disruptive mount management. An unmount promise that finds a different filesystem at the mount point leaves it — and its fstab entry — untouched, andLiveMountConvergedtreats the server as identity so a remount-in-place that can't change it escalates tounmount_mount.Correct dry-run / warn reporting (CFE-3366)
The mount, unmount and remount outcomes are based on the promise action (
MakingInternalChanges) rather than a bare!DONTDO. A dry-run (-n) orwarnpromise now reportsWARNwithout definingpromise_repaired, so dependent promises no longer fire on a no-op run.Supporting mount-info fixes
GetFstabEntryOptionsreturned the fstab type field instead of the options field (spurious rewrite every run).ReplaceFstabEntryleaked the previous entry string.optionsvsraw_opts).LOG_LEVEL_ERR(the outcome isINTERRUPTED), and leaked options strings on the error paths are freed.Testing
Unit coverage in
tests/unit/nfs_test.c(option subset matching, inverse/alias pairs, thedefaultsnegative-violation check, contradiction detection, and thedefaults→rw,suid,dev,exec,asyncremount expansion), runnable unprivileged viamake -C tests/unit check. The behavioral NFS reconcile/escalation, fstab maintenance, and surgical single-filesystem mount — which need root and a real NFS server — are covered by the system-testing PR and were exercised against a loopback NFS export during development.Commits
References
mount -askipping already-mounted filesystems, anddefaults=rw,suid,dev,exec,auto,nouser,async— mount(8)/proc/mounts) and NFS-specific options not modifiable on remount — nfs(5)Resolves CFE-90 (and its duplicate CFE-1864), CFE-1539 (fstab maintenance), CFE-1863 (
mount -ascope), CFE-2350 (target a specific mount on unmount), and CFE-3366 (dry-run/warn definingpromise_repaired) for storage mount promises.Ticket: https://northerntech.atlassian.net/browse/CFE-90
Together with: https://github.com/cfengine/system-testing/pull/693