fs: stop recursive mkdir from retrying ENOENT forever - #66340
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| try { | ||
| fs.mkdirSync(dir); | ||
| } catch (err) { | ||
| if (err.code !== 'ENOENT') common.skip(`mkdir under /proc fails with ${err.code}`); |
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Because the bug is triggerd when `mklkdir() returns ENOENT.
But you are right, is a useless guard here, removed
When mkdir() fails with ENOENT, the recursive algorithm assumes the
parent is missing, creates it and retries. On procfs mkdir() keeps
returning ENOENT although the parent exists, and under a concurrent
rmdir() the parent can disappear again, so the retry loop never
terminates: `fs.mkdirSync('/proc/x', { recursive: true })` spins at
100% CPU.
Retry a path that failed with ENOENT only once and report ENOENT the
second time, like the non-recursive call does.
Fixes: nodejs#66268
Signed-off-by: marcopiraccini <marco.piraccini@gmail.com>
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #66340 +/- ##
==========================================
- Coverage 90.38% 90.36% -0.02%
==========================================
Files 790 792 +2
Lines 274497 275400 +903
Branches 52557 52781 +224
==========================================
+ Hits 248100 248875 +775
- Misses 16879 16951 +72
- Partials 9518 9574 +56
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Signed-off-by: marcopiraccini <marco.piraccini@gmail.com>
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| fs.mkdir(dir, { recursive: true }, common.mustCall((err) => { | ||
| assert.strictEqual(err.code, expected.code); | ||
| assert.strictEqual(err.syscall, expected.syscall); | ||
| })); |
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I think this could be simplified to
Suggested change
| fs.mkdir(dir, { recursive: true }, common.mustCall((err) => { | |
| assert.strictEqual(err.code, expected.code); | |
| assert.strictEqual(err.syscall, expected.syscall); | |
| })); | |
| fs.mkdir(dir, { recursive: true }, common.expectsError(expected)); |
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When
mkdir()returnsENOENT, recursive mkdir assumes that the parent directory is missing, creates it, and retries the original path.This can loop indefinitely when the parent exists but
mkdir()continues to returnENOENT, as it does under/proc. The same loop can occur if another process removes a parent directory during the operation.Track paths that have already returned
ENOENT. Retry each path once after handling its parent, then returnENOENTif the retry also fails.Fixes: #66268