| Summary: | 'tail -f' waits forever for inotify | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Eduardo Habkost <ehabkost> | ||||||||
| Component: | kernel | Assignee: | Eric Paris <eparis> | ||||||||
| Status: | CLOSED ERRATA | QA Contact: | Red Hat Kernel QE team <kernel-qe> | ||||||||
| Severity: | unspecified | Docs Contact: | |||||||||
| Priority: | unspecified | ||||||||||
| Version: | 6.1 | CC: | arozansk, eparis, tburke | ||||||||
| Target Milestone: | rc | ||||||||||
| Target Release: | --- | ||||||||||
| Hardware: | Unspecified | ||||||||||
| OS: | Unspecified | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | 675299 | Doc Type: | Bug Fix | ||||||||
| Doc Text: | Story Points: | --- | |||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2011-05-19 12:43:11 UTC | Type: | --- | ||||||||
| Regression: | --- | Mount Type: | --- | ||||||||
| Documentation: | --- | CRM: | |||||||||
| Verified Versions: | Category: | --- | |||||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||||
| Bug Depends On: | |||||||||||
| Bug Blocks: | 676037 | ||||||||||
| Attachments: |
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oops, my sample script is wrong (it was supposed to use ">""). I'll send a better one in a few moments. Created attachment 477106 [details]
strace of script under 2.6.32-112.el6.x86_64
Updated script:
------------------
#!/bin/bash
f=/tmp/tail-test
echo file: $f
echo ok > "$f"
sleep 1
tail -f "$f" &
sleep 1
echo ok2 >> "$f"
wait
----------------
Updated strace output attached.
Created attachment 477108 [details]
strace of script under 2.6.32-108.el6.x86_64 (working)
2.6.32-108.el6.x86_64 seems to be working. strace attached.
Created attachment 477113 [details]
strace of script under 2.6.32-109.el6.x86_64 (broken)
Reproduced under 2.6.32-109.el6.x86_64.
This kernel bug breaks kvm autotest which is our main QA tool. It's a blocker from our POV. This was caused by my broken fix for BZ 582109. I have requested that the patch applied be reverted. I'm going to put this bug into the 'POST' state as a request to fix has been posted to the internal list. This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release. reproduced on -115, confirmed it's fixed on -117. An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0542.html |
Description of problem: when running 'tail -f' on some scenarios, it is failing to show new contents on files. Version-Release number of selected component (if applicable): 2.6.32-112.el6.x86_64 How reproducible: Always. Steps to Reproduce: Run the following script: ---------------- #!/bin/bash f=/tmp/tail-test echo file: $f echo ok > "$f" sleep 1 tail -f "$f" & sleep 1 echo ok2 > "$f" wait ------------------ Actual results: tail shows "ok" Expected results: tail shows "ok" and "ok2" lines. Additional info: strace output: [pid 30838] inotify_init() = 4 [pid 30838] inotify_add_watch(4, "/tmp/tail-test", IN_MODIFY|IN_ATTRIB|IN_DELETE_SELF|IN_MOVE_SELF) = 1 [pid 30838] fstat(3, {st_mode=S_IFREG|0644, st_size=3, ...}) = 0 [pid 30838] read(4, <unfinished ...> [pid 30839] <... nanosleep resumed> NULL) = 0 [pid 30839] close(1) = 0 [pid 30839] close(2) = 0 [pid 30839] exit_group(0) = ? Process 30835 resumed Process 30839 detached [pid 30835] <... wait4 resumed> [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 30839 [pid 30835] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 [pid 30835] --- SIGCHLD (Child exited) @ 0 (0) --- [pid 30835] wait4(-1, 0x7fff9ffbc25c, WNOHANG, NULL) = 0 [pid 30835] rt_sigreturn(0xffffffffffffffff) = 0 [pid 30835] rt_sigaction(SIGINT, {SIG_DFL, [], SA_RESTORER, 0x3bb2e32a20}, {0x43d220, [], SA_RESTORER, 0x3bb2e32a20}, 8) = 0 [pid 30835] rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0 [pid 30835] read(255, "echo ok2 > \"$f\"\nwait\n", 110) = 21 [pid 30835] write(2, "+ echo ok2\n", 11+ echo ok2 ) = 11 [pid 30835] open("/tmp/tail-test", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 [pid 30835] fcntl(1, F_GETFD) = 0 [pid 30835] fcntl(1, F_DUPFD, 10) = 10 [pid 30835] fcntl(1, F_GETFD) = 0 [pid 30835] fcntl(10, F_SETFD, FD_CLOEXEC) = 0 [pid 30835] dup2(3, 1) = 1 [pid 30835] close(3) = 0 [pid 30835] write(1, "ok2\n", 4) = 4 [pid 30835] dup2(10, 1) = 1 [pid 30835] fcntl(10, F_GETFD) = 0x1 (flags FD_CLOEXEC) [pid 30835] close(10) = 0 [pid 30835] rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0 [pid 30835] write(2, "+ wait\n", 7+ wait