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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2017-05-31 09:17:39 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-06-01 08:44:51 +1000 |
| commit | 33f16ba0f7e3879861c4d166d08aff9cca57bfac (patch) | |
| tree | 32ae733d9ea362d7c4ec4e9790353ad50fee6563 /Documentation | |
| parent | 63243c1e81be299a9387d5651a9c57d18a639d86 (diff) | |
fault-inject: make fail-nth read/write interface symmetric
The read interface for fail-nth looks a bit odd. Read from this file
returns "NYYYY..." or "YYYYY..." (this makes me surprise when cat this
file). Because there is no EOF condition. The first character indicates
current->fail_nth is zero or not, and then current->fail_nth is reset to
zero.
Just returning task->fail_nth value is more natural to understand.
Link: http://lkml.kernel.org/r/1491490561-10485-4-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/fault-injection/fault-injection.txt | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt index a32190508751..370ddcbc2b44 100644 --- a/Documentation/fault-injection/fault-injection.txt +++ b/Documentation/fault-injection/fault-injection.txt @@ -139,9 +139,9 @@ o proc entries - /proc/self/task/<current-tid>/fail-nth: Write to this file of integer N makes N-th call in the task fail. - Read from this file returns a single char 'Y' or 'N' - that says if the fault setup with a previous write to this file was - injected or not, and disables the fault if it wasn't yet injected. + Read from this file returns a integer value. A value of '0' indicates + that the fault setup with a previous write to this file was injected. + A positive integer N indicates that the fault wasn't yet injected. Note that this file enables all types of faults (slab, futex, etc). This setting takes precedence over all other generic debugfs settings like probability, interval, times, etc. But per-capability settings @@ -325,13 +325,14 @@ int main() write(fail_nth, buf, strlen(buf)); res = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds); err = errno; - read(fail_nth, buf, 1); + pread(fail_nth, buf, sizeof(buf), 0); if (res == 0) { close(fds[0]); close(fds[1]); } - printf("%d-th fault %c: res=%d/%d\n", i, buf[0], res, err); - if (buf[0] != 'Y') + printf("%d-th fault %c: res=%d/%d\n", i, atoi(buf) ? 'N' : 'Y', + res, err); + if (atoi(buf)) break; } return 0; |