diff options
| -rw-r--r-- | net/sunrpc/cache.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 8a7e1c774f9c..26582e27be6a 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -1450,8 +1450,8 @@ static ssize_t write_flush(struct file *file, const char __user *buf, struct cache_detail *cd) { char tbuf[20]; - char *bp, *ep; - time_t then, now; + char *ep; + time_t now; if (*ppos || count > sizeof(tbuf)-1) return -EINVAL; @@ -1461,24 +1461,24 @@ static ssize_t write_flush(struct file *file, const char __user *buf, simple_strtoul(tbuf, &ep, 0); if (*ep && *ep != '\n') return -EINVAL; + /* Note that while we check that 'buf' holds a valid number, + * we always ignore the value and just flush everything. + * Making use of the number leads to races. + */ - bp = tbuf; - then = get_expiry(&bp); now = seconds_since_boot(); - cd->nextcheck = now; - /* Can only set flush_time to 1 second beyond "now", or - * possibly 1 second beyond flushtime. This is because - * flush_time never goes backwards so it mustn't get too far - * ahead of time. + /* Always flush everything, so behave like cache_purge() + * Do this by advancing flush_time to the current time, + * or by one second if it has already reached the current time. + * Newly added cache entries will always have ->last_refresh greater + * that ->flush_time, so they don't get flushed prematurely. */ - if (then >= now) { - /* Want to flush everything, so behave like cache_purge() */ - if (cd->flush_time >= now) - now = cd->flush_time + 1; - then = now; - } - cd->flush_time = then; + if (cd->flush_time >= now) + now = cd->flush_time + 1; + + cd->flush_time = now; + cd->nextcheck = now; cache_flush(); *ppos += count; |