diff options
Diffstat (limited to 'fs/eventpoll.c')
| -rw-r--r-- | fs/eventpoll.c | 58 |
1 files changed, 33 insertions, 25 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 3817149919cb..cc8a9b7d6064 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -77,9 +77,6 @@ /* Maximum number of nesting allowed inside epoll sets */ #define EP_MAX_NESTS 4 -/* Maximum msec timeout value storeable in a long int */ -#define EP_MAX_MSTIMEO min(1000ULL * MAX_SCHEDULE_TIMEOUT / HZ, (LONG_MAX - 999ULL) / HZ) - #define EP_MAX_EVENTS (INT_MAX / sizeof(struct epoll_event)) #define EP_UNACTIVE_PTR ((void *) -1L) @@ -220,7 +217,7 @@ struct ep_send_events_data { * Configuration options available inside /proc/sys/fs/epoll/ */ /* Maximum number of epoll watched descriptors, per user */ -static int max_user_watches __read_mostly; +static long max_user_watches __read_mostly; /* * This mutex is used to serialize ep_free() and eventpoll_release_file(). @@ -243,16 +240,18 @@ static struct kmem_cache *pwq_cache __read_mostly; #include <linux/sysctl.h> -static int zero; +static long zero; +static long long_max = LONG_MAX; ctl_table epoll_table[] = { { .procname = "max_user_watches", .data = &max_user_watches, - .maxlen = sizeof(int), + .maxlen = sizeof(max_user_watches), .mode = 0644, - .proc_handler = proc_dointvec_minmax, + .proc_handler = proc_doulongvec_minmax, .extra1 = &zero, + .extra2 = &long_max, }, { } }; @@ -564,7 +563,7 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi) /* At this point it is safe to free the eventpoll item */ kmem_cache_free(epi_cache, epi); - atomic_dec(&ep->user->epoll_watches); + atomic_long_dec(&ep->user->epoll_watches); return 0; } @@ -674,7 +673,8 @@ static unsigned int ep_eventpoll_poll(struct file *file, poll_table *wait) /* File callbacks that implement the eventpoll file behaviour */ static const struct file_operations eventpoll_fops = { .release = ep_eventpoll_release, - .poll = ep_eventpoll_poll + .poll = ep_eventpoll_poll, + .llseek = noop_llseek, }; /* Fast test to see if the file is an evenpoll file */ @@ -900,11 +900,12 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, { int error, revents, pwake = 0; unsigned long flags; + long user_watches; struct epitem *epi; struct ep_pqueue epq; - if (unlikely(atomic_read(&ep->user->epoll_watches) >= - max_user_watches)) + user_watches = atomic_long_read(&ep->user->epoll_watches); + if (unlikely(user_watches >= max_user_watches)) return -ENOSPC; if (!(epi = kmem_cache_alloc(epi_cache, GFP_KERNEL))) return -ENOMEM; @@ -968,7 +969,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, spin_unlock_irqrestore(&ep->lock, flags); - atomic_inc(&ep->user->epoll_watches); + atomic_long_inc(&ep->user->epoll_watches); /* We have to call this outside the lock */ if (pwake) @@ -1116,18 +1117,22 @@ static int ep_send_events(struct eventpoll *ep, static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events, int maxevents, long timeout) { - int res, eavail; + int res, eavail, timed_out = 0; unsigned long flags; - long jtimeout; + long slack; wait_queue_t wait; - - /* - * Calculate the timeout by checking for the "infinite" value (-1) - * and the overflow condition. The passed timeout is in milliseconds, - * that why (t * HZ) / 1000. - */ - jtimeout = (timeout < 0 || timeout >= EP_MAX_MSTIMEO) ? - MAX_SCHEDULE_TIMEOUT : (timeout * HZ + 999) / 1000; + struct timespec end_time; + ktime_t expires, *to = NULL; + + if (timeout > 0) { + ktime_get_ts(&end_time); + timespec_add_ns(&end_time, (u64)timeout * NSEC_PER_MSEC); + slack = select_estimate_accuracy(&end_time); + to = &expires; + *to = timespec_to_ktime(end_time); + } else if (timeout == 0) { + timed_out = 1; + } retry: spin_lock_irqsave(&ep->lock, flags); @@ -1149,7 +1154,7 @@ retry: * to TASK_INTERRUPTIBLE before doing the checks. */ set_current_state(TASK_INTERRUPTIBLE); - if (!list_empty(&ep->rdllist) || !jtimeout) + if (!list_empty(&ep->rdllist) || timed_out) break; if (signal_pending(current)) { res = -EINTR; @@ -1157,7 +1162,9 @@ retry: } spin_unlock_irqrestore(&ep->lock, flags); - jtimeout = schedule_timeout(jtimeout); + if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS)) + timed_out = 1; + spin_lock_irqsave(&ep->lock, flags); } __remove_wait_queue(&ep->wq, &wait); @@ -1175,7 +1182,7 @@ retry: * more luck. */ if (!res && eavail && - !(res = ep_send_events(ep, events, maxevents)) && jtimeout) + !(res = ep_send_events(ep, events, maxevents)) && !timed_out) goto retry; return res; @@ -1422,6 +1429,7 @@ static int __init eventpoll_init(void) */ max_user_watches = (((si.totalram - si.totalhigh) / 25) << PAGE_SHIFT) / EP_ITEM_COST; + BUG_ON(max_user_watches < 0); /* Initialize the structure used to perform safe poll wait head wake ups */ ep_nested_calls_init(&poll_safewake_ncalls); |