diff options
author | Arnd Bergmann <arnd@arndb.de> | 2017-10-20 16:34:42 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2019-12-18 18:07:32 +0100 |
commit | f559935e7ce4e5d448bb6588f7fa82b0cc2cc2c0 (patch) | |
tree | 7f5b52dee60425b1be9bda95980f4f1675491387 /net/sunrpc/cache.c | |
parent | 294ec5b87a8aaef664efb00ba62e4ef6ca05707c (diff) | |
download | linux-f559935e7ce4e5d448bb6588f7fa82b0cc2cc2c0.tar.bz2 |
nfs: use time64_t internally
The timestamps for the cache are all in boottime seconds, so they
don't overflow 32-bit values, but the use of time_t is deprecated
because it generally does overflow when used with wall-clock time.
There are multiple possible ways of avoiding it:
- leave time_t, which is safe here, but forces others to
look into this code to determine that it is over and over.
- use a more generic type, like 'int' or 'long', which is known
to be sufficient here but loses the documentation of referring
to timestamps
- use ktime_t everywhere, and convert into seconds in the few
places where we want realtime-seconds. The conversion is
sometimes expensive, but not more so than the conversion we
do today.
- use time64_t to clarify that this code is safe. Nothing would
change for 64-bit architectures, but it is slightly less
efficient on 32-bit architectures.
Without a clear winner of the three approaches above, this picks
the last one, favouring readability over a small performance
loss on 32-bit architectures.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'net/sunrpc/cache.c')
-rw-r--r-- | net/sunrpc/cache.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index f740cb51802a..d996bf872a7c 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -42,7 +42,7 @@ static bool cache_listeners_exist(struct cache_detail *detail); static void cache_init(struct cache_head *h, struct cache_detail *detail) { - time_t now = seconds_since_boot(); + time64_t now = seconds_since_boot(); INIT_HLIST_NODE(&h->cache_list); h->flags = 0; kref_init(&h->ref); @@ -139,10 +139,10 @@ EXPORT_SYMBOL_GPL(sunrpc_cache_lookup_rcu); static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); -static void cache_fresh_locked(struct cache_head *head, time_t expiry, +static void cache_fresh_locked(struct cache_head *head, time64_t expiry, struct cache_detail *detail) { - time_t now = seconds_since_boot(); + time64_t now = seconds_since_boot(); if (now <= detail->flush_time) /* ensure it isn't immediately treated as expired */ now = detail->flush_time + 1; @@ -274,7 +274,7 @@ int cache_check(struct cache_detail *detail, struct cache_head *h, struct cache_req *rqstp) { int rv; - long refresh_age, age; + time64_t refresh_age, age; /* First decide return status as best we can */ rv = cache_is_valid(h); @@ -288,7 +288,7 @@ int cache_check(struct cache_detail *detail, rv = -ENOENT; } else if (rv == -EAGAIN || (h->expiry_time != 0 && age > refresh_age/2)) { - dprintk("RPC: Want update, refage=%ld, age=%ld\n", + dprintk("RPC: Want update, refage=%lld, age=%lld\n", refresh_age, age); if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { switch (cache_make_upcall(detail, h)) { @@ -1404,7 +1404,7 @@ static int c_show(struct seq_file *m, void *p) return cd->cache_show(m, cd, NULL); ifdebug(CACHE) - seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", + seq_printf(m, "# expiry=%lld refcnt=%d flags=%lx\n", convert_to_wallclock(cp->expiry_time), kref_read(&cp->ref), cp->flags); cache_get(cp); @@ -1477,7 +1477,7 @@ static ssize_t read_flush(struct file *file, char __user *buf, char tbuf[22]; size_t len; - len = snprintf(tbuf, sizeof(tbuf), "%lu\n", + len = snprintf(tbuf, sizeof(tbuf), "%llu\n", convert_to_wallclock(cd->flush_time)); return simple_read_from_buffer(buf, count, ppos, tbuf, len); } @@ -1488,7 +1488,7 @@ static ssize_t write_flush(struct file *file, const char __user *buf, { char tbuf[20]; char *ep; - time_t now; + time64_t now; if (*ppos || count > sizeof(tbuf)-1) return -EINVAL; |