diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/aio.c | 31 |
1 files changed, 21 insertions, 10 deletions
@@ -42,8 +42,9 @@ #endif /*------ sysctl variables----*/ -atomic_t aio_nr = ATOMIC_INIT(0); /* current system wide number of aio requests */ -unsigned aio_max_nr = 0x10000; /* system wide maximum number of aio requests */ +static DEFINE_SPINLOCK(aio_nr_lock); +unsigned long aio_nr; /* current system wide number of aio requests */ +unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */ /*----end sysctl variables---*/ static kmem_cache_t *kiocb_cachep; @@ -208,7 +209,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) return ERR_PTR(-EINVAL); } - if (nr_events > aio_max_nr) + if ((unsigned long)nr_events > aio_max_nr) return ERR_PTR(-EAGAIN); ctx = kmem_cache_alloc(kioctx_cachep, GFP_KERNEL); @@ -233,8 +234,14 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) goto out_freectx; /* limit the number of system wide aios */ - atomic_add(ctx->max_reqs, &aio_nr); /* undone by __put_ioctx */ - if (unlikely(atomic_read(&aio_nr) > aio_max_nr)) + spin_lock(&aio_nr_lock); + if (aio_nr + ctx->max_reqs > aio_max_nr || + aio_nr + ctx->max_reqs < aio_nr) + ctx->max_reqs = 0; + else + aio_nr += ctx->max_reqs; + spin_unlock(&aio_nr_lock); + if (ctx->max_reqs == 0) goto out_cleanup; /* now link into global list. kludge. FIXME */ @@ -248,8 +255,6 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) return ctx; out_cleanup: - atomic_sub(ctx->max_reqs, &aio_nr); - ctx->max_reqs = 0; /* prevent __put_ioctx from sub'ing aio_nr */ __put_ioctx(ctx); return ERR_PTR(-EAGAIN); @@ -374,7 +379,12 @@ void fastcall __put_ioctx(struct kioctx *ctx) pr_debug("__put_ioctx: freeing %p\n", ctx); kmem_cache_free(kioctx_cachep, ctx); - atomic_sub(nr_events, &aio_nr); + if (nr_events) { + spin_lock(&aio_nr_lock); + BUG_ON(aio_nr - nr_events > aio_nr); + aio_nr -= nr_events; + spin_unlock(&aio_nr_lock); + } } /* aio_get_req @@ -1258,8 +1268,9 @@ asmlinkage long sys_io_setup(unsigned nr_events, aio_context_t __user *ctxp) goto out; ret = -EINVAL; - if (unlikely(ctx || (int)nr_events <= 0)) { - pr_debug("EINVAL: io_setup: ctx or nr_events > max\n"); + if (unlikely(ctx || nr_events == 0)) { + pr_debug("EINVAL: io_setup: ctx %lu nr_events %u\n", + ctx, nr_events); goto out; } |