diff options
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 47 |
1 files changed, 22 insertions, 25 deletions
@@ -29,7 +29,6 @@ #include <linux/highmem.h> #include <linux/workqueue.h> #include <linux/security.h> -#include <linux/rcuref.h> #include <asm/kmap_types.h> #include <asm/uaccess.h> @@ -457,6 +456,8 @@ static inline struct kiocb *aio_get_req(struct kioctx *ctx) static inline void really_put_req(struct kioctx *ctx, struct kiocb *req) { + assert_spin_locked(&ctx->ctx_lock); + if (req->ki_dtor) req->ki_dtor(req); kmem_cache_free(kiocb_cachep, req); @@ -498,6 +499,8 @@ static int __aio_put_req(struct kioctx *ctx, struct kiocb *req) dprintk(KERN_DEBUG "aio_put(%p): f_count=%d\n", req, atomic_read(&req->ki_filp->f_count)); + assert_spin_locked(&ctx->ctx_lock); + req->ki_users --; if (unlikely(req->ki_users < 0)) BUG(); @@ -510,7 +513,7 @@ static int __aio_put_req(struct kioctx *ctx, struct kiocb *req) /* Must be done under the lock to serialise against cancellation. * Call this aio_fput as it duplicates fput via the fput_work. */ - if (unlikely(rcuref_dec_and_test(&req->ki_filp->f_count))) { + if (unlikely(atomic_dec_and_test(&req->ki_filp->f_count))) { get_ioctx(ctx); spin_lock(&fput_lock); list_add(&req->ki_list, &fput_head); @@ -619,14 +622,13 @@ static void unuse_mm(struct mm_struct *mm) * the kiocb (to tell the caller to activate the work * queue to process it), or 0, if it found that it was * already queued. - * - * Should be called with the spin lock iocb->ki_ctx->ctx_lock - * held */ static inline int __queue_kicked_iocb(struct kiocb *iocb) { struct kioctx *ctx = iocb->ki_ctx; + assert_spin_locked(&ctx->ctx_lock); + if (list_empty(&iocb->ki_run_list)) { list_add_tail(&iocb->ki_run_list, &ctx->run_list); @@ -771,13 +773,15 @@ out: * Process all pending retries queued on the ioctx * run list. * Assumes it is operating within the aio issuer's mm - * context. Expects to be called with ctx->ctx_lock held + * context. */ static int __aio_run_iocbs(struct kioctx *ctx) { struct kiocb *iocb; LIST_HEAD(run_list); + assert_spin_locked(&ctx->ctx_lock); + list_splice_init(&ctx->run_list, &run_list); while (!list_empty(&run_list)) { iocb = list_entry(run_list.next, struct kiocb, @@ -937,28 +941,19 @@ int fastcall aio_complete(struct kiocb *iocb, long res, long res2) unsigned long tail; int ret; - /* Special case handling for sync iocbs: events go directly - * into the iocb for fast handling. Note that this will not - * work if we allow sync kiocbs to be cancelled. in which - * case the usage count checks will have to move under ctx_lock - * for all cases. + /* + * Special case handling for sync iocbs: + * - events go directly into the iocb for fast handling + * - the sync task with the iocb in its stack holds the single iocb + * ref, no other paths have a way to get another ref + * - the sync task helpfully left a reference to itself in the iocb */ if (is_sync_kiocb(iocb)) { - int ret; - + BUG_ON(iocb->ki_users != 1); iocb->ki_user_data = res; - if (iocb->ki_users == 1) { - iocb->ki_users = 0; - ret = 1; - } else { - spin_lock_irq(&ctx->ctx_lock); - iocb->ki_users--; - ret = (0 == iocb->ki_users); - spin_unlock_irq(&ctx->ctx_lock); - } - /* sync iocbs put the task here for us */ + iocb->ki_users = 0; wake_up_process(iocb->ki_obj.tsk); - return ret; + return 1; } info = &ctx->ring_info; @@ -1613,12 +1608,14 @@ asmlinkage long sys_io_submit(aio_context_t ctx_id, long nr, /* lookup_kiocb * Finds a given iocb for cancellation. - * MUST be called with ctx->ctx_lock held. */ static struct kiocb *lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, u32 key) { struct list_head *pos; + + assert_spin_locked(&ctx->ctx_lock); + /* TODO: use a hash or array, this sucks. */ list_for_each(pos, &ctx->active_reqs) { struct kiocb *kiocb = list_kiocb(pos); |