diff options
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 38 |
1 files changed, 32 insertions, 6 deletions
@@ -29,6 +29,7 @@ #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> @@ -499,7 +500,7 @@ 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(atomic_dec_and_test(&req->ki_filp->f_count))) { + if (unlikely(rcuref_dec_and_test(&req->ki_filp->f_count))) { get_ioctx(ctx); spin_lock(&fput_lock); list_add(&req->ki_list, &fput_head); @@ -546,6 +547,24 @@ struct kioctx *lookup_ioctx(unsigned long ctx_id) return ioctx; } +static int lock_kiocb_action(void *param) +{ + schedule(); + return 0; +} + +static inline void lock_kiocb(struct kiocb *iocb) +{ + wait_on_bit_lock(&iocb->ki_flags, KIF_LOCKED, lock_kiocb_action, + TASK_UNINTERRUPTIBLE); +} + +static inline void unlock_kiocb(struct kiocb *iocb) +{ + kiocbClearLocked(iocb); + wake_up_bit(&iocb->ki_flags, KIF_LOCKED); +} + /* * use_mm * Makes the calling kernel thread take on the specified @@ -567,6 +586,10 @@ static void use_mm(struct mm_struct *mm) atomic_inc(&mm->mm_count); tsk->mm = mm; tsk->active_mm = mm; + /* + * Note that on UML this *requires* PF_BORROWED_MM to be set, otherwise + * it won't work. Update it accordingly if you change it here + */ activate_mm(active_mm, mm); task_unlock(tsk); @@ -782,7 +805,9 @@ static int __aio_run_iocbs(struct kioctx *ctx) * Hold an extra reference while retrying i/o. */ iocb->ki_users++; /* grab extra reference */ + lock_kiocb(iocb); aio_run_iocb(iocb); + unlock_kiocb(iocb); if (__aio_put_req(ctx, iocb)) /* drop extra ref */ put_ioctx(ctx); } @@ -1523,10 +1548,9 @@ int fastcall io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, goto out_put_req; spin_lock_irq(&ctx->ctx_lock); - if (likely(list_empty(&ctx->run_list))) { - aio_run_iocb(req); - } else { - list_add_tail(&req->ki_run_list, &ctx->run_list); + aio_run_iocb(req); + unlock_kiocb(req); + if (!list_empty(&ctx->run_list)) { /* drain the run list */ while (__aio_run_iocbs(ctx)) ; @@ -1657,6 +1681,7 @@ asmlinkage long sys_io_cancel(aio_context_t ctx_id, struct iocb __user *iocb, if (NULL != cancel) { struct io_event tmp; pr_debug("calling cancel\n"); + lock_kiocb(kiocb); memset(&tmp, 0, sizeof(tmp)); tmp.obj = (u64)(unsigned long)kiocb->ki_obj.user; tmp.data = kiocb->ki_user_data; @@ -1668,8 +1693,9 @@ asmlinkage long sys_io_cancel(aio_context_t ctx_id, struct iocb __user *iocb, if (copy_to_user(result, &tmp, sizeof(tmp))) ret = -EFAULT; } + unlock_kiocb(kiocb); } else - printk(KERN_DEBUG "iocb has no cancel operation\n"); + ret = -EINVAL; put_ioctx(ctx); |