diff options
| author | Benjamin LaHaise <bcrl@linux.intel.com> | 2005-09-09 22:02:09 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-09 22:57:32 +0200 |
| commit | ac0b1bc1edbe81c0cb36cad7e7f5b91f4d9e12ed (patch) | |
| tree | b982e728eafeebc226882f91482ff7d0d9ee5cc3 /fs | |
| parent | [PATCH] change io_cancel return code for no cancel case (diff) | |
| download | linux-ac0b1bc1edbe81c0cb36cad7e7f5b91f4d9e12ed.tar.xz linux-ac0b1bc1edbe81c0cb36cad7e7f5b91f4d9e12ed.zip | |
[PATCH] aio: kiocb locking to serialise retry and cancel
Implement a per-kiocb lock to serialise retry operations and cancel. This
is done using wait_on_bit_lock() on the KIF_LOCKED bit of kiocb->ki_flags.
Also, make the cancellation path lock the kiocb and subsequently release
all references to it if the cancel was successful. This version includes a
fix for the deadlock with __aio_run_iocbs.
Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/aio.c | 29 |
1 files changed, 25 insertions, 4 deletions
@@ -546,6 +546,24 @@ 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 @@ -786,7 +804,9 @@ 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); } @@ -1527,10 +1547,9 @@ 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)) ; @@ -1661,6 +1680,7 @@ 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; @@ -1672,6 +1692,7 @@ 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 ret = -EINVAL; |