From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [PATCH 10/25] aio: do fget() after aio_get_req() Date: Wed, 28 Nov 2012 08:43:34 -0800 Message-ID: <1354121029-1376-11-git-send-email-koverstreet@google.com> References: <1354121029-1376-1-git-send-email-koverstreet@google.com> Cc: zab@redhat.com, bcrl@kvack.org, jmoyer@redhat.com, axboe@kernel.dk, viro@zeniv.linux.org.uk, Kent Overstreet To: linux-kernel@vger.kernel.org, linux-aio@kvack.org, linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1354121029-1376-1-git-send-email-koverstreet@google.com> Sender: owner-linux-aio@kvack.org List-Id: linux-fsdevel.vger.kernel.org aio_get_req() will fail if we have the maximum number of requests outstanding, which depending on the application may not be uncommon. So avoid doing an unnecessary fget(). Signed-off-by: Kent Overstreet --- fs/aio.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 0ed14e8..200abff 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -583,6 +583,8 @@ static inline void really_put_req(struct kioctx *ctx, struct kiocb *req) { assert_spin_locked(&ctx->ctx_lock); + if (req->ki_filp) + fput(req->ki_filp); if (req->ki_eventfd != NULL) eventfd_ctx_put(req->ki_eventfd); if (req->ki_dtor) @@ -601,9 +603,6 @@ static inline void really_put_req(struct kioctx *ctx, struct kiocb *req) */ static void __aio_put_req(struct kioctx *ctx, struct kiocb *req) { - pr_debug("(%p): f_count=%ld\n", - req, atomic_long_read(&req->ki_filp->f_count)); - assert_spin_locked(&ctx->ctx_lock); req->ki_users--; @@ -614,8 +613,6 @@ static void __aio_put_req(struct kioctx *ctx, struct kiocb *req) req->ki_cancel = NULL; req->ki_retry = NULL; - fput(req->ki_filp); - req->ki_filp = NULL; really_put_req(ctx, req); } @@ -1265,7 +1262,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, bool compat) { struct kiocb *req; - struct file *file; ssize_t ret; /* enforce forwards compatibility on users */ @@ -1284,16 +1280,16 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, return -EINVAL; } - file = fget(iocb->aio_fildes); - if (unlikely(!file)) - return -EBADF; - req = aio_get_req(ctx, batch); /* returns with 2 references to req */ - if (unlikely(!req)) { - fput(file); + if (unlikely(!req)) return -EAGAIN; + + req->ki_filp = fget(iocb->aio_fildes); + if (unlikely(!req->ki_filp)) { + ret = -EBADF; + goto out_put_req; } - req->ki_filp = file; + if (iocb->aio_flags & IOCB_FLAG_RESFD) { /* * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an -- 1.7.12 -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org