[PATCH 06/32] aio: simplify KIOCB_KEY handling
From: Christoph Hellwig <hch@lst.de>
Date: 2018-03-30 15:34:10
Also in:
linux-fsdevel, lkml, netdev
Subsystem:
aio, filesystems (vfs and infrastructure), the rest · Maintainers:
Benjamin LaHaise, Alexander Viro, Christian Brauner, Linus Torvalds
No need to pass the key field to lookup_iocb to compare it with KIOCB_KEY, as we can do that right after retrieving it from userspace. Also move the KIOCB_KEY definition to aio.c as it is an internal value not used by any other place in the kernel. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/aio.c | 14 +++++++------- include/linux/aio.h | 2 -- 2 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index 0df07d399a05..cec42b4e3c3a 100644
--- a/fs/aio.c
+++ b/fs/aio.c@@ -46,6 +46,8 @@ #include "internal.h" +#define KIOCB_KEY 0 + #define AIO_RING_MAGIC 0xa10a10a1 #define AIO_RING_COMPAT_FEATURES 1 #define AIO_RING_INCOMPAT_FEATURES 0
@@ -1805,15 +1807,12 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id, * Finds a given iocb for cancellation. */ static struct aio_kiocb * -lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, u32 key) +lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb) { struct aio_kiocb *kiocb; assert_spin_locked(&ctx->ctx_lock); - if (key != KIOCB_KEY) - return NULL; - /* TODO: use a hash or array, this sucks. */ list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) { if (kiocb->ki_user_iocb == iocb)
@@ -1840,9 +1839,10 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, u32 key; int ret; - ret = get_user(key, &iocb->aio_key); - if (unlikely(ret)) + if (unlikely(get_user(key, &iocb->aio_key))) return -EFAULT; + if (unlikely(key != KIOCB_KEY)) + return -EINVAL; ctx = lookup_ioctx(ctx_id); if (unlikely(!ctx))
@@ -1850,7 +1850,7 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, spin_lock_irq(&ctx->ctx_lock); - kiocb = lookup_kiocb(ctx, iocb, key); + kiocb = lookup_kiocb(ctx, iocb); if (kiocb) ret = kiocb_cancel(kiocb); else
diff --git a/include/linux/aio.h b/include/linux/aio.h
index 9d8aabecfe2d..b83e68dd006f 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h@@ -8,8 +8,6 @@ struct kioctx; struct kiocb; struct mm_struct; -#define KIOCB_KEY 0 - typedef int (kiocb_cancel_fn)(struct kiocb *); /* prototypes */
--
2.14.2
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