[PATCH v3] fs/aio.c: Cosmetic

From: Alejandro Colomar
Date: Tue Nov 03 2020 - 04:50:56 EST

Changes:
- Consistently use 'unsigned int', instead of 'unsigned'.
- Add a blank line after variable declarations.
- Move variable declarations to the top of functions.
- Invert logic of 'if's to reduce indentation and simplify function logic.
- Add goto tags when needed.
- Early return when appropriate.
- Add braces to 'else' if the corresponding 'if' used braces.
- Replace spaces by tabs
- Add spaces when appropriate (after comma, around operators, ...).
- Split multiple assignments.
- Align function arguments.
- Fix typos in comments.
- s/%Lx/%llx/ Standard C uses 'll'.
- Remove trailing whitespace in comments.

This patch does not introduce any actual changes in behavior.

Signed-off-by: Alejandro Colomar <colomar.6.4.3@xxxxxxxxx>
---

Hi,

On 2020-11-03 04:22, Joe Perches wrote:
> On Mon, 2020-11-02 at 17:50 -0700, Andreas Dilger wrote:
>> On Nov 2, 2020, at 2:58 PM, Alejandro Colomar <colomar.6.4.3@xxxxxxxxx> wrote:
>>> Changes:
>>> - Consistently use 'unsigned int', instead of 'unsigned'.
>>> - Add a blank line after variable declarations.
>>> - Move variable declarations to the top of functions.
>>> - Add a blank line at the top of functions if there are no declarations.
>>
>> I'd agree that the other changes are following kernel coding style, but
>> I've never heard of leaving a blank line at the start of functions without
>> any local variables.
>
> I think that is odd as well.

Ooops, it's funny, I was almost sure I had read it,
but my imagination seems to be taking control over me :p

Anyway, I fixed it now.

>
>> I don't see anything in process/coding-style.rst to
>> support this change, nor are the majority of variable-less functions
>> formatted this way, and it seems to just be a waste of vertical space.
>
> checkpatch emits a --strict CHECK for those blank lines after
> open braces
[...]

I now passed checkpatch to fs/aio.c and
found a few more things to fix in that file.
There are still a few warnings, but I fixed most of them.

Thanks,

Alex

fs/aio.c | 466 +++++++++++++++++++++++++++++--------------------------
1 file changed, 243 insertions(+), 223 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index c45c20d87538..5b567d8f56e3 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -55,17 +55,16 @@
#define AIO_RING_COMPAT_FEATURES 1
#define AIO_RING_INCOMPAT_FEATURES 0
struct aio_ring {
- unsigned id; /* kernel internal index number */
- unsigned nr; /* number of io_events */
- unsigned head; /* Written to by userland or under ring_lock
+ unsigned int id; /* kernel internal index number */
+ unsigned int nr; /* number of io_events */
+ unsigned int head; /* Written to by userland or under ring_lock
* mutex by aio_read_events_ring(). */
- unsigned tail;
-
- unsigned magic;
- unsigned compat_features;
- unsigned incompat_features;
- unsigned header_length; /* size of aio_ring */
+ unsigned int tail;

+ unsigned int magic;
+ unsigned int compat_features;
+ unsigned int incompat_features;
+ unsigned int header_length; /* size of aio_ring */

struct io_event io_events[];
}; /* 128 bytes + ring size */
@@ -80,12 +79,12 @@ struct aio_ring {

struct kioctx_table {
struct rcu_head rcu;
- unsigned nr;
+ unsigned int nr;
struct kioctx __rcu *table[];
};

struct kioctx_cpu {
- unsigned reqs_available;
+ unsigned int reqs_available;
};

struct ctx_rq_wait {
@@ -107,7 +106,7 @@ struct kioctx {
* For percpu reqs_available, number of slots we move to/from global
* counter at a time:
*/
- unsigned req_batch;
+ unsigned int req_batch;
/*
* This is what userspace passed to io_setup(), it's not used for
* anything but counting against the global max_reqs quota.
@@ -115,10 +114,10 @@ struct kioctx {
* The real limit is nr_events - 1, which will be larger (see
* aio_setup_ring())
*/
- unsigned max_reqs;
+ unsigned int max_reqs;

/* Size of ringbuffer, in units of struct io_event */
- unsigned nr_events;
+ unsigned int nr_events;

unsigned long mmap_base;
unsigned long mmap_size;
@@ -156,15 +155,15 @@ struct kioctx {
} ____cacheline_aligned_in_smp;

struct {
- unsigned tail;
- unsigned completed_events;
+ unsigned int tail;
+ unsigned int completed_events;
spinlock_t completion_lock;
} ____cacheline_aligned_in_smp;

struct page *internal_pages[AIO_RING_PAGES];
struct file *aio_ring_file;

- unsigned id;
+ unsigned int id;
};

/*
@@ -236,6 +235,7 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
{
struct file *file;
struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
+
if (IS_ERR(inode))
return ERR_CAST(inode);

@@ -269,12 +269,13 @@ static int __init aio_setup(void)
.init_fs_context = aio_init_fs_context,
.kill_sb = kill_anon_super,
};
+
aio_mnt = kern_mount(&aio_fs);
if (IS_ERR(aio_mnt))
panic("Failed to create aio fs mount.");

- kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
- kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
+ kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
+ kioctx_cachep = KMEM_CACHE(kioctx, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
return 0;
}
__initcall(aio_setup);
@@ -284,18 +285,19 @@ static void put_aio_ring_file(struct kioctx *ctx)
struct file *aio_ring_file = ctx->aio_ring_file;
struct address_space *i_mapping;

- if (aio_ring_file) {
- truncate_setsize(file_inode(aio_ring_file), 0);
+ if (!aio_ring_file)
+ return;

- /* Prevent further access to the kioctx from migratepages */
- i_mapping = aio_ring_file->f_mapping;
- spin_lock(&i_mapping->private_lock);
- i_mapping->private_data = NULL;
- ctx->aio_ring_file = NULL;
- spin_unlock(&i_mapping->private_lock);
+ truncate_setsize(file_inode(aio_ring_file), 0);

- fput(aio_ring_file);
- }
+ /* Prevent further access to the kioctx from migratepages */
+ i_mapping = aio_ring_file->f_mapping;
+ spin_lock(&i_mapping->private_lock);
+ i_mapping->private_data = NULL;
+ ctx->aio_ring_file = NULL;
+ spin_unlock(&i_mapping->private_lock);
+
+ fput(aio_ring_file);
}

static void aio_free_ring(struct kioctx *ctx)
@@ -309,6 +311,7 @@ static void aio_free_ring(struct kioctx *ctx)

for (i = 0; i < ctx->nr_pages; i++) {
struct page *page;
+
pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
page_count(ctx->ring_pages[i]));
page = ctx->ring_pages[i];
@@ -340,7 +343,8 @@ static int aio_ring_mremap(struct vm_area_struct *vma)
ctx = rcu_dereference(table->table[i]);
if (ctx && ctx->aio_ring_file == file) {
if (!atomic_read(&ctx->dead)) {
- ctx->user_id = ctx->mmap_base = vma->vm_start;
+ ctx->mmap_base = vma->vm_start;
+ ctx->user_id = vma->vm_start;
res = 0;
}
break;
@@ -374,7 +378,7 @@ static const struct file_operations aio_ring_fops = {

#if IS_ENABLED(CONFIG_MIGRATION)
static int aio_migratepage(struct address_space *mapping, struct page *new,
- struct page *old, enum migrate_mode mode)
+ struct page *old, enum migrate_mode mode)
{
struct kioctx *ctx;
unsigned long flags;
@@ -413,8 +417,9 @@ static int aio_migratepage(struct address_space *mapping, struct page *new,
/* Make sure the old page hasn't already been changed */
if (ctx->ring_pages[idx] != old)
rc = -EAGAIN;
- } else
+ } else {
rc = -EINVAL;
+ }

if (rc != 0)
goto out_unlock;
@@ -498,6 +503,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)

for (i = 0; i < nr_pages; i++) {
struct page *page;
+
page = find_or_create_page(file->f_mapping,
i, GFP_HIGHUSER | __GFP_ZERO);
if (!page)
@@ -543,7 +549,8 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
ring = kmap_atomic(ctx->ring_pages[0]);
ring->nr = nr_events; /* user copy */
ring->id = ~0U;
- ring->head = ring->tail = 0;
+ ring->tail = 0;
+ ring->head = 0;
ring->magic = AIO_RING_MAGIC;
ring->compat_features = AIO_RING_COMPAT_FEATURES;
ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
@@ -632,7 +639,7 @@ static void free_ioctx_users(struct percpu_ref *ref)

static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
{
- unsigned i, new_nr;
+ unsigned int i, new_nr;
struct kioctx_table *table, *old;
struct aio_ring *ring;

@@ -640,23 +647,27 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
table = rcu_dereference_raw(mm->ioctx_table);

while (1) {
- if (table)
- for (i = 0; i < table->nr; i++)
- if (!rcu_access_pointer(table->table[i])) {
- ctx->id = i;
- rcu_assign_pointer(table->table[i], ctx);
- spin_unlock(&mm->ioctx_lock);
-
- /* While kioctx setup is in progress,
- * we are protected from page migration
- * changes ring_pages by ->ring_lock.
- */
- ring = kmap_atomic(ctx->ring_pages[0]);
- ring->id = ctx->id;
- kunmap_atomic(ring);
- return 0;
- }
-
+ if (!table)
+ goto new_table;
+
+ for (i = 0; i < table->nr; i++) {
+ if (rcu_access_pointer(table->table[i]))
+ continue;
+
+ ctx->id = i;
+ rcu_assign_pointer(table->table[i], ctx);
+ spin_unlock(&mm->ioctx_lock);
+
+ /* While kioctx setup is in progress,
+ * we are protected from page migration
+ * changes ring_pages by ->ring_lock.
+ */
+ ring = kmap_atomic(ctx->ring_pages[0]);
+ ring->id = ctx->id;
+ kunmap_atomic(ring);
+ return 0;
+ }
+new_table:
new_nr = (table ? table->nr : 1) * 4;
spin_unlock(&mm->ioctx_lock);

@@ -685,7 +696,7 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
}
}

-static void aio_nr_sub(unsigned nr)
+static void aio_nr_sub(unsigned int nr)
{
spin_lock(&aio_nr_lock);
if (WARN_ON(aio_nr - nr > aio_nr))
@@ -698,7 +709,7 @@ static void aio_nr_sub(unsigned nr)
/* ioctx_alloc
* Allocates and initializes an ioctx. Returns an ERR_PTR if it failed.
*/
-static struct kioctx *ioctx_alloc(unsigned nr_events)
+static struct kioctx *ioctx_alloc(unsigned int nr_events)
{
struct mm_struct *mm = current->mm;
struct kioctx *ctx;
@@ -851,7 +862,7 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,

/*
* exit_aio: called when the last user of mm goes away. At this point, there is
- * no way for any new requests to be submited or any of the io_* syscalls to be
+ * no way for any new requests to be submitted or any of the io_* syscalls to be
* called on the context.
*
* There may be outstanding kiocbs, but free_ioctx() will explicitly wait on
@@ -899,7 +910,7 @@ void exit_aio(struct mm_struct *mm)
kfree(table);
}

-static void put_reqs_available(struct kioctx *ctx, unsigned nr)
+static void put_reqs_available(struct kioctx *ctx, unsigned int nr)
{
struct kioctx_cpu *kcpu;
unsigned long flags;
@@ -921,24 +932,27 @@ static bool __get_reqs_available(struct kioctx *ctx)
struct kioctx_cpu *kcpu;
bool ret = false;
unsigned long flags;
+ int old, avail;

local_irq_save(flags);
kcpu = this_cpu_ptr(ctx->cpu);
- if (!kcpu->reqs_available) {
- int old, avail = atomic_read(&ctx->reqs_available);
+ if (kcpu->reqs_available)
+ goto kcpu_reqs_avail;

- do {
- if (avail < ctx->req_batch)
- goto out;
+ avail = atomic_read(&ctx->reqs_available);

- old = avail;
- avail = atomic_cmpxchg(&ctx->reqs_available,
- avail, avail - ctx->req_batch);
- } while (avail != old);
+ do {
+ if (avail < ctx->req_batch)
+ goto out;

- kcpu->reqs_available += ctx->req_batch;
- }
+ old = avail;
+ avail = atomic_cmpxchg(&ctx->reqs_available,
+ avail, avail - ctx->req_batch);
+ } while (avail != old);

+ kcpu->reqs_available += ctx->req_batch;
+
+kcpu_reqs_avail:
ret = true;
kcpu->reqs_available--;
out:
@@ -953,10 +967,10 @@ static bool __get_reqs_available(struct kioctx *ctx)
* from aio_get_req() (the we're out of events case). It must be
* called holding ctx->completion_lock.
*/
-static void refill_reqs_available(struct kioctx *ctx, unsigned head,
- unsigned tail)
+static void refill_reqs_available(struct kioctx *ctx, unsigned int head,
+ unsigned int tail)
{
- unsigned events_in_ring, completed;
+ unsigned int events_in_ring, completed;

/* Clamp head since userland can write to it. */
head %= ctx->nr_events;
@@ -984,27 +998,28 @@ static void refill_reqs_available(struct kioctx *ctx, unsigned head,
*/
static void user_refill_reqs_available(struct kioctx *ctx)
{
+ struct aio_ring *ring;
+ unsigned int head;
+
spin_lock_irq(&ctx->completion_lock);
- if (ctx->completed_events) {
- struct aio_ring *ring;
- unsigned head;
-
- /* Access of ring->head may race with aio_read_events_ring()
- * here, but that's okay since whether we read the old version
- * or the new version, and either will be valid. The important
- * part is that head cannot pass tail since we prevent
- * aio_complete() from updating tail by holding
- * ctx->completion_lock. Even if head is invalid, the check
- * against ctx->completed_events below will make sure we do the
- * safe/right thing.
- */
- ring = kmap_atomic(ctx->ring_pages[0]);
- head = ring->head;
- kunmap_atomic(ring);
+ if (!ctx->completed_events)
+ goto out;

- refill_reqs_available(ctx, head, ctx->tail);
- }
+ /* Access of ring->head may race with aio_read_events_ring()
+ * here, but that's okay since whether we read the old version
+ * or the new version, and either will be valid. The important
+ * part is that head cannot pass tail since we prevent
+ * aio_complete() from updating tail by holding
+ * ctx->completion_lock. Even if head is invalid, the check
+ * against ctx->completed_events below will make sure we do the
+ * safe/right thing.
+ */
+ ring = kmap_atomic(ctx->ring_pages[0]);
+ head = ring->head;
+ kunmap_atomic(ring);

+ refill_reqs_available(ctx, head, ctx->tail);
+out:
spin_unlock_irq(&ctx->completion_lock);
}

@@ -1050,7 +1065,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
struct mm_struct *mm = current->mm;
struct kioctx *ctx, *ret = NULL;
struct kioctx_table *table;
- unsigned id;
+ unsigned int id;

if (get_user(id, &ring->id))
return NULL;
@@ -1090,7 +1105,7 @@ static void aio_complete(struct aio_kiocb *iocb)
struct kioctx *ctx = iocb->ki_ctx;
struct aio_ring *ring;
struct io_event *ev_page, *event;
- unsigned tail, pos, head;
+ unsigned int tail, pos, head;
unsigned long flags;

/*
@@ -1114,7 +1129,7 @@ static void aio_complete(struct aio_kiocb *iocb)
kunmap_atomic(ev_page);
flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);

- pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb,
+ pr_debug("%p[%u]: %p: %p %llx %llx %llx\n", ctx, tail, iocb,
(void __user *)(unsigned long)iocb->ki_res.obj,
iocb->ki_res.data, iocb->ki_res.res, iocb->ki_res.res2);

@@ -1160,10 +1175,10 @@ static void aio_complete(struct aio_kiocb *iocb)

static inline void iocb_put(struct aio_kiocb *iocb)
{
- if (refcount_dec_and_test(&iocb->ki_refcnt)) {
- aio_complete(iocb);
- iocb_destroy(iocb);
- }
+ if (!refcount_dec_and_test(&iocb->ki_refcnt))
+ return;
+ aio_complete(iocb);
+ iocb_destroy(iocb);
}

/* aio_read_events_ring
@@ -1174,7 +1189,7 @@ static long aio_read_events_ring(struct kioctx *ctx,
struct io_event __user *event, long nr)
{
struct aio_ring *ring;
- unsigned head, tail, pos;
+ unsigned int head, tail, pos;
long ret = 0;
int copy_ret;

@@ -1182,7 +1197,7 @@ static long aio_read_events_ring(struct kioctx *ctx,
* The mutex can block and wake us up and that will cause
* wait_event_interruptible_hrtimeout() to schedule without sleeping
* and repeat. This should be rare enough that it doesn't cause
- * peformance issues. See the comment in read_events() for more detail.
+ * performance issues. See the comment in read_events() for more detail.
*/
sched_annotate_sleep();
mutex_lock(&ctx->ring_lock);
@@ -1300,16 +1315,16 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
* Create an aio_context capable of receiving at least nr_events.
* ctxp must not point to an aio_context that already exists, and
* must be initialized to 0 prior to the call. On successful
- * creation of the aio_context, *ctxp is filled in with the resulting
+ * creation of the aio_context, *ctxp is filled in with the resulting
* handle. May fail with -EINVAL if *ctxp is not initialized,
- * if the specified nr_events exceeds internal limits. May fail
- * with -EAGAIN if the specified nr_events exceeds the user's limit
+ * if the specified nr_events exceeds internal limits. May fail
+ * with -EAGAIN if the specified nr_events exceeds the user's limit
* of available events. May fail with -ENOMEM if insufficient kernel
* resources are available. May fail with -EFAULT if an invalid
* pointer is passed for ctxp. Will fail with -ENOSYS if not
* implemented.
*/
-SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
+SYSCALL_DEFINE2(io_setup, unsigned int, nr_events, aio_context_t __user *, ctxp)
{
struct kioctx *ioctx = NULL;
unsigned long ctx;
@@ -1321,26 +1336,25 @@ SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)

ret = -EINVAL;
if (unlikely(ctx || nr_events == 0)) {
- pr_debug("EINVAL: ctx %lu nr_events %u\n",
- ctx, nr_events);
+ pr_debug("EINVAL: ctx %lu nr_events %u\n", ctx, nr_events);
goto out;
}

ioctx = ioctx_alloc(nr_events);
ret = PTR_ERR(ioctx);
- if (!IS_ERR(ioctx)) {
- ret = put_user(ioctx->user_id, ctxp);
- if (ret)
- kill_ioctx(current->mm, ioctx, NULL);
- percpu_ref_put(&ioctx->users);
- }
+ if (IS_ERR(ioctx))
+ goto out;
+ ret = put_user(ioctx->user_id, ctxp);
+ if (ret)
+ kill_ioctx(current->mm, ioctx, NULL);
+ percpu_ref_put(&ioctx->users);

out:
return ret;
}

#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
+COMPAT_SYSCALL_DEFINE2(io_setup, unsigned int, nr_events, u32 __user *, ctx32p)
{
struct kioctx *ioctx = NULL;
unsigned long ctx;
@@ -1352,20 +1366,19 @@ COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)

ret = -EINVAL;
if (unlikely(ctx || nr_events == 0)) {
- pr_debug("EINVAL: ctx %lu nr_events %u\n",
- ctx, nr_events);
+ pr_debug("EINVAL: ctx %lu nr_events %u\n", ctx, nr_events);
goto out;
}

ioctx = ioctx_alloc(nr_events);
ret = PTR_ERR(ioctx);
- if (!IS_ERR(ioctx)) {
- /* truncating is ok because it's a user address */
- ret = put_user((u32)ioctx->user_id, ctx32p);
- if (ret)
- kill_ioctx(current->mm, ioctx, NULL);
- percpu_ref_put(&ioctx->users);
- }
+ if (IS_ERR(ioctx))
+ goto out;
+ /* truncating is ok because it's a user address */
+ ret = put_user((u32)ioctx->user_id, ctx32p);
+ if (ret)
+ kill_ioctx(current->mm, ioctx, NULL);
+ percpu_ref_put(&ioctx->users);

out:
return ret;
@@ -1373,7 +1386,7 @@ COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
#endif

/* sys_io_destroy:
- * Destroy the aio_context specified. May cancel any outstanding
+ * Destroy the aio_context specified. May cancel any outstanding
* AIOs and block on completion. Will fail with -ENOSYS if not
* implemented. May fail with -EINVAL if the context pointed to
* is invalid.
@@ -1381,31 +1394,32 @@ COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
{
struct kioctx *ioctx = lookup_ioctx(ctx);
- if (likely(NULL != ioctx)) {
- struct ctx_rq_wait wait;
- int ret;
+ struct ctx_rq_wait wait;
+ int ret;

- init_completion(&wait.comp);
- atomic_set(&wait.count, 1);
+ if (unlikely(!ioctx)) {
+ pr_debug("EINVAL: invalid context id\n");
+ return -EINVAL;
+ }

- /* Pass requests_done to kill_ioctx() where it can be set
- * in a thread-safe way. If we try to set it here then we have
- * a race condition if two io_destroy() called simultaneously.
- */
- ret = kill_ioctx(current->mm, ioctx, &wait);
- percpu_ref_put(&ioctx->users);
+ init_completion(&wait.comp);
+ atomic_set(&wait.count, 1);

- /* Wait until all IO for the context are done. Otherwise kernel
- * keep using user-space buffers even if user thinks the context
- * is destroyed.
- */
- if (!ret)
- wait_for_completion(&wait.comp);
+ /* Pass requests_done to kill_ioctx() where it can be set
+ * in a thread-safe way. If we try to set it here then we have
+ * a race condition if two io_destroy() called simultaneously.
+ */
+ ret = kill_ioctx(current->mm, ioctx, &wait);
+ percpu_ref_put(&ioctx->users);

- return ret;
- }
- pr_debug("EINVAL: invalid context id\n");
- return -EINVAL;
+ /* Wait until all IO for the context are done. Otherwise kernel
+ * keep using user-space buffers even if user thinks the context
+ * is destroyed.
+ */
+ if (!ret)
+ wait_for_completion(&wait.comp);
+
+ return ret;
}

static void aio_remove_iocb(struct aio_kiocb *iocb)
@@ -1466,8 +1480,9 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
}

req->ki_ioprio = iocb->aio_reqprio;
- } else
+ } else {
req->ki_ioprio = get_current_ioprio();
+ }

ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
if (unlikely(ret))
@@ -1478,8 +1493,8 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
}

static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
- struct iovec **iovec, bool vectored, bool compat,
- struct iov_iter *iter)
+ struct iovec **iovec, bool vectored, bool compat,
+ struct iov_iter *iter)
{
void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
size_t len = iocb->aio_nbytes;
@@ -1514,7 +1529,7 @@ static inline void aio_rw_done(struct kiocb *req, ssize_t ret)
}

static int aio_read(struct kiocb *req, const struct iocb *iocb,
- bool vectored, bool compat)
+ bool vectored, bool compat)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct iov_iter iter;
@@ -1542,7 +1557,7 @@ static int aio_read(struct kiocb *req, const struct iocb *iocb,
}

static int aio_write(struct kiocb *req, const struct iocb *iocb,
- bool vectored, bool compat)
+ bool vectored, bool compat)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct iov_iter iter;
@@ -1563,21 +1578,23 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
if (ret < 0)
return ret;
ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
- if (!ret) {
- /*
- * Open-code file_start_write here to grab freeze protection,
- * which will be released by another thread in
- * aio_complete_rw(). Fool lockdep by telling it the lock got
- * released so that it doesn't complain about the held lock when
- * we return to userspace.
- */
- if (S_ISREG(file_inode(file)->i_mode)) {
- __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
- __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
- }
- req->ki_flags |= IOCB_WRITE;
- aio_rw_done(req, call_write_iter(file, req, &iter));
+ if (ret)
+ goto out;
+
+ /*
+ * Open-code file_start_write here to grab freeze protection,
+ * which will be released by another thread in
+ * aio_complete_rw(). Fool lockdep by telling it the lock got
+ * released so that it doesn't complain about the held lock when
+ * we return to userspace.
+ */
+ if (S_ISREG(file_inode(file)->i_mode)) {
+ __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+ __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
}
+ req->ki_flags |= IOCB_WRITE;
+ aio_rw_done(req, call_write_iter(file, req, &iter));
+out:
kfree(iovec);
return ret;
}
@@ -1670,13 +1687,14 @@ static int aio_poll_cancel(struct kiocb *iocb)
return 0;
}

-static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
- void *key)
+static int aio_poll_wake(struct wait_queue_entry *wait, unsigned int mode,
+ int sync, void *key)
{
struct poll_iocb *req = container_of(wait, struct poll_iocb, wait);
struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
__poll_t mask = key_to_poll(key);
unsigned long flags;
+ struct kioctx *ctx;

/* for instances that support it check for an event match first: */
if (mask && !(mask & req->events))
@@ -1684,29 +1702,31 @@ static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,

list_del_init(&req->wait.entry);

- if (mask && spin_trylock_irqsave(&iocb->ki_ctx->ctx_lock, flags)) {
- struct kioctx *ctx = iocb->ki_ctx;
+ if (!(mask && spin_trylock_irqsave(&iocb->ki_ctx->ctx_lock, flags))) {
+ schedule_work(&req->work);
+ return 1;
+ }
+
+ ctx = iocb->ki_ctx;

- /*
- * Try to complete the iocb inline if we can. Use
- * irqsave/irqrestore because not all filesystems (e.g. fuse)
- * call this function with IRQs disabled and because IRQs
- * have to be disabled before ctx_lock is obtained.
- */
- list_del(&iocb->ki_list);
- iocb->ki_res.res = mangle_poll(mask);
- req->done = true;
- if (iocb->ki_eventfd && eventfd_signal_count()) {
- iocb = NULL;
- INIT_WORK(&req->work, aio_poll_put_work);
- schedule_work(&req->work);
- }
- spin_unlock_irqrestore(&ctx->ctx_lock, flags);
- if (iocb)
- iocb_put(iocb);
- } else {
+ /*
+ * Try to complete the iocb inline if we can. Use
+ * irqsave/irqrestore because not all filesystems (e.g. fuse)
+ * call this function with IRQs disabled and because IRQs
+ * have to be disabled before ctx_lock is obtained.
+ */
+ list_del(&iocb->ki_list);
+ iocb->ki_res.res = mangle_poll(mask);
+ req->done = true;
+ if (iocb->ki_eventfd && eventfd_signal_count()) {
+ iocb = NULL;
+ INIT_WORK(&req->work, aio_poll_put_work);
schedule_work(&req->work);
}
+ spin_unlock_irqrestore(&ctx->ctx_lock, flags);
+ if (iocb)
+ iocb_put(iocb);
+
return 1;
}

@@ -1716,9 +1736,8 @@ struct aio_poll_table {
int error;
};

-static void
-aio_poll_queue_proc(struct file *file, struct wait_queue_head *head,
- struct poll_table_struct *p)
+static void aio_poll_queue_proc(struct file *file, struct wait_queue_head *head,
+ struct poll_table_struct *p)
{
struct aio_poll_table *pt = container_of(p, struct aio_poll_table, pt);

@@ -1766,24 +1785,25 @@ static int aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)

mask = vfs_poll(req->file, &apt.pt) & req->events;
spin_lock_irq(&ctx->ctx_lock);
- if (likely(req->head)) {
- spin_lock(&req->head->lock);
- if (unlikely(list_empty(&req->wait.entry))) {
- if (apt.error)
- cancel = true;
- apt.error = 0;
- mask = 0;
- }
- if (mask || apt.error) {
- list_del_init(&req->wait.entry);
- } else if (cancel) {
- WRITE_ONCE(req->cancelled, true);
- } else if (!req->done) { /* actually waiting for an event */
- list_add_tail(&aiocb->ki_list, &ctx->active_reqs);
- aiocb->ki_cancel = aio_poll_cancel;
- }
- spin_unlock(&req->head->lock);
+ if (unlikely(!req->head))
+ goto out;
+ spin_lock(&req->head->lock);
+ if (unlikely(list_empty(&req->wait.entry))) {
+ if (apt.error)
+ cancel = true;
+ apt.error = 0;
+ mask = 0;
}
+ if (mask || apt.error) {
+ list_del_init(&req->wait.entry);
+ } else if (cancel) {
+ WRITE_ONCE(req->cancelled, true);
+ } else if (!req->done) { /* actually waiting for an event */
+ list_add_tail(&aiocb->ki_list, &ctx->active_reqs);
+ aiocb->ki_cancel = aio_poll_cancel;
+ }
+ spin_unlock(&req->head->lock);
+out:
if (mask) { /* no async, we'd stolen it */
aiocb->ki_res.res = mangle_poll(mask);
apt.error = 0;
@@ -2045,20 +2065,21 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
}

static long do_io_getevents(aio_context_t ctx_id,
- long min_nr,
- long nr,
- struct io_event __user *events,
- struct timespec64 *ts)
+ long min_nr,
+ long nr,
+ struct io_event __user *events,
+ struct timespec64 *ts)
{
ktime_t until = ts ? timespec64_to_ktime(*ts) : KTIME_MAX;
struct kioctx *ioctx = lookup_ioctx(ctx_id);
long ret = -EINVAL;

- if (likely(ioctx)) {
- if (likely(min_nr <= nr && min_nr >= 0))
- ret = read_events(ioctx, min_nr, nr, events, until);
- percpu_ref_put(&ioctx->users);
- }
+ if (unlikely(!ioctx))
+ return -EINVAL;
+
+ if (likely(min_nr <= nr && min_nr >= 0))
+ ret = read_events(ioctx, min_nr, nr, events, until);
+ percpu_ref_put(&ioctx->users);

return ret;
}
@@ -2156,7 +2177,6 @@ SYSCALL_DEFINE6(io_pgetevents_time32,
if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
return -EFAULT;

-
ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);
if (ret)
return ret;
@@ -2205,12 +2225,12 @@ struct __compat_aio_sigset {
#if defined(CONFIG_COMPAT_32BIT_TIME)

COMPAT_SYSCALL_DEFINE6(io_pgetevents,
- compat_aio_context_t, ctx_id,
- compat_long_t, min_nr,
- compat_long_t, nr,
- struct io_event __user *, events,
- struct old_timespec32 __user *, timeout,
- const struct __compat_aio_sigset __user *, usig)
+ compat_aio_context_t, ctx_id,
+ compat_long_t, min_nr,
+ compat_long_t, nr,
+ struct io_event __user *, events,
+ struct old_timespec32 __user *, timeout,
+ const struct __compat_aio_sigset __user *, usig)
{
struct __compat_aio_sigset ksig = { 0, };
struct timespec64 t;
@@ -2240,12 +2260,12 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents,
#endif

COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64,
- compat_aio_context_t, ctx_id,
- compat_long_t, min_nr,
- compat_long_t, nr,
- struct io_event __user *, events,
- struct __kernel_timespec __user *, timeout,
- const struct __compat_aio_sigset __user *, usig)
+ compat_aio_context_t, ctx_id,
+ compat_long_t, min_nr,
+ compat_long_t, nr,
+ struct io_event __user *, events,
+ struct __kernel_timespec __user *, timeout,
+ const struct __compat_aio_sigset __user *, usig)
{
struct __compat_aio_sigset ksig = { 0, };
struct timespec64 t;
--
2.28.0