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io_uring: pick up link work on submit reference drop
[tomoyo/tomoyo-test1.git] / fs / io_uring.c
index 187dd94..f79ca49 100644 (file)
@@ -46,6 +46,7 @@
 #include <linux/compat.h>
 #include <linux/refcount.h>
 #include <linux/uio.h>
+#include <linux/bits.h>
 
 #include <linux/sched/signal.h>
 #include <linux/fs.h>
 #include <linux/sizes.h>
 #include <linux/hugetlb.h>
 #include <linux/highmem.h>
+#include <linux/namei.h>
+#include <linux/fsnotify.h>
+#include <linux/fadvise.h>
+#include <linux/eventpoll.h>
+#include <linux/fs_struct.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/io_uring.h>
@@ -177,6 +183,21 @@ struct fixed_file_table {
        struct file             **files;
 };
 
+enum {
+       FFD_F_ATOMIC,
+};
+
+struct fixed_file_data {
+       struct fixed_file_table         *table;
+       struct io_ring_ctx              *ctx;
+
+       struct percpu_ref               refs;
+       struct llist_head               put_llist;
+       unsigned long                   state;
+       struct work_struct              ref_work;
+       struct completion               done;
+};
+
 struct io_ring_ctx {
        struct {
                struct percpu_ref       refs;
@@ -184,10 +205,11 @@ struct io_ring_ctx {
 
        struct {
                unsigned int            flags;
-               bool                    compat;
-               bool                    account_mem;
-               bool                    cq_overflow_flushed;
-               bool                    drain_next;
+               unsigned int            compat: 1;
+               unsigned int            account_mem: 1;
+               unsigned int            cq_overflow_flushed: 1;
+               unsigned int            drain_next: 1;
+               unsigned int            eventfd_async: 1;
 
                /*
                 * Ring buffer of indices into array of io_uring_sqe, which is
@@ -207,13 +229,14 @@ struct io_ring_ctx {
                unsigned                sq_thread_idle;
                unsigned                cached_sq_dropped;
                atomic_t                cached_cq_overflow;
-               struct io_uring_sqe     *sq_sqes;
+               unsigned long           sq_check_overflow;
 
                struct list_head        defer_list;
                struct list_head        timeout_list;
                struct list_head        cq_overflow_list;
 
                wait_queue_head_t       inflight_wait;
+               struct io_uring_sqe     *sq_sqes;
        } ____cacheline_aligned_in_smp;
 
        struct io_rings *rings;
@@ -229,8 +252,10 @@ struct io_ring_ctx {
         * readers must ensure that ->refs is alive as long as the file* is
         * used. Only updated through io_uring_register(2).
         */
-       struct fixed_file_table *file_table;
+       struct fixed_file_data  *file_data;
        unsigned                nr_user_files;
+       int                     ring_fd;
+       struct file             *ring_file;
 
        /* if used, fixed mapped user buffers */
        unsigned                nr_user_bufs;
@@ -250,11 +275,14 @@ struct io_ring_ctx {
        struct socket           *ring_sock;
 #endif
 
+       struct idr              personality_idr;
+
        struct {
                unsigned                cached_cq_tail;
                unsigned                cq_entries;
                unsigned                cq_mask;
                atomic_t                cq_timeouts;
+               unsigned long           cq_check_overflow;
                struct wait_queue_head  cq_wait;
                struct fasync_struct    *cq_fasync;
                struct eventfd_ctx      *cq_ev_fd;
@@ -267,7 +295,8 @@ struct io_ring_ctx {
 
        struct {
                spinlock_t              completion_lock;
-               bool                    poll_multi_file;
+               struct llist_head       poll_llist;
+
                /*
                 * ->poll_list is protected by the ctx->uring_lock for
                 * io_uring instances that don't use IORING_SETUP_SQPOLL.
@@ -277,6 +306,7 @@ struct io_ring_ctx {
                struct list_head        poll_list;
                struct hlist_head       *cancel_hash;
                unsigned                cancel_hash_bits;
+               bool                    poll_multi_file;
 
                spinlock_t              inflight_lock;
                struct list_head        inflight_list;
@@ -299,6 +329,12 @@ struct io_poll_iocb {
        struct wait_queue_entry         wait;
 };
 
+struct io_close {
+       struct file                     *file;
+       struct file                     *put_file;
+       int                             fd;
+};
+
 struct io_timeout_data {
        struct io_kiocb                 *req;
        struct hrtimer                  timer;
@@ -319,6 +355,7 @@ struct io_sync {
        loff_t                          len;
        loff_t                          off;
        int                             flags;
+       int                             mode;
 };
 
 struct io_cancel {
@@ -348,8 +385,52 @@ struct io_connect {
 
 struct io_sr_msg {
        struct file                     *file;
-       struct user_msghdr __user       *msg;
+       union {
+               struct user_msghdr __user *msg;
+               void __user             *buf;
+       };
        int                             msg_flags;
+       size_t                          len;
+};
+
+struct io_open {
+       struct file                     *file;
+       int                             dfd;
+       union {
+               unsigned                mask;
+       };
+       struct filename                 *filename;
+       struct statx __user             *buffer;
+       struct open_how                 how;
+};
+
+struct io_files_update {
+       struct file                     *file;
+       u64                             arg;
+       u32                             nr_args;
+       u32                             offset;
+};
+
+struct io_fadvise {
+       struct file                     *file;
+       u64                             offset;
+       u32                             len;
+       u32                             advice;
+};
+
+struct io_madvise {
+       struct file                     *file;
+       u64                             addr;
+       u32                             len;
+       u32                             advice;
+};
+
+struct io_epoll {
+       struct file                     *file;
+       int                             epfd;
+       int                             op;
+       int                             fd;
+       struct epoll_event              event;
 };
 
 struct io_async_connect {
@@ -361,6 +442,7 @@ struct io_async_msghdr {
        struct iovec                    *iov;
        struct sockaddr __user          *uaddr;
        struct msghdr                   msg;
+       struct sockaddr_storage         addr;
 };
 
 struct io_async_rw {
@@ -379,6 +461,71 @@ struct io_async_ctx {
        };
 };
 
+enum {
+       REQ_F_FIXED_FILE_BIT    = IOSQE_FIXED_FILE_BIT,
+       REQ_F_IO_DRAIN_BIT      = IOSQE_IO_DRAIN_BIT,
+       REQ_F_LINK_BIT          = IOSQE_IO_LINK_BIT,
+       REQ_F_HARDLINK_BIT      = IOSQE_IO_HARDLINK_BIT,
+       REQ_F_FORCE_ASYNC_BIT   = IOSQE_ASYNC_BIT,
+
+       REQ_F_LINK_NEXT_BIT,
+       REQ_F_FAIL_LINK_BIT,
+       REQ_F_INFLIGHT_BIT,
+       REQ_F_CUR_POS_BIT,
+       REQ_F_NOWAIT_BIT,
+       REQ_F_IOPOLL_COMPLETED_BIT,
+       REQ_F_LINK_TIMEOUT_BIT,
+       REQ_F_TIMEOUT_BIT,
+       REQ_F_ISREG_BIT,
+       REQ_F_MUST_PUNT_BIT,
+       REQ_F_TIMEOUT_NOSEQ_BIT,
+       REQ_F_COMP_LOCKED_BIT,
+       REQ_F_NEED_CLEANUP_BIT,
+       REQ_F_OVERFLOW_BIT,
+};
+
+enum {
+       /* ctx owns file */
+       REQ_F_FIXED_FILE        = BIT(REQ_F_FIXED_FILE_BIT),
+       /* drain existing IO first */
+       REQ_F_IO_DRAIN          = BIT(REQ_F_IO_DRAIN_BIT),
+       /* linked sqes */
+       REQ_F_LINK              = BIT(REQ_F_LINK_BIT),
+       /* doesn't sever on completion < 0 */
+       REQ_F_HARDLINK          = BIT(REQ_F_HARDLINK_BIT),
+       /* IOSQE_ASYNC */
+       REQ_F_FORCE_ASYNC       = BIT(REQ_F_FORCE_ASYNC_BIT),
+
+       /* already grabbed next link */
+       REQ_F_LINK_NEXT         = BIT(REQ_F_LINK_NEXT_BIT),
+       /* fail rest of links */
+       REQ_F_FAIL_LINK         = BIT(REQ_F_FAIL_LINK_BIT),
+       /* on inflight list */
+       REQ_F_INFLIGHT          = BIT(REQ_F_INFLIGHT_BIT),
+       /* read/write uses file position */
+       REQ_F_CUR_POS           = BIT(REQ_F_CUR_POS_BIT),
+       /* must not punt to workers */
+       REQ_F_NOWAIT            = BIT(REQ_F_NOWAIT_BIT),
+       /* polled IO has completed */
+       REQ_F_IOPOLL_COMPLETED  = BIT(REQ_F_IOPOLL_COMPLETED_BIT),
+       /* has linked timeout */
+       REQ_F_LINK_TIMEOUT      = BIT(REQ_F_LINK_TIMEOUT_BIT),
+       /* timeout request */
+       REQ_F_TIMEOUT           = BIT(REQ_F_TIMEOUT_BIT),
+       /* regular file */
+       REQ_F_ISREG             = BIT(REQ_F_ISREG_BIT),
+       /* must be punted even for NONBLOCK */
+       REQ_F_MUST_PUNT         = BIT(REQ_F_MUST_PUNT_BIT),
+       /* no timeout sequence */
+       REQ_F_TIMEOUT_NOSEQ     = BIT(REQ_F_TIMEOUT_NOSEQ_BIT),
+       /* completion under lock */
+       REQ_F_COMP_LOCKED       = BIT(REQ_F_COMP_LOCKED_BIT),
+       /* needs cleanup */
+       REQ_F_NEED_CLEANUP      = BIT(REQ_F_NEED_CLEANUP_BIT),
+       /* in overflow list */
+       REQ_F_OVERFLOW          = BIT(REQ_F_OVERFLOW_BIT),
+};
+
 /*
  * NOTE! Each of the iocb union members has the file pointer
  * as the first entry in their struct definition. So you can
@@ -396,12 +543,19 @@ struct io_kiocb {
                struct io_timeout       timeout;
                struct io_connect       connect;
                struct io_sr_msg        sr_msg;
+               struct io_open          open;
+               struct io_close         close;
+               struct io_files_update  files_update;
+               struct io_fadvise       fadvise;
+               struct io_madvise       madvise;
+               struct io_epoll         epoll;
        };
 
        struct io_async_ctx             *io;
-       struct file                     *ring_file;
-       int                             ring_fd;
-       bool                            has_user;
+       /*
+        * llist_node is only used for poll deferred completions
+        */
+       struct llist_node               llist_node;
        bool                            in_async;
        bool                            needs_fixed_file;
        u8                              opcode;
@@ -414,23 +568,6 @@ struct io_kiocb {
        struct list_head        link_list;
        unsigned int            flags;
        refcount_t              refs;
-#define REQ_F_NOWAIT           1       /* must not punt to workers */
-#define REQ_F_IOPOLL_COMPLETED 2       /* polled IO has completed */
-#define REQ_F_FIXED_FILE       4       /* ctx owns file */
-#define REQ_F_LINK_NEXT                8       /* already grabbed next link */
-#define REQ_F_IO_DRAIN         16      /* drain existing IO first */
-#define REQ_F_IO_DRAINED       32      /* drain done */
-#define REQ_F_LINK             64      /* linked sqes */
-#define REQ_F_LINK_TIMEOUT     128     /* has linked timeout */
-#define REQ_F_FAIL_LINK                256     /* fail rest of links */
-#define REQ_F_DRAIN_LINK       512     /* link should be fully drained */
-#define REQ_F_TIMEOUT          1024    /* timeout request */
-#define REQ_F_ISREG            2048    /* regular file */
-#define REQ_F_MUST_PUNT                4096    /* must be punted even for NONBLOCK */
-#define REQ_F_TIMEOUT_NOSEQ    8192    /* no timeout sequence */
-#define REQ_F_INFLIGHT         16384   /* on inflight list */
-#define REQ_F_COMP_LOCKED      32768   /* completion under lock */
-#define REQ_F_HARDLINK         65536   /* doesn't sever on completion < 0 */
        u64                     user_data;
        u32                     result;
        u32                     sequence;
@@ -450,8 +587,7 @@ struct io_submit_state {
         * io_kiocb alloc cache
         */
        void                    *reqs[IO_IOPOLL_BATCH];
-       unsigned                int free_reqs;
-       unsigned                int cur_req;
+       unsigned int            free_reqs;
 
        /*
         * File reference cache
@@ -463,14 +599,171 @@ struct io_submit_state {
        unsigned int            ios_left;
 };
 
+struct io_op_def {
+       /* needs req->io allocated for deferral/async */
+       unsigned                async_ctx : 1;
+       /* needs current->mm setup, does mm access */
+       unsigned                needs_mm : 1;
+       /* needs req->file assigned */
+       unsigned                needs_file : 1;
+       /* needs req->file assigned IFF fd is >= 0 */
+       unsigned                fd_non_neg : 1;
+       /* hash wq insertion if file is a regular file */
+       unsigned                hash_reg_file : 1;
+       /* unbound wq insertion if file is a non-regular file */
+       unsigned                unbound_nonreg_file : 1;
+       /* opcode is not supported by this kernel */
+       unsigned                not_supported : 1;
+       /* needs file table */
+       unsigned                file_table : 1;
+       /* needs ->fs */
+       unsigned                needs_fs : 1;
+};
+
+static const struct io_op_def io_op_defs[] = {
+       [IORING_OP_NOP] = {},
+       [IORING_OP_READV] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_WRITEV] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .hash_reg_file          = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_FSYNC] = {
+               .needs_file             = 1,
+       },
+       [IORING_OP_READ_FIXED] = {
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_WRITE_FIXED] = {
+               .needs_file             = 1,
+               .hash_reg_file          = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_POLL_ADD] = {
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_POLL_REMOVE] = {},
+       [IORING_OP_SYNC_FILE_RANGE] = {
+               .needs_file             = 1,
+       },
+       [IORING_OP_SENDMSG] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+               .needs_fs               = 1,
+       },
+       [IORING_OP_RECVMSG] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+               .needs_fs               = 1,
+       },
+       [IORING_OP_TIMEOUT] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+       },
+       [IORING_OP_TIMEOUT_REMOVE] = {},
+       [IORING_OP_ACCEPT] = {
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+               .file_table             = 1,
+       },
+       [IORING_OP_ASYNC_CANCEL] = {},
+       [IORING_OP_LINK_TIMEOUT] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+       },
+       [IORING_OP_CONNECT] = {
+               .async_ctx              = 1,
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_FALLOCATE] = {
+               .needs_file             = 1,
+       },
+       [IORING_OP_OPENAT] = {
+               .needs_file             = 1,
+               .fd_non_neg             = 1,
+               .file_table             = 1,
+               .needs_fs               = 1,
+       },
+       [IORING_OP_CLOSE] = {
+               .needs_file             = 1,
+               .file_table             = 1,
+       },
+       [IORING_OP_FILES_UPDATE] = {
+               .needs_mm               = 1,
+               .file_table             = 1,
+       },
+       [IORING_OP_STATX] = {
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .fd_non_neg             = 1,
+               .needs_fs               = 1,
+       },
+       [IORING_OP_READ] = {
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_WRITE] = {
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_FADVISE] = {
+               .needs_file             = 1,
+       },
+       [IORING_OP_MADVISE] = {
+               .needs_mm               = 1,
+       },
+       [IORING_OP_SEND] = {
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_RECV] = {
+               .needs_mm               = 1,
+               .needs_file             = 1,
+               .unbound_nonreg_file    = 1,
+       },
+       [IORING_OP_OPENAT2] = {
+               .needs_file             = 1,
+               .fd_non_neg             = 1,
+               .file_table             = 1,
+               .needs_fs               = 1,
+       },
+       [IORING_OP_EPOLL_CTL] = {
+               .unbound_nonreg_file    = 1,
+               .file_table             = 1,
+       },
+};
+
 static void io_wq_submit_work(struct io_wq_work **workptr);
 static void io_cqring_fill_event(struct io_kiocb *req, long res);
-static void __io_free_req(struct io_kiocb *req);
 static void io_put_req(struct io_kiocb *req);
-static void io_double_put_req(struct io_kiocb *req);
 static void __io_double_put_req(struct io_kiocb *req);
 static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
 static void io_queue_linked_timeout(struct io_kiocb *req);
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+                                struct io_uring_files_update *ip,
+                                unsigned nr_args);
+static int io_grab_files(struct io_kiocb *req);
+static void io_ring_file_ref_flush(struct fixed_file_data *data);
+static void io_cleanup_req(struct io_kiocb *req);
 
 static struct kmem_cache *req_cachep;
 
@@ -537,9 +830,11 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
        INIT_LIST_HEAD(&ctx->cq_overflow_list);
        init_completion(&ctx->completions[0]);
        init_completion(&ctx->completions[1]);
+       idr_init(&ctx->personality_idr);
        mutex_init(&ctx->uring_lock);
        init_waitqueue_head(&ctx->wait);
        spin_lock_init(&ctx->completion_lock);
+       init_llist_head(&ctx->poll_llist);
        INIT_LIST_HEAD(&ctx->poll_list);
        INIT_LIST_HEAD(&ctx->defer_list);
        INIT_LIST_HEAD(&ctx->timeout_list);
@@ -566,7 +861,7 @@ static inline bool __req_need_defer(struct io_kiocb *req)
 
 static inline bool req_need_defer(struct io_kiocb *req)
 {
-       if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) == REQ_F_IO_DRAIN)
+       if (unlikely(req->flags & REQ_F_IO_DRAIN))
                return __req_need_defer(req);
 
        return false;
@@ -606,53 +901,75 @@ static void __io_commit_cqring(struct io_ring_ctx *ctx)
 {
        struct io_rings *rings = ctx->rings;
 
-       if (ctx->cached_cq_tail != READ_ONCE(rings->cq.tail)) {
-               /* order cqe stores with ring update */
-               smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
+       /* order cqe stores with ring update */
+       smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
 
-               if (wq_has_sleeper(&ctx->cq_wait)) {
-                       wake_up_interruptible(&ctx->cq_wait);
-                       kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
+       if (wq_has_sleeper(&ctx->cq_wait)) {
+               wake_up_interruptible(&ctx->cq_wait);
+               kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
+       }
+}
+
+static inline void io_req_work_grab_env(struct io_kiocb *req,
+                                       const struct io_op_def *def)
+{
+       if (!req->work.mm && def->needs_mm) {
+               mmgrab(current->mm);
+               req->work.mm = current->mm;
+       }
+       if (!req->work.creds)
+               req->work.creds = get_current_cred();
+       if (!req->work.fs && def->needs_fs) {
+               spin_lock(&current->fs->lock);
+               if (!current->fs->in_exec) {
+                       req->work.fs = current->fs;
+                       req->work.fs->users++;
+               } else {
+                       req->work.flags |= IO_WQ_WORK_CANCEL;
                }
+               spin_unlock(&current->fs->lock);
        }
+       if (!req->work.task_pid)
+               req->work.task_pid = task_pid_vnr(current);
 }
 
-static inline bool io_req_needs_user(struct io_kiocb *req)
+static inline void io_req_work_drop_env(struct io_kiocb *req)
 {
-       return !(req->opcode == IORING_OP_READ_FIXED ||
-                req->opcode == IORING_OP_WRITE_FIXED);
+       if (req->work.mm) {
+               mmdrop(req->work.mm);
+               req->work.mm = NULL;
+       }
+       if (req->work.creds) {
+               put_cred(req->work.creds);
+               req->work.creds = NULL;
+       }
+       if (req->work.fs) {
+               struct fs_struct *fs = req->work.fs;
+
+               spin_lock(&req->work.fs->lock);
+               if (--fs->users)
+                       fs = NULL;
+               spin_unlock(&req->work.fs->lock);
+               if (fs)
+                       free_fs_struct(fs);
+       }
 }
 
 static inline bool io_prep_async_work(struct io_kiocb *req,
                                      struct io_kiocb **link)
 {
+       const struct io_op_def *def = &io_op_defs[req->opcode];
        bool do_hashed = false;
 
-       switch (req->opcode) {
-       case IORING_OP_WRITEV:
-       case IORING_OP_WRITE_FIXED:
-               /* only regular files should be hashed for writes */
-               if (req->flags & REQ_F_ISREG)
+       if (req->flags & REQ_F_ISREG) {
+               if (def->hash_reg_file)
                        do_hashed = true;
-               /* fall-through */
-       case IORING_OP_READV:
-       case IORING_OP_READ_FIXED:
-       case IORING_OP_SENDMSG:
-       case IORING_OP_RECVMSG:
-       case IORING_OP_ACCEPT:
-       case IORING_OP_POLL_ADD:
-       case IORING_OP_CONNECT:
-               /*
-                * We know REQ_F_ISREG is not set on some of these
-                * opcodes, but this enables us to keep the check in
-                * just one place.
-                */
-               if (!(req->flags & REQ_F_ISREG))
+       } else {
+               if (def->unbound_nonreg_file)
                        req->work.flags |= IO_WQ_WORK_UNBOUND;
-               break;
        }
-       if (io_req_needs_user(req))
-               req->work.flags |= IO_WQ_WORK_NEEDS_USER;
+
+       io_req_work_grab_env(req, def);
 
        *link = io_prep_linked_timeout(req);
        return do_hashed;
@@ -711,10 +1028,8 @@ static void io_commit_cqring(struct io_ring_ctx *ctx)
 
        __io_commit_cqring(ctx);
 
-       while ((req = io_get_deferred_req(ctx)) != NULL) {
-               req->flags |= REQ_F_IO_DRAINED;
+       while ((req = io_get_deferred_req(ctx)) != NULL)
                io_queue_async_work(req);
-       }
 }
 
 static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
@@ -735,16 +1050,30 @@ static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
        return &rings->cqes[tail & ctx->cq_mask];
 }
 
-static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
+static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
+{
+       if (!ctx->cq_ev_fd)
+               return false;
+       if (!ctx->eventfd_async)
+               return true;
+       return io_wq_current_is_worker() || in_interrupt();
+}
+
+static void __io_cqring_ev_posted(struct io_ring_ctx *ctx, bool trigger_ev)
 {
        if (waitqueue_active(&ctx->wait))
                wake_up(&ctx->wait);
        if (waitqueue_active(&ctx->sqo_wait))
                wake_up(&ctx->sqo_wait);
-       if (ctx->cq_ev_fd)
+       if (trigger_ev)
                eventfd_signal(ctx->cq_ev_fd, 1);
 }
 
+static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
+{
+       __io_cqring_ev_posted(ctx, io_should_trigger_evfd(ctx));
+}
+
 /* Returns true if there are no backlogged entries after the flush */
 static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
 {
@@ -766,7 +1095,7 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
 
        /* if force is set, the ring is going away. always drop after that */
        if (force)
-               ctx->cq_overflow_flushed = true;
+               ctx->cq_overflow_flushed = 1;
 
        cqe = NULL;
        while (!list_empty(&ctx->cq_overflow_list)) {
@@ -777,6 +1106,7 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
                req = list_first_entry(&ctx->cq_overflow_list, struct io_kiocb,
                                                list);
                list_move(&req->list, &list);
+               req->flags &= ~REQ_F_OVERFLOW;
                if (cqe) {
                        WRITE_ONCE(cqe->user_data, req->user_data);
                        WRITE_ONCE(cqe->res, req->result);
@@ -788,6 +1118,10 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
        }
 
        io_commit_cqring(ctx);
+       if (cqe) {
+               clear_bit(0, &ctx->sq_check_overflow);
+               clear_bit(0, &ctx->cq_check_overflow);
+       }
        spin_unlock_irqrestore(&ctx->completion_lock, flags);
        io_cqring_ev_posted(ctx);
 
@@ -821,6 +1155,11 @@ static void io_cqring_fill_event(struct io_kiocb *req, long res)
                WRITE_ONCE(ctx->rings->cq_overflow,
                                atomic_inc_return(&ctx->cached_cq_overflow));
        } else {
+               if (list_empty(&ctx->cq_overflow_list)) {
+                       set_bit(0, &ctx->sq_check_overflow);
+                       set_bit(0, &ctx->cq_check_overflow);
+               }
+               req->flags |= REQ_F_OVERFLOW;
                refcount_inc(&req->refs);
                req->result = res;
                list_add_tail(&req->list, &ctx->cq_overflow_list);
@@ -863,9 +1202,6 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
        gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
        struct io_kiocb *req;
 
-       if (!percpu_ref_tryget(&ctx->refs))
-               return NULL;
-
        if (!state) {
                req = kmem_cache_alloc(req_cachep, gfp);
                if (unlikely(!req))
@@ -888,17 +1224,14 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
                        ret = 1;
                }
                state->free_reqs = ret - 1;
-               state->cur_req = 1;
-               req = state->reqs[0];
+               req = state->reqs[ret - 1];
        } else {
-               req = state->reqs[state->cur_req];
                state->free_reqs--;
-               state->cur_req++;
+               req = state->reqs[state->free_reqs];
        }
 
 got_it:
        req->io = NULL;
-       req->ring_file = NULL;
        req->file = NULL;
        req->ctx = ctx;
        req->flags = 0;
@@ -915,24 +1248,38 @@ fallback:
        return NULL;
 }
 
-static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr)
+static void __io_req_do_free(struct io_kiocb *req)
+{
+       if (likely(!io_is_fallback_req(req)))
+               kmem_cache_free(req_cachep, req);
+       else
+               clear_bit_unlock(0, (unsigned long *) req->ctx->fallback_req);
+}
+
+static void __io_req_aux_free(struct io_kiocb *req)
 {
-       if (*nr) {
-               kmem_cache_free_bulk(req_cachep, *nr, reqs);
-               percpu_ref_put_many(&ctx->refs, *nr);
-               *nr = 0;
+       struct io_ring_ctx *ctx = req->ctx;
+
+       if (req->flags & REQ_F_NEED_CLEANUP)
+               io_cleanup_req(req);
+
+       kfree(req->io);
+       if (req->file) {
+               if (req->flags & REQ_F_FIXED_FILE)
+                       percpu_ref_put(&ctx->file_data->refs);
+               else
+                       fput(req->file);
        }
+
+       io_req_work_drop_env(req);
 }
 
 static void __io_free_req(struct io_kiocb *req)
 {
-       struct io_ring_ctx *ctx = req->ctx;
+       __io_req_aux_free(req);
 
-       if (req->io)
-               kfree(req->io);
-       if (req->file && !(req->flags & REQ_F_FIXED_FILE))
-               fput(req->file);
        if (req->flags & REQ_F_INFLIGHT) {
+               struct io_ring_ctx *ctx = req->ctx;
                unsigned long flags;
 
                spin_lock_irqsave(&ctx->inflight_lock, flags);
@@ -941,11 +1288,63 @@ static void __io_free_req(struct io_kiocb *req)
                        wake_up(&ctx->inflight_wait);
                spin_unlock_irqrestore(&ctx->inflight_lock, flags);
        }
-       percpu_ref_put(&ctx->refs);
-       if (likely(!io_is_fallback_req(req)))
-               kmem_cache_free(req_cachep, req);
-       else
-               clear_bit_unlock(0, (unsigned long *) ctx->fallback_req);
+
+       percpu_ref_put(&req->ctx->refs);
+       __io_req_do_free(req);
+}
+
+struct req_batch {
+       void *reqs[IO_IOPOLL_BATCH];
+       int to_free;
+       int need_iter;
+};
+
+static void io_free_req_many(struct io_ring_ctx *ctx, struct req_batch *rb)
+{
+       int fixed_refs = rb->to_free;
+
+       if (!rb->to_free)
+               return;
+       if (rb->need_iter) {
+               int i, inflight = 0;
+               unsigned long flags;
+
+               fixed_refs = 0;
+               for (i = 0; i < rb->to_free; i++) {
+                       struct io_kiocb *req = rb->reqs[i];
+
+                       if (req->flags & REQ_F_FIXED_FILE) {
+                               req->file = NULL;
+                               fixed_refs++;
+                       }
+                       if (req->flags & REQ_F_INFLIGHT)
+                               inflight++;
+                       __io_req_aux_free(req);
+               }
+               if (!inflight)
+                       goto do_free;
+
+               spin_lock_irqsave(&ctx->inflight_lock, flags);
+               for (i = 0; i < rb->to_free; i++) {
+                       struct io_kiocb *req = rb->reqs[i];
+
+                       if (req->flags & REQ_F_INFLIGHT) {
+                               list_del(&req->inflight_entry);
+                               if (!--inflight)
+                                       break;
+                       }
+               }
+               spin_unlock_irqrestore(&ctx->inflight_lock, flags);
+
+               if (waitqueue_active(&ctx->inflight_wait))
+                       wake_up(&ctx->inflight_wait);
+       }
+do_free:
+       kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
+       if (fixed_refs)
+               percpu_ref_put_many(&ctx->file_data->refs, fixed_refs);
+       percpu_ref_put_many(&ctx->refs, rb->to_free);
+       rb->to_free = rb->need_iter = 0;
 }
 
 static bool io_link_cancel_timeout(struct io_kiocb *req)
@@ -1084,10 +1483,10 @@ static void io_free_req(struct io_kiocb *req)
 __attribute__((nonnull))
 static void io_put_req_find_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
 {
-       io_req_find_next(req, nxtptr);
-
-       if (refcount_dec_and_test(&req->refs))
+       if (refcount_dec_and_test(&req->refs)) {
+               io_req_find_next(req, nxtptr);
                __io_free_req(req);
+       }
 }
 
 static void io_put_req(struct io_kiocb *req)
@@ -1118,19 +1517,21 @@ static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush)
 {
        struct io_rings *rings = ctx->rings;
 
-       /*
-        * noflush == true is from the waitqueue handler, just ensure we wake
-        * up the task, and the next invocation will flush the entries. We
-        * cannot safely to it from here.
-        */
-       if (noflush && !list_empty(&ctx->cq_overflow_list))
-               return -1U;
+       if (test_bit(0, &ctx->cq_check_overflow)) {
+               /*
+                * noflush == true is from the waitqueue handler, just ensure
+                * we wake up the task, and the next invocation will flush the
+                * entries. We cannot safely to it from here.
+                */
+               if (noflush && !list_empty(&ctx->cq_overflow_list))
+                       return -1U;
 
-       io_cqring_overflow_flush(ctx, false);
+               io_cqring_overflow_flush(ctx, false);
+       }
 
        /* See comment at the top of this file */
        smp_rmb();
-       return READ_ONCE(rings->cq.tail) - READ_ONCE(rings->cq.head);
+       return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
 }
 
 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
@@ -1141,17 +1542,30 @@ static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
        return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
 }
 
+static inline bool io_req_multi_free(struct req_batch *rb, struct io_kiocb *req)
+{
+       if ((req->flags & REQ_F_LINK) || io_is_fallback_req(req))
+               return false;
+
+       if (!(req->flags & REQ_F_FIXED_FILE) || req->io)
+               rb->need_iter++;
+
+       rb->reqs[rb->to_free++] = req;
+       if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
+               io_free_req_many(req->ctx, rb);
+       return true;
+}
+
 /*
  * Find and free completed poll iocbs
  */
 static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
                               struct list_head *done)
 {
-       void *reqs[IO_IOPOLL_BATCH];
+       struct req_batch rb;
        struct io_kiocb *req;
-       int to_free;
 
-       to_free = 0;
+       rb.to_free = rb.need_iter = 0;
        while (!list_empty(done)) {
                req = list_first_entry(done, struct io_kiocb, list);
                list_del(&req->list);
@@ -1159,26 +1573,13 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
                io_cqring_fill_event(req, req->result);
                (*nr_events)++;
 
-               if (refcount_dec_and_test(&req->refs)) {
-                       /* If we're not using fixed files, we have to pair the
-                        * completion part with the file put. Use regular
-                        * completions for those, only batch free for fixed
-                        * file and non-linked commands.
-                        */
-                       if (((req->flags & (REQ_F_FIXED_FILE|REQ_F_LINK)) ==
-                           REQ_F_FIXED_FILE) && !io_is_fallback_req(req) &&
-                           !req->io) {
-                               reqs[to_free++] = req;
-                               if (to_free == ARRAY_SIZE(reqs))
-                                       io_free_req_many(ctx, reqs, &to_free);
-                       } else {
-                               io_free_req(req);
-                       }
-               }
+               if (refcount_dec_and_test(&req->refs) &&
+                   !io_req_multi_free(&rb, req))
+                       io_free_req(req);
        }
 
        io_commit_cqring(ctx);
-       io_free_req_many(ctx, reqs, &to_free);
+       io_free_req_many(ctx, &rb);
 }
 
 static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
@@ -1271,11 +1672,17 @@ static void io_iopoll_reap_events(struct io_ring_ctx *ctx)
        mutex_unlock(&ctx->uring_lock);
 }
 
-static int __io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
-                           long min)
+static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
+                          long min)
 {
        int iters = 0, ret = 0;
 
+       /*
+        * We disallow the app entering submit/complete with polling, but we
+        * still need to lock the ring to prevent racing with polled issue
+        * that got punted to a workqueue.
+        */
+       mutex_lock(&ctx->uring_lock);
        do {
                int tmin = 0;
 
@@ -1311,21 +1718,6 @@ static int __io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
                ret = 0;
        } while (min && !*nr_events && !need_resched());
 
-       return ret;
-}
-
-static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
-                          long min)
-{
-       int ret;
-
-       /*
-        * We disallow the app entering submit/complete with polling, but we
-        * still need to lock the ring to prevent racing with polled issue
-        * that got punted to a workqueue.
-        */
-       mutex_lock(&ctx->uring_lock);
-       ret = __io_iopoll_check(ctx, nr_events, min);
        mutex_unlock(&ctx->uring_lock);
        return ret;
 }
@@ -1429,6 +1821,10 @@ static void io_iopoll_req_issued(struct io_kiocb *req)
                list_add(&req->list, &ctx->poll_list);
        else
                list_add_tail(&req->list, &ctx->poll_list);
+
+       if ((ctx->flags & IORING_SETUP_SQPOLL) &&
+           wq_has_sleeper(&ctx->sqo_wait))
+               wake_up(&ctx->sqo_wait);
 }
 
 static void io_file_put(struct io_submit_state *state)
@@ -1496,15 +1892,19 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
        unsigned ioprio;
        int ret;
 
-       if (!req->file)
-               return -EBADF;
-
        if (S_ISREG(file_inode(req->file)->i_mode))
                req->flags |= REQ_F_ISREG;
 
        kiocb->ki_pos = READ_ONCE(sqe->off);
-       kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
+       if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
+               req->flags |= REQ_F_CUR_POS;
+               kiocb->ki_pos = req->file->f_pos;
+       }
        kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
+       kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
+       ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
+       if (unlikely(ret))
+               return ret;
 
        ioprio = READ_ONCE(sqe->ioprio);
        if (ioprio) {
@@ -1516,10 +1916,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
        } else
                kiocb->ki_ioprio = get_current_ioprio();
 
-       ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
-       if (unlikely(ret))
-               return ret;
-
        /* don't allow async punt if RWF_NOWAIT was requested */
        if ((kiocb->ki_flags & IOCB_NOWAIT) ||
            (req->file->f_flags & O_NONBLOCK))
@@ -1574,6 +1970,10 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
 static void kiocb_done(struct kiocb *kiocb, ssize_t ret, struct io_kiocb **nxt,
                       bool in_async)
 {
+       struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+       if (req->flags & REQ_F_CUR_POS)
+               req->file->f_pos = kiocb->ki_pos;
        if (in_async && ret >= 0 && kiocb->ki_complete == io_complete_rw)
                *nxt = __io_complete_rw(kiocb, ret);
        else
@@ -1671,6 +2071,13 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
        if (req->rw.kiocb.private)
                return -EINVAL;
 
+       if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
+               ssize_t ret;
+               ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
+               *iovec = NULL;
+               return ret;
+       }
+
        if (req->io) {
                struct io_async_rw *iorw = &req->io->rw;
 
@@ -1681,9 +2088,6 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
                return iorw->size;
        }
 
-       if (!req->has_user)
-               return -EFAULT;
-
 #ifdef CONFIG_COMPAT
        if (req->ctx->compat)
                return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
@@ -1762,38 +2166,31 @@ static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size,
                req->io->rw.iov = req->io->rw.fast_iov;
                memcpy(req->io->rw.iov, fast_iov,
                        sizeof(struct iovec) * iter->nr_segs);
+       } else {
+               req->flags |= REQ_F_NEED_CLEANUP;
        }
 }
 
 static int io_alloc_async_ctx(struct io_kiocb *req)
 {
+       if (!io_op_defs[req->opcode].async_ctx)
+               return 0;
        req->io = kmalloc(sizeof(*req->io), GFP_KERNEL);
        return req->io == NULL;
 }
 
-static void io_rw_async(struct io_wq_work **workptr)
-{
-       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
-       struct iovec *iov = NULL;
-
-       if (req->io->rw.iov != req->io->rw.fast_iov)
-               iov = req->io->rw.iov;
-       io_wq_submit_work(workptr);
-       kfree(iov);
-}
-
 static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size,
                             struct iovec *iovec, struct iovec *fast_iov,
                             struct iov_iter *iter)
 {
-       if (req->opcode == IORING_OP_READ_FIXED ||
-           req->opcode == IORING_OP_WRITE_FIXED)
+       if (!io_op_defs[req->opcode].async_ctx)
                return 0;
-       if (!req->io && io_alloc_async_ctx(req))
-               return -ENOMEM;
+       if (!req->io) {
+               if (io_alloc_async_ctx(req))
+                       return -ENOMEM;
 
-       io_req_map_rw(req, io_size, iovec, fast_iov, iter);
-       req->work.func = io_rw_async;
+               io_req_map_rw(req, io_size, iovec, fast_iov, iter);
+       }
        return 0;
 }
 
@@ -1811,7 +2208,8 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
        if (unlikely(!(req->file->f_mode & FMODE_READ)))
                return -EBADF;
 
-       if (!req->io)
+       /* either don't need iovec imported or already have it */
+       if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
                return 0;
 
        io = req->io;
@@ -1880,8 +2278,8 @@ copy_iov:
                }
        }
 out_free:
-       if (!io_wq_current_is_worker())
-               kfree(iovec);
+       kfree(iovec);
+       req->flags &= ~REQ_F_NEED_CLEANUP;
        return ret;
 }
 
@@ -1899,7 +2297,8 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
        if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
                return -EBADF;
 
-       if (!req->io)
+       /* either don't need iovec imported or already have it */
+       if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
                return 0;
 
        io = req->io;
@@ -1974,6 +2373,12 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
                        ret2 = call_write_iter(req->file, kiocb, &iter);
                else
                        ret2 = loop_rw_iter(WRITE, req->file, kiocb, &iter);
+               /*
+                * Raw bdev writes will -EOPNOTSUPP for IOCB_NOWAIT. Just
+                * retry them without IOCB_NOWAIT.
+                */
+               if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
+                       ret2 = -EAGAIN;
                if (!force_nonblock || ret2 != -EAGAIN) {
                        kiocb_done(kiocb, ret2, nxt, req->in_async);
                } else {
@@ -1986,8 +2391,8 @@ copy_iov:
                }
        }
 out_free:
-       if (!io_wq_current_is_worker())
-               kfree(iovec);
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       kfree(iovec);
        return ret;
 }
 
@@ -2101,25 +2506,7 @@ static int io_fsync(struct io_kiocb *req, struct io_kiocb **nxt,
        return 0;
 }
 
-static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
-       struct io_ring_ctx *ctx = req->ctx;
-
-       if (!req->file)
-               return -EBADF;
-
-       if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-               return -EINVAL;
-       if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
-               return -EINVAL;
-
-       req->sync.off = READ_ONCE(sqe->off);
-       req->sync.len = READ_ONCE(sqe->len);
-       req->sync.flags = READ_ONCE(sqe->sync_range_flags);
-       return 0;
-}
-
-static void io_sync_file_range_finish(struct io_wq_work **workptr)
+static void io_fallocate_finish(struct io_wq_work **workptr)
 {
        struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
        struct io_kiocb *nxt = NULL;
@@ -2128,8 +2515,8 @@ static void io_sync_file_range_finish(struct io_wq_work **workptr)
        if (io_req_cancelled(req))
                return;
 
-       ret = sync_file_range(req->file, req->sync.off, req->sync.len,
-                               req->sync.flags);
+       ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
+                               req->sync.len);
        if (ret < 0)
                req_set_fail_links(req);
        io_cqring_add_event(req, ret);
@@ -2138,53 +2525,499 @@ static void io_sync_file_range_finish(struct io_wq_work **workptr)
                io_wq_assign_next(workptr, nxt);
 }
 
-static int io_sync_file_range(struct io_kiocb *req, struct io_kiocb **nxt,
-                             bool force_nonblock)
+static int io_fallocate_prep(struct io_kiocb *req,
+                            const struct io_uring_sqe *sqe)
+{
+       if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
+               return -EINVAL;
+
+       req->sync.off = READ_ONCE(sqe->off);
+       req->sync.len = READ_ONCE(sqe->addr);
+       req->sync.mode = READ_ONCE(sqe->len);
+       return 0;
+}
+
+static int io_fallocate(struct io_kiocb *req, struct io_kiocb **nxt,
+                       bool force_nonblock)
 {
        struct io_wq_work *work, *old_work;
 
-       /* sync_file_range always requires a blocking context */
+       /* fallocate always requiring blocking context */
        if (force_nonblock) {
                io_put_req(req);
-               req->work.func = io_sync_file_range_finish;
+               req->work.func = io_fallocate_finish;
                return -EAGAIN;
        }
 
        work = old_work = &req->work;
-       io_sync_file_range_finish(&work);
+       io_fallocate_finish(&work);
        if (work && work != old_work)
                *nxt = container_of(work, struct io_kiocb, work);
+
        return 0;
 }
 
-#if defined(CONFIG_NET)
-static void io_sendrecv_async(struct io_wq_work **workptr)
+static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
-       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
-       struct iovec *iov = NULL;
+       const char __user *fname;
+       int ret;
 
-       if (req->io->rw.iov != req->io->rw.fast_iov)
-               iov = req->io->msg.iov;
-       io_wq_submit_work(workptr);
-       kfree(iov);
-}
-#endif
+       if (sqe->ioprio || sqe->buf_index)
+               return -EINVAL;
+       if (sqe->flags & IOSQE_FIXED_FILE)
+               return -EBADF;
+       if (req->flags & REQ_F_NEED_CLEANUP)
+               return 0;
 
-static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
-#if defined(CONFIG_NET)
+       req->open.dfd = READ_ONCE(sqe->fd);
+       req->open.how.mode = READ_ONCE(sqe->len);
+       fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       req->open.how.flags = READ_ONCE(sqe->open_flags);
+
+       req->open.filename = getname(fname);
+       if (IS_ERR(req->open.filename)) {
+               ret = PTR_ERR(req->open.filename);
+               req->open.filename = NULL;
+               return ret;
+       }
+
+       req->flags |= REQ_F_NEED_CLEANUP;
+       return 0;
+}
+
+static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       struct open_how __user *how;
+       const char __user *fname;
+       size_t len;
+       int ret;
+
+       if (sqe->ioprio || sqe->buf_index)
+               return -EINVAL;
+       if (sqe->flags & IOSQE_FIXED_FILE)
+               return -EBADF;
+       if (req->flags & REQ_F_NEED_CLEANUP)
+               return 0;
+
+       req->open.dfd = READ_ONCE(sqe->fd);
+       fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+       len = READ_ONCE(sqe->len);
+
+       if (len < OPEN_HOW_SIZE_VER0)
+               return -EINVAL;
+
+       ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
+                                       len);
+       if (ret)
+               return ret;
+
+       if (!(req->open.how.flags & O_PATH) && force_o_largefile())
+               req->open.how.flags |= O_LARGEFILE;
+
+       req->open.filename = getname(fname);
+       if (IS_ERR(req->open.filename)) {
+               ret = PTR_ERR(req->open.filename);
+               req->open.filename = NULL;
+               return ret;
+       }
+
+       req->flags |= REQ_F_NEED_CLEANUP;
+       return 0;
+}
+
+static int io_openat2(struct io_kiocb *req, struct io_kiocb **nxt,
+                     bool force_nonblock)
+{
+       struct open_flags op;
+       struct file *file;
+       int ret;
+
+       if (force_nonblock)
+               return -EAGAIN;
+
+       ret = build_open_flags(&req->open.how, &op);
+       if (ret)
+               goto err;
+
+       ret = get_unused_fd_flags(req->open.how.flags);
+       if (ret < 0)
+               goto err;
+
+       file = do_filp_open(req->open.dfd, req->open.filename, &op);
+       if (IS_ERR(file)) {
+               put_unused_fd(ret);
+               ret = PTR_ERR(file);
+       } else {
+               fsnotify_open(file);
+               fd_install(ret, file);
+       }
+err:
+       putname(req->open.filename);
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, nxt);
+       return 0;
+}
+
+static int io_openat(struct io_kiocb *req, struct io_kiocb **nxt,
+                    bool force_nonblock)
+{
+       req->open.how = build_open_how(req->open.how.flags, req->open.how.mode);
+       return io_openat2(req, nxt, force_nonblock);
+}
+
+static int io_epoll_ctl_prep(struct io_kiocb *req,
+                            const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_EPOLL)
+       if (sqe->ioprio || sqe->buf_index)
+               return -EINVAL;
+
+       req->epoll.epfd = READ_ONCE(sqe->fd);
+       req->epoll.op = READ_ONCE(sqe->len);
+       req->epoll.fd = READ_ONCE(sqe->off);
+
+       if (ep_op_has_event(req->epoll.op)) {
+               struct epoll_event __user *ev;
+
+               ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
+               if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
+                       return -EFAULT;
+       }
+
+       return 0;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+static int io_epoll_ctl(struct io_kiocb *req, struct io_kiocb **nxt,
+                       bool force_nonblock)
+{
+#if defined(CONFIG_EPOLL)
+       struct io_epoll *ie = &req->epoll;
+       int ret;
+
+       ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
+       if (force_nonblock && ret == -EAGAIN)
+               return -EAGAIN;
+
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, nxt);
+       return 0;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+       if (sqe->ioprio || sqe->buf_index || sqe->off)
+               return -EINVAL;
+
+       req->madvise.addr = READ_ONCE(sqe->addr);
+       req->madvise.len = READ_ONCE(sqe->len);
+       req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
+       return 0;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise(struct io_kiocb *req, struct io_kiocb **nxt,
+                     bool force_nonblock)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+       struct io_madvise *ma = &req->madvise;
+       int ret;
+
+       if (force_nonblock)
+               return -EAGAIN;
+
+       ret = do_madvise(ma->addr, ma->len, ma->advice);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, nxt);
+       return 0;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       if (sqe->ioprio || sqe->buf_index || sqe->addr)
+               return -EINVAL;
+
+       req->fadvise.offset = READ_ONCE(sqe->off);
+       req->fadvise.len = READ_ONCE(sqe->len);
+       req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
+       return 0;
+}
+
+static int io_fadvise(struct io_kiocb *req, struct io_kiocb **nxt,
+                     bool force_nonblock)
+{
+       struct io_fadvise *fa = &req->fadvise;
+       int ret;
+
+       if (force_nonblock) {
+               switch (fa->advice) {
+               case POSIX_FADV_NORMAL:
+               case POSIX_FADV_RANDOM:
+               case POSIX_FADV_SEQUENTIAL:
+                       break;
+               default:
+                       return -EAGAIN;
+               }
+       }
+
+       ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, nxt);
+       return 0;
+}
+
+static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       const char __user *fname;
+       unsigned lookup_flags;
+       int ret;
+
+       if (sqe->ioprio || sqe->buf_index)
+               return -EINVAL;
+       if (sqe->flags & IOSQE_FIXED_FILE)
+               return -EBADF;
+       if (req->flags & REQ_F_NEED_CLEANUP)
+               return 0;
+
+       req->open.dfd = READ_ONCE(sqe->fd);
+       req->open.mask = READ_ONCE(sqe->len);
+       fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       req->open.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+       req->open.how.flags = READ_ONCE(sqe->statx_flags);
+
+       if (vfs_stat_set_lookup_flags(&lookup_flags, req->open.how.flags))
+               return -EINVAL;
+
+       req->open.filename = getname_flags(fname, lookup_flags, NULL);
+       if (IS_ERR(req->open.filename)) {
+               ret = PTR_ERR(req->open.filename);
+               req->open.filename = NULL;
+               return ret;
+       }
+
+       req->flags |= REQ_F_NEED_CLEANUP;
+       return 0;
+}
+
+static int io_statx(struct io_kiocb *req, struct io_kiocb **nxt,
+                   bool force_nonblock)
+{
+       struct io_open *ctx = &req->open;
+       unsigned lookup_flags;
+       struct path path;
+       struct kstat stat;
+       int ret;
+
+       if (force_nonblock)
+               return -EAGAIN;
+
+       if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->how.flags))
+               return -EINVAL;
+
+retry:
+       /* filename_lookup() drops it, keep a reference */
+       ctx->filename->refcnt++;
+
+       ret = filename_lookup(ctx->dfd, ctx->filename, lookup_flags, &path,
+                               NULL);
+       if (ret)
+               goto err;
+
+       ret = vfs_getattr(&path, &stat, ctx->mask, ctx->how.flags);
+       path_put(&path);
+       if (retry_estale(ret, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
+       if (!ret)
+               ret = cp_statx(&stat, ctx->buffer);
+err:
+       putname(ctx->filename);
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, nxt);
+       return 0;
+}
+
+static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       /*
+        * If we queue this for async, it must not be cancellable. That would
+        * leave the 'file' in an undeterminate state.
+        */
+       req->work.flags |= IO_WQ_WORK_NO_CANCEL;
+
+       if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
+           sqe->rw_flags || sqe->buf_index)
+               return -EINVAL;
+       if (sqe->flags & IOSQE_FIXED_FILE)
+               return -EBADF;
+
+       req->close.fd = READ_ONCE(sqe->fd);
+       if (req->file->f_op == &io_uring_fops ||
+           req->close.fd == req->ctx->ring_fd)
+               return -EBADF;
+
+       return 0;
+}
+
+/* only called when __close_fd_get_file() is done */
+static void __io_close_finish(struct io_kiocb *req, struct io_kiocb **nxt)
+{
+       int ret;
+
+       ret = filp_close(req->close.put_file, req->work.files);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       fput(req->close.put_file);
+       io_put_req_find_next(req, nxt);
+}
+
+static void io_close_finish(struct io_wq_work **workptr)
+{
+       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
+       struct io_kiocb *nxt = NULL;
+
+       /* not cancellable, don't do io_req_cancelled() */
+       __io_close_finish(req, &nxt);
+       if (nxt)
+               io_wq_assign_next(workptr, nxt);
+}
+
+static int io_close(struct io_kiocb *req, struct io_kiocb **nxt,
+                   bool force_nonblock)
+{
+       int ret;
+
+       req->close.put_file = NULL;
+       ret = __close_fd_get_file(req->close.fd, &req->close.put_file);
+       if (ret < 0)
+               return ret;
+
+       /* if the file has a flush method, be safe and punt to async */
+       if (req->close.put_file->f_op->flush && !io_wq_current_is_worker())
+               goto eagain;
+
+       /*
+        * No ->flush(), safely close from here and just punt the
+        * fput() to async context.
+        */
+       __io_close_finish(req, nxt);
+       return 0;
+eagain:
+       req->work.func = io_close_finish;
+       /*
+        * Do manual async queue here to avoid grabbing files - we don't
+        * need the files, and it'll cause io_close_finish() to close
+        * the file again and cause a double CQE entry for this request
+        */
+       io_queue_async_work(req);
+       return 0;
+}
+
+static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       struct io_ring_ctx *ctx = req->ctx;
+
+       if (!req->file)
+               return -EBADF;
+
+       if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+               return -EINVAL;
+       if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
+               return -EINVAL;
+
+       req->sync.off = READ_ONCE(sqe->off);
+       req->sync.len = READ_ONCE(sqe->len);
+       req->sync.flags = READ_ONCE(sqe->sync_range_flags);
+       return 0;
+}
+
+static void io_sync_file_range_finish(struct io_wq_work **workptr)
+{
+       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
+       struct io_kiocb *nxt = NULL;
+       int ret;
+
+       if (io_req_cancelled(req))
+               return;
+
+       ret = sync_file_range(req->file, req->sync.off, req->sync.len,
+                               req->sync.flags);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, &nxt);
+       if (nxt)
+               io_wq_assign_next(workptr, nxt);
+}
+
+static int io_sync_file_range(struct io_kiocb *req, struct io_kiocb **nxt,
+                             bool force_nonblock)
+{
+       struct io_wq_work *work, *old_work;
+
+       /* sync_file_range always requires a blocking context */
+       if (force_nonblock) {
+               io_put_req(req);
+               req->work.func = io_sync_file_range_finish;
+               return -EAGAIN;
+       }
+
+       work = old_work = &req->work;
+       io_sync_file_range_finish(&work);
+       if (work && work != old_work)
+               *nxt = container_of(work, struct io_kiocb, work);
+       return 0;
+}
+
+static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_NET)
        struct io_sr_msg *sr = &req->sr_msg;
        struct io_async_ctx *io = req->io;
+       int ret;
 
        sr->msg_flags = READ_ONCE(sqe->msg_flags);
        sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       sr->len = READ_ONCE(sqe->len);
 
-       if (!io)
+       if (!io || req->opcode == IORING_OP_SEND)
+               return 0;
+       /* iovec is already imported */
+       if (req->flags & REQ_F_NEED_CLEANUP)
                return 0;
 
        io->msg.iov = io->msg.fast_iov;
-       return sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
+       ret = sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
                                        &io->msg.iov);
+       if (!ret)
+               req->flags |= REQ_F_NEED_CLEANUP;
+       return ret;
 #else
        return -EOPNOTSUPP;
 #endif
@@ -2204,12 +3037,11 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
        sock = sock_from_file(req->file, &ret);
        if (sock) {
                struct io_async_ctx io;
-               struct sockaddr_storage addr;
                unsigned flags;
 
                if (req->io) {
                        kmsg = &req->io->msg;
-                       kmsg->msg.msg_name = &addr;
+                       kmsg->msg.msg_name = &req->io->msg.addr;
                        /* if iov is set, it's allocated already */
                        if (!kmsg->iov)
                                kmsg->iov = kmsg->fast_iov;
@@ -2218,7 +3050,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
                        struct io_sr_msg *sr = &req->sr_msg;
 
                        kmsg = &io.msg;
-                       kmsg->msg.msg_name = &addr;
+                       kmsg->msg.msg_name = &io.msg.addr;
 
                        io.msg.iov = io.msg.fast_iov;
                        ret = sendmsg_copy_msghdr(&io.msg.msg, sr->msg,
@@ -2237,18 +3069,73 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
                if (force_nonblock && ret == -EAGAIN) {
                        if (req->io)
                                return -EAGAIN;
-                       if (io_alloc_async_ctx(req))
+                       if (io_alloc_async_ctx(req)) {
+                               if (kmsg->iov != kmsg->fast_iov)
+                                       kfree(kmsg->iov);
                                return -ENOMEM;
+                       }
+                       req->flags |= REQ_F_NEED_CLEANUP;
                        memcpy(&req->io->msg, &io.msg, sizeof(io.msg));
-                       req->work.func = io_sendrecv_async;
                        return -EAGAIN;
                }
                if (ret == -ERESTARTSYS)
                        ret = -EINTR;
        }
 
-       if (!io_wq_current_is_worker() && kmsg && kmsg->iov != kmsg->fast_iov)
+       if (kmsg && kmsg->iov != kmsg->fast_iov)
                kfree(kmsg->iov);
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       io_cqring_add_event(req, ret);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_put_req_find_next(req, nxt);
+       return 0;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+static int io_send(struct io_kiocb *req, struct io_kiocb **nxt,
+                  bool force_nonblock)
+{
+#if defined(CONFIG_NET)
+       struct socket *sock;
+       int ret;
+
+       if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+               return -EINVAL;
+
+       sock = sock_from_file(req->file, &ret);
+       if (sock) {
+               struct io_sr_msg *sr = &req->sr_msg;
+               struct msghdr msg;
+               struct iovec iov;
+               unsigned flags;
+
+               ret = import_single_range(WRITE, sr->buf, sr->len, &iov,
+                                               &msg.msg_iter);
+               if (ret)
+                       return ret;
+
+               msg.msg_name = NULL;
+               msg.msg_control = NULL;
+               msg.msg_controllen = 0;
+               msg.msg_namelen = 0;
+
+               flags = req->sr_msg.msg_flags;
+               if (flags & MSG_DONTWAIT)
+                       req->flags |= REQ_F_NOWAIT;
+               else if (force_nonblock)
+                       flags |= MSG_DONTWAIT;
+
+               msg.msg_flags = flags;
+               ret = sock_sendmsg(sock, &msg);
+               if (force_nonblock && ret == -EAGAIN)
+                       return -EAGAIN;
+               if (ret == -ERESTARTSYS)
+                       ret = -EINTR;
+       }
+
        io_cqring_add_event(req, ret);
        if (ret < 0)
                req_set_fail_links(req);
@@ -2265,16 +3152,24 @@ static int io_recvmsg_prep(struct io_kiocb *req,
 #if defined(CONFIG_NET)
        struct io_sr_msg *sr = &req->sr_msg;
        struct io_async_ctx *io = req->io;
+       int ret;
 
        sr->msg_flags = READ_ONCE(sqe->msg_flags);
        sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       sr->len = READ_ONCE(sqe->len);
 
-       if (!io)
+       if (!io || req->opcode == IORING_OP_RECV)
+               return 0;
+       /* iovec is already imported */
+       if (req->flags & REQ_F_NEED_CLEANUP)
                return 0;
 
        io->msg.iov = io->msg.fast_iov;
-       return recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
+       ret = recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
                                        &io->msg.uaddr, &io->msg.iov);
+       if (!ret)
+               req->flags |= REQ_F_NEED_CLEANUP;
+       return ret;
 #else
        return -EOPNOTSUPP;
 #endif
@@ -2294,12 +3189,11 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
        sock = sock_from_file(req->file, &ret);
        if (sock) {
                struct io_async_ctx io;
-               struct sockaddr_storage addr;
                unsigned flags;
 
                if (req->io) {
                        kmsg = &req->io->msg;
-                       kmsg->msg.msg_name = &addr;
+                       kmsg->msg.msg_name = &req->io->msg.addr;
                        /* if iov is set, it's allocated already */
                        if (!kmsg->iov)
                                kmsg->iov = kmsg->fast_iov;
@@ -2308,7 +3202,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
                        struct io_sr_msg *sr = &req->sr_msg;
 
                        kmsg = &io.msg;
-                       kmsg->msg.msg_name = &addr;
+                       kmsg->msg.msg_name = &io.msg.addr;
 
                        io.msg.iov = io.msg.fast_iov;
                        ret = recvmsg_copy_msghdr(&io.msg.msg, sr->msg,
@@ -2329,18 +3223,74 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
                if (force_nonblock && ret == -EAGAIN) {
                        if (req->io)
                                return -EAGAIN;
-                       if (io_alloc_async_ctx(req))
+                       if (io_alloc_async_ctx(req)) {
+                               if (kmsg->iov != kmsg->fast_iov)
+                                       kfree(kmsg->iov);
                                return -ENOMEM;
+                       }
                        memcpy(&req->io->msg, &io.msg, sizeof(io.msg));
-                       req->work.func = io_sendrecv_async;
+                       req->flags |= REQ_F_NEED_CLEANUP;
                        return -EAGAIN;
                }
                if (ret == -ERESTARTSYS)
                        ret = -EINTR;
        }
 
-       if (!io_wq_current_is_worker() && kmsg && kmsg->iov != kmsg->fast_iov)
+       if (kmsg && kmsg->iov != kmsg->fast_iov)
                kfree(kmsg->iov);
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+       io_cqring_add_event(req, ret);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_put_req_find_next(req, nxt);
+       return 0;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+static int io_recv(struct io_kiocb *req, struct io_kiocb **nxt,
+                  bool force_nonblock)
+{
+#if defined(CONFIG_NET)
+       struct socket *sock;
+       int ret;
+
+       if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+               return -EINVAL;
+
+       sock = sock_from_file(req->file, &ret);
+       if (sock) {
+               struct io_sr_msg *sr = &req->sr_msg;
+               struct msghdr msg;
+               struct iovec iov;
+               unsigned flags;
+
+               ret = import_single_range(READ, sr->buf, sr->len, &iov,
+                                               &msg.msg_iter);
+               if (ret)
+                       return ret;
+
+               msg.msg_name = NULL;
+               msg.msg_control = NULL;
+               msg.msg_controllen = 0;
+               msg.msg_namelen = 0;
+               msg.msg_iocb = NULL;
+               msg.msg_flags = 0;
+
+               flags = req->sr_msg.msg_flags;
+               if (flags & MSG_DONTWAIT)
+                       req->flags |= REQ_F_NOWAIT;
+               else if (force_nonblock)
+                       flags |= MSG_DONTWAIT;
+
+               ret = sock_recvmsg(sock, &msg, flags);
+               if (force_nonblock && ret == -EAGAIN)
+                       return -EAGAIN;
+               if (ret == -ERESTARTSYS)
+                       ret = -EINTR;
+       }
+
        io_cqring_add_event(req, ret);
        if (ret < 0)
                req_set_fail_links(req);
@@ -2351,6 +3301,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 #endif
 }
 
+
 static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 #if defined(CONFIG_NET)
@@ -2414,7 +3365,6 @@ static int io_accept(struct io_kiocb *req, struct io_kiocb **nxt,
        ret = __io_accept(req, nxt, force_nonblock);
        if (ret == -EAGAIN && force_nonblock) {
                req->work.func = io_accept_finish;
-               req->work.flags |= IO_WQ_WORK_NEEDS_FILES;
                io_put_req(req);
                return -EAGAIN;
        }
@@ -2635,6 +3585,47 @@ static void io_poll_complete_work(struct io_wq_work **workptr)
                io_wq_assign_next(workptr, nxt);
 }
 
+static void __io_poll_flush(struct io_ring_ctx *ctx, struct llist_node *nodes)
+{
+       struct io_kiocb *req, *tmp;
+       struct req_batch rb;
+
+       rb.to_free = rb.need_iter = 0;
+       spin_lock_irq(&ctx->completion_lock);
+       llist_for_each_entry_safe(req, tmp, nodes, llist_node) {
+               hash_del(&req->hash_node);
+               io_poll_complete(req, req->result, 0);
+
+               if (refcount_dec_and_test(&req->refs) &&
+                   !io_req_multi_free(&rb, req)) {
+                       req->flags |= REQ_F_COMP_LOCKED;
+                       io_free_req(req);
+               }
+       }
+       spin_unlock_irq(&ctx->completion_lock);
+
+       io_cqring_ev_posted(ctx);
+       io_free_req_many(ctx, &rb);
+}
+
+static void io_poll_flush(struct io_wq_work **workptr)
+{
+       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
+       struct llist_node *nodes;
+
+       nodes = llist_del_all(&req->ctx->poll_llist);
+       if (nodes)
+               __io_poll_flush(req->ctx, nodes);
+}
+
+static void io_poll_trigger_evfd(struct io_wq_work **workptr)
+{
+       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
+
+       eventfd_signal(req->ctx->cq_ev_fd, 1);
+       io_put_req(req);
+}
+
 static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
                        void *key)
 {
@@ -2642,7 +3633,6 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
        struct io_kiocb *req = container_of(poll, struct io_kiocb, poll);
        struct io_ring_ctx *ctx = req->ctx;
        __poll_t mask = key_to_poll(key);
-       unsigned long flags;
 
        /* for instances that support it check for an event match first: */
        if (mask && !(mask & poll->events))
@@ -2656,17 +3646,39 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
         * If we have a link timeout we're going to need the completion_lock
         * for finalizing the request, mark us as having grabbed that already.
         */
-       if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) {
-               hash_del(&req->hash_node);
-               io_poll_complete(req, mask, 0);
-               req->flags |= REQ_F_COMP_LOCKED;
-               io_put_req(req);
-               spin_unlock_irqrestore(&ctx->completion_lock, flags);
+       if (mask) {
+               unsigned long flags;
 
-               io_cqring_ev_posted(ctx);
-       } else {
-               io_queue_async_work(req);
+               if (llist_empty(&ctx->poll_llist) &&
+                   spin_trylock_irqsave(&ctx->completion_lock, flags)) {
+                       bool trigger_ev;
+
+                       hash_del(&req->hash_node);
+                       io_poll_complete(req, mask, 0);
+
+                       trigger_ev = io_should_trigger_evfd(ctx);
+                       if (trigger_ev && eventfd_signal_count()) {
+                               trigger_ev = false;
+                               req->work.func = io_poll_trigger_evfd;
+                       } else {
+                               req->flags |= REQ_F_COMP_LOCKED;
+                               io_put_req(req);
+                               req = NULL;
+                       }
+                       spin_unlock_irqrestore(&ctx->completion_lock, flags);
+                       __io_cqring_ev_posted(ctx, trigger_ev);
+               } else {
+                       req->result = mask;
+                       req->llist_node.next = NULL;
+                       /* if the list wasn't empty, we're done */
+                       if (!llist_add(&req->llist_node, &ctx->poll_llist))
+                               req = NULL;
+                       else
+                               req->work.func = io_poll_flush;
+               }
        }
+       if (req)
+               io_queue_async_work(req);
 
        return 1;
 }
@@ -3071,20 +4083,67 @@ static int io_async_cancel(struct io_kiocb *req, struct io_kiocb **nxt)
        return 0;
 }
 
+static int io_files_update_prep(struct io_kiocb *req,
+                               const struct io_uring_sqe *sqe)
+{
+       if (sqe->flags || sqe->ioprio || sqe->rw_flags)
+               return -EINVAL;
+
+       req->files_update.offset = READ_ONCE(sqe->off);
+       req->files_update.nr_args = READ_ONCE(sqe->len);
+       if (!req->files_update.nr_args)
+               return -EINVAL;
+       req->files_update.arg = READ_ONCE(sqe->addr);
+       return 0;
+}
+
+static int io_files_update(struct io_kiocb *req, bool force_nonblock)
+{
+       struct io_ring_ctx *ctx = req->ctx;
+       struct io_uring_files_update up;
+       int ret;
+
+       if (force_nonblock)
+               return -EAGAIN;
+
+       up.offset = req->files_update.offset;
+       up.fds = req->files_update.arg;
+
+       mutex_lock(&ctx->uring_lock);
+       ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
+       mutex_unlock(&ctx->uring_lock);
+
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req(req);
+       return 0;
+}
+
 static int io_req_defer_prep(struct io_kiocb *req,
                             const struct io_uring_sqe *sqe)
 {
        ssize_t ret = 0;
 
+       if (io_op_defs[req->opcode].file_table) {
+               ret = io_grab_files(req);
+               if (unlikely(ret))
+                       return ret;
+       }
+
+       io_req_work_grab_env(req, &io_op_defs[req->opcode]);
+
        switch (req->opcode) {
        case IORING_OP_NOP:
                break;
        case IORING_OP_READV:
        case IORING_OP_READ_FIXED:
+       case IORING_OP_READ:
                ret = io_read_prep(req, sqe, true);
                break;
        case IORING_OP_WRITEV:
        case IORING_OP_WRITE_FIXED:
+       case IORING_OP_WRITE:
                ret = io_write_prep(req, sqe, true);
                break;
        case IORING_OP_POLL_ADD:
@@ -3100,9 +4159,11 @@ static int io_req_defer_prep(struct io_kiocb *req,
                ret = io_prep_sfr(req, sqe);
                break;
        case IORING_OP_SENDMSG:
+       case IORING_OP_SEND:
                ret = io_sendmsg_prep(req, sqe);
                break;
        case IORING_OP_RECVMSG:
+       case IORING_OP_RECV:
                ret = io_recvmsg_prep(req, sqe);
                break;
        case IORING_OP_CONNECT:
@@ -3123,6 +4184,33 @@ static int io_req_defer_prep(struct io_kiocb *req,
        case IORING_OP_ACCEPT:
                ret = io_accept_prep(req, sqe);
                break;
+       case IORING_OP_FALLOCATE:
+               ret = io_fallocate_prep(req, sqe);
+               break;
+       case IORING_OP_OPENAT:
+               ret = io_openat_prep(req, sqe);
+               break;
+       case IORING_OP_CLOSE:
+               ret = io_close_prep(req, sqe);
+               break;
+       case IORING_OP_FILES_UPDATE:
+               ret = io_files_update_prep(req, sqe);
+               break;
+       case IORING_OP_STATX:
+               ret = io_statx_prep(req, sqe);
+               break;
+       case IORING_OP_FADVISE:
+               ret = io_fadvise_prep(req, sqe);
+               break;
+       case IORING_OP_MADVISE:
+               ret = io_madvise_prep(req, sqe);
+               break;
+       case IORING_OP_OPENAT2:
+               ret = io_openat2_prep(req, sqe);
+               break;
+       case IORING_OP_EPOLL_CTL:
+               ret = io_epoll_ctl_prep(req, sqe);
+               break;
        default:
                printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
                                req->opcode);
@@ -3161,6 +4249,35 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        return -EIOCBQUEUED;
 }
 
+static void io_cleanup_req(struct io_kiocb *req)
+{
+       struct io_async_ctx *io = req->io;
+
+       switch (req->opcode) {
+       case IORING_OP_READV:
+       case IORING_OP_READ_FIXED:
+       case IORING_OP_READ:
+       case IORING_OP_WRITEV:
+       case IORING_OP_WRITE_FIXED:
+       case IORING_OP_WRITE:
+               if (io->rw.iov != io->rw.fast_iov)
+                       kfree(io->rw.iov);
+               break;
+       case IORING_OP_SENDMSG:
+       case IORING_OP_RECVMSG:
+               if (io->msg.iov != io->msg.fast_iov)
+                       kfree(io->msg.iov);
+               break;
+       case IORING_OP_OPENAT:
+       case IORING_OP_OPENAT2:
+       case IORING_OP_STATX:
+               putname(req->open.filename);
+               break;
+       }
+
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+}
+
 static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                        struct io_kiocb **nxt, bool force_nonblock)
 {
@@ -3173,6 +4290,7 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                break;
        case IORING_OP_READV:
        case IORING_OP_READ_FIXED:
+       case IORING_OP_READ:
                if (sqe) {
                        ret = io_read_prep(req, sqe, force_nonblock);
                        if (ret < 0)
@@ -3182,6 +4300,7 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                break;
        case IORING_OP_WRITEV:
        case IORING_OP_WRITE_FIXED:
+       case IORING_OP_WRITE:
                if (sqe) {
                        ret = io_write_prep(req, sqe, force_nonblock);
                        if (ret < 0)
@@ -3222,20 +4341,28 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                ret = io_sync_file_range(req, nxt, force_nonblock);
                break;
        case IORING_OP_SENDMSG:
+       case IORING_OP_SEND:
                if (sqe) {
                        ret = io_sendmsg_prep(req, sqe);
                        if (ret < 0)
                                break;
                }
-               ret = io_sendmsg(req, nxt, force_nonblock);
+               if (req->opcode == IORING_OP_SENDMSG)
+                       ret = io_sendmsg(req, nxt, force_nonblock);
+               else
+                       ret = io_send(req, nxt, force_nonblock);
                break;
        case IORING_OP_RECVMSG:
+       case IORING_OP_RECV:
                if (sqe) {
                        ret = io_recvmsg_prep(req, sqe);
                        if (ret)
                                break;
                }
-               ret = io_recvmsg(req, nxt, force_nonblock);
+               if (req->opcode == IORING_OP_RECVMSG)
+                       ret = io_recvmsg(req, nxt, force_nonblock);
+               else
+                       ret = io_recv(req, nxt, force_nonblock);
                break;
        case IORING_OP_TIMEOUT:
                if (sqe) {
@@ -3277,6 +4404,78 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                }
                ret = io_async_cancel(req, nxt);
                break;
+       case IORING_OP_FALLOCATE:
+               if (sqe) {
+                       ret = io_fallocate_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_fallocate(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_OPENAT:
+               if (sqe) {
+                       ret = io_openat_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_openat(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_CLOSE:
+               if (sqe) {
+                       ret = io_close_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_close(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_FILES_UPDATE:
+               if (sqe) {
+                       ret = io_files_update_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_files_update(req, force_nonblock);
+               break;
+       case IORING_OP_STATX:
+               if (sqe) {
+                       ret = io_statx_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_statx(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_FADVISE:
+               if (sqe) {
+                       ret = io_fadvise_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_fadvise(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_MADVISE:
+               if (sqe) {
+                       ret = io_madvise_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_madvise(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_OPENAT2:
+               if (sqe) {
+                       ret = io_openat2_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_openat2(req, nxt, force_nonblock);
+               break;
+       case IORING_OP_EPOLL_CTL:
+               if (sqe) {
+                       ret = io_epoll_ctl_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_epoll_ctl(req, nxt, force_nonblock);
+               break;
        default:
                ret = -EINVAL;
                break;
@@ -3311,11 +4510,13 @@ static void io_wq_submit_work(struct io_wq_work **workptr)
        struct io_kiocb *nxt = NULL;
        int ret = 0;
 
-       if (work->flags & IO_WQ_WORK_CANCEL)
+       /* if NO_CANCEL is set, we must still run the work */
+       if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
+                               IO_WQ_WORK_CANCEL) {
                ret = -ECANCELED;
+       }
 
        if (!ret) {
-               req->has_user = (work->flags & IO_WQ_WORK_HAS_MM) != 0;
                req->in_async = true;
                do {
                        ret = io_issue_sqe(req, NULL, &nxt, false);
@@ -3344,26 +4545,13 @@ static void io_wq_submit_work(struct io_wq_work **workptr)
                io_wq_assign_next(workptr, nxt);
 }
 
-static bool io_req_op_valid(int op)
-{
-       return op >= IORING_OP_NOP && op < IORING_OP_LAST;
-}
-
-static int io_req_needs_file(struct io_kiocb *req)
+static int io_req_needs_file(struct io_kiocb *req, int fd)
 {
-       switch (req->opcode) {
-       case IORING_OP_NOP:
-       case IORING_OP_POLL_REMOVE:
-       case IORING_OP_TIMEOUT:
-       case IORING_OP_TIMEOUT_REMOVE:
-       case IORING_OP_ASYNC_CANCEL:
-       case IORING_OP_LINK_TIMEOUT:
+       if (!io_op_defs[req->opcode].needs_file)
                return 0;
-       default:
-               if (io_req_op_valid(req->opcode))
-                       return 1;
-               return -EINVAL;
-       }
+       if ((fd == -1 || fd == AT_FDCWD) && io_op_defs[req->opcode].fd_non_neg)
+               return 0;
+       return 1;
 }
 
 static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
@@ -3371,8 +4559,8 @@ static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
 {
        struct fixed_file_table *table;
 
-       table = &ctx->file_table[index >> IORING_FILE_TABLE_SHIFT];
-       return table->files[index & IORING_FILE_TABLE_MASK];
+       table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
+       return table->files[index & IORING_FILE_TABLE_MASK];;
 }
 
 static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
@@ -3380,20 +4568,16 @@ static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
 {
        struct io_ring_ctx *ctx = req->ctx;
        unsigned flags;
-       int fd, ret;
+       int fd;
 
        flags = READ_ONCE(sqe->flags);
        fd = READ_ONCE(sqe->fd);
 
-       if (flags & IOSQE_IO_DRAIN)
-               req->flags |= REQ_F_IO_DRAIN;
-
-       ret = io_req_needs_file(req);
-       if (ret <= 0)
-               return ret;
+       if (!io_req_needs_file(req, fd))
+               return 0;
 
        if (flags & IOSQE_FIXED_FILE) {
-               if (unlikely(!ctx->file_table ||
+               if (unlikely(!ctx->file_data ||
                    (unsigned) fd >= ctx->nr_user_files))
                        return -EBADF;
                fd = array_index_nospec(fd, ctx->nr_user_files);
@@ -3401,6 +4585,7 @@ static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
                if (!req->file)
                        return -EBADF;
                req->flags |= REQ_F_FIXED_FILE;
+               percpu_ref_get(&ctx->file_data->refs);
        } else {
                if (req->needs_fixed_file)
                        return -EBADF;
@@ -3418,6 +4603,11 @@ static int io_grab_files(struct io_kiocb *req)
        int ret = -EBADF;
        struct io_ring_ctx *ctx = req->ctx;
 
+       if (req->work.files)
+               return 0;
+       if (!ctx->ring_file)
+               return -EBADF;
+
        rcu_read_lock();
        spin_lock_irq(&ctx->inflight_lock);
        /*
@@ -3426,7 +4616,7 @@ static int io_grab_files(struct io_kiocb *req)
         * the fd has changed since we started down this path, and disallow
         * this operation if it has.
         */
-       if (fcheck(req->ring_fd) == req->ring_file) {
+       if (fcheck(ctx->ring_fd) == ctx->ring_file) {
                list_add(&req->inflight_entry, &ctx->inflight_list);
                req->flags |= REQ_F_INFLIGHT;
                req->work.files = current->files;
@@ -3519,11 +4709,21 @@ static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
        struct io_kiocb *linked_timeout;
        struct io_kiocb *nxt = NULL;
+       const struct cred *old_creds = NULL;
        int ret;
 
 again:
        linked_timeout = io_prep_linked_timeout(req);
 
+       if (req->work.creds && req->work.creds != current_cred()) {
+               if (old_creds)
+                       revert_creds(old_creds);
+               if (old_creds == req->work.creds)
+                       old_creds = NULL; /* restored original creds */
+               else
+                       old_creds = override_creds(req->work.creds);
+       }
+
        ret = io_issue_sqe(req, sqe, &nxt, true);
 
        /*
@@ -3532,7 +4732,8 @@ again:
         */
        if (ret == -EAGAIN && (!(req->flags & REQ_F_NOWAIT) ||
            (req->flags & REQ_F_MUST_PUNT))) {
-               if (req->work.flags & IO_WQ_WORK_NEEDS_FILES) {
+punt:
+               if (io_op_defs[req->opcode].file_table) {
                        ret = io_grab_files(req);
                        if (ret)
                                goto err;
@@ -3548,7 +4749,7 @@ again:
 
 err:
        /* drop submission reference */
-       io_put_req(req);
+       io_put_req_find_next(req, &nxt);
 
        if (linked_timeout) {
                if (!ret)
@@ -3567,29 +4768,40 @@ done_req:
        if (nxt) {
                req = nxt;
                nxt = NULL;
+
+               if (req->flags & REQ_F_FORCE_ASYNC)
+                       goto punt;
                goto again;
        }
+       if (old_creds)
+               revert_creds(old_creds);
 }
 
 static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
        int ret;
 
-       if (unlikely(req->ctx->drain_next)) {
-               req->flags |= REQ_F_IO_DRAIN;
-               req->ctx->drain_next = false;
-       }
-       req->ctx->drain_next = (req->flags & REQ_F_DRAIN_LINK);
-
        ret = io_req_defer(req, sqe);
        if (ret) {
                if (ret != -EIOCBQUEUED) {
+fail_req:
                        io_cqring_add_event(req, ret);
                        req_set_fail_links(req);
                        io_double_put_req(req);
                }
-       } else
+       } else if (req->flags & REQ_F_FORCE_ASYNC) {
+               ret = io_req_defer_prep(req, sqe);
+               if (unlikely(ret < 0))
+                       goto fail_req;
+               /*
+                * Never try inline submit of IOSQE_ASYNC is set, go straight
+                * to async execution.
+                */
+               req->work.flags |= IO_WQ_WORK_CONCURRENT;
+               io_queue_async_work(req);
+       } else {
                __io_queue_sqe(req, sqe);
+       }
 }
 
 static inline void io_queue_link_head(struct io_kiocb *req)
@@ -3602,20 +4814,37 @@ static inline void io_queue_link_head(struct io_kiocb *req)
 }
 
 #define SQE_VALID_FLAGS        (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
-                               IOSQE_IO_HARDLINK)
+                               IOSQE_IO_HARDLINK | IOSQE_ASYNC)
 
 static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                          struct io_submit_state *state, struct io_kiocb **link)
 {
        struct io_ring_ctx *ctx = req->ctx;
-       int ret;
+       unsigned int sqe_flags;
+       int ret, id;
+
+       sqe_flags = READ_ONCE(sqe->flags);
 
        /* enforce forwards compatibility on users */
-       if (unlikely(sqe->flags & ~SQE_VALID_FLAGS)) {
+       if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) {
                ret = -EINVAL;
                goto err_req;
        }
 
+       id = READ_ONCE(sqe->personality);
+       if (id) {
+               req->work.creds = idr_find(&ctx->personality_idr, id);
+               if (unlikely(!req->work.creds)) {
+                       ret = -EINVAL;
+                       goto err_req;
+               }
+               get_cred(req->work.creds);
+       }
+
+       /* same numerical values with corresponding REQ_F_*, safe to copy */
+       req->flags |= sqe_flags & (IOSQE_IO_DRAIN|IOSQE_IO_HARDLINK|
+                                       IOSQE_ASYNC);
+
        ret = io_req_set_file(state, req, sqe);
        if (unlikely(ret)) {
 err_req:
@@ -3632,14 +4861,19 @@ err_req:
         * conditions are true (normal request), then just queue it.
         */
        if (*link) {
-               struct io_kiocb *prev = *link;
-
-               if (sqe->flags & IOSQE_IO_DRAIN)
-                       (*link)->flags |= REQ_F_DRAIN_LINK | REQ_F_IO_DRAIN;
-
-               if (sqe->flags & IOSQE_IO_HARDLINK)
-                       req->flags |= REQ_F_HARDLINK;
+               struct io_kiocb *head = *link;
 
+               /*
+                * Taking sequential execution of a link, draining both sides
+                * of the link also fullfils IOSQE_IO_DRAIN semantics for all
+                * requests in the link. So, it drains the head and the
+                * next after the link request. The last one is done via
+                * drain_next flag to persist the effect across calls.
+                */
+               if (sqe_flags & IOSQE_IO_DRAIN) {
+                       head->flags |= REQ_F_IO_DRAIN;
+                       ctx->drain_next = 1;
+               }
                if (io_alloc_async_ctx(req)) {
                        ret = -EAGAIN;
                        goto err_req;
@@ -3648,23 +4882,32 @@ err_req:
                ret = io_req_defer_prep(req, sqe);
                if (ret) {
                        /* fail even hard links since we don't submit */
-                       prev->flags |= REQ_F_FAIL_LINK;
+                       head->flags |= REQ_F_FAIL_LINK;
                        goto err_req;
                }
-               trace_io_uring_link(ctx, req, prev);
-               list_add_tail(&req->link_list, &prev->link_list);
-       } else if (sqe->flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) {
-               req->flags |= REQ_F_LINK;
-               if (sqe->flags & IOSQE_IO_HARDLINK)
-                       req->flags |= REQ_F_HARDLINK;
-
-               INIT_LIST_HEAD(&req->link_list);
-               ret = io_req_defer_prep(req, sqe);
-               if (ret)
-                       req->flags |= REQ_F_FAIL_LINK;
-               *link = req;
+               trace_io_uring_link(ctx, req, head);
+               list_add_tail(&req->link_list, &head->link_list);
+
+               /* last request of a link, enqueue the link */
+               if (!(sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK))) {
+                       io_queue_link_head(head);
+                       *link = NULL;
+               }
        } else {
-               io_queue_sqe(req, sqe);
+               if (unlikely(ctx->drain_next)) {
+                       req->flags |= REQ_F_IO_DRAIN;
+                       req->ctx->drain_next = 0;
+               }
+               if (sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) {
+                       req->flags |= REQ_F_LINK;
+                       INIT_LIST_HEAD(&req->link_list);
+                       ret = io_req_defer_prep(req, sqe);
+                       if (ret)
+                               req->flags |= REQ_F_FAIL_LINK;
+                       *link = req;
+               } else {
+                       io_queue_sqe(req, sqe);
+               }
        }
 
        return true;
@@ -3678,8 +4921,7 @@ static void io_submit_state_end(struct io_submit_state *state)
        blk_finish_plug(&state->plug);
        io_file_put(state);
        if (state->free_reqs)
-               kmem_cache_free_bulk(req_cachep, state->free_reqs,
-                                       &state->reqs[state->cur_req]);
+               kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
 }
 
 /*
@@ -3698,14 +4940,12 @@ static void io_commit_sqring(struct io_ring_ctx *ctx)
 {
        struct io_rings *rings = ctx->rings;
 
-       if (ctx->cached_sq_head != READ_ONCE(rings->sq.head)) {
-               /*
-                * Ensure any loads from the SQEs are done at this point,
-                * since once we write the new head, the application could
-                * write new data to them.
-                */
-               smp_store_release(&rings->sq.head, ctx->cached_sq_head);
-       }
+       /*
+        * Ensure any loads from the SQEs are done at this point,
+        * since once we write the new head, the application could
+        * write new data to them.
+        */
+       smp_store_release(&rings->sq.head, ctx->cached_sq_head);
 }
 
 /*
@@ -3719,7 +4959,6 @@ static void io_commit_sqring(struct io_ring_ctx *ctx)
 static bool io_get_sqring(struct io_ring_ctx *ctx, struct io_kiocb *req,
                          const struct io_uring_sqe **sqe_ptr)
 {
-       struct io_rings *rings = ctx->rings;
        u32 *sq_array = ctx->sq_array;
        unsigned head;
 
@@ -3731,12 +4970,7 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct io_kiocb *req,
         * 2) allows the kernel side to track the head on its own, even
         *    though the application is the one updating it.
         */
-       head = ctx->cached_sq_head;
-       /* make sure SQ entry isn't read before tail */
-       if (unlikely(head == smp_load_acquire(&rings->sq.tail)))
-               return false;
-
-       head = READ_ONCE(sq_array[head & ctx->sq_mask]);
+       head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
        if (likely(head < ctx->sq_entries)) {
                /*
                 * All io need record the previous position, if LINK vs DARIN,
@@ -3754,7 +4988,7 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct io_kiocb *req,
        /* drop invalid entries */
        ctx->cached_sq_head++;
        ctx->cached_sq_dropped++;
-       WRITE_ONCE(rings->sq_dropped, ctx->cached_sq_dropped);
+       WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
        return false;
 }
 
@@ -3768,19 +5002,30 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
        bool mm_fault = false;
 
        /* if we have a backlog and couldn't flush it all, return BUSY */
-       if (!list_empty(&ctx->cq_overflow_list) &&
-           !io_cqring_overflow_flush(ctx, false))
-               return -EBUSY;
+       if (test_bit(0, &ctx->sq_check_overflow)) {
+               if (!list_empty(&ctx->cq_overflow_list) &&
+                   !io_cqring_overflow_flush(ctx, false))
+                       return -EBUSY;
+       }
+
+       /* make sure SQ entry isn't read before tail */
+       nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
+
+       if (!percpu_ref_tryget_many(&ctx->refs, nr))
+               return -EAGAIN;
 
        if (nr > IO_PLUG_THRESHOLD) {
                io_submit_state_start(&state, nr);
                statep = &state;
        }
 
+       ctx->ring_fd = ring_fd;
+       ctx->ring_file = ring_file;
+
        for (i = 0; i < nr; i++) {
                const struct io_uring_sqe *sqe;
                struct io_kiocb *req;
-               unsigned int sqe_flags;
+               int err;
 
                req = io_get_req(ctx, statep);
                if (unlikely(!req)) {
@@ -3789,39 +5034,44 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
                        break;
                }
                if (!io_get_sqring(ctx, req, &sqe)) {
-                       __io_free_req(req);
+                       __io_req_do_free(req);
                        break;
                }
 
-               if (io_req_needs_user(req) && !*mm) {
+               /* will complete beyond this point, count as submitted */
+               submitted++;
+
+               if (unlikely(req->opcode >= IORING_OP_LAST)) {
+                       err = -EINVAL;
+fail_req:
+                       io_cqring_add_event(req, err);
+                       io_double_put_req(req);
+                       break;
+               }
+
+               if (io_op_defs[req->opcode].needs_mm && !*mm) {
                        mm_fault = mm_fault || !mmget_not_zero(ctx->sqo_mm);
-                       if (!mm_fault) {
-                               use_mm(ctx->sqo_mm);
-                               *mm = ctx->sqo_mm;
+                       if (unlikely(mm_fault)) {
+                               err = -EFAULT;
+                               goto fail_req;
                        }
+                       use_mm(ctx->sqo_mm);
+                       *mm = ctx->sqo_mm;
                }
 
-               submitted++;
-               sqe_flags = sqe->flags;
-
-               req->ring_file = ring_file;
-               req->ring_fd = ring_fd;
-               req->has_user = *mm != NULL;
                req->in_async = async;
                req->needs_fixed_file = async;
-               trace_io_uring_submit_sqe(ctx, req->user_data, true, async);
+               trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
+                                               true, async);
                if (!io_submit_sqe(req, sqe, statep, &link))
                        break;
-               /*
-                * If previous wasn't linked and we have a linked command,
-                * that's the end of the chain. Submit the previous link.
-                */
-               if (!(sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) && link) {
-                       io_queue_link_head(link);
-                       link = NULL;
-               }
        }
 
+       if (unlikely(submitted != nr)) {
+               int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
+
+               percpu_ref_put_many(&ctx->refs, nr - ref_used);
+       }
        if (link)
                io_queue_link_head(link);
        if (statep)
@@ -3840,9 +5090,8 @@ static int io_sq_thread(void *data)
        const struct cred *old_cred;
        mm_segment_t old_fs;
        DEFINE_WAIT(wait);
-       unsigned inflight;
        unsigned long timeout;
-       int ret;
+       int ret = 0;
 
        complete(&ctx->completions[1]);
 
@@ -3850,39 +5099,19 @@ static int io_sq_thread(void *data)
        set_fs(USER_DS);
        old_cred = override_creds(ctx->creds);
 
-       ret = timeout = inflight = 0;
+       timeout = jiffies + ctx->sq_thread_idle;
        while (!kthread_should_park()) {
                unsigned int to_submit;
 
-               if (inflight) {
+               if (!list_empty(&ctx->poll_list)) {
                        unsigned nr_events = 0;
 
-                       if (ctx->flags & IORING_SETUP_IOPOLL) {
-                               /*
-                                * inflight is the count of the maximum possible
-                                * entries we submitted, but it can be smaller
-                                * if we dropped some of them. If we don't have
-                                * poll entries available, then we know that we
-                                * have nothing left to poll for. Reset the
-                                * inflight count to zero in that case.
-                                */
-                               mutex_lock(&ctx->uring_lock);
-                               if (!list_empty(&ctx->poll_list))
-                                       __io_iopoll_check(ctx, &nr_events, 0);
-                               else
-                                       inflight = 0;
-                               mutex_unlock(&ctx->uring_lock);
-                       } else {
-                               /*
-                                * Normal IO, just pretend everything completed.
-                                * We don't have to poll completions for that.
-                                */
-                               nr_events = inflight;
-                       }
-
-                       inflight -= nr_events;
-                       if (!inflight)
+                       mutex_lock(&ctx->uring_lock);
+                       if (!list_empty(&ctx->poll_list))
+                               io_iopoll_getevents(ctx, &nr_events, 0);
+                       else
                                timeout = jiffies + ctx->sq_thread_idle;
+                       mutex_unlock(&ctx->uring_lock);
                }
 
                to_submit = io_sqring_entries(ctx);
@@ -3893,19 +5122,6 @@ static int io_sq_thread(void *data)
                 */
                if (!to_submit || ret == -EBUSY) {
                        /*
-                        * We're polling. If we're within the defined idle
-                        * period, then let us spin without work before going
-                        * to sleep. The exception is if we got EBUSY doing
-                        * more IO, we should wait for the application to
-                        * reap events and wake us up.
-                        */
-                       if (inflight ||
-                           (!time_after(jiffies, timeout) && ret != -EBUSY)) {
-                               cond_resched();
-                               continue;
-                       }
-
-                       /*
                         * Drop cur_mm before scheduling, we can't hold it for
                         * long periods (or over schedule()). Do this before
                         * adding ourselves to the waitqueue, as the unuse/drop
@@ -3917,9 +5133,36 @@ static int io_sq_thread(void *data)
                                cur_mm = NULL;
                        }
 
+                       /*
+                        * We're polling. If we're within the defined idle
+                        * period, then let us spin without work before going
+                        * to sleep. The exception is if we got EBUSY doing
+                        * more IO, we should wait for the application to
+                        * reap events and wake us up.
+                        */
+                       if (!list_empty(&ctx->poll_list) ||
+                           (!time_after(jiffies, timeout) && ret != -EBUSY &&
+                           !percpu_ref_is_dying(&ctx->refs))) {
+                               cond_resched();
+                               continue;
+                       }
+
                        prepare_to_wait(&ctx->sqo_wait, &wait,
                                                TASK_INTERRUPTIBLE);
 
+                       /*
+                        * While doing polled IO, before going to sleep, we need
+                        * to check if there are new reqs added to poll_list, it
+                        * is because reqs may have been punted to io worker and
+                        * will be added to poll_list later, hence check the
+                        * poll_list again.
+                        */
+                       if ((ctx->flags & IORING_SETUP_IOPOLL) &&
+                           !list_empty_careful(&ctx->poll_list)) {
+                               finish_wait(&ctx->sqo_wait, &wait);
+                               continue;
+                       }
+
                        /* Tell userspace we may need a wakeup call */
                        ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
                        /* make sure to read SQ tail after writing flags */
@@ -3944,12 +5187,10 @@ static int io_sq_thread(void *data)
                        ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
                }
 
-               to_submit = min(to_submit, ctx->sq_entries);
                mutex_lock(&ctx->uring_lock);
                ret = io_submit_sqes(ctx, to_submit, NULL, -1, &cur_mm, true);
                mutex_unlock(&ctx->uring_lock);
-               if (ret > 0)
-                       inflight += ret;
+               timeout = jiffies + ctx->sq_thread_idle;
        }
 
        set_fs(old_fs);
@@ -4075,19 +5316,35 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 #endif
 }
 
+static void io_file_ref_kill(struct percpu_ref *ref)
+{
+       struct fixed_file_data *data;
+
+       data = container_of(ref, struct fixed_file_data, refs);
+       complete(&data->done);
+}
+
 static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 {
+       struct fixed_file_data *data = ctx->file_data;
        unsigned nr_tables, i;
 
-       if (!ctx->file_table)
+       if (!data)
                return -ENXIO;
 
+       percpu_ref_kill_and_confirm(&data->refs, io_file_ref_kill);
+       flush_work(&data->ref_work);
+       wait_for_completion(&data->done);
+       io_ring_file_ref_flush(data);
+       percpu_ref_exit(&data->refs);
+
        __io_sqe_files_unregister(ctx);
        nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
        for (i = 0; i < nr_tables; i++)
-               kfree(ctx->file_table[i].files);
-       kfree(ctx->file_table);
-       ctx->file_table = NULL;
+               kfree(data->table[i].files);
+       kfree(data->table);
+       kfree(data);
+       ctx->file_data = NULL;
        ctx->nr_user_files = 0;
        return 0;
 }
@@ -4118,16 +5375,6 @@ static void io_finish_async(struct io_ring_ctx *ctx)
 }
 
 #if defined(CONFIG_UNIX)
-static void io_destruct_skb(struct sk_buff *skb)
-{
-       struct io_ring_ctx *ctx = skb->sk->sk_user_data;
-
-       if (ctx->io_wq)
-               io_wq_flush(ctx->io_wq);
-
-       unix_destruct_scm(skb);
-}
-
 /*
  * Ensure the UNIX gc is aware of our file set, so we are certain that
  * the io_uring can be safely unregistered on process exit, even if we have
@@ -4175,7 +5422,7 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
                fpl->max = SCM_MAX_FD;
                fpl->count = nr_files;
                UNIXCB(skb).fp = fpl;
-               skb->destructor = io_destruct_skb;
+               skb->destructor = unix_destruct_scm;
                refcount_add(skb->truesize, &sk->sk_wmem_alloc);
                skb_queue_head(&sk->sk_receive_queue, skb);
 
@@ -4237,7 +5484,7 @@ static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables,
        int i;
 
        for (i = 0; i < nr_tables; i++) {
-               struct fixed_file_table *table = &ctx->file_table[i];
+               struct fixed_file_table *table = &ctx->file_data->table[i];
                unsigned this_files;
 
                this_files = min(nr_files, IORING_MAX_FILES_TABLE);
@@ -4252,101 +5499,15 @@ static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables,
                return 0;
 
        for (i = 0; i < nr_tables; i++) {
-               struct fixed_file_table *table = &ctx->file_table[i];
+               struct fixed_file_table *table = &ctx->file_data->table[i];
                kfree(table->files);
        }
        return 1;
 }
 
-static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
-                                unsigned nr_args)
-{
-       __s32 __user *fds = (__s32 __user *) arg;
-       unsigned nr_tables;
-       int fd, ret = 0;
-       unsigned i;
-
-       if (ctx->file_table)
-               return -EBUSY;
-       if (!nr_args)
-               return -EINVAL;
-       if (nr_args > IORING_MAX_FIXED_FILES)
-               return -EMFILE;
-
-       nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
-       ctx->file_table = kcalloc(nr_tables, sizeof(struct fixed_file_table),
-                                       GFP_KERNEL);
-       if (!ctx->file_table)
-               return -ENOMEM;
-
-       if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) {
-               kfree(ctx->file_table);
-               ctx->file_table = NULL;
-               return -ENOMEM;
-       }
-
-       for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
-               struct fixed_file_table *table;
-               unsigned index;
-
-               ret = -EFAULT;
-               if (copy_from_user(&fd, &fds[i], sizeof(fd)))
-                       break;
-               /* allow sparse sets */
-               if (fd == -1) {
-                       ret = 0;
-                       continue;
-               }
-
-               table = &ctx->file_table[i >> IORING_FILE_TABLE_SHIFT];
-               index = i & IORING_FILE_TABLE_MASK;
-               table->files[index] = fget(fd);
-
-               ret = -EBADF;
-               if (!table->files[index])
-                       break;
-               /*
-                * Don't allow io_uring instances to be registered. If UNIX
-                * isn't enabled, then this causes a reference cycle and this
-                * instance can never get freed. If UNIX is enabled we'll
-                * handle it just fine, but there's still no point in allowing
-                * a ring fd as it doesn't support regular read/write anyway.
-                */
-               if (table->files[index]->f_op == &io_uring_fops) {
-                       fput(table->files[index]);
-                       break;
-               }
-               ret = 0;
-       }
-
-       if (ret) {
-               for (i = 0; i < ctx->nr_user_files; i++) {
-                       struct file *file;
-
-                       file = io_file_from_index(ctx, i);
-                       if (file)
-                               fput(file);
-               }
-               for (i = 0; i < nr_tables; i++)
-                       kfree(ctx->file_table[i].files);
-
-               kfree(ctx->file_table);
-               ctx->file_table = NULL;
-               ctx->nr_user_files = 0;
-               return ret;
-       }
-
-       ret = io_sqe_files_scm(ctx);
-       if (ret)
-               io_sqe_files_unregister(ctx);
-
-       return ret;
-}
-
-static void io_sqe_file_unregister(struct io_ring_ctx *ctx, int index)
+static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
 {
 #if defined(CONFIG_UNIX)
-       struct file *file = io_file_from_index(ctx, index);
        struct sock *sock = ctx->ring_sock->sk;
        struct sk_buff_head list, *head = &sock->sk_receive_queue;
        struct sk_buff *skb;
@@ -4390,20 +5551,177 @@ static void io_sqe_file_unregister(struct io_ring_ctx *ctx, int index)
                if (!file)
                        break;
 
-               __skb_queue_tail(&list, skb);
-
-               skb = skb_dequeue(head);
+               __skb_queue_tail(&list, skb);
+
+               skb = skb_dequeue(head);
+       }
+
+       if (skb_peek(&list)) {
+               spin_lock_irq(&head->lock);
+               while ((skb = __skb_dequeue(&list)) != NULL)
+                       __skb_queue_tail(head, skb);
+               spin_unlock_irq(&head->lock);
+       }
+#else
+       fput(file);
+#endif
+}
+
+struct io_file_put {
+       struct llist_node llist;
+       struct file *file;
+       struct completion *done;
+};
+
+static void io_ring_file_ref_flush(struct fixed_file_data *data)
+{
+       struct io_file_put *pfile, *tmp;
+       struct llist_node *node;
+
+       while ((node = llist_del_all(&data->put_llist)) != NULL) {
+               llist_for_each_entry_safe(pfile, tmp, node, llist) {
+                       io_ring_file_put(data->ctx, pfile->file);
+                       if (pfile->done)
+                               complete(pfile->done);
+                       else
+                               kfree(pfile);
+               }
+       }
+}
+
+static void io_ring_file_ref_switch(struct work_struct *work)
+{
+       struct fixed_file_data *data;
+
+       data = container_of(work, struct fixed_file_data, ref_work);
+       io_ring_file_ref_flush(data);
+       percpu_ref_get(&data->refs);
+       percpu_ref_switch_to_percpu(&data->refs);
+}
+
+static void io_file_data_ref_zero(struct percpu_ref *ref)
+{
+       struct fixed_file_data *data;
+
+       data = container_of(ref, struct fixed_file_data, refs);
+
+       /*
+        * We can't safely switch from inside this context, punt to wq. If
+        * the table ref is going away, the table is being unregistered.
+        * Don't queue up the async work for that case, the caller will
+        * handle it.
+        */
+       if (!percpu_ref_is_dying(&data->refs))
+               queue_work(system_wq, &data->ref_work);
+}
+
+static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
+                                unsigned nr_args)
+{
+       __s32 __user *fds = (__s32 __user *) arg;
+       unsigned nr_tables;
+       struct file *file;
+       int fd, ret = 0;
+       unsigned i;
+
+       if (ctx->file_data)
+               return -EBUSY;
+       if (!nr_args)
+               return -EINVAL;
+       if (nr_args > IORING_MAX_FIXED_FILES)
+               return -EMFILE;
+
+       ctx->file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
+       if (!ctx->file_data)
+               return -ENOMEM;
+       ctx->file_data->ctx = ctx;
+       init_completion(&ctx->file_data->done);
+
+       nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
+       ctx->file_data->table = kcalloc(nr_tables,
+                                       sizeof(struct fixed_file_table),
+                                       GFP_KERNEL);
+       if (!ctx->file_data->table) {
+               kfree(ctx->file_data);
+               ctx->file_data = NULL;
+               return -ENOMEM;
+       }
+
+       if (percpu_ref_init(&ctx->file_data->refs, io_file_data_ref_zero,
+                               PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {
+               kfree(ctx->file_data->table);
+               kfree(ctx->file_data);
+               ctx->file_data = NULL;
+               return -ENOMEM;
+       }
+       ctx->file_data->put_llist.first = NULL;
+       INIT_WORK(&ctx->file_data->ref_work, io_ring_file_ref_switch);
+
+       if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) {
+               percpu_ref_exit(&ctx->file_data->refs);
+               kfree(ctx->file_data->table);
+               kfree(ctx->file_data);
+               ctx->file_data = NULL;
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
+               struct fixed_file_table *table;
+               unsigned index;
+
+               ret = -EFAULT;
+               if (copy_from_user(&fd, &fds[i], sizeof(fd)))
+                       break;
+               /* allow sparse sets */
+               if (fd == -1) {
+                       ret = 0;
+                       continue;
+               }
+
+               table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
+               index = i & IORING_FILE_TABLE_MASK;
+               file = fget(fd);
+
+               ret = -EBADF;
+               if (!file)
+                       break;
+
+               /*
+                * Don't allow io_uring instances to be registered. If UNIX
+                * isn't enabled, then this causes a reference cycle and this
+                * instance can never get freed. If UNIX is enabled we'll
+                * handle it just fine, but there's still no point in allowing
+                * a ring fd as it doesn't support regular read/write anyway.
+                */
+               if (file->f_op == &io_uring_fops) {
+                       fput(file);
+                       break;
+               }
+               ret = 0;
+               table->files[index] = file;
        }
 
-       if (skb_peek(&list)) {
-               spin_lock_irq(&head->lock);
-               while ((skb = __skb_dequeue(&list)) != NULL)
-                       __skb_queue_tail(head, skb);
-               spin_unlock_irq(&head->lock);
+       if (ret) {
+               for (i = 0; i < ctx->nr_user_files; i++) {
+                       file = io_file_from_index(ctx, i);
+                       if (file)
+                               fput(file);
+               }
+               for (i = 0; i < nr_tables; i++)
+                       kfree(ctx->file_data->table[i].files);
+
+               kfree(ctx->file_data->table);
+               kfree(ctx->file_data);
+               ctx->file_data = NULL;
+               ctx->nr_user_files = 0;
+               return ret;
        }
-#else
-       fput(io_file_from_index(ctx, index));
-#endif
+
+       ret = io_sqe_files_scm(ctx);
+       if (ret)
+               io_sqe_files_unregister(ctx);
+
+       return ret;
 }
 
 static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
@@ -4449,27 +5767,65 @@ static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
 #endif
 }
 
-static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
-                              unsigned nr_args)
+static void io_atomic_switch(struct percpu_ref *ref)
 {
-       struct io_uring_files_update up;
+       struct fixed_file_data *data;
+
+       data = container_of(ref, struct fixed_file_data, refs);
+       clear_bit(FFD_F_ATOMIC, &data->state);
+}
+
+static bool io_queue_file_removal(struct fixed_file_data *data,
+                                 struct file *file)
+{
+       struct io_file_put *pfile, pfile_stack;
+       DECLARE_COMPLETION_ONSTACK(done);
+
+       /*
+        * If we fail allocating the struct we need for doing async reomval
+        * of this file, just punt to sync and wait for it.
+        */
+       pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
+       if (!pfile) {
+               pfile = &pfile_stack;
+               pfile->done = &done;
+       }
+
+       pfile->file = file;
+       llist_add(&pfile->llist, &data->put_llist);
+
+       if (pfile == &pfile_stack) {
+               if (!test_and_set_bit(FFD_F_ATOMIC, &data->state)) {
+                       percpu_ref_put(&data->refs);
+                       percpu_ref_switch_to_atomic(&data->refs,
+                                                       io_atomic_switch);
+               }
+               wait_for_completion(&done);
+               flush_work(&data->ref_work);
+               return false;
+       }
+
+       return true;
+}
+
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+                                struct io_uring_files_update *up,
+                                unsigned nr_args)
+{
+       struct fixed_file_data *data = ctx->file_data;
+       bool ref_switch = false;
+       struct file *file;
        __s32 __user *fds;
        int fd, i, err;
        __u32 done;
 
-       if (!ctx->file_table)
-               return -ENXIO;
-       if (!nr_args)
-               return -EINVAL;
-       if (copy_from_user(&up, arg, sizeof(up)))
-               return -EFAULT;
-       if (check_add_overflow(up.offset, nr_args, &done))
+       if (check_add_overflow(up->offset, nr_args, &done))
                return -EOVERFLOW;
        if (done > ctx->nr_user_files)
                return -EINVAL;
 
        done = 0;
-       fds = (__s32 __user *) up.fds;
+       fds = u64_to_user_ptr(up->fds);
        while (nr_args) {
                struct fixed_file_table *table;
                unsigned index;
@@ -4479,16 +5835,16 @@ static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
                        err = -EFAULT;
                        break;
                }
-               i = array_index_nospec(up.offset, ctx->nr_user_files);
-               table = &ctx->file_table[i >> IORING_FILE_TABLE_SHIFT];
+               i = array_index_nospec(up->offset, ctx->nr_user_files);
+               table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
                index = i & IORING_FILE_TABLE_MASK;
                if (table->files[index]) {
-                       io_sqe_file_unregister(ctx, i);
+                       file = io_file_from_index(ctx, index);
                        table->files[index] = NULL;
+                       if (io_queue_file_removal(data, file))
+                               ref_switch = true;
                }
                if (fd != -1) {
-                       struct file *file;
-
                        file = fget(fd);
                        if (!file) {
                                err = -EBADF;
@@ -4514,11 +5870,32 @@ static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
                }
                nr_args--;
                done++;
-               up.offset++;
+               up->offset++;
+       }
+
+       if (ref_switch && !test_and_set_bit(FFD_F_ATOMIC, &data->state)) {
+               percpu_ref_put(&data->refs);
+               percpu_ref_switch_to_atomic(&data->refs, io_atomic_switch);
        }
 
        return done ? done : err;
 }
+static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
+                              unsigned nr_args)
+{
+       struct io_uring_files_update up;
+
+       if (!ctx->file_data)
+               return -ENXIO;
+       if (!nr_args)
+               return -EINVAL;
+       if (copy_from_user(&up, arg, sizeof(up)))
+               return -EFAULT;
+       if (up.resv)
+               return -EINVAL;
+
+       return __io_sqe_files_update(ctx, &up, nr_args);
+}
 
 static void io_put_work(struct io_wq_work *work)
 {
@@ -4534,11 +5911,56 @@ static void io_get_work(struct io_wq_work *work)
        refcount_inc(&req->refs);
 }
 
+static int io_init_wq_offload(struct io_ring_ctx *ctx,
+                             struct io_uring_params *p)
+{
+       struct io_wq_data data;
+       struct fd f;
+       struct io_ring_ctx *ctx_attach;
+       unsigned int concurrency;
+       int ret = 0;
+
+       data.user = ctx->user;
+       data.get_work = io_get_work;
+       data.put_work = io_put_work;
+
+       if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
+               /* Do QD, or 4 * CPUS, whatever is smallest */
+               concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
+
+               ctx->io_wq = io_wq_create(concurrency, &data);
+               if (IS_ERR(ctx->io_wq)) {
+                       ret = PTR_ERR(ctx->io_wq);
+                       ctx->io_wq = NULL;
+               }
+               return ret;
+       }
+
+       f = fdget(p->wq_fd);
+       if (!f.file)
+               return -EBADF;
+
+       if (f.file->f_op != &io_uring_fops) {
+               ret = -EINVAL;
+               goto out_fput;
+       }
+
+       ctx_attach = f.file->private_data;
+       /* @io_wq is protected by holding the fd */
+       if (!io_wq_get(ctx_attach->io_wq, &data)) {
+               ret = -EINVAL;
+               goto out_fput;
+       }
+
+       ctx->io_wq = ctx_attach->io_wq;
+out_fput:
+       fdput(f);
+       return ret;
+}
+
 static int io_sq_offload_start(struct io_ring_ctx *ctx,
                               struct io_uring_params *p)
 {
-       struct io_wq_data data;
-       unsigned concurrency;
        int ret;
 
        init_waitqueue_head(&ctx->sqo_wait);
@@ -4582,20 +6004,9 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
                goto err;
        }
 
-       data.mm = ctx->sqo_mm;
-       data.user = ctx->user;
-       data.creds = ctx->creds;
-       data.get_work = io_get_work;
-       data.put_work = io_put_work;
-
-       /* Do QD, or 4 * CPUS, whatever is smallest */
-       concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
-       ctx->io_wq = io_wq_create(concurrency, &data);
-       if (IS_ERR(ctx->io_wq)) {
-               ret = PTR_ERR(ctx->io_wq);
-               ctx->io_wq = NULL;
+       ret = io_init_wq_offload(ctx, p);
+       if (ret)
                goto err;
-       }
 
        return 0;
 err:
@@ -4700,7 +6111,7 @@ static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
                struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
 
                for (j = 0; j < imu->nr_bvecs; j++)
-                       put_user_page(imu->bvec[j].bv_page);
+                       unpin_user_page(imu->bvec[j].bv_page);
 
                if (ctx->account_mem)
                        io_unaccount_mem(ctx->user, imu->nr_bvecs);
@@ -4821,7 +6232,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
 
                ret = 0;
                down_read(&current->mm->mmap_sem);
-               pret = get_user_pages(ubuf, nr_pages,
+               pret = pin_user_pages(ubuf, nr_pages,
                                      FOLL_WRITE | FOLL_LONGTERM,
                                      pages, vmas);
                if (pret == nr_pages) {
@@ -4845,7 +6256,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
                         * release any pages we did get
                         */
                        if (pret > 0)
-                               put_user_pages(pages, pret);
+                               unpin_user_pages(pages, pret);
                        if (ctx->account_mem)
                                io_unaccount_mem(ctx->user, nr_pages);
                        kvfree(imu->bvec);
@@ -4923,6 +6334,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
        io_sqe_buffer_unregister(ctx);
        io_sqe_files_unregister(ctx);
        io_eventfd_unregister(ctx);
+       idr_destroy(&ctx->personality_idr);
 
 #if defined(CONFIG_UNIX)
        if (ctx->ring_sock) {
@@ -4960,7 +6372,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait)
        if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head !=
            ctx->rings->sq_ring_entries)
                mask |= EPOLLOUT | EPOLLWRNORM;
-       if (READ_ONCE(ctx->rings->cq.head) != ctx->cached_cq_tail)
+       if (io_cqring_events(ctx, false))
                mask |= EPOLLIN | EPOLLRDNORM;
 
        return mask;
@@ -4973,12 +6385,33 @@ static int io_uring_fasync(int fd, struct file *file, int on)
        return fasync_helper(fd, file, on, &ctx->cq_fasync);
 }
 
+static int io_remove_personalities(int id, void *p, void *data)
+{
+       struct io_ring_ctx *ctx = data;
+       const struct cred *cred;
+
+       cred = idr_remove(&ctx->personality_idr, id);
+       if (cred)
+               put_cred(cred);
+       return 0;
+}
+
 static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
 {
        mutex_lock(&ctx->uring_lock);
        percpu_ref_kill(&ctx->refs);
        mutex_unlock(&ctx->uring_lock);
 
+       /*
+        * Wait for sq thread to idle, if we have one. It won't spin on new
+        * work after we've killed the ctx ref above. This is important to do
+        * before we cancel existing commands, as the thread could otherwise
+        * be queueing new work post that. If that's work we need to cancel,
+        * it could cause shutdown to hang.
+        */
+       while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait))
+               cpu_relax();
+
        io_kill_timeouts(ctx);
        io_poll_remove_all(ctx);
 
@@ -4989,6 +6422,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
        /* if we failed setting up the ctx, we might not have any rings */
        if (ctx->rings)
                io_cqring_overflow_flush(ctx, true);
+       idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
        wait_for_completion(&ctx->completions[0]);
        io_ring_ctx_free(ctx);
 }
@@ -5030,6 +6464,29 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
                if (!cancel_req)
                        break;
 
+               if (cancel_req->flags & REQ_F_OVERFLOW) {
+                       spin_lock_irq(&ctx->completion_lock);
+                       list_del(&cancel_req->list);
+                       cancel_req->flags &= ~REQ_F_OVERFLOW;
+                       if (list_empty(&ctx->cq_overflow_list)) {
+                               clear_bit(0, &ctx->sq_check_overflow);
+                               clear_bit(0, &ctx->cq_check_overflow);
+                       }
+                       spin_unlock_irq(&ctx->completion_lock);
+
+                       WRITE_ONCE(ctx->rings->cq_overflow,
+                               atomic_inc_return(&ctx->cached_cq_overflow));
+
+                       /*
+                        * Put inflight ref and overflow ref. If that's
+                        * all we had, then we're done with this request.
+                        */
+                       if (refcount_sub_and_test(2, &cancel_req->refs)) {
+                               io_put_req(cancel_req);
+                               continue;
+                       }
+               }
+
                io_wq_cancel_work(ctx->io_wq, &cancel_req->work);
                io_put_req(cancel_req);
                schedule();
@@ -5042,10 +6499,13 @@ static int io_uring_flush(struct file *file, void *data)
        struct io_ring_ctx *ctx = file->private_data;
 
        io_uring_cancel_files(ctx, data);
-       if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) {
-               io_cqring_overflow_flush(ctx, true);
-               io_wq_cancel_all(ctx->io_wq);
-       }
+
+       /*
+        * If the task is going away, cancel work it may have pending
+        */
+       if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
+               io_wq_cancel_pid(ctx->io_wq, task_pid_vnr(current));
+
        return 0;
 }
 
@@ -5159,13 +6619,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
        } else if (to_submit) {
                struct mm_struct *cur_mm;
 
-               if (current->mm != ctx->sqo_mm ||
-                   current_cred() != ctx->creds) {
-                       ret = -EPERM;
-                       goto out;
-               }
-
-               to_submit = min(to_submit, ctx->sq_entries);
                mutex_lock(&ctx->uring_lock);
                /* already have mm, so io_submit_sqes() won't try to grab it */
                cur_mm = ctx->sqo_mm;
@@ -5195,6 +6648,80 @@ out_fput:
        return submitted ? submitted : ret;
 }
 
+static int io_uring_show_cred(int id, void *p, void *data)
+{
+       const struct cred *cred = p;
+       struct seq_file *m = data;
+       struct user_namespace *uns = seq_user_ns(m);
+       struct group_info *gi;
+       kernel_cap_t cap;
+       unsigned __capi;
+       int g;
+
+       seq_printf(m, "%5d\n", id);
+       seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
+       seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
+       seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
+       seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
+       seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
+       seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
+       seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
+       seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
+       seq_puts(m, "\n\tGroups:\t");
+       gi = cred->group_info;
+       for (g = 0; g < gi->ngroups; g++) {
+               seq_put_decimal_ull(m, g ? " " : "",
+                                       from_kgid_munged(uns, gi->gid[g]));
+       }
+       seq_puts(m, "\n\tCapEff:\t");
+       cap = cred->cap_effective;
+       CAP_FOR_EACH_U32(__capi)
+               seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
+       seq_putc(m, '\n');
+       return 0;
+}
+
+static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
+{
+       int i;
+
+       mutex_lock(&ctx->uring_lock);
+       seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
+       for (i = 0; i < ctx->nr_user_files; i++) {
+               struct fixed_file_table *table;
+               struct file *f;
+
+               table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
+               f = table->files[i & IORING_FILE_TABLE_MASK];
+               if (f)
+                       seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
+               else
+                       seq_printf(m, "%5u: <none>\n", i);
+       }
+       seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
+       for (i = 0; i < ctx->nr_user_bufs; i++) {
+               struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
+
+               seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
+                                               (unsigned int) buf->len);
+       }
+       if (!idr_is_empty(&ctx->personality_idr)) {
+               seq_printf(m, "Personalities:\n");
+               idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
+       }
+       mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
+{
+       struct io_ring_ctx *ctx = f->private_data;
+
+       if (percpu_ref_tryget(&ctx->refs)) {
+               __io_uring_show_fdinfo(ctx, m);
+               percpu_ref_put(&ctx->refs);
+       }
+}
+
 static const struct file_operations io_uring_fops = {
        .release        = io_uring_release,
        .flush          = io_uring_flush,
@@ -5205,6 +6732,7 @@ static const struct file_operations io_uring_fops = {
 #endif
        .poll           = io_uring_poll,
        .fasync         = io_uring_fasync,
+       .show_fdinfo    = io_uring_show_fdinfo,
 };
 
 static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
@@ -5281,7 +6809,6 @@ static int io_uring_get_fd(struct io_ring_ctx *ctx)
 
 #if defined(CONFIG_UNIX)
        ctx->ring_sock->file = file;
-       ctx->ring_sock->sk->sk_user_data = ctx;
 #endif
        fd_install(ret, file);
        return ret;
@@ -5300,8 +6827,13 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p)
        bool account_mem;
        int ret;
 
-       if (!entries || entries > IORING_MAX_ENTRIES)
+       if (!entries)
                return -EINVAL;
+       if (entries > IORING_MAX_ENTRIES) {
+               if (!(p->flags & IORING_SETUP_CLAMP))
+                       return -EINVAL;
+               entries = IORING_MAX_ENTRIES;
+       }
 
        /*
         * Use twice as many entries for the CQ ring. It's possible for the
@@ -5318,8 +6850,13 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p)
                 * to a power-of-two, if it isn't already. We do NOT impose
                 * any cq vs sq ring sizing.
                 */
-               if (p->cq_entries < p->sq_entries || p->cq_entries > IORING_MAX_CQ_ENTRIES)
+               if (p->cq_entries < p->sq_entries)
                        return -EINVAL;
+               if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
+                       if (!(p->flags & IORING_SETUP_CLAMP))
+                               return -EINVAL;
+                       p->cq_entries = IORING_MAX_CQ_ENTRIES;
+               }
                p->cq_entries = roundup_pow_of_two(p->cq_entries);
        } else {
                p->cq_entries = 2 * p->sq_entries;
@@ -5384,7 +6921,8 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p)
                goto err;
 
        p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
-                       IORING_FEAT_SUBMIT_STABLE;
+                       IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
+                       IORING_FEAT_CUR_PERSONALITY;
        trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
        return ret;
 err:
@@ -5411,7 +6949,8 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
        }
 
        if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
-                       IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE))
+                       IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
+                       IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ))
                return -EINVAL;
 
        ret = io_uring_create(entries, &p);
@@ -5430,6 +6969,84 @@ SYSCALL_DEFINE2(io_uring_setup, u32, entries,
        return io_uring_setup(entries, params);
 }
 
+static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
+{
+       struct io_uring_probe *p;
+       size_t size;
+       int i, ret;
+
+       size = struct_size(p, ops, nr_args);
+       if (size == SIZE_MAX)
+               return -EOVERFLOW;
+       p = kzalloc(size, GFP_KERNEL);
+       if (!p)
+               return -ENOMEM;
+
+       ret = -EFAULT;
+       if (copy_from_user(p, arg, size))
+               goto out;
+       ret = -EINVAL;
+       if (memchr_inv(p, 0, size))
+               goto out;
+
+       p->last_op = IORING_OP_LAST - 1;
+       if (nr_args > IORING_OP_LAST)
+               nr_args = IORING_OP_LAST;
+
+       for (i = 0; i < nr_args; i++) {
+               p->ops[i].op = i;
+               if (!io_op_defs[i].not_supported)
+                       p->ops[i].flags = IO_URING_OP_SUPPORTED;
+       }
+       p->ops_len = i;
+
+       ret = 0;
+       if (copy_to_user(arg, p, size))
+               ret = -EFAULT;
+out:
+       kfree(p);
+       return ret;
+}
+
+static int io_register_personality(struct io_ring_ctx *ctx)
+{
+       const struct cred *creds = get_current_cred();
+       int id;
+
+       id = idr_alloc_cyclic(&ctx->personality_idr, (void *) creds, 1,
+                               USHRT_MAX, GFP_KERNEL);
+       if (id < 0)
+               put_cred(creds);
+       return id;
+}
+
+static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
+{
+       const struct cred *old_creds;
+
+       old_creds = idr_remove(&ctx->personality_idr, id);
+       if (old_creds) {
+               put_cred(old_creds);
+               return 0;
+       }
+
+       return -EINVAL;
+}
+
+static bool io_register_op_must_quiesce(int op)
+{
+       switch (op) {
+       case IORING_UNREGISTER_FILES:
+       case IORING_REGISTER_FILES_UPDATE:
+       case IORING_REGISTER_PROBE:
+       case IORING_REGISTER_PERSONALITY:
+       case IORING_UNREGISTER_PERSONALITY:
+               return false;
+       default:
+               return true;
+       }
+}
+
 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
                               void __user *arg, unsigned nr_args)
        __releases(ctx->uring_lock)
@@ -5445,18 +7062,26 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
        if (percpu_ref_is_dying(&ctx->refs))
                return -ENXIO;
 
-       percpu_ref_kill(&ctx->refs);
+       if (io_register_op_must_quiesce(opcode)) {
+               percpu_ref_kill(&ctx->refs);
 
-       /*
-        * Drop uring mutex before waiting for references to exit. If another
-        * thread is currently inside io_uring_enter() it might need to grab
-        * the uring_lock to make progress. If we hold it here across the drain
-        * wait, then we can deadlock. It's safe to drop the mutex here, since
-        * no new references will come in after we've killed the percpu ref.
-        */
-       mutex_unlock(&ctx->uring_lock);
-       wait_for_completion(&ctx->completions[0]);
-       mutex_lock(&ctx->uring_lock);
+               /*
+                * Drop uring mutex before waiting for references to exit. If
+                * another thread is currently inside io_uring_enter() it might
+                * need to grab the uring_lock to make progress. If we hold it
+                * here across the drain wait, then we can deadlock. It's safe
+                * to drop the mutex here, since no new references will come in
+                * after we've killed the percpu ref.
+                */
+               mutex_unlock(&ctx->uring_lock);
+               ret = wait_for_completion_interruptible(&ctx->completions[0]);
+               mutex_lock(&ctx->uring_lock);
+               if (ret) {
+                       percpu_ref_resurrect(&ctx->refs);
+                       ret = -EINTR;
+                       goto out;
+               }
+       }
 
        switch (opcode) {
        case IORING_REGISTER_BUFFERS:
@@ -5481,10 +7106,17 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
                ret = io_sqe_files_update(ctx, arg, nr_args);
                break;
        case IORING_REGISTER_EVENTFD:
+       case IORING_REGISTER_EVENTFD_ASYNC:
                ret = -EINVAL;
                if (nr_args != 1)
                        break;
                ret = io_eventfd_register(ctx, arg);
+               if (ret)
+                       break;
+               if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
+                       ctx->eventfd_async = 1;
+               else
+                       ctx->eventfd_async = 0;
                break;
        case IORING_UNREGISTER_EVENTFD:
                ret = -EINVAL;
@@ -5492,14 +7124,35 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
                        break;
                ret = io_eventfd_unregister(ctx);
                break;
+       case IORING_REGISTER_PROBE:
+               ret = -EINVAL;
+               if (!arg || nr_args > 256)
+                       break;
+               ret = io_probe(ctx, arg, nr_args);
+               break;
+       case IORING_REGISTER_PERSONALITY:
+               ret = -EINVAL;
+               if (arg || nr_args)
+                       break;
+               ret = io_register_personality(ctx);
+               break;
+       case IORING_UNREGISTER_PERSONALITY:
+               ret = -EINVAL;
+               if (arg)
+                       break;
+               ret = io_unregister_personality(ctx, nr_args);
+               break;
        default:
                ret = -EINVAL;
                break;
        }
 
-       /* bring the ctx back to life */
-       reinit_completion(&ctx->completions[0]);
-       percpu_ref_reinit(&ctx->refs);
+       if (io_register_op_must_quiesce(opcode)) {
+               /* bring the ctx back to life */
+               percpu_ref_reinit(&ctx->refs);
+out:
+               reinit_completion(&ctx->completions[0]);
+       }
        return ret;
 }
 
@@ -5532,6 +7185,40 @@ out_fput:
 
 static int __init io_uring_init(void)
 {
+#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
+       BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
+       BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
+} while (0)
+
+#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
+       __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
+       BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
+       BUILD_BUG_SQE_ELEM(0,  __u8,   opcode);
+       BUILD_BUG_SQE_ELEM(1,  __u8,   flags);
+       BUILD_BUG_SQE_ELEM(2,  __u16,  ioprio);
+       BUILD_BUG_SQE_ELEM(4,  __s32,  fd);
+       BUILD_BUG_SQE_ELEM(8,  __u64,  off);
+       BUILD_BUG_SQE_ELEM(8,  __u64,  addr2);
+       BUILD_BUG_SQE_ELEM(16, __u64,  addr);
+       BUILD_BUG_SQE_ELEM(24, __u32,  len);
+       BUILD_BUG_SQE_ELEM(28,     __kernel_rwf_t, rw_flags);
+       BUILD_BUG_SQE_ELEM(28, /* compat */   int, rw_flags);
+       BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  fsync_flags);
+       BUILD_BUG_SQE_ELEM(28, __u16,  poll_events);
+       BUILD_BUG_SQE_ELEM(28, __u32,  sync_range_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  msg_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  timeout_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  accept_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  cancel_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  open_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  statx_flags);
+       BUILD_BUG_SQE_ELEM(28, __u32,  fadvise_advice);
+       BUILD_BUG_SQE_ELEM(32, __u64,  user_data);
+       BUILD_BUG_SQE_ELEM(40, __u16,  buf_index);
+       BUILD_BUG_SQE_ELEM(42, __u16,  personality);
+
+       BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
        req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
        return 0;
 };