Merge branch 'master'

14 files changed, 208 insertions, 91 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 2524629dc835..f9b5842c8d2d 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -842,6 +842,12 @@ config TMPFS
 config HUGETLBFS
         bool "HugeTLB file system support"
         depends X86 || IA64 || PPC64 || SPARC64 || SUPERH || BROKEN
+        help
+          hugetlbfs is a filesystem backing for HugeTLB pages, based on
+          ramfs. For architectures that support it, say Y here and read
+          <file:Documentation/vm/hugetlbpage.txt> for details.
+
+          If unsure, say N.
 
 config HUGETLB_PAGE
         def_bool HUGETLBFS
diff --git a/fs/exec.c b/fs/exec.c
index 4121bb559739..3a79d97ac234 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -712,7 +712,7 @@ static int de_thread(struct task_struct *tsk)
                 attach_pid(current, PIDTYPE_PID,  current->pid);
                 attach_pid(current, PIDTYPE_PGID, current->signal->pgrp);
                 attach_pid(current, PIDTYPE_SID,  current->signal->session);
-                list_add_tail(&current->tasks, &init_task.tasks);
+                list_add_tail_rcu(&current->tasks, &init_task.tasks);
 
                 current->group_leader = current;
                 leader->group_leader = current;
diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c
index 14f5f6ea3e72..c5ffa8523968 100644
--- a/fs/ext3/resize.c
+++ b/fs/ext3/resize.c
@@ -767,6 +767,7 @@ int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input)
         if (input->group != sbi->s_groups_count) {
                 ext3_warning(sb, __FUNCTION__,
                              "multiple resizers run on filesystem!");
+                unlock_super(sb);
                 err = -EBUSY;
                 goto exit_journal;
         }
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index d2b66bad7d50..3ef739120dff 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -650,7 +650,7 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
         svc_wake_up(block->b_daemon);
 }
 
-void nlmsvc_grant_release(void *data)
+static void nlmsvc_grant_release(void *data)
 {
         struct nlm_rqst         *call = data;
 
diff --git a/fs/locks.c b/fs/locks.c
index dda83d6cd48b..efad798824dc 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2230,7 +2230,12 @@ void steal_locks(fl_owner_t from)
 
         lock_kernel();
         j = 0;
-        rcu_read_lock();
+
+        /*
+         * We are not taking a ref to the file structures, so
+         * we need to acquire ->file_lock.
+         */
+        spin_lock(&files->file_lock);
         fdt = files_fdtable(files);
         for (;;) {
                 unsigned long set;
@@ -2248,7 +2253,7 @@ void steal_locks(fl_owner_t from)
                         set >>= 1;
                 }
         }
-        rcu_read_unlock();
+        spin_unlock(&files->file_lock);
         unlock_kernel();
 }
 EXPORT_SYMBOL(steal_locks);
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index a23f34894167..cae74dd4c7f5 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -128,15 +128,14 @@ struct inode_operations nfs4_dir_inode_operations = {
 static int
 nfs_opendir(struct inode *inode, struct file *filp)
 {
-        int res = 0;
+        int res;
 
         dfprintk(VFS, "NFS: opendir(%s/%ld)\n",
                         inode->i_sb->s_id, inode->i_ino);
 
         lock_kernel();
         /* Call generic open code in order to cache credentials */
-        if (!res)
-                res = nfs_open(inode, filp);
+        res = nfs_open(inode, filp);
         unlock_kernel();
         return res;
 }
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 0f583cb16ddb..3c72b0c07283 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -112,10 +112,9 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
  */
 ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs)
 {
-        struct dentry *dentry = iocb->ki_filp->f_dentry;
-
         dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n",
-                        dentry->d_name.name, (long long) pos, nr_segs);
+                        iocb->ki_filp->f_dentry->d_name.name,
+                        (long long) pos, nr_segs);
 
         return -EINVAL;
 }
@@ -468,7 +467,6 @@ static const struct rpc_call_ops nfs_commit_direct_ops = {
 static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
 {
         struct nfs_write_data *data = dreq->commit_data;
-        struct rpc_task *task = &data->task;
 
         data->inode = dreq->inode;
         data->cred = dreq->ctx->cred;
@@ -489,7 +487,7 @@ static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
         /* Note: task.tk_ops->rpc_release will free dreq->commit_data */
         dreq->commit_data = NULL;
 
-        dprintk("NFS: %5u initiated commit call\n", task->tk_pid);
+        dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
 
         lock_kernel();
         rpc_execute(&data->task);
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index f1df2c8d9259..fade02c15e6e 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -534,10 +534,9 @@ static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
  */
 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
 {
-        struct inode * inode = filp->f_mapping->host;
-
         dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n",
-                        inode->i_sb->s_id, inode->i_ino,
+                        filp->f_dentry->d_inode->i_sb->s_id,
+                        filp->f_dentry->d_inode->i_ino,
                         fl->fl_type, fl->fl_flags);
 
         /*
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 2f7656b911b6..d0b991a92327 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -700,12 +700,9 @@ static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
         /*
          * Display superblock I/O counters
          */
-        for (cpu = 0; cpu < NR_CPUS; cpu++) {
+        for_each_possible_cpu(cpu) {
                 struct nfs_iostats *stats;
 
-                if (!cpu_possible(cpu))
-                        continue;
-
                 preempt_disable();
                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 47ece1dd3c67..d86c0db7b1e8 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1218,7 +1218,7 @@ out:
         return status;
 }
 
-static void nfs4_intent_set_file(struct nameidata *nd, struct dentry *dentry, struct nfs4_state *state)
+static int nfs4_intent_set_file(struct nameidata *nd, struct dentry *dentry, struct nfs4_state *state)
 {
         struct file *filp;
 
@@ -1227,8 +1227,10 @@ static void nfs4_intent_set_file(struct nameidata *nd, struct dentry *dentry, st
                 struct nfs_open_context *ctx;
                 ctx = (struct nfs_open_context *)filp->private_data;
                 ctx->state = state;
-        } else
-                nfs4_close_state(state, nd->intent.open.flags);
+                return 0;
+        }
+        nfs4_close_state(state, nd->intent.open.flags);
+        return PTR_ERR(filp);
 }
 
 struct dentry *
@@ -1835,7 +1837,7 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                         nfs_setattr_update_inode(state->inode, sattr);
         }
         if (status == 0 && nd != NULL && (nd->flags & LOOKUP_OPEN))
-                nfs4_intent_set_file(nd, dentry, state);
+                status = nfs4_intent_set_file(nd, dentry, state);
         else
                 nfs4_close_state(state, flags);
 out:
diff --git a/fs/open.c b/fs/open.c
index c32c89d6d8db..53ec28c36777 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -331,7 +331,10 @@ out:
 
 asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
 {
-        return do_sys_ftruncate(fd, length, 1);
+        long ret = do_sys_ftruncate(fd, length, 1);
+        /* avoid REGPARM breakage on x86: */
+        prevent_tail_call(ret);
+        return ret;
 }
 
 /* LFS versions of truncate are only needed on 32 bit machines */
@@ -343,7 +346,10 @@ asmlinkage long sys_truncate64(const char __user * path, loff_t length)
 
 asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
 {
-        return do_sys_ftruncate(fd, length, 0);
+        long ret = do_sys_ftruncate(fd, length, 0);
+        /* avoid REGPARM breakage on x86: */
+        prevent_tail_call(ret);
+        return ret;
 }
 #endif
 
@@ -1093,20 +1099,30 @@ long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
 
 asmlinkage long sys_open(const char __user *filename, int flags, int mode)
 {
+        long ret;
+
         if (force_o_largefile())
                 flags |= O_LARGEFILE;
 
-        return do_sys_open(AT_FDCWD, filename, flags, mode);
+        ret = do_sys_open(AT_FDCWD, filename, flags, mode);
+        /* avoid REGPARM breakage on x86: */
+        prevent_tail_call(ret);
+        return ret;
 }
 EXPORT_SYMBOL_GPL(sys_open);
 
 asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
                            int mode)
 {
+        long ret;
+
         if (force_o_largefile())
                 flags |= O_LARGEFILE;
 
-        return do_sys_open(dfd, filename, flags, mode);
+        ret = do_sys_open(dfd, filename, flags, mode);
+        /* avoid REGPARM breakage on x86: */
+        prevent_tail_call(ret);
+        return ret;
 }
 EXPORT_SYMBOL_GPL(sys_openat);
 
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index f3b6af071722..45ae7dd3c650 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -372,6 +372,7 @@ static char *make_block_name(struct gendisk *disk)
         char *name;
         static char *block_str = "block:";
         int size;
+        char *s;
 
         size = strlen(block_str) + strlen(disk->disk_name) + 1;
         name = kmalloc(size, GFP_KERNEL);
@@ -379,6 +380,10 @@ static char *make_block_name(struct gendisk *disk)
                 return NULL;
         strcpy(name, block_str);
         strcat(name, disk->disk_name);
+        /* ewww... some of these buggers have / in name... */
+        s = strchr(name, '/');
+        if (s)
+                *s = '!';
         return name;
 }
 
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a3a3eecef689..6cc77dc3f3ff 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -297,16 +297,20 @@ static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsm
 
         files = get_files_struct(task);
         if (files) {
-                rcu_read_lock();
+                /*
+                 * We are not taking a ref to the file structure, so we must
+                 * hold ->file_lock.
+                 */
+                spin_lock(&files->file_lock);
                 file = fcheck_files(files, fd);
                 if (file) {
                         *mnt = mntget(file->f_vfsmnt);
                         *dentry = dget(file->f_dentry);
-                        rcu_read_unlock();
+                        spin_unlock(&files->file_lock);
                         put_files_struct(files);
                         return 0;
                 }
-                rcu_read_unlock();
+                spin_unlock(&files->file_lock);
                 put_files_struct(files);
         }
         return -ENOENT;
@@ -1523,7 +1527,12 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
         if (!files)
                 goto out_unlock;
         inode->i_mode = S_IFLNK;
-        rcu_read_lock();
+
+        /*
+         * We are not taking a ref to the file structure, so we must
+         * hold ->file_lock.
+         */
+        spin_lock(&files->file_lock);
         file = fcheck_files(files, fd);
         if (!file)
                 goto out_unlock2;
@@ -1531,7 +1540,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
                 inode->i_mode |= S_IRUSR | S_IXUSR;
         if (file->f_mode & 2)
                 inode->i_mode |= S_IWUSR | S_IXUSR;
-        rcu_read_unlock();
+        spin_unlock(&files->file_lock);
         put_files_struct(files);
         inode->i_op = &proc_pid_link_inode_operations;
         inode->i_size = 64;
@@ -1541,7 +1550,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
         return NULL;
 
 out_unlock2:
-        rcu_read_unlock();
+        spin_unlock(&files->file_lock);
         put_files_struct(files);
 out_unlock:
         iput(inode);
diff --git a/fs/splice.c b/fs/splice.c
index 8d57e89924a6..0559e7577a04 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -50,7 +50,8 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
         struct page *page = buf->page;
         struct address_space *mapping = page_mapping(page);
 
-        WARN_ON(!PageLocked(page));
+        lock_page(page);
+
         WARN_ON(!PageUptodate(page));
 
         /*
@@ -65,8 +66,10 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
         if (PagePrivate(page))
                 try_to_release_page(page, mapping_gfp_mask(mapping));
 
-        if (!remove_mapping(mapping, page))
+        if (!remove_mapping(mapping, page)) {
+                unlock_page(page);
                 return 1;
+        }
 
         buf->flags |= PIPE_BUF_FLAG_STOLEN | PIPE_BUF_FLAG_LRU;
         return 0;
@@ -145,8 +148,8 @@ static struct pipe_buf_operations page_cache_pipe_buf_ops = {
  * pipe buffer operations. Otherwise very similar to the regular pipe_writev().
  */
 static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages,
-                            int nr_pages, unsigned long offset,
-                            unsigned long len, unsigned int flags)
+                            int nr_pages, unsigned long len,
+                            unsigned int offset, unsigned int flags)
 {
         int ret, do_wakeup, i;
 
@@ -243,14 +246,16 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                            unsigned int flags)
 {
         struct address_space *mapping = in->f_mapping;
-        unsigned int offset, nr_pages;
+        unsigned int loff, offset, nr_pages;
         struct page *pages[PIPE_BUFFERS];
         struct page *page;
-        pgoff_t index;
+        pgoff_t index, end_index;
+        loff_t isize;
+        size_t bytes;
         int i, error;
 
         index = *ppos >> PAGE_CACHE_SHIFT;
-        offset = *ppos & ~PAGE_CACHE_MASK;
+        loff = offset = *ppos & ~PAGE_CACHE_MASK;
         nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
         if (nr_pages > PIPE_BUFFERS)
@@ -268,7 +273,17 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
          * Now fill in the holes:
          */
         error = 0;
+        bytes = 0;
         for (i = 0; i < nr_pages; i++, index++) {
+                unsigned int this_len;
+
+                if (!len)
+                        break;
+
+                /*
+                 * this_len is the max we'll use from this page
+                 */
+                this_len = min(len, PAGE_CACHE_SIZE - loff);
 find_page:
                 /*
                  * lookup the page for this index
@@ -276,14 +291,6 @@ find_page:
                 page = find_get_page(mapping, index);
                 if (!page) {
                         /*
-                         * If in nonblock mode then dont block on
-                         * readpage (we've kicked readahead so there
-                         * will be asynchronous progress):
-                         */
-                        if (flags & SPLICE_F_NONBLOCK)
-                                break;
-
-                        /*
                          * page didn't exist, allocate one
                          */
                         page = page_cache_alloc_cold(mapping);
@@ -304,6 +311,13 @@ find_page:
                  * If the page isn't uptodate, we may need to start io on it
                  */
                 if (!PageUptodate(page)) {
+                        /*
+                         * If in nonblock mode then dont block on waiting
+                         * for an in-flight io page
+                         */
+                        if (flags & SPLICE_F_NONBLOCK)
+                                break;
+
                         lock_page(page);
 
                         /*
@@ -336,13 +350,43 @@ readpage:
                                         goto find_page;
                                 break;
                         }
+
+                        /*
+                         * i_size must be checked after ->readpage().
+                         */
+                        isize = i_size_read(mapping->host);
+                        end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+                        if (unlikely(!isize || index > end_index)) {
+                                page_cache_release(page);
+                                break;
+                        }
+
+                        /*
+                         * if this is the last page, see if we need to shrink
+                         * the length and stop
+                         */
+                        if (end_index == index) {
+                                loff = PAGE_CACHE_SIZE - (isize & ~PAGE_CACHE_MASK);
+                                if (bytes + loff > isize) {
+                                        page_cache_release(page);
+                                        break;
+                                }
+                                /*
+                                 * force quit after adding this page
+                                 */
+                                nr_pages = i;
+                                this_len = min(this_len, loff);
+                        }
                 }
 fill_it:
                 pages[i] = page;
+                bytes += this_len;
+                len -= this_len;
+                loff = 0;
         }
 
         if (i)
-                return move_to_pipe(pipe, pages, i, offset, len, flags);
+                return move_to_pipe(pipe, pages, i, bytes, offset, flags);
 
         return error;
 }
@@ -369,17 +413,20 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
         while (len) {
                 ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
 
-                if (ret <= 0)
+                if (ret < 0)
                         break;
+                else if (!ret) {
+                        if (spliced)
+                                break;
+                        if (flags & SPLICE_F_NONBLOCK) {
+                                ret = -EAGAIN;
+                                break;
+                        }
+                }
 
                 *ppos += ret;
                 len -= ret;
                 spliced += ret;
-
-                if (!(flags & SPLICE_F_NONBLOCK))
-                        continue;
-                ret = -EAGAIN;
-                break;
         }
 
         if (spliced)
@@ -474,14 +521,12 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
         if (sd->flags & SPLICE_F_MOVE) {
                 /*
                  * If steal succeeds, buf->page is now pruned from the vm
-                 * side (LRU and page cache) and we can reuse it.
+                 * side (LRU and page cache) and we can reuse it. The page
+                 * will also be looked on successful return.
                  */
                 if (buf->ops->steal(info, buf))
                         goto find_page;
 
-                /*
-                 * this will also set the page locked
-                 */
                 page = buf->page;
                 if (add_to_page_cache(page, mapping, index, gfp_mask))
                         goto find_page;
@@ -490,15 +535,27 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
                         lru_cache_add(page);
         } else {
 find_page:
-                ret = -ENOMEM;
-                page = find_or_create_page(mapping, index, gfp_mask);
-                if (!page)
-                        goto out_nomem;
+                page = find_lock_page(mapping, index);
+                if (!page) {
+                        ret = -ENOMEM;
+                        page = page_cache_alloc_cold(mapping);
+                        if (unlikely(!page))
+                                goto out_nomem;
+
+                        /*
+                         * This will also lock the page
+                         */
+                        ret = add_to_page_cache_lru(page, mapping, index,
+                                                    gfp_mask);
+                        if (unlikely(ret))
+                                goto out;
+                }
 
                 /*
-                 * If the page is uptodate, it is also locked. If it isn't
-                 * uptodate, we can mark it uptodate if we are filling the
-                 * full page. Otherwise we need to read it in first...
+                 * We get here with the page locked. If the page is also
+                 * uptodate, we don't need to do more. If it isn't, we
+                 * may need to bring it in if we are not going to overwrite
+                 * the full page.
                  */
                 if (!PageUptodate(page)) {
                         if (sd->len < PAGE_CACHE_SIZE) {
@@ -520,10 +577,8 @@ find_page:
                                         ret = -EIO;
                                         goto out;
                                 }
-                        } else {
-                                WARN_ON(!PageLocked(page));
+                        } else
                                 SetPageUptodate(page);
-                        }
                 }
         }
 
@@ -552,10 +607,10 @@ find_page:
         mark_page_accessed(page);
         balance_dirty_pages_ratelimited(mapping);
 out:
-        if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) {
+        if (!(buf->flags & PIPE_BUF_FLAG_STOLEN))
                 page_cache_release(page);
-                unlock_page(page);
-        }
+
+        unlock_page(page);
 out_nomem:
         buf->ops->unmap(info, buf);
         return ret;
@@ -687,22 +742,26 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
         ssize_t ret;
 
         ret = move_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
-
-        /*
-         * If file or inode is SYNC and we actually wrote some data, sync it.
-         */
-        if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(mapping->host))
-            && ret > 0) {
+        if (ret > 0) {
                 struct inode *inode = mapping->host;
-                int err;
 
-                mutex_lock(&inode->i_mutex);
-                err = generic_osync_inode(mapping->host, mapping,
-                                          OSYNC_METADATA|OSYNC_DATA);
-                mutex_unlock(&inode->i_mutex);
+                *ppos += ret;
+
+                /*
+                 * If file or inode is SYNC and we actually wrote some data,
+                 * sync it.
+                 */
+                if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) {
+                        int err;
+
+                        mutex_lock(&inode->i_mutex);
+                        err = generic_osync_inode(inode, mapping,
+                                                  OSYNC_METADATA|OSYNC_DATA);
+                        mutex_unlock(&inode->i_mutex);
 
-                if (err)
-                        ret = err;
+                        if (err)
+                                ret = err;
+                }
         }
 
         return ret;
@@ -904,6 +963,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
 {
         struct pipe_inode_info *pipe;
         loff_t offset, *off;
+        long ret;
 
         pipe = in->f_dentry->d_inode->i_pipe;
         if (pipe) {
@@ -918,7 +978,12 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                 } else
                         off = &out->f_pos;
 
-                return do_splice_from(pipe, out, off, len, flags);
+                ret = do_splice_from(pipe, out, off, len, flags);
+
+                if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
+                        ret = -EFAULT;
+
+                return ret;
         }
 
         pipe = out->f_dentry->d_inode->i_pipe;
@@ -934,7 +999,12 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                 } else
                         off = &in->f_pos;
 
-                return do_splice_to(in, off, pipe, len, flags);
+                ret = do_splice_to(in, off, pipe, len, flags);
+
+                if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
+                        ret = -EFAULT;
+
+                return ret;
         }
 
         return -EINVAL;
@@ -979,7 +1049,9 @@ static int link_pipe(struct pipe_inode_info *ipipe,
                      size_t len, unsigned int flags)
 {
         struct pipe_buffer *ibuf, *obuf;
-        int ret = 0, do_wakeup = 0, i;
+        int ret, do_wakeup, i, ipipe_first;
+
+        ret = do_wakeup = ipipe_first = 0;
 
         /*
          * Potential ABBA deadlock, work around it by ordering lock
@@ -987,6 +1059,7 @@ static int link_pipe(struct pipe_inode_info *ipipe,
          * could deadlock (one doing tee from A -> B, the other from B -> A).
          */
         if (ipipe->inode < opipe->inode) {
+                ipipe_first = 1;
                 mutex_lock(&ipipe->inode->i_mutex);
                 mutex_lock(&opipe->inode->i_mutex);
         } else {
@@ -1035,9 +1108,11 @@ static int link_pipe(struct pipe_inode_info *ipipe,
 
                         /*
                          * We have input available, but no output room.
-                         * If we already copied data, return that.
+                         * If we already copied data, return that. If we
+                         * need to drop the opipe lock, it must be ordered
+                         * last to avoid deadlocks.
                          */
-                        if (flags & SPLICE_F_NONBLOCK) {
+                        if ((flags & SPLICE_F_NONBLOCK) || !ipipe_first) {
                                 if (!ret)
                                         ret = -EAGAIN;
                                 break;
@@ -1071,7 +1146,12 @@ static int link_pipe(struct pipe_inode_info *ipipe,
                         if (ret)
                                 break;
                 }
-                if (flags & SPLICE_F_NONBLOCK) {
+                /*
+                 * pipe_wait() drops the ipipe mutex. To avoid deadlocks
+                 * with another process, we can only safely do that if
+                 * the ipipe lock is ordered last.
+                 */
+                if ((flags & SPLICE_F_NONBLOCK) || ipipe_first) {
                         if (!ret)
                                 ret = -EAGAIN;
                         break;