Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...

2 files changed, 27 insertions, 118 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index d310d12a9adc..4a231a166cf8 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -599,9 +599,8 @@ static int ocfs2_releasepage(struct page *page, gfp_t wait)
 
 static ssize_t ocfs2_direct_IO(int rw,
                                struct kiocb *iocb,
-                               const struct iovec *iov,
-                               loff_t offset,
-                               unsigned long nr_segs)
+                               struct iov_iter *iter,
+                               loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file)->i_mapping->host;
@@ -618,7 +617,7 @@ static ssize_t ocfs2_direct_IO(int rw,
                 return 0;
 
         return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
-                                    iov, offset, nr_segs,
+                                    iter, offset,
                                     ocfs2_direct_IO_get_blocks,
                                     ocfs2_dio_end_io, NULL, 0);
 }
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 8eb6e5732d3b..2930e231f3f9 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2233,16 +2233,13 @@ out:
         return ret;
 }
 
-static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
-                                    const struct iovec *iov,
-                                    unsigned long nr_segs,
-                                    loff_t pos)
+static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
+                                    struct iov_iter *from)
 {
         int ret, direct_io, appending, rw_level, have_alloc_sem  = 0;
         int can_do_direct, has_refcount = 0;
         ssize_t written = 0;
-        size_t ocount;          /* original count */
-        size_t count;           /* after file limit checks */
+        size_t count = iov_iter_count(from);
         loff_t old_size, *ppos = &iocb->ki_pos;
         u32 old_clusters;
         struct file *file = iocb->ki_filp;
@@ -2256,7 +2253,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
                 file->f_path.dentry->d_name.len,
                 file->f_path.dentry->d_name.name,
-                (unsigned int)nr_segs);
+                (unsigned int)from->nr_segs);   /* GRRRRR */
 
         if (iocb->ki_nbytes == 0)
                 return 0;
@@ -2354,29 +2351,21 @@ relock:
         /* communicate with ocfs2_dio_end_io */
         ocfs2_iocb_set_rw_locked(iocb, rw_level);
 
-        ret = generic_segment_checks(iov, &nr_segs, &ocount,
-                                     VERIFY_READ);
-        if (ret)
-                goto out_dio;
-
-        count = ocount;
         ret = generic_write_checks(file, ppos, &count,
                                    S_ISBLK(inode->i_mode));
         if (ret)
                 goto out_dio;
 
+        iov_iter_truncate(from, count);
         if (direct_io) {
-                written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
-                                                    count, ocount);
+                written = generic_file_direct_write(iocb, from, *ppos);
                 if (written < 0) {
                         ret = written;
                         goto out_dio;
                 }
         } else {
-                struct iov_iter from;
-                iov_iter_init(&from, iov, nr_segs, count, 0);
                 current->backing_dev_info = file->f_mapping->backing_dev_info;
-                written = generic_perform_write(file, &from, *ppos);
+                written = generic_perform_write(file, from, *ppos);
                 if (likely(written >= 0))
                         iocb->ki_pos = *ppos + written;
                 current->backing_dev_info = NULL;
@@ -2441,84 +2430,6 @@ out_sems:
         return ret;
 }
 
-static int ocfs2_splice_to_file(struct pipe_inode_info *pipe,
-                                struct file *out,
-                                struct splice_desc *sd)
-{
-        int ret;
-
-        ret = ocfs2_prepare_inode_for_write(out, &sd->pos,
-                                            sd->total_len, 0, NULL, NULL);
-        if (ret < 0) {
-                mlog_errno(ret);
-                return ret;
-        }
-
-        return splice_from_pipe_feed(pipe, sd, pipe_to_file);
-}
-
-static ssize_t ocfs2_file_splice_write(struct pipe_inode_info *pipe,
-                                       struct file *out,
-                                       loff_t *ppos,
-                                       size_t len,
-                                       unsigned int flags)
-{
-        int ret;
-        struct address_space *mapping = out->f_mapping;
-        struct inode *inode = mapping->host;
-        struct splice_desc sd = {
-                .total_len = len,
-                .flags = flags,
-                .pos = *ppos,
-                .u.file = out,
-        };
-
-
-        trace_ocfs2_file_splice_write(inode, out, out->f_path.dentry,
-                        (unsigned long long)OCFS2_I(inode)->ip_blkno,
-                        out->f_path.dentry->d_name.len,
-                        out->f_path.dentry->d_name.name, len);
-
-        pipe_lock(pipe);
-
-        splice_from_pipe_begin(&sd);
-        do {
-                ret = splice_from_pipe_next(pipe, &sd);
-                if (ret <= 0)
-                        break;
-
-                mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
-                ret = ocfs2_rw_lock(inode, 1);
-                if (ret < 0)
-                        mlog_errno(ret);
-                else {
-                        ret = ocfs2_splice_to_file(pipe, out, &sd);
-                        ocfs2_rw_unlock(inode, 1);
-                }
-                mutex_unlock(&inode->i_mutex);
-        } while (ret > 0);
-        splice_from_pipe_end(pipe, &sd);
-
-        pipe_unlock(pipe);
-
-        if (sd.num_spliced)
-                ret = sd.num_spliced;
-
-        if (ret > 0) {
-                int err;
-
-                err = generic_write_sync(out, *ppos, ret);
-                if (err)
-                        ret = err;
-                else
-                        *ppos += ret;
-
-                balance_dirty_pages_ratelimited(mapping);
-        }
-
-        return ret;
-}
-
 static ssize_t ocfs2_file_splice_read(struct file *in,
                                       loff_t *ppos,
                                       struct pipe_inode_info *pipe,
@@ -2534,7 +2445,7 @@ static ssize_t ocfs2_file_splice_read(struct file *in,
                         in->f_path.dentry->d_name.name, len);
 
         /*
-         * See the comment in ocfs2_file_aio_read()
+         * See the comment in ocfs2_file_read_iter()
          */
         ret = ocfs2_inode_lock_atime(inode, in->f_path.mnt, &lock_level);
         if (ret < 0) {
@@ -2549,10 +2460,8 @@ bail:
         return ret;
 }
 
-static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
-                                   const struct iovec *iov,
-                                   unsigned long nr_segs,
-                                   loff_t pos)
+static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
+                                   struct iov_iter *to)
 {
         int ret = 0, rw_level = -1, have_alloc_sem = 0, lock_level = 0;
         struct file *filp = iocb->ki_filp;
@@ -2561,7 +2470,8 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
         trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry,
                         (unsigned long long)OCFS2_I(inode)->ip_blkno,
                         filp->f_path.dentry->d_name.len,
-                        filp->f_path.dentry->d_name.name, nr_segs);
+                        filp->f_path.dentry->d_name.name,
+                        to->nr_segs);   /* GRRRRR */
 
 
         if (!inode) {
@@ -2606,13 +2516,13 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
         }
         ocfs2_inode_unlock(inode, lock_level);
 
-        ret = generic_file_aio_read(iocb, iov, nr_segs, iocb->ki_pos);
+        ret = generic_file_read_iter(iocb, to);
         trace_generic_file_aio_read_ret(ret);
 
         /* buffered aio wouldn't have proper lock coverage today */
         BUG_ON(ret == -EIOCBQUEUED && !(filp->f_flags & O_DIRECT));
 
-        /* see ocfs2_file_aio_write */
+        /* see ocfs2_file_write_iter */
         if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) {
                 rw_level = -1;
                 have_alloc_sem = 0;
@@ -2705,14 +2615,14 @@ const struct inode_operations ocfs2_special_file_iops = {
  */
 const struct file_operations ocfs2_fops = {
         .llseek         = ocfs2_file_llseek,
-        .read           = do_sync_read,
-        .write          = do_sync_write,
+        .read           = new_sync_read,
+        .write          = new_sync_write,
         .mmap           = ocfs2_mmap,
         .fsync          = ocfs2_sync_file,
         .release        = ocfs2_file_release,
         .open           = ocfs2_file_open,
-        .aio_read       = ocfs2_file_aio_read,
-        .aio_write      = ocfs2_file_aio_write,
+        .read_iter      = ocfs2_file_read_iter,
+        .write_iter     = ocfs2_file_write_iter,
         .unlocked_ioctl = ocfs2_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = ocfs2_compat_ioctl,
@@ -2720,7 +2630,7 @@ const struct file_operations ocfs2_fops = {
         .lock           = ocfs2_lock,
         .flock          = ocfs2_flock,
         .splice_read    = ocfs2_file_splice_read,
-        .splice_write   = ocfs2_file_splice_write,
+        .splice_write   = iter_file_splice_write,
         .fallocate      = ocfs2_fallocate,
 };
 
@@ -2753,21 +2663,21 @@ const struct file_operations ocfs2_dops = {
  */
 const struct file_operations ocfs2_fops_no_plocks = {
         .llseek         = ocfs2_file_llseek,
-        .read           = do_sync_read,
-        .write          = do_sync_write,
+        .read           = new_sync_read,
+        .write          = new_sync_write,
         .mmap           = ocfs2_mmap,
         .fsync          = ocfs2_sync_file,
         .release        = ocfs2_file_release,
         .open           = ocfs2_file_open,
-        .aio_read       = ocfs2_file_aio_read,
-        .aio_write      = ocfs2_file_aio_write,
+        .read_iter      = ocfs2_file_read_iter,
+        .write_iter     = ocfs2_file_write_iter,
         .unlocked_ioctl = ocfs2_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = ocfs2_compat_ioctl,
 #endif
         .flock          = ocfs2_flock,
         .splice_read    = ocfs2_file_splice_read,
-        .splice_write   = ocfs2_file_splice_write,
+        .splice_write   = iter_file_splice_write,
         .fallocate      = ocfs2_fallocate,
 };