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

Pull third hunk of vfs changes from Al Viro:
 "This contains the ->direct_IO() changes from Omar + saner
  generic_write_checks() + dealing with fcntl()/{read,write}() races
  (mirroring O_APPEND/O_DIRECT into iocb->ki_flags and instead of
  repeatedly looking at ->f_flags, which can be changed by fcntl(2),
  check ->ki_flags - which cannot) + infrastructure bits for dhowells'
  d_inode annotations + Christophs switch of /dev/loop to
  vfs_iter_write()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (30 commits)
  block: loop: switch to VFS ITER_BVEC
  configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode
  VFS: Make pathwalk use d_is_reg() rather than S_ISREG()
  VFS: Fix up debugfs to use d_is_dir() in place of S_ISDIR()
  VFS: Combine inode checks with d_is_negative() and d_is_positive() in pathwalk
  NFS: Don't use d_inode as a variable name
  VFS: Impose ordering on accesses of d_inode and d_flags
  VFS: Add owner-filesystem positive/negative dentry checks
  nfs: generic_write_checks() shouldn't be done on swapout...
  ocfs2: use __generic_file_write_iter()
  mirror O_APPEND and O_DIRECT into iocb->ki_flags
  switch generic_write_checks() to iocb and iter
  ocfs2: move generic_write_checks() before the alignment checks
  ocfs2_file_write_iter: stop messing with ppos
  udf_file_write_iter: reorder and simplify
  fuse: ->direct_IO() doesn't need generic_write_checks()
  ext4_file_write_iter: move generic_write_checks() up
  xfs_file_aio_write_checks: switch to iocb/iov_iter
  generic_write_checks(): drop isblk argument
  blkdev_write_iter: expand generic_file_checks() call in there
  ...

2 files changed, 43 insertions, 103 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 8d2bc840c288..f906a250da6a 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -855,10 +855,9 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
                 ocfs2_inode_unlock(inode, 1);
         }
 
-        written = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev,
-                        iter, offset,
-                        ocfs2_direct_IO_get_blocks,
-                        ocfs2_dio_end_io, NULL, 0);
+        written = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
+                                       offset, ocfs2_direct_IO_get_blocks,
+                                       ocfs2_dio_end_io, NULL, 0);
         if (unlikely(written < 0)) {
                 loff_t i_size = i_size_read(inode);
 
@@ -946,9 +945,7 @@ out:
         return ret;
 }
 
-static ssize_t ocfs2_direct_IO(int rw,
-                               struct kiocb *iocb,
-                               struct iov_iter *iter,
+static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
                                loff_t offset)
 {
         struct file *file = iocb->ki_filp;
@@ -970,12 +967,11 @@ static ssize_t ocfs2_direct_IO(int rw,
         if (i_size_read(inode) <= offset && !full_coherency)
                 return 0;
 
-        if (rw == READ)
-                return __blockdev_direct_IO(rw, iocb, inode,
-                                    inode->i_sb->s_bdev,
-                                    iter, offset,
-                                    ocfs2_direct_IO_get_blocks,
-                                    ocfs2_dio_end_io, NULL, 0);
+        if (iov_iter_rw(iter) == READ)
+                return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
+                                            iter, offset,
+                                            ocfs2_direct_IO_get_blocks,
+                                            ocfs2_dio_end_io, NULL, 0);
         else
                 return ocfs2_direct_IO_write(iocb, iter, offset);
 }
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 8c48e989beba..913fc250d85a 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2106,7 +2106,7 @@ out:
 }
 
 static int ocfs2_prepare_inode_for_write(struct file *file,
-                                         loff_t *ppos,
+                                         loff_t pos,
                                          size_t count,
                                          int appending,
                                          int *direct_io,
@@ -2115,7 +2115,7 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
         int ret = 0, meta_level = 0;
         struct dentry *dentry = file->f_path.dentry;
         struct inode *inode = dentry->d_inode;
-        loff_t saved_pos = 0, end;
+        loff_t end;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
         int full_coherency = !(osb->s_mount_opt &
                 OCFS2_MOUNT_COHERENCY_BUFFERED);
@@ -2155,23 +2155,16 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
                         }
                 }
 
-                /* work on a copy of ppos until we're sure that we won't have
-                 * to recalculate it due to relocking. */
-                if (appending)
-                        saved_pos = i_size_read(inode);
-                else
-                        saved_pos = *ppos;
-
-                end = saved_pos + count;
+                end = pos + count;
 
-                ret = ocfs2_check_range_for_refcount(inode, saved_pos, count);
+                ret = ocfs2_check_range_for_refcount(inode, pos, count);
                 if (ret == 1) {
                         ocfs2_inode_unlock(inode, meta_level);
                         meta_level = -1;
 
                         ret = ocfs2_prepare_inode_for_refcount(inode,
                                                                file,
-                                                               saved_pos,
+                                                               pos,
                                                                count,
                                                                &meta_level);
                         if (has_refcount)
@@ -2227,7 +2220,7 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
                  * caller will have to retake some cluster
                  * locks and initiate the io as buffered.
                  */
-                ret = ocfs2_check_range_for_holes(inode, saved_pos, count);
+                ret = ocfs2_check_range_for_holes(inode, pos, count);
                 if (ret == 1) {
                         /*
                          * Fallback to old way if the feature bit is not set.
@@ -2242,12 +2235,9 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
                 break;
         }
 
-        if (appending)
-                *ppos = saved_pos;
-
 out_unlock:
         trace_ocfs2_prepare_inode_for_write(OCFS2_I(inode)->ip_blkno,
-                                            saved_pos, appending, count,
+                                            pos, appending, count,
                                             direct_io, has_refcount);
 
         if (meta_level >= 0)
@@ -2260,19 +2250,20 @@ out:
 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 direct_io, appending, rw_level, have_alloc_sem  = 0;
         int can_do_direct, has_refcount = 0;
         ssize_t written = 0;
-        size_t count = iov_iter_count(from);
-        loff_t old_size, *ppos = &iocb->ki_pos;
+        ssize_t ret;
+        size_t count = iov_iter_count(from), orig_count;
+        loff_t old_size;
         u32 old_clusters;
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file);
-        struct address_space *mapping = file->f_mapping;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
         int full_coherency = !(osb->s_mount_opt &
                                OCFS2_MOUNT_COHERENCY_BUFFERED);
         int unaligned_dio = 0;
+        int dropped_dio = 0;
 
         trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
@@ -2283,8 +2274,8 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
         if (count == 0)
                 return 0;
 
-        appending = file->f_flags & O_APPEND ? 1 : 0;
-        direct_io = file->f_flags & O_DIRECT ? 1 : 0;
+        appending = iocb->ki_flags & IOCB_APPEND ? 1 : 0;
+        direct_io = iocb->ki_flags & IOCB_DIRECT ? 1 : 0;
 
         mutex_lock(&inode->i_mutex);
 
@@ -2329,8 +2320,17 @@ relock:
                 ocfs2_inode_unlock(inode, 1);
         }
 
+        orig_count = iov_iter_count(from);
+        ret = generic_write_checks(iocb, from);
+        if (ret <= 0) {
+                if (ret)
+                        mlog_errno(ret);
+                goto out;
+        }
+        count = ret;
+
         can_do_direct = direct_io;
-        ret = ocfs2_prepare_inode_for_write(file, ppos, count, appending,
+        ret = ocfs2_prepare_inode_for_write(file, iocb->ki_pos, count, appending,
                                             &can_do_direct, &has_refcount);
         if (ret < 0) {
                 mlog_errno(ret);
@@ -2338,7 +2338,7 @@ relock:
         }
 
         if (direct_io && !is_sync_kiocb(iocb))
-                unaligned_dio = ocfs2_is_io_unaligned(inode, count, *ppos);
+                unaligned_dio = ocfs2_is_io_unaligned(inode, count, iocb->ki_pos);
 
         /*
          * We can't complete the direct I/O as requested, fall back to
@@ -2351,6 +2351,9 @@ relock:
                 rw_level = -1;
 
                 direct_io = 0;
+                iocb->ki_flags &= ~IOCB_DIRECT;
+                iov_iter_reexpand(from, orig_count);
+                dropped_dio = 1;
                 goto relock;
         }
 
@@ -2374,74 +2377,15 @@ relock:
         /* communicate with ocfs2_dio_end_io */
         ocfs2_iocb_set_rw_locked(iocb, rw_level);
 
-        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) {
-                loff_t endbyte;
-                ssize_t written_buffered;
-                written = generic_file_direct_write(iocb, from, *ppos);
-                if (written < 0 || written == count) {
-                        ret = written;
-                        goto out_dio;
-                }
-
-                /*
-                 * for completing the rest of the request.
-                 */
-                count -= written;
-                written_buffered = generic_perform_write(file, from, *ppos);
-                /*
-                 * If generic_file_buffered_write() returned a synchronous error
-                 * then we want to return the number of bytes which were
-                 * direct-written, or the error code if that was zero. Note
-                 * that this differs from normal direct-io semantics, which
-                 * will return -EFOO even if some bytes were written.
-                 */
-                if (written_buffered < 0) {
-                        ret = written_buffered;
-                        goto out_dio;
-                }
-
-                /* We need to ensure that the page cache pages are written to
-                 * disk and invalidated to preserve the expected O_DIRECT
-                 * semantics.
-                 */
-                endbyte = *ppos + written_buffered - 1;
-                ret = filemap_write_and_wait_range(file->f_mapping, *ppos,
-                                endbyte);
-                if (ret == 0) {
-                        iocb->ki_pos = *ppos + written_buffered;
-                        written += written_buffered;
-                        invalidate_mapping_pages(mapping,
-                                        *ppos >> PAGE_CACHE_SHIFT,
-                                        endbyte >> PAGE_CACHE_SHIFT);
-                } else {
-                        /*
-                         * We don't know how much we wrote, so just return
-                         * the number of bytes which were direct-written
-                         */
-                }
-        } else {
-                current->backing_dev_info = inode_to_bdi(inode);
-                written = generic_perform_write(file, from, *ppos);
-                if (likely(written >= 0))
-                        iocb->ki_pos = *ppos + written;
-                current->backing_dev_info = NULL;
-        }
-
-out_dio:
+        written = __generic_file_write_iter(iocb, from);
         /* buffered aio wouldn't have proper lock coverage today */
-        BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT));
+        BUG_ON(written == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT));
 
         if (unlikely(written <= 0))
                 goto no_sync;
 
-        if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) ||
-            ((file->f_flags & O_DIRECT) && !direct_io)) {
+        if (((file->f_flags & O_DSYNC) && !direct_io) ||
+            IS_SYNC(inode) || dropped_dio) {
                 ret = filemap_fdatawrite_range(file->f_mapping,
                                                iocb->ki_pos - written,
                                                iocb->ki_pos - 1);
@@ -2552,7 +2496,7 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
          * buffered reads protect themselves in ->readpage().  O_DIRECT reads
          * need locks to protect pending reads from racing with truncate.
          */
-        if (filp->f_flags & O_DIRECT) {
+        if (iocb->ki_flags & IOCB_DIRECT) {
                 have_alloc_sem = 1;
                 ocfs2_iocb_set_sem_locked(iocb);
 
@@ -2586,7 +2530,7 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
         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));
+        BUG_ON(ret == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT));
 
         /* see ocfs2_file_write_iter */
         if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) {