Merge tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfs

Pull xfs update from Dave Chinner:
 "There are a couple of new fallocate features in this request - it was
  decided that it was easiest to push them through the XFS tree using
  topic branches and have the ext4 support be based on those branches.
  Hence you may see some overlap with the ext4 tree merge depending on
  how they including those topic branches into their tree.  Other than
  that, there is O_TMPFILE support, some cleanups and bug fixes.

  The main changes in the XFS tree for 3.15-rc1 are:

   - O_TMPFILE support
   - allowing AIO+DIO writes beyond EOF
   - FALLOC_FL_COLLAPSE_RANGE support for fallocate syscall and XFS
     implementation
   - FALLOC_FL_ZERO_RANGE support for fallocate syscall and XFS
     implementation
   - IO verifier cleanup and rework
   - stack usage reduction changes
   - vm_map_ram NOIO context fixes to remove lockdep warings
   - various bug fixes and cleanups"

* tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfs: (34 commits)
  xfs: fix directory hash ordering bug
  xfs: extra semi-colon breaks a condition
  xfs: Add support for FALLOC_FL_ZERO_RANGE
  fs: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
  xfs: inode log reservations are still too small
  xfs: xfs_check_page_type buffer checks need help
  xfs: avoid AGI/AGF deadlock scenario for inode chunk allocation
  xfs: use NOIO contexts for vm_map_ram
  xfs: don't leak EFSBADCRC to userspace
  xfs: fix directory inode iolock lockdep false positive
  xfs: allocate xfs_da_args to reduce stack footprint
  xfs: always do log forces via the workqueue
  xfs: modify verifiers to differentiate CRC from other errors
  xfs: print useful caller information in xfs_error_report
  xfs: add xfs_verifier_error()
  xfs: add helper for updating checksums on xfs_bufs
  xfs: add helper for verifying checksums on xfs_bufs
  xfs: Use defines for CRC offsets in all cases
  xfs: skip pointless CRC updates after verifier failures
  xfs: Add support FALLOC_FL_COLLAPSE_RANGE for fallocate
  ...

1 files changed, 52 insertions, 32 deletions

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index db2cfb067d0b..75df77d09f75 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -632,38 +632,46 @@ xfs_map_at_offset(
 }
 
 /*
- * Test if a given page is suitable for writing as part of an unwritten
- * or delayed allocate extent.
+ * Test if a given page contains at least one buffer of a given @type.
+ * If @check_all_buffers is true, then we walk all the buffers in the page to
+ * try to find one of the type passed in. If it is not set, then the caller only
+ * needs to check the first buffer on the page for a match.
  */
-STATIC int
+STATIC bool
 xfs_check_page_type(
 	struct page		*page,
-	unsigned int		type)
+	unsigned int		type,
+	bool			check_all_buffers)
 {
-	if (PageWriteback(page))
-		return 0;
+	struct buffer_head	*bh;
+	struct buffer_head	*head;
 
-	if (page->mapping && page_has_buffers(page)) {
-		struct buffer_head	*bh, *head;
-		int			acceptable = 0;
+	if (PageWriteback(page))
+		return false;
+	if (!page->mapping)
+		return false;
+	if (!page_has_buffers(page))
+		return false;
 
-		bh = head = page_buffers(page);
-		do {
-			if (buffer_unwritten(bh))
-				acceptable += (type == XFS_IO_UNWRITTEN);
-			else if (buffer_delay(bh))
-				acceptable += (type == XFS_IO_DELALLOC);
-			else if (buffer_dirty(bh) && buffer_mapped(bh))
-				acceptable += (type == XFS_IO_OVERWRITE);
-			else
-				break;
-		} while ((bh = bh->b_this_page) != head);
+	bh = head = page_buffers(page);
+	do {
+		if (buffer_unwritten(bh)) {
+			if (type == XFS_IO_UNWRITTEN)
+				return true;
+		} else if (buffer_delay(bh)) {
+			if (type == XFS_IO_DELALLOC)
+				return true;
+		} else if (buffer_dirty(bh) && buffer_mapped(bh)) {
+			if (type == XFS_IO_OVERWRITE)
+				return true;
+		}
 
-		if (acceptable)
-			return 1;
-	}
+		/* If we are only checking the first buffer, we are done now. */
+		if (!check_all_buffers)
+			break;
+	} while ((bh = bh->b_this_page) != head);
 
-	return 0;
+	return false;
 }
 
 /*
@@ -697,7 +705,7 @@ xfs_convert_page(
 		goto fail_unlock_page;
 	if (page->mapping != inode->i_mapping)
 		goto fail_unlock_page;
-	if (!xfs_check_page_type(page, (*ioendp)->io_type))
+	if (!xfs_check_page_type(page, (*ioendp)->io_type, false))
 		goto fail_unlock_page;
 
 	/*
@@ -742,6 +750,15 @@ xfs_convert_page(
 	p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
 	page_dirty = p_offset / len;
 
+	/*
+	 * The moment we find a buffer that doesn't match our current type
+	 * specification or can't be written, abort the loop and start
+	 * writeback. As per the above xfs_imap_valid() check, only
+	 * xfs_vm_writepage() can handle partial page writeback fully - we are
+	 * limited here to the buffers that are contiguous with the current
+	 * ioend, and hence a buffer we can't write breaks that contiguity and
+	 * we have to defer the rest of the IO to xfs_vm_writepage().
+	 */
 	bh = head = page_buffers(page);
 	do {
 		if (offset >= end_offset)
@@ -750,7 +767,7 @@ xfs_convert_page(
 			uptodate = 0;
 		if (!(PageUptodate(page) || buffer_uptodate(bh))) {
 			done = 1;
-			continue;
+			break;
 		}
 
 		if (buffer_unwritten(bh) || buffer_delay(bh) ||
@@ -762,10 +779,11 @@ xfs_convert_page(
 			else
 				type = XFS_IO_OVERWRITE;
 
-			if (!xfs_imap_valid(inode, imap, offset)) {
-				done = 1;
-				continue;
-			}
+			/*
+			 * imap should always be valid because of the above
+			 * partial page end_offset check on the imap.
+			 */
+			ASSERT(xfs_imap_valid(inode, imap, offset));
 
 			lock_buffer(bh);
 			if (type != XFS_IO_OVERWRITE)
@@ -777,6 +795,7 @@ xfs_convert_page(
 			count++;
 		} else {
 			done = 1;
+			break;
 		}
 	} while (offset += len, (bh = bh->b_this_page) != head);
 
@@ -868,7 +887,7 @@ xfs_aops_discard_page(
 	struct buffer_head	*bh, *head;
 	loff_t			offset = page_offset(page);
 
-	if (!xfs_check_page_type(page, XFS_IO_DELALLOC))
+	if (!xfs_check_page_type(page, XFS_IO_DELALLOC, true))
 		goto out_invalidate;
 
 	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
@@ -1441,7 +1460,8 @@ xfs_vm_direct_IO(
 		ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
 					    offset, nr_segs,
 					    xfs_get_blocks_direct,
-					    xfs_end_io_direct_write, NULL, 0);
+					    xfs_end_io_direct_write, NULL,
+					    DIO_ASYNC_EXTEND);
 		if (ret != -EIOCBQUEUED && iocb->private)
 			goto out_destroy_ioend;
 	} else {