1 files changed, 234 insertions, 181 deletions

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 381854461b28..99628508cb11 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -38,6 +38,8 @@
 #include "xfs_rw.h"
 #include "xfs_iomap.h"
 #include "xfs_vnodeops.h"
+#include "xfs_trace.h"
+#include "xfs_bmap.h"
 #include <linux/mpage.h>
 #include <linux/pagevec.h>
 #include <linux/writeback.h>
@@ -76,7 +78,7 @@ xfs_ioend_wake(
 		wake_up(to_ioend_wq(ip));
 }
 
-STATIC void
+void
 xfs_count_page_state(
 	struct page		*page,
 	int			*delalloc,
@@ -98,48 +100,6 @@ xfs_count_page_state(
 	} while ((bh = bh->b_this_page) != head);
 }
 
-#if defined(XFS_RW_TRACE)
-void
-xfs_page_trace(
-	int		tag,
-	struct inode	*inode,
-	struct page	*page,
-	unsigned long	pgoff)
-{
-	xfs_inode_t	*ip;
-	loff_t		isize = i_size_read(inode);
-	loff_t		offset = page_offset(page);
-	int		delalloc = -1, unmapped = -1, unwritten = -1;
-
-	if (page_has_buffers(page))
-		xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
-
-	ip = XFS_I(inode);
-	if (!ip->i_rwtrace)
-		return;
-
-	ktrace_enter(ip->i_rwtrace,
-		(void *)((unsigned long)tag),
-		(void *)ip,
-		(void *)inode,
-		(void *)page,
-		(void *)pgoff,
-		(void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
-		(void *)((unsigned long)((isize >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(isize & 0xffffffff)),
-		(void *)((unsigned long)((offset >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(offset & 0xffffffff)),
-		(void *)((unsigned long)delalloc),
-		(void *)((unsigned long)unmapped),
-		(void *)((unsigned long)unwritten),
-		(void *)((unsigned long)current_pid()),
-		(void *)NULL);
-}
-#else
-#define xfs_page_trace(tag, inode, page, pgoff)
-#endif
-
 STATIC struct block_device *
 xfs_find_bdev_for_inode(
 	struct xfs_inode	*ip)
@@ -186,109 +146,58 @@ xfs_destroy_ioend(
 }
 
 /*
- * Update on-disk file size now that data has been written to disk.
- * The current in-memory file size is i_size.  If a write is beyond
- * eof i_new_size will be the intended file size until i_size is
- * updated.  If this write does not extend all the way to the valid
- * file size then restrict this update to the end of the write.
+ * If the end of the current ioend is beyond the current EOF,
+ * return the new EOF value, otherwise zero.
  */
-STATIC void
-xfs_setfilesize(
+STATIC xfs_fsize_t
+xfs_ioend_new_eof(
 	xfs_ioend_t		*ioend)
 {
 	xfs_inode_t		*ip = XFS_I(ioend->io_inode);
 	xfs_fsize_t		isize;
 	xfs_fsize_t		bsize;
 
-	ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
-	ASSERT(ioend->io_type != IOMAP_READ);
-
-	if (unlikely(ioend->io_error))
-		return;
-
 	bsize = ioend->io_offset + ioend->io_size;
-
-	xfs_ilock(ip, XFS_ILOCK_EXCL);
-
 	isize = MAX(ip->i_size, ip->i_new_size);
 	isize = MIN(isize, bsize);
-
-	if (ip->i_d.di_size < isize) {
-		ip->i_d.di_size = isize;
-		ip->i_update_core = 1;
-		xfs_mark_inode_dirty_sync(ip);
-	}
-
-	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	return isize > ip->i_d.di_size ? isize : 0;
 }
 
 /*
- * Buffered IO write completion for delayed allocate extents.
+ * Update on-disk file size now that data has been written to disk.  The
+ * current in-memory file size is i_size.  If a write is beyond eof i_new_size
+ * will be the intended file size until i_size is updated.  If this write does
+ * not extend all the way to the valid file size then restrict this update to
+ * the end of the write.
+ *
+ * This function does not block as blocking on the inode lock in IO completion
+ * can lead to IO completion order dependency deadlocks.. If it can't get the
+ * inode ilock it will return EAGAIN. Callers must handle this.
  */
-STATIC void
-xfs_end_bio_delalloc(
-	struct work_struct	*work)
+STATIC int
+xfs_setfilesize(
+	xfs_ioend_t		*ioend)
 {
-	xfs_ioend_t		*ioend =
-		container_of(work, xfs_ioend_t, io_work);
+	xfs_inode_t		*ip = XFS_I(ioend->io_inode);
+	xfs_fsize_t		isize;
 
-	xfs_setfilesize(ioend);
-	xfs_destroy_ioend(ioend);
-}
+	ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
+	ASSERT(ioend->io_type != IOMAP_READ);
 
-/*
- * Buffered IO write completion for regular, written extents.
- */
-STATIC void
-xfs_end_bio_written(
-	struct work_struct	*work)
-{
-	xfs_ioend_t		*ioend =
-		container_of(work, xfs_ioend_t, io_work);
+	if (unlikely(ioend->io_error))
+		return 0;
 
-	xfs_setfilesize(ioend);
-	xfs_destroy_ioend(ioend);
-}
+	if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
+		return EAGAIN;
 
-/*
- * IO write completion for unwritten extents.
- *
- * Issue transactions to convert a buffer range from unwritten
- * to written extents.
- */
-STATIC void
-xfs_end_bio_unwritten(
-	struct work_struct	*work)
-{
-	xfs_ioend_t		*ioend =
-		container_of(work, xfs_ioend_t, io_work);
-	struct xfs_inode	*ip = XFS_I(ioend->io_inode);
-	xfs_off_t		offset = ioend->io_offset;
-	size_t			size = ioend->io_size;
-
-	if (likely(!ioend->io_error)) {
-		if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
-			int error;
-			error = xfs_iomap_write_unwritten(ip, offset, size);
-			if (error)
-				ioend->io_error = error;
-		}
-		xfs_setfilesize(ioend);
+	isize = xfs_ioend_new_eof(ioend);
+	if (isize) {
+		ip->i_d.di_size = isize;
+		xfs_mark_inode_dirty(ip);
 	}
-	xfs_destroy_ioend(ioend);
-}
-
-/*
- * IO read completion for regular, written extents.
- */
-STATIC void
-xfs_end_bio_read(
-	struct work_struct	*work)
-{
-	xfs_ioend_t		*ioend =
-		container_of(work, xfs_ioend_t, io_work);
 
-	xfs_destroy_ioend(ioend);
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	return 0;
 }
 
 /*
@@ -302,10 +211,10 @@ xfs_finish_ioend(
 	int		wait)
 {
 	if (atomic_dec_and_test(&ioend->io_remaining)) {
-		struct workqueue_struct *wq = xfsdatad_workqueue;
-		if (ioend->io_work.func == xfs_end_bio_unwritten)
-			wq = xfsconvertd_workqueue;
+		struct workqueue_struct *wq;
 
+		wq = (ioend->io_type == IOMAP_UNWRITTEN) ?
+			xfsconvertd_workqueue : xfsdatad_workqueue;
 		queue_work(wq, &ioend->io_work);
 		if (wait)
 			flush_workqueue(wq);
@@ -313,6 +222,53 @@ xfs_finish_ioend(
 }
 
 /*
+ * IO write completion.
+ */
+STATIC void
+xfs_end_io(
+	struct work_struct *work)
+{
+	xfs_ioend_t	*ioend = container_of(work, xfs_ioend_t, io_work);
+	struct xfs_inode *ip = XFS_I(ioend->io_inode);
+	int		error = 0;
+
+	/*
+	 * For unwritten extents we need to issue transactions to convert a
+	 * range to normal written extens after the data I/O has finished.
+	 */
+	if (ioend->io_type == IOMAP_UNWRITTEN &&
+	    likely(!ioend->io_error && !XFS_FORCED_SHUTDOWN(ip->i_mount))) {
+
+		error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
+						 ioend->io_size);
+		if (error)
+			ioend->io_error = error;
+	}
+
+	/*
+	 * We might have to update the on-disk file size after extending
+	 * writes.
+	 */
+	if (ioend->io_type != IOMAP_READ) {
+		error = xfs_setfilesize(ioend);
+		ASSERT(!error || error == EAGAIN);
+	}
+
+	/*
+	 * If we didn't complete processing of the ioend, requeue it to the
+	 * tail of the workqueue for another attempt later. Otherwise destroy
+	 * it.
+	 */
+	if (error == EAGAIN) {
+		atomic_inc(&ioend->io_remaining);
+		xfs_finish_ioend(ioend, 0);
+		/* ensure we don't spin on blocked ioends */
+		delay(1);
+	} else
+		xfs_destroy_ioend(ioend);
+}
+
+/*
  * Allocate and initialise an IO completion structure.
  * We need to track unwritten extent write completion here initially.
  * We'll need to extend this for updating the ondisk inode size later
@@ -343,15 +299,7 @@ xfs_alloc_ioend(
 	ioend->io_offset = 0;
 	ioend->io_size = 0;
 
-	if (type == IOMAP_UNWRITTEN)
-		INIT_WORK(&ioend->io_work, xfs_end_bio_unwritten);
-	else if (type == IOMAP_DELAY)
-		INIT_WORK(&ioend->io_work, xfs_end_bio_delalloc);
-	else if (type == IOMAP_READ)
-		INIT_WORK(&ioend->io_work, xfs_end_bio_read);
-	else
-		INIT_WORK(&ioend->io_work, xfs_end_bio_written);
-
+	INIT_WORK(&ioend->io_work, xfs_end_io);
 	return ioend;
 }
 
@@ -368,7 +316,7 @@ xfs_map_blocks(
 	return -xfs_iomap(XFS_I(inode), offset, count, flags, mapp, &nmaps);
 }
 
-STATIC_INLINE int
+STATIC int
 xfs_iomap_valid(
 	xfs_iomap_t		*iomapp,
 	loff_t			offset)
@@ -400,15 +348,23 @@ xfs_end_bio(
 
 STATIC void
 xfs_submit_ioend_bio(
-	xfs_ioend_t	*ioend,
-	struct bio	*bio)
+	struct writeback_control *wbc,
+	xfs_ioend_t		*ioend,
+	struct bio		*bio)
 {
 	atomic_inc(&ioend->io_remaining);
-
 	bio->bi_private = ioend;
 	bio->bi_end_io = xfs_end_bio;
 
-	submit_bio(WRITE, bio);
+	/*
+	 * If the I/O is beyond EOF we mark the inode dirty immediately
+	 * but don't update the inode size until I/O completion.
+	 */
+	if (xfs_ioend_new_eof(ioend))
+		xfs_mark_inode_dirty(XFS_I(ioend->io_inode));
+
+	submit_bio(wbc->sync_mode == WB_SYNC_ALL ?
+		   WRITE_SYNC_PLUG : WRITE, bio);
 	ASSERT(!bio_flagged(bio, BIO_EOPNOTSUPP));
 	bio_put(bio);
 }
@@ -487,6 +443,7 @@ static inline int bio_add_buffer(struct bio *bio, struct buffer_head *bh)
  */
 STATIC void
 xfs_submit_ioend(
+	struct writeback_control *wbc,
 	xfs_ioend_t		*ioend)
 {
 	xfs_ioend_t		*head = ioend;
@@ -515,19 +472,19 @@ xfs_submit_ioend(
  retry:
 				bio = xfs_alloc_ioend_bio(bh);
 			} else if (bh->b_blocknr != lastblock + 1) {
-				xfs_submit_ioend_bio(ioend, bio);
+				xfs_submit_ioend_bio(wbc, ioend, bio);
 				goto retry;
 			}
 
 			if (bio_add_buffer(bio, bh) != bh->b_size) {
-				xfs_submit_ioend_bio(ioend, bio);
+				xfs_submit_ioend_bio(wbc, ioend, bio);
 				goto retry;
 			}
 
 			lastblock = bh->b_blocknr;
 		}
 		if (bio)
-			xfs_submit_ioend_bio(ioend, bio);
+			xfs_submit_ioend_bio(wbc, ioend, bio);
 		xfs_finish_ioend(ioend, 0);
 	} while ((ioend = next) != NULL);
 }
@@ -886,16 +843,9 @@ xfs_convert_page(
 
 	if (startio) {
 		if (count) {
-			struct backing_dev_info *bdi;
-
-			bdi = inode->i_mapping->backing_dev_info;
 			wbc->nr_to_write--;
-			if (bdi_write_congested(bdi)) {
-				wbc->encountered_congestion = 1;
-				done = 1;
-			} else if (wbc->nr_to_write <= 0) {
+			if (wbc->nr_to_write <= 0)
 				done = 1;
-			}
 		}
 		xfs_start_page_writeback(page, !page_dirty, count);
 	}
@@ -944,6 +894,125 @@ xfs_cluster_write(
 	}
 }
 
+STATIC void
+xfs_vm_invalidatepage(
+	struct page		*page,
+	unsigned long		offset)
+{
+	trace_xfs_invalidatepage(page->mapping->host, page, offset);
+	block_invalidatepage(page, offset);
+}
+
+/*
+ * If the page has delalloc buffers on it, we need to punch them out before we
+ * invalidate the page. If we don't, we leave a stale delalloc mapping on the
+ * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
+ * is done on that same region - the delalloc extent is returned when none is
+ * supposed to be there.
+ *
+ * We prevent this by truncating away the delalloc regions on the page before
+ * invalidating it. Because they are delalloc, we can do this without needing a
+ * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
+ * truncation without a transaction as there is no space left for block
+ * reservation (typically why we see a ENOSPC in writeback).
+ *
+ * This is not a performance critical path, so for now just do the punching a
+ * buffer head at a time.
+ */
+STATIC void
+xfs_aops_discard_page(
+	struct page		*page)
+{
+	struct inode		*inode = page->mapping->host;
+	struct xfs_inode	*ip = XFS_I(inode);
+	struct buffer_head	*bh, *head;
+	loff_t			offset = page_offset(page);
+	ssize_t			len = 1 << inode->i_blkbits;
+
+	if (!xfs_is_delayed_page(page, IOMAP_DELAY))
+		goto out_invalidate;
+
+	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+		goto out_invalidate;
+
+	xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+		"page discard on page %p, inode 0x%llx, offset %llu.",
+			page, ip->i_ino, offset);
+
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	bh = head = page_buffers(page);
+	do {
+		int		done;
+		xfs_fileoff_t	offset_fsb;
+		xfs_bmbt_irec_t	imap;
+		int		nimaps = 1;
+		int		error;
+		xfs_fsblock_t	firstblock;
+		xfs_bmap_free_t flist;
+
+		if (!buffer_delay(bh))
+			goto next_buffer;
+
+		offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
+
+		/*
+		 * Map the range first and check that it is a delalloc extent
+		 * before trying to unmap the range. Otherwise we will be
+		 * trying to remove a real extent (which requires a
+		 * transaction) or a hole, which is probably a bad idea...
+		 */
+		error = xfs_bmapi(NULL, ip, offset_fsb, 1,
+				XFS_BMAPI_ENTIRE,  NULL, 0, &imap,
+				&nimaps, NULL, NULL);
+
+		if (error) {
+			/* something screwed, just bail */
+			if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+				xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+				"page discard failed delalloc mapping lookup.");
+			}
+			break;
+		}
+		if (!nimaps) {
+			/* nothing there */
+			goto next_buffer;
+		}
+		if (imap.br_startblock != DELAYSTARTBLOCK) {
+			/* been converted, ignore */
+			goto next_buffer;
+		}
+		WARN_ON(imap.br_blockcount == 0);
+
+		/*
+		 * Note: while we initialise the firstblock/flist pair, they
+		 * should never be used because blocks should never be
+		 * allocated or freed for a delalloc extent and hence we need
+		 * don't cancel or finish them after the xfs_bunmapi() call.
+		 */
+		xfs_bmap_init(&flist, &firstblock);
+		error = xfs_bunmapi(NULL, ip, offset_fsb, 1, 0, 1, &firstblock,
+					&flist, NULL, &done);
+
+		ASSERT(!flist.xbf_count && !flist.xbf_first);
+		if (error) {
+			/* something screwed, just bail */
+			if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+				xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+			"page discard unable to remove delalloc mapping.");
+			}
+			break;
+		}
+next_buffer:
+		offset += len;
+
+	} while ((bh = bh->b_this_page) != head);
+
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+out_invalidate:
+	xfs_vm_invalidatepage(page, 0);
+	return;
+}
+
 /*
  * Calling this without startio set means we are being asked to make a dirty
  * page ready for freeing it's buffers.  When called with startio set then
@@ -1180,7 +1249,7 @@ xfs_page_state_convert(
 	}
 
 	if (iohead)
-		xfs_submit_ioend(iohead);
+		xfs_submit_ioend(wbc, iohead);
 
 	return page_dirty;
 
@@ -1195,7 +1264,7 @@ error:
 	 */
 	if (err != -EAGAIN) {
 		if (!unmapped)
-			block_invalidatepage(page, 0);
+			xfs_aops_discard_page(page);
 		ClearPageUptodate(page);
 	}
 	return err;
@@ -1231,7 +1300,7 @@ xfs_vm_writepage(
 	int			delalloc, unmapped, unwritten;
 	struct inode		*inode = page->mapping->host;
 
-	xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
+	trace_xfs_writepage(inode, page, 0);
 
 	/*
 	 * We need a transaction if:
@@ -1336,7 +1405,7 @@ xfs_vm_releasepage(
 		.nr_to_write = 1,
 	};
 
-	xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, 0);
+	trace_xfs_releasepage(inode, page, 0);
 
 	if (!page_has_buffers(page))
 		return 0;
@@ -1517,7 +1586,7 @@ xfs_end_io_direct(
 		 * didn't map an unwritten extent so switch it's completion
 		 * handler.
 		 */
-		INIT_WORK(&ioend->io_work, xfs_end_bio_written);
+		ioend->io_type = IOMAP_NEW;
 		xfs_finish_ioend(ioend, 0);
 	}
 
@@ -1544,19 +1613,13 @@ xfs_vm_direct_IO(
 
 	bdev = xfs_find_bdev_for_inode(XFS_I(inode));
 
-	if (rw == WRITE) {
-		iocb->private = xfs_alloc_ioend(inode, IOMAP_UNWRITTEN);
-		ret = blockdev_direct_IO_own_locking(rw, iocb, inode,
-			bdev, iov, offset, nr_segs,
-			xfs_get_blocks_direct,
-			xfs_end_io_direct);
-	} else {
-		iocb->private = xfs_alloc_ioend(inode, IOMAP_READ);
-		ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
-			bdev, iov, offset, nr_segs,
-			xfs_get_blocks_direct,
-			xfs_end_io_direct);
-	}
+	iocb->private = xfs_alloc_ioend(inode, rw == WRITE ?
+					IOMAP_UNWRITTEN : IOMAP_READ);
+
+	ret = blockdev_direct_IO_no_locking(rw, iocb, inode, bdev, iov,
+					    offset, nr_segs,
+					    xfs_get_blocks_direct,
+					    xfs_end_io_direct);
 
 	if (unlikely(ret != -EIOCBQUEUED && iocb->private))
 		xfs_destroy_ioend(iocb->private);
@@ -1611,16 +1674,6 @@ xfs_vm_readpages(
 	return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
 }
 
-STATIC void
-xfs_vm_invalidatepage(
-	struct page		*page,
-	unsigned long		offset)
-{
-	xfs_page_trace(XFS_INVALIDPAGE_ENTER,
-			page->mapping->host, page, offset);
-	block_invalidatepage(page, offset);
-}
-
 const struct address_space_operations xfs_address_space_operations = {
 	.readpage		= xfs_vm_readpage,
 	.readpages		= xfs_vm_readpages,