Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: only run xfs_error_test if error injection is active
  xfs: avoid moving stale inodes in the AIL
  xfs: delayed alloc blocks beyond EOF are valid after writeback
  xfs: push stale, pinned buffers on trylock failures
  xfs: fix failed write truncation handling.

8 files changed, 188 insertions, 83 deletions

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 7d287af..691f612 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -934,7 +934,6 @@ xfs_aops_discard_page(
 	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, IO_DELAY))
 		goto out_invalidate;
@@ -949,58 +948,14 @@ xfs_aops_discard_page(
 	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;
+		xfs_fileoff_t	start_fsb;
 
 		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);
-
-		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, &done);
-
-		ASSERT(!flist.xbf_count && !flist.xbf_first);
+		start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
+		error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
 		if (error) {
 			/* something screwed, just bail */
 			if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
@@ -1010,7 +965,7 @@ xfs_aops_discard_page(
 			break;
 		}
 next_buffer:
-		offset += len;
+		offset += 1 << inode->i_blkbits;
 
 	} while ((bh = bh->b_this_page) != head);
 
@@ -1505,11 +1460,42 @@ xfs_vm_write_failed(
 	struct inode		*inode = mapping->host;
 
 	if (to > inode->i_size) {
-		struct iattr	ia = {
-			.ia_valid	= ATTR_SIZE | ATTR_FORCE,
-			.ia_size	= inode->i_size,
-		};
-		xfs_setattr(XFS_I(inode), &ia, XFS_ATTR_NOLOCK);
+		/*
+		 * punch out the delalloc blocks we have already allocated. We
+		 * don't call xfs_setattr() to do this as we may be in the
+		 * middle of a multi-iovec write and so the vfs inode->i_size
+		 * will not match the xfs ip->i_size and so it will zero too
+		 * much. Hence we jus truncate the page cache to zero what is
+		 * necessary and punch the delalloc blocks directly.
+		 */
+		struct xfs_inode	*ip = XFS_I(inode);
+		xfs_fileoff_t		start_fsb;
+		xfs_fileoff_t		end_fsb;
+		int			error;
+
+		truncate_pagecache(inode, to, inode->i_size);
+
+		/*
+		 * Check if there are any blocks that are outside of i_size
+		 * that need to be trimmed back.
+		 */
+		start_fsb = XFS_B_TO_FSB(ip->i_mount, inode->i_size) + 1;
+		end_fsb = XFS_B_TO_FSB(ip->i_mount, to);
+		if (end_fsb <= start_fsb)
+			return;
+
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+		error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
+							end_fsb - start_fsb);
+		if (error) {
+			/* something screwed, just bail */
+			if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+				xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+			"xfs_vm_write_failed: unable to clean up ino %lld",
+						ip->i_ino);
+			}
+		}
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
 	}
 }
 
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index aa1d353..4c5deb6 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -488,29 +488,16 @@ found:
 	spin_unlock(&pag->pag_buf_lock);
 	xfs_perag_put(pag);
 
-	/* Attempt to get the semaphore without sleeping,
-	 * if this does not work then we need to drop the
-	 * spinlock and do a hard attempt on the semaphore.
-	 */
-	if (down_trylock(&bp->b_sema)) {
+	if (xfs_buf_cond_lock(bp)) {
+		/* failed, so wait for the lock if requested. */
 		if (!(flags & XBF_TRYLOCK)) {
-			/* wait for buffer ownership */
 			xfs_buf_lock(bp);
 			XFS_STATS_INC(xb_get_locked_waited);
 		} else {
-			/* We asked for a trylock and failed, no need
-			 * to look at file offset and length here, we
-			 * know that this buffer at least overlaps our
-			 * buffer and is locked, therefore our buffer
-			 * either does not exist, or is this buffer.
-			 */
 			xfs_buf_rele(bp);
 			XFS_STATS_INC(xb_busy_locked);
 			return NULL;
 		}
-	} else {
-		/* trylock worked */
-		XB_SET_OWNER(bp);
 	}
 
 	if (bp->b_flags & XBF_STALE) {
@@ -876,10 +863,18 @@ xfs_buf_rele(
  */
 
 /*
- *	Locks a buffer object, if it is not already locked.
- *	Note that this in no way locks the underlying pages, so it is only
- *	useful for synchronizing concurrent use of buffer objects, not for
- *	synchronizing independent access to the underlying pages.
+ *	Locks a buffer object, if it is not already locked.  Note that this in
+ *	no way locks the underlying pages, so it is only useful for
+ *	synchronizing concurrent use of buffer objects, not for synchronizing
+ *	independent access to the underlying pages.
+ *
+ *	If we come across a stale, pinned, locked buffer, we know that we are
+ *	being asked to lock a buffer that has been reallocated. Because it is
+ *	pinned, we know that the log has not been pushed to disk and hence it
+ *	will still be locked.  Rather than continuing to have trylock attempts
+ *	fail until someone else pushes the log, push it ourselves before
+ *	returning.  This means that the xfsaild will not get stuck trying
+ *	to push on stale inode buffers.
  */
 int
 xfs_buf_cond_lock(
@@ -890,6 +885,8 @@ xfs_buf_cond_lock(
 	locked = down_trylock(&bp->b_sema) == 0;
 	if (locked)
 		XB_SET_OWNER(bp);
+	else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE))
+		xfs_log_force(bp->b_target->bt_mount, 0);
 
 	trace_xfs_buf_cond_lock(bp, _RET_IP_);
 	return locked ? 0 : -EBUSY;
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 8abd12e..4111cd3 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -5471,8 +5471,13 @@ xfs_getbmap(
 			if (error)
 				goto out_unlock_iolock;
 		}
-
-		ASSERT(ip->i_delayed_blks == 0);
+		/*
+		 * even after flushing the inode, there can still be delalloc
+		 * blocks on the inode beyond EOF due to speculative
+		 * preallocation. These are not removed until the release
+		 * function is called or the inode is inactivated. Hence we
+		 * cannot assert here that ip->i_delayed_blks == 0.
+		 */
 	}
 
 	lock = xfs_ilock_map_shared(ip);
@@ -6070,3 +6075,79 @@ xfs_bmap_disk_count_leaves(
 		*count += xfs_bmbt_disk_get_blockcount(frp);
 	}
 }
+
+/*
+ * dead simple method of punching delalyed allocation blocks from a range in
+ * the inode. Walks a block at a time so will be slow, but is only executed in
+ * rare error cases so the overhead is not critical. This will alays punch out
+ * both the start and end blocks, even if the ranges only partially overlap
+ * them, so it is up to the caller to ensure that partial blocks are not
+ * passed in.
+ */
+int
+xfs_bmap_punch_delalloc_range(
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		start_fsb,
+	xfs_fileoff_t		length)
+{
+	xfs_fileoff_t		remaining = length;
+	int			error = 0;
+
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	do {
+		int		done;
+		xfs_bmbt_irec_t	imap;
+		int		nimaps = 1;
+		xfs_fsblock_t	firstblock;
+		xfs_bmap_free_t flist;
+
+		/*
+		 * 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, start_fsb, 1,
+				XFS_BMAPI_ENTIRE,  NULL, 0, &imap,
+				&nimaps, NULL);
+
+		if (error) {
+			/* something screwed, just bail */
+			if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+				xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+			"Failed delalloc mapping lookup ino %lld fsb %lld.",
+						ip->i_ino, start_fsb);
+			}
+			break;
+		}
+		if (!nimaps) {
+			/* nothing there */
+			goto next_block;
+		}
+		if (imap.br_startblock != DELAYSTARTBLOCK) {
+			/* been converted, ignore */
+			goto next_block;
+		}
+		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, start_fsb, 1, 0, 1, &firstblock,
+					&flist, &done);
+		if (error)
+			break;
+
+		ASSERT(!flist.xbf_count && !flist.xbf_first);
+next_block:
+		start_fsb++;
+		remaining--;
+	} while(remaining > 0);
+
+	return error;
+}
diff --git a/fs/xfs/xfs_bmap.h b/fs/xfs/xfs_bmap.h
index 71ec9b6..3651191 100644
--- a/fs/xfs/xfs_bmap.h
+++ b/fs/xfs/xfs_bmap.h
@@ -394,6 +394,11 @@ xfs_bmap_count_blocks(
 	int			whichfork,
 	int			*count);
 
+int
+xfs_bmap_punch_delalloc_range(
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		start_fsb,
+	xfs_fileoff_t		length);
 #endif	/* __KERNEL__ */
 
 #endif	/* __XFS_BMAP_H__ */
diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c
index 3b9582c..e60490b 100644
--- a/fs/xfs/xfs_dfrag.c
+++ b/fs/xfs/xfs_dfrag.c
@@ -377,6 +377,19 @@ xfs_swap_extents(
 	ip->i_d.di_format = tip->i_d.di_format;
 	tip->i_d.di_format = tmp;
 
+	/*
+	 * The extents in the source inode could still contain speculative
+	 * preallocation beyond EOF (e.g. the file is open but not modified
+	 * while defrag is in progress). In that case, we need to copy over the
+	 * number of delalloc blocks the data fork in the source inode is
+	 * tracking beyond EOF so that when the fork is truncated away when the
+	 * temporary inode is unlinked we don't underrun the i_delayed_blks
+	 * counter on that inode.
+	 */
+	ASSERT(tip->i_delayed_blks == 0);
+	tip->i_delayed_blks = ip->i_delayed_blks;
+	ip->i_delayed_blks = 0;
+
 	ilf_fields = XFS_ILOG_CORE;
 
 	switch(ip->i_d.di_format) {
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index ed99902..c78cc6a 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -58,6 +58,7 @@ xfs_error_trap(int e)
 int	xfs_etest[XFS_NUM_INJECT_ERROR];
 int64_t	xfs_etest_fsid[XFS_NUM_INJECT_ERROR];
 char *	xfs_etest_fsname[XFS_NUM_INJECT_ERROR];
+int	xfs_error_test_active;
 
 int
 xfs_error_test(int error_tag, int *fsidp, char *expression,
@@ -108,6 +109,7 @@ xfs_errortag_add(int error_tag, xfs_mount_t *mp)
 			len = strlen(mp->m_fsname);
 			xfs_etest_fsname[i] = kmem_alloc(len + 1, KM_SLEEP);
 			strcpy(xfs_etest_fsname[i], mp->m_fsname);
+			xfs_error_test_active++;
 			return 0;
 		}
 	}
@@ -137,6 +139,7 @@ xfs_errortag_clearall(xfs_mount_t *mp, int loud)
 			xfs_etest_fsid[i] = 0LL;
 			kmem_free(xfs_etest_fsname[i]);
 			xfs_etest_fsname[i] = NULL;
+			xfs_error_test_active--;
 		}
 	}
 
diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
index c2c1a07..f338847 100644
--- a/fs/xfs/xfs_error.h
+++ b/fs/xfs/xfs_error.h
@@ -127,13 +127,14 @@ extern void xfs_corruption_error(const char *tag, int level,
 #define	XFS_RANDOM_BMAPIFORMAT				XFS_RANDOM_DEFAULT
 
 #ifdef DEBUG
+extern int xfs_error_test_active;
 extern int xfs_error_test(int, int *, char *, int, char *, unsigned long);
 
 #define	XFS_NUM_INJECT_ERROR				10
 #define XFS_TEST_ERROR(expr, mp, tag, rf)		\
-	((expr) || \
+	((expr) || (xfs_error_test_active && \
 	 xfs_error_test((tag), (mp)->m_fixedfsid, "expr", __LINE__, __FILE__, \
-			(rf)))
+			(rf))))
 
 extern int xfs_errortag_add(int error_tag, xfs_mount_t *mp);
 extern int xfs_errortag_clearall(xfs_mount_t *mp, int loud);
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index c7ac020..7c8d30c 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -657,18 +657,37 @@ xfs_inode_item_unlock(
 }
 
 /*
- * This is called to find out where the oldest active copy of the
- * inode log item in the on disk log resides now that the last log
- * write of it completed at the given lsn.  Since we always re-log
- * all dirty data in an inode, the latest copy in the on disk log
- * is the only one that matters.  Therefore, simply return the
- * given lsn.
+ * This is called to find out where the oldest active copy of the inode log
+ * item in the on disk log resides now that the last log write of it completed
+ * at the given lsn.  Since we always re-log all dirty data in an inode, the
+ * latest copy in the on disk log is the only one that matters.  Therefore,
+ * simply return the given lsn.
+ *
+ * If the inode has been marked stale because the cluster is being freed, we
+ * don't want to (re-)insert this inode into the AIL. There is a race condition
+ * where the cluster buffer may be unpinned before the inode is inserted into
+ * the AIL during transaction committed processing. If the buffer is unpinned
+ * before the inode item has been committed and inserted, then it is possible
+ * for the buffer to be written and IO completions before the inode is inserted
+ * into the AIL. In that case, we'd be inserting a clean, stale inode into the
+ * AIL which will never get removed. It will, however, get reclaimed which
+ * triggers an assert in xfs_inode_free() complaining about freein an inode
+ * still in the AIL.
+ *
+ * To avoid this, return a lower LSN than the one passed in so that the
+ * transaction committed code will not move the inode forward in the AIL but
+ * will still unpin it properly.
  */
 STATIC xfs_lsn_t
 xfs_inode_item_committed(
 	struct xfs_log_item	*lip,
 	xfs_lsn_t		lsn)
 {
+	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
+	struct xfs_inode	*ip = iip->ili_inode;
+
+	if (xfs_iflags_test(ip, XFS_ISTALE))
+		return lsn - 1;
 	return lsn;
 }