Merge commit 'v2.6.31-rc8' into x86/txt

Conflicts:
	arch/x86/kernel/reboot.c
	security/Kconfig

Merge reason: resolve the conflicts, bump up from rc3 to rc8.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 58 insertions, 49 deletions

diff --git a/fs/ext3/Kconfig b/fs/ext3/Kconfig
index fb3c1a21b13..522b15498f4 100644
--- a/fs/ext3/Kconfig
+++ b/fs/ext3/Kconfig
@@ -29,23 +29,25 @@ config EXT3_FS
 	  module will be called ext3.
 
 config EXT3_DEFAULTS_TO_ORDERED
-	bool "Default to 'data=ordered' in ext3 (legacy option)"
+	bool "Default to 'data=ordered' in ext3"
 	depends on EXT3_FS
 	help
-	  If a filesystem does not explicitly specify a data ordering
-	  mode, and the journal capability allowed it, ext3 used to
-	  historically default to 'data=ordered'.
-
-	  That was a rather unfortunate choice, because it leads to all
-	  kinds of latency problems, and the 'data=writeback' mode is more
-	  appropriate these days.
-
-	  You should probably always answer 'n' here, and if you really
-	  want to use 'data=ordered' mode, set it in the filesystem itself
-	  with 'tune2fs -o journal_data_ordered'.
-
-	  But if you really want to enable the legacy default, you can do
-	  so by answering 'y' to this question.
+	  The journal mode options for ext3 have different tradeoffs
+	  between when data is guaranteed to be on disk and
+	  performance.	The use of "data=writeback" can cause
+	  unwritten data to appear in files after an system crash or
+	  power failure, which can be a security issue.	 However,
+	  "data=ordered" mode can also result in major performance
+	  problems, including seconds-long delays before an fsync()
+	  call returns.	 For details, see:
+
+	  http://ext4.wiki.kernel.org/index.php/Ext3_data_mode_tradeoffs
+
+	  If you have been historically happy with ext3's performance,
+	  data=ordered mode will be a safe choice and you should
+	  answer 'y' here.  If you understand the reliability and data
+	  privacy issues of data=writeback and are willing to make
+	  that trade off, answer 'n'.
 
 config EXT3_FS_XATTR
 	bool "Ext3 extended attributes"
diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c
index 3d724a95882..373fa90c796 100644
--- a/fs/ext3/dir.c
+++ b/fs/ext3/dir.c
@@ -130,8 +130,7 @@ static int ext3_readdir(struct file * filp,
 		struct buffer_head *bh = NULL;
 
 		map_bh.b_state = 0;
-		err = ext3_get_blocks_handle(NULL, inode, blk, 1,
-						&map_bh, 0, 0);
+		err = ext3_get_blocks_handle(NULL, inode, blk, 1, &map_bh, 0);
 		if (err > 0) {
 			pgoff_t index = map_bh.b_blocknr >>
 					(PAGE_CACHE_SHIFT - inode->i_blkbits);
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 5f51fed5c75..b49908a167a 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -788,7 +788,7 @@ err_out:
 int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
 		sector_t iblock, unsigned long maxblocks,
 		struct buffer_head *bh_result,
-		int create, int extend_disksize)
+		int create)
 {
 	int err = -EIO;
 	int offsets[4];
@@ -911,13 +911,6 @@ int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
 	if (!err)
 		err = ext3_splice_branch(handle, inode, iblock,
 					partial, indirect_blks, count);
-	/*
-	 * i_disksize growing is protected by truncate_mutex.  Don't forget to
-	 * protect it if you're about to implement concurrent
-	 * ext3_get_block() -bzzz
-	*/
-	if (!err && extend_disksize && inode->i_size > ei->i_disksize)
-		ei->i_disksize = inode->i_size;
 	mutex_unlock(&ei->truncate_mutex);
 	if (err)
 		goto cleanup;
@@ -972,7 +965,7 @@ static int ext3_get_block(struct inode *inode, sector_t iblock,
 	}
 
 	ret = ext3_get_blocks_handle(handle, inode, iblock,
-					max_blocks, bh_result, create, 0);
+					max_blocks, bh_result, create);
 	if (ret > 0) {
 		bh_result->b_size = (ret << inode->i_blkbits);
 		ret = 0;
@@ -1005,7 +998,7 @@ struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
 	dummy.b_blocknr = -1000;
 	buffer_trace_init(&dummy.b_history);
 	err = ext3_get_blocks_handle(handle, inode, block, 1,
-					&dummy, create, 1);
+					&dummy, create);
 	/*
 	 * ext3_get_blocks_handle() returns number of blocks
 	 * mapped. 0 in case of a HOLE.
@@ -1193,15 +1186,16 @@ write_begin_failed:
 		 * i_size_read because we hold i_mutex.
 		 *
 		 * Add inode to orphan list in case we crash before truncate
-		 * finishes.
+		 * finishes. Do this only if ext3_can_truncate() agrees so
+		 * that orphan processing code is happy.
 		 */
-		if (pos + len > inode->i_size)
+		if (pos + len > inode->i_size && ext3_can_truncate(inode))
 			ext3_orphan_add(handle, inode);
 		ext3_journal_stop(handle);
 		unlock_page(page);
 		page_cache_release(page);
 		if (pos + len > inode->i_size)
-			vmtruncate(inode, inode->i_size);
+			ext3_truncate(inode);
 	}
 	if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;
@@ -1287,7 +1281,7 @@ static int ext3_ordered_write_end(struct file *file,
 	 * There may be allocated blocks outside of i_size because
 	 * we failed to copy some data. Prepare for truncate.
 	 */
-	if (pos + len > inode->i_size)
+	if (pos + len > inode->i_size && ext3_can_truncate(inode))
 		ext3_orphan_add(handle, inode);
 	ret2 = ext3_journal_stop(handle);
 	if (!ret)
@@ -1296,7 +1290,7 @@ static int ext3_ordered_write_end(struct file *file,
 	page_cache_release(page);
 
 	if (pos + len > inode->i_size)
-		vmtruncate(inode, inode->i_size);
+		ext3_truncate(inode);
 	return ret ? ret : copied;
 }
 
@@ -1315,14 +1309,14 @@ static int ext3_writeback_write_end(struct file *file,
 	 * There may be allocated blocks outside of i_size because
 	 * we failed to copy some data. Prepare for truncate.
 	 */
-	if (pos + len > inode->i_size)
+	if (pos + len > inode->i_size && ext3_can_truncate(inode))
 		ext3_orphan_add(handle, inode);
 	ret = ext3_journal_stop(handle);
 	unlock_page(page);
 	page_cache_release(page);
 
 	if (pos + len > inode->i_size)
-		vmtruncate(inode, inode->i_size);
+		ext3_truncate(inode);
 	return ret ? ret : copied;
 }
 
@@ -1358,7 +1352,7 @@ static int ext3_journalled_write_end(struct file *file,
 	 * There may be allocated blocks outside of i_size because
 	 * we failed to copy some data. Prepare for truncate.
 	 */
-	if (pos + len > inode->i_size)
+	if (pos + len > inode->i_size && ext3_can_truncate(inode))
 		ext3_orphan_add(handle, inode);
 	EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
 	if (inode->i_size > EXT3_I(inode)->i_disksize) {
@@ -1375,7 +1369,7 @@ static int ext3_journalled_write_end(struct file *file,
 	page_cache_release(page);
 
 	if (pos + len > inode->i_size)
-		vmtruncate(inode, inode->i_size);
+		ext3_truncate(inode);
 	return ret ? ret : copied;
 }
 
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 524b349c629..a8d80a7f110 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -543,6 +543,19 @@ static inline void ext3_show_quota_options(struct seq_file *seq, struct super_bl
 #endif
 }
 
+static char *data_mode_string(unsigned long mode)
+{
+	switch (mode) {
+	case EXT3_MOUNT_JOURNAL_DATA:
+		return "journal";
+	case EXT3_MOUNT_ORDERED_DATA:
+		return "ordered";
+	case EXT3_MOUNT_WRITEBACK_DATA:
+		return "writeback";
+	}
+	return "unknown";
+}
+
 /*
  * Show an option if
  *  - it's set to a non-default value OR
@@ -616,13 +629,8 @@ static int ext3_show_options(struct seq_file *seq, struct vfsmount *vfs)
 	if (test_opt(sb, NOBH))
 		seq_puts(seq, ",nobh");
 
-	if (test_opt(sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA)
-		seq_puts(seq, ",data=journal");
-	else if (test_opt(sb, DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA)
-		seq_puts(seq, ",data=ordered");
-	else if (test_opt(sb, DATA_FLAGS) == EXT3_MOUNT_WRITEBACK_DATA)
-		seq_puts(seq, ",data=writeback");
-
+	seq_printf(seq, ",data=%s", data_mode_string(sbi->s_mount_opt &
+						     EXT3_MOUNT_DATA_FLAGS));
 	if (test_opt(sb, DATA_ERR_ABORT))
 		seq_puts(seq, ",data_err=abort");
 
@@ -1024,12 +1032,18 @@ static int parse_options (char *options, struct super_block *sb,
 		datacheck:
 			if (is_remount) {
 				if ((sbi->s_mount_opt & EXT3_MOUNT_DATA_FLAGS)
-						!= data_opt) {
-					printk(KERN_ERR
-						"EXT3-fs: cannot change data "
-						"mode on remount\n");
-					return 0;
-				}
+						== data_opt)
+					break;
+				printk(KERN_ERR
+					"EXT3-fs (device %s): Cannot change "
+					"data mode on remount. The filesystem "
+					"is mounted in data=%s mode and you "
+					"try to remount it in data=%s mode.\n",
+					sb->s_id,
+					data_mode_string(sbi->s_mount_opt &
+							EXT3_MOUNT_DATA_FLAGS),
+					data_mode_string(data_opt));
+				return 0;
 			} else {
 				sbi->s_mount_opt &= ~EXT3_MOUNT_DATA_FLAGS;
 				sbi->s_mount_opt |= data_opt;