linux-ext4 - [PATCH 03/10 v5] ext4: let ext4_ext_map_blocks return EXT4_MAP

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Date:	Fri,  8 Feb 2013 16:43:59 +0800
From:	Zheng Liu <gnehzuil.liu@...il.com>
To:	linux-ext4@...r.kernel.org
Cc:	Zheng Liu <wenqing.lz@...bao.com>, "Theodore Ts'o" <tytso@....edu>,
	Jan kara <jack@...e.cz>
Subject: [PATCH 03/10 v5] ext4: let ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag

From: Zheng Liu <wenqing.lz@...bao.com>

This commit lets ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag
because in later commit ext4_map_blocks needs to use this flag to
determine the extent status.

Signed-off-by: Zheng Liu <wenqing.lz@...bao.com>
Cc: "Theodore Ts'o" <tytso@....edu>
Cc: Jan kara <jack@...e.cz>
---
 fs/ext4/extents.c |  6 +++++-
 fs/ext4/inode.c   | 12 +++---------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index f7bf616..d92947f 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3657,6 +3657,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
 			ext4_set_io_unwritten_flag(inode, io);
 		else
 			ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
+		map->m_flags |= EXT4_MAP_UNWRITTEN;
 		if (ext4_should_dioread_nolock(inode))
 			map->m_flags |= EXT4_MAP_UNINIT;
 		goto out;
@@ -3678,8 +3679,10 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
 	 * repeat fallocate creation request
 	 * we already have an unwritten extent
 	 */
-	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
+	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) {
+		map->m_flags |= EXT4_MAP_UNWRITTEN;
 		goto map_out;
+	}
 
 	/* buffered READ or buffered write_begin() lookup */
 	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
@@ -4109,6 +4112,7 @@ got_allocated_blocks:
 	/* Mark uninitialized */
 	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
 		ext4_ext_mark_uninitialized(&newex);
+		map->m_flags |= EXT4_MAP_UNWRITTEN;
 		/*
 		 * io_end structure was created for every IO write to an
 		 * uninitialized extent. To avoid unnecessary conversion,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7fb00d8..c7e9665 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -560,16 +560,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 		return retval;
 
 	/*
-	 * When we call get_blocks without the create flag, the
-	 * BH_Unwritten flag could have gotten set if the blocks
-	 * requested were part of a uninitialized extent.  We need to
-	 * clear this flag now that we are committed to convert all or
-	 * part of the uninitialized extent to be an initialized
-	 * extent.  This is because we need to avoid the combination
-	 * of BH_Unwritten and BH_Mapped flags being simultaneously
-	 * set on the buffer_head.
+	 * Here we clear m_flags because after allocating an new extent,
+	 * it will be set again.
 	 */
-	map->m_flags &= ~EXT4_MAP_UNWRITTEN;
+	map->m_flags &= ~EXT4_MAP_FLAGS;
 
 	/*
 	 * New blocks allocate and/or writing to uninitialized extent
-- 
1.7.12.rc2.18.g61b472e

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