From: Theodore Ts'o <tytso@mit.edu>
Date: Wed, 12 Jun 2013 15:48:29 +0000 (-0400)
Subject: ext4: don't use EXT4_FREE_BLOCKS_FORGET unnecessarily
X-Git-Tag: next-20130617~97^2~11
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c1b472275748299749a958dd195ead9e9c361e19;p=karo-tx-linux.git

ext4: don't use EXT4_FREE_BLOCKS_FORGET unnecessarily

Commit 18888cf0883c: "ext4: speed up truncate/unlink by not using
bforget() unless needed" removed the use of EXT4_FREE_BLOCKS_FORGET in
the most important codepath for file systems using extents, but a
similar optimization also can be done for file systems using indirect
blocks, and for the two special cases in the ext4 extents code.

Cc: Andrey Sidorov <qrxd43@motorola.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 208f664f9ee0..d04f40936397 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2355,6 +2355,15 @@ int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
 	return index;
 }
 
+static inline int get_default_free_blocks_flags(struct inode *inode)
+{
+	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+		return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
+	else if (ext4_should_journal_data(inode))
+		return EXT4_FREE_BLOCKS_FORGET;
+	return 0;
+}
+
 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 			      struct ext4_extent *ex,
 			      long long *partial_cluster,
@@ -2363,12 +2372,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	unsigned short ee_len =  ext4_ext_get_actual_len(ex);
 	ext4_fsblk_t pblk;
-	int flags = 0;
-
-	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		flags |= EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
-	else if (ext4_should_journal_data(inode))
-		flags |= EXT4_FREE_BLOCKS_FORGET;
+	int flags = get_default_free_blocks_flags(inode);
 
 	/*
 	 * For bigalloc file systems, we never free a partial cluster
@@ -2635,10 +2639,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 	if (*partial_cluster > 0 &&
 	    (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
 	     *partial_cluster)) {
-		int flags = EXT4_FREE_BLOCKS_FORGET;
-
-		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-			flags |= EXT4_FREE_BLOCKS_METADATA;
+		int flags = get_default_free_blocks_flags(inode);
 
 		ext4_free_blocks(handle, inode, NULL,
 				 EXT4_C2B(sbi, *partial_cluster),
@@ -2869,10 +2870,7 @@ again:
 	 * even the first extent, then we should free the blocks in the partial
 	 * cluster as well. */
 	if (partial_cluster > 0 && path->p_hdr->eh_entries == 0) {
-		int flags = EXT4_FREE_BLOCKS_FORGET;
-
-		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-			flags |= EXT4_FREE_BLOCKS_METADATA;
+		int flags = get_default_free_blocks_flags(inode);
 
 		ext4_free_blocks(handle, inode, NULL,
 				 EXT4_C2B(EXT4_SB(sb), partial_cluster),
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 2a1f8a577e08..963d23dc1028 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -926,11 +926,13 @@ static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
 			     __le32 *last)
 {
 	__le32 *p;
-	int	flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
+	int	flags = EXT4_FREE_BLOCKS_VALIDATED;
 	int	err;
 
 	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		flags |= EXT4_FREE_BLOCKS_METADATA;
+		flags |= EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_METADATA;
+	else if (ext4_should_journal_data(inode))
+		flags |= EXT4_FREE_BLOCKS_FORGET;
 
 	if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
 				   count)) {