[PATCH 157/222] udf: don't increment lenExtents while writing to a hole

[Herton Ronaldo Krzesinski]

3.5.7.3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Namjae Jeon <namjae.jeon at samsung.com>

commit fb719c59bdb4fca86ee1fd1f42ab3735ca12b6b2 upstream.

Incrementing lenExtents even while writing to a hole is bad
for performance as calls to udf_discard_prealloc and
udf_truncate_tail_extent would not return from start if
isize != lenExtents

Signed-off-by: Namjae Jeon <namjae.jeon at samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan at samsung.com>
Signed-off-by: Jan Kara <jack at suse.cz>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 fs/udf/inode.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 8873c47..fb65df5 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -574,6 +574,7 @@ static sector_t inode_getblk(struct inode *inode, sector_t block,
 	struct udf_inode_info *iinfo = UDF_I(inode);
 	int goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
 	int lastblock = 0;
+	bool isBeyondEOF;
 
 	*err = 0;
 	*new = 0;
@@ -653,7 +654,7 @@ static sector_t inode_getblk(struct inode *inode, sector_t block,
 	/* Are we beyond EOF? */
 	if (etype == -1) {
 		int ret;
-
+		isBeyondEOF = 1;
 		if (count) {
 			if (c)
 				laarr[0] = laarr[1];
@@ -696,6 +697,7 @@ static sector_t inode_getblk(struct inode *inode, sector_t block,
 		endnum = c + 1;
 		lastblock = 1;
 	} else {
+		isBeyondEOF = 0;
 		endnum = startnum = ((count > 2) ? 2 : count);
 
 		/* if the current extent is in position 0,
@@ -743,7 +745,8 @@ static sector_t inode_getblk(struct inode *inode, sector_t block,
 			*err = -ENOSPC;
 			return 0;
 		}
-		iinfo->i_lenExtents += inode->i_sb->s_blocksize;
+		if (isBeyondEOF)
+			iinfo->i_lenExtents += inode->i_sb->s_blocksize;
 	}
 
 	/* if the extent the requsted block is located in contains multiple
-- 
1.7.9.5