[ 39/71] udf: dont increment lenExtents while writing to a hole

From: Greg Kroah-Hartman
Date: Tue Jan 15 2013 - 18:06:09 EST


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

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

From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>

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@xxxxxxxxxxx>
Signed-off-by: Ashish Sangwan <a.sangwan@xxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Shuah Khan <shuah.khan@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/udf/inode.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -575,6 +575,7 @@ static struct buffer_head *inode_getblk(
struct udf_inode_info *iinfo = UDF_I(inode);
int goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
int lastblock = 0;
+ bool isBeyondEOF;

prev_epos.offset = udf_file_entry_alloc_offset(inode);
prev_epos.block = iinfo->i_location;
@@ -653,7 +654,7 @@ static struct buffer_head *inode_getblk(
/* Are we beyond EOF? */
if (etype == -1) {
int ret;
-
+ isBeyondEOF = 1;
if (count) {
if (c)
laarr[0] = laarr[1];
@@ -696,6 +697,7 @@ static struct buffer_head *inode_getblk(
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 struct buffer_head *inode_getblk(
*err = -ENOSPC;
return NULL;
}
- 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


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