[PATCH 7/7] LSEEK: BTRFS: Avoid i_mutex for SEEK_{CUR,SET,END}

[Andi Kleen <andi@firstfloor.org>]

From: Andi Kleen <ak@linux.intel.com>

Don't need the i_mutex for those cases, only for SEEK_HOLE/DATA.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 fs/btrfs/file.c |   18 ++++++------------
 1 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 62f56d4..ae7f37e 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1809,18 +1809,13 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
 	struct inode *inode = file->f_mapping->host;
 	int ret;
 
+	if (origin != SEEK_DATA && origin != SEEK_HOLE)
+		return generic_file_llseek(file, offset, origin);
+
 	mutex_lock(&inode->i_mutex);
-	switch (origin) {
-	case SEEK_END:
-	case SEEK_CUR:
-		offset = generic_file_llseek(file, offset, origin);
-		goto out;
-	case SEEK_DATA:
-	case SEEK_HOLE:
-		ret = find_desired_extent(inode, &offset, origin);
-		if (ret)
-			goto error;
-	}
+	ret = find_desired_extent(inode, &offset, origin);
+	if (ret)
+		goto error;
 
 	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
 		ret = -EINVAL;
@@ -1836,7 +1831,6 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
 		file->f_pos = offset;
 		file->f_version = 0;
 	}
-out:
 	mutex_unlock(&inode->i_mutex);
 	return offset;
 error:
-- 
1.7.4.4